Commit 058fb732 authored Jan 21, 2016 by Josh Poimboeuf Committed by Ingo Molnar Feb 24, 2016

x86/asm/entry: Create stack frames in thunk functions



Thunk functions are callable non-leaf functions that don't honor
CONFIG_FRAME_POINTER, which can result in bad stack traces.  Also they
aren't annotated as ELF callable functions which can confuse tooling.

Create stack frames for them when CONFIG_FRAME_POINTER is enabled and
add the ELF function type.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Chris J Arges <chris.j.arges@canonical.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Pedro Alves <palves@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: live-patching@vger.kernel.org
Link: http://lkml.kernel.org/r/4373e5bff459b9fd66ce5d45bfcc881a5c202643.1453405861.git.jpoimboe@redhat.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent 8691ccd7

arch/x86/entry/thunk_64.S

+4 −0

Original line number	Original line	Diff line number	Diff line
	@@ -8,11 +8,14 @@
	#include <linux/linkage.h>		#include <linux/linkage.h>
	#include "calling.h"		#include "calling.h"
	#include <asm/asm.h>		#include <asm/asm.h>
			#include <asm/frame.h>

	/* rdi: arg1 ... normal C conventions. rax is saved/restored. */		/* rdi: arg1 ... normal C conventions. rax is saved/restored. */
	.macro THUNK name, func, put_ret_addr_in_rdi=0		.macro THUNK name, func, put_ret_addr_in_rdi=0
	.globl \name		.globl \name
			.type \name, @function
	\name:		\name:
			FRAME_BEGIN

	/* this one pushes 9 elems, the next one would be %rIP */		/* this one pushes 9 elems, the next one would be %rIP */
	pushq %rdi		pushq %rdi
	@@ -62,6 +65,7 @@ restore:
	popq %rdx		popq %rdx
	popq %rsi		popq %rsi
	popq %rdi		popq %rdi
			FRAME_END
	ret		ret
	_ASM_NOKPROBE(restore)		_ASM_NOKPROBE(restore)
	#endif		#endif