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| author | Youling Tang <tangyouling@loongson.cn> | 2022-10-12 11:36:19 +0300 |
|---|---|---|
| committer | Huacai Chen <chenhuacai@loongson.cn> | 2022-10-12 11:36:19 +0300 |
| commit | 4e62d1d86585e1b62b4f96ee586881dd45a443dc (patch) | |
| tree | 9f2d3d290bcbca2ee14787441f1ae6d174ec1875 /arch/loongarch/kernel/traps.c | |
| parent | 4a03b2ac06a5bcae29371866d9d11f5bfd4c9188 (diff) | |
| download | linux-4e62d1d86585e1b62b4f96ee586881dd45a443dc.tar.xz | |
LoongArch: Add kdump support
This patch adds support for kdump. In kdump case the normal kernel will
reserve a region for the crash kernel and jump there on panic.
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, such as kexec-tools, is responsible for allocating a
separate region for the core's ELF header within the crash kdump kernel
memory and filling it in when executing kexec_load().
Then, its location will be advertised to the crash dump kernel via a
command line argument "elfcorehdr=", and the crash dump kernel will
preserve this region for later use with arch_reserve_vmcore() at boot
time.
At the same time, the crash kdump kernel is also limited within the
"crashkernel" area via a command line argument "mem=", so as not to
destroy the original kernel dump data.
In the crash dump kernel environment, /proc/vmcore is used to access the
primary kernel's memory with copy_oldmem_page().
I tested kdump on LoongArch machines (Loongson-3A5000) and it works as
expected (suggested crashkernel parameter is "crashkernel=512M@2560M"),
you may test it by triggering a crash through /proc/sysrq-trigger:
$ sudo kexec -p /boot/vmlinux-kdump --reuse-cmdline --append="nr_cpus=1"
# echo c > /proc/sysrq-trigger
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Diffstat (limited to 'arch/loongarch/kernel/traps.c')
| -rw-r--r-- | arch/loongarch/kernel/traps.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/loongarch/kernel/traps.c b/arch/loongarch/kernel/traps.c index 66c2849b26e5..1a4dce84ebc6 100644 --- a/arch/loongarch/kernel/traps.c +++ b/arch/loongarch/kernel/traps.c @@ -10,6 +10,7 @@ #include <linux/entry-common.h> #include <linux/init.h> #include <linux/kernel.h> +#include <linux/kexec.h> #include <linux/module.h> #include <linux/extable.h> #include <linux/mm.h> @@ -246,6 +247,9 @@ void __noreturn die(const char *str, struct pt_regs *regs) oops_exit(); + if (regs && kexec_should_crash(current)) + crash_kexec(regs); + if (in_interrupt()) panic("Fatal exception in interrupt"); |