[PATCH] x86/asm/entry/64: Add forgotten CFI annotation

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* [PATCH] x86/asm/entry/64: Add forgotten CFI annotation
@ 2015-04-07 16:42 Denys Vlasenko
  2015-04-08  7:18 ` Ingo Molnar
  2015-04-08  7:43 ` [tip:x86/asm] " tip-bot for Denys Vlasenko
  0 siblings, 2 replies; 3+ messages in thread
From: Denys Vlasenko @ 2015-04-07 16:42 UTC (permalink / raw)
  To: Ingo Molnar
  Cc: Denys Vlasenko, Linus Torvalds, Steven Rostedt, Borislav Petkov,
	H. Peter Anvin, Andy Lutomirski, Oleg Nesterov,
	Frederic Weisbecker, Alexei Starovoitov, Will Drewry, Kees Cook,
	x86, linux-kernel

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
CC: Linus Torvalds <torvalds@linux-foundation.org>
CC: Steven Rostedt <rostedt@goodmis.org>
CC: Ingo Molnar <mingo@kernel.org>
CC: Borislav Petkov <bp@alien8.de>
CC: "H. Peter Anvin" <hpa@zytor.com>
CC: Andy Lutomirski <luto@amacapital.net>
CC: Oleg Nesterov <oleg@redhat.com>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Alexei Starovoitov <ast@plumgrid.com>
CC: Will Drewry <wad@chromium.org>
CC: Kees Cook <keescook@chromium.org>
CC: x86@kernel.org
CC: linux-kernel@vger.kernel.org
---
 arch/x86/kernel/entry_64.S | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 65485b3..15261ba 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -429,6 +429,7 @@ return_from_execve:
 1:
 	/* must use IRET code path (pt_regs->cs may have changed) */
 	addq	$8, %rsp
+	CFI_ADJUST_CFA_OFFSET -8
 	ZERO_EXTRA_REGS
 	movq	%rax,RAX(%rsp)
 	jmp	int_ret_from_sys_call
-- 
1.8.1.4


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH] x86/asm/entry/64: Add forgotten CFI annotation
  2015-04-07 16:42 [PATCH] x86/asm/entry/64: Add forgotten CFI annotation Denys Vlasenko
@ 2015-04-08  7:18 ` Ingo Molnar
  2015-04-08  7:43 ` [tip:x86/asm] " tip-bot for Denys Vlasenko
  1 sibling, 0 replies; 3+ messages in thread
From: Ingo Molnar @ 2015-04-08  7:18 UTC (permalink / raw)
  To: Denys Vlasenko
  Cc: Linus Torvalds, Steven Rostedt, Borislav Petkov, H. Peter Anvin,
	Andy Lutomirski, Oleg Nesterov, Frederic Weisbecker,
	Alexei Starovoitov, Will Drewry, Kees Cook, x86, linux-kernel


* Denys Vlasenko <dvlasenk@redhat.com> wrote:

> Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
> CC: Linus Torvalds <torvalds@linux-foundation.org>
> CC: Steven Rostedt <rostedt@goodmis.org>
> CC: Ingo Molnar <mingo@kernel.org>
> CC: Borislav Petkov <bp@alien8.de>
> CC: "H. Peter Anvin" <hpa@zytor.com>
> CC: Andy Lutomirski <luto@amacapital.net>
> CC: Oleg Nesterov <oleg@redhat.com>
> CC: Frederic Weisbecker <fweisbec@gmail.com>
> CC: Alexei Starovoitov <ast@plumgrid.com>
> CC: Will Drewry <wad@chromium.org>
> CC: Kees Cook <keescook@chromium.org>
> CC: x86@kernel.org
> CC: linux-kernel@vger.kernel.org
> ---
>  arch/x86/kernel/entry_64.S | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
> index 65485b3..15261ba 100644
> --- a/arch/x86/kernel/entry_64.S
> +++ b/arch/x86/kernel/entry_64.S
> @@ -429,6 +429,7 @@ return_from_execve:
>  1:
>  	/* must use IRET code path (pt_regs->cs may have changed) */
>  	addq	$8, %rsp
> +	CFI_ADJUST_CFA_OFFSET -8
>  	ZERO_EXTRA_REGS
>  	movq	%rax,RAX(%rsp)
>  	jmp	int_ret_from_sys_call

So given that this is a pretty common pattern:

triton:~/tip> git grep -A 1 'addq.*%rsp' arch/x86/kernel/entry_64.S
arch/x86/kernel/entry_64.S:     addq    $8, %rsp
arch/x86/kernel/entry_64.S-     CFI_ADJUST_CFA_OFFSET -8
--
arch/x86/kernel/entry_64.S:     addq $8, %rsp
arch/x86/kernel/entry_64.S-     DEFAULT_FRAME 0
--
arch/x86/kernel/entry_64.S:     addq $8, %rsp
arch/x86/kernel/entry_64.S-     DEFAULT_FRAME 0
--
arch/x86/kernel/entry_64.S:     addq $-0x80,(%rsp)              /* Adjust vector to [-256,-1] range */
arch/x86/kernel/entry_64.S-     interrupt do_IRQ
--
arch/x86/kernel/entry_64.S:     addq $0x30,%rsp
arch/x86/kernel/entry_64.S-     CFI_ADJUST_CFA_OFFSET -0x30
--
arch/x86/kernel/entry_64.S:     addq $0x30,%rsp
arch/x86/kernel/entry_64.S-     CFI_ADJUST_CFA_OFFSET -0x30
--
arch/x86/kernel/entry_64.S:     addq $(6*8), %rsp
arch/x86/kernel/entry_64.S-     CFI_ADJUST_CFA_OFFSET -6*8
--
arch/x86/kernel/entry_64.S:     addq $(10*8), %rsp
arch/x86/kernel/entry_64.S-     CFI_ADJUST_CFA_OFFSET -10*8


it might make sense to introduce addq_cfi, to further hide the dwarf 
uglies?

btw., doesn't:

arch/x86/kernel/entry_64.S:     addq $-0x80,(%rsp)              /* Adjust vector to [-256,-1] range */

before the do_IRQ() call need a CFI adjustment as well?

Thanks,

	Ingo

^ permalink raw reply	[flat|nested] 3+ messages in thread

* [tip:x86/asm] x86/asm/entry/64: Add forgotten CFI annotation
  2015-04-07 16:42 [PATCH] x86/asm/entry/64: Add forgotten CFI annotation Denys Vlasenko
  2015-04-08  7:18 ` Ingo Molnar
@ 2015-04-08  7:43 ` tip-bot for Denys Vlasenko
  1 sibling, 0 replies; 3+ messages in thread
From: tip-bot for Denys Vlasenko @ 2015-04-08  7:43 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: mingo, wad, tglx, brgerst, ast, rostedt, keescook, luto, fweisbec,
	hpa, bp, linux-kernel, dvlasenk, torvalds, oleg

Commit-ID:  8b3607b5b8c591d8bf045911cb7c90ecaa6e7b73
Gitweb:     http://git.kernel.org/tip/8b3607b5b8c591d8bf045911cb7c90ecaa6e7b73
Author:     Denys Vlasenko <dvlasenk@redhat.com>
AuthorDate: Tue, 7 Apr 2015 18:42:47 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Wed, 8 Apr 2015 09:18:36 +0200

x86/asm/entry/64: Add forgotten CFI annotation

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/1428424967-14460-1-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/kernel/entry_64.S | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 4ca03c5..3197f41 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -506,6 +506,7 @@ return_from_execve:
 1:
 	/* must use IRET code path (pt_regs->cs may have changed) */
 	addq	$8, %rsp
+	CFI_ADJUST_CFA_OFFSET -8
 	ZERO_EXTRA_REGS
 	movq	%rax,RAX(%rsp)
 	jmp	int_ret_from_sys_call

^ permalink raw reply related	[flat|nested] 3+ messages in thread

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2015-04-07 16:42 [PATCH] x86/asm/entry/64: Add forgotten CFI annotation Denys Vlasenko
2015-04-08  7:18 ` Ingo Molnar
2015-04-08  7:43 ` [tip:x86/asm] " tip-bot for Denys Vlasenko

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