Module name has a limited length, but currently the build system
allows the build finishing even if the module name is too long.
CC /root/kprobe_example/abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz.mod.o
/root/kprobe_example/abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz.mod.c:9:2:
warning: initializer-string for array of chars is too long [enabled by default]
.name = KBUILD_MODNAME,
^
but it's merely a warning.
This patch adds the check of the module name length in modpost and stops
the build properly.
Signed-off-by: Wanlong Gao <[email protected]>
---
scripts/mod/modpost.c | 29 ++++++++++++++++++++++++-----
1 file changed, 24 insertions(+), 5 deletions(-)
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 30d752a..cb16985 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -47,6 +47,12 @@ enum export {
export_unused_gpl, export_gpl_future, export_unknown
};
+/* In kernel, this size is defined in linux/module.h;
+ * here we use Elf_Addr instead of long for covering cross-compile
+ */
+
+#define MODULE_NAME_LEN (64 - sizeof(Elf_Addr))
+
#define PRINTF __attribute__ ((format (printf, 1, 2)))
PRINTF void fatal(const char *fmt, ...)
@@ -2116,6 +2122,23 @@ static void check_exports(struct module *mod)
}
}
+static int check_modname_len(struct module *mod)
+{
+ const char *mod_name;
+
+ mod_name = strrchr(mod->name, '/');
+ if (mod_name == NULL)
+ mod_name = mod->name;
+ else
+ mod_name++;
+ if (strlen(mod_name) >= MODULE_NAME_LEN) {
+ merror("module name is too long [%s.ko]\n", mod->name);
+ return 1;
+ }
+
+ return 0;
+}
+
/**
* Header for the generated file
**/
@@ -2154,11 +2177,6 @@ static void add_staging_flag(struct buffer *b, const char *name)
buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
}
-/* In kernel, this size is defined in linux/module.h;
- * here we use Elf_Addr instead of long for covering cross-compile
- */
-#define MODULE_NAME_LEN (64 - sizeof(Elf_Addr))
-
/**
* Record CRCs for unresolved symbols
**/
@@ -2489,6 +2507,7 @@ int main(int argc, char **argv)
buf.pos = 0;
+ err |= check_modname_len(mod);
add_header(&buf, mod);
add_intree_flag(&buf, !external_module);
add_staging_flag(&buf, mod->name);
--
2.9.4
+++ Wanlong Gao [30/06/17 22:07 +0800]:
>Module name has a limited length, but currently the build system
>allows the build finishing even if the module name is too long.
>
> CC /root/kprobe_example/abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz.mod.o
> /root/kprobe_example/abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz.mod.c:9:2:
> warning: initializer-string for array of chars is too long [enabled by default]
> .name = KBUILD_MODNAME,
> ^
>
>but it's merely a warning.
>
>This patch adds the check of the module name length in modpost and stops
>the build properly.
>
>Signed-off-by: Wanlong Gao <[email protected]>
I have this patch queued up to be applied right after the current
merge window. Thanks!
Jessica
> scripts/mod/modpost.c | 29 ++++++++++++++++++++++++-----
> 1 file changed, 24 insertions(+), 5 deletions(-)
>
>diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
>index 30d752a..cb16985 100644
>--- a/scripts/mod/modpost.c
>+++ b/scripts/mod/modpost.c
>@@ -47,6 +47,12 @@ enum export {
> export_unused_gpl, export_gpl_future, export_unknown
> };
>
>+/* In kernel, this size is defined in linux/module.h;
>+ * here we use Elf_Addr instead of long for covering cross-compile
>+ */
>+
>+#define MODULE_NAME_LEN (64 - sizeof(Elf_Addr))
>+
> #define PRINTF __attribute__ ((format (printf, 1, 2)))
>
> PRINTF void fatal(const char *fmt, ...)
>@@ -2116,6 +2122,23 @@ static void check_exports(struct module *mod)
> }
> }
>
>+static int check_modname_len(struct module *mod)
>+{
>+ const char *mod_name;
>+
>+ mod_name = strrchr(mod->name, '/');
>+ if (mod_name == NULL)
>+ mod_name = mod->name;
>+ else
>+ mod_name++;
>+ if (strlen(mod_name) >= MODULE_NAME_LEN) {
>+ merror("module name is too long [%s.ko]\n", mod->name);
>+ return 1;
>+ }
>+
>+ return 0;
>+}
>+
> /**
> * Header for the generated file
> **/
>@@ -2154,11 +2177,6 @@ static void add_staging_flag(struct buffer *b, const char *name)
> buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
> }
>
>-/* In kernel, this size is defined in linux/module.h;
>- * here we use Elf_Addr instead of long for covering cross-compile
>- */
>-#define MODULE_NAME_LEN (64 - sizeof(Elf_Addr))
>-
> /**
> * Record CRCs for unresolved symbols
> **/
>@@ -2489,6 +2507,7 @@ int main(int argc, char **argv)
>
> buf.pos = 0;
>
>+ err |= check_modname_len(mod);
> add_header(&buf, mod);
> add_intree_flag(&buf, !external_module);
> add_staging_flag(&buf, mod->name);
>--
>2.9.4
>