This is a note to let you know that I've just added the patch titled
arm64: kdump: update ppos when reading elfcorehdr
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
arm64-kdump-update-ppos-when-reading-elfcorehdr.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 58126b6df9dc56c36a94614ec3ce1b21676ad810
Author: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
Date: Fri Mar 19 16:50:54 2021 -0400
arm64: kdump: update ppos when reading elfcorehdr
[ 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@xxxxxxxxxx>
Fixes: e62aaeac426a ("arm64: kdump: provide /proc/vmcore file")
Reviewed-by: Tyler Hicks <tyhicks@xxxxxxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210319205054.743368-1-pasha.tatashin@xxxxxxxxxx
Signed-off-by: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/arm64/kernel/crash_dump.c b/arch/arm64/kernel/crash_dump.c
index e6e284265f19..58303a9ec32c 100644
--- a/arch/arm64/kernel/crash_dump.c
+++ b/arch/arm64/kernel/crash_dump.c
@@ -64,5 +64,7 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos)
{
memcpy(buf, phys_to_virt((phys_addr_t)*ppos), count);
+ *ppos += count;
+
return count;
}
