Hi Luis,
As per your suggestion [1], this is an attempt to refactor and split
optional code out of core module support code into separate components.
This version is based on Linus' commit 7993e65fdd0f ("Merge tag
'mtd/fixes-for-5.17-rc5' of
git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux").
Changes since v9 [2]
- Updated MAINTAINERS to include kernel/module/livepatch.c
and kernel/module/kdb.c, respectively
- Moved kdb module related code i.e. support for the 'lsmod',
out of core/or main kdb code into its own file under
kernel/module
- Ensured is_module_sig_enforced(), as a stub, is available
when Kconfig CONFIG_MODULE_SIG is not enabled/or selected
(Christophe Leroy)
Changes since v8 [3]
- Resolved the reported lockdep warnings in kernel/module/kallsyms.c
(Petr Mladek)
Changes since v7 [4]
- Removed redundant ifdef CONFIG_MODULES and endif pairing from
kernel/module/Makefile
Changes since v6 [5]
- Moved KCOV_INSTRUMENT_module.o out of kernel/Makefile into
kernel/module/Makefile (Christophe Leroy)
- Moved kernel/module/signature.c back into kernel/
(Christophe Leroy)
- Fixed Oops in add_kallsyms() due to an invalid pointer assignment
(Christophe Leroy)
Changes since v5 [6]:
- Updated MAINTAINERS to include the entire kernel/module/ directory
(Christophe Leroy)
- Reintroduce commit a97ac8cb24a3 ("module: fix signature check failures
when using in-kernel decompression") (Michal Suchánek)
- Refactored code to address some (i.e.
--ignore=MULTIPLE_ASSIGNMENTS,ASSIGN_IN_IF was used) style violations
e.g. "Alignment should match open parenthesis", reported by
scripts/checkpatch.pl --strict (Christophe Leroy)
- Used PAGE_ALIGN() and PAGE_ALIGNED() instead (Christophe Leroy)
- Removed sig_enforce from include/linux/module.h as it is only
used in kernel/module/signing.c (Christophe Leroy)
- Added static keyword for anything not used outside a source file
(Christophe Leroy)
- Moved mod_sysfs_teardown() to kernel/module/sysfs.c (Christophe Leroy)
- Removed kdb_modules from kernel/debug/kdb/kdb_private.h
(Christophe Leroy)
Changes since v4 [7]:
- Moved is_livepatch_module() and set_livepatch_module() to
kernel/module/livepatch.c
- Addressed minor compiler warning concerning
kernel/module/internal.h (0-day)
- Resolved style violations reported by scripts/checkpatch.pl
- Dropped patch 5 [8] so external patch [9] can be applied at
a later date post merge into module-next (Christophe Leroy)
Changes since v3 [10]:
- Refactored both is_livepatch_module() and set_livepatch_module(),
respectively, to use IS_ENABLED(CONFIG_LIVEPATCH) (Joe Perches)
- Addressed various compiler warnings e.g., no previous prototype (0-day)
Changes since v2 [11]:
- Moved module decompress support to a separate file
- Made check_modinfo_livepatch() generic (Petr Mladek)
- Removed filename from each newly created file (Luis Chamberlain)
- Addressed some (i.e. --ignore=ASSIGN_IN_IF,AVOID_BUG was used)
minor scripts/checkpatch.pl concerns e.g., use strscpy over
strlcpy and missing a blank line after declarations (Allen)
Changes since v1 [12]:
- Moved module version support code into a new file
[1]: https://lore.kernel.org/lkml/[email protected]/
[2]: https://lore.kernel.org/lkml/[email protected]/
[3]: https://lore.kernel.org/all/[email protected]/
[4]: https://lore.kernel.org/lkml/[email protected]/
[5]: https://lore.kernel.org/lkml/[email protected]/
[6]: https://lore.kernel.org/lkml/[email protected]/
[7]: https://lore.kernel.org/lkml/[email protected]/
[8]: https://lore.kernel.org/lkml/[email protected]/
[9]: https://lore.kernel.org/lkml/203348805c9ac9851d8939d15cb9802ef047b5e2.1643919758.git.christophe.leroy@csgroup.eu/
[10]: https://lore.kernel.org/lkml/[email protected]/
[11]: https://lore.kernel.org/lkml/[email protected]/
[12]: https://lore.kernel.org/lkml/[email protected]/
Aaron Tomlin (14):
module: Move all into module/
module: Simple refactor in preparation for split
module: Make internal.h and decompress.c more compliant
module: Move livepatch support to a separate file
module: Move latched RB-tree support to a separate file
module: Move strict rwx support to a separate file
module: Move extra signature support out of core code
module: Move kmemleak support to a separate file
module: Move kallsyms support into a separate file
module: kallsyms: Fix suspicious rcu usage
module: Move procfs support into a separate file
module: Move sysfs support into a separate file
module: Move kdb module related code out of main kdb code
module: Move version support into a separate file
MAINTAINERS | 4 +-
include/linux/kdb.h | 1 +
include/linux/module.h | 21 +-
kernel/Makefile | 5 +-
kernel/debug/kdb/kdb_main.c | 49 -
kernel/module-internal.h | 50 -
kernel/module/Makefile | 21 +
kernel/module/debug_kmemleak.c | 30 +
.../decompress.c} | 5 +-
kernel/module/internal.h | 275 +++
kernel/module/kallsyms.c | 512 +++++
kernel/module/kdb.c | 55 +
kernel/module/livepatch.c | 74 +
kernel/{module.c => module/main.c} | 1856 +----------------
kernel/module/procfs.c | 142 ++
kernel/module/signing.c | 122 ++
kernel/module/strict_rwx.c | 85 +
kernel/module/sysfs.c | 436 ++++
kernel/module/tree_lookup.c | 109 +
kernel/module/version.c | 109 +
kernel/module_signing.c | 45 -
21 files changed, 2074 insertions(+), 1932 deletions(-)
delete mode 100644 kernel/module-internal.h
create mode 100644 kernel/module/Makefile
create mode 100644 kernel/module/debug_kmemleak.c
rename kernel/{module_decompress.c => module/decompress.c} (99%)
create mode 100644 kernel/module/internal.h
create mode 100644 kernel/module/kallsyms.c
create mode 100644 kernel/module/kdb.c
create mode 100644 kernel/module/livepatch.c
rename kernel/{module.c => module/main.c} (64%)
create mode 100644 kernel/module/procfs.c
create mode 100644 kernel/module/signing.c
create mode 100644 kernel/module/strict_rwx.c
create mode 100644 kernel/module/sysfs.c
create mode 100644 kernel/module/tree_lookup.c
create mode 100644 kernel/module/version.c
delete mode 100644 kernel/module_signing.c
base-commit: 7993e65fdd0fe07beb9f36f998f9bbef2c0ee391
--
2.34.1
No functional change.
This patch migrates module sysfs support out of core code into
kernel/module/sysfs.c. In addition simple code refactoring to
make this possible.
Reviewed-by: Christophe Leroy <[email protected]>
Signed-off-by: Aaron Tomlin <[email protected]>
---
kernel/module/Makefile | 1 +
kernel/module/internal.h | 21 ++
kernel/module/main.c | 469 +--------------------------------------
kernel/module/sysfs.c | 436 ++++++++++++++++++++++++++++++++++++
4 files changed, 461 insertions(+), 466 deletions(-)
create mode 100644 kernel/module/sysfs.c
diff --git a/kernel/module/Makefile b/kernel/module/Makefile
index 94296c98a67f..cf8dcdc6b55f 100644
--- a/kernel/module/Makefile
+++ b/kernel/module/Makefile
@@ -16,3 +16,4 @@ obj-$(CONFIG_STRICT_MODULE_RWX) += strict_rwx.o
obj-$(CONFIG_DEBUG_KMEMLEAK) += debug_kmemleak.o
obj-$(CONFIG_KALLSYMS) += kallsyms.o
obj-$(CONFIG_PROC_FS) += procfs.o
+obj-$(CONFIG_SYSFS) += sysfs.o
diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index 6af40c2d145f..62d749ef695e 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -34,6 +34,9 @@
extern struct mutex module_mutex;
extern struct list_head modules;
+extern struct module_attribute *modinfo_attrs[];
+extern size_t modinfo_attrs_count;
+
/* Provided by the linker */
extern const struct kernel_symbol __start___ksymtab[];
extern const struct kernel_symbol __stop___ksymtab[];
@@ -204,3 +207,21 @@ static inline void init_build_id(struct module *mod, const struct load_info *inf
static inline void layout_symtab(struct module *mod, struct load_info *info) { }
static inline void add_kallsyms(struct module *mod, const struct load_info *info) { }
#endif /* CONFIG_KALLSYMS */
+
+#ifdef CONFIG_SYSFS
+int mod_sysfs_setup(struct module *mod, const struct load_info *info,
+ struct kernel_param *kparam, unsigned int num_params);
+void mod_sysfs_teardown(struct module *mod);
+void init_param_lock(struct module *mod);
+#else /* !CONFIG_SYSFS */
+static inline int mod_sysfs_setup(struct module *mod,
+ const struct load_info *info,
+ struct kernel_param *kparam,
+ unsigned int num_params)
+{
+ return 0;
+}
+
+static inline void mod_sysfs_teardown(struct module *mod) { }
+static inline void init_param_lock(struct module *mod) { }
+#endif /* CONFIG_SYSFS */
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 44b6fd1acc44..b8a59b5c3e3a 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -14,9 +14,7 @@
#include <linux/init.h>
#include <linux/kallsyms.h>
#include <linux/buildid.h>
-#include <linux/file.h>
#include <linux/fs.h>
-#include <linux/sysfs.h>
#include <linux/kernel.h>
#include <linux/kernel_read_file.h>
#include <linux/slab.h>
@@ -989,7 +987,7 @@ static ssize_t show_taint(struct module_attribute *mattr,
static struct module_attribute modinfo_taint =
__ATTR(taint, 0444, show_taint, NULL);
-static struct module_attribute *modinfo_attrs[] = {
+struct module_attribute *modinfo_attrs[] = {
&module_uevent,
&modinfo_version,
&modinfo_srcversion,
@@ -1003,6 +1001,8 @@ static struct module_attribute *modinfo_attrs[] = {
NULL,
};
+size_t modinfo_attrs_count = ARRAY_SIZE(modinfo_attrs);
+
static const char vermagic[] = VERMAGIC_STRING;
static int try_to_force_load(struct module *mod, const char *reason)
@@ -1253,469 +1253,6 @@ resolve_symbol_wait(struct module *mod,
return ksym;
}
-/*
- * /sys/module/foo/sections stuff
- * J. Corbet <[email protected]>
- */
-#ifdef CONFIG_SYSFS
-
-#ifdef CONFIG_KALLSYMS
-struct module_sect_attr {
- struct bin_attribute battr;
- unsigned long address;
-};
-
-struct module_sect_attrs {
- struct attribute_group grp;
- unsigned int nsections;
- struct module_sect_attr attrs[];
-};
-
-#define MODULE_SECT_READ_SIZE (3 /* "0x", "\n" */ + (BITS_PER_LONG / 4))
-static ssize_t module_sect_read(struct file *file, struct kobject *kobj,
- struct bin_attribute *battr,
- char *buf, loff_t pos, size_t count)
-{
- struct module_sect_attr *sattr =
- container_of(battr, struct module_sect_attr, battr);
- char bounce[MODULE_SECT_READ_SIZE + 1];
- size_t wrote;
-
- if (pos != 0)
- return -EINVAL;
-
- /*
- * Since we're a binary read handler, we must account for the
- * trailing NUL byte that sprintf will write: if "buf" is
- * too small to hold the NUL, or the NUL is exactly the last
- * byte, the read will look like it got truncated by one byte.
- * Since there is no way to ask sprintf nicely to not write
- * the NUL, we have to use a bounce buffer.
- */
- wrote = scnprintf(bounce, sizeof(bounce), "0x%px\n",
- kallsyms_show_value(file->f_cred)
- ? (void *)sattr->address : NULL);
- count = min(count, wrote);
- memcpy(buf, bounce, count);
-
- return count;
-}
-
-static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
-{
- unsigned int section;
-
- for (section = 0; section < sect_attrs->nsections; section++)
- kfree(sect_attrs->attrs[section].battr.attr.name);
- kfree(sect_attrs);
-}
-
-static void add_sect_attrs(struct module *mod, const struct load_info *info)
-{
- unsigned int nloaded = 0, i, size[2];
- struct module_sect_attrs *sect_attrs;
- struct module_sect_attr *sattr;
- struct bin_attribute **gattr;
-
- /* Count loaded sections and allocate structures */
- for (i = 0; i < info->hdr->e_shnum; i++)
- if (!sect_empty(&info->sechdrs[i]))
- nloaded++;
- size[0] = ALIGN(struct_size(sect_attrs, attrs, nloaded),
- sizeof(sect_attrs->grp.bin_attrs[0]));
- size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.bin_attrs[0]);
- sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
- if (sect_attrs == NULL)
- return;
-
- /* Setup section attributes. */
- sect_attrs->grp.name = "sections";
- sect_attrs->grp.bin_attrs = (void *)sect_attrs + size[0];
-
- sect_attrs->nsections = 0;
- sattr = §_attrs->attrs[0];
- gattr = §_attrs->grp.bin_attrs[0];
- for (i = 0; i < info->hdr->e_shnum; i++) {
- Elf_Shdr *sec = &info->sechdrs[i];
- if (sect_empty(sec))
- continue;
- sysfs_bin_attr_init(&sattr->battr);
- sattr->address = sec->sh_addr;
- sattr->battr.attr.name =
- kstrdup(info->secstrings + sec->sh_name, GFP_KERNEL);
- if (sattr->battr.attr.name == NULL)
- goto out;
- sect_attrs->nsections++;
- sattr->battr.read = module_sect_read;
- sattr->battr.size = MODULE_SECT_READ_SIZE;
- sattr->battr.attr.mode = 0400;
- *(gattr++) = &(sattr++)->battr;
- }
- *gattr = NULL;
-
- if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp))
- goto out;
-
- mod->sect_attrs = sect_attrs;
- return;
- out:
- free_sect_attrs(sect_attrs);
-}
-
-static void remove_sect_attrs(struct module *mod)
-{
- if (mod->sect_attrs) {
- sysfs_remove_group(&mod->mkobj.kobj,
- &mod->sect_attrs->grp);
- /*
- * We are positive that no one is using any sect attrs
- * at this point. Deallocate immediately.
- */
- free_sect_attrs(mod->sect_attrs);
- mod->sect_attrs = NULL;
- }
-}
-
-/*
- * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
- */
-
-struct module_notes_attrs {
- struct kobject *dir;
- unsigned int notes;
- struct bin_attribute attrs[];
-};
-
-static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
- struct bin_attribute *bin_attr,
- char *buf, loff_t pos, size_t count)
-{
- /*
- * The caller checked the pos and count against our size.
- */
- memcpy(buf, bin_attr->private + pos, count);
- return count;
-}
-
-static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
- unsigned int i)
-{
- if (notes_attrs->dir) {
- while (i-- > 0)
- sysfs_remove_bin_file(notes_attrs->dir,
- ¬es_attrs->attrs[i]);
- kobject_put(notes_attrs->dir);
- }
- kfree(notes_attrs);
-}
-
-static void add_notes_attrs(struct module *mod, const struct load_info *info)
-{
- unsigned int notes, loaded, i;
- struct module_notes_attrs *notes_attrs;
- struct bin_attribute *nattr;
-
- /* failed to create section attributes, so can't create notes */
- if (!mod->sect_attrs)
- return;
-
- /* Count notes sections and allocate structures. */
- notes = 0;
- for (i = 0; i < info->hdr->e_shnum; i++)
- if (!sect_empty(&info->sechdrs[i]) &&
- (info->sechdrs[i].sh_type == SHT_NOTE))
- ++notes;
-
- if (notes == 0)
- return;
-
- notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes),
- GFP_KERNEL);
- if (notes_attrs == NULL)
- return;
-
- notes_attrs->notes = notes;
- nattr = ¬es_attrs->attrs[0];
- for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
- if (sect_empty(&info->sechdrs[i]))
- continue;
- if (info->sechdrs[i].sh_type == SHT_NOTE) {
- sysfs_bin_attr_init(nattr);
- nattr->attr.name = mod->sect_attrs->attrs[loaded].battr.attr.name;
- nattr->attr.mode = S_IRUGO;
- nattr->size = info->sechdrs[i].sh_size;
- nattr->private = (void *) info->sechdrs[i].sh_addr;
- nattr->read = module_notes_read;
- ++nattr;
- }
- ++loaded;
- }
-
- notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
- if (!notes_attrs->dir)
- goto out;
-
- for (i = 0; i < notes; ++i)
- if (sysfs_create_bin_file(notes_attrs->dir,
- ¬es_attrs->attrs[i]))
- goto out;
-
- mod->notes_attrs = notes_attrs;
- return;
-
- out:
- free_notes_attrs(notes_attrs, i);
-}
-
-static void remove_notes_attrs(struct module *mod)
-{
- if (mod->notes_attrs)
- free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
-}
-
-#else
-
-static inline void add_sect_attrs(struct module *mod,
- const struct load_info *info)
-{
-}
-
-static inline void remove_sect_attrs(struct module *mod)
-{
-}
-
-static inline void add_notes_attrs(struct module *mod,
- const struct load_info *info)
-{
-}
-
-static inline void remove_notes_attrs(struct module *mod)
-{
-}
-#endif /* CONFIG_KALLSYMS */
-
-static void del_usage_links(struct module *mod)
-{
-#ifdef CONFIG_MODULE_UNLOAD
- struct module_use *use;
-
- mutex_lock(&module_mutex);
- list_for_each_entry(use, &mod->target_list, target_list)
- sysfs_remove_link(use->target->holders_dir, mod->name);
- mutex_unlock(&module_mutex);
-#endif
-}
-
-static int add_usage_links(struct module *mod)
-{
- int ret = 0;
-#ifdef CONFIG_MODULE_UNLOAD
- struct module_use *use;
-
- mutex_lock(&module_mutex);
- list_for_each_entry(use, &mod->target_list, target_list) {
- ret = sysfs_create_link(use->target->holders_dir,
- &mod->mkobj.kobj, mod->name);
- if (ret)
- break;
- }
- mutex_unlock(&module_mutex);
- if (ret)
- del_usage_links(mod);
-#endif
- return ret;
-}
-
-static void module_remove_modinfo_attrs(struct module *mod, int end);
-
-static int module_add_modinfo_attrs(struct module *mod)
-{
- struct module_attribute *attr;
- struct module_attribute *temp_attr;
- int error = 0;
- int i;
-
- mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
- (ARRAY_SIZE(modinfo_attrs) + 1)),
- GFP_KERNEL);
- if (!mod->modinfo_attrs)
- return -ENOMEM;
-
- temp_attr = mod->modinfo_attrs;
- for (i = 0; (attr = modinfo_attrs[i]); i++) {
- if (!attr->test || attr->test(mod)) {
- memcpy(temp_attr, attr, sizeof(*temp_attr));
- sysfs_attr_init(&temp_attr->attr);
- error = sysfs_create_file(&mod->mkobj.kobj,
- &temp_attr->attr);
- if (error)
- goto error_out;
- ++temp_attr;
- }
- }
-
- return 0;
-
-error_out:
- if (i > 0)
- module_remove_modinfo_attrs(mod, --i);
- else
- kfree(mod->modinfo_attrs);
- return error;
-}
-
-static void module_remove_modinfo_attrs(struct module *mod, int end)
-{
- struct module_attribute *attr;
- int i;
-
- for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
- if (end >= 0 && i > end)
- break;
- /* pick a field to test for end of list */
- if (!attr->attr.name)
- break;
- sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
- if (attr->free)
- attr->free(mod);
- }
- kfree(mod->modinfo_attrs);
-}
-
-static void mod_kobject_put(struct module *mod)
-{
- DECLARE_COMPLETION_ONSTACK(c);
- mod->mkobj.kobj_completion = &c;
- kobject_put(&mod->mkobj.kobj);
- wait_for_completion(&c);
-}
-
-static int mod_sysfs_init(struct module *mod)
-{
- int err;
- struct kobject *kobj;
-
- if (!module_sysfs_initialized) {
- pr_err("%s: module sysfs not initialized\n", mod->name);
- err = -EINVAL;
- goto out;
- }
-
- kobj = kset_find_obj(module_kset, mod->name);
- if (kobj) {
- pr_err("%s: module is already loaded\n", mod->name);
- kobject_put(kobj);
- err = -EINVAL;
- goto out;
- }
-
- mod->mkobj.mod = mod;
-
- memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
- mod->mkobj.kobj.kset = module_kset;
- err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
- "%s", mod->name);
- if (err)
- mod_kobject_put(mod);
-
-out:
- return err;
-}
-
-static int mod_sysfs_setup(struct module *mod,
- const struct load_info *info,
- struct kernel_param *kparam,
- unsigned int num_params)
-{
- int err;
-
- err = mod_sysfs_init(mod);
- if (err)
- goto out;
-
- mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
- if (!mod->holders_dir) {
- err = -ENOMEM;
- goto out_unreg;
- }
-
- err = module_param_sysfs_setup(mod, kparam, num_params);
- if (err)
- goto out_unreg_holders;
-
- err = module_add_modinfo_attrs(mod);
- if (err)
- goto out_unreg_param;
-
- err = add_usage_links(mod);
- if (err)
- goto out_unreg_modinfo_attrs;
-
- add_sect_attrs(mod, info);
- add_notes_attrs(mod, info);
-
- return 0;
-
-out_unreg_modinfo_attrs:
- module_remove_modinfo_attrs(mod, -1);
-out_unreg_param:
- module_param_sysfs_remove(mod);
-out_unreg_holders:
- kobject_put(mod->holders_dir);
-out_unreg:
- mod_kobject_put(mod);
-out:
- return err;
-}
-
-static void mod_sysfs_fini(struct module *mod)
-{
- remove_notes_attrs(mod);
- remove_sect_attrs(mod);
- mod_kobject_put(mod);
-}
-
-static void init_param_lock(struct module *mod)
-{
- mutex_init(&mod->param_lock);
-}
-#else /* !CONFIG_SYSFS */
-
-static int mod_sysfs_setup(struct module *mod,
- const struct load_info *info,
- struct kernel_param *kparam,
- unsigned int num_params)
-{
- return 0;
-}
-
-static void mod_sysfs_fini(struct module *mod)
-{
-}
-
-static void module_remove_modinfo_attrs(struct module *mod, int end)
-{
-}
-
-static void del_usage_links(struct module *mod)
-{
-}
-
-static void init_param_lock(struct module *mod)
-{
-}
-#endif /* CONFIG_SYSFS */
-
-static void mod_sysfs_teardown(struct module *mod)
-{
- del_usage_links(mod);
- module_remove_modinfo_attrs(mod, -1);
- module_param_sysfs_remove(mod);
- kobject_put(mod->mkobj.drivers_dir);
- kobject_put(mod->holders_dir);
- mod_sysfs_fini(mod);
-}
-
/*
* LKM RO/NX protection: protect module's text/ro-data
* from modification and any data from execution.
diff --git a/kernel/module/sysfs.c b/kernel/module/sysfs.c
new file mode 100644
index 000000000000..ce68f821dcd1
--- /dev/null
+++ b/kernel/module/sysfs.c
@@ -0,0 +1,436 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Module sysfs support
+ *
+ * Copyright (C) 2008 Rusty Russell
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/sysfs.h>
+#include <linux/slab.h>
+#include <linux/kallsyms.h>
+#include <linux/mutex.h>
+#include "internal.h"
+
+/*
+ * /sys/module/foo/sections stuff
+ * J. Corbet <[email protected]>
+ */
+#ifdef CONFIG_KALLSYMS
+struct module_sect_attr {
+ struct bin_attribute battr;
+ unsigned long address;
+};
+
+struct module_sect_attrs {
+ struct attribute_group grp;
+ unsigned int nsections;
+ struct module_sect_attr attrs[];
+};
+
+#define MODULE_SECT_READ_SIZE (3 /* "0x", "\n" */ + (BITS_PER_LONG / 4))
+static ssize_t module_sect_read(struct file *file, struct kobject *kobj,
+ struct bin_attribute *battr,
+ char *buf, loff_t pos, size_t count)
+{
+ struct module_sect_attr *sattr =
+ container_of(battr, struct module_sect_attr, battr);
+ char bounce[MODULE_SECT_READ_SIZE + 1];
+ size_t wrote;
+
+ if (pos != 0)
+ return -EINVAL;
+
+ /*
+ * Since we're a binary read handler, we must account for the
+ * trailing NUL byte that sprintf will write: if "buf" is
+ * too small to hold the NUL, or the NUL is exactly the last
+ * byte, the read will look like it got truncated by one byte.
+ * Since there is no way to ask sprintf nicely to not write
+ * the NUL, we have to use a bounce buffer.
+ */
+ wrote = scnprintf(bounce, sizeof(bounce), "0x%px\n",
+ kallsyms_show_value(file->f_cred)
+ ? (void *)sattr->address : NULL);
+ count = min(count, wrote);
+ memcpy(buf, bounce, count);
+
+ return count;
+}
+
+static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
+{
+ unsigned int section;
+
+ for (section = 0; section < sect_attrs->nsections; section++)
+ kfree(sect_attrs->attrs[section].battr.attr.name);
+ kfree(sect_attrs);
+}
+
+static void add_sect_attrs(struct module *mod, const struct load_info *info)
+{
+ unsigned int nloaded = 0, i, size[2];
+ struct module_sect_attrs *sect_attrs;
+ struct module_sect_attr *sattr;
+ struct bin_attribute **gattr;
+
+ /* Count loaded sections and allocate structures */
+ for (i = 0; i < info->hdr->e_shnum; i++)
+ if (!sect_empty(&info->sechdrs[i]))
+ nloaded++;
+ size[0] = ALIGN(struct_size(sect_attrs, attrs, nloaded),
+ sizeof(sect_attrs->grp.bin_attrs[0]));
+ size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.bin_attrs[0]);
+ sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
+ if (!sect_attrs)
+ return;
+
+ /* Setup section attributes. */
+ sect_attrs->grp.name = "sections";
+ sect_attrs->grp.bin_attrs = (void *)sect_attrs + size[0];
+
+ sect_attrs->nsections = 0;
+ sattr = §_attrs->attrs[0];
+ gattr = §_attrs->grp.bin_attrs[0];
+ for (i = 0; i < info->hdr->e_shnum; i++) {
+ Elf_Shdr *sec = &info->sechdrs[i];
+
+ if (sect_empty(sec))
+ continue;
+ sysfs_bin_attr_init(&sattr->battr);
+ sattr->address = sec->sh_addr;
+ sattr->battr.attr.name =
+ kstrdup(info->secstrings + sec->sh_name, GFP_KERNEL);
+ if (!sattr->battr.attr.name)
+ goto out;
+ sect_attrs->nsections++;
+ sattr->battr.read = module_sect_read;
+ sattr->battr.size = MODULE_SECT_READ_SIZE;
+ sattr->battr.attr.mode = 0400;
+ *(gattr++) = &(sattr++)->battr;
+ }
+ *gattr = NULL;
+
+ if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp))
+ goto out;
+
+ mod->sect_attrs = sect_attrs;
+ return;
+out:
+ free_sect_attrs(sect_attrs);
+}
+
+static void remove_sect_attrs(struct module *mod)
+{
+ if (mod->sect_attrs) {
+ sysfs_remove_group(&mod->mkobj.kobj,
+ &mod->sect_attrs->grp);
+ /*
+ * We are positive that no one is using any sect attrs
+ * at this point. Deallocate immediately.
+ */
+ free_sect_attrs(mod->sect_attrs);
+ mod->sect_attrs = NULL;
+ }
+}
+
+/*
+ * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
+ */
+
+struct module_notes_attrs {
+ struct kobject *dir;
+ unsigned int notes;
+ struct bin_attribute attrs[];
+};
+
+static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
+ struct bin_attribute *bin_attr,
+ char *buf, loff_t pos, size_t count)
+{
+ /*
+ * The caller checked the pos and count against our size.
+ */
+ memcpy(buf, bin_attr->private + pos, count);
+ return count;
+}
+
+static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
+ unsigned int i)
+{
+ if (notes_attrs->dir) {
+ while (i-- > 0)
+ sysfs_remove_bin_file(notes_attrs->dir,
+ ¬es_attrs->attrs[i]);
+ kobject_put(notes_attrs->dir);
+ }
+ kfree(notes_attrs);
+}
+
+static void add_notes_attrs(struct module *mod, const struct load_info *info)
+{
+ unsigned int notes, loaded, i;
+ struct module_notes_attrs *notes_attrs;
+ struct bin_attribute *nattr;
+
+ /* failed to create section attributes, so can't create notes */
+ if (!mod->sect_attrs)
+ return;
+
+ /* Count notes sections and allocate structures. */
+ notes = 0;
+ for (i = 0; i < info->hdr->e_shnum; i++)
+ if (!sect_empty(&info->sechdrs[i]) &&
+ info->sechdrs[i].sh_type == SHT_NOTE)
+ ++notes;
+
+ if (notes == 0)
+ return;
+
+ notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes),
+ GFP_KERNEL);
+ if (!notes_attrs)
+ return;
+
+ notes_attrs->notes = notes;
+ nattr = ¬es_attrs->attrs[0];
+ for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
+ if (sect_empty(&info->sechdrs[i]))
+ continue;
+ if (info->sechdrs[i].sh_type == SHT_NOTE) {
+ sysfs_bin_attr_init(nattr);
+ nattr->attr.name = mod->sect_attrs->attrs[loaded].battr.attr.name;
+ nattr->attr.mode = 0444;
+ nattr->size = info->sechdrs[i].sh_size;
+ nattr->private = (void *)info->sechdrs[i].sh_addr;
+ nattr->read = module_notes_read;
+ ++nattr;
+ }
+ ++loaded;
+ }
+
+ notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
+ if (!notes_attrs->dir)
+ goto out;
+
+ for (i = 0; i < notes; ++i)
+ if (sysfs_create_bin_file(notes_attrs->dir,
+ ¬es_attrs->attrs[i]))
+ goto out;
+
+ mod->notes_attrs = notes_attrs;
+ return;
+
+out:
+ free_notes_attrs(notes_attrs, i);
+}
+
+static void remove_notes_attrs(struct module *mod)
+{
+ if (mod->notes_attrs)
+ free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
+}
+
+#else /* !CONFIG_KALLSYMS */
+static inline void add_sect_attrs(struct module *mod, const struct load_info *info) { }
+static inline void remove_sect_attrs(struct module *mod) { }
+static inline void add_notes_attrs(struct module *mod, const struct load_info *info) { }
+static inline void remove_notes_attrs(struct module *mod) { }
+#endif /* CONFIG_KALLSYMS */
+
+static void del_usage_links(struct module *mod)
+{
+#ifdef CONFIG_MODULE_UNLOAD
+ struct module_use *use;
+
+ mutex_lock(&module_mutex);
+ list_for_each_entry(use, &mod->target_list, target_list)
+ sysfs_remove_link(use->target->holders_dir, mod->name);
+ mutex_unlock(&module_mutex);
+#endif
+}
+
+static int add_usage_links(struct module *mod)
+{
+ int ret = 0;
+#ifdef CONFIG_MODULE_UNLOAD
+ struct module_use *use;
+
+ mutex_lock(&module_mutex);
+ list_for_each_entry(use, &mod->target_list, target_list) {
+ ret = sysfs_create_link(use->target->holders_dir,
+ &mod->mkobj.kobj, mod->name);
+ if (ret)
+ break;
+ }
+ mutex_unlock(&module_mutex);
+ if (ret)
+ del_usage_links(mod);
+#endif
+ return ret;
+}
+
+static void module_remove_modinfo_attrs(struct module *mod, int end)
+{
+ struct module_attribute *attr;
+ int i;
+
+ for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
+ if (end >= 0 && i > end)
+ break;
+ /* pick a field to test for end of list */
+ if (!attr->attr.name)
+ break;
+ sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
+ if (attr->free)
+ attr->free(mod);
+ }
+ kfree(mod->modinfo_attrs);
+}
+
+static int module_add_modinfo_attrs(struct module *mod)
+{
+ struct module_attribute *attr;
+ struct module_attribute *temp_attr;
+ int error = 0;
+ int i;
+
+ mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
+ (modinfo_attrs_count + 1)),
+ GFP_KERNEL);
+ if (!mod->modinfo_attrs)
+ return -ENOMEM;
+
+ temp_attr = mod->modinfo_attrs;
+ for (i = 0; (attr = modinfo_attrs[i]); i++) {
+ if (!attr->test || attr->test(mod)) {
+ memcpy(temp_attr, attr, sizeof(*temp_attr));
+ sysfs_attr_init(&temp_attr->attr);
+ error = sysfs_create_file(&mod->mkobj.kobj,
+ &temp_attr->attr);
+ if (error)
+ goto error_out;
+ ++temp_attr;
+ }
+ }
+
+ return 0;
+
+error_out:
+ if (i > 0)
+ module_remove_modinfo_attrs(mod, --i);
+ else
+ kfree(mod->modinfo_attrs);
+ return error;
+}
+
+static void mod_kobject_put(struct module *mod)
+{
+ DECLARE_COMPLETION_ONSTACK(c);
+
+ mod->mkobj.kobj_completion = &c;
+ kobject_put(&mod->mkobj.kobj);
+ wait_for_completion(&c);
+}
+
+static int mod_sysfs_init(struct module *mod)
+{
+ int err;
+ struct kobject *kobj;
+
+ if (!module_sysfs_initialized) {
+ pr_err("%s: module sysfs not initialized\n", mod->name);
+ err = -EINVAL;
+ goto out;
+ }
+
+ kobj = kset_find_obj(module_kset, mod->name);
+ if (kobj) {
+ pr_err("%s: module is already loaded\n", mod->name);
+ kobject_put(kobj);
+ err = -EINVAL;
+ goto out;
+ }
+
+ mod->mkobj.mod = mod;
+
+ memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
+ mod->mkobj.kobj.kset = module_kset;
+ err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
+ "%s", mod->name);
+ if (err)
+ mod_kobject_put(mod);
+
+out:
+ return err;
+}
+
+int mod_sysfs_setup(struct module *mod,
+ const struct load_info *info,
+ struct kernel_param *kparam,
+ unsigned int num_params)
+{
+ int err;
+
+ err = mod_sysfs_init(mod);
+ if (err)
+ goto out;
+
+ mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
+ if (!mod->holders_dir) {
+ err = -ENOMEM;
+ goto out_unreg;
+ }
+
+ err = module_param_sysfs_setup(mod, kparam, num_params);
+ if (err)
+ goto out_unreg_holders;
+
+ err = module_add_modinfo_attrs(mod);
+ if (err)
+ goto out_unreg_param;
+
+ err = add_usage_links(mod);
+ if (err)
+ goto out_unreg_modinfo_attrs;
+
+ add_sect_attrs(mod, info);
+ add_notes_attrs(mod, info);
+
+ return 0;
+
+out_unreg_modinfo_attrs:
+ module_remove_modinfo_attrs(mod, -1);
+out_unreg_param:
+ module_param_sysfs_remove(mod);
+out_unreg_holders:
+ kobject_put(mod->holders_dir);
+out_unreg:
+ mod_kobject_put(mod);
+out:
+ return err;
+}
+
+static void mod_sysfs_fini(struct module *mod)
+{
+ remove_notes_attrs(mod);
+ remove_sect_attrs(mod);
+ mod_kobject_put(mod);
+}
+
+void mod_sysfs_teardown(struct module *mod)
+{
+ del_usage_links(mod);
+ module_remove_modinfo_attrs(mod, -1);
+ module_param_sysfs_remove(mod);
+ kobject_put(mod->mkobj.drivers_dir);
+ kobject_put(mod->holders_dir);
+ mod_sysfs_fini(mod);
+}
+
+void init_param_lock(struct module *mod)
+{
+ mutex_init(&mod->param_lock);
+}
--
2.34.1
No functional change.
This patch migrates code that allows one to generate a
list of loaded/or linked modules via /proc when procfs
support is enabled into kernel/module/procfs.c.
Reviewed-by: Christophe Leroy <[email protected]>
Signed-off-by: Aaron Tomlin <[email protected]>
---
kernel/module/Makefile | 1 +
kernel/module/internal.h | 1 +
kernel/module/main.c | 131 +-----------------------------------
kernel/module/procfs.c | 142 +++++++++++++++++++++++++++++++++++++++
4 files changed, 145 insertions(+), 130 deletions(-)
create mode 100644 kernel/module/procfs.c
diff --git a/kernel/module/Makefile b/kernel/module/Makefile
index 9901bed3ab5b..94296c98a67f 100644
--- a/kernel/module/Makefile
+++ b/kernel/module/Makefile
@@ -15,3 +15,4 @@ obj-$(CONFIG_MODULES_TREE_LOOKUP) += tree_lookup.o
obj-$(CONFIG_STRICT_MODULE_RWX) += strict_rwx.o
obj-$(CONFIG_DEBUG_KMEMLEAK) += debug_kmemleak.o
obj-$(CONFIG_KALLSYMS) += kallsyms.o
+obj-$(CONFIG_PROC_FS) += procfs.o
diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index 44ca05b9eb8f..6af40c2d145f 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -72,6 +72,7 @@ struct module *find_module_all(const char *name, size_t len, bool even_unformed)
int cmp_name(const void *name, const void *sym);
long module_get_offset(struct module *mod, unsigned int *size, Elf_Shdr *sechdr,
unsigned int section);
+char *module_flags(struct module *mod, char *buf);
static inline unsigned long kernel_symbol_value(const struct kernel_symbol *sym)
{
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 952079987ea4..44b6fd1acc44 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -22,7 +22,6 @@
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/elf.h>
-#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/syscalls.h>
#include <linux/fcntl.h>
@@ -805,31 +804,6 @@ SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
return ret;
}
-static inline void print_unload_info(struct seq_file *m, struct module *mod)
-{
- struct module_use *use;
- int printed_something = 0;
-
- seq_printf(m, " %i ", module_refcount(mod));
-
- /*
- * Always include a trailing , so userspace can differentiate
- * between this and the old multi-field proc format.
- */
- list_for_each_entry(use, &mod->source_list, source_list) {
- printed_something = 1;
- seq_printf(m, "%s,", use->source->name);
- }
-
- if (mod->init != NULL && mod->exit == NULL) {
- printed_something = 1;
- seq_puts(m, "[permanent],");
- }
-
- if (!printed_something)
- seq_puts(m, "-");
-}
-
void __symbol_put(const char *symbol)
{
struct find_symbol_arg fsa = {
@@ -919,12 +893,6 @@ void module_put(struct module *module)
EXPORT_SYMBOL(module_put);
#else /* !CONFIG_MODULE_UNLOAD */
-static inline void print_unload_info(struct seq_file *m, struct module *mod)
-{
- /* We don't know the usage count, or what modules are using. */
- seq_puts(m, " - -");
-}
-
static inline void module_unload_free(struct module *mod)
{
}
@@ -3596,7 +3564,7 @@ static void cfi_cleanup(struct module *mod)
}
/* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
-static char *module_flags(struct module *mod, char *buf)
+char *module_flags(struct module *mod, char *buf)
{
int bx = 0;
@@ -3619,103 +3587,6 @@ static char *module_flags(struct module *mod, char *buf)
return buf;
}
-#ifdef CONFIG_PROC_FS
-/* Called by the /proc file system to return a list of modules. */
-static void *m_start(struct seq_file *m, loff_t *pos)
-{
- mutex_lock(&module_mutex);
- return seq_list_start(&modules, *pos);
-}
-
-static void *m_next(struct seq_file *m, void *p, loff_t *pos)
-{
- return seq_list_next(p, &modules, pos);
-}
-
-static void m_stop(struct seq_file *m, void *p)
-{
- mutex_unlock(&module_mutex);
-}
-
-static int m_show(struct seq_file *m, void *p)
-{
- struct module *mod = list_entry(p, struct module, list);
- char buf[MODULE_FLAGS_BUF_SIZE];
- void *value;
-
- /* We always ignore unformed modules. */
- if (mod->state == MODULE_STATE_UNFORMED)
- return 0;
-
- seq_printf(m, "%s %u",
- mod->name, mod->init_layout.size + mod->core_layout.size);
- print_unload_info(m, mod);
-
- /* Informative for users. */
- seq_printf(m, " %s",
- mod->state == MODULE_STATE_GOING ? "Unloading" :
- mod->state == MODULE_STATE_COMING ? "Loading" :
- "Live");
- /* Used by oprofile and other similar tools. */
- value = m->private ? NULL : mod->core_layout.base;
- seq_printf(m, " 0x%px", value);
-
- /* Taints info */
- if (mod->taints)
- seq_printf(m, " %s", module_flags(mod, buf));
-
- seq_puts(m, "\n");
- return 0;
-}
-
-/*
- * Format: modulename size refcount deps address
- *
- * Where refcount is a number or -, and deps is a comma-separated list
- * of depends or -.
- */
-static const struct seq_operations modules_op = {
- .start = m_start,
- .next = m_next,
- .stop = m_stop,
- .show = m_show
-};
-
-/*
- * This also sets the "private" pointer to non-NULL if the
- * kernel pointers should be hidden (so you can just test
- * "m->private" to see if you should keep the values private).
- *
- * We use the same logic as for /proc/kallsyms.
- */
-static int modules_open(struct inode *inode, struct file *file)
-{
- int err = seq_open(file, &modules_op);
-
- if (!err) {
- struct seq_file *m = file->private_data;
- m->private = kallsyms_show_value(file->f_cred) ? NULL : (void *)8ul;
- }
-
- return err;
-}
-
-static const struct proc_ops modules_proc_ops = {
- .proc_flags = PROC_ENTRY_PERMANENT,
- .proc_open = modules_open,
- .proc_read = seq_read,
- .proc_lseek = seq_lseek,
- .proc_release = seq_release,
-};
-
-static int __init proc_modules_init(void)
-{
- proc_create("modules", 0, NULL, &modules_proc_ops);
- return 0;
-}
-module_init(proc_modules_init);
-#endif
-
/* Given an address, look for it in the module exception tables. */
const struct exception_table_entry *search_module_extables(unsigned long addr)
{
diff --git a/kernel/module/procfs.c b/kernel/module/procfs.c
new file mode 100644
index 000000000000..2717e130788e
--- /dev/null
+++ b/kernel/module/procfs.c
@@ -0,0 +1,142 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Module proc support
+ *
+ * Copyright (C) 2008 Alexey Dobriyan
+ */
+
+#include <linux/module.h>
+#include <linux/kallsyms.h>
+#include <linux/mutex.h>
+#include <linux/seq_file.h>
+#include <linux/proc_fs.h>
+#include "internal.h"
+
+#ifdef CONFIG_MODULE_UNLOAD
+static inline void print_unload_info(struct seq_file *m, struct module *mod)
+{
+ struct module_use *use;
+ int printed_something = 0;
+
+ seq_printf(m, " %i ", module_refcount(mod));
+
+ /*
+ * Always include a trailing , so userspace can differentiate
+ * between this and the old multi-field proc format.
+ */
+ list_for_each_entry(use, &mod->source_list, source_list) {
+ printed_something = 1;
+ seq_printf(m, "%s,", use->source->name);
+ }
+
+ if (mod->init && !mod->exit) {
+ printed_something = 1;
+ seq_puts(m, "[permanent],");
+ }
+
+ if (!printed_something)
+ seq_puts(m, "-");
+}
+#else /* !CONFIG_MODULE_UNLOAD */
+static inline void print_unload_info(struct seq_file *m, struct module *mod)
+{
+ /* We don't know the usage count, or what modules are using. */
+ seq_puts(m, " - -");
+}
+#endif /* CONFIG_MODULE_UNLOAD */
+
+/* Called by the /proc file system to return a list of modules. */
+static void *m_start(struct seq_file *m, loff_t *pos)
+{
+ mutex_lock(&module_mutex);
+ return seq_list_start(&modules, *pos);
+}
+
+static void *m_next(struct seq_file *m, void *p, loff_t *pos)
+{
+ return seq_list_next(p, &modules, pos);
+}
+
+static void m_stop(struct seq_file *m, void *p)
+{
+ mutex_unlock(&module_mutex);
+}
+
+static int m_show(struct seq_file *m, void *p)
+{
+ struct module *mod = list_entry(p, struct module, list);
+ char buf[MODULE_FLAGS_BUF_SIZE];
+ void *value;
+
+ /* We always ignore unformed modules. */
+ if (mod->state == MODULE_STATE_UNFORMED)
+ return 0;
+
+ seq_printf(m, "%s %u",
+ mod->name, mod->init_layout.size + mod->core_layout.size);
+ print_unload_info(m, mod);
+
+ /* Informative for users. */
+ seq_printf(m, " %s",
+ mod->state == MODULE_STATE_GOING ? "Unloading" :
+ mod->state == MODULE_STATE_COMING ? "Loading" :
+ "Live");
+ /* Used by oprofile and other similar tools. */
+ value = m->private ? NULL : mod->core_layout.base;
+ seq_printf(m, " 0x%px", value);
+
+ /* Taints info */
+ if (mod->taints)
+ seq_printf(m, " %s", module_flags(mod, buf));
+
+ seq_puts(m, "\n");
+ return 0;
+}
+
+/*
+ * Format: modulename size refcount deps address
+ *
+ * Where refcount is a number or -, and deps is a comma-separated list
+ * of depends or -.
+ */
+static const struct seq_operations modules_op = {
+ .start = m_start,
+ .next = m_next,
+ .stop = m_stop,
+ .show = m_show
+};
+
+/*
+ * This also sets the "private" pointer to non-NULL if the
+ * kernel pointers should be hidden (so you can just test
+ * "m->private" to see if you should keep the values private).
+ *
+ * We use the same logic as for /proc/kallsyms.
+ */
+static int modules_open(struct inode *inode, struct file *file)
+{
+ int err = seq_open(file, &modules_op);
+
+ if (!err) {
+ struct seq_file *m = file->private_data;
+
+ m->private = kallsyms_show_value(file->f_cred) ? NULL : (void *)8ul;
+ }
+
+ return err;
+}
+
+static const struct proc_ops modules_proc_ops = {
+ .proc_flags = PROC_ENTRY_PERMANENT,
+ .proc_open = modules_open,
+ .proc_read = seq_read,
+ .proc_lseek = seq_lseek,
+ .proc_release = seq_release,
+};
+
+static int __init proc_modules_init(void)
+{
+ proc_create("modules", 0, NULL, &modules_proc_ops);
+ return 0;
+}
+module_init(proc_modules_init);
--
2.34.1
No functional change.
The purpose of this patch is to address the various Sparse warnings
due to the incorrect dereference/or access of an __rcu pointer.
Signed-off-by: Aaron Tomlin <[email protected]>
---
kernel/module/kallsyms.c | 34 ++++++++++++++++++++++------------
1 file changed, 22 insertions(+), 12 deletions(-)
diff --git a/kernel/module/kallsyms.c b/kernel/module/kallsyms.c
index 1b0780e20aab..a3da0686a2a6 100644
--- a/kernel/module/kallsyms.c
+++ b/kernel/module/kallsyms.c
@@ -171,14 +171,17 @@ void add_kallsyms(struct module *mod, const struct load_info *info)
Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
/* Set up to point into init section. */
- mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
+ mod->kallsyms = (void __rcu *)mod->init_layout.base +
+ info->mod_kallsyms_init_off;
+ preempt_disable();
/* The following is safe since this pointer cannot change */
- mod->kallsyms->symtab = (void *)symsec->sh_addr;
- mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
+ rcu_dereference_sched(mod->kallsyms)->symtab = (void *)symsec->sh_addr;
+ rcu_dereference_sched(mod->kallsyms)->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
/* Make sure we get permanent strtab: don't use info->strtab. */
- mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
- mod->kallsyms->typetab = mod->init_layout.base + info->init_typeoffs;
+ rcu_dereference_sched(mod->kallsyms)->strtab =
+ (void *)info->sechdrs[info->index.str].sh_addr;
+ rcu_dereference_sched(mod->kallsyms)->typetab = mod->init_layout.base + info->init_typeoffs;
/*
* Now populate the cut down core kallsyms for after init
@@ -187,20 +190,22 @@ void add_kallsyms(struct module *mod, const struct load_info *info)
mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
mod->core_kallsyms.typetab = mod->core_layout.base + info->core_typeoffs;
- src = mod->kallsyms->symtab;
- for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
- mod->kallsyms->typetab[i] = elf_type(src + i, info);
+ src = rcu_dereference_sched(mod->kallsyms)->symtab;
+ for (ndst = i = 0; i < rcu_dereference_sched(mod->kallsyms)->num_symtab; i++) {
+ rcu_dereference_sched(mod->kallsyms)->typetab[i] = elf_type(src + i, info);
if (i == 0 || is_livepatch_module(mod) ||
is_core_symbol(src + i, info->sechdrs, info->hdr->e_shnum,
info->index.pcpu)) {
mod->core_kallsyms.typetab[ndst] =
- mod->kallsyms->typetab[i];
+ rcu_dereference_sched(mod->kallsyms)->typetab[i];
dst[ndst] = src[i];
dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
- s += strscpy(s, &mod->kallsyms->strtab[src[i].st_name],
+ s += strscpy(s,
+ &rcu_dereference_sched(mod->kallsyms)->strtab[src[i].st_name],
KSYM_NAME_LEN) + 1;
}
}
+ preempt_enable();
mod->core_kallsyms.num_symtab = ndst;
}
@@ -478,11 +483,16 @@ int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
mutex_lock(&module_mutex);
list_for_each_entry(mod, &modules, list) {
- /* We hold module_mutex: no need for rcu_dereference_sched */
- struct mod_kallsyms *kallsyms = mod->kallsyms;
+ struct mod_kallsyms *kallsyms;
if (mod->state == MODULE_STATE_UNFORMED)
continue;
+
+ /* Use rcu_dereference_sched() to remain compliant with the sparse tool */
+ preempt_disable();
+ kallsyms = rcu_dereference_sched(mod->kallsyms);
+ preempt_enable();
+
for (i = 0; i < kallsyms->num_symtab; i++) {
const Elf_Sym *sym = &kallsyms->symtab[i];
--
2.34.1
On Mon, Mar 07, 2022 at 05:44:55PM +0000, Aaron Tomlin wrote:
> Hi Luis,
>
> As per your suggestion [1], this is an attempt to refactor and split
> optional code out of core module support code into separate components.
> This version is based on Linus' commit 7993e65fdd0f ("Merge tag
> 'mtd/fixes-for-5.17-rc5' of
> git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux").
Thanks! Pushed out to modules-testing to see what 0-day can find.
Further review from others is welcomed in the meantime. If no issues
are found, we also get kmod testing done, and more reviews, I can
push then later to modules-next for further testing on linux-next.
Luis
This patch will address the following warning and style violations
generated by ./scripts/checkpatch.pl in strict mode:
WARNING: Use #include <linux/module.h> instead of <asm/module.h>
#10: FILE: kernel/module/internal.h:10:
+#include <asm/module.h>
CHECK: spaces preferred around that '-' (ctx:VxV)
#18: FILE: kernel/module/internal.h:18:
+#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
CHECK: Please use a blank line after function/struct/union/enum declarations
#69: FILE: kernel/module/internal.h:69:
+}
+static inline void module_decompress_cleanup(struct load_info *info)
^
CHECK: extern prototypes should be avoided in .h files
#84: FILE: kernel/module/internal.h:84:
+extern int mod_verify_sig(const void *mod, struct load_info *info);
WARNING: Missing a blank line after declarations
#116: FILE: kernel/module/decompress.c:116:
+ struct page *page = module_get_next_page(info);
+ if (!page) {
WARNING: Missing a blank line after declarations
#174: FILE: kernel/module/decompress.c:174:
+ struct page *page = module_get_next_page(info);
+ if (!page) {
CHECK: Please use a blank line after function/struct/union/enum declarations
#258: FILE: kernel/module/decompress.c:258:
+}
+static struct kobj_attribute module_compression_attr = __ATTR_RO(compression);
Note: Fortunately, the multiple-include optimisation found in
include/linux/module.h will prevent duplication/or inclusion more than
once.
Fixes: f314dfea16a ("modsign: log module name in the event of an error")
Reviewed-by: Christophe Leroy <[email protected]>
Signed-off-by: Aaron Tomlin <[email protected]>
---
kernel/module/decompress.c | 3 +++
kernel/module/internal.h | 6 ++++--
2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/kernel/module/decompress.c b/kernel/module/decompress.c
index d14d6443225a..2fc7081dd7c1 100644
--- a/kernel/module/decompress.c
+++ b/kernel/module/decompress.c
@@ -113,6 +113,7 @@ static ssize_t module_gzip_decompress(struct load_info *info,
do {
struct page *page = module_get_next_page(info);
+
if (!page) {
retval = -ENOMEM;
goto out_inflate_end;
@@ -171,6 +172,7 @@ static ssize_t module_xz_decompress(struct load_info *info,
do {
struct page *page = module_get_next_page(info);
+
if (!page) {
retval = -ENOMEM;
goto out;
@@ -256,6 +258,7 @@ static ssize_t compression_show(struct kobject *kobj,
{
return sysfs_emit(buf, "%s\n", __stringify(MODULE_COMPRESSION));
}
+
static struct kobj_attribute module_compression_attr = __ATTR_RO(compression);
static int __init module_decompress_sysfs_init(void)
diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index ea8c4c02614c..e0775e66bcf7 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -6,7 +6,8 @@
*/
#include <linux/elf.h>
-#include <asm/module.h>
+#include <linux/compiler.h>
+#include <linux/module.h>
#include <linux/mutex.h>
#ifndef ARCH_SHF_SMALL
@@ -54,7 +55,7 @@ struct load_info {
} index;
};
-extern int mod_verify_sig(const void *mod, struct load_info *info);
+int mod_verify_sig(const void *mod, struct load_info *info);
#ifdef CONFIG_MODULE_DECOMPRESS
int module_decompress(struct load_info *info, const void *buf, size_t size);
@@ -65,6 +66,7 @@ static inline int module_decompress(struct load_info *info,
{
return -EOPNOTSUPP;
}
+
static inline void module_decompress_cleanup(struct load_info *info)
{
}
--
2.34.1
No functional change.
This patch migrates livepatch support (i.e. used during module
add/or load and remove/or deletion) from core module code into
kernel/module/livepatch.c. At the moment it contains code to
persist Elf information about a given livepatch module, only.
The new file was added to MAINTAINERS.
Reviewed-by: Petr Mladek <[email protected]>
Tested-by: Petr Mladek <[email protected]>
Signed-off-by: Aaron Tomlin <[email protected]>
---
MAINTAINERS | 1 +
include/linux/module.h | 9 ++--
kernel/module/Makefile | 1 +
kernel/module/internal.h | 22 ++++++++
kernel/module/livepatch.c | 74 +++++++++++++++++++++++++++
kernel/module/main.c | 102 ++++----------------------------------
6 files changed, 111 insertions(+), 98 deletions(-)
create mode 100644 kernel/module/livepatch.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 463bdb829db4..195cf1ac2ee8 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -11149,6 +11149,7 @@ F: arch/s390/include/asm/livepatch.h
F: arch/x86/include/asm/livepatch.h
F: include/linux/livepatch.h
F: kernel/livepatch/
+F: kernel/module/livepatch.c
F: lib/livepatch/
F: samples/livepatch/
F: tools/testing/selftests/livepatch/
diff --git a/include/linux/module.h b/include/linux/module.h
index 1e135fd5c076..7ec9715de7dc 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -663,17 +663,14 @@ static inline bool module_requested_async_probing(struct module *module)
return module && module->async_probe_requested;
}
-#ifdef CONFIG_LIVEPATCH
static inline bool is_livepatch_module(struct module *mod)
{
+#ifdef CONFIG_LIVEPATCH
return mod->klp;
-}
-#else /* !CONFIG_LIVEPATCH */
-static inline bool is_livepatch_module(struct module *mod)
-{
+#else
return false;
+#endif
}
-#endif /* CONFIG_LIVEPATCH */
bool is_module_sig_enforced(void);
void set_module_sig_enforced(void);
diff --git a/kernel/module/Makefile b/kernel/module/Makefile
index cdd5c61b8c7f..ed3aacb04f17 100644
--- a/kernel/module/Makefile
+++ b/kernel/module/Makefile
@@ -10,3 +10,4 @@ KCOV_INSTRUMENT_module.o := n
obj-y += main.o
obj-$(CONFIG_MODULE_DECOMPRESS) += decompress.o
obj-$(CONFIG_MODULE_SIG) += signing.o
+obj-$(CONFIG_LIVEPATCH) += livepatch.o
diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index e0775e66bcf7..ad7a444253ed 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -57,6 +57,28 @@ struct load_info {
int mod_verify_sig(const void *mod, struct load_info *info);
+#ifdef CONFIG_LIVEPATCH
+int copy_module_elf(struct module *mod, struct load_info *info);
+void free_module_elf(struct module *mod);
+#else /* !CONFIG_LIVEPATCH */
+static inline int copy_module_elf(struct module *mod, struct load_info *info)
+{
+ return 0;
+}
+
+static inline void free_module_elf(struct module *mod) { }
+#endif /* CONFIG_LIVEPATCH */
+
+static inline bool set_livepatch_module(struct module *mod)
+{
+#ifdef CONFIG_LIVEPATCH
+ mod->klp = true;
+ return true;
+#else
+ return false;
+#endif
+}
+
#ifdef CONFIG_MODULE_DECOMPRESS
int module_decompress(struct load_info *info, const void *buf, size_t size);
void module_decompress_cleanup(struct load_info *info);
diff --git a/kernel/module/livepatch.c b/kernel/module/livepatch.c
new file mode 100644
index 000000000000..486d4ff92719
--- /dev/null
+++ b/kernel/module/livepatch.c
@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Module livepatch support
+ *
+ * Copyright (C) 2016 Jessica Yu <[email protected]>
+ */
+
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include "internal.h"
+
+/*
+ * Persist Elf information about a module. Copy the Elf header,
+ * section header table, section string table, and symtab section
+ * index from info to mod->klp_info.
+ */
+int copy_module_elf(struct module *mod, struct load_info *info)
+{
+ unsigned int size, symndx;
+ int ret;
+
+ size = sizeof(*mod->klp_info);
+ mod->klp_info = kmalloc(size, GFP_KERNEL);
+ if (!mod->klp_info)
+ return -ENOMEM;
+
+ /* Elf header */
+ size = sizeof(mod->klp_info->hdr);
+ memcpy(&mod->klp_info->hdr, info->hdr, size);
+
+ /* Elf section header table */
+ size = sizeof(*info->sechdrs) * info->hdr->e_shnum;
+ mod->klp_info->sechdrs = kmemdup(info->sechdrs, size, GFP_KERNEL);
+ if (!mod->klp_info->sechdrs) {
+ ret = -ENOMEM;
+ goto free_info;
+ }
+
+ /* Elf section name string table */
+ size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
+ mod->klp_info->secstrings = kmemdup(info->secstrings, size, GFP_KERNEL);
+ if (!mod->klp_info->secstrings) {
+ ret = -ENOMEM;
+ goto free_sechdrs;
+ }
+
+ /* Elf symbol section index */
+ symndx = info->index.sym;
+ mod->klp_info->symndx = symndx;
+
+ /*
+ * For livepatch modules, core_kallsyms.symtab is a complete
+ * copy of the original symbol table. Adjust sh_addr to point
+ * to core_kallsyms.symtab since the copy of the symtab in module
+ * init memory is freed at the end of do_init_module().
+ */
+ mod->klp_info->sechdrs[symndx].sh_addr = (unsigned long)mod->core_kallsyms.symtab;
+
+ return 0;
+
+free_sechdrs:
+ kfree(mod->klp_info->sechdrs);
+free_info:
+ kfree(mod->klp_info);
+ return ret;
+}
+
+void free_module_elf(struct module *mod)
+{
+ kfree(mod->klp_info->sechdrs);
+ kfree(mod->klp_info->secstrings);
+ kfree(mod->klp_info);
+}
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 5f5e21f972dd..3596ebf3a6c3 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -2043,81 +2043,6 @@ static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
}
#endif /* CONFIG_STRICT_MODULE_RWX */
-#ifdef CONFIG_LIVEPATCH
-/*
- * Persist Elf information about a module. Copy the Elf header,
- * section header table, section string table, and symtab section
- * index from info to mod->klp_info.
- */
-static int copy_module_elf(struct module *mod, struct load_info *info)
-{
- unsigned int size, symndx;
- int ret;
-
- size = sizeof(*mod->klp_info);
- mod->klp_info = kmalloc(size, GFP_KERNEL);
- if (mod->klp_info == NULL)
- return -ENOMEM;
-
- /* Elf header */
- size = sizeof(mod->klp_info->hdr);
- memcpy(&mod->klp_info->hdr, info->hdr, size);
-
- /* Elf section header table */
- size = sizeof(*info->sechdrs) * info->hdr->e_shnum;
- mod->klp_info->sechdrs = kmemdup(info->sechdrs, size, GFP_KERNEL);
- if (mod->klp_info->sechdrs == NULL) {
- ret = -ENOMEM;
- goto free_info;
- }
-
- /* Elf section name string table */
- size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
- mod->klp_info->secstrings = kmemdup(info->secstrings, size, GFP_KERNEL);
- if (mod->klp_info->secstrings == NULL) {
- ret = -ENOMEM;
- goto free_sechdrs;
- }
-
- /* Elf symbol section index */
- symndx = info->index.sym;
- mod->klp_info->symndx = symndx;
-
- /*
- * For livepatch modules, core_kallsyms.symtab is a complete
- * copy of the original symbol table. Adjust sh_addr to point
- * to core_kallsyms.symtab since the copy of the symtab in module
- * init memory is freed at the end of do_init_module().
- */
- mod->klp_info->sechdrs[symndx].sh_addr = \
- (unsigned long) mod->core_kallsyms.symtab;
-
- return 0;
-
-free_sechdrs:
- kfree(mod->klp_info->sechdrs);
-free_info:
- kfree(mod->klp_info);
- return ret;
-}
-
-static void free_module_elf(struct module *mod)
-{
- kfree(mod->klp_info->sechdrs);
- kfree(mod->klp_info->secstrings);
- kfree(mod->klp_info);
-}
-#else /* !CONFIG_LIVEPATCH */
-static int copy_module_elf(struct module *mod, struct load_info *info)
-{
- return 0;
-}
-
-static void free_module_elf(struct module *mod)
-{
-}
-#endif /* CONFIG_LIVEPATCH */
-
void __weak module_memfree(void *module_region)
{
/*
@@ -3092,30 +3017,23 @@ static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned l
return 0;
}
-#ifdef CONFIG_LIVEPATCH
static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
{
- if (get_modinfo(info, "livepatch")) {
- mod->klp = true;
+ if (!get_modinfo(info, "livepatch"))
+ /* Nothing more to do */
+ return 0;
+
+ if (set_livepatch_module(mod)) {
add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK);
pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
- mod->name);
- }
-
- return 0;
-}
-#else /* !CONFIG_LIVEPATCH */
-static int check_modinfo_livepatch(struct module *mod, struct load_info *info)
-{
- if (get_modinfo(info, "livepatch")) {
- pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
- mod->name);
- return -ENOEXEC;
+ mod->name);
+ return 0;
}
- return 0;
+ pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
+ mod->name);
+ return -ENOEXEC;
}
-#endif /* CONFIG_LIVEPATCH */
static void check_modinfo_retpoline(struct module *mod, struct load_info *info)
{
--
2.34.1
No functional change.
This patch migrates additional module signature check
code from core module code into kernel/module/signing.c.
Reviewed-by: Christophe Leroy <[email protected]>
Signed-off-by: Aaron Tomlin <[email protected]>
---
include/linux/module.h | 12 +++---
kernel/module/internal.h | 9 +++++
kernel/module/main.c | 87 ----------------------------------------
kernel/module/signing.c | 77 +++++++++++++++++++++++++++++++++++
4 files changed, 93 insertions(+), 92 deletions(-)
diff --git a/include/linux/module.h b/include/linux/module.h
index 7ec9715de7dc..5e2059f3afc7 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -672,7 +672,6 @@ static inline bool is_livepatch_module(struct module *mod)
#endif
}
-bool is_module_sig_enforced(void);
void set_module_sig_enforced(void);
#else /* !CONFIG_MODULES... */
@@ -799,10 +798,6 @@ static inline bool module_requested_async_probing(struct module *module)
return false;
}
-static inline bool is_module_sig_enforced(void)
-{
- return false;
-}
static inline void set_module_sig_enforced(void)
{
@@ -854,11 +849,18 @@ static inline bool retpoline_module_ok(bool has_retpoline)
#endif
#ifdef CONFIG_MODULE_SIG
+bool is_module_sig_enforced(void);
+
static inline bool module_sig_ok(struct module *module)
{
return module->sig_ok;
}
#else /* !CONFIG_MODULE_SIG */
+static inline bool is_module_sig_enforced(void)
+{
+ return false;
+}
+
static inline bool module_sig_ok(struct module *module)
{
return true;
diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index a6895bb5598a..d6f646a5da41 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -158,3 +158,12 @@ static inline int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
return 0;
}
#endif /* CONFIG_STRICT_MODULE_RWX */
+
+#ifdef CONFIG_MODULE_SIG
+int module_sig_check(struct load_info *info, int flags);
+#else /* !CONFIG_MODULE_SIG */
+static inline int module_sig_check(struct load_info *info, int flags)
+{
+ return 0;
+}
+#endif /* !CONFIG_MODULE_SIG */
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 5cd63f14b1ef..c63e10c61694 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -23,7 +23,6 @@
#include <linux/vmalloc.h>
#include <linux/elf.h>
#include <linux/proc_fs.h>
-#include <linux/security.h>
#include <linux/seq_file.h>
#include <linux/syscalls.h>
#include <linux/fcntl.h>
@@ -127,28 +126,6 @@ static void module_assert_mutex_or_preempt(void)
#endif
}
-#ifdef CONFIG_MODULE_SIG
-static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
-module_param(sig_enforce, bool_enable_only, 0644);
-
-void set_module_sig_enforced(void)
-{
- sig_enforce = true;
-}
-#else
-#define sig_enforce false
-#endif
-
-/*
- * Export sig_enforce kernel cmdline parameter to allow other subsystems rely
- * on that instead of directly to CONFIG_MODULE_SIG_FORCE config.
- */
-bool is_module_sig_enforced(void)
-{
- return sig_enforce;
-}
-EXPORT_SYMBOL(is_module_sig_enforced);
-
/* Block module loading/unloading? */
int modules_disabled = 0;
core_param(nomodule, modules_disabled, bint, 0);
@@ -2569,70 +2546,6 @@ static inline void kmemleak_load_module(const struct module *mod,
}
#endif
-#ifdef CONFIG_MODULE_SIG
-static int module_sig_check(struct load_info *info, int flags)
-{
- int err = -ENODATA;
- const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
- const char *reason;
- const void *mod = info->hdr;
- bool mangled_module = flags & (MODULE_INIT_IGNORE_MODVERSIONS |
- MODULE_INIT_IGNORE_VERMAGIC);
- /*
- * Do not allow mangled modules as a module with version information
- * removed is no longer the module that was signed.
- */
- if (!mangled_module &&
- info->len > markerlen &&
- memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
- /* We truncate the module to discard the signature */
- info->len -= markerlen;
- err = mod_verify_sig(mod, info);
- if (!err) {
- info->sig_ok = true;
- return 0;
- }
- }
-
- /*
- * We don't permit modules to be loaded into the trusted kernels
- * without a valid signature on them, but if we're not enforcing,
- * certain errors are non-fatal.
- */
- switch (err) {
- case -ENODATA:
- reason = "unsigned module";
- break;
- case -ENOPKG:
- reason = "module with unsupported crypto";
- break;
- case -ENOKEY:
- reason = "module with unavailable key";
- break;
-
- default:
- /*
- * All other errors are fatal, including lack of memory,
- * unparseable signatures, and signature check failures --
- * even if signatures aren't required.
- */
- return err;
- }
-
- if (is_module_sig_enforced()) {
- pr_notice("Loading of %s is rejected\n", reason);
- return -EKEYREJECTED;
- }
-
- return security_locked_down(LOCKDOWN_MODULE_SIGNATURE);
-}
-#else /* !CONFIG_MODULE_SIG */
-static int module_sig_check(struct load_info *info, int flags)
-{
- return 0;
-}
-#endif /* !CONFIG_MODULE_SIG */
-
static int validate_section_offset(struct load_info *info, Elf_Shdr *shdr)
{
#if defined(CONFIG_64BIT)
diff --git a/kernel/module/signing.c b/kernel/module/signing.c
index 8aeb6d2ee94b..85c8999dfecf 100644
--- a/kernel/module/signing.c
+++ b/kernel/module/signing.c
@@ -11,9 +11,29 @@
#include <linux/module_signature.h>
#include <linux/string.h>
#include <linux/verification.h>
+#include <linux/security.h>
#include <crypto/public_key.h>
+#include <uapi/linux/module.h>
#include "internal.h"
+static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
+module_param(sig_enforce, bool_enable_only, 0644);
+
+/*
+ * Export sig_enforce kernel cmdline parameter to allow other subsystems rely
+ * on that instead of directly to CONFIG_MODULE_SIG_FORCE config.
+ */
+bool is_module_sig_enforced(void)
+{
+ return sig_enforce;
+}
+EXPORT_SYMBOL(is_module_sig_enforced);
+
+void set_module_sig_enforced(void)
+{
+ sig_enforce = true;
+}
+
/*
* Verify the signature on a module.
*/
@@ -43,3 +63,60 @@ int mod_verify_sig(const void *mod, struct load_info *info)
VERIFYING_MODULE_SIGNATURE,
NULL, NULL);
}
+
+int module_sig_check(struct load_info *info, int flags)
+{
+ int err = -ENODATA;
+ const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
+ const char *reason;
+ const void *mod = info->hdr;
+ bool mangled_module = flags & (MODULE_INIT_IGNORE_MODVERSIONS |
+ MODULE_INIT_IGNORE_VERMAGIC);
+ /*
+ * Do not allow mangled modules as a module with version information
+ * removed is no longer the module that was signed.
+ */
+ if (!mangled_module &&
+ info->len > markerlen &&
+ memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
+ /* We truncate the module to discard the signature */
+ info->len -= markerlen;
+ err = mod_verify_sig(mod, info);
+ if (!err) {
+ info->sig_ok = true;
+ return 0;
+ }
+ }
+
+ /*
+ * We don't permit modules to be loaded into the trusted kernels
+ * without a valid signature on them, but if we're not enforcing,
+ * certain errors are non-fatal.
+ */
+ switch (err) {
+ case -ENODATA:
+ reason = "unsigned module";
+ break;
+ case -ENOPKG:
+ reason = "module with unsupported crypto";
+ break;
+ case -ENOKEY:
+ reason = "module with unavailable key";
+ break;
+
+ default:
+ /*
+ * All other errors are fatal, including lack of memory,
+ * unparseable signatures, and signature check failures --
+ * even if signatures aren't required.
+ */
+ return err;
+ }
+
+ if (is_module_sig_enforced()) {
+ pr_notice("Loading of %s is rejected\n", reason);
+ return -EKEYREJECTED;
+ }
+
+ return security_locked_down(LOCKDOWN_MODULE_SIGNATURE);
+}
--
2.34.1
No functional change.
This patch migrates kallsyms code out of core module
code kernel/module/kallsyms.c
Signed-off-by: Aaron Tomlin <[email protected]>
---
kernel/module/Makefile | 1 +
kernel/module/internal.h | 29 +++
kernel/module/kallsyms.c | 502 ++++++++++++++++++++++++++++++++++++
kernel/module/main.c | 531 +--------------------------------------
4 files changed, 538 insertions(+), 525 deletions(-)
create mode 100644 kernel/module/kallsyms.c
diff --git a/kernel/module/Makefile b/kernel/module/Makefile
index 12388627725c..9901bed3ab5b 100644
--- a/kernel/module/Makefile
+++ b/kernel/module/Makefile
@@ -14,3 +14,4 @@ obj-$(CONFIG_LIVEPATCH) += livepatch.o
obj-$(CONFIG_MODULES_TREE_LOOKUP) += tree_lookup.o
obj-$(CONFIG_STRICT_MODULE_RWX) += strict_rwx.o
obj-$(CONFIG_DEBUG_KMEMLEAK) += debug_kmemleak.o
+obj-$(CONFIG_KALLSYMS) += kallsyms.o
diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index b0c360839f63..44ca05b9eb8f 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -68,6 +68,19 @@ struct load_info {
};
int mod_verify_sig(const void *mod, struct load_info *info);
+struct module *find_module_all(const char *name, size_t len, bool even_unformed);
+int cmp_name(const void *name, const void *sym);
+long module_get_offset(struct module *mod, unsigned int *size, Elf_Shdr *sechdr,
+ unsigned int section);
+
+static inline unsigned long kernel_symbol_value(const struct kernel_symbol *sym)
+{
+#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
+ return (unsigned long)offset_to_ptr(&sym->value_offset);
+#else
+ return sym->value;
+#endif
+}
#ifdef CONFIG_LIVEPATCH
int copy_module_elf(struct module *mod, struct load_info *info);
@@ -174,3 +187,19 @@ void kmemleak_load_module(const struct module *mod, const struct load_info *info
static inline void kmemleak_load_module(const struct module *mod,
const struct load_info *info) { }
#endif /* CONFIG_DEBUG_KMEMLEAK */
+
+#ifdef CONFIG_KALLSYMS
+void init_build_id(struct module *mod, const struct load_info *info);
+void layout_symtab(struct module *mod, struct load_info *info);
+void add_kallsyms(struct module *mod, const struct load_info *info);
+unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name);
+
+static inline bool sect_empty(const Elf_Shdr *sect)
+{
+ return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
+}
+#else /* !CONFIG_KALLSYMS */
+static inline void init_build_id(struct module *mod, const struct load_info *info) { }
+static inline void layout_symtab(struct module *mod, struct load_info *info) { }
+static inline void add_kallsyms(struct module *mod, const struct load_info *info) { }
+#endif /* CONFIG_KALLSYMS */
diff --git a/kernel/module/kallsyms.c b/kernel/module/kallsyms.c
new file mode 100644
index 000000000000..1b0780e20aab
--- /dev/null
+++ b/kernel/module/kallsyms.c
@@ -0,0 +1,502 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Module kallsyms support
+ *
+ * Copyright (C) 2010 Rusty Russell
+ */
+
+#include <linux/module.h>
+#include <linux/kallsyms.h>
+#include <linux/buildid.h>
+#include <linux/bsearch.h>
+#include "internal.h"
+
+/* Lookup exported symbol in given range of kernel_symbols */
+static const struct kernel_symbol *lookup_exported_symbol(const char *name,
+ const struct kernel_symbol *start,
+ const struct kernel_symbol *stop)
+{
+ return bsearch(name, start, stop - start,
+ sizeof(struct kernel_symbol), cmp_name);
+}
+
+static int is_exported(const char *name, unsigned long value,
+ const struct module *mod)
+{
+ const struct kernel_symbol *ks;
+
+ if (!mod)
+ ks = lookup_exported_symbol(name, __start___ksymtab, __stop___ksymtab);
+ else
+ ks = lookup_exported_symbol(name, mod->syms, mod->syms + mod->num_syms);
+
+ return ks && kernel_symbol_value(ks) == value;
+}
+
+/* As per nm */
+static char elf_type(const Elf_Sym *sym, const struct load_info *info)
+{
+ const Elf_Shdr *sechdrs = info->sechdrs;
+
+ if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
+ if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
+ return 'v';
+ else
+ return 'w';
+ }
+ if (sym->st_shndx == SHN_UNDEF)
+ return 'U';
+ if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
+ return 'a';
+ if (sym->st_shndx >= SHN_LORESERVE)
+ return '?';
+ if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
+ return 't';
+ if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC &&
+ sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
+ if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
+ return 'r';
+ else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
+ return 'g';
+ else
+ return 'd';
+ }
+ if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
+ if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
+ return 's';
+ else
+ return 'b';
+ }
+ if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
+ ".debug")) {
+ return 'n';
+ }
+ return '?';
+}
+
+static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
+ unsigned int shnum, unsigned int pcpundx)
+{
+ const Elf_Shdr *sec;
+
+ if (src->st_shndx == SHN_UNDEF ||
+ src->st_shndx >= shnum ||
+ !src->st_name)
+ return false;
+
+#ifdef CONFIG_KALLSYMS_ALL
+ if (src->st_shndx == pcpundx)
+ return true;
+#endif
+
+ sec = sechdrs + src->st_shndx;
+ if (!(sec->sh_flags & SHF_ALLOC)
+#ifndef CONFIG_KALLSYMS_ALL
+ || !(sec->sh_flags & SHF_EXECINSTR)
+#endif
+ || (sec->sh_entsize & INIT_OFFSET_MASK))
+ return false;
+
+ return true;
+}
+
+/*
+ * We only allocate and copy the strings needed by the parts of symtab
+ * we keep. This is simple, but has the effect of making multiple
+ * copies of duplicates. We could be more sophisticated, see
+ * linux-kernel thread starting with
+ * <73defb5e4bca04a6431392cc341112b1@localhost>.
+ */
+void layout_symtab(struct module *mod, struct load_info *info)
+{
+ Elf_Shdr *symsect = info->sechdrs + info->index.sym;
+ Elf_Shdr *strsect = info->sechdrs + info->index.str;
+ const Elf_Sym *src;
+ unsigned int i, nsrc, ndst, strtab_size = 0;
+
+ /* Put symbol section at end of init part of module. */
+ symsect->sh_flags |= SHF_ALLOC;
+ symsect->sh_entsize = module_get_offset(mod, &mod->init_layout.size, symsect,
+ info->index.sym) | INIT_OFFSET_MASK;
+ pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
+
+ src = (void *)info->hdr + symsect->sh_offset;
+ nsrc = symsect->sh_size / sizeof(*src);
+
+ /* Compute total space required for the core symbols' strtab. */
+ for (ndst = i = 0; i < nsrc; i++) {
+ if (i == 0 || is_livepatch_module(mod) ||
+ is_core_symbol(src + i, info->sechdrs, info->hdr->e_shnum,
+ info->index.pcpu)) {
+ strtab_size += strlen(&info->strtab[src[i].st_name]) + 1;
+ ndst++;
+ }
+ }
+
+ /* Append room for core symbols at end of core part. */
+ info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
+ info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
+ mod->core_layout.size += strtab_size;
+ info->core_typeoffs = mod->core_layout.size;
+ mod->core_layout.size += ndst * sizeof(char);
+ mod->core_layout.size = debug_align(mod->core_layout.size);
+
+ /* Put string table section at end of init part of module. */
+ strsect->sh_flags |= SHF_ALLOC;
+ strsect->sh_entsize = module_get_offset(mod, &mod->init_layout.size, strsect,
+ info->index.str) | INIT_OFFSET_MASK;
+ pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
+
+ /* We'll tack temporary mod_kallsyms on the end. */
+ mod->init_layout.size = ALIGN(mod->init_layout.size,
+ __alignof__(struct mod_kallsyms));
+ info->mod_kallsyms_init_off = mod->init_layout.size;
+ mod->init_layout.size += sizeof(struct mod_kallsyms);
+ info->init_typeoffs = mod->init_layout.size;
+ mod->init_layout.size += nsrc * sizeof(char);
+ mod->init_layout.size = debug_align(mod->init_layout.size);
+}
+
+/*
+ * We use the full symtab and strtab which layout_symtab arranged to
+ * be appended to the init section. Later we switch to the cut-down
+ * core-only ones.
+ */
+void add_kallsyms(struct module *mod, const struct load_info *info)
+{
+ unsigned int i, ndst;
+ const Elf_Sym *src;
+ Elf_Sym *dst;
+ char *s;
+ Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
+
+ /* Set up to point into init section. */
+ mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
+
+ /* The following is safe since this pointer cannot change */
+ mod->kallsyms->symtab = (void *)symsec->sh_addr;
+ mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
+ /* Make sure we get permanent strtab: don't use info->strtab. */
+ mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
+ mod->kallsyms->typetab = mod->init_layout.base + info->init_typeoffs;
+
+ /*
+ * Now populate the cut down core kallsyms for after init
+ * and set types up while we still have access to sections.
+ */
+ mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
+ mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
+ mod->core_kallsyms.typetab = mod->core_layout.base + info->core_typeoffs;
+ src = mod->kallsyms->symtab;
+ for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
+ mod->kallsyms->typetab[i] = elf_type(src + i, info);
+ if (i == 0 || is_livepatch_module(mod) ||
+ is_core_symbol(src + i, info->sechdrs, info->hdr->e_shnum,
+ info->index.pcpu)) {
+ mod->core_kallsyms.typetab[ndst] =
+ mod->kallsyms->typetab[i];
+ dst[ndst] = src[i];
+ dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
+ s += strscpy(s, &mod->kallsyms->strtab[src[i].st_name],
+ KSYM_NAME_LEN) + 1;
+ }
+ }
+ mod->core_kallsyms.num_symtab = ndst;
+}
+
+#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID)
+void init_build_id(struct module *mod, const struct load_info *info)
+{
+ const Elf_Shdr *sechdr;
+ unsigned int i;
+
+ for (i = 0; i < info->hdr->e_shnum; i++) {
+ sechdr = &info->sechdrs[i];
+ if (!sect_empty(sechdr) && sechdr->sh_type == SHT_NOTE &&
+ !build_id_parse_buf((void *)sechdr->sh_addr, mod->build_id,
+ sechdr->sh_size))
+ break;
+ }
+}
+#else
+void init_build_id(struct module *mod, const struct load_info *info)
+{
+}
+#endif
+
+/*
+ * This ignores the intensely annoying "mapping symbols" found
+ * in ARM ELF files: $a, $t and $d.
+ */
+static inline int is_arm_mapping_symbol(const char *str)
+{
+ if (str[0] == '.' && str[1] == 'L')
+ return true;
+ return str[0] == '$' && strchr("axtd", str[1]) &&
+ (str[2] == '\0' || str[2] == '.');
+}
+
+static const char *kallsyms_symbol_name(struct mod_kallsyms *kallsyms, unsigned int symnum)
+{
+ return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
+}
+
+/*
+ * Given a module and address, find the corresponding symbol and return its name
+ * while providing its size and offset if needed.
+ */
+static const char *find_kallsyms_symbol(struct module *mod,
+ unsigned long addr,
+ unsigned long *size,
+ unsigned long *offset)
+{
+ unsigned int i, best = 0;
+ unsigned long nextval, bestval;
+ struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
+
+ /* At worse, next value is at end of module */
+ if (within_module_init(addr, mod))
+ nextval = (unsigned long)mod->init_layout.base + mod->init_layout.text_size;
+ else
+ nextval = (unsigned long)mod->core_layout.base + mod->core_layout.text_size;
+
+ bestval = kallsyms_symbol_value(&kallsyms->symtab[best]);
+
+ /*
+ * Scan for closest preceding symbol, and next symbol. (ELF
+ * starts real symbols at 1).
+ */
+ for (i = 1; i < kallsyms->num_symtab; i++) {
+ const Elf_Sym *sym = &kallsyms->symtab[i];
+ unsigned long thisval = kallsyms_symbol_value(sym);
+
+ if (sym->st_shndx == SHN_UNDEF)
+ continue;
+
+ /*
+ * We ignore unnamed symbols: they're uninformative
+ * and inserted at a whim.
+ */
+ if (*kallsyms_symbol_name(kallsyms, i) == '\0' ||
+ is_arm_mapping_symbol(kallsyms_symbol_name(kallsyms, i)))
+ continue;
+
+ if (thisval <= addr && thisval > bestval) {
+ best = i;
+ bestval = thisval;
+ }
+ if (thisval > addr && thisval < nextval)
+ nextval = thisval;
+ }
+
+ if (!best)
+ return NULL;
+
+ if (size)
+ *size = nextval - bestval;
+ if (offset)
+ *offset = addr - bestval;
+
+ return kallsyms_symbol_name(kallsyms, best);
+}
+
+void * __weak dereference_module_function_descriptor(struct module *mod,
+ void *ptr)
+{
+ return ptr;
+}
+
+/*
+ * For kallsyms to ask for address resolution. NULL means not found. Careful
+ * not to lock to avoid deadlock on oopses, simply disable preemption.
+ */
+const char *module_address_lookup(unsigned long addr,
+ unsigned long *size,
+ unsigned long *offset,
+ char **modname,
+ const unsigned char **modbuildid,
+ char *namebuf)
+{
+ const char *ret = NULL;
+ struct module *mod;
+
+ preempt_disable();
+ mod = __module_address(addr);
+ if (mod) {
+ if (modname)
+ *modname = mod->name;
+ if (modbuildid) {
+#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID)
+ *modbuildid = mod->build_id;
+#else
+ *modbuildid = NULL;
+#endif
+ }
+
+ ret = find_kallsyms_symbol(mod, addr, size, offset);
+ }
+ /* Make a copy in here where it's safe */
+ if (ret) {
+ strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
+ ret = namebuf;
+ }
+ preempt_enable();
+
+ return ret;
+}
+
+int lookup_module_symbol_name(unsigned long addr, char *symname)
+{
+ struct module *mod;
+
+ preempt_disable();
+ list_for_each_entry_rcu(mod, &modules, list) {
+ if (mod->state == MODULE_STATE_UNFORMED)
+ continue;
+ if (within_module(addr, mod)) {
+ const char *sym;
+
+ sym = find_kallsyms_symbol(mod, addr, NULL, NULL);
+ if (!sym)
+ goto out;
+
+ strscpy(symname, sym, KSYM_NAME_LEN);
+ preempt_enable();
+ return 0;
+ }
+ }
+out:
+ preempt_enable();
+ return -ERANGE;
+}
+
+int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
+ unsigned long *offset, char *modname, char *name)
+{
+ struct module *mod;
+
+ preempt_disable();
+ list_for_each_entry_rcu(mod, &modules, list) {
+ if (mod->state == MODULE_STATE_UNFORMED)
+ continue;
+ if (within_module(addr, mod)) {
+ const char *sym;
+
+ sym = find_kallsyms_symbol(mod, addr, size, offset);
+ if (!sym)
+ goto out;
+ if (modname)
+ strscpy(modname, mod->name, MODULE_NAME_LEN);
+ if (name)
+ strscpy(name, sym, KSYM_NAME_LEN);
+ preempt_enable();
+ return 0;
+ }
+ }
+out:
+ preempt_enable();
+ return -ERANGE;
+}
+
+int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
+ char *name, char *module_name, int *exported)
+{
+ struct module *mod;
+
+ preempt_disable();
+ list_for_each_entry_rcu(mod, &modules, list) {
+ struct mod_kallsyms *kallsyms;
+
+ if (mod->state == MODULE_STATE_UNFORMED)
+ continue;
+ kallsyms = rcu_dereference_sched(mod->kallsyms);
+ if (symnum < kallsyms->num_symtab) {
+ const Elf_Sym *sym = &kallsyms->symtab[symnum];
+
+ *value = kallsyms_symbol_value(sym);
+ *type = kallsyms->typetab[symnum];
+ strscpy(name, kallsyms_symbol_name(kallsyms, symnum), KSYM_NAME_LEN);
+ strscpy(module_name, mod->name, MODULE_NAME_LEN);
+ *exported = is_exported(name, *value, mod);
+ preempt_enable();
+ return 0;
+ }
+ symnum -= kallsyms->num_symtab;
+ }
+ preempt_enable();
+ return -ERANGE;
+}
+
+/* Given a module and name of symbol, find and return the symbol's value */
+unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name)
+{
+ unsigned int i;
+ struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
+
+ for (i = 0; i < kallsyms->num_symtab; i++) {
+ const Elf_Sym *sym = &kallsyms->symtab[i];
+
+ if (strcmp(name, kallsyms_symbol_name(kallsyms, i)) == 0 &&
+ sym->st_shndx != SHN_UNDEF)
+ return kallsyms_symbol_value(sym);
+ }
+ return 0;
+}
+
+/* Look for this name: can be of form module:name. */
+unsigned long module_kallsyms_lookup_name(const char *name)
+{
+ struct module *mod;
+ char *colon;
+ unsigned long ret = 0;
+
+ /* Don't lock: we're in enough trouble already. */
+ preempt_disable();
+ if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) {
+ if ((mod = find_module_all(name, colon - name, false)) != NULL)
+ ret = find_kallsyms_symbol_value(mod, colon + 1);
+ } else {
+ list_for_each_entry_rcu(mod, &modules, list) {
+ if (mod->state == MODULE_STATE_UNFORMED)
+ continue;
+ if ((ret = find_kallsyms_symbol_value(mod, name)) != 0)
+ break;
+ }
+ }
+ preempt_enable();
+ return ret;
+}
+
+#ifdef CONFIG_LIVEPATCH
+int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
+ struct module *, unsigned long),
+ void *data)
+{
+ struct module *mod;
+ unsigned int i;
+ int ret = 0;
+
+ mutex_lock(&module_mutex);
+ list_for_each_entry(mod, &modules, list) {
+ /* We hold module_mutex: no need for rcu_dereference_sched */
+ struct mod_kallsyms *kallsyms = mod->kallsyms;
+
+ if (mod->state == MODULE_STATE_UNFORMED)
+ continue;
+ for (i = 0; i < kallsyms->num_symtab; i++) {
+ const Elf_Sym *sym = &kallsyms->symtab[i];
+
+ if (sym->st_shndx == SHN_UNDEF)
+ continue;
+
+ ret = fn(data, kallsyms_symbol_name(kallsyms, i),
+ mod, kallsyms_symbol_value(sym));
+ if (ret != 0)
+ goto out;
+ }
+ }
+out:
+ mutex_unlock(&module_mutex);
+ return ret;
+}
+#endif /* CONFIG_LIVEPATCH */
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 7dd283959c5c..952079987ea4 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -288,15 +288,6 @@ static bool check_exported_symbol(const struct symsearch *syms,
return true;
}
-static unsigned long kernel_symbol_value(const struct kernel_symbol *sym)
-{
-#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
- return (unsigned long)offset_to_ptr(&sym->value_offset);
-#else
- return sym->value;
-#endif
-}
-
static const char *kernel_symbol_name(const struct kernel_symbol *sym)
{
#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
@@ -317,7 +308,7 @@ static const char *kernel_symbol_namespace(const struct kernel_symbol *sym)
#endif
}
-static int cmp_name(const void *name, const void *sym)
+int cmp_name(const void *name, const void *sym)
{
return strcmp(name, kernel_symbol_name(sym));
}
@@ -387,8 +378,8 @@ static bool find_symbol(struct find_symbol_arg *fsa)
* Search for module by name: must hold module_mutex (or preempt disabled
* for read-only access).
*/
-static struct module *find_module_all(const char *name, size_t len,
- bool even_unformed)
+struct module *find_module_all(const char *name, size_t len,
+ bool even_unformed)
{
struct module *mod;
@@ -1294,13 +1285,6 @@ resolve_symbol_wait(struct module *mod,
return ksym;
}
-#ifdef CONFIG_KALLSYMS
-static inline bool sect_empty(const Elf_Shdr *sect)
-{
- return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
-}
-#endif
-
/*
* /sys/module/foo/sections stuff
* J. Corbet <[email protected]>
@@ -2065,7 +2049,7 @@ unsigned int __weak arch_mod_section_prepend(struct module *mod,
}
/* Update size with this section: return offset. */
-static long get_offset(struct module *mod, unsigned int *size,
+long module_get_offset(struct module *mod, unsigned int *size,
Elf_Shdr *sechdr, unsigned int section)
{
long ret;
@@ -2121,7 +2105,7 @@ static void layout_sections(struct module *mod, struct load_info *info)
|| s->sh_entsize != ~0UL
|| module_init_layout_section(sname))
continue;
- s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
+ s->sh_entsize = module_get_offset(mod, &mod->core_layout.size, s, i);
pr_debug("\t%s\n", sname);
}
switch (m) {
@@ -2154,7 +2138,7 @@ static void layout_sections(struct module *mod, struct load_info *info)
|| s->sh_entsize != ~0UL
|| !module_init_layout_section(sname))
continue;
- s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
+ s->sh_entsize = (module_get_offset(mod, &mod->init_layout.size, s, i)
| INIT_OFFSET_MASK);
pr_debug("\t%s\n", sname);
}
@@ -2267,228 +2251,6 @@ static void free_modinfo(struct module *mod)
}
}
-#ifdef CONFIG_KALLSYMS
-
-/* Lookup exported symbol in given range of kernel_symbols */
-static const struct kernel_symbol *lookup_exported_symbol(const char *name,
- const struct kernel_symbol *start,
- const struct kernel_symbol *stop)
-{
- return bsearch(name, start, stop - start,
- sizeof(struct kernel_symbol), cmp_name);
-}
-
-static int is_exported(const char *name, unsigned long value,
- const struct module *mod)
-{
- const struct kernel_symbol *ks;
- if (!mod)
- ks = lookup_exported_symbol(name, __start___ksymtab, __stop___ksymtab);
- else
- ks = lookup_exported_symbol(name, mod->syms, mod->syms + mod->num_syms);
-
- return ks != NULL && kernel_symbol_value(ks) == value;
-}
-
-/* As per nm */
-static char elf_type(const Elf_Sym *sym, const struct load_info *info)
-{
- const Elf_Shdr *sechdrs = info->sechdrs;
-
- if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
- if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
- return 'v';
- else
- return 'w';
- }
- if (sym->st_shndx == SHN_UNDEF)
- return 'U';
- if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
- return 'a';
- if (sym->st_shndx >= SHN_LORESERVE)
- return '?';
- if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
- return 't';
- if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
- && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
- if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
- return 'r';
- else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
- return 'g';
- else
- return 'd';
- }
- if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
- if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
- return 's';
- else
- return 'b';
- }
- if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
- ".debug")) {
- return 'n';
- }
- return '?';
-}
-
-static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
- unsigned int shnum, unsigned int pcpundx)
-{
- const Elf_Shdr *sec;
-
- if (src->st_shndx == SHN_UNDEF
- || src->st_shndx >= shnum
- || !src->st_name)
- return false;
-
-#ifdef CONFIG_KALLSYMS_ALL
- if (src->st_shndx == pcpundx)
- return true;
-#endif
-
- sec = sechdrs + src->st_shndx;
- if (!(sec->sh_flags & SHF_ALLOC)
-#ifndef CONFIG_KALLSYMS_ALL
- || !(sec->sh_flags & SHF_EXECINSTR)
-#endif
- || (sec->sh_entsize & INIT_OFFSET_MASK))
- return false;
-
- return true;
-}
-
-/*
- * We only allocate and copy the strings needed by the parts of symtab
- * we keep. This is simple, but has the effect of making multiple
- * copies of duplicates. We could be more sophisticated, see
- * linux-kernel thread starting with
- * <73defb5e4bca04a6431392cc341112b1@localhost>.
- */
-static void layout_symtab(struct module *mod, struct load_info *info)
-{
- Elf_Shdr *symsect = info->sechdrs + info->index.sym;
- Elf_Shdr *strsect = info->sechdrs + info->index.str;
- const Elf_Sym *src;
- unsigned int i, nsrc, ndst, strtab_size = 0;
-
- /* Put symbol section at end of init part of module. */
- symsect->sh_flags |= SHF_ALLOC;
- symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
- info->index.sym) | INIT_OFFSET_MASK;
- pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
-
- src = (void *)info->hdr + symsect->sh_offset;
- nsrc = symsect->sh_size / sizeof(*src);
-
- /* Compute total space required for the core symbols' strtab. */
- for (ndst = i = 0; i < nsrc; i++) {
- if (i == 0 || is_livepatch_module(mod) ||
- is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
- info->index.pcpu)) {
- strtab_size += strlen(&info->strtab[src[i].st_name])+1;
- ndst++;
- }
- }
-
- /* Append room for core symbols at end of core part. */
- info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
- info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
- mod->core_layout.size += strtab_size;
- info->core_typeoffs = mod->core_layout.size;
- mod->core_layout.size += ndst * sizeof(char);
- mod->core_layout.size = debug_align(mod->core_layout.size);
-
- /* Put string table section at end of init part of module. */
- strsect->sh_flags |= SHF_ALLOC;
- strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
- info->index.str) | INIT_OFFSET_MASK;
- pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
-
- /* We'll tack temporary mod_kallsyms on the end. */
- mod->init_layout.size = ALIGN(mod->init_layout.size,
- __alignof__(struct mod_kallsyms));
- info->mod_kallsyms_init_off = mod->init_layout.size;
- mod->init_layout.size += sizeof(struct mod_kallsyms);
- info->init_typeoffs = mod->init_layout.size;
- mod->init_layout.size += nsrc * sizeof(char);
- mod->init_layout.size = debug_align(mod->init_layout.size);
-}
-
-/*
- * We use the full symtab and strtab which layout_symtab arranged to
- * be appended to the init section. Later we switch to the cut-down
- * core-only ones.
- */
-static void add_kallsyms(struct module *mod, const struct load_info *info)
-{
- unsigned int i, ndst;
- const Elf_Sym *src;
- Elf_Sym *dst;
- char *s;
- Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
-
- /* Set up to point into init section. */
- mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
-
- mod->kallsyms->symtab = (void *)symsec->sh_addr;
- mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
- /* Make sure we get permanent strtab: don't use info->strtab. */
- mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
- mod->kallsyms->typetab = mod->init_layout.base + info->init_typeoffs;
-
- /*
- * Now populate the cut down core kallsyms for after init
- * and set types up while we still have access to sections.
- */
- mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
- mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
- mod->core_kallsyms.typetab = mod->core_layout.base + info->core_typeoffs;
- src = mod->kallsyms->symtab;
- for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
- mod->kallsyms->typetab[i] = elf_type(src + i, info);
- if (i == 0 || is_livepatch_module(mod) ||
- is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
- info->index.pcpu)) {
- mod->core_kallsyms.typetab[ndst] =
- mod->kallsyms->typetab[i];
- dst[ndst] = src[i];
- dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
- s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
- KSYM_NAME_LEN) + 1;
- }
- }
- mod->core_kallsyms.num_symtab = ndst;
-}
-#else
-static inline void layout_symtab(struct module *mod, struct load_info *info)
-{
-}
-
-static void add_kallsyms(struct module *mod, const struct load_info *info)
-{
-}
-#endif /* CONFIG_KALLSYMS */
-
-#if IS_ENABLED(CONFIG_KALLSYMS) && IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID)
-static void init_build_id(struct module *mod, const struct load_info *info)
-{
- const Elf_Shdr *sechdr;
- unsigned int i;
-
- for (i = 0; i < info->hdr->e_shnum; i++) {
- sechdr = &info->sechdrs[i];
- if (!sect_empty(sechdr) && sechdr->sh_type == SHT_NOTE &&
- !build_id_parse_buf((void *)sechdr->sh_addr, mod->build_id,
- sechdr->sh_size))
- break;
- }
-}
-#else
-static void init_build_id(struct module *mod, const struct load_info *info)
-{
-}
-#endif
-
static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num)
{
if (!debug)
@@ -3799,287 +3561,6 @@ static inline int within(unsigned long addr, void *start, unsigned long size)
return ((void *)addr >= start && (void *)addr < start + size);
}
-#ifdef CONFIG_KALLSYMS
-/*
- * This ignores the intensely annoying "mapping symbols" found
- * in ARM ELF files: $a, $t and $d.
- */
-static inline int is_arm_mapping_symbol(const char *str)
-{
- if (str[0] == '.' && str[1] == 'L')
- return true;
- return str[0] == '$' && strchr("axtd", str[1])
- && (str[2] == '\0' || str[2] == '.');
-}
-
-static const char *kallsyms_symbol_name(struct mod_kallsyms *kallsyms, unsigned int symnum)
-{
- return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
-}
-
-/*
- * Given a module and address, find the corresponding symbol and return its name
- * while providing its size and offset if needed.
- */
-static const char *find_kallsyms_symbol(struct module *mod,
- unsigned long addr,
- unsigned long *size,
- unsigned long *offset)
-{
- unsigned int i, best = 0;
- unsigned long nextval, bestval;
- struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
-
- /* At worse, next value is at end of module */
- if (within_module_init(addr, mod))
- nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
- else
- nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
-
- bestval = kallsyms_symbol_value(&kallsyms->symtab[best]);
-
- /*
- * Scan for closest preceding symbol, and next symbol. (ELF
- * starts real symbols at 1).
- */
- for (i = 1; i < kallsyms->num_symtab; i++) {
- const Elf_Sym *sym = &kallsyms->symtab[i];
- unsigned long thisval = kallsyms_symbol_value(sym);
-
- if (sym->st_shndx == SHN_UNDEF)
- continue;
-
- /*
- * We ignore unnamed symbols: they're uninformative
- * and inserted at a whim.
- */
- if (*kallsyms_symbol_name(kallsyms, i) == '\0'
- || is_arm_mapping_symbol(kallsyms_symbol_name(kallsyms, i)))
- continue;
-
- if (thisval <= addr && thisval > bestval) {
- best = i;
- bestval = thisval;
- }
- if (thisval > addr && thisval < nextval)
- nextval = thisval;
- }
-
- if (!best)
- return NULL;
-
- if (size)
- *size = nextval - bestval;
- if (offset)
- *offset = addr - bestval;
-
- return kallsyms_symbol_name(kallsyms, best);
-}
-
-void * __weak dereference_module_function_descriptor(struct module *mod,
- void *ptr)
-{
- return ptr;
-}
-
-/*
- * For kallsyms to ask for address resolution. NULL means not found. Careful
- * not to lock to avoid deadlock on oopses, simply disable preemption.
- */
-const char *module_address_lookup(unsigned long addr,
- unsigned long *size,
- unsigned long *offset,
- char **modname,
- const unsigned char **modbuildid,
- char *namebuf)
-{
- const char *ret = NULL;
- struct module *mod;
-
- preempt_disable();
- mod = __module_address(addr);
- if (mod) {
- if (modname)
- *modname = mod->name;
- if (modbuildid) {
-#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID)
- *modbuildid = mod->build_id;
-#else
- *modbuildid = NULL;
-#endif
- }
-
- ret = find_kallsyms_symbol(mod, addr, size, offset);
- }
- /* Make a copy in here where it's safe */
- if (ret) {
- strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
- ret = namebuf;
- }
- preempt_enable();
-
- return ret;
-}
-
-int lookup_module_symbol_name(unsigned long addr, char *symname)
-{
- struct module *mod;
-
- preempt_disable();
- list_for_each_entry_rcu(mod, &modules, list) {
- if (mod->state == MODULE_STATE_UNFORMED)
- continue;
- if (within_module(addr, mod)) {
- const char *sym;
-
- sym = find_kallsyms_symbol(mod, addr, NULL, NULL);
- if (!sym)
- goto out;
-
- strlcpy(symname, sym, KSYM_NAME_LEN);
- preempt_enable();
- return 0;
- }
- }
-out:
- preempt_enable();
- return -ERANGE;
-}
-
-int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
- unsigned long *offset, char *modname, char *name)
-{
- struct module *mod;
-
- preempt_disable();
- list_for_each_entry_rcu(mod, &modules, list) {
- if (mod->state == MODULE_STATE_UNFORMED)
- continue;
- if (within_module(addr, mod)) {
- const char *sym;
-
- sym = find_kallsyms_symbol(mod, addr, size, offset);
- if (!sym)
- goto out;
- if (modname)
- strlcpy(modname, mod->name, MODULE_NAME_LEN);
- if (name)
- strlcpy(name, sym, KSYM_NAME_LEN);
- preempt_enable();
- return 0;
- }
- }
-out:
- preempt_enable();
- return -ERANGE;
-}
-
-int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
- char *name, char *module_name, int *exported)
-{
- struct module *mod;
-
- preempt_disable();
- list_for_each_entry_rcu(mod, &modules, list) {
- struct mod_kallsyms *kallsyms;
-
- if (mod->state == MODULE_STATE_UNFORMED)
- continue;
- kallsyms = rcu_dereference_sched(mod->kallsyms);
- if (symnum < kallsyms->num_symtab) {
- const Elf_Sym *sym = &kallsyms->symtab[symnum];
-
- *value = kallsyms_symbol_value(sym);
- *type = kallsyms->typetab[symnum];
- strlcpy(name, kallsyms_symbol_name(kallsyms, symnum), KSYM_NAME_LEN);
- strlcpy(module_name, mod->name, MODULE_NAME_LEN);
- *exported = is_exported(name, *value, mod);
- preempt_enable();
- return 0;
- }
- symnum -= kallsyms->num_symtab;
- }
- preempt_enable();
- return -ERANGE;
-}
-
-/* Given a module and name of symbol, find and return the symbol's value */
-static unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name)
-{
- unsigned int i;
- struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
-
- for (i = 0; i < kallsyms->num_symtab; i++) {
- const Elf_Sym *sym = &kallsyms->symtab[i];
-
- if (strcmp(name, kallsyms_symbol_name(kallsyms, i)) == 0 &&
- sym->st_shndx != SHN_UNDEF)
- return kallsyms_symbol_value(sym);
- }
- return 0;
-}
-
-/* Look for this name: can be of form module:name. */
-unsigned long module_kallsyms_lookup_name(const char *name)
-{
- struct module *mod;
- char *colon;
- unsigned long ret = 0;
-
- /* Don't lock: we're in enough trouble already. */
- preempt_disable();
- if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) {
- if ((mod = find_module_all(name, colon - name, false)) != NULL)
- ret = find_kallsyms_symbol_value(mod, colon+1);
- } else {
- list_for_each_entry_rcu(mod, &modules, list) {
- if (mod->state == MODULE_STATE_UNFORMED)
- continue;
- if ((ret = find_kallsyms_symbol_value(mod, name)) != 0)
- break;
- }
- }
- preempt_enable();
- return ret;
-}
-
-#ifdef CONFIG_LIVEPATCH
-int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
- struct module *, unsigned long),
- void *data)
-{
- struct module *mod;
- unsigned int i;
- int ret = 0;
-
- mutex_lock(&module_mutex);
- list_for_each_entry(mod, &modules, list) {
- /* We hold module_mutex: no need for rcu_dereference_sched */
- struct mod_kallsyms *kallsyms = mod->kallsyms;
-
- if (mod->state == MODULE_STATE_UNFORMED)
- continue;
- for (i = 0; i < kallsyms->num_symtab; i++) {
- const Elf_Sym *sym = &kallsyms->symtab[i];
-
- if (sym->st_shndx == SHN_UNDEF)
- continue;
-
- ret = fn(data, kallsyms_symbol_name(kallsyms, i),
- mod, kallsyms_symbol_value(sym));
- if (ret != 0)
- goto out;
-
- cond_resched();
- }
- }
-out:
- mutex_unlock(&module_mutex);
- return ret;
-}
-#endif /* CONFIG_LIVEPATCH */
-#endif /* CONFIG_KALLSYMS */
-
static void cfi_init(struct module *mod)
{
#ifdef CONFIG_CFI_CLANG
--
2.34.1
Hi Luis,
Le 07/03/2022 à 22:05, Luis Chamberlain a écrit :
> On Mon, Mar 07, 2022 at 05:44:55PM +0000, Aaron Tomlin wrote:
>> Hi Luis,
>>
>> As per your suggestion [1], this is an attempt to refactor and split
>> optional code out of core module support code into separate components.
>> This version is based on Linus' commit 7993e65fdd0f ("Merge tag
>> 'mtd/fixes-for-5.17-rc5' of
>> git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux").
>
> Thanks! Pushed out to modules-testing to see what 0-day can find.
> Further review from others is welcomed in the meantime. If no issues
> are found, we also get kmod testing done, and more reviews, I can
> push then later to modules-next for further testing on linux-next.
>
As far as I understood kmod testing doesn't test the kernel at all so it
won't test any of our changes.
In his mail last week, Lucas said: "kmod's testsuite don't test anything
on the kernel side... the kernel part is mocked by the testsuite itself."
Christophe
No functional change.
This patch migrates kmemleak code out of core module
code into kernel/module/debug_kmemleak.c
Reviewed-by: Christophe Leroy <[email protected]>
Signed-off-by: Aaron Tomlin <[email protected]>
---
kernel/module/Makefile | 1 +
kernel/module/debug_kmemleak.c | 30 ++++++++++++++++++++++++++++++
kernel/module/internal.h | 7 +++++++
kernel/module/main.c | 27 ---------------------------
4 files changed, 38 insertions(+), 27 deletions(-)
create mode 100644 kernel/module/debug_kmemleak.c
diff --git a/kernel/module/Makefile b/kernel/module/Makefile
index d313c8472cb3..12388627725c 100644
--- a/kernel/module/Makefile
+++ b/kernel/module/Makefile
@@ -13,3 +13,4 @@ obj-$(CONFIG_MODULE_SIG) += signing.o
obj-$(CONFIG_LIVEPATCH) += livepatch.o
obj-$(CONFIG_MODULES_TREE_LOOKUP) += tree_lookup.o
obj-$(CONFIG_STRICT_MODULE_RWX) += strict_rwx.o
+obj-$(CONFIG_DEBUG_KMEMLEAK) += debug_kmemleak.o
diff --git a/kernel/module/debug_kmemleak.c b/kernel/module/debug_kmemleak.c
new file mode 100644
index 000000000000..12a569d361e8
--- /dev/null
+++ b/kernel/module/debug_kmemleak.c
@@ -0,0 +1,30 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Module kmemleak support
+ *
+ * Copyright (C) 2009 Catalin Marinas
+ */
+
+#include <linux/module.h>
+#include <linux/kmemleak.h>
+#include "internal.h"
+
+void kmemleak_load_module(const struct module *mod,
+ const struct load_info *info)
+{
+ unsigned int i;
+
+ /* only scan the sections containing data */
+ kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
+
+ for (i = 1; i < info->hdr->e_shnum; i++) {
+ /* Scan all writable sections that's not executable */
+ if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
+ !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
+ (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
+ continue;
+
+ kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
+ info->sechdrs[i].sh_size, GFP_KERNEL);
+ }
+}
diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index d6f646a5da41..b0c360839f63 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -167,3 +167,10 @@ static inline int module_sig_check(struct load_info *info, int flags)
return 0;
}
#endif /* !CONFIG_MODULE_SIG */
+
+#ifdef CONFIG_DEBUG_KMEMLEAK
+void kmemleak_load_module(const struct module *mod, const struct load_info *info);
+#else /* !CONFIG_DEBUG_KMEMLEAK */
+static inline void kmemleak_load_module(const struct module *mod,
+ const struct load_info *info) { }
+#endif /* CONFIG_DEBUG_KMEMLEAK */
diff --git a/kernel/module/main.c b/kernel/module/main.c
index c63e10c61694..7dd283959c5c 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -2519,33 +2519,6 @@ bool __weak module_exit_section(const char *name)
return strstarts(name, ".exit");
}
-#ifdef CONFIG_DEBUG_KMEMLEAK
-static void kmemleak_load_module(const struct module *mod,
- const struct load_info *info)
-{
- unsigned int i;
-
- /* only scan the sections containing data */
- kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
-
- for (i = 1; i < info->hdr->e_shnum; i++) {
- /* Scan all writable sections that's not executable */
- if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
- !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
- (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
- continue;
-
- kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
- info->sechdrs[i].sh_size, GFP_KERNEL);
- }
-}
-#else
-static inline void kmemleak_load_module(const struct module *mod,
- const struct load_info *info)
-{
-}
-#endif
-
static int validate_section_offset(struct load_info *info, Elf_Shdr *shdr)
{
#if defined(CONFIG_64BIT)
--
2.34.1
No functional changes.
This patch moves all module related code into a separate directory,
modifies each file name and creates a new Makefile. Note: this effort
is in preparation to refactor core module code.
Reviewed-by: Christophe Leroy <[email protected]>
Signed-off-by: Aaron Tomlin <[email protected]>
---
MAINTAINERS | 2 +-
kernel/Makefile | 5 +----
kernel/module/Makefile | 12 ++++++++++++
kernel/{module_decompress.c => module/decompress.c} | 2 +-
kernel/{module-internal.h => module/internal.h} | 0
kernel/{module.c => module/main.c} | 2 +-
kernel/{module_signing.c => module/signing.c} | 2 +-
7 files changed, 17 insertions(+), 8 deletions(-)
create mode 100644 kernel/module/Makefile
rename kernel/{module_decompress.c => module/decompress.c} (99%)
rename kernel/{module-internal.h => module/internal.h} (100%)
rename kernel/{module.c => module/main.c} (99%)
rename kernel/{module_signing.c => module/signing.c} (97%)
diff --git a/MAINTAINERS b/MAINTAINERS
index bd86ed9fbc79..463bdb829db4 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13012,7 +13012,7 @@ L: [email protected]
S: Maintained
T: git git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux.git modules-next
F: include/linux/module.h
-F: kernel/module.c
+F: kernel/module/
MONOLITHIC POWER SYSTEM PMIC DRIVER
M: Saravanan Sekar <[email protected]>
diff --git a/kernel/Makefile b/kernel/Makefile
index 56f4ee97f328..717075b65deb 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -29,7 +29,6 @@ KCOV_INSTRUMENT_softirq.o := n
KCSAN_SANITIZE_softirq.o = n
# These are called from save_stack_trace() on slub debug path,
# and produce insane amounts of uninteresting coverage.
-KCOV_INSTRUMENT_module.o := n
KCOV_INSTRUMENT_extable.o := n
KCOV_INSTRUMENT_stacktrace.o := n
# Don't self-instrument.
@@ -53,6 +52,7 @@ obj-y += rcu/
obj-y += livepatch/
obj-y += dma/
obj-y += entry/
+obj-$(CONFIG_MODULES) += module/
obj-$(CONFIG_KCMP) += kcmp.o
obj-$(CONFIG_FREEZER) += freezer.o
@@ -66,9 +66,6 @@ ifneq ($(CONFIG_SMP),y)
obj-y += up.o
endif
obj-$(CONFIG_UID16) += uid16.o
-obj-$(CONFIG_MODULES) += module.o
-obj-$(CONFIG_MODULE_DECOMPRESS) += module_decompress.o
-obj-$(CONFIG_MODULE_SIG) += module_signing.o
obj-$(CONFIG_MODULE_SIG_FORMAT) += module_signature.o
obj-$(CONFIG_KALLSYMS) += kallsyms.o
obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o
diff --git a/kernel/module/Makefile b/kernel/module/Makefile
new file mode 100644
index 000000000000..cdd5c61b8c7f
--- /dev/null
+++ b/kernel/module/Makefile
@@ -0,0 +1,12 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for linux kernel module support
+#
+
+# These are called from save_stack_trace() on slub debug path,
+# and produce insane amounts of uninteresting coverage.
+KCOV_INSTRUMENT_module.o := n
+
+obj-y += main.o
+obj-$(CONFIG_MODULE_DECOMPRESS) += decompress.o
+obj-$(CONFIG_MODULE_SIG) += signing.o
diff --git a/kernel/module_decompress.c b/kernel/module/decompress.c
similarity index 99%
rename from kernel/module_decompress.c
rename to kernel/module/decompress.c
index ffef98a20320..d14d6443225a 100644
--- a/kernel/module_decompress.c
+++ b/kernel/module/decompress.c
@@ -12,7 +12,7 @@
#include <linux/sysfs.h>
#include <linux/vmalloc.h>
-#include "module-internal.h"
+#include "internal.h"
static int module_extend_max_pages(struct load_info *info, unsigned int extent)
{
diff --git a/kernel/module-internal.h b/kernel/module/internal.h
similarity index 100%
rename from kernel/module-internal.h
rename to kernel/module/internal.h
diff --git a/kernel/module.c b/kernel/module/main.c
similarity index 99%
rename from kernel/module.c
rename to kernel/module/main.c
index 46a5c2ed1928..34a2b0cf3c3e 100644
--- a/kernel/module.c
+++ b/kernel/module/main.c
@@ -58,7 +58,7 @@
#include <linux/dynamic_debug.h>
#include <linux/audit.h>
#include <uapi/linux/module.h>
-#include "module-internal.h"
+#include "internal.h"
#define CREATE_TRACE_POINTS
#include <trace/events/module.h>
diff --git a/kernel/module_signing.c b/kernel/module/signing.c
similarity index 97%
rename from kernel/module_signing.c
rename to kernel/module/signing.c
index 8723ae70ea1f..8aeb6d2ee94b 100644
--- a/kernel/module_signing.c
+++ b/kernel/module/signing.c
@@ -12,7 +12,7 @@
#include <linux/string.h>
#include <linux/verification.h>
#include <crypto/public_key.h>
-#include "module-internal.h"
+#include "internal.h"
/*
* Verify the signature on a module.
--
2.34.1
No functional change.
This patch makes it possible to move non-essential code
out of core module code.
Reviewed-by: Christophe Leroy <[email protected]>
Signed-off-by: Aaron Tomlin <[email protected]>
---
kernel/module/internal.h | 21 +++++++++++++++++++++
kernel/module/main.c | 22 ++--------------------
2 files changed, 23 insertions(+), 20 deletions(-)
diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index 8c381c99062f..ea8c4c02614c 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -7,6 +7,27 @@
#include <linux/elf.h>
#include <asm/module.h>
+#include <linux/mutex.h>
+
+#ifndef ARCH_SHF_SMALL
+#define ARCH_SHF_SMALL 0
+#endif
+
+/* If this is set, the section belongs in the init part of the module */
+#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG - 1))
+/* Maximum number of characters written by module_flags() */
+#define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
+
+extern struct mutex module_mutex;
+extern struct list_head modules;
+
+/* Provided by the linker */
+extern const struct kernel_symbol __start___ksymtab[];
+extern const struct kernel_symbol __stop___ksymtab[];
+extern const struct kernel_symbol __start___ksymtab_gpl[];
+extern const struct kernel_symbol __stop___ksymtab_gpl[];
+extern const s32 __start___kcrctab[];
+extern const s32 __start___kcrctab_gpl[];
struct load_info {
const char *name;
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 34a2b0cf3c3e..5f5e21f972dd 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -63,10 +63,6 @@
#define CREATE_TRACE_POINTS
#include <trace/events/module.h>
-#ifndef ARCH_SHF_SMALL
-#define ARCH_SHF_SMALL 0
-#endif
-
/*
* Modules' sections will be aligned on page boundaries
* to ensure complete separation of code and data, but
@@ -78,9 +74,6 @@
# define debug_align(X) (X)
#endif
-/* If this is set, the section belongs in the init part of the module */
-#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
-
/*
* Mutex protects:
* 1) List of modules (also safely readable with preempt_disable),
@@ -88,8 +81,8 @@
* 3) module_addr_min/module_addr_max.
* (delete and add uses RCU list operations).
*/
-static DEFINE_MUTEX(module_mutex);
-static LIST_HEAD(modules);
+DEFINE_MUTEX(module_mutex);
+LIST_HEAD(modules);
/* Work queue for freeing init sections in success case */
static void do_free_init(struct work_struct *w);
@@ -408,14 +401,6 @@ static __maybe_unused void *any_section_objs(const struct load_info *info,
return (void *)info->sechdrs[sec].sh_addr;
}
-/* Provided by the linker */
-extern const struct kernel_symbol __start___ksymtab[];
-extern const struct kernel_symbol __stop___ksymtab[];
-extern const struct kernel_symbol __start___ksymtab_gpl[];
-extern const struct kernel_symbol __stop___ksymtab_gpl[];
-extern const s32 __start___kcrctab[];
-extern const s32 __start___kcrctab_gpl[];
-
#ifndef CONFIG_MODVERSIONS
#define symversion(base, idx) NULL
#else
@@ -4542,9 +4527,6 @@ static void cfi_cleanup(struct module *mod)
#endif
}
-/* Maximum number of characters written by module_flags() */
-#define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
-
/* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
static char *module_flags(struct module *mod, char *buf)
{
--
2.34.1
No functional change.
This patch migrates module latched RB-tree support
(e.g. see __module_address()) from core module code
into kernel/module/tree_lookup.c.
Reviewed-by: Christophe Leroy <[email protected]>
Signed-off-by: Aaron Tomlin <[email protected]>
---
kernel/module/Makefile | 1 +
kernel/module/internal.h | 33 +++++++++
kernel/module/main.c | 130 ++----------------------------------
kernel/module/tree_lookup.c | 109 ++++++++++++++++++++++++++++++
4 files changed, 147 insertions(+), 126 deletions(-)
create mode 100644 kernel/module/tree_lookup.c
diff --git a/kernel/module/Makefile b/kernel/module/Makefile
index ed3aacb04f17..88774e386276 100644
--- a/kernel/module/Makefile
+++ b/kernel/module/Makefile
@@ -11,3 +11,4 @@ obj-y += main.o
obj-$(CONFIG_MODULE_DECOMPRESS) += decompress.o
obj-$(CONFIG_MODULE_SIG) += signing.o
obj-$(CONFIG_LIVEPATCH) += livepatch.o
+obj-$(CONFIG_MODULES_TREE_LOOKUP) += tree_lookup.o
diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index ad7a444253ed..f1682e3677be 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -9,6 +9,7 @@
#include <linux/compiler.h>
#include <linux/module.h>
#include <linux/mutex.h>
+#include <linux/rculist.h>
#ifndef ARCH_SHF_SMALL
#define ARCH_SHF_SMALL 0
@@ -93,3 +94,35 @@ static inline void module_decompress_cleanup(struct load_info *info)
{
}
#endif
+
+#ifdef CONFIG_MODULES_TREE_LOOKUP
+struct mod_tree_root {
+ struct latch_tree_root root;
+ unsigned long addr_min;
+ unsigned long addr_max;
+};
+
+extern struct mod_tree_root mod_tree;
+
+void mod_tree_insert(struct module *mod);
+void mod_tree_remove_init(struct module *mod);
+void mod_tree_remove(struct module *mod);
+struct module *mod_find(unsigned long addr);
+#else /* !CONFIG_MODULES_TREE_LOOKUP */
+
+static inline void mod_tree_insert(struct module *mod) { }
+static inline void mod_tree_remove_init(struct module *mod) { }
+static inline void mod_tree_remove(struct module *mod) { }
+static inline struct module *mod_find(unsigned long addr)
+{
+ struct module *mod;
+
+ list_for_each_entry_rcu(mod, &modules, list,
+ lockdep_is_held(&module_mutex)) {
+ if (within_module(addr, mod))
+ return mod;
+ }
+
+ return NULL;
+}
+#endif /* CONFIG_MODULES_TREE_LOOKUP */
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 3596ebf3a6c3..76b53880ad91 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -90,138 +90,16 @@ static DECLARE_WORK(init_free_wq, do_free_init);
static LLIST_HEAD(init_free_list);
#ifdef CONFIG_MODULES_TREE_LOOKUP
-
-/*
- * Use a latched RB-tree for __module_address(); this allows us to use
- * RCU-sched lookups of the address from any context.
- *
- * This is conditional on PERF_EVENTS || TRACING because those can really hit
- * __module_address() hard by doing a lot of stack unwinding; potentially from
- * NMI context.
- */
-
-static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
-{
- struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
-
- return (unsigned long)layout->base;
-}
-
-static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
-{
- struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
-
- return (unsigned long)layout->size;
-}
-
-static __always_inline bool
-mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
-{
- return __mod_tree_val(a) < __mod_tree_val(b);
-}
-
-static __always_inline int
-mod_tree_comp(void *key, struct latch_tree_node *n)
-{
- unsigned long val = (unsigned long)key;
- unsigned long start, end;
-
- start = __mod_tree_val(n);
- if (val < start)
- return -1;
-
- end = start + __mod_tree_size(n);
- if (val >= end)
- return 1;
-
- return 0;
-}
-
-static const struct latch_tree_ops mod_tree_ops = {
- .less = mod_tree_less,
- .comp = mod_tree_comp,
-};
-
-static struct mod_tree_root {
- struct latch_tree_root root;
- unsigned long addr_min;
- unsigned long addr_max;
-} mod_tree __cacheline_aligned = {
+struct mod_tree_root mod_tree __cacheline_aligned = {
.addr_min = -1UL,
};
#define module_addr_min mod_tree.addr_min
#define module_addr_max mod_tree.addr_max
-static noinline void __mod_tree_insert(struct mod_tree_node *node)
-{
- latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
-}
-
-static void __mod_tree_remove(struct mod_tree_node *node)
-{
- latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
-}
-
-/*
- * These modifications: insert, remove_init and remove; are serialized by the
- * module_mutex.
- */
-static void mod_tree_insert(struct module *mod)
-{
- mod->core_layout.mtn.mod = mod;
- mod->init_layout.mtn.mod = mod;
-
- __mod_tree_insert(&mod->core_layout.mtn);
- if (mod->init_layout.size)
- __mod_tree_insert(&mod->init_layout.mtn);
-}
-
-static void mod_tree_remove_init(struct module *mod)
-{
- if (mod->init_layout.size)
- __mod_tree_remove(&mod->init_layout.mtn);
-}
-
-static void mod_tree_remove(struct module *mod)
-{
- __mod_tree_remove(&mod->core_layout.mtn);
- mod_tree_remove_init(mod);
-}
-
-static struct module *mod_find(unsigned long addr)
-{
- struct latch_tree_node *ltn;
-
- ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
- if (!ltn)
- return NULL;
-
- return container_of(ltn, struct mod_tree_node, node)->mod;
-}
-
-#else /* MODULES_TREE_LOOKUP */
-
-static unsigned long module_addr_min = -1UL, module_addr_max = 0;
-
-static void mod_tree_insert(struct module *mod) { }
-static void mod_tree_remove_init(struct module *mod) { }
-static void mod_tree_remove(struct module *mod) { }
-
-static struct module *mod_find(unsigned long addr)
-{
- struct module *mod;
-
- list_for_each_entry_rcu(mod, &modules, list,
- lockdep_is_held(&module_mutex)) {
- if (within_module(addr, mod))
- return mod;
- }
-
- return NULL;
-}
-
-#endif /* MODULES_TREE_LOOKUP */
+#else /* !CONFIG_MODULES_TREE_LOOKUP */
+static unsigned long module_addr_min = -1UL, module_addr_max;
+#endif /* CONFIG_MODULES_TREE_LOOKUP */
/*
* Bounds of module text, for speeding up __module_address.
diff --git a/kernel/module/tree_lookup.c b/kernel/module/tree_lookup.c
new file mode 100644
index 000000000000..0bc4ec3b22ce
--- /dev/null
+++ b/kernel/module/tree_lookup.c
@@ -0,0 +1,109 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Modules tree lookup
+ *
+ * Copyright (C) 2015 Peter Zijlstra
+ * Copyright (C) 2015 Rusty Russell
+ */
+
+#include <linux/module.h>
+#include <linux/rbtree_latch.h>
+#include "internal.h"
+
+/*
+ * Use a latched RB-tree for __module_address(); this allows us to use
+ * RCU-sched lookups of the address from any context.
+ *
+ * This is conditional on PERF_EVENTS || TRACING because those can really hit
+ * __module_address() hard by doing a lot of stack unwinding; potentially from
+ * NMI context.
+ */
+
+static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
+{
+ struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
+
+ return (unsigned long)layout->base;
+}
+
+static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
+{
+ struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
+
+ return (unsigned long)layout->size;
+}
+
+static __always_inline bool
+mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
+{
+ return __mod_tree_val(a) < __mod_tree_val(b);
+}
+
+static __always_inline int
+mod_tree_comp(void *key, struct latch_tree_node *n)
+{
+ unsigned long val = (unsigned long)key;
+ unsigned long start, end;
+
+ start = __mod_tree_val(n);
+ if (val < start)
+ return -1;
+
+ end = start + __mod_tree_size(n);
+ if (val >= end)
+ return 1;
+
+ return 0;
+}
+
+static const struct latch_tree_ops mod_tree_ops = {
+ .less = mod_tree_less,
+ .comp = mod_tree_comp,
+};
+
+static noinline void __mod_tree_insert(struct mod_tree_node *node)
+{
+ latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
+}
+
+static void __mod_tree_remove(struct mod_tree_node *node)
+{
+ latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
+}
+
+/*
+ * These modifications: insert, remove_init and remove; are serialized by the
+ * module_mutex.
+ */
+void mod_tree_insert(struct module *mod)
+{
+ mod->core_layout.mtn.mod = mod;
+ mod->init_layout.mtn.mod = mod;
+
+ __mod_tree_insert(&mod->core_layout.mtn);
+ if (mod->init_layout.size)
+ __mod_tree_insert(&mod->init_layout.mtn);
+}
+
+void mod_tree_remove_init(struct module *mod)
+{
+ if (mod->init_layout.size)
+ __mod_tree_remove(&mod->init_layout.mtn);
+}
+
+void mod_tree_remove(struct module *mod)
+{
+ __mod_tree_remove(&mod->core_layout.mtn);
+ mod_tree_remove_init(mod);
+}
+
+struct module *mod_find(unsigned long addr)
+{
+ struct latch_tree_node *ltn;
+
+ ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
+ if (!ltn)
+ return NULL;
+
+ return container_of(ltn, struct mod_tree_node, node)->mod;
+}
--
2.34.1
No functional change.
This patch migrates code that makes module text
and rodata memory read-only and non-text memory
non-executable from core module code into
kernel/module/strict_rwx.c.
Reviewed-by: Christophe Leroy <[email protected]>
Signed-off-by: Aaron Tomlin <[email protected]>
---
kernel/module/Makefile | 1 +
kernel/module/internal.h | 32 ++++++++++++
kernel/module/main.c | 99 +-------------------------------------
kernel/module/strict_rwx.c | 85 ++++++++++++++++++++++++++++++++
4 files changed, 120 insertions(+), 97 deletions(-)
create mode 100644 kernel/module/strict_rwx.c
diff --git a/kernel/module/Makefile b/kernel/module/Makefile
index 88774e386276..d313c8472cb3 100644
--- a/kernel/module/Makefile
+++ b/kernel/module/Makefile
@@ -12,3 +12,4 @@ obj-$(CONFIG_MODULE_DECOMPRESS) += decompress.o
obj-$(CONFIG_MODULE_SIG) += signing.o
obj-$(CONFIG_LIVEPATCH) += livepatch.o
obj-$(CONFIG_MODULES_TREE_LOOKUP) += tree_lookup.o
+obj-$(CONFIG_STRICT_MODULE_RWX) += strict_rwx.o
diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index f1682e3677be..a6895bb5598a 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -20,6 +20,17 @@
/* Maximum number of characters written by module_flags() */
#define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
+/*
+ * Modules' sections will be aligned on page boundaries
+ * to ensure complete separation of code and data, but
+ * only when CONFIG_ARCH_HAS_STRICT_MODULE_RWX=y
+ */
+#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
+# define debug_align(X) PAGE_ALIGN(X)
+#else
+# define debug_align(X) (X)
+#endif
+
extern struct mutex module_mutex;
extern struct list_head modules;
@@ -126,3 +137,24 @@ static inline struct module *mod_find(unsigned long addr)
return NULL;
}
#endif /* CONFIG_MODULES_TREE_LOOKUP */
+
+#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
+void frob_text(const struct module_layout *layout, int (*set_memory)(unsigned long start,
+ int num_pages));
+#endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
+
+#ifdef CONFIG_STRICT_MODULE_RWX
+void module_enable_ro(const struct module *mod, bool after_init);
+void module_enable_nx(const struct module *mod);
+int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
+ char *secstrings, struct module *mod);
+
+#else /* !CONFIG_STRICT_MODULE_RWX */
+static inline void module_enable_nx(const struct module *mod) { }
+static inline void module_enable_ro(const struct module *mod, bool after_init) {}
+static inline int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
+ char *secstrings, struct module *mod)
+{
+ return 0;
+}
+#endif /* CONFIG_STRICT_MODULE_RWX */
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 76b53880ad91..5cd63f14b1ef 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -63,17 +63,6 @@
#define CREATE_TRACE_POINTS
#include <trace/events/module.h>
-/*
- * Modules' sections will be aligned on page boundaries
- * to ensure complete separation of code and data, but
- * only when CONFIG_ARCH_HAS_STRICT_MODULE_RWX=y
- */
-#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
-# define debug_align(X) ALIGN(X, PAGE_SIZE)
-#else
-# define debug_align(X) (X)
-#endif
-
/*
* Mutex protects:
* 1) List of modules (also safely readable with preempt_disable),
@@ -1819,8 +1808,8 @@ static void mod_sysfs_teardown(struct module *mod)
* whether we are strict.
*/
#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
-static void frob_text(const struct module_layout *layout,
- int (*set_memory)(unsigned long start, int num_pages))
+void frob_text(const struct module_layout *layout,
+ int (*set_memory)(unsigned long start, int num_pages))
{
BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
@@ -1837,90 +1826,6 @@ static void module_enable_x(const struct module *mod)
static void module_enable_x(const struct module *mod) { }
#endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
-#ifdef CONFIG_STRICT_MODULE_RWX
-static void frob_rodata(const struct module_layout *layout,
- int (*set_memory)(unsigned long start, int num_pages))
-{
- BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
- BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
- BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
- set_memory((unsigned long)layout->base + layout->text_size,
- (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
-}
-
-static void frob_ro_after_init(const struct module_layout *layout,
- int (*set_memory)(unsigned long start, int num_pages))
-{
- BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
- BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
- BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
- set_memory((unsigned long)layout->base + layout->ro_size,
- (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
-}
-
-static void frob_writable_data(const struct module_layout *layout,
- int (*set_memory)(unsigned long start, int num_pages))
-{
- BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
- BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
- BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
- set_memory((unsigned long)layout->base + layout->ro_after_init_size,
- (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
-}
-
-static void module_enable_ro(const struct module *mod, bool after_init)
-{
- if (!rodata_enabled)
- return;
-
- set_vm_flush_reset_perms(mod->core_layout.base);
- set_vm_flush_reset_perms(mod->init_layout.base);
- frob_text(&mod->core_layout, set_memory_ro);
-
- frob_rodata(&mod->core_layout, set_memory_ro);
- frob_text(&mod->init_layout, set_memory_ro);
- frob_rodata(&mod->init_layout, set_memory_ro);
-
- if (after_init)
- frob_ro_after_init(&mod->core_layout, set_memory_ro);
-}
-
-static void module_enable_nx(const struct module *mod)
-{
- frob_rodata(&mod->core_layout, set_memory_nx);
- frob_ro_after_init(&mod->core_layout, set_memory_nx);
- frob_writable_data(&mod->core_layout, set_memory_nx);
- frob_rodata(&mod->init_layout, set_memory_nx);
- frob_writable_data(&mod->init_layout, set_memory_nx);
-}
-
-static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
- char *secstrings, struct module *mod)
-{
- const unsigned long shf_wx = SHF_WRITE|SHF_EXECINSTR;
- int i;
-
- for (i = 0; i < hdr->e_shnum; i++) {
- if ((sechdrs[i].sh_flags & shf_wx) == shf_wx) {
- pr_err("%s: section %s (index %d) has invalid WRITE|EXEC flags\n",
- mod->name, secstrings + sechdrs[i].sh_name, i);
- return -ENOEXEC;
- }
- }
-
- return 0;
-}
-
-#else /* !CONFIG_STRICT_MODULE_RWX */
-static void module_enable_nx(const struct module *mod) { }
-static void module_enable_ro(const struct module *mod, bool after_init) {}
-static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
- char *secstrings, struct module *mod)
-{
- return 0;
-}
-#endif /* CONFIG_STRICT_MODULE_RWX */
-
void __weak module_memfree(void *module_region)
{
/*
diff --git a/kernel/module/strict_rwx.c b/kernel/module/strict_rwx.c
new file mode 100644
index 000000000000..7949dfd449c2
--- /dev/null
+++ b/kernel/module/strict_rwx.c
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Module strict rwx
+ *
+ * Copyright (C) 2015 Rusty Russell
+ */
+
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/vmalloc.h>
+#include <linux/set_memory.h>
+#include "internal.h"
+
+static void frob_rodata(const struct module_layout *layout,
+ int (*set_memory)(unsigned long start, int num_pages))
+{
+ BUG_ON(!PAGE_ALIGNED(layout->base));
+ BUG_ON(!PAGE_ALIGNED(layout->text_size));
+ BUG_ON(!PAGE_ALIGNED(layout->ro_size));
+ set_memory((unsigned long)layout->base + layout->text_size,
+ (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
+}
+
+static void frob_ro_after_init(const struct module_layout *layout,
+ int (*set_memory)(unsigned long start, int num_pages))
+{
+ BUG_ON(!PAGE_ALIGNED(layout->base));
+ BUG_ON(!PAGE_ALIGNED(layout->ro_size));
+ BUG_ON(!PAGE_ALIGNED(layout->ro_after_init_size));
+ set_memory((unsigned long)layout->base + layout->ro_size,
+ (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
+}
+
+static void frob_writable_data(const struct module_layout *layout,
+ int (*set_memory)(unsigned long start, int num_pages))
+{
+ BUG_ON(!PAGE_ALIGNED(layout->base));
+ BUG_ON(!PAGE_ALIGNED(layout->ro_after_init_size));
+ BUG_ON(!PAGE_ALIGNED(layout->size));
+ set_memory((unsigned long)layout->base + layout->ro_after_init_size,
+ (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
+}
+
+void module_enable_ro(const struct module *mod, bool after_init)
+{
+ if (!rodata_enabled)
+ return;
+
+ set_vm_flush_reset_perms(mod->core_layout.base);
+ set_vm_flush_reset_perms(mod->init_layout.base);
+ frob_text(&mod->core_layout, set_memory_ro);
+
+ frob_rodata(&mod->core_layout, set_memory_ro);
+ frob_text(&mod->init_layout, set_memory_ro);
+ frob_rodata(&mod->init_layout, set_memory_ro);
+
+ if (after_init)
+ frob_ro_after_init(&mod->core_layout, set_memory_ro);
+}
+
+void module_enable_nx(const struct module *mod)
+{
+ frob_rodata(&mod->core_layout, set_memory_nx);
+ frob_ro_after_init(&mod->core_layout, set_memory_nx);
+ frob_writable_data(&mod->core_layout, set_memory_nx);
+ frob_rodata(&mod->init_layout, set_memory_nx);
+ frob_writable_data(&mod->init_layout, set_memory_nx);
+}
+
+int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
+ char *secstrings, struct module *mod)
+{
+ const unsigned long shf_wx = SHF_WRITE | SHF_EXECINSTR;
+ int i;
+
+ for (i = 0; i < hdr->e_shnum; i++) {
+ if ((sechdrs[i].sh_flags & shf_wx) == shf_wx) {
+ pr_err("%s: section %s (index %d) has invalid WRITE|EXEC flags\n",
+ mod->name, secstrings + sechdrs[i].sh_name, i);
+ return -ENOEXEC;
+ }
+ }
+
+ return 0;
+}
--
2.34.1
No functional change.
This patch migrates the kdb 'lsmod' command support out of main
kdb code into its own file under kernel/module. In addition to
the above, a minor style warning i.e. missing a blank line after
declarations, was resolved too. The new file was added to
MAINTAINERS.
Signed-off-by: Aaron Tomlin <[email protected]>
---
MAINTAINERS | 1 +
include/linux/kdb.h | 1 +
kernel/debug/kdb/kdb_main.c | 49 ---------------------------------
kernel/module/Makefile | 1 +
kernel/module/kdb.c | 55 +++++++++++++++++++++++++++++++++++++
kernel/module/main.c | 4 ---
6 files changed, 58 insertions(+), 53 deletions(-)
create mode 100644 kernel/module/kdb.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 195cf1ac2ee8..40c717f93c1a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10689,6 +10689,7 @@ F: drivers/tty/serial/kgdboc.c
F: include/linux/kdb.h
F: include/linux/kgdb.h
F: kernel/debug/
+F: kernel/module/kdb.c
KHADAS MCU MFD DRIVER
M: Neil Armstrong <[email protected]>
diff --git a/include/linux/kdb.h b/include/linux/kdb.h
index ea0f5e580fac..07dfb6a20a1c 100644
--- a/include/linux/kdb.h
+++ b/include/linux/kdb.h
@@ -222,5 +222,6 @@ enum {
extern int kdbgetintenv(const char *, int *);
extern int kdb_set(int, const char **);
+int kdb_lsmod(int argc, const char **argv);
#endif /* !_KDB_H */
diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index 0852a537dad4..f3a30cd5037f 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -26,7 +26,6 @@
#include <linux/utsname.h>
#include <linux/vmalloc.h>
#include <linux/atomic.h>
-#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/mm.h>
#include <linux/init.h>
@@ -2004,54 +2003,6 @@ static int kdb_ef(int argc, const char **argv)
return 0;
}
-#if defined(CONFIG_MODULES)
-/*
- * kdb_lsmod - This function implements the 'lsmod' command. Lists
- * currently loaded kernel modules.
- * Mostly taken from userland lsmod.
- */
-static int kdb_lsmod(int argc, const char **argv)
-{
- struct module *mod;
-
- if (argc != 0)
- return KDB_ARGCOUNT;
-
- kdb_printf("Module Size modstruct Used by\n");
- list_for_each_entry(mod, kdb_modules, list) {
- if (mod->state == MODULE_STATE_UNFORMED)
- continue;
-
- kdb_printf("%-20s%8u 0x%px ", mod->name,
- mod->core_layout.size, (void *)mod);
-#ifdef CONFIG_MODULE_UNLOAD
- kdb_printf("%4d ", module_refcount(mod));
-#endif
- if (mod->state == MODULE_STATE_GOING)
- kdb_printf(" (Unloading)");
- else if (mod->state == MODULE_STATE_COMING)
- kdb_printf(" (Loading)");
- else
- kdb_printf(" (Live)");
- kdb_printf(" 0x%px", mod->core_layout.base);
-
-#ifdef CONFIG_MODULE_UNLOAD
- {
- struct module_use *use;
- kdb_printf(" [ ");
- list_for_each_entry(use, &mod->source_list,
- source_list)
- kdb_printf("%s ", use->target->name);
- kdb_printf("]\n");
- }
-#endif
- }
-
- return 0;
-}
-
-#endif /* CONFIG_MODULES */
-
/*
* kdb_env - This function implements the 'env' command. Display the
* current environment variables.
diff --git a/kernel/module/Makefile b/kernel/module/Makefile
index cf8dcdc6b55f..88f5cdcdb067 100644
--- a/kernel/module/Makefile
+++ b/kernel/module/Makefile
@@ -17,3 +17,4 @@ obj-$(CONFIG_DEBUG_KMEMLEAK) += debug_kmemleak.o
obj-$(CONFIG_KALLSYMS) += kallsyms.o
obj-$(CONFIG_PROC_FS) += procfs.o
obj-$(CONFIG_SYSFS) += sysfs.o
+obj-$(CONFIG_KGDB_KDB) += kdb.o
diff --git a/kernel/module/kdb.c b/kernel/module/kdb.c
new file mode 100644
index 000000000000..60baeebea3e0
--- /dev/null
+++ b/kernel/module/kdb.c
@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Module kdb support
+ *
+ * Copyright (C) 2010 Jason Wessel
+ */
+
+#include <linux/module.h>
+#include <linux/kdb.h>
+#include "internal.h"
+
+/*
+ * kdb_lsmod - This function implements the 'lsmod' command. Lists
+ * currently loaded kernel modules.
+ * Mostly taken from userland lsmod.
+ */
+int kdb_lsmod(int argc, const char **argv)
+{
+ struct module *mod;
+
+ if (argc != 0)
+ return KDB_ARGCOUNT;
+
+ kdb_printf("Module Size modstruct Used by\n");
+ list_for_each_entry(mod, &modules, list) {
+ if (mod->state == MODULE_STATE_UNFORMED)
+ continue;
+
+ kdb_printf("%-20s%8u 0x%px ", mod->name,
+ mod->core_layout.size, (void *)mod);
+#ifdef CONFIG_MODULE_UNLOAD
+ kdb_printf("%4d ", module_refcount(mod));
+#endif
+ if (mod->state == MODULE_STATE_GOING)
+ kdb_printf(" (Unloading)");
+ else if (mod->state == MODULE_STATE_COMING)
+ kdb_printf(" (Loading)");
+ else
+ kdb_printf(" (Live)");
+ kdb_printf(" 0x%px", mod->core_layout.base);
+
+#ifdef CONFIG_MODULE_UNLOAD
+ {
+ struct module_use *use;
+ kdb_printf(" [ ");
+ list_for_each_entry(use, &mod->source_list,
+ source_list)
+ kdb_printf("%s ", use->target->name);
+ kdb_printf("]\n");
+ }
+#endif
+ }
+
+ return 0;
+}
diff --git a/kernel/module/main.c b/kernel/module/main.c
index b8a59b5c3e3a..bcc4f7a82649 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -108,10 +108,6 @@ static void mod_update_bounds(struct module *mod)
__mod_update_bounds(mod->init_layout.base, mod->init_layout.size);
}
-#ifdef CONFIG_KGDB_KDB
-struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
-#endif /* CONFIG_KGDB_KDB */
-
static void module_assert_mutex_or_preempt(void)
{
#ifdef CONFIG_LOCKDEP
--
2.34.1