The patch titled
Subject: crash: fix crash memory reserve exceed system memory bug
has been added to the -mm mm-nonmm-unstable branch. Its filename is
crash-fix-crash-memory-reserve-exceed-system-memory-bug.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/crash-fix-crash-memory-reserve-exceed-system-memory-bug.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Jinjie Ruan <ruanjinjie@xxxxxxxxxx>
Subject: crash: fix crash memory reserve exceed system memory bug
Date: Mon, 29 Jul 2024 19:52:52 +0800
On x86_32 Qemu machine with 1GB memory, the cmdline "crashkernel=4G" is ok
as below:
crashkernel reserved: 0x0000000020000000 - 0x0000000120000000 (4096 MB)
It's similar on other architectures, such as ARM32 and RISCV32.
The cause is that the crash_size is parsed and printed with "unsigned long
long" data type which is 8 bytes but allocated used with "phys_addr_t"
which is 4 bytes in memblock_phys_alloc_range().
Fix it by checking if crash_size is greater than system RAM size and
return error if so.
After this patch, there is no above confusing reserve success info.
Link: https://lkml.kernel.org/r/20240729115252.1659112-1-ruanjinjie@xxxxxxxxxx
Signed-off-by: Jinjie Ruan <ruanjinjie@xxxxxxxxxx>
Suggested-by: Mike Rapoport <rppt@xxxxxxxxxx>
Acked-by: Baoquan He <bhe@xxxxxxxxxx>
Cc: Albert Ou <aou@xxxxxxxxxxxxxxxxx>
Cc: Dave Young <dyoung@xxxxxxxxxx>
Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx>
Cc: Paul Walmsley <paul.walmsley@xxxxxxxxxx>
Cc: Vivek Goyal <vgoyal@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/crash_reserve.c | 3 +++
1 file changed, 3 insertions(+)
--- a/kernel/crash_reserve.c~crash-fix-crash-memory-reserve-exceed-system-memory-bug
+++ a/kernel/crash_reserve.c
@@ -335,6 +335,9 @@ int __init parse_crashkernel(char *cmdli
if (!*crash_size)
ret = -EINVAL;
+ if (*crash_size >= system_ram)
+ ret = -EINVAL;
+
return ret;
}
_
Patches currently in -mm which might be from ruanjinjie@xxxxxxxxxx are
crash-fix-x86_32-crash-memory-reserve-dead-loop-bug.patch
crash-fix-x86_32-crash-memory-reserve-dead-loop.patch
arm-use-generic-interface-to-simplify-crashkernel-reservation.patch
crash-fix-crash-memory-reserve-exceed-system-memory-bug.patch
