The commit "consolidate cond_syscall and SYSCALL_ALIAS declarations"
broke the build on blackfin and metag due to the following code:
#ifndef SYMBOL_NAME
#ifdef CONFIG_SYMBOL_PREFIX
#define SYMBOL_NAME(x) CONFIG_SYMBOL_PREFIX ## x
#else
#define SYMBOL_NAME(x) x
#endif
#endif
#define __SYMBOL_NAME(x) __stringify(SYMBOL_NAME(x))
__stringify literally stringifies CONFIG_SYMBOL_PREFIX ##x, so you get
lines like this in the assembly output:
.weak CONFIG_SYMBOL_PREFIXsys_quotactl
.set
CONFIG_SYMBOL_PREFIXsys_quotactl,CONFIG_SYMBOL_PREFIXsys_ni_syscall
This is fixed by defining SYMBOL_PREFIX from the command line for c
files in addition to assembly for architectures that set
CONFIG_SYMBOL_PREFIX (scripts/Makefile.lib), and defining __SYMBOL_NAME
as:
#define __SYMBOL_NAME(x) __stringify(SYMBOL_PREFIX) #x
We first have to ensure SYMBOL_PREFIX is defined (which avoids polluting
the command lines for architectures that don't use symbol prefixes).
Also the definition of SYMBOL_PREFIX in <linux/kernel.h> is removed as
it conflicts, isn't used anywhere, and is defined as a string so differs
from the assembly definition.
Signed-off-by: James Hogan <[email protected]>
---
This is just one possible way of fixing it. It felt the cleanest out of
the ways I tried, but feel free to suggest something better!
include/linux/kernel.h | 7 -------
include/linux/linkage.h | 12 +++++-------
scripts/Makefile.lib | 1 +
3 files changed, 6 insertions(+), 14 deletions(-)
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 80d3687..e13e992 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -723,13 +723,6 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
/* Trap pasters of __FUNCTION__ at compile-time */
#define __FUNCTION__ (__func__)
-/* This helps us to avoid #ifdef CONFIG_SYMBOL_PREFIX */
-#ifdef CONFIG_SYMBOL_PREFIX
-#define SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
-#else
-#define SYMBOL_PREFIX ""
-#endif
-
/* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
# define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
diff --git a/include/linux/linkage.h b/include/linux/linkage.h
index 829d66c..acb869b 100644
--- a/include/linux/linkage.h
+++ b/include/linux/linkage.h
@@ -15,14 +15,12 @@
#define asmlinkage CPP_ASMLINKAGE
#endif
-#ifndef SYMBOL_NAME
-#ifdef CONFIG_SYMBOL_PREFIX
-#define SYMBOL_NAME(x) CONFIG_SYMBOL_PREFIX ## x
-#else
-#define SYMBOL_NAME(x) x
-#endif
+/* This helps us to avoid #ifdef SYMBOL_PREFIX */
+#ifndef SYMBOL_PREFIX
+#define SYMBOL_PREFIX
#endif
-#define __SYMBOL_NAME(x) __stringify(SYMBOL_NAME(x))
+
+#define __SYMBOL_NAME(x) __stringify(SYMBOL_PREFIX) #x
#ifndef cond_syscall
#define cond_syscall(x) asm(".weak\t" __SYMBOL_NAME(x) \
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 07125e6..f1cce6a 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -123,6 +123,7 @@ ifdef CONFIG_SYMBOL_PREFIX
_sym_flags = -DSYMBOL_PREFIX=$(patsubst "%",%,$(CONFIG_SYMBOL_PREFIX))
_cpp_flags += $(_sym_flags)
_a_flags += $(_sym_flags)
+_c_flags += $(_sym_flags)
endif
--
1.8.1.2
James Hogan <[email protected]> writes:
> The commit "consolidate cond_syscall and SYSCALL_ALIAS declarations"
> broke the build on blackfin and metag due to the following code:
>
> #ifndef SYMBOL_NAME
> #ifdef CONFIG_SYMBOL_PREFIX
> #define SYMBOL_NAME(x) CONFIG_SYMBOL_PREFIX ## x
> #else
> #define SYMBOL_NAME(x) x
> #endif
> #endif
> #define __SYMBOL_NAME(x) __stringify(SYMBOL_NAME(x))
>
> __stringify literally stringifies CONFIG_SYMBOL_PREFIX ##x, so you get
> lines like this in the assembly output:
>
> .weak CONFIG_SYMBOL_PREFIXsys_quotactl
> .set
> CONFIG_SYMBOL_PREFIXsys_quotactl,CONFIG_SYMBOL_PREFIXsys_ni_syscall
>
> This is fixed by defining SYMBOL_PREFIX from the command line for c
> files in addition to assembly for architectures that set
> CONFIG_SYMBOL_PREFIX (scripts/Makefile.lib), and defining __SYMBOL_NAME
> as:
>
> #define __SYMBOL_NAME(x) __stringify(SYMBOL_PREFIX) #x
>
> We first have to ensure SYMBOL_PREFIX is defined (which avoids polluting
> the command lines for architectures that don't use symbol prefixes).
> Also the definition of SYMBOL_PREFIX in <linux/kernel.h> is removed as
> it conflicts, isn't used anywhere, and is defined as a string so differs
> from the assembly definition.
So now, if CONFIG_SYMBOL_PREFIX, SYMBOL_PREFIX is defined on the cmdline
as a string. Otherwise it's empty (not the empty string?):
> +/* This helps us to avoid #ifdef SYMBOL_PREFIX */
> +#ifndef SYMBOL_PREFIX
> +#define SYMBOL_PREFIX
> #endif
> -#define __SYMBOL_NAME(x) __stringify(SYMBOL_NAME(x))
> +
> +#define __SYMBOL_NAME(x) __stringify(SYMBOL_PREFIX) #x
And why are you __stringify()ing a string?
> #ifndef cond_syscall
> #define cond_syscall(x) asm(".weak\t" __SYMBOL_NAME(x) \
> diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
> index 07125e6..f1cce6a 100644
> --- a/scripts/Makefile.lib
> +++ b/scripts/Makefile.lib
> @@ -123,6 +123,7 @@ ifdef CONFIG_SYMBOL_PREFIX
> _sym_flags = -DSYMBOL_PREFIX=$(patsubst "%",%,$(CONFIG_SYMBOL_PREFIX))
> _cpp_flags += $(_sym_flags)
> _a_flags += $(_sym_flags)
> +_c_flags += $(_sym_flags)
> endif
Confused,
Rusty.
Hi Rusty,
On 08/03/13 00:03, Rusty Russell wrote:
> James Hogan <[email protected]> writes:
>> Also the definition of SYMBOL_PREFIX in <linux/kernel.h> is removed as
>> it conflicts, isn't used anywhere, and is defined as a string so differs
>> from the assembly definition.
>
> So now, if CONFIG_SYMBOL_PREFIX, SYMBOL_PREFIX is defined on the cmdline
> as a string. Otherwise it's empty (not the empty string?):
No, SYMBOL_PREFIX is now defined as a non-string, same as asm files, but
the now unused definition in linux/kernel.h did define it as a string as
it used CONFIG_SYMBOL_PREFIX which is a string. When I said "and is
defined as a string" I was referring to the one in linux/kernel.h that
this removes.
Does that make sense? It's all a bit messy unfortunately (hence RFC).
Cheers
James
James Hogan <[email protected]> writes:
> Hi Rusty,
>
> On 08/03/13 00:03, Rusty Russell wrote:
>> James Hogan <[email protected]> writes:
>>> Also the definition of SYMBOL_PREFIX in <linux/kernel.h> is removed as
>>> it conflicts, isn't used anywhere, and is defined as a string so differs
>>> from the assembly definition.
>>
>> So now, if CONFIG_SYMBOL_PREFIX, SYMBOL_PREFIX is defined on the cmdline
>> as a string. Otherwise it's empty (not the empty string?):
>
> No, SYMBOL_PREFIX is now defined as a non-string, same as asm files
Ah, I misread this. It's stripping the quotes, not adding them:
_sym_flags = -DSYMBOL_PREFIX=$(patsubst "%",%,$(CONFIG_SYMBOL_PREFIX))
> Does that make sense? It's all a bit messy unfortunately (hence RFC).
Yes, let's clear it up once and for all. Does this work?
CONFIG_SYMBOL_PREFIX: cleanup.
We have CONFIG_SYMBOL_PREFIX, which three archs define to the string
"_". But Al Viro broke this in "consolidate cond_syscall and
SYSCALL_ALIAS declarations", and he's not the first to do so.
Using CONFIG_SYMBOL_PREFIX is awkward, since we usually just want to
prefix it so something. So various places define helpers which are
defined to nothing if CONFIG_SYMBOL_PREFIX isn't set:
1) include/asm-generic/unistd.h defines __SYMBOL_PREFIX.
2) include/asm-generic/vmlinux.lds.h defines VMLINUX_SYMBOL(sym)
3) include/linux/export.h defines MODULE_SYMBOL_PREFIX.
4) include/linux/kernel.h defines SYMBOL_PREFIX (which differs from #7)
5) kernel/modsign_certificate.S defines ASM_SYMBOL(sym)
6) scripts/modpost.c defines MODULE_SYMBOL_PREFIX
7) scripts/Makefile.lib defines SYMBOL_PREFIX on the commandline if
CONFIG_SYMBOL_PREFIX is set, so that we have a non-string version
for pasting.
(arch/h8300/include/asm/linkage.h defines SYMBOL_NAME(), too).
Let's solve this properly:
1) No more generic prefix, just CONFIG_SYMBOL_PREFIX_UNDERSCORE.
2) Make linux/export.h usable from asm.
3) Define VMLINUX_SYMBOL, VMLINUX_SYMBOL_NAME and VMLINUX_SYMBOL_PREFIX_STR.
4) Make everyone use them.
Signed-off-by: Rusty Russell <[email protected]>
diff --git a/Makefile b/Makefile
index 5bd9f77..b2e3e1b 100644
--- a/Makefile
+++ b/Makefile
@@ -1398,7 +1398,7 @@ quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN $(wildcard $(rm-files))
# Run depmod only if we have System.map and depmod is executable
quiet_cmd_depmod = DEPMOD $(KERNELRELEASE)
cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
- $(KERNELRELEASE) "$(patsubst "%",%,$(CONFIG_SYMBOL_PREFIX))"
+ $(KERNELRELEASE) "$(patsubst y,_,$(CONFIG_SYMBOL_PREFIX_UNDERSCORE))"
# Create temporary dir for module support files
# clean it up only when building all modules
diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig
index 600494c..cd0f7c7 100644
--- a/arch/blackfin/Kconfig
+++ b/arch/blackfin/Kconfig
@@ -1,6 +1,5 @@
-config SYMBOL_PREFIX
- string
- default "_"
+config SYMBOL_PREFIX_UNDERSCORE
+ def_bool y
config MMU
def_bool n
diff --git a/arch/h8300/Kconfig b/arch/h8300/Kconfig
index ae8551e..ec9924d 100644
--- a/arch/h8300/Kconfig
+++ b/arch/h8300/Kconfig
@@ -13,9 +13,8 @@ config H8300
select OLD_SIGSUSPEND3
select OLD_SIGACTION
-config SYMBOL_PREFIX
- string
- default "_"
+config SYMBOL_PREFIX_UNDERSCORE
+ def_bool y
config MMU
bool
diff --git a/arch/metag/Kconfig b/arch/metag/Kconfig
index afc8973..e8719b4 100644
--- a/arch/metag/Kconfig
+++ b/arch/metag/Kconfig
@@ -1,6 +1,5 @@
-config SYMBOL_PREFIX
- string
- default "_"
+config SYMBOL_PREFIX_UNDERSCORE
+ def_bool y
config METAG
def_bool y
diff --git a/drivers/mtd/chips/gen_probe.c b/drivers/mtd/chips/gen_probe.c
index 3b9a284..00d20ad 100644
--- a/drivers/mtd/chips/gen_probe.c
+++ b/drivers/mtd/chips/gen_probe.c
@@ -204,14 +204,14 @@ static inline struct mtd_info *cfi_cmdset_unknown(struct map_info *map,
struct cfi_private *cfi = map->fldrv_priv;
__u16 type = primary?cfi->cfiq->P_ID:cfi->cfiq->A_ID;
#ifdef CONFIG_MODULES
- char probename[16+sizeof(MODULE_SYMBOL_PREFIX)];
+ char probename[16+sizeof(VMLINUX_SYMBOL_PREFIX_STR)];
cfi_cmdset_fn_t *probe_function;
- sprintf(probename, MODULE_SYMBOL_PREFIX "cfi_cmdset_%4.4X", type);
+ sprintf(probename, VMLINUX_SYMBOL_PREFIX_STR "cfi_cmdset_%4.4X", type);
probe_function = __symbol_get(probename);
if (!probe_function) {
- request_module(probename + sizeof(MODULE_SYMBOL_PREFIX) - 1);
+ request_module(probename + sizeof(VMLINUX_SYMBOL_PREFIX_STR)-1);
probe_function = __symbol_get(probename);
}
diff --git a/include/asm-generic/unistd.h b/include/asm-generic/unistd.h
index 4077b5d..80122d4 100644
--- a/include/asm-generic/unistd.h
+++ b/include/asm-generic/unistd.h
@@ -1,4 +1,5 @@
#include <uapi/asm-generic/unistd.h>
+#include <linux/export.h>
/*
* These are required system calls, we should
@@ -17,12 +18,7 @@
* but it doesn't work on all toolchains, so we just do it by hand
*/
#ifndef cond_syscall
-#ifdef CONFIG_SYMBOL_PREFIX
-#define __SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
-#else
-#define __SYMBOL_PREFIX
-#endif
-#define cond_syscall(x) asm(".weak\t" __SYMBOL_PREFIX #x "\n\t" \
- ".set\t" __SYMBOL_PREFIX #x "," \
- __SYMBOL_PREFIX "sys_ni_syscall")
+#define cond_syscall(x) asm(".weak\t" SYMBOL_NAME_STR(x) "\n\t" \
+ ".set\t" SYMBOL_NAME_STR(x) "," \
+ SYMBOL_NAME_STR(sys_ni_syscall))
#endif
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index afa12c7..eb58d2d 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -52,13 +52,7 @@
#define LOAD_OFFSET 0
#endif
-#ifndef SYMBOL_PREFIX
-#define VMLINUX_SYMBOL(sym) sym
-#else
-#define PASTE2(x,y) x##y
-#define PASTE(x,y) PASTE2(x,y)
-#define VMLINUX_SYMBOL(sym) PASTE(SYMBOL_PREFIX, sym)
-#endif
+#include <linux/export.h>
/* Align . to a 8 byte boundary equals to maximum function alignment. */
#define ALIGN_FUNCTION() . = ALIGN(8)
diff --git a/include/linux/export.h b/include/linux/export.h
index 696c0f4..c3c1cfc 100644
--- a/include/linux/export.h
+++ b/include/linux/export.h
@@ -7,15 +7,27 @@
*
* If you feel the need to add #include <linux/foo.h> to this file
* then you are doing something wrong and should go away silently.
+ *
+ * If you think the above arrogance just encourages more people to add
+ * random crap to this file, you're not alone.
*/
/* Some toolchains use a `_' prefix for all user symbols. */
-#ifdef CONFIG_SYMBOL_PREFIX
-#define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
+#ifdef CONFIG_SYMBOL_PREFIX_UNDERSCORE
+#define __VMLINUX_SYMBOL(x) _##x
+#define __VMLINUX_SYMBOL_STR(x) "_" #x
+#define VMLINUX_SYMBOL_PREFIX_STR "_"
#else
-#define MODULE_SYMBOL_PREFIX ""
+#define __VMLINUX_SYMBOL(x) x
+#define __VMLINUX_SYMBOL_STR(x) #x
+#define VMLINUX_SYMBOL_PREFIX_STR ""
#endif
+/* Indirect, so macros are expanded before pasting. */
+#define VMLINUX_SYMBOL(x) __VMLINUX_SYMBOL(x)
+#define VMLINUX_SYMBOL_STR(x) __VMLINUX_SYMBOL_STR(x)
+
+#ifndef __ASSEMBLY__
struct kernel_symbol
{
unsigned long value;
@@ -51,7 +63,7 @@ extern struct module __this_module;
__CRC_SYMBOL(sym, sec) \
static const char __kstrtab_##sym[] \
__attribute__((section("__ksymtab_strings"), aligned(1))) \
- = MODULE_SYMBOL_PREFIX #sym; \
+ = VMLINUX_SYMBOL_STR(sym); \
static const struct kernel_symbol __ksymtab_##sym \
__used \
__attribute__((section("___ksymtab" sec "+" #sym), unused)) \
@@ -85,5 +97,6 @@ extern struct module __this_module;
#define EXPORT_UNUSED_SYMBOL_GPL(sym)
#endif /* CONFIG_MODULES */
+#endif /* !__ASSEMBLY__ */
#endif /* _LINUX_EXPORT_H */
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 80d3687..e13e992 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -723,13 +723,6 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
/* Trap pasters of __FUNCTION__ at compile-time */
#define __FUNCTION__ (__func__)
-/* This helps us to avoid #ifdef CONFIG_SYMBOL_PREFIX */
-#ifdef CONFIG_SYMBOL_PREFIX
-#define SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
-#else
-#define SYMBOL_PREFIX ""
-#endif
-
/* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
# define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
diff --git a/include/linux/module.h b/include/linux/module.h
index ead1b57..46f1ea0 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -190,7 +190,7 @@ extern int modules_disabled; /* for sysctl */
/* Get/put a kernel symbol (calls must be symmetric) */
void *__symbol_get(const char *symbol);
void *__symbol_get_gpl(const char *symbol);
-#define symbol_get(x) ((typeof(&x))(__symbol_get(MODULE_SYMBOL_PREFIX #x)))
+#define symbol_get(x) ((typeof(&x))(__symbol_get(VMLINUX_SYMBOL_STR(x))))
/* modules using other modules: kdb wants to see this. */
struct module_use {
@@ -453,7 +453,7 @@ extern void __module_put_and_exit(struct module *mod, long code)
#ifdef CONFIG_MODULE_UNLOAD
unsigned long module_refcount(struct module *mod);
void __symbol_put(const char *symbol);
-#define symbol_put(x) __symbol_put(MODULE_SYMBOL_PREFIX #x)
+#define symbol_put(x) __symbol_put(VMLINUX_SYMBOL_STR(x))
void symbol_put_addr(void *addr);
/* Sometimes we know we already have a refcount, and it's easier not
diff --git a/kernel/modsign_certificate.S b/kernel/modsign_certificate.S
index 246b4c6..4a9a86d 100644
--- a/kernel/modsign_certificate.S
+++ b/kernel/modsign_certificate.S
@@ -1,15 +1,8 @@
-/* SYMBOL_PREFIX defined on commandline from CONFIG_SYMBOL_PREFIX */
-#ifndef SYMBOL_PREFIX
-#define ASM_SYMBOL(sym) sym
-#else
-#define PASTE2(x,y) x##y
-#define PASTE(x,y) PASTE2(x,y)
-#define ASM_SYMBOL(sym) PASTE(SYMBOL_PREFIX, sym)
-#endif
+#include <linux/export.h>
#define GLOBAL(name) \
- .globl ASM_SYMBOL(name); \
- ASM_SYMBOL(name):
+ .globl VMLINUX_SYMBOL(name); \
+ VMLINUX_SYMBOL(name):
.section ".init.data","aw"
diff --git a/kernel/module.c b/kernel/module.c
index 0925c9a..cfd4a3f 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1209,7 +1209,7 @@ static inline int check_modstruct_version(Elf_Shdr *sechdrs,
/* Since this should be found in kernel (which can't be removed),
* no locking is necessary. */
- if (!find_symbol(MODULE_SYMBOL_PREFIX "module_layout", NULL,
+ if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
&crc, true, false))
BUG();
return check_version(sechdrs, versindex, "module_layout", mod, crc,
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 07125e6..a373a1f 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -119,13 +119,6 @@ _c_flags += $(if $(patsubst n%,, \
$(CFLAGS_GCOV))
endif
-ifdef CONFIG_SYMBOL_PREFIX
-_sym_flags = -DSYMBOL_PREFIX=$(patsubst "%",%,$(CONFIG_SYMBOL_PREFIX))
-_cpp_flags += $(_sym_flags)
-_a_flags += $(_sym_flags)
-endif
-
-
# If building the kernel in a separate objtree expand all occurrences
# of -Idir to -I$(srctree)/dir except for absolute paths (starting with '/').
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index 3d569d6..d767681 100644
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -74,9 +74,8 @@ kallsyms()
info KSYM ${2}
local kallsymopt;
- if [ -n "${CONFIG_SYMBOL_PREFIX}" ]; then
- kallsymopt="${kallsymopt} \
- --symbol-prefix=${CONFIG_SYMBOL_PREFIX}"
+ if [ -n "${CONFIG_SYMBOL_PREFIX_UNDERSCORE}" ]; then
+ kallsymopt="${kallsymopt} --symbol-prefix=_"
fi
if [ -n "${CONFIG_KALLSYMS_ALL}" ]; then
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 78b30c1..6985021 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -18,14 +18,7 @@
#include "modpost.h"
#include "../../include/generated/autoconf.h"
#include "../../include/linux/license.h"
-
-/* Some toolchains use a `_' prefix for all user symbols. */
-#ifdef CONFIG_SYMBOL_PREFIX
-#define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
-#else
-#define MODULE_SYMBOL_PREFIX ""
-#endif
-
+#include "../../include/linux/export.h"
/* Are we using CONFIG_MODVERSIONS? */
int modversions = 0;
@@ -562,7 +555,7 @@ static void parse_elf_finish(struct elf_info *info)
static int ignore_undef_symbol(struct elf_info *info, const char *symname)
{
/* ignore __this_module, it will be resolved shortly */
- if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0)
+ if (strcmp(symname, VMLINUX_SYMBOL_STR(__this_module)) == 0)
return 1;
/* ignore global offset table */
if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
@@ -583,8 +576,8 @@ static int ignore_undef_symbol(struct elf_info *info, const char *symname)
return 0;
}
-#define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_"
-#define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
+#define CRC_PFX VMLINUX_SYMBOL_STR(__crc_)
+#define KSYMTAB_PFX VMLINUX_SYMBOL_STR(__ksymtab_)
static void handle_modversions(struct module *mod, struct elf_info *info,
Elf_Sym *sym, const char *symname)
@@ -637,11 +630,11 @@ static void handle_modversions(struct module *mod, struct elf_info *info,
}
#endif
- if (memcmp(symname, MODULE_SYMBOL_PREFIX,
- strlen(MODULE_SYMBOL_PREFIX)) == 0) {
+ if (memcmp(symname, VMLINUX_SYMBOL_PREFIX_STR,
+ strlen(VMLINUX_SYMBOL_PREFIX_STR)) == 0) {
mod->unres =
alloc_symbol(symname +
- strlen(MODULE_SYMBOL_PREFIX),
+ strlen(VMLINUX_SYMBOL_PREFIX_STR),
ELF_ST_BIND(sym->st_info) == STB_WEAK,
mod->unres);
}
@@ -652,9 +645,9 @@ static void handle_modversions(struct module *mod, struct elf_info *info,
sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
export);
}
- if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0)
+ if (strcmp(symname, VMLINUX_SYMBOL_STR(init_module)) == 0)
mod->has_init = 1;
- if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0)
+ if (strcmp(symname, VMLINUX_SYMBOL_STR(cleanup_module)) == 0)
mod->has_cleanup = 1;
break;
}
Hi Rusty,
On Mon, 11 Mar 2013 17:05:17 +1030 Rusty Russell <[email protected]> wrote:
>
> diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig
> index 600494c..cd0f7c7 100644
> --- a/arch/blackfin/Kconfig
> +++ b/arch/blackfin/Kconfig
> @@ -1,6 +1,5 @@
> -config SYMBOL_PREFIX
> - string
> - default "_"
> +config SYMBOL_PREFIX_UNDERSCORE
> + def_bool y
Please, if you are going to do this, just have
config SYMBOL_PREFIX_UNDERSCORE
bool
in one Kconfig file (probably arch/Kconfig) and then select it from the
appropriate architecture Kconfig files. You could even put a help text
on it to explain why a new architecture may need to select it.
--
Cheers,
Stephen Rothwell [email protected]
Stephen Rothwell <[email protected]> writes:
> Hi Rusty,
>
> On Mon, 11 Mar 2013 17:05:17 +1030 Rusty Russell <[email protected]> wrote:
>>
>> diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig
>> index 600494c..cd0f7c7 100644
>> --- a/arch/blackfin/Kconfig
>> +++ b/arch/blackfin/Kconfig
>> @@ -1,6 +1,5 @@
>> -config SYMBOL_PREFIX
>> - string
>> - default "_"
>> +config SYMBOL_PREFIX_UNDERSCORE
>> + def_bool y
>
> Please, if you are going to do this, just have
>
> config SYMBOL_PREFIX_UNDERSCORE
> bool
>
> in one Kconfig file (probably arch/Kconfig) and then select it from the
> appropriate architecture Kconfig files. You could even put a help text
> on it to explain why a new architecture may need to select it.
>
> --
> Cheers,
> Stephen Rothwell [email protected]
OK.
v2: Rename CONFIG_SYMBOL_PREFIX_UNDERSCORE to CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX,
which is defined in arch/Kconfig and selected by the 3 archs which need it.
Subject: CONFIG_SYMBOL_PREFIX: cleanup.
We have CONFIG_SYMBOL_PREFIX, which three archs define to the string
"_". But Al Viro broke this in "consolidate cond_syscall and
SYSCALL_ALIAS declarations", and he's not the first to do so.
Using CONFIG_SYMBOL_PREFIX is awkward, since we usually just want to
prefix it so something. So various places define helpers which are
defined to nothing if CONFIG_SYMBOL_PREFIX isn't set:
1) include/asm-generic/unistd.h defines __SYMBOL_PREFIX.
2) include/asm-generic/vmlinux.lds.h defines VMLINUX_SYMBOL(sym)
3) include/linux/export.h defines MODULE_SYMBOL_PREFIX.
4) include/linux/kernel.h defines SYMBOL_PREFIX (which differs from #7)
5) kernel/modsign_certificate.S defines ASM_SYMBOL(sym)
6) scripts/modpost.c defines MODULE_SYMBOL_PREFIX
7) scripts/Makefile.lib defines SYMBOL_PREFIX on the commandline if
CONFIG_SYMBOL_PREFIX is set, so that we have a non-string version
for pasting.
(arch/h8300/include/asm/linkage.h defines SYMBOL_NAME(), too).
Let's solve this properly:
1) No more generic prefix, just CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX.
2) Make linux/export.h usable from asm.
3) Define VMLINUX_SYMBOL, VMLINUX_SYMBOL_NAME and VMLINUX_SYMBOL_PREFIX_STR.
4) Make everyone use them.
Signed-off-by: Rusty Russell <[email protected]>
diff --git a/Makefile b/Makefile
index a05ea42..9dc948d 100644
--- a/Makefile
+++ b/Makefile
@@ -1398,7 +1398,7 @@ quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN $(wildcard $(rm-files))
# Run depmod only if we have System.map and depmod is executable
quiet_cmd_depmod = DEPMOD $(KERNELRELEASE)
cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
- $(KERNELRELEASE) "$(patsubst "%",%,$(CONFIG_SYMBOL_PREFIX))"
+ $(KERNELRELEASE) "$(patsubst y,_,$(CONFIG_SYMBOL_PREFIX_UNDERSCORE))"
# Create temporary dir for module support files
# clean it up only when building all modules
diff --git a/arch/Kconfig b/arch/Kconfig
index 5a1779c..12ba8f9 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -391,6 +391,12 @@ config MODULES_USE_ELF_REL
Modules only use ELF REL relocations. Modules with ELF RELA
relocations will give an error.
+config HAVE_UNDERSCORE_SYMBOL_PREFIX
+ bool
+ help
+ Some architectures generate an _ in front of C symbols; things like
+ module loading and assembly files need to know about this.
+
#
# ABI hall of shame
#
diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig
index 600494c..314ee6a 100644
--- a/arch/blackfin/Kconfig
+++ b/arch/blackfin/Kconfig
@@ -1,7 +1,3 @@
-config SYMBOL_PREFIX
- string
- default "_"
-
config MMU
def_bool n
@@ -33,6 +29,7 @@ config BLACKFIN
select ARCH_HAVE_CUSTOM_GPIO_H
select ARCH_WANT_OPTIONAL_GPIOLIB
select HAVE_UID16
+ select HAVE_UNDERSCORE_SYMBOL_PREFIX
select HAVE_VIRT_TO_BUS
select ARCH_WANT_IPC_PARSE_VERSION
select HAVE_GENERIC_HARDIRQS
@@ -45,6 +42,7 @@ config BLACKFIN
select HAVE_MOD_ARCH_SPECIFIC
select MODULES_USE_ELF_RELA
+
config GENERIC_CSUM
def_bool y
diff --git a/arch/h8300/Kconfig b/arch/h8300/Kconfig
index ae8551e..ba043e3 100644
--- a/arch/h8300/Kconfig
+++ b/arch/h8300/Kconfig
@@ -12,10 +12,10 @@ config H8300
select MODULES_USE_ELF_RELA
select OLD_SIGSUSPEND3
select OLD_SIGACTION
+ select HAVE_UNDERSCORE_SYMBOL_PREFIX
-config SYMBOL_PREFIX
- string
- default "_"
+config SYMBOL_PREFIX_UNDERSCORE
+ def_bool y
config MMU
bool
diff --git a/arch/metag/Kconfig b/arch/metag/Kconfig
index afc8973..88272ce 100644
--- a/arch/metag/Kconfig
+++ b/arch/metag/Kconfig
@@ -1,6 +1,5 @@
-config SYMBOL_PREFIX
- string
- default "_"
+config SYMBOL_PREFIX_UNDERSCORE
+ def_bool y
config METAG
def_bool y
@@ -27,6 +26,7 @@ config METAG
select HAVE_MOD_ARCH_SPECIFIC
select HAVE_PERF_EVENTS
select HAVE_SYSCALL_TRACEPOINTS
+ select HAVE_UNDERSCORE_SYMBOL_PREFIX
select IRQ_DOMAIN
select MODULES_USE_ELF_RELA
select OF
diff --git a/drivers/mtd/chips/gen_probe.c b/drivers/mtd/chips/gen_probe.c
index 3b9a284..00d20ad 100644
--- a/drivers/mtd/chips/gen_probe.c
+++ b/drivers/mtd/chips/gen_probe.c
@@ -204,14 +204,14 @@ static inline struct mtd_info *cfi_cmdset_unknown(struct map_info *map,
struct cfi_private *cfi = map->fldrv_priv;
__u16 type = primary?cfi->cfiq->P_ID:cfi->cfiq->A_ID;
#ifdef CONFIG_MODULES
- char probename[16+sizeof(MODULE_SYMBOL_PREFIX)];
+ char probename[16+sizeof(VMLINUX_SYMBOL_PREFIX_STR)];
cfi_cmdset_fn_t *probe_function;
- sprintf(probename, MODULE_SYMBOL_PREFIX "cfi_cmdset_%4.4X", type);
+ sprintf(probename, VMLINUX_SYMBOL_PREFIX_STR "cfi_cmdset_%4.4X", type);
probe_function = __symbol_get(probename);
if (!probe_function) {
- request_module(probename + sizeof(MODULE_SYMBOL_PREFIX) - 1);
+ request_module(probename + sizeof(VMLINUX_SYMBOL_PREFIX_STR)-1);
probe_function = __symbol_get(probename);
}
diff --git a/include/asm-generic/unistd.h b/include/asm-generic/unistd.h
index 4077b5d..80122d4 100644
--- a/include/asm-generic/unistd.h
+++ b/include/asm-generic/unistd.h
@@ -1,4 +1,5 @@
#include <uapi/asm-generic/unistd.h>
+#include <linux/export.h>
/*
* These are required system calls, we should
@@ -17,12 +18,7 @@
* but it doesn't work on all toolchains, so we just do it by hand
*/
#ifndef cond_syscall
-#ifdef CONFIG_SYMBOL_PREFIX
-#define __SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
-#else
-#define __SYMBOL_PREFIX
-#endif
-#define cond_syscall(x) asm(".weak\t" __SYMBOL_PREFIX #x "\n\t" \
- ".set\t" __SYMBOL_PREFIX #x "," \
- __SYMBOL_PREFIX "sys_ni_syscall")
+#define cond_syscall(x) asm(".weak\t" SYMBOL_NAME_STR(x) "\n\t" \
+ ".set\t" SYMBOL_NAME_STR(x) "," \
+ SYMBOL_NAME_STR(sys_ni_syscall))
#endif
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index afa12c7..eb58d2d 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -52,13 +52,7 @@
#define LOAD_OFFSET 0
#endif
-#ifndef SYMBOL_PREFIX
-#define VMLINUX_SYMBOL(sym) sym
-#else
-#define PASTE2(x,y) x##y
-#define PASTE(x,y) PASTE2(x,y)
-#define VMLINUX_SYMBOL(sym) PASTE(SYMBOL_PREFIX, sym)
-#endif
+#include <linux/export.h>
/* Align . to a 8 byte boundary equals to maximum function alignment. */
#define ALIGN_FUNCTION() . = ALIGN(8)
diff --git a/include/linux/export.h b/include/linux/export.h
index 696c0f4..0080e93 100644
--- a/include/linux/export.h
+++ b/include/linux/export.h
@@ -7,15 +7,27 @@
*
* If you feel the need to add #include <linux/foo.h> to this file
* then you are doing something wrong and should go away silently.
+ *
+ * If you think the above arrogance just encourages more people to add
+ * random crap to this file, you're not alone.
*/
/* Some toolchains use a `_' prefix for all user symbols. */
-#ifdef CONFIG_SYMBOL_PREFIX
-#define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
+#ifdef CONFIG_SYMBOL_PREFIX_UNDERSCORE
+#define __VMLINUX_SYMBOL(x) _##x
+#define __VMLINUX_SYMBOL_STR(x) "_" #x
+#define VMLINUX_SYMBOL_PREFIX_STR "_"
#else
-#define MODULE_SYMBOL_PREFIX ""
+#define __VMLINUX_SYMBOL(x) x
+#define __VMLINUX_SYMBOL_STR(x) #x
+#define VMLINUX_SYMBOL_PREFIX_STR ""
#endif
+/* Indirect, so macros are expanded before pasting. */
+#define VMLINUX_SYMBOL(x) __VMLINUX_SYMBOL(x)
+#define VMLINUX_SYMBOL_STR(x) __VMLINUX_SYMBOL_STR(x)
+
+#ifndef __ASSEMBLY__
struct kernel_symbol
{
unsigned long value;
@@ -51,7 +63,7 @@ extern struct module __this_module;
__CRC_SYMBOL(sym, sec) \
static const char __kstrtab_##sym[] \
__attribute__((section("__ksymtab_strings"), aligned(1))) \
- = MODULE_SYMBOL_PREFIX #sym; \
+ = VMLINUX_SYMBOL_STR(sym); \
static const struct kernel_symbol __ksymtab_##sym \
__used \
__attribute__((section("___ksymtab" sec "+" #sym), unused)) \
@@ -85,5 +97,6 @@ extern struct module __this_module;
#define EXPORT_UNUSED_SYMBOL_GPL(sym)
#endif /* CONFIG_MODULES */
+#endif /* !__ASSEMBLY__ */
#endif /* _LINUX_EXPORT_H */
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 80d3687..e13e992 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -723,13 +723,6 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
/* Trap pasters of __FUNCTION__ at compile-time */
#define __FUNCTION__ (__func__)
-/* This helps us to avoid #ifdef CONFIG_SYMBOL_PREFIX */
-#ifdef CONFIG_SYMBOL_PREFIX
-#define SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
-#else
-#define SYMBOL_PREFIX ""
-#endif
-
/* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
# define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
diff --git a/include/linux/module.h b/include/linux/module.h
index ead1b57..46f1ea0 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -190,7 +190,7 @@ extern int modules_disabled; /* for sysctl */
/* Get/put a kernel symbol (calls must be symmetric) */
void *__symbol_get(const char *symbol);
void *__symbol_get_gpl(const char *symbol);
-#define symbol_get(x) ((typeof(&x))(__symbol_get(MODULE_SYMBOL_PREFIX #x)))
+#define symbol_get(x) ((typeof(&x))(__symbol_get(VMLINUX_SYMBOL_STR(x))))
/* modules using other modules: kdb wants to see this. */
struct module_use {
@@ -453,7 +453,7 @@ extern void __module_put_and_exit(struct module *mod, long code)
#ifdef CONFIG_MODULE_UNLOAD
unsigned long module_refcount(struct module *mod);
void __symbol_put(const char *symbol);
-#define symbol_put(x) __symbol_put(MODULE_SYMBOL_PREFIX #x)
+#define symbol_put(x) __symbol_put(VMLINUX_SYMBOL_STR(x))
void symbol_put_addr(void *addr);
/* Sometimes we know we already have a refcount, and it's easier not
diff --git a/kernel/modsign_certificate.S b/kernel/modsign_certificate.S
index 246b4c6..4a9a86d 100644
--- a/kernel/modsign_certificate.S
+++ b/kernel/modsign_certificate.S
@@ -1,15 +1,8 @@
-/* SYMBOL_PREFIX defined on commandline from CONFIG_SYMBOL_PREFIX */
-#ifndef SYMBOL_PREFIX
-#define ASM_SYMBOL(sym) sym
-#else
-#define PASTE2(x,y) x##y
-#define PASTE(x,y) PASTE2(x,y)
-#define ASM_SYMBOL(sym) PASTE(SYMBOL_PREFIX, sym)
-#endif
+#include <linux/export.h>
#define GLOBAL(name) \
- .globl ASM_SYMBOL(name); \
- ASM_SYMBOL(name):
+ .globl VMLINUX_SYMBOL(name); \
+ VMLINUX_SYMBOL(name):
.section ".init.data","aw"
diff --git a/kernel/module.c b/kernel/module.c
index 0925c9a..cfd4a3f 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1209,7 +1209,7 @@ static inline int check_modstruct_version(Elf_Shdr *sechdrs,
/* Since this should be found in kernel (which can't be removed),
* no locking is necessary. */
- if (!find_symbol(MODULE_SYMBOL_PREFIX "module_layout", NULL,
+ if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
&crc, true, false))
BUG();
return check_version(sechdrs, versindex, "module_layout", mod, crc,
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 07125e6..a373a1f 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -119,13 +119,6 @@ _c_flags += $(if $(patsubst n%,, \
$(CFLAGS_GCOV))
endif
-ifdef CONFIG_SYMBOL_PREFIX
-_sym_flags = -DSYMBOL_PREFIX=$(patsubst "%",%,$(CONFIG_SYMBOL_PREFIX))
-_cpp_flags += $(_sym_flags)
-_a_flags += $(_sym_flags)
-endif
-
-
# If building the kernel in a separate objtree expand all occurrences
# of -Idir to -I$(srctree)/dir except for absolute paths (starting with '/').
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index 3d569d6..d767681 100644
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -74,9 +74,8 @@ kallsyms()
info KSYM ${2}
local kallsymopt;
- if [ -n "${CONFIG_SYMBOL_PREFIX}" ]; then
- kallsymopt="${kallsymopt} \
- --symbol-prefix=${CONFIG_SYMBOL_PREFIX}"
+ if [ -n "${CONFIG_SYMBOL_PREFIX_UNDERSCORE}" ]; then
+ kallsymopt="${kallsymopt} --symbol-prefix=_"
fi
if [ -n "${CONFIG_KALLSYMS_ALL}" ]; then
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 78b30c1..6985021 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -18,14 +18,7 @@
#include "modpost.h"
#include "../../include/generated/autoconf.h"
#include "../../include/linux/license.h"
-
-/* Some toolchains use a `_' prefix for all user symbols. */
-#ifdef CONFIG_SYMBOL_PREFIX
-#define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
-#else
-#define MODULE_SYMBOL_PREFIX ""
-#endif
-
+#include "../../include/linux/export.h"
/* Are we using CONFIG_MODVERSIONS? */
int modversions = 0;
@@ -562,7 +555,7 @@ static void parse_elf_finish(struct elf_info *info)
static int ignore_undef_symbol(struct elf_info *info, const char *symname)
{
/* ignore __this_module, it will be resolved shortly */
- if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0)
+ if (strcmp(symname, VMLINUX_SYMBOL_STR(__this_module)) == 0)
return 1;
/* ignore global offset table */
if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
@@ -583,8 +576,8 @@ static int ignore_undef_symbol(struct elf_info *info, const char *symname)
return 0;
}
-#define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_"
-#define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
+#define CRC_PFX VMLINUX_SYMBOL_STR(__crc_)
+#define KSYMTAB_PFX VMLINUX_SYMBOL_STR(__ksymtab_)
static void handle_modversions(struct module *mod, struct elf_info *info,
Elf_Sym *sym, const char *symname)
@@ -637,11 +630,11 @@ static void handle_modversions(struct module *mod, struct elf_info *info,
}
#endif
- if (memcmp(symname, MODULE_SYMBOL_PREFIX,
- strlen(MODULE_SYMBOL_PREFIX)) == 0) {
+ if (memcmp(symname, VMLINUX_SYMBOL_PREFIX_STR,
+ strlen(VMLINUX_SYMBOL_PREFIX_STR)) == 0) {
mod->unres =
alloc_symbol(symname +
- strlen(MODULE_SYMBOL_PREFIX),
+ strlen(VMLINUX_SYMBOL_PREFIX_STR),
ELF_ST_BIND(sym->st_info) == STB_WEAK,
mod->unres);
}
@@ -652,9 +645,9 @@ static void handle_modversions(struct module *mod, struct elf_info *info,
sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
export);
}
- if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0)
+ if (strcmp(symname, VMLINUX_SYMBOL_STR(init_module)) == 0)
mod->has_init = 1;
- if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0)
+ if (strcmp(symname, VMLINUX_SYMBOL_STR(cleanup_module)) == 0)
mod->has_cleanup = 1;
break;
}
Hi Rusty,
Looks partly better. You seem to be using
CONFIG_SYMBOL_PREFIX_UNDERSCORE but selecting
CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX. One trivial comment below.
Maybe this was an unfinished version of the patch?
On Tue, 12 Mar 2013 15:18:15 +1030 Rusty Russell <[email protected]> wrote:
>
> diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig
> index 600494c..314ee6a 100644
> --- a/arch/blackfin/Kconfig
> +++ b/arch/blackfin/Kconfig
> @@ -45,6 +42,7 @@ config BLACKFIN
> select HAVE_MOD_ARCH_SPECIFIC
> select MODULES_USE_ELF_RELA
>
> +
> config GENERIC_CSUM
> def_bool y
Extra blank line added.
--
Cheers,
Stephen Rothwell [email protected]
Hi Rusty,
On 12/03/13 04:48, Rusty Russell wrote:
> v2: Rename CONFIG_SYMBOL_PREFIX_UNDERSCORE to CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX,
> which is defined in arch/Kconfig and selected by the 3 archs which need it.
Sorry I didn't get a chance to try your patch yesterday.
> Subject: CONFIG_SYMBOL_PREFIX: cleanup.
>
> We have CONFIG_SYMBOL_PREFIX, which three archs define to the string
> "_". But Al Viro broke this in "consolidate cond_syscall and
> SYSCALL_ALIAS declarations", and he's not the first to do so.
>
> Using CONFIG_SYMBOL_PREFIX is awkward, since we usually just want to
> prefix it so something. So various places define helpers which are
> defined to nothing if CONFIG_SYMBOL_PREFIX isn't set:
>
> 1) include/asm-generic/unistd.h defines __SYMBOL_PREFIX.
> 2) include/asm-generic/vmlinux.lds.h defines VMLINUX_SYMBOL(sym)
> 3) include/linux/export.h defines MODULE_SYMBOL_PREFIX.
> 4) include/linux/kernel.h defines SYMBOL_PREFIX (which differs from #7)
> 5) kernel/modsign_certificate.S defines ASM_SYMBOL(sym)
> 6) scripts/modpost.c defines MODULE_SYMBOL_PREFIX
> 7) scripts/Makefile.lib defines SYMBOL_PREFIX on the commandline if
> CONFIG_SYMBOL_PREFIX is set, so that we have a non-string version
> for pasting.
>
> (arch/h8300/include/asm/linkage.h defines SYMBOL_NAME(), too).
>
> Let's solve this properly:
> 1) No more generic prefix, just CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX.
> 2) Make linux/export.h usable from asm.
> 3) Define VMLINUX_SYMBOL, VMLINUX_SYMBOL_NAME and VMLINUX_SYMBOL_PREFIX_STR.
You don't seem to define VMLINUX_SYMBOL_NAME
> 4) Make everyone use them.
>
> Signed-off-by: Rusty Russell <[email protected]>
After a few modifications detailed below (with a fixup patch at the
end for convenience) it seems to work no worse than before for metag
(module symbol versioning was apparently already broken, I need to
look into that).
Reviewed-by: James Hogan <[email protected]>
Tested-by: James Hogan <[email protected]> (on metag)
Cheers
James
>
> diff --git a/Makefile b/Makefile
> index a05ea42..9dc948d 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -1398,7 +1398,7 @@ quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN $(wildcard $(rm-files))
> # Run depmod only if we have System.map and depmod is executable
> quiet_cmd_depmod = DEPMOD $(KERNELRELEASE)
> cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
> - $(KERNELRELEASE) "$(patsubst "%",%,$(CONFIG_SYMBOL_PREFIX))"
> + $(KERNELRELEASE) "$(patsubst y,_,$(CONFIG_SYMBOL_PREFIX_UNDERSCORE))"
should this be CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX now?
> diff --git a/arch/h8300/Kconfig b/arch/h8300/Kconfig
> index ae8551e..ba043e3 100644
> --- a/arch/h8300/Kconfig
> +++ b/arch/h8300/Kconfig
> @@ -12,10 +12,10 @@ config H8300
> select MODULES_USE_ELF_RELA
> select OLD_SIGSUSPEND3
> select OLD_SIGACTION
> + select HAVE_UNDERSCORE_SYMBOL_PREFIX
>
> -config SYMBOL_PREFIX
> - string
> - default "_"
> +config SYMBOL_PREFIX_UNDERSCORE
> + def_bool y
Not needed anymore I think
> diff --git a/arch/metag/Kconfig b/arch/metag/Kconfig
> index afc8973..88272ce 100644
> --- a/arch/metag/Kconfig
> +++ b/arch/metag/Kconfig
> @@ -1,6 +1,5 @@
> -config SYMBOL_PREFIX
> - string
> - default "_"
> +config SYMBOL_PREFIX_UNDERSCORE
> + def_bool y
Same again.
> diff --git a/include/asm-generic/unistd.h b/include/asm-generic/unistd.h
> index 4077b5d..80122d4 100644
> --- a/include/asm-generic/unistd.h
> +++ b/include/asm-generic/unistd.h
> @@ -1,4 +1,5 @@
> #include <uapi/asm-generic/unistd.h>
> +#include <linux/export.h>
>
> /*
> * These are required system calls, we should
> @@ -17,12 +18,7 @@
> * but it doesn't work on all toolchains, so we just do it by hand
> */
> #ifndef cond_syscall
> -#ifdef CONFIG_SYMBOL_PREFIX
> -#define __SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
> -#else
> -#define __SYMBOL_PREFIX
> -#endif
> -#define cond_syscall(x) asm(".weak\t" __SYMBOL_PREFIX #x "\n\t" \
> - ".set\t" __SYMBOL_PREFIX #x "," \
> - __SYMBOL_PREFIX "sys_ni_syscall")
> +#define cond_syscall(x) asm(".weak\t" SYMBOL_NAME_STR(x) "\n\t" \
> + ".set\t" SYMBOL_NAME_STR(x) "," \
> + SYMBOL_NAME_STR(sys_ni_syscall))
s/SYMBOL_NAME_STR/VMLINUX_SYMBOL_STR/
> diff --git a/include/linux/export.h b/include/linux/export.h
> index 696c0f4..0080e93 100644
> --- a/include/linux/export.h
> +++ b/include/linux/export.h
> @@ -7,15 +7,27 @@
> *
> * If you feel the need to add #include <linux/foo.h> to this file
> * then you are doing something wrong and should go away silently.
> + *
> + * If you think the above arrogance just encourages more people to add
> + * random crap to this file, you're not alone.
:-)
> */
>
> /* Some toolchains use a `_' prefix for all user symbols. */
> -#ifdef CONFIG_SYMBOL_PREFIX
> -#define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
> +#ifdef CONFIG_SYMBOL_PREFIX_UNDERSCORE
CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
> diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
> index 3d569d6..d767681 100644
> --- a/scripts/link-vmlinux.sh
> +++ b/scripts/link-vmlinux.sh
> @@ -74,9 +74,8 @@ kallsyms()
> info KSYM ${2}
> local kallsymopt;
>
> - if [ -n "${CONFIG_SYMBOL_PREFIX}" ]; then
> - kallsymopt="${kallsymopt} \
> - --symbol-prefix=${CONFIG_SYMBOL_PREFIX}"
> + if [ -n "${CONFIG_SYMBOL_PREFIX_UNDERSCORE}" ]; then
CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
diff --git a/Makefile b/Makefile
index 9dc948d..0b09ba5 100644
--- a/Makefile
+++ b/Makefile
@@ -1398,7 +1398,7 @@ quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN $(wildcard $(rm-files))
# Run depmod only if we have System.map and depmod is executable
quiet_cmd_depmod = DEPMOD $(KERNELRELEASE)
cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
- $(KERNELRELEASE) "$(patsubst y,_,$(CONFIG_SYMBOL_PREFIX_UNDERSCORE))"
+ $(KERNELRELEASE) "$(patsubst y,_,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX))"
# Create temporary dir for module support files
# clean it up only when building all modules
diff --git a/arch/h8300/Kconfig b/arch/h8300/Kconfig
index ba043e3..2333cf6 100644
--- a/arch/h8300/Kconfig
+++ b/arch/h8300/Kconfig
@@ -14,9 +14,6 @@ config H8300
select OLD_SIGACTION
select HAVE_UNDERSCORE_SYMBOL_PREFIX
-config SYMBOL_PREFIX_UNDERSCORE
- def_bool y
-
config MMU
bool
default n
diff --git a/arch/metag/Kconfig b/arch/metag/Kconfig
index 88272ce..2099617 100644
--- a/arch/metag/Kconfig
+++ b/arch/metag/Kconfig
@@ -1,6 +1,3 @@
-config SYMBOL_PREFIX_UNDERSCORE
- def_bool y
-
config METAG
def_bool y
select EMBEDDED
diff --git a/include/asm-generic/unistd.h b/include/asm-generic/unistd.h
index 80122d4..15c0598 100644
--- a/include/asm-generic/unistd.h
+++ b/include/asm-generic/unistd.h
@@ -18,7 +18,7 @@
* but it doesn't work on all toolchains, so we just do it by hand
*/
#ifndef cond_syscall
-#define cond_syscall(x) asm(".weak\t" SYMBOL_NAME_STR(x) "\n\t" \
- ".set\t" SYMBOL_NAME_STR(x) "," \
- SYMBOL_NAME_STR(sys_ni_syscall))
+#define cond_syscall(x) asm(".weak\t" VMLINUX_SYMBOL_STR(x) "\n\t" \
+ ".set\t" VMLINUX_SYMBOL_STR(x) "," \
+ VMLINUX_SYMBOL_STR(sys_ni_syscall))
#endif
diff --git a/include/linux/export.h b/include/linux/export.h
index 0080e93..fc83b2a 100644
--- a/include/linux/export.h
+++ b/include/linux/export.h
@@ -13,7 +13,7 @@
*/
/* Some toolchains use a `_' prefix for all user symbols. */
-#ifdef CONFIG_SYMBOL_PREFIX_UNDERSCORE
+#ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
#define __VMLINUX_SYMBOL(x) _##x
#define __VMLINUX_SYMBOL_STR(x) "_" #x
#define VMLINUX_SYMBOL_PREFIX_STR "_"
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index d767681..0149949 100644
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -74,7 +74,7 @@ kallsyms()
info KSYM ${2}
local kallsymopt;
- if [ -n "${CONFIG_SYMBOL_PREFIX_UNDERSCORE}" ]; then
+ if [ -n "${CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX}" ]; then
kallsymopt="${kallsymopt} --symbol-prefix=_"
fi
Stephen Rothwell <[email protected]> writes:
> Hi Rusty,
>
> Looks partly better. You seem to be using
> CONFIG_SYMBOL_PREFIX_UNDERSCORE but selecting
> CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX. One trivial comment below.
>
> Maybe this was an unfinished version of the patch?
Indeed. It was crap.... now I've applied James' copious fixes, and
actually, y'know, proof-read it.
This is what I'll push into my fixes/ branch now, and if it survives a
day in linux-next, will push to Linus.
Thanks,
Rusty.
v2: Rename CONFIG_SYMBOL_PREFIX_UNDERSCORE to
CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX, which is defined in
arch/Kconfig and selected by the 3 archs which need it.
v3: Clean up remnants of v1, s/VMLINUX_SYMBOL_NAME/VMLINUX_SYMBOL_STR/
in description, note that Al's commit is in linux-next only,
remove whitespace-only hunk.
CONFIG_SYMBOL_PREFIX: cleanup.
We have CONFIG_SYMBOL_PREFIX, which three archs define to the string
"_". But Al Viro broke this in "consolidate cond_syscall and
SYSCALL_ALIAS declarations" (in linux-next), and he's not the first to
do so.
Using CONFIG_SYMBOL_PREFIX is awkward, since we usually just want to
prefix it so something. So various places define helpers which are
defined to nothing if CONFIG_SYMBOL_PREFIX isn't set:
1) include/asm-generic/unistd.h defines __SYMBOL_PREFIX.
2) include/asm-generic/vmlinux.lds.h defines VMLINUX_SYMBOL(sym)
3) include/linux/export.h defines MODULE_SYMBOL_PREFIX.
4) include/linux/kernel.h defines SYMBOL_PREFIX (which differs from #7)
5) kernel/modsign_certificate.S defines ASM_SYMBOL(sym)
6) scripts/modpost.c defines MODULE_SYMBOL_PREFIX
7) scripts/Makefile.lib defines SYMBOL_PREFIX on the commandline if
CONFIG_SYMBOL_PREFIX is set, so that we have a non-string version
for pasting.
(arch/h8300/include/asm/linkage.h defines SYMBOL_NAME(), too).
Let's solve this properly:
1) No more generic prefix, just CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX.
2) Make linux/export.h usable from asm.
3) Define VMLINUX_SYMBOL, VMLINUX_SYMBOL_STR and VMLINUX_SYMBOL_PREFIX_STR.
4) Make everyone use them.
Signed-off-by: Rusty Russell <[email protected]>
Reviewed-by: James Hogan <[email protected]>
Tested-by: James Hogan <[email protected]> (on metag)
diff --git a/Makefile b/Makefile
index a05ea42..10fb6c7 100644
--- a/Makefile
+++ b/Makefile
@@ -1398,7 +1398,7 @@ quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN $(wildcard $(rm-files))
# Run depmod only if we have System.map and depmod is executable
quiet_cmd_depmod = DEPMOD $(KERNELRELEASE)
cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
- $(KERNELRELEASE) "$(patsubst "%",%,$(CONFIG_SYMBOL_PREFIX))"
+ $(KERNELRELEASE) "$(patsubst y,_,$(CONFIG_HAVE_SYMBOL_PREFIX_UNDERSCORE))"
# Create temporary dir for module support files
# clean it up only when building all modules
diff --git a/arch/Kconfig b/arch/Kconfig
index 5a1779c..12ba8f9 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -391,6 +391,12 @@ config MODULES_USE_ELF_REL
Modules only use ELF REL relocations. Modules with ELF RELA
relocations will give an error.
+config HAVE_UNDERSCORE_SYMBOL_PREFIX
+ bool
+ help
+ Some architectures generate an _ in front of C symbols; things like
+ module loading and assembly files need to know about this.
+
#
# ABI hall of shame
#
diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig
index 600494c..314ee6a 100644
--- a/arch/blackfin/Kconfig
+++ b/arch/blackfin/Kconfig
@@ -1,7 +1,3 @@
-config SYMBOL_PREFIX
- string
- default "_"
-
config MMU
def_bool n
@@ -33,6 +29,7 @@ config BLACKFIN
select ARCH_HAVE_CUSTOM_GPIO_H
select ARCH_WANT_OPTIONAL_GPIOLIB
select HAVE_UID16
+ select HAVE_UNDERSCORE_SYMBOL_PREFIX
select HAVE_VIRT_TO_BUS
select ARCH_WANT_IPC_PARSE_VERSION
select HAVE_GENERIC_HARDIRQS
diff --git a/arch/h8300/Kconfig b/arch/h8300/Kconfig
index ae8551e..2333cf6 100644
--- a/arch/h8300/Kconfig
+++ b/arch/h8300/Kconfig
@@ -12,10 +12,7 @@ config H8300
select MODULES_USE_ELF_RELA
select OLD_SIGSUSPEND3
select OLD_SIGACTION
-
-config SYMBOL_PREFIX
- string
- default "_"
+ select HAVE_UNDERSCORE_SYMBOL_PREFIX
config MMU
bool
diff --git a/arch/metag/Kconfig b/arch/metag/Kconfig
index afc8973..2099617 100644
--- a/arch/metag/Kconfig
+++ b/arch/metag/Kconfig
@@ -1,7 +1,3 @@
-config SYMBOL_PREFIX
- string
- default "_"
-
config METAG
def_bool y
select EMBEDDED
@@ -27,6 +23,7 @@ config METAG
select HAVE_MOD_ARCH_SPECIFIC
select HAVE_PERF_EVENTS
select HAVE_SYSCALL_TRACEPOINTS
+ select HAVE_UNDERSCORE_SYMBOL_PREFIX
select IRQ_DOMAIN
select MODULES_USE_ELF_RELA
select OF
diff --git a/drivers/mtd/chips/gen_probe.c b/drivers/mtd/chips/gen_probe.c
index 3b9a284..00d20ad 100644
--- a/drivers/mtd/chips/gen_probe.c
+++ b/drivers/mtd/chips/gen_probe.c
@@ -204,14 +204,14 @@ static inline struct mtd_info *cfi_cmdset_unknown(struct map_info *map,
struct cfi_private *cfi = map->fldrv_priv;
__u16 type = primary?cfi->cfiq->P_ID:cfi->cfiq->A_ID;
#ifdef CONFIG_MODULES
- char probename[16+sizeof(MODULE_SYMBOL_PREFIX)];
+ char probename[16+sizeof(VMLINUX_SYMBOL_PREFIX_STR)];
cfi_cmdset_fn_t *probe_function;
- sprintf(probename, MODULE_SYMBOL_PREFIX "cfi_cmdset_%4.4X", type);
+ sprintf(probename, VMLINUX_SYMBOL_PREFIX_STR "cfi_cmdset_%4.4X", type);
probe_function = __symbol_get(probename);
if (!probe_function) {
- request_module(probename + sizeof(MODULE_SYMBOL_PREFIX) - 1);
+ request_module(probename + sizeof(VMLINUX_SYMBOL_PREFIX_STR)-1);
probe_function = __symbol_get(probename);
}
diff --git a/include/asm-generic/unistd.h b/include/asm-generic/unistd.h
index 4077b5d..15c0598 100644
--- a/include/asm-generic/unistd.h
+++ b/include/asm-generic/unistd.h
@@ -1,4 +1,5 @@
#include <uapi/asm-generic/unistd.h>
+#include <linux/export.h>
/*
* These are required system calls, we should
@@ -17,12 +18,7 @@
* but it doesn't work on all toolchains, so we just do it by hand
*/
#ifndef cond_syscall
-#ifdef CONFIG_SYMBOL_PREFIX
-#define __SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
-#else
-#define __SYMBOL_PREFIX
-#endif
-#define cond_syscall(x) asm(".weak\t" __SYMBOL_PREFIX #x "\n\t" \
- ".set\t" __SYMBOL_PREFIX #x "," \
- __SYMBOL_PREFIX "sys_ni_syscall")
+#define cond_syscall(x) asm(".weak\t" VMLINUX_SYMBOL_STR(x) "\n\t" \
+ ".set\t" VMLINUX_SYMBOL_STR(x) "," \
+ VMLINUX_SYMBOL_STR(sys_ni_syscall))
#endif
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index afa12c7..eb58d2d 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -52,13 +52,7 @@
#define LOAD_OFFSET 0
#endif
-#ifndef SYMBOL_PREFIX
-#define VMLINUX_SYMBOL(sym) sym
-#else
-#define PASTE2(x,y) x##y
-#define PASTE(x,y) PASTE2(x,y)
-#define VMLINUX_SYMBOL(sym) PASTE(SYMBOL_PREFIX, sym)
-#endif
+#include <linux/export.h>
/* Align . to a 8 byte boundary equals to maximum function alignment. */
#define ALIGN_FUNCTION() . = ALIGN(8)
diff --git a/include/linux/export.h b/include/linux/export.h
index 696c0f4..fc83b2a 100644
--- a/include/linux/export.h
+++ b/include/linux/export.h
@@ -7,15 +7,27 @@
*
* If you feel the need to add #include <linux/foo.h> to this file
* then you are doing something wrong and should go away silently.
+ *
+ * If you think the above arrogance just encourages more people to add
+ * random crap to this file, you're not alone.
*/
/* Some toolchains use a `_' prefix for all user symbols. */
-#ifdef CONFIG_SYMBOL_PREFIX
-#define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
+#ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
+#define __VMLINUX_SYMBOL(x) _##x
+#define __VMLINUX_SYMBOL_STR(x) "_" #x
+#define VMLINUX_SYMBOL_PREFIX_STR "_"
#else
-#define MODULE_SYMBOL_PREFIX ""
+#define __VMLINUX_SYMBOL(x) x
+#define __VMLINUX_SYMBOL_STR(x) #x
+#define VMLINUX_SYMBOL_PREFIX_STR ""
#endif
+/* Indirect, so macros are expanded before pasting. */
+#define VMLINUX_SYMBOL(x) __VMLINUX_SYMBOL(x)
+#define VMLINUX_SYMBOL_STR(x) __VMLINUX_SYMBOL_STR(x)
+
+#ifndef __ASSEMBLY__
struct kernel_symbol
{
unsigned long value;
@@ -51,7 +63,7 @@ extern struct module __this_module;
__CRC_SYMBOL(sym, sec) \
static const char __kstrtab_##sym[] \
__attribute__((section("__ksymtab_strings"), aligned(1))) \
- = MODULE_SYMBOL_PREFIX #sym; \
+ = VMLINUX_SYMBOL_STR(sym); \
static const struct kernel_symbol __ksymtab_##sym \
__used \
__attribute__((section("___ksymtab" sec "+" #sym), unused)) \
@@ -85,5 +97,6 @@ extern struct module __this_module;
#define EXPORT_UNUSED_SYMBOL_GPL(sym)
#endif /* CONFIG_MODULES */
+#endif /* !__ASSEMBLY__ */
#endif /* _LINUX_EXPORT_H */
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 80d3687..e13e992 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -723,13 +723,6 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
/* Trap pasters of __FUNCTION__ at compile-time */
#define __FUNCTION__ (__func__)
-/* This helps us to avoid #ifdef CONFIG_SYMBOL_PREFIX */
-#ifdef CONFIG_SYMBOL_PREFIX
-#define SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
-#else
-#define SYMBOL_PREFIX ""
-#endif
-
/* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
# define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
diff --git a/include/linux/module.h b/include/linux/module.h
index ead1b57..46f1ea0 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -190,7 +190,7 @@ extern int modules_disabled; /* for sysctl */
/* Get/put a kernel symbol (calls must be symmetric) */
void *__symbol_get(const char *symbol);
void *__symbol_get_gpl(const char *symbol);
-#define symbol_get(x) ((typeof(&x))(__symbol_get(MODULE_SYMBOL_PREFIX #x)))
+#define symbol_get(x) ((typeof(&x))(__symbol_get(VMLINUX_SYMBOL_STR(x))))
/* modules using other modules: kdb wants to see this. */
struct module_use {
@@ -453,7 +453,7 @@ extern void __module_put_and_exit(struct module *mod, long code)
#ifdef CONFIG_MODULE_UNLOAD
unsigned long module_refcount(struct module *mod);
void __symbol_put(const char *symbol);
-#define symbol_put(x) __symbol_put(MODULE_SYMBOL_PREFIX #x)
+#define symbol_put(x) __symbol_put(VMLINUX_SYMBOL_STR(x))
void symbol_put_addr(void *addr);
/* Sometimes we know we already have a refcount, and it's easier not
diff --git a/kernel/modsign_certificate.S b/kernel/modsign_certificate.S
index 246b4c6..4a9a86d 100644
--- a/kernel/modsign_certificate.S
+++ b/kernel/modsign_certificate.S
@@ -1,15 +1,8 @@
-/* SYMBOL_PREFIX defined on commandline from CONFIG_SYMBOL_PREFIX */
-#ifndef SYMBOL_PREFIX
-#define ASM_SYMBOL(sym) sym
-#else
-#define PASTE2(x,y) x##y
-#define PASTE(x,y) PASTE2(x,y)
-#define ASM_SYMBOL(sym) PASTE(SYMBOL_PREFIX, sym)
-#endif
+#include <linux/export.h>
#define GLOBAL(name) \
- .globl ASM_SYMBOL(name); \
- ASM_SYMBOL(name):
+ .globl VMLINUX_SYMBOL(name); \
+ VMLINUX_SYMBOL(name):
.section ".init.data","aw"
diff --git a/kernel/module.c b/kernel/module.c
index 0925c9a..cfd4a3f 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1209,7 +1209,7 @@ static inline int check_modstruct_version(Elf_Shdr *sechdrs,
/* Since this should be found in kernel (which can't be removed),
* no locking is necessary. */
- if (!find_symbol(MODULE_SYMBOL_PREFIX "module_layout", NULL,
+ if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
&crc, true, false))
BUG();
return check_version(sechdrs, versindex, "module_layout", mod, crc,
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 07125e6..a373a1f 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -119,13 +119,6 @@ _c_flags += $(if $(patsubst n%,, \
$(CFLAGS_GCOV))
endif
-ifdef CONFIG_SYMBOL_PREFIX
-_sym_flags = -DSYMBOL_PREFIX=$(patsubst "%",%,$(CONFIG_SYMBOL_PREFIX))
-_cpp_flags += $(_sym_flags)
-_a_flags += $(_sym_flags)
-endif
-
-
# If building the kernel in a separate objtree expand all occurrences
# of -Idir to -I$(srctree)/dir except for absolute paths (starting with '/').
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index 3d569d6..0149949 100644
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -74,9 +74,8 @@ kallsyms()
info KSYM ${2}
local kallsymopt;
- if [ -n "${CONFIG_SYMBOL_PREFIX}" ]; then
- kallsymopt="${kallsymopt} \
- --symbol-prefix=${CONFIG_SYMBOL_PREFIX}"
+ if [ -n "${CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX}" ]; then
+ kallsymopt="${kallsymopt} --symbol-prefix=_"
fi
if [ -n "${CONFIG_KALLSYMS_ALL}" ]; then
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 78b30c1..6985021 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -18,14 +18,7 @@
#include "modpost.h"
#include "../../include/generated/autoconf.h"
#include "../../include/linux/license.h"
-
-/* Some toolchains use a `_' prefix for all user symbols. */
-#ifdef CONFIG_SYMBOL_PREFIX
-#define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
-#else
-#define MODULE_SYMBOL_PREFIX ""
-#endif
-
+#include "../../include/linux/export.h"
/* Are we using CONFIG_MODVERSIONS? */
int modversions = 0;
@@ -562,7 +555,7 @@ static void parse_elf_finish(struct elf_info *info)
static int ignore_undef_symbol(struct elf_info *info, const char *symname)
{
/* ignore __this_module, it will be resolved shortly */
- if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0)
+ if (strcmp(symname, VMLINUX_SYMBOL_STR(__this_module)) == 0)
return 1;
/* ignore global offset table */
if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
@@ -583,8 +576,8 @@ static int ignore_undef_symbol(struct elf_info *info, const char *symname)
return 0;
}
-#define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_"
-#define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
+#define CRC_PFX VMLINUX_SYMBOL_STR(__crc_)
+#define KSYMTAB_PFX VMLINUX_SYMBOL_STR(__ksymtab_)
static void handle_modversions(struct module *mod, struct elf_info *info,
Elf_Sym *sym, const char *symname)
@@ -637,11 +630,11 @@ static void handle_modversions(struct module *mod, struct elf_info *info,
}
#endif
- if (memcmp(symname, MODULE_SYMBOL_PREFIX,
- strlen(MODULE_SYMBOL_PREFIX)) == 0) {
+ if (memcmp(symname, VMLINUX_SYMBOL_PREFIX_STR,
+ strlen(VMLINUX_SYMBOL_PREFIX_STR)) == 0) {
mod->unres =
alloc_symbol(symname +
- strlen(MODULE_SYMBOL_PREFIX),
+ strlen(VMLINUX_SYMBOL_PREFIX_STR),
ELF_ST_BIND(sym->st_info) == STB_WEAK,
mod->unres);
}
@@ -652,9 +645,9 @@ static void handle_modversions(struct module *mod, struct elf_info *info,
sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
export);
}
- if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0)
+ if (strcmp(symname, VMLINUX_SYMBOL_STR(init_module)) == 0)
mod->has_init = 1;
- if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0)
+ if (strcmp(symname, VMLINUX_SYMBOL_STR(cleanup_module)) == 0)
mod->has_cleanup = 1;
break;
}
> actually, y'know, proof-read it.
Hmm..
> + $(KERNELRELEASE) "$(patsubst y,_,$(CONFIG_HAVE_SYMBOL_PREFIX_UNDERSCORE))"
>
> +config HAVE_UNDERSCORE_SYMBOL_PREFIX
HAVE_UNDERSCORE_... or HAVE_SYMBOL_... confusion.
I prefer the HAVE_SYMBOL_... variant but no strong feelings..
> + *
> + * If you think the above arrogance just encourages more people to add
> + * random crap to this file, you're not alone.
Kill this.
> /* Some toolchains use a `_' prefix for all user symbols. */
> -#ifdef CONFIG_SYMBOL_PREFIX
> -#define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
> +#ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
> +#define __VMLINUX_SYMBOL(x) _##x
> +#define __VMLINUX_SYMBOL_STR(x) "_" #x
> +#define VMLINUX_SYMBOL_PREFIX_STR "_"
> #else
> -#define MODULE_SYMBOL_PREFIX ""
> +#define __VMLINUX_SYMBOL(x) x
> +#define __VMLINUX_SYMBOL_STR(x) #x
> +#define VMLINUX_SYMBOL_PREFIX_STR ""
> #endif
We know the prefix is an underscore. No benefits from defining
VMLINUX_SYMBOL_PREFIX_STR. The config name even syas so.
Skipping the above give us only one way to check
for the prefix - today we mix the two.
Sam
Hi Sam,
On 13/03/13 06:31, Sam Ravnborg wrote:
>> /* Some toolchains use a `_' prefix for all user symbols. */
>> -#ifdef CONFIG_SYMBOL_PREFIX
>> -#define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
>> +#ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
>> +#define __VMLINUX_SYMBOL(x) _##x
>> +#define __VMLINUX_SYMBOL_STR(x) "_" #x
>> +#define VMLINUX_SYMBOL_PREFIX_STR "_"
>> #else
>> -#define MODULE_SYMBOL_PREFIX ""
>> +#define __VMLINUX_SYMBOL(x) x
>> +#define __VMLINUX_SYMBOL_STR(x) #x
>> +#define VMLINUX_SYMBOL_PREFIX_STR ""
>> #endif
>
> We know the prefix is an underscore. No benefits from defining
> VMLINUX_SYMBOL_PREFIX_STR.
scripts/modpost.c uses the actual prefix string though:
> if (memcmp(symname, MODULE_SYMBOL_PREFIX,
> strlen(MODULE_SYMBOL_PREFIX)) == 0) {
> mod->unres =
> alloc_symbol(symname +
> strlen(MODULE_SYMBOL_PREFIX),
> ELF_ST_BIND(sym->st_info) == STB_WEAK,
> mod->unres);
See also my "module: fix symbol versioning with symbol prefixes" patch
for an additional use in modpost.
Having a MODULE_SYMBOL_PREFIX/VMLINUX_SYMBOL_PREFIX_STR seems like the
simplest way to keep this code clean and readable without special cases.
Cheers
James
On Wed, Mar 13, 2013 at 09:21:01AM +0000, James Hogan wrote:
> Hi Sam,
>
> On 13/03/13 06:31, Sam Ravnborg wrote:
> >> /* Some toolchains use a `_' prefix for all user symbols. */
> >> -#ifdef CONFIG_SYMBOL_PREFIX
> >> -#define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
> >> +#ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
> >> +#define __VMLINUX_SYMBOL(x) _##x
> >> +#define __VMLINUX_SYMBOL_STR(x) "_" #x
> >> +#define VMLINUX_SYMBOL_PREFIX_STR "_"
> >> #else
> >> -#define MODULE_SYMBOL_PREFIX ""
> >> +#define __VMLINUX_SYMBOL(x) x
> >> +#define __VMLINUX_SYMBOL_STR(x) #x
> >> +#define VMLINUX_SYMBOL_PREFIX_STR ""
> >> #endif
> >
> > We know the prefix is an underscore. No benefits from defining
> > VMLINUX_SYMBOL_PREFIX_STR.
>
> scripts/modpost.c uses the actual prefix string though:
>
> > if (memcmp(symname, MODULE_SYMBOL_PREFIX,
> > strlen(MODULE_SYMBOL_PREFIX)) == 0) {
> > mod->unres =
> > alloc_symbol(symname +
> > strlen(MODULE_SYMBOL_PREFIX),
> > ELF_ST_BIND(sym->st_info) == STB_WEAK,
> > mod->unres);
>
Allowing ourself to know this is "_" then we could make the above code look
something like:
if (have_symbol_prefix_underscore) {
if (symname[0] == '_') {
mod->unres =
...
But I do not feel strong about this part.
It is much more important to clean up so we use the
same definition all over the kernel.
Sam
Sam Ravnborg <[email protected]> writes:
>> actually, y'know, proof-read it.
> Hmm..
>> + $(KERNELRELEASE) "$(patsubst y,_,$(CONFIG_HAVE_SYMBOL_PREFIX_UNDERSCORE))"
>>
>> +config HAVE_UNDERSCORE_SYMBOL_PREFIX
>
> HAVE_UNDERSCORE_... or HAVE_SYMBOL_... confusion.
> I prefer the HAVE_SYMBOL_... variant but no strong feelings..
Thanks, fixed. (HAVE_UNDERSCORE_ won by grep majority vote, but I don't
really care either).
>> + *
>> + * If you think the above arrogance just encourages more people to add
>> + * random crap to this file, you're not alone.
> Kill this.
?? It went in without my Ack, and it's a particularly offensive turd.
I can replace it with a civilized comment, instead of being snarky
though...
>> /* Some toolchains use a `_' prefix for all user symbols. */
>> -#ifdef CONFIG_SYMBOL_PREFIX
>> -#define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
>> +#ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
>> +#define __VMLINUX_SYMBOL(x) _##x
>> +#define __VMLINUX_SYMBOL_STR(x) "_" #x
>> +#define VMLINUX_SYMBOL_PREFIX_STR "_"
>> #else
>> -#define MODULE_SYMBOL_PREFIX ""
>> +#define __VMLINUX_SYMBOL(x) x
>> +#define __VMLINUX_SYMBOL_STR(x) #x
>> +#define VMLINUX_SYMBOL_PREFIX_STR ""
>> #endif
>
> We know the prefix is an underscore. No benefits from defining
> VMLINUX_SYMBOL_PREFIX_STR. The config name even syas so.
> Skipping the above give us only one way to check
> for the prefix - today we mix the two.
After testing, I think you're right. The two users are both slightly
clearer after this (though mtd is a tiny bit less optimal).
Note: James, your patch hunk now looks like this:
- buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name);
+ buf_printf(b, "\t{ %#8x, VMLINUX_SYMBOL_STR(%s) },\n",
+ s->crc, s->name);
Here's version 3:
From: Rusty Russell <[email protected]>
Subject: CONFIG_SYMBOL_PREFIX: cleanup.
We have CONFIG_SYMBOL_PREFIX, which three archs define to the string
"_". But Al Viro broke this in "consolidate cond_syscall and
SYSCALL_ALIAS declarations" (in linux-next), and he's not the first to
do so.
Using CONFIG_SYMBOL_PREFIX is awkward, since we usually just want to
prefix it so something. So various places define helpers which are
defined to nothing if CONFIG_SYMBOL_PREFIX isn't set:
1) include/asm-generic/unistd.h defines __SYMBOL_PREFIX.
2) include/asm-generic/vmlinux.lds.h defines VMLINUX_SYMBOL(sym)
3) include/linux/export.h defines MODULE_SYMBOL_PREFIX.
4) include/linux/kernel.h defines SYMBOL_PREFIX (which differs from #7)
5) kernel/modsign_certificate.S defines ASM_SYMBOL(sym)
6) scripts/modpost.c defines MODULE_SYMBOL_PREFIX
7) scripts/Makefile.lib defines SYMBOL_PREFIX on the commandline if
CONFIG_SYMBOL_PREFIX is set, so that we have a non-string version
for pasting.
(arch/h8300/include/asm/linkage.h defines SYMBOL_NAME(), too).
Let's solve this properly:
1) No more generic prefix, just CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX.
2) Make linux/export.h usable from asm.
3) Define VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR().
4) Make everyone use them.
Signed-off-by: Rusty Russell <[email protected]>
diff --git a/Makefile b/Makefile
index a05ea42..0b09ba5 100644
--- a/Makefile
+++ b/Makefile
@@ -1398,7 +1398,7 @@ quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN $(wildcard $(rm-files))
# Run depmod only if we have System.map and depmod is executable
quiet_cmd_depmod = DEPMOD $(KERNELRELEASE)
cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
- $(KERNELRELEASE) "$(patsubst "%",%,$(CONFIG_SYMBOL_PREFIX))"
+ $(KERNELRELEASE) "$(patsubst y,_,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX))"
# Create temporary dir for module support files
# clean it up only when building all modules
diff --git a/arch/Kconfig b/arch/Kconfig
index 1455579..7b433a4 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -384,6 +384,12 @@ config MODULES_USE_ELF_REL
Modules only use ELF REL relocations. Modules with ELF RELA
relocations will give an error.
+config HAVE_UNDERSCORE_SYMBOL_PREFIX
+ bool
+ help
+ Some architectures generate an _ in front of C symbols; things like
+ module loading and assembly files need to know about this.
+
#
# ABI hall of shame
#
diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig
index c3f2e0b..453ebe4 100644
--- a/arch/blackfin/Kconfig
+++ b/arch/blackfin/Kconfig
@@ -1,7 +1,3 @@
-config SYMBOL_PREFIX
- string
- default "_"
-
config MMU
def_bool n
@@ -33,6 +29,7 @@ config BLACKFIN
select ARCH_HAVE_CUSTOM_GPIO_H
select ARCH_WANT_OPTIONAL_GPIOLIB
select HAVE_UID16
+ select HAVE_UNDERSCORE_SYMBOL_PREFIX
select VIRT_TO_BUS
select ARCH_WANT_IPC_PARSE_VERSION
select HAVE_GENERIC_HARDIRQS
diff --git a/arch/h8300/Kconfig b/arch/h8300/Kconfig
index 79250de..303e4f9 100644
--- a/arch/h8300/Kconfig
+++ b/arch/h8300/Kconfig
@@ -12,10 +12,7 @@ config H8300
select MODULES_USE_ELF_RELA
select OLD_SIGSUSPEND3
select OLD_SIGACTION
-
-config SYMBOL_PREFIX
- string
- default "_"
+ select HAVE_UNDERSCORE_SYMBOL_PREFIX
config MMU
bool
diff --git a/arch/metag/Kconfig b/arch/metag/Kconfig
index afc8973..2099617 100644
--- a/arch/metag/Kconfig
+++ b/arch/metag/Kconfig
@@ -1,7 +1,3 @@
-config SYMBOL_PREFIX
- string
- default "_"
-
config METAG
def_bool y
select EMBEDDED
@@ -27,6 +23,7 @@ config METAG
select HAVE_MOD_ARCH_SPECIFIC
select HAVE_PERF_EVENTS
select HAVE_SYSCALL_TRACEPOINTS
+ select HAVE_UNDERSCORE_SYMBOL_PREFIX
select IRQ_DOMAIN
select MODULES_USE_ELF_RELA
select OF
diff --git a/drivers/mtd/chips/gen_probe.c b/drivers/mtd/chips/gen_probe.c
index 3b9a284..74dbb6b 100644
--- a/drivers/mtd/chips/gen_probe.c
+++ b/drivers/mtd/chips/gen_probe.c
@@ -204,14 +204,16 @@ static inline struct mtd_info *cfi_cmdset_unknown(struct map_info *map,
struct cfi_private *cfi = map->fldrv_priv;
__u16 type = primary?cfi->cfiq->P_ID:cfi->cfiq->A_ID;
#ifdef CONFIG_MODULES
- char probename[16+sizeof(MODULE_SYMBOL_PREFIX)];
+ char probename[sizeof(VMLINUX_SYMBOL_STR(cfi_cmdset_%4.4X))];
cfi_cmdset_fn_t *probe_function;
- sprintf(probename, MODULE_SYMBOL_PREFIX "cfi_cmdset_%4.4X", type);
+ sprintf(probename, VMLINUX_SYMBOL_STR(cfi_cmdset_%4.4X), type);
probe_function = __symbol_get(probename);
if (!probe_function) {
- request_module(probename + sizeof(MODULE_SYMBOL_PREFIX) - 1);
+ char modname[sizeof("cfi_cmdset_%4.4X")];
+ sprintf(modname, "cfi_cmdset_%4.4X", type);
+ request_module(modname);
probe_function = __symbol_get(probename);
}
diff --git a/include/asm-generic/unistd.h b/include/asm-generic/unistd.h
index 4077b5d..15c0598 100644
--- a/include/asm-generic/unistd.h
+++ b/include/asm-generic/unistd.h
@@ -1,4 +1,5 @@
#include <uapi/asm-generic/unistd.h>
+#include <linux/export.h>
/*
* These are required system calls, we should
@@ -17,12 +18,7 @@
* but it doesn't work on all toolchains, so we just do it by hand
*/
#ifndef cond_syscall
-#ifdef CONFIG_SYMBOL_PREFIX
-#define __SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
-#else
-#define __SYMBOL_PREFIX
-#endif
-#define cond_syscall(x) asm(".weak\t" __SYMBOL_PREFIX #x "\n\t" \
- ".set\t" __SYMBOL_PREFIX #x "," \
- __SYMBOL_PREFIX "sys_ni_syscall")
+#define cond_syscall(x) asm(".weak\t" VMLINUX_SYMBOL_STR(x) "\n\t" \
+ ".set\t" VMLINUX_SYMBOL_STR(x) "," \
+ VMLINUX_SYMBOL_STR(sys_ni_syscall))
#endif
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index afa12c7..eb58d2d 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -52,13 +52,7 @@
#define LOAD_OFFSET 0
#endif
-#ifndef SYMBOL_PREFIX
-#define VMLINUX_SYMBOL(sym) sym
-#else
-#define PASTE2(x,y) x##y
-#define PASTE(x,y) PASTE2(x,y)
-#define VMLINUX_SYMBOL(sym) PASTE(SYMBOL_PREFIX, sym)
-#endif
+#include <linux/export.h>
/* Align . to a 8 byte boundary equals to maximum function alignment. */
#define ALIGN_FUNCTION() . = ALIGN(8)
diff --git a/include/linux/export.h b/include/linux/export.h
index 696c0f4..412cd50 100644
--- a/include/linux/export.h
+++ b/include/linux/export.h
@@ -5,17 +5,24 @@
* to reduce the amount of pointless cruft we feed to gcc when only
* exporting a simple symbol or two.
*
- * If you feel the need to add #include <linux/foo.h> to this file
- * then you are doing something wrong and should go away silently.
+ * Try not to add #includes here. It slows compilation and makes kernel
+ * hackers place grumpy comments in header files.
*/
/* Some toolchains use a `_' prefix for all user symbols. */
-#ifdef CONFIG_SYMBOL_PREFIX
-#define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
+#ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
+#define __VMLINUX_SYMBOL(x) _##x
+#define __VMLINUX_SYMBOL_STR(x) "_" #x
#else
-#define MODULE_SYMBOL_PREFIX ""
+#define __VMLINUX_SYMBOL(x) x
+#define __VMLINUX_SYMBOL_STR(x) #x
#endif
+/* Indirect, so macros are expanded before pasting. */
+#define VMLINUX_SYMBOL(x) __VMLINUX_SYMBOL(x)
+#define VMLINUX_SYMBOL_STR(x) __VMLINUX_SYMBOL_STR(x)
+
+#ifndef __ASSEMBLY__
struct kernel_symbol
{
unsigned long value;
@@ -51,7 +58,7 @@ extern struct module __this_module;
__CRC_SYMBOL(sym, sec) \
static const char __kstrtab_##sym[] \
__attribute__((section("__ksymtab_strings"), aligned(1))) \
- = MODULE_SYMBOL_PREFIX #sym; \
+ = VMLINUX_SYMBOL_STR(sym); \
static const struct kernel_symbol __ksymtab_##sym \
__used \
__attribute__((section("___ksymtab" sec "+" #sym), unused)) \
@@ -85,5 +92,6 @@ extern struct module __this_module;
#define EXPORT_UNUSED_SYMBOL_GPL(sym)
#endif /* CONFIG_MODULES */
+#endif /* !__ASSEMBLY__ */
#endif /* _LINUX_EXPORT_H */
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 80d3687..e13e992 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -723,13 +723,6 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
/* Trap pasters of __FUNCTION__ at compile-time */
#define __FUNCTION__ (__func__)
-/* This helps us to avoid #ifdef CONFIG_SYMBOL_PREFIX */
-#ifdef CONFIG_SYMBOL_PREFIX
-#define SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
-#else
-#define SYMBOL_PREFIX ""
-#endif
-
/* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
# define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
diff --git a/include/linux/module.h b/include/linux/module.h
index ead1b57..46f1ea0 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -190,7 +190,7 @@ extern int modules_disabled; /* for sysctl */
/* Get/put a kernel symbol (calls must be symmetric) */
void *__symbol_get(const char *symbol);
void *__symbol_get_gpl(const char *symbol);
-#define symbol_get(x) ((typeof(&x))(__symbol_get(MODULE_SYMBOL_PREFIX #x)))
+#define symbol_get(x) ((typeof(&x))(__symbol_get(VMLINUX_SYMBOL_STR(x))))
/* modules using other modules: kdb wants to see this. */
struct module_use {
@@ -453,7 +453,7 @@ extern void __module_put_and_exit(struct module *mod, long code)
#ifdef CONFIG_MODULE_UNLOAD
unsigned long module_refcount(struct module *mod);
void __symbol_put(const char *symbol);
-#define symbol_put(x) __symbol_put(MODULE_SYMBOL_PREFIX #x)
+#define symbol_put(x) __symbol_put(VMLINUX_SYMBOL_STR(x))
void symbol_put_addr(void *addr);
/* Sometimes we know we already have a refcount, and it's easier not
diff --git a/kernel/modsign_certificate.S b/kernel/modsign_certificate.S
index 246b4c6..4a9a86d 100644
--- a/kernel/modsign_certificate.S
+++ b/kernel/modsign_certificate.S
@@ -1,15 +1,8 @@
-/* SYMBOL_PREFIX defined on commandline from CONFIG_SYMBOL_PREFIX */
-#ifndef SYMBOL_PREFIX
-#define ASM_SYMBOL(sym) sym
-#else
-#define PASTE2(x,y) x##y
-#define PASTE(x,y) PASTE2(x,y)
-#define ASM_SYMBOL(sym) PASTE(SYMBOL_PREFIX, sym)
-#endif
+#include <linux/export.h>
#define GLOBAL(name) \
- .globl ASM_SYMBOL(name); \
- ASM_SYMBOL(name):
+ .globl VMLINUX_SYMBOL(name); \
+ VMLINUX_SYMBOL(name):
.section ".init.data","aw"
diff --git a/kernel/module.c b/kernel/module.c
index 0925c9a..cfd4a3f 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1209,7 +1209,7 @@ static inline int check_modstruct_version(Elf_Shdr *sechdrs,
/* Since this should be found in kernel (which can't be removed),
* no locking is necessary. */
- if (!find_symbol(MODULE_SYMBOL_PREFIX "module_layout", NULL,
+ if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
&crc, true, false))
BUG();
return check_version(sechdrs, versindex, "module_layout", mod, crc,
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 07125e6..a373a1f 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -119,13 +119,6 @@ _c_flags += $(if $(patsubst n%,, \
$(CFLAGS_GCOV))
endif
-ifdef CONFIG_SYMBOL_PREFIX
-_sym_flags = -DSYMBOL_PREFIX=$(patsubst "%",%,$(CONFIG_SYMBOL_PREFIX))
-_cpp_flags += $(_sym_flags)
-_a_flags += $(_sym_flags)
-endif
-
-
# If building the kernel in a separate objtree expand all occurrences
# of -Idir to -I$(srctree)/dir except for absolute paths (starting with '/').
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index 3d569d6..0149949 100644
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -74,9 +74,8 @@ kallsyms()
info KSYM ${2}
local kallsymopt;
- if [ -n "${CONFIG_SYMBOL_PREFIX}" ]; then
- kallsymopt="${kallsymopt} \
- --symbol-prefix=${CONFIG_SYMBOL_PREFIX}"
+ if [ -n "${CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX}" ]; then
+ kallsymopt="${kallsymopt} --symbol-prefix=_"
fi
if [ -n "${CONFIG_KALLSYMS_ALL}" ]; then
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 78b30c1..282decf 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -18,14 +18,7 @@
#include "modpost.h"
#include "../../include/generated/autoconf.h"
#include "../../include/linux/license.h"
-
-/* Some toolchains use a `_' prefix for all user symbols. */
-#ifdef CONFIG_SYMBOL_PREFIX
-#define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
-#else
-#define MODULE_SYMBOL_PREFIX ""
-#endif
-
+#include "../../include/linux/export.h"
/* Are we using CONFIG_MODVERSIONS? */
int modversions = 0;
@@ -562,7 +555,7 @@ static void parse_elf_finish(struct elf_info *info)
static int ignore_undef_symbol(struct elf_info *info, const char *symname)
{
/* ignore __this_module, it will be resolved shortly */
- if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0)
+ if (strcmp(symname, VMLINUX_SYMBOL_STR(__this_module)) == 0)
return 1;
/* ignore global offset table */
if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
@@ -583,8 +576,8 @@ static int ignore_undef_symbol(struct elf_info *info, const char *symname)
return 0;
}
-#define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_"
-#define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
+#define CRC_PFX VMLINUX_SYMBOL_STR(__crc_)
+#define KSYMTAB_PFX VMLINUX_SYMBOL_STR(__ksymtab_)
static void handle_modversions(struct module *mod, struct elf_info *info,
Elf_Sym *sym, const char *symname)
@@ -637,14 +630,15 @@ static void handle_modversions(struct module *mod, struct elf_info *info,
}
#endif
- if (memcmp(symname, MODULE_SYMBOL_PREFIX,
- strlen(MODULE_SYMBOL_PREFIX)) == 0) {
- mod->unres =
- alloc_symbol(symname +
- strlen(MODULE_SYMBOL_PREFIX),
- ELF_ST_BIND(sym->st_info) == STB_WEAK,
- mod->unres);
- }
+#ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
+ if (symname[0] != '_')
+ break;
+ else
+ symname++;
+#endif
+ mod->unres = alloc_symbol(symname,
+ ELF_ST_BIND(sym->st_info) == STB_WEAK,
+ mod->unres);
break;
default:
/* All exported symbols */
@@ -652,9 +646,9 @@ static void handle_modversions(struct module *mod, struct elf_info *info,
sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
export);
}
- if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0)
+ if (strcmp(symname, VMLINUX_SYMBOL_STR(init_module)) == 0)
mod->has_init = 1;
- if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0)
+ if (strcmp(symname, VMLINUX_SYMBOL_STR(cleanup_module)) == 0)
mod->has_cleanup = 1;
break;
}
On 14/03/13 04:00, Rusty Russell wrote:
> From: Rusty Russell <[email protected]>
> Subject: CONFIG_SYMBOL_PREFIX: cleanup.
>
> We have CONFIG_SYMBOL_PREFIX, which three archs define to the string
> "_". But Al Viro broke this in "consolidate cond_syscall and
> SYSCALL_ALIAS declarations" (in linux-next), and he's not the first to
> do so.
>
> Using CONFIG_SYMBOL_PREFIX is awkward, since we usually just want to
> prefix it so something. So various places define helpers which are
> defined to nothing if CONFIG_SYMBOL_PREFIX isn't set:
>
> 1) include/asm-generic/unistd.h defines __SYMBOL_PREFIX.
> 2) include/asm-generic/vmlinux.lds.h defines VMLINUX_SYMBOL(sym)
> 3) include/linux/export.h defines MODULE_SYMBOL_PREFIX.
> 4) include/linux/kernel.h defines SYMBOL_PREFIX (which differs from #7)
> 5) kernel/modsign_certificate.S defines ASM_SYMBOL(sym)
> 6) scripts/modpost.c defines MODULE_SYMBOL_PREFIX
> 7) scripts/Makefile.lib defines SYMBOL_PREFIX on the commandline if
> CONFIG_SYMBOL_PREFIX is set, so that we have a non-string version
> for pasting.
>
> (arch/h8300/include/asm/linkage.h defines SYMBOL_NAME(), too).
>
> Let's solve this properly:
> 1) No more generic prefix, just CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX.
> 2) Make linux/export.h usable from asm.
> 3) Define VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR().
> 4) Make everyone use them.
>
> Signed-off-by: Rusty Russell <[email protected]>
Reviewed-by: James Hogan <[email protected]>
Tested-by: James Hogan <[email protected]> (metag)
The only other special case of symbol prefixing I'm aware of is in
scripts/genksyms/genksyms.c. It makes the decision at runtime based
on the --arch=$ARCH argument, and is the only use of the arch argument:
> if ((strcmp(arch, "h8300") == 0) || (strcmp(arch, "blackfin") == 0) ||
> (strcmp(arch, "metag") == 0))
> mod_prefix = "_";
Does the patch below look reasonable in addition to your patch?
(Note: I'm not sure if genksyms is only used internally or whether
it's API should be kept stable?).
Thanks
James
Subject: [PATCH] genksyms: pass symbol-prefix instead of arch
Pass symbol-prefix to genksyms instead of arch, so that the decision
what symbol prefix to use is kept in one place.
Basically genksyms used to take a -a $ARCH argument and it used that to
determine whether to add an underscore symbol prefix. It's now changed
to take a -s $SYMBOL_PREFIX argument so that the caller decides whether
a symbol prefix is required. The build system then uses
CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX to determine whether to pass the
argument.
Signed-off-by: James Hogan <[email protected]>
---
scripts/Makefile.build | 3 ++-
scripts/genksyms/genksyms.c | 18 +++++++-----------
2 files changed, 9 insertions(+), 12 deletions(-)
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 0e801c3..d5d859c 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -211,7 +211,8 @@ $(obj)/%.i: $(src)/%.c FORCE
cmd_gensymtypes = \
$(CPP) -D__GENKSYMS__ $(c_flags) $< | \
- $(GENKSYMS) $(if $(1), -T $(2)) -a $(ARCH) \
+ $(GENKSYMS) $(if $(1), -T $(2)) \
+ $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX)) \
$(if $(KBUILD_PRESERVE),-p) \
-r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
diff --git a/scripts/genksyms/genksyms.c b/scripts/genksyms/genksyms.c
index d25e4a1..88632df 100644
--- a/scripts/genksyms/genksyms.c
+++ b/scripts/genksyms/genksyms.c
@@ -45,7 +45,6 @@ int in_source_file;
static int flag_debug, flag_dump_defs, flag_reference, flag_dump_types,
flag_preserve, flag_warnings;
-static const char *arch = "";
static const char *mod_prefix = "";
static int errors;
@@ -731,7 +730,7 @@ static void genksyms_usage(void)
{
fputs("Usage:\n" "genksyms [-adDTwqhV] > /path/to/.tmp_obj.ver\n" "\n"
#ifdef __GNU_LIBRARY__
- " -a, --arch Select architecture\n"
+ " -s, --symbol-prefix Select symbol prefix\n"
" -d, --debug Increment the debug level (repeatable)\n"
" -D, --dump Dump expanded symbol defs (for debugging only)\n"
" -r, --reference file Read reference symbols from a file\n"
@@ -742,7 +741,7 @@ static void genksyms_usage(void)
" -h, --help Print this message\n"
" -V, --version Print the release version\n"
#else /* __GNU_LIBRARY__ */
- " -a Select architecture\n"
+ " -s Select symbol prefix\n"
" -d Increment the debug level (repeatable)\n"
" -D Dump expanded symbol defs (for debugging only)\n"
" -r file Read reference symbols from a file\n"
@@ -763,7 +762,7 @@ int main(int argc, char **argv)
#ifdef __GNU_LIBRARY__
struct option long_opts[] = {
- {"arch", 1, 0, 'a'},
+ {"symbol-prefix", 1, 0, 's'},
{"debug", 0, 0, 'd'},
{"warnings", 0, 0, 'w'},
{"quiet", 0, 0, 'q'},
@@ -776,14 +775,14 @@ int main(int argc, char **argv)
{0, 0, 0, 0}
};
- while ((o = getopt_long(argc, argv, "a:dwqVDr:T:ph",
+ while ((o = getopt_long(argc, argv, "s:dwqVDr:T:ph",
&long_opts[0], NULL)) != EOF)
#else /* __GNU_LIBRARY__ */
- while ((o = getopt(argc, argv, "a:dwqVDr:T:ph")) != EOF)
+ while ((o = getopt(argc, argv, "s:dwqVDr:T:ph")) != EOF)
#endif /* __GNU_LIBRARY__ */
switch (o) {
- case 'a':
- arch = optarg;
+ case 's':
+ mod_prefix = optarg;
break;
case 'd':
flag_debug++;
@@ -826,9 +825,6 @@ int main(int argc, char **argv)
genksyms_usage();
return 1;
}
- if ((strcmp(arch, "h8300") == 0) || (strcmp(arch, "blackfin") == 0) ||
- (strcmp(arch, "metag") == 0))
- mod_prefix = "_";
{
extern int yydebug;
extern int yy_flex_debug;
--
1.8.1.2
James Hogan <[email protected]> writes:
> On 14/03/13 04:00, Rusty Russell wrote:
>> From: Rusty Russell <[email protected]>
>> Subject: CONFIG_SYMBOL_PREFIX: cleanup.
...
> Reviewed-by: James Hogan <[email protected]>
> Tested-by: James Hogan <[email protected]> (metag)
Thanks.
> The only other special case of symbol prefixing I'm aware of is in
> scripts/genksyms/genksyms.c. It makes the decision at runtime based
> on the --arch=$ARCH argument, and is the only use of the arch argument:
>
>> if ((strcmp(arch, "h8300") == 0) || (strcmp(arch, "blackfin") == 0) ||
>> (strcmp(arch, "metag") == 0))
>> mod_prefix = "_";
>
> Does the patch below look reasonable in addition to your patch?
> (Note: I'm not sure if genksyms is only used internally or whether
> it's API should be kept stable?).
>
> Thanks
> James
>
> Subject: [PATCH] genksyms: pass symbol-prefix instead of arch
Agreed, I've applied this.
Thanks,
Rusty.