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x86/asm/entry/64: Reduce padding in execve stubs

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execve stubs are 7 bytes only. Padding them to 16 bytes is a
waste.

   text	   data	    bss	    dec	    hex	filename
  12594	      0	      0	  12594	   3132	entry_64.o.before
  12530	      0	      0	  12530	   30f2	entry_64.o

Run-tested.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1428439424-7258-8-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Denys Vlasenko 2015-04-07 22:43:44 +02:00 committed by Ingo Molnar
parent 54a81e914b
commit a37f34a325
1 changed files with 14 additions and 6 deletions
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20
arch/x86/kernel/entry_64.S
View file

@ -511,8 +511,12 @@ return_from_execve:
jmp int_ret_from_sys_call
CFI_ENDPROC
END(stub_execve)
ENTRY(stub_execveat)
/*
* Remaining execve stubs are only 7 bytes long.
* ENTRY() often aligns to 16 bytes, which in this case has no benefits.
*/
.align 8
GLOBAL(stub_execveat)
CFI_STARTPROC
DEFAULT_FRAME 0, 8
call sys_execveat
@ -521,14 +525,16 @@ ENTRY(stub_execveat)
END(stub_execveat)
#ifdef CONFIG_X86_X32_ABI
ENTRY(stub_x32_execve)
.align 8
GLOBAL(stub_x32_execve)
CFI_STARTPROC
DEFAULT_FRAME 0, 8
call compat_sys_execve
jmp return_from_execve
CFI_ENDPROC
END(stub_x32_execve)
ENTRY(stub_x32_execveat)
.align 8
GLOBAL(stub_x32_execveat)
CFI_STARTPROC
DEFAULT_FRAME 0, 8
call compat_sys_execveat
@ -538,13 +544,15 @@ END(stub_x32_execveat)
#endif
#ifdef CONFIG_IA32_EMULATION
ENTRY(stub32_execve)
.align 8
GLOBAL(stub32_execve)
CFI_STARTPROC
call compat_sys_execve
jmp return_from_execve
CFI_ENDPROC
END(stub32_execve)
ENTRY(stub32_execveat)
.align 8
GLOBAL(stub32_execveat)
CFI_STARTPROC
call compat_sys_execveat
jmp return_from_execve