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authorDenys Vlasenko <dvlasenk@redhat.com>2015-04-07 22:43:44 +0200
committerIngo Molnar <mingo@kernel.org>2015-04-09 10:31:26 +0200
commita37f34a325d90856314ccd4994e1070dcc6bdcc4 (patch)
tree9761bec624da40a90c0dfd7b2732fbdd8c9cdec2 /arch/x86/kernel/entry_64.S
parent54a81e914b2432a86dd49cf611b0f71ef44ca7ad (diff)
downloadop-kernel-dev-a37f34a325d90856314ccd4994e1070dcc6bdcc4.zip
op-kernel-dev-a37f34a325d90856314ccd4994e1070dcc6bdcc4.tar.gz
x86/asm/entry/64: Reduce padding in execve stubs
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>
Diffstat (limited to 'arch/x86/kernel/entry_64.S')
-rw-r--r--arch/x86/kernel/entry_64.S20
1 files changed, 14 insertions, 6 deletions
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index b67f2fc..c7b2384 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -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
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