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Groups > linux.kernel > #1403536
| From | tip-bot for Josh Poimboeuf <tipbot@zytor.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [tip:x86/urgent] x86/entry/64: Fix stack return address retrieval in thunk |
| Date | 2016-05-19 11:20 +0200 |
| Message-ID | <rAshz-6ee-21@gated-at.bofh.it> (permalink) |
| References | <rzRBo-7V2-9@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
Commit-ID: d4bf7078c43e11097e0d6f04d3fb999bf92c4fb0
Gitweb: http://git.kernel.org/tip/d4bf7078c43e11097e0d6f04d3fb999bf92c4fb0
Author: Josh Poimboeuf <jpoimboe@redhat.com>
AuthorDate: Tue, 17 May 2016 13:06:06 -0500
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 19 May 2016 09:12:34 +0200
x86/entry/64: Fix stack return address retrieval in thunk
With CONFIG_FRAME_POINTER enabled, a thunk can pass a bad return address
value to the called function. '9*8(%rsp)' actually gets the frame
pointer, not the return address.
The only users of the 'put_ret_addr_in_rdi' option are two functions
which trace the enabling and disabling of interrupts, so this bug can
result in bad debug or tracing information with CONFIG_IRQSOFF_TRACER or
CONFIG_PROVE_LOCKING.
Fix this by implementing the suggestion of Linus: explicitly push
the frame pointer all the time and constify the stack offsets that
way. This is both correct and easier to read.
Reported-by: Matt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
[ Extended the changelog a bit. ]
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Alex Thorlton <athorlton@sgi.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 058fb73274f9 ("x86/asm/entry: Create stack frames in thunk functions")
Link: http://lkml.kernel.org/r/20160517180606.v5o7wcgdni7443ol@treble
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/entry/thunk_64.S | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)
diff --git a/arch/x86/entry/thunk_64.S b/arch/x86/entry/thunk_64.S
index 98df1fa..027aec4 100644
--- a/arch/x86/entry/thunk_64.S
+++ b/arch/x86/entry/thunk_64.S
@@ -8,16 +8,15 @@
#include <linux/linkage.h>
#include "calling.h"
#include <asm/asm.h>
-#include <asm/frame.h>
/* rdi: arg1 ... normal C conventions. rax is saved/restored. */
.macro THUNK name, func, put_ret_addr_in_rdi=0
.globl \name
.type \name, @function
\name:
- FRAME_BEGIN
+ pushq %rbp
+ movq %rsp, %rbp
- /* this one pushes 9 elems, the next one would be %rIP */
pushq %rdi
pushq %rsi
pushq %rdx
@@ -29,8 +28,8 @@
pushq %r11
.if \put_ret_addr_in_rdi
- /* 9*8(%rsp) is return addr on stack */
- movq 9*8(%rsp), %rdi
+ /* 8(%rbp) is return addr on stack */
+ movq 8(%rbp), %rdi
.endif
call \func
@@ -65,7 +64,7 @@ restore:
popq %rdx
popq %rsi
popq %rdi
- FRAME_END
+ popq %rbp
ret
_ASM_NOKPROBE(restore)
#endif
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[GIT PULL] EFI fix Ingo Molnar <mingo@kernel.org> - 2016-05-16 16:50 +0200
Re: [GIT PULL] EFI fix Linus Torvalds <torvalds@linux-foundation.org> - 2016-05-16 22:10 +0200
Re: [GIT PULL] EFI fix Alex Thorlton <athorlton@sgi.com> - 2016-05-16 22:30 +0200
Re: [GIT PULL] EFI fix Alex Thorlton <athorlton@sgi.com> - 2016-05-17 00:50 +0200
[tip:x86/urgent] x86/efi: Fix 7-parameter efi_call()s tip-bot for Linus Torvalds <tipbot@zytor.com> - 2016-05-17 08:40 +0200
Re: [GIT PULL] EFI fix Matt Fleming <matt@codeblueprint.co.uk> - 2016-05-17 11:10 +0200
Re: [GIT PULL] EFI fix Matt Fleming <matt@codeblueprint.co.uk> - 2016-05-17 11:50 +0200
Re: [GIT PULL] EFI fix Ingo Molnar <mingo@kernel.org> - 2016-05-17 12:30 +0200
[PATCH] x86/asm/entry: fix stack return address retrieval in thunk Josh Poimboeuf <jpoimboe@redhat.com> - 2016-05-17 16:50 +0200
Re: [PATCH] x86/asm/entry: fix stack return address retrieval in thunk Linus Torvalds <torvalds@linux-foundation.org> - 2016-05-17 18:40 +0200
Re: [PATCH] x86/asm/entry: fix stack return address retrieval in thunk Steven Rostedt <rostedt@goodmis.org> - 2016-05-17 19:00 +0200
Re: [PATCH] x86/asm/entry: fix stack return address retrieval in thunk Linus Torvalds <torvalds@linux-foundation.org> - 2016-05-17 19:30 +0200
Re: [PATCH] x86/asm/entry: fix stack return address retrieval in thunk Josh Poimboeuf <jpoimboe@redhat.com> - 2016-05-17 19:30 +0200
[PATCH v2] x86/asm/entry: fix stack return address retrieval in thunk Josh Poimboeuf <jpoimboe@redhat.com> - 2016-05-17 20:10 +0200
Re: [PATCH v2] x86/asm/entry: fix stack return address retrieval in thunk Linus Torvalds <torvalds@linux-foundation.org> - 2016-05-17 20:40 +0200
[tip:x86/urgent] x86/entry/64: Fix stack return address retrieval in thunk tip-bot for Josh Poimboeuf <tipbot@zytor.com> - 2016-05-19 11:20 +0200
Re: [GIT PULL] EFI fix Matt Fleming <matt@codeblueprint.co.uk> - 2016-05-23 14:10 +0200
Re: [GIT PULL] EFI fix Josh Poimboeuf <jpoimboe@redhat.com> - 2016-05-23 14:40 +0200
Re: [GIT PULL] EFI fix Ingo Molnar <mingo@kernel.org> - 2016-05-24 11:10 +0200
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