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From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>,
        "H. Peter Anvin" <hpa@zytor.com>, x86@kernel.org,
        linux-kernel@vger.kernel.org, live-patching@vger.kernel.org,
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        Namhyung Kim <namhyung@gmail.com>,
        Bernd Petrovitsch <bernd@petrovitsch.priv.at>,
        Chris J Arges <chris.j.arges@canonical.com>,
        Andrew Morton <akpm@linux-foundation.org>, Jiri Slaby <jslaby@suse.cz>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Pavel Machek <pavel@ucw.cz>
Subject: Re: [PATCH v15 23/25] x86/asm/power: Create stack frames in hibernate_asm_64.S
Date: Sun, 20 Dec 2015 17:14:05 +0100
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On Friday, December 18, 2015 06:39:37 AM Josh Poimboeuf wrote:
> swsusp_arch_suspend() and restore_registers() are callable non-leaf
> functions which 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 a stack frame for them when CONFIG_FRAME_POINTER is enabled and
> give them proper ELF function annotations.
> 
> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
> Acked-by: Pavel Machek <pavel@ucw.cz>
> Cc: Rafael J. Wysocki <rjw@rjwysocki.net>

Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

> ---
>  arch/x86/power/hibernate_asm_64.S | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/arch/x86/power/hibernate_asm_64.S b/arch/x86/power/hibernate_asm_64.S
> index e2386cb..4400a43 100644
> --- a/arch/x86/power/hibernate_asm_64.S
> +++ b/arch/x86/power/hibernate_asm_64.S
> @@ -21,8 +21,10 @@
>  #include <asm/page_types.h>
>  #include <asm/asm-offsets.h>
>  #include <asm/processor-flags.h>
> +#include <asm/frame.h>
>  
>  ENTRY(swsusp_arch_suspend)
> +	FRAME_BEGIN
>  	movq	$saved_context, %rax
>  	movq	%rsp, pt_regs_sp(%rax)
>  	movq	%rbp, pt_regs_bp(%rax)
> @@ -50,7 +52,9 @@ ENTRY(swsusp_arch_suspend)
>  	movq	%rax, restore_cr3(%rip)
>  
>  	call swsusp_save
> +	FRAME_END
>  	ret
> +ENDPROC(swsusp_arch_suspend)
>  
>  ENTRY(restore_image)
>  	/* switch to temporary page tables */
> @@ -107,6 +111,7 @@ ENTRY(core_restore_code)
>  	 */
>  
>  ENTRY(restore_registers)
> +	FRAME_BEGIN
>  	/* go back to the original page tables */
>  	movq    %rbx, %cr3
>  
> @@ -147,4 +152,6 @@ ENTRY(restore_registers)
>  	/* tell the hibernation core that we've just restored the memory */
>  	movq	%rax, in_suspend(%rip)
>  
> +	FRAME_END
>  	ret
> +ENDPROC(restore_registers)
> 

-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.