From: Dave Young <dyoung@redhat.com>
To: WANG Chao <chaowang@redhat.com>
Cc: kexec@lists.infradead.org, ebiederm@xmission.com, vgoyal@redhat.com
Subject: Re: [kexec-tools PATCH] x86: extend kernel text size up to 1GB
Date: Fri, 14 Mar 2014 14:12:32 +0800 [thread overview]
Message-ID: <20140314061232.GA8248@dhcp-16-126.nay.redhat.com> (raw)
In-Reply-To: <20140312031309.GA14477@dhcp-17-89.nay.redhat.com>
On 03/12/14 at 11:13am, WANG Chao wrote:
> Currently kexec hard code X86_64_KERNEL_TEXT_SIZE to 512M. With kASLR
> enabled (CONFIG_RANDOMIZED_BASE=y), kernel image base offset could be
> randomized from 0 to 1GB and kexec-tools fails to get kernel virtual
> address from /proc/kcore when the offset is >512M.
>
> Now extend X86_64_KERNEL_TEXT_SIZE to 1GB to adapt kASLR.
>
> Signed-off-by: WANG Chao <chaowang@redhat.com>
> ---
> kexec/arch/i386/crashdump-x86.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kexec/arch/i386/crashdump-x86.h b/kexec/arch/i386/crashdump-x86.h
> index e68b626..a5b2dfd 100644
> --- a/kexec/arch/i386/crashdump-x86.h
> +++ b/kexec/arch/i386/crashdump-x86.h
> @@ -18,7 +18,7 @@ int load_crashdump_segments(struct kexec_info *info, char *mod_cmdline,
> #define X86_64_MAXMEM 0x3fffffffffffUL
>
> /* Kernel text size */
> -#define X86_64_KERNEL_TEXT_SIZE (512UL*1024*1024)
> +#define X86_64_KERNEL_TEXT_SIZE (1UL*1024*1024*1024)
Should define a new macro such as: X86_KERNEL_TEXT_START_LIMIT (1UL*1024*1024*1024)
and then check end addr with X86_64_KERNEL_TEXT_SIZE + X86_64_KERNEL_TEXT_SIZE
Previously I did not find this problem probably because kernel text happen to randomized
to a address < 512M..
BTW since we can get physical start and size from /proc/iomem, why not just get
vaddr by phys_start + PAGE_OFFSET.
>
> #define CRASH_MAX_MEMMAP_NR CRASH_MAX_MEMORY_RANGES
> #define CRASH_MAX_MEMORY_RANGES (MAX_MEMORY_RANGES + 2)
> --
> 1.8.5.3
>
>
> _______________________________________________
> kexec mailing list
> kexec@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/kexec
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next prev parent reply other threads:[~2014-03-14 6:11 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-12 3:13 [kexec-tools PATCH] x86: extend kernel text size up to 1GB WANG Chao
2014-03-14 6:12 ` Dave Young [this message]
2014-03-14 6:47 ` Dave Young
2014-03-14 7:03 ` WANG Chao
2014-03-14 7:08 ` Dave Young
2014-03-14 7:29 ` WANG Chao
2014-03-20 3:44 ` Simon Horman
2014-03-20 4:53 ` WANG Chao
2014-03-20 5:49 ` Simon Horman
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