kernel.git/arch/arm64/kernel/crash_dump.c, branch linux-4.14.yHosts the 0x221E linux distro kernel.
https://git.0xinfinity.dev/distro/kernel.git/atom?h=linux-4.14.y2021-03-30T12:40:11Zarm64: kdump: update ppos when reading elfcorehdr2021-03-30T12:40:11ZPavel Tatashin2021-03-19T20:50:54Zurn:sha1:235d33fe3dfae78767cca5f0910a2cb1f8ff281e
[ Upstream commit 141f8202cfa4192c3af79b6cbd68e7760bb01b5a ]
The ppos points to a position in the old kernel memory (and in case of
arm64 in the crash kernel since elfcorehdr is passed as a segment). The
function should update the ppos by the amount that was read. This bug is
not exposed by accident, but other platforms update this value properly.
So, fix it in ARM64 version of elfcorehdr_read() as well.
Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Fixes: e62aaeac426a ("arm64: kdump: provide /proc/vmcore file")
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Link: https://lore.kernel.org/r/20210319205054.743368-1-pasha.tatashin@soleen.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
arm64: kdump: provide /proc/vmcore file2017-04-05T17:31:38ZAKASHI Takahiro2017-04-03T02:24:38Zurn:sha1:e62aaeac426ab1ddbdde524797b2a7835f606d91
Arch-specific functions are added to allow for implementing a crash dump
file interface, /proc/vmcore, which can be viewed as a ELF file.
A user space tool, like kexec-tools, is responsible for allocating
a separate region for the core's ELF header within crash kdump kernel
memory and filling it in when executing kexec_load().
Then, its location will be advertised to crash dump kernel via a new
device-tree property, "linux,elfcorehdr", and crash dump kernel preserves
the region for later use with reserve_elfcorehdr() at boot time.
On crash dump kernel, /proc/vmcore will access the primary kernel's memory
with copy_oldmem_page(), which feeds the data page-by-page by ioremap'ing
it since it does not reside in linear mapping on crash dump kernel.
Meanwhile, elfcorehdr_read() is simple as the region is always mapped.
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Reviewed-by: James Morse <james.morse@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>