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From: Dave Young <dyoung@redhat.com>
To: Laura Abbott <labbott@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>,
	Ard Biesheuvel <ard.biesheuvel@linaro.org>,
	Will Deacon <will.deacon@arm.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Eric Biederman <ebiederm@xmission.com>,
	x86@kernel.org, kexec@lists.infradead.org,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
	Joonsoo Kim <iamjoonsoo.kim@lge.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Andrew Morton <akpm@linux-foundation.org>,
	linux-arm-kernel@lists.infradead.org,
	Marek Szyprowski <m.szyprowski@samsung.com>
Subject: Re: [PATCHv4 07/10] kexec: Switch to __pa_symbol
Date: Thu, 1 Dec 2016 10:41:03 +0800	[thread overview]
Message-ID: <20161201024103.GA32438@dhcp-128-65.nay.redhat.com> (raw)
In-Reply-To: <1480445729-27130-8-git-send-email-labbott@redhat.com>

Hi, Laura
On 11/29/16 at 10:55am, Laura Abbott wrote:
> 
> __pa_symbol is the correct api to get the physical address of kernel
> symbols. Switch to it to allow for better debug checking.
> 

I assume __pa_symbol is faster than __pa, but it still need some testing
on all arches which support kexec.

But seems long long ago there is a commit e3ebadd95cb in the commit log
I see below from:
"we should deprecate __pa_symbol(), and preferably __pa() too - and
 just use "virt_to_phys()" instead, which is is more readable and has
 nicer semantics."

But maybe in modern code __pa_symbol is prefered I may miss background.
virt_to_phys still sounds more readable now for me though.

> Signed-off-by: Laura Abbott <labbott@redhat.com>
> ---
> Found during review of the kernel. Untested.
> ---
>  kernel/kexec_core.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
> index 5616755..e1b625e 100644
> --- a/kernel/kexec_core.c
> +++ b/kernel/kexec_core.c
> @@ -1397,7 +1397,7 @@ void __weak arch_crash_save_vmcoreinfo(void)
>  
>  phys_addr_t __weak paddr_vmcoreinfo_note(void)
>  {
> -	return __pa((unsigned long)(char *)&vmcoreinfo_note);
> +	return __pa_symbol((unsigned long)(char *)&vmcoreinfo_note);
>  }
>  
>  static int __init crash_save_vmcoreinfo_init(void)
> -- 
> 2.7.4
> 
> 
> _______________________________________________
> kexec mailing list
> kexec@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/kexec

Thanks
Dave

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  reply	other threads:[~2016-12-01  2:41 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-11-29 18:55 [PATCHv4 00/10] CONFIG_DEBUG_VIRTUAL for arm64 Laura Abbott
2016-11-29 18:55 ` [PATCHv4 01/10] lib/Kconfig.debug: Add ARCH_HAS_DEBUG_VIRTUAL Laura Abbott
2016-11-29 18:55 ` [PATCHv4 02/10] mm/cma: Cleanup highmem check Laura Abbott
2016-11-29 18:55 ` [PATCHv4 03/10] arm64: Move some macros under #ifndef __ASSEMBLY__ Laura Abbott
2016-11-29 18:55 ` [PATCHv4 04/10] arm64: Add cast for virt_to_pfn Laura Abbott
2016-11-29 18:55 ` [PATCHv4 05/10] arm64: Use __pa_symbol for kernel symbols Laura Abbott
2016-11-30 17:17   ` Catalin Marinas
2016-12-01 12:04   ` James Morse
2016-12-06 16:08     ` Mark Rutland
2016-12-06  0:50   ` Florian Fainelli
2016-12-06 11:46     ` Catalin Marinas
2016-12-06 17:02   ` Mark Rutland
2016-12-06 19:12     ` Laura Abbott
2016-11-29 18:55 ` [PATCHv4 06/10] xen: Switch to using __pa_symbol Laura Abbott
2016-11-29 22:26   ` Boris Ostrovsky
2016-11-29 22:42     ` Laura Abbott
2016-11-29 18:55 ` [PATCHv4 07/10] kexec: Switch to __pa_symbol Laura Abbott
2016-12-01  2:41   ` Dave Young [this message]
2016-12-01  3:13     ` Eric W. Biederman
2016-12-01  4:27       ` Dave Young
2016-11-29 18:55 ` [PATCHv4 08/10] mm/kasan: Switch to using __pa_symbol and lm_alias Laura Abbott
2016-12-01 11:36   ` Andrey Ryabinin
2016-12-01 19:10     ` Laura Abbott
2016-12-06 17:25     ` Mark Rutland
2016-12-06 17:44   ` Mark Rutland
2016-12-06 19:18   ` Mark Rutland
2016-11-29 18:55 ` [PATCHv4 09/10] mm/usercopy: Switch to using lm_alias Laura Abbott
2016-11-29 19:39   ` Kees Cook
2016-12-06 18:18     ` Mark Rutland
2016-12-06 20:10       ` Kees Cook
2016-12-07 13:57         ` Mark Rutland
2016-12-06 18:20   ` Mark Rutland
2016-11-29 18:55 ` [PATCHv4 10/10] arm64: Add support for CONFIG_DEBUG_VIRTUAL Laura Abbott
2016-12-06 18:58   ` Mark Rutland

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