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authorHuacai Chen <chenhuacai@loongson.cn>2024-04-24 12:36:07 +0800
committerHuacai Chen <chenhuacai@loongson.cn>2024-04-24 12:36:07 +0800
commitd3119bc985fb645ad3b2a9cf9952c1d56d9daaa3 (patch)
treed13ea16bf31a57c52466ce7e07491127e90cce2d /arch/loongarch
parentefb44ff64c95340b06331fc48634b99efc9dd77c (diff)
LoongArch: Fix callchain parse error with kernel tracepoint events
In order to fix perf's callchain parse error for LoongArch, we implement perf_arch_fetch_caller_regs() which fills several necessary registers used for callchain unwinding, including sp, fp, and era. This is similar to the following commits. commit b3eac0265bf6: ("arm: perf: Fix callchain parse error with kernel tracepoint events") commit 5b09a094f2fb: ("arm64: perf: Fix callchain parse error with kernel tracepoint events") commit 9a7e8ec0d4cc: ("riscv: perf: Fix callchain parse error with kernel tracepoint events") Test with commands: perf record -e sched:sched_switch -g --call-graph dwarf perf report Without this patch: Children Self Command Shared Object Symbol ........ ........ ............. ................. .................... 43.41% 43.41% swapper [unknown] [k] 0000000000000000 10.94% 10.94% loong-container [unknown] [k] 0000000000000000 | |--5.98%--0x12006ba38 | |--2.56%--0x12006bb84 | --2.40%--0x12006b6b8 With this patch, callchain can be parsed correctly: Children Self Command Shared Object Symbol ........ ........ ............. ................. .................... 47.57% 47.57% swapper [kernel.vmlinux] [k] __schedule | ---__schedule 26.76% 26.76% loong-container [kernel.vmlinux] [k] __schedule | |--13.78%--0x12006ba38 | | | |--9.19%--__schedule | | | --4.59%--handle_syscall | do_syscall | sys_futex | do_futex | futex_wait | futex_wait_queue_me | hrtimer_start_range_ns | __schedule | |--8.38%--0x12006bb84 | handle_syscall | do_syscall | sys_epoll_pwait | do_epoll_wait | schedule_hrtimeout_range_clock | hrtimer_start_range_ns | __schedule | --4.59%--0x12006b6b8 handle_syscall do_syscall sys_nanosleep hrtimer_nanosleep do_nanosleep hrtimer_start_range_ns __schedule Cc: stable@vger.kernel.org Fixes: b37042b2bb7cd751f0 ("LoongArch: Add perf events support") Reported-by: Youling Tang <tangyouling@kylinos.cn> Suggested-by: Youling Tang <tangyouling@kylinos.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Diffstat (limited to 'arch/loongarch')
-rw-r--r--arch/loongarch/include/asm/perf_event.h8
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/loongarch/include/asm/perf_event.h b/arch/loongarch/include/asm/perf_event.h
index 2a35a0bc2aaa..52b638059e40 100644
--- a/arch/loongarch/include/asm/perf_event.h
+++ b/arch/loongarch/include/asm/perf_event.h
@@ -7,6 +7,14 @@
#ifndef __LOONGARCH_PERF_EVENT_H__
#define __LOONGARCH_PERF_EVENT_H__
+#include <asm/ptrace.h>
+
#define perf_arch_bpf_user_pt_regs(regs) (struct user_pt_regs *)regs
+#define perf_arch_fetch_caller_regs(regs, __ip) { \
+ (regs)->csr_era = (__ip); \
+ (regs)->regs[3] = current_stack_pointer; \
+ (regs)->regs[22] = (unsigned long) __builtin_frame_address(0); \
+}
+
#endif /* __LOONGARCH_PERF_EVENT_H__ */