Hi, Jiaxun
On 04/20/2021 09:11 AM, Jiaxun Yang wrote:
在 2021/4/19 18:56, Youling Tang 写道:
From: Huacai Chen <chenhc@xxxxxxxxxx>
kexec-tools use mem=X@Y to pass usable memories to crash kernel, but in
commit a94e4f24ec836c8984f83959 ("MIPS: init: Drop boot_mem_map") all
BIOS passed memories are removed by early_parse_mem(). I think this is
reasonable for a normal kernel but not for a crash kernel, because a
crash kernel should be able to see all old memories, even though it is
not supposed to use them.
Fixes: a94e4f24ec836c8984f83959 ("MIPS: init: Drop boot_mem_map")
Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxx>
Signed-off-by: Youling Tang <tangyouling@xxxxxxxxxxx>
---
arch/mips/kernel/setup.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index b86e241..ac90d3b 100644
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -351,8 +351,10 @@ static int __init early_parse_mem(char *p)
*/
if (usermem == 0) {
usermem = 1;
+#ifndef CONFIG_CRASH_DUMP
Why depend on a config instead of a runtime variable?
If not depend on config, we can determine whether the command line contains
the "elfcorehdr=" parameter, because the "mem=" and "elfcorhdr=" parameters
are automatically added in kexec-tools. So if there is an "elfcorehdr="
parameter in the command line, it means that the currently running kernel
is a capture kernel, and the memblock_remove() operation is not called.
The revised patch is as follows:
if (usermem == 0) {
usermem = 1;
- memblock_remove(memblock_start_of_DRAM(),
- memblock_end_of_DRAM() - memblock_start_of_DRAM());
+ if (!strstr(boot_command_line, "elfcorehdr")) {
+ memblock_remove(memblock_start_of_DRAM(),
+ memblock_end_of_DRAM() -
memblock_start_of_DRAM());
+ }
Do you think it is feasible?
Btw as you are fixing my commit please keep me CCed.
Sorry, I will add your CCed.
Thanks,
Youling
Thanks.
- Jiaxun
