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 <dvlas...@redhat.com>
CC: Linus Torvalds <torva...@linux-foundation.org>
CC: Steven Rostedt <rost...@goodmis.org>
CC: Ingo Molnar <mi...@kernel.org>
CC: Borislav Petkov <b...@alien8.de>
CC: "H. Peter Anvin" <h...@zytor.com>
CC: Andy Lutomirski <l...@amacapital.net>
CC: Oleg Nesterov <o...@redhat.com>
CC: Frederic Weisbecker <fweis...@gmail.com>
CC: Alexei Starovoitov <a...@plumgrid.com>
CC: Will Drewry <w...@chromium.org>
CC: Kees Cook <keesc...@chromium.org>
CC: x...@kernel.org
CC: linux-kernel@vger.kernel.org
---
arch/x86/kernel/entry_64.S | 20 ++++++++++++++------
1 file changed, 14 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 05224d4..2aa3eca 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -434,8 +434,12 @@ 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
@@ -444,14 +448,16 @@ 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
@@ -461,13 +467,15 @@ 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
--
1.8.1.4
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