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| author | Jinyang He <hejinyang@loongson.cn> | 2024-03-11 15:23:47 +0100 |
|---|---|---|
| committer | Huacai Chen <chenhuacai@loongson.cn> | 2024-03-11 15:23:47 +0100 |
| commit | 199cc14cb4f1cb8668be45f67af41755ed5f0175 (patch) | |
| tree | cf3436e1832645f7e5537e929b2453be3061291b /arch/loongarch/kernel | |
| parent | LoongArch: Add ORC stack unwinder support (diff) | |
| download | linux-199cc14cb4f1cb8668be45f67af41755ed5f0175.tar.xz linux-199cc14cb4f1cb8668be45f67af41755ed5f0175.zip | |
LoongArch: Add kernel livepatching support
The arch-specified function ftrace_regs_set_instruction_pointer() has
been implemented in arch/loongarch/include/asm/ftrace.h, so here only
implement arch_stack_walk_reliable() function.
Here are the test logs:
[root@linux fedora]# cat /proc/cmdline
BOOT_IMAGE=/vmlinuz-6.8.0-rc2 root=/dev/sda3
[root@linux fedora]# modprobe livepatch-sample
[root@linux fedora]# cat /proc/cmdline
this has been live patched
[root@linux fedora]# echo 0 > /sys/kernel/livepatch/livepatch_sample/enabled
[root@linux fedora]# rmmod livepatch_sample
[root@linux fedora]# cat /proc/cmdline
BOOT_IMAGE=/vmlinuz-6.8.0-rc2 root=/dev/sda3
[root@linux fedora]# dmesg -t | tail -5
livepatch: enabling patch 'livepatch_sample'
livepatch: 'livepatch_sample': starting patching transition
livepatch: 'livepatch_sample': patching complete
livepatch: 'livepatch_sample': starting unpatching transition
livepatch: 'livepatch_sample': unpatching complete
Signed-off-by: Jinyang He <hejinyang@loongson.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Diffstat (limited to 'arch/loongarch/kernel')
| -rw-r--r-- | arch/loongarch/kernel/stacktrace.c | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/arch/loongarch/kernel/stacktrace.c b/arch/loongarch/kernel/stacktrace.c index eaec82e02c92..9a038d1070d7 100644 --- a/arch/loongarch/kernel/stacktrace.c +++ b/arch/loongarch/kernel/stacktrace.c @@ -40,6 +40,46 @@ void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie, } } +int arch_stack_walk_reliable(stack_trace_consume_fn consume_entry, + void *cookie, struct task_struct *task) +{ + unsigned long addr; + struct pt_regs dummyregs; + struct pt_regs *regs = &dummyregs; + struct unwind_state state; + + if (task == current) { + regs->regs[3] = (unsigned long)__builtin_frame_address(0); + regs->csr_era = (unsigned long)__builtin_return_address(0); + } else { + regs->regs[3] = thread_saved_fp(task); + regs->csr_era = thread_saved_ra(task); + } + regs->regs[1] = 0; + regs->regs[22] = 0; + + for (unwind_start(&state, task, regs); + !unwind_done(&state) && !unwind_error(&state); unwind_next_frame(&state)) { + addr = unwind_get_return_address(&state); + + /* + * A NULL or invalid return address probably means there's some + * generated code which __kernel_text_address() doesn't know about. + */ + if (!addr) + return -EINVAL; + + if (!consume_entry(cookie, addr)) + return -EINVAL; + } + + /* Check for stack corruption */ + if (unwind_error(&state)) + return -EINVAL; + + return 0; +} + static int copy_stack_frame(unsigned long fp, struct stack_frame *frame) { |