* [PATCH] Use gcc alias instead of assembler aliases for syscalls
@ 2013-08-05 22:09 Andi Kleen
2013-08-06 5:59 ` Andrew Morton
2013-08-07 23:54 ` Andrew Morton
0 siblings, 2 replies; 6+ messages in thread
From: Andi Kleen @ 2013-08-05 22:09 UTC (permalink / raw)
To: viro; +Cc: linux-kernel, Andi Kleen
From: Andi Kleen <ak@linux.intel.com>
Use standard gcc __attribute__((alias(foo))) to define
the syscall aliases instead of custom assembler macros.
This is far cleaner, and also fixes my LTO kernel build.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
---
include/linux/compat.h | 4 ++--
include/linux/syscalls.h | 4 ++--
2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/include/linux/compat.h b/include/linux/compat.h
index 7f0c1dd..18e4b75 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -41,13 +41,13 @@
COMPAT_SYSCALL_DEFINEx(6, _##name, __VA_ARGS__)
#define COMPAT_SYSCALL_DEFINEx(x, name, ...) \
- asmlinkage long compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__));\
+ asmlinkage long compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))\
+ __attribute__((alias(__stringify(compat_SyS##name)))); \
static inline long C_SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__));\
asmlinkage long compat_SyS##name(__MAP(x,__SC_LONG,__VA_ARGS__))\
{ \
return C_SYSC##name(__MAP(x,__SC_DELOUSE,__VA_ARGS__)); \
} \
- SYSCALL_ALIAS(compat_sys##name, compat_SyS##name); \
static inline long C_SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__))
#ifndef compat_user_stack_pointer
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 4147d70..87039ad 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -184,7 +184,8 @@ extern struct trace_event_functions exit_syscall_print_funcs;
#define __PROTECT(...) asmlinkage_protect(__VA_ARGS__)
#define __SYSCALL_DEFINEx(x, name, ...) \
- asmlinkage long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \
+ asmlinkage long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) \
+ __attribute__((alias(__stringify(SyS##name)))); \
static inline long SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \
asmlinkage long SyS##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \
{ \
@@ -193,7 +194,6 @@ extern struct trace_event_functions exit_syscall_print_funcs;
__PROTECT(x, ret,__MAP(x,__SC_ARGS,__VA_ARGS__)); \
return ret; \
} \
- SYSCALL_ALIAS(sys##name, SyS##name); \
static inline long SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__))
asmlinkage long sys_time(time_t __user *tloc);
--
1.8.3.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] Use gcc alias instead of assembler aliases for syscalls
2013-08-05 22:09 [PATCH] Use gcc alias instead of assembler aliases for syscalls Andi Kleen
@ 2013-08-06 5:59 ` Andrew Morton
2013-08-06 6:42 ` Andi Kleen
2013-08-07 23:54 ` Andrew Morton
1 sibling, 1 reply; 6+ messages in thread
From: Andrew Morton @ 2013-08-06 5:59 UTC (permalink / raw)
To: Andi Kleen; +Cc: viro, linux-kernel, Andi Kleen
On Mon, 5 Aug 2013 15:09:35 -0700 Andi Kleen <andi@firstfloor.org> wrote:
> From: Andi Kleen <ak@linux.intel.com>
>
> Use standard gcc __attribute__((alias(foo))) to define
> the syscall aliases instead of custom assembler macros.
>
> This is far cleaner, and also fixes my LTO kernel build.
I wonder what gcc version this was added in. Seems fairly longstanding.
> { \
> return C_SYSC##name(__MAP(x,__SC_DELOUSE,__VA_ARGS__)); \
> } \
> - SYSCALL_ALIAS(compat_sys##name, compat_SyS##name); \
I think we can remove the SYSCALL_ALIAS definitions?
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] Use gcc alias instead of assembler aliases for syscalls
2013-08-06 5:59 ` Andrew Morton
@ 2013-08-06 6:42 ` Andi Kleen
2013-08-06 7:40 ` Al Viro
0 siblings, 1 reply; 6+ messages in thread
From: Andi Kleen @ 2013-08-06 6:42 UTC (permalink / raw)
To: Andrew Morton; +Cc: Andi Kleen, viro, linux-kernel, Andi Kleen
On Mon, Aug 05, 2013 at 10:59:49PM -0700, Andrew Morton wrote:
> On Mon, 5 Aug 2013 15:09:35 -0700 Andi Kleen <andi@firstfloor.org> wrote:
>
> > From: Andi Kleen <ak@linux.intel.com>
> >
> > Use standard gcc __attribute__((alias(foo))) to define
> > the syscall aliases instead of custom assembler macros.
> >
> > This is far cleaner, and also fixes my LTO kernel build.
>
> I wonder what gcc version this was added in. Seems fairly longstanding.
Seems to be already in 2.95, so every kernel compiler
http://gcc.gnu.org/onlinedocs/gcc-2.95.3/gcc_4.html#SEC90
>
> > { \
> > return C_SYSC##name(__MAP(x,__SC_DELOUSE,__VA_ARGS__)); \
> > } \
> > - SYSCALL_ALIAS(compat_sys##name, compat_SyS##name); \
>
> I think we can remove the SYSCALL_ALIAS definitions?
Yes will send a followon patch.
-Andi
--
ak@linux.intel.com -- Speaking for myself only.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] Use gcc alias instead of assembler aliases for syscalls
2013-08-06 6:42 ` Andi Kleen
@ 2013-08-06 7:40 ` Al Viro
0 siblings, 0 replies; 6+ messages in thread
From: Al Viro @ 2013-08-06 7:40 UTC (permalink / raw)
To: Andi Kleen; +Cc: Andrew Morton, linux-kernel, Andi Kleen, Geert Uytterhoeven
On Tue, Aug 06, 2013 at 08:42:01AM +0200, Andi Kleen wrote:
> On Mon, Aug 05, 2013 at 10:59:49PM -0700, Andrew Morton wrote:
> > On Mon, 5 Aug 2013 15:09:35 -0700 Andi Kleen <andi@firstfloor.org> wrote:
> >
> > > From: Andi Kleen <ak@linux.intel.com>
> > >
> > > Use standard gcc __attribute__((alias(foo))) to define
> > > the syscall aliases instead of custom assembler macros.
> > >
> > > This is far cleaner, and also fixes my LTO kernel build.
> >
> > I wonder what gcc version this was added in. Seems fairly longstanding.
>
> Seems to be already in 2.95, so every kernel compiler
IIRC, there had been some architectures where it didn't work correctly.
I don't remember details, though... Geert?
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] Use gcc alias instead of assembler aliases for syscalls
2013-08-05 22:09 [PATCH] Use gcc alias instead of assembler aliases for syscalls Andi Kleen
2013-08-06 5:59 ` Andrew Morton
@ 2013-08-07 23:54 ` Andrew Morton
2013-08-08 4:39 ` Andi Kleen
1 sibling, 1 reply; 6+ messages in thread
From: Andrew Morton @ 2013-08-07 23:54 UTC (permalink / raw)
To: Andi Kleen; +Cc: viro, linux-kernel, Andi Kleen
On Mon, 5 Aug 2013 15:09:35 -0700 Andi Kleen <andi@firstfloor.org> wrote:
> From: Andi Kleen <ak@linux.intel.com>
>
> Use standard gcc __attribute__((alias(foo))) to define
> the syscall aliases instead of custom assembler macros.
>
> This is far cleaner, and also fixes my LTO kernel build.
>
This makes my x86_64 allmodconfig build emit screenfuls of
...
WARNING: "alloc_pages_current" [drivers/block/brd.ko] has no CRC!
WARNING: "alloc_pages_current" [drivers/base/firmware_class.ko] has no CRC!
WARNING: "schedule_timeout" [drivers/atm/solos-pci.ko] has no CRC!
WARNING: "schedule_timeout" [drivers/atm/iphase.ko] has no CRC!
WARNING: "schedule_timeout" [drivers/atm/he.ko] has no CRC!
WARNING: "schedule_timeout" [drivers/acpi/sbshc.ko] has no CRC!
WARNING: "schedule_timeout" [drivers/acpi/acpi_ipmi.ko] has no CRC!
WARNING: "alloc_pages_current" [crypto/async_tx/raid6test.ko] has no CRC!
WARNING: "alloc_pages_current" [crypto/async_tx/async_pq.ko] has no CRC!
WARNING: "alloc_pages_current" [crypto/algif_skcipher.ko] has no CRC!
WARNING: "schedule_timeout" [crypto/algif_skcipher.ko] has no CRC!
WARNING: "sock_register" [crypto/af_alg.ko] has no CRC!
WARNING: "task_nice" [block/cfq-iosched.ko] has no CRC!
WARNING: "perf_event_create_kernel_counter" [arch/x86/oprofile/oprofile.ko] has no CRC!
WARNING: "alloc_pages_current" [arch/x86/kvm/kvm.ko] has no CRC!
WARNING: "perf_event_create_kernel_counter" [arch/x86/kvm/kvm.ko] has no CRC!
WARNING: "alloc_pages_current" [arch/x86/kvm/kvm-amd.ko] has no CRC!
WARNING: "schedule_timeout" [arch/x86/kernel/cpu/mcheck/mce-inject.ko] has no CRC!
WARNING: "schedule_timeout" [arch/x86/kernel/apm.ko] has no CRC!
make[1]: *** [__modpost] Error 1
make: *** [modules] Error 2
Unexpected, but I checked it a couple of times.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] Use gcc alias instead of assembler aliases for syscalls
2013-08-07 23:54 ` Andrew Morton
@ 2013-08-08 4:39 ` Andi Kleen
0 siblings, 0 replies; 6+ messages in thread
From: Andi Kleen @ 2013-08-08 4:39 UTC (permalink / raw)
To: Andrew Morton; +Cc: Andi Kleen, viro, linux-kernel
On Wed, Aug 07, 2013 at 04:54:21PM -0700, Andrew Morton wrote:
> On Mon, 5 Aug 2013 15:09:35 -0700 Andi Kleen <andi@firstfloor.org> wrote:
>
> > From: Andi Kleen <ak@linux.intel.com>
> >
> > Use standard gcc __attribute__((alias(foo))) to define
> > the syscall aliases instead of custom assembler macros.
> >
> > This is far cleaner, and also fixes my LTO kernel build.
> >
>
> This makes my x86_64 allmodconfig build emit screenfuls of
Ok I can reproduce with MODVERSIONS. Very mysterious, as I
didn't change EXPORT_SYMBOL. Will look into it.
Thanks.
-Andi
^ permalink raw reply [flat|nested] 6+ messages in thread
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2013-08-05 22:09 [PATCH] Use gcc alias instead of assembler aliases for syscalls Andi Kleen
2013-08-06 5:59 ` Andrew Morton
2013-08-06 6:42 ` Andi Kleen
2013-08-06 7:40 ` Al Viro
2013-08-07 23:54 ` Andrew Morton
2013-08-08 4:39 ` Andi Kleen
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