From: James Morse <james.morse@arm.com>
To: Geoff Levand <geoff@infradead.org>,
AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>,
marc.zyngier@arm.com, Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>,
linux-arm-kernel@lists.infradead.org, kexec@lists.infradead.org,
christoffer.dall@linaro.org
Subject: Re: [PATCH 16/19] arm64: kdump: add kdump support
Date: Thu, 21 Jan 2016 14:17:13 +0000 [thread overview]
Message-ID: <56A0E869.1020906@arm.com> (raw)
In-Reply-To: <c1faadcc74ca0670413396b36e2bdcc02b15bcd9.1452884156.git.geoff@infradead.org>
Hi!
On 15/01/16 19:18, Geoff Levand wrote:
> From: AKASHI Takahiro <takahiro.akashi@linaro.org>
>
> On crash dump kernel, all the information about primary kernel's core
> image is available in elf core header specified by "elfcorehdr=" boot
> parameter. reserve_elfcorehdr() will set aside the region to avoid any
> corruption by crash dump kernel.
>
> Crash dump kernel will access the system memory of primary kernel via
> copy_oldmem_page(), which reads one page by ioremap'ing it since it does
> not reside in linear mapping on crash dump kernel.
> Please note that we should add "mem=X[MG]" boot parameter to limit the
> memory size and avoid the following assertion at ioremap():
> if (WARN_ON(pfn_valid(__phys_to_pfn(phys_addr))))
> return NULL;
> when accessing any pages beyond the usable memories of crash dump kernel.
>
> We also need our own elfcorehdr_read() here since the weak definition of
> elfcorehdr_read() utilizes copy_oldmem_page() and will hit the assertion
> above on arm64.
How does this work for a different-endian crash kernel?
It looks like fs/proc/vmcore.c:parse_crash_elf64_headers() does some
validation on the elf-headers that doesn't look like it will work if
elfcorehdr:endian != kernel:endian.
Is it worth preventing this corner case by getting kexec-tools to
prevent linux with a different endianness being loaded as a kdump kernel?
Thanks,
James
_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec
WARNING: multiple messages have this Message-ID (diff)
From: james.morse@arm.com (James Morse)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 16/19] arm64: kdump: add kdump support
Date: Thu, 21 Jan 2016 14:17:13 +0000 [thread overview]
Message-ID: <56A0E869.1020906@arm.com> (raw)
In-Reply-To: <c1faadcc74ca0670413396b36e2bdcc02b15bcd9.1452884156.git.geoff@infradead.org>
Hi!
On 15/01/16 19:18, Geoff Levand wrote:
> From: AKASHI Takahiro <takahiro.akashi@linaro.org>
>
> On crash dump kernel, all the information about primary kernel's core
> image is available in elf core header specified by "elfcorehdr=" boot
> parameter. reserve_elfcorehdr() will set aside the region to avoid any
> corruption by crash dump kernel.
>
> Crash dump kernel will access the system memory of primary kernel via
> copy_oldmem_page(), which reads one page by ioremap'ing it since it does
> not reside in linear mapping on crash dump kernel.
> Please note that we should add "mem=X[MG]" boot parameter to limit the
> memory size and avoid the following assertion at ioremap():
> if (WARN_ON(pfn_valid(__phys_to_pfn(phys_addr))))
> return NULL;
> when accessing any pages beyond the usable memories of crash dump kernel.
>
> We also need our own elfcorehdr_read() here since the weak definition of
> elfcorehdr_read() utilizes copy_oldmem_page() and will hit the assertion
> above on arm64.
How does this work for a different-endian crash kernel?
It looks like fs/proc/vmcore.c:parse_crash_elf64_headers() does some
validation on the elf-headers that doesn't look like it will work if
elfcorehdr:endian != kernel:endian.
Is it worth preventing this corner case by getting kexec-tools to
prevent linux with a different endianness being loaded as a kdump kernel?
Thanks,
James
next prev parent reply other threads:[~2016-01-21 14:17 UTC|newest]
Thread overview: 174+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-15 19:18 [PATCH 00/19] arm64 kexec kernel patches v13 Geoff Levand
2016-01-15 19:18 ` Geoff Levand
2016-01-15 19:18 ` [PATCH 06/19] arm64: Add new hcall HVC_CALL_FUNC Geoff Levand
2016-01-15 19:18 ` Geoff Levand
2016-01-15 19:18 ` [PATCH 04/19] arm64: Cleanup SCTLR flags Geoff Levand
2016-01-15 19:18 ` Geoff Levand
2016-01-15 20:07 ` Mark Rutland
2016-01-15 20:07 ` Mark Rutland
2016-01-18 10:12 ` Marc Zyngier
2016-01-18 10:12 ` Marc Zyngier
2016-01-19 11:59 ` Dave Martin
2016-01-19 11:59 ` Dave Martin
2016-01-25 15:09 ` James Morse
2016-01-25 15:09 ` James Morse
2016-01-15 19:18 ` [PATCH 07/19] arm64: Add back cpu_reset routines Geoff Levand
2016-01-15 19:18 ` Geoff Levand
2016-01-15 19:18 ` [PATCH 05/19] arm64: Convert hcalls to use HVC immediate value Geoff Levand
2016-01-15 19:18 ` Geoff Levand
2016-01-15 19:18 ` [PATCH 01/19] arm64: Fold proc-macros.S into assembler.h Geoff Levand
2016-01-15 19:18 ` Geoff Levand
2016-01-15 19:18 ` [PATCH 03/19] arm64: Add new asm macro copy_page Geoff Levand
2016-01-15 19:18 ` Geoff Levand
2016-01-20 14:01 ` James Morse
2016-01-20 14:01 ` James Morse
2016-01-15 19:18 ` [PATCH 09/19] Revert "arm64: remove dead code" Geoff Levand
2016-01-15 19:18 ` Geoff Levand
2016-01-15 19:55 ` Mark Rutland
2016-01-15 19:55 ` Mark Rutland
2016-01-20 21:18 ` Geoff Levand
2016-01-20 21:18 ` Geoff Levand
2016-01-15 19:18 ` [PATCH 08/19] Revert "arm64: mm: remove unused cpu_set_idmap_tcr_t0sz function" Geoff Levand
2016-01-15 19:18 ` Geoff Levand
2016-01-15 19:18 ` [PATCH 02/19] arm64: kernel: Include _AC definition in page.h Geoff Levand
2016-01-15 19:18 ` Geoff Levand
2016-01-18 10:05 ` Mark Rutland
2016-01-18 10:05 ` Mark Rutland
2016-01-15 19:18 ` [PATCH 10/19] arm64: kvm: allows kvm cpu hotplug Geoff Levand
2016-01-15 19:18 ` Geoff Levand
2016-01-26 17:42 ` James Morse
2016-01-26 17:42 ` James Morse
2016-01-27 7:37 ` AKASHI Takahiro
2016-01-27 7:37 ` AKASHI Takahiro
2016-01-15 19:18 ` [PATCH 16/19] arm64: kdump: add kdump support Geoff Levand
2016-01-15 19:18 ` Geoff Levand
2016-01-21 14:17 ` James Morse [this message]
2016-01-21 14:17 ` James Morse
2016-01-22 4:50 ` AKASHI Takahiro
2016-01-22 4:50 ` AKASHI Takahiro
2016-01-15 19:18 ` [PATCH 17/19] arm64: kdump: enable kdump in the arm64 defconfig Geoff Levand
2016-01-15 19:18 ` Geoff Levand
2016-01-15 19:18 ` [PATCH 18/19] arm64: kdump: update a kernel doc Geoff Levand
2016-01-15 19:18 ` Geoff Levand
2016-01-15 20:16 ` Mark Rutland
2016-01-15 20:16 ` Mark Rutland
2016-01-18 10:26 ` AKASHI Takahiro
2016-01-18 10:26 ` AKASHI Takahiro
2016-01-18 11:29 ` Mark Rutland
2016-01-18 11:29 ` Mark Rutland
2016-01-19 5:31 ` AKASHI Takahiro
2016-01-19 5:31 ` AKASHI Takahiro
2016-01-19 12:10 ` Mark Rutland
2016-01-19 12:10 ` Mark Rutland
2016-01-20 4:34 ` AKASHI Takahiro
2016-01-20 4:34 ` AKASHI Takahiro
2016-01-19 1:43 ` Dave Young
2016-01-19 1:43 ` Dave Young
2016-01-19 1:50 ` Dave Young
2016-01-19 1:50 ` Dave Young
2016-01-19 5:35 ` AKASHI Takahiro
2016-01-19 5:35 ` AKASHI Takahiro
2016-01-19 12:28 ` Dave Young
2016-01-19 12:28 ` Dave Young
2016-01-19 12:51 ` Mark Rutland
2016-01-19 12:51 ` Mark Rutland
2016-01-19 13:45 ` Dave Young
2016-01-19 13:45 ` Dave Young
2016-01-19 14:01 ` Mark Rutland
2016-01-19 14:01 ` Mark Rutland
2016-01-20 2:49 ` Dave Young
2016-01-20 2:49 ` Dave Young
2016-01-20 6:07 ` AKASHI Takahiro
2016-01-20 6:07 ` AKASHI Takahiro
2016-01-20 6:38 ` Dave Young
2016-01-20 6:38 ` Dave Young
2016-01-20 7:00 ` Dave Young
2016-01-20 7:00 ` Dave Young
2016-01-20 8:01 ` AKASHI Takahiro
2016-01-20 8:01 ` AKASHI Takahiro
2016-01-20 8:26 ` Dave Young
2016-01-20 8:26 ` Dave Young
2016-01-20 11:54 ` Mark Rutland
2016-01-20 11:54 ` Mark Rutland
2016-01-21 2:57 ` Dave Young
2016-01-21 2:57 ` Dave Young
2016-01-21 3:03 ` Dave Young
2016-01-21 3:03 ` Dave Young
2016-01-20 11:49 ` Mark Rutland
2016-01-20 11:49 ` Mark Rutland
2016-01-21 6:53 ` AKASHI Takahiro
2016-01-21 6:53 ` AKASHI Takahiro
2016-01-21 12:02 ` Mark Rutland
2016-01-21 12:02 ` Mark Rutland
2016-01-22 6:23 ` AKASHI Takahiro
2016-01-22 6:23 ` AKASHI Takahiro
2016-01-22 11:13 ` Mark Rutland
2016-01-22 11:13 ` Mark Rutland
2016-02-02 5:18 ` AKASHI Takahiro
2016-02-02 5:18 ` AKASHI Takahiro
2016-01-25 3:19 ` Dave Young
2016-01-25 3:19 ` Dave Young
2016-01-25 4:23 ` Dave Young
2016-01-25 4:23 ` Dave Young
2016-01-20 11:28 ` Mark Rutland
2016-01-20 11:28 ` Mark Rutland
2016-01-21 2:54 ` Dave Young
2016-01-21 2:54 ` Dave Young
2016-01-20 5:25 ` AKASHI Takahiro
2016-01-20 5:25 ` AKASHI Takahiro
2016-01-20 12:02 ` Mark Rutland
2016-01-20 12:02 ` Mark Rutland
2016-01-20 12:36 ` Mark Rutland
2016-01-20 12:36 ` Mark Rutland
2016-01-20 14:59 ` Ard Biesheuvel
2016-01-20 14:59 ` Ard Biesheuvel
2016-01-20 15:04 ` Mark Rutland
2016-01-20 15:04 ` Mark Rutland
2016-01-21 5:43 ` AKASHI Takahiro
2016-01-21 5:43 ` AKASHI Takahiro
2016-01-21 13:02 ` Mark Rutland
2016-01-21 13:02 ` Mark Rutland
2016-01-19 12:17 ` Mark Rutland
2016-01-19 12:17 ` Mark Rutland
2016-01-19 13:52 ` Dave Young
2016-01-19 13:52 ` Dave Young
2016-01-19 14:05 ` Mark Rutland
2016-01-19 14:05 ` Mark Rutland
2016-01-20 2:54 ` Dave Young
2016-01-20 2:54 ` Dave Young
2016-01-15 19:18 ` [PATCH 14/19] arm64: kdump: reserve memory for crash dump kernel Geoff Levand
2016-01-15 19:18 ` Geoff Levand
2016-01-15 19:18 ` [PATCH 15/19] arm64: kdump: implement machine_crash_shutdown() Geoff Levand
2016-01-15 19:18 ` Geoff Levand
2016-01-15 19:18 ` [PATCH 13/19] arm64/kexec: Add pr_debug output Geoff Levand
2016-01-15 19:18 ` Geoff Levand
2016-01-15 19:18 ` [PATCH 11/19] arm64/kexec: Add core kexec support Geoff Levand
2016-01-15 19:18 ` Geoff Levand
2016-01-15 19:18 ` [PATCH 12/19] arm64/kexec: Enable kexec in the arm64 defconfig Geoff Levand
2016-01-15 19:18 ` Geoff Levand
2016-01-15 19:18 ` [PATCH 19/19] arm64: kdump: relax BUG_ON() if more than one cpus are still active Geoff Levand
2016-01-15 19:18 ` Geoff Levand
2016-01-19 12:32 ` [PATCH 00/19] arm64 kexec kernel patches v13 Dave Young
2016-01-19 12:32 ` Dave Young
2016-01-20 0:15 ` Geoff Levand
2016-01-20 0:15 ` Geoff Levand
2016-01-20 2:56 ` Dave Young
2016-01-20 2:56 ` Dave Young
2016-01-20 21:15 ` Geoff Levand
2016-01-20 21:15 ` Geoff Levand
2016-01-21 12:11 ` Mark Rutland
2016-01-21 12:11 ` Mark Rutland
[not found] ` <c7575f853ccc491bb0212e025aab1cc9@NASANEXM01H.na.qualcomm.com>
2016-03-01 17:54 ` Azriel Samson
2016-03-01 17:54 ` Azriel Samson
2016-03-02 1:17 ` Geoff Levand
2016-03-02 1:17 ` Geoff Levand
2016-03-02 1:38 ` Will Deacon
2016-03-02 1:38 ` Will Deacon
2016-03-02 2:28 ` AKASHI Takahiro
2016-03-02 2:28 ` AKASHI Takahiro
2016-03-02 8:07 ` Marc Zyngier
2016-03-02 8:07 ` Marc Zyngier
2016-03-02 12:33 ` Pratyush Anand
2016-03-02 12:33 ` Pratyush Anand
2016-03-02 16:51 ` Azriel Samson
2016-03-02 16:51 ` Azriel Samson
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