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From: Steven Rostedt <rostedt@goodmis.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: tglx@linutronix.de, bp@alien8.de, mingo@kernel.org,
	luto@kernel.org, torvalds@linux-foundation.org, hpa@zytor.com,
	dave.hansen@linux.intel.com, jgross@suse.com,
	linux-kernel@vger.kernel.org, zhe.he@windriver.com,
	joel@joelfernandes.org, devel@etsukata.com
Subject: Re: [PATCH v2 2/7] x86/entry/32: Simplify common_exception
Date: Wed, 10 Jul 2019 16:11:37 -0400	[thread overview]
Message-ID: <20190710161137.026cdd47@gandalf.local.home> (raw)
In-Reply-To: <20190704200050.363747790@infradead.org>

On Thu, 04 Jul 2019 21:55:57 +0200
Peter Zijlstra <peterz@infradead.org> wrote:

> --- a/arch/x86/entry/entry_32.S
> +++ b/arch/x86/entry/entry_32.S
> @@ -294,9 +294,11 @@
>  .Lfinished_frame_\@:
>  .endm
>  
> -.macro SAVE_ALL pt_regs_ax=%eax switch_stacks=0
> +.macro SAVE_ALL pt_regs_ax=%eax switch_stacks=0 skip_gs=0
>  	cld
> +.if \skip_gs == 0
>  	PUSH_GS
> +.endif
>  	FIXUP_FRAME
>  	pushl	%fs
>  	pushl	%es
> @@ -313,13 +315,13 @@
>  	movl	%edx, %es
>  	movl	$(__KERNEL_PERCPU), %edx
>  	movl	%edx, %fs
> +.if \skip_gs == 0
>  	SET_KERNEL_GS %edx
> -
> +.endif
>  	/* Switch to kernel stack if necessary */
>  .if \switch_stacks > 0
>  	SWITCH_TO_KERNEL_STACK
>  .endif
> -
>  .endm
>  
>  .macro SAVE_ALL_NMI cr3_reg:req
> @@ -1448,32 +1450,20 @@ END(page_fault)
>  
>  common_exception:
>  	/* the function address is in %gs's slot on the stack */
> -	FIXUP_FRAME
> -	pushl	%fs
> -	pushl	%es
> -	pushl	%ds
> -	pushl	%eax
> -	movl	$(__USER_DS), %eax
> -	movl	%eax, %ds
> -	movl	%eax, %es
> -	movl	$(__KERNEL_PERCPU), %eax
> -	movl	%eax, %fs
> -	pushl	%ebp
> -	pushl	%edi
> -	pushl	%esi
> -	pushl	%edx
> -	pushl	%ecx
> -	pushl	%ebx
> -	SWITCH_TO_KERNEL_STACK
> +	SAVE_ALL switch_stacks=1 skip_gs=1
>  	ENCODE_FRAME_POINTER
> -	cld

The only code change of this is that cld moved from the end to the
beginning. As this appears to match other SAVE_ALL users with respect
to ENCODE_FRAME_POINTER, this shouldn't be an issue.

Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

-- Steve



>  	UNWIND_ESPFIX_STACK
> +

  parent reply	other threads:[~2019-07-10 20:11 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-04 19:55 [PATCH v2 0/7] Tracing vs CR2 (and cleanups) Peter Zijlstra
2019-07-04 19:55 ` [PATCH v2 1/7] x86/paravirt: Make read_cr2() CALLEE_SAVE Peter Zijlstra
2019-07-04 21:49   ` Andy Lutomirski
2019-07-10 19:53   ` Steven Rostedt
2019-07-04 19:55 ` [PATCH v2 2/7] x86/entry/32: Simplify common_exception Peter Zijlstra
2019-07-04 21:51   ` Andy Lutomirski
2019-07-10 20:11   ` Steven Rostedt [this message]
2019-07-10 20:14     ` Peter Zijlstra
2019-07-04 19:55 ` [PATCH v2 3/7] x86/entry/64: Simplify idtentry a little Peter Zijlstra
2019-07-04 21:54   ` Andy Lutomirski
2019-07-10 20:23   ` Steven Rostedt
2019-07-04 19:55 ` [PATCH v2 4/7] x86/entry/64: Update comments and sanity tests for create_gap Peter Zijlstra
2019-07-04 21:55   ` Andy Lutomirski
2019-07-10 20:24   ` Steven Rostedt
2019-07-04 19:56 ` [PATCH v2 5/7] x86/mm, tracing: Fix CR2 corruption Peter Zijlstra
2019-07-05  2:18   ` Linus Torvalds
2019-07-05  3:16     ` Andy Lutomirski
2019-07-05  3:27       ` Linus Torvalds
2019-07-05 13:49     ` Peter Zijlstra
2019-07-06 21:41       ` Linus Torvalds
2019-07-06 22:27         ` Steven Rostedt
2019-07-06 22:41           ` Linus Torvalds
2019-07-07  0:08             ` Linus Torvalds
2019-07-07  0:36               ` Andy Lutomirski
2019-07-06 23:50           ` Andy Lutomirski
2019-07-07  3:44           ` Eiichi Tsukata
2019-07-06 11:07     ` Eiichi Tsukata
2019-07-08  7:48       ` Peter Zijlstra
2019-07-08  8:58         ` Eiichi Tsukata
2019-07-08  9:42           ` Eiichi Tsukata
2019-07-09  5:17             ` Eiichi Tsukata
2019-07-07 15:10   ` Andy Lutomirski
2019-07-07 15:11     ` Andy Lutomirski
2019-07-07 18:17       ` Linus Torvalds
2019-07-10 20:27         ` Steven Rostedt
2019-07-11  6:45           ` Greg Kroah-Hartman
2019-07-11 12:12           ` Sasha Levin
2019-07-11 12:21           ` Peter Zijlstra
2019-07-04 19:56 ` [PATCH v2 6/7] x86/entry/64: Remove TRACE_IRQS_*_DEBUG Peter Zijlstra
2019-07-11  3:24   ` Steven Rostedt
2019-07-11  8:05     ` Peter Zijlstra
2019-07-04 19:56 ` [RFC][PATCH v2 7/7] x86/entry/64: Pull bits into C Peter Zijlstra

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