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| author | Qing Zhang <zhangqing@loongson.cn> | 2022-08-06 11:10:05 +0300 |
|---|---|---|
| committer | Huacai Chen <chenhuacai@loongson.cn> | 2022-08-12 08:10:11 +0300 |
| commit | 4d7bf939df08218e682f7a42952eee3bad4dceb7 (patch) | |
| tree | dce86915387d231ca6d29f3abd71fc1ef99af295 | |
| parent | 93a4fa622eb061f75f87f0cf9609ab4e69c67d01 (diff) | |
| download | linux-4d7bf939df08218e682f7a42952eee3bad4dceb7.tar.xz | |
LoongArch: Add USER_STACKTRACE support
To get the best stacktrace output, you can compile your userspace
programs with frame pointers (at least glibc + the app you are tracing).
1, export "CC = gcc -fno-omit-frame-pointer";
2, compile your programs with "CC";
3, use uprobe to get stacktrace output.
...
echo 'p:malloc /usr/lib64/libc.so.6:0x0a4704 size=%r4:u64' > uprobe_events
echo 'p:free /usr/lib64/libc.so.6:0x0a4d50 ptr=%r4:x64' >> uprobe_events
echo 'comm == "demo"' > ./events/uprobes/malloc/filter
echo 'comm == "demo"' > ./events/uprobes/free/filter
echo 1 > ./options/userstacktrace
echo 1 > ./options/sym-userobj
...
Signed-off-by: Qing Zhang <zhangqing@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
| -rw-r--r-- | arch/loongarch/Kconfig | 1 | ||||
| -rw-r--r-- | arch/loongarch/include/asm/stacktrace.h | 5 | ||||
| -rw-r--r-- | arch/loongarch/kernel/stacktrace.c | 41 |
3 files changed, 47 insertions, 0 deletions
diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index 947cb633744b..2f110a00a930 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -119,6 +119,7 @@ config LOONGARCH select SWIOTLB select TRACE_IRQFLAGS_SUPPORT select USE_PERCPU_NUMA_NODE_ID + select USER_STACKTRACE_SUPPORT select ZONE_DMA32 config 32BIT diff --git a/arch/loongarch/include/asm/stacktrace.h b/arch/loongarch/include/asm/stacktrace.h index 5820a0cabe3a..f23adb15f418 100644 --- a/arch/loongarch/include/asm/stacktrace.h +++ b/arch/loongarch/include/asm/stacktrace.h @@ -21,6 +21,11 @@ struct stack_info { unsigned long begin, end, next_sp; }; +struct stack_frame { + unsigned long fp; + unsigned long ra; +}; + bool in_irq_stack(unsigned long stack, struct stack_info *info); bool in_task_stack(unsigned long stack, struct task_struct *task, struct stack_info *info); int get_stack_info(unsigned long stack, struct task_struct *task, struct stack_info *info); diff --git a/arch/loongarch/kernel/stacktrace.c b/arch/loongarch/kernel/stacktrace.c index e690c1c769f2..3a690f96f00c 100644 --- a/arch/loongarch/kernel/stacktrace.c +++ b/arch/loongarch/kernel/stacktrace.c @@ -6,6 +6,7 @@ */ #include <linux/sched.h> #include <linux/stacktrace.h> +#include <linux/uaccess.h> #include <asm/stacktrace.h> #include <asm/unwind.h> @@ -35,3 +36,43 @@ void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie, break; } } + +static int +copy_stack_frame(unsigned long fp, struct stack_frame *frame) +{ + int ret = 1; + unsigned long err; + unsigned long __user *user_frame_tail; + + user_frame_tail = (unsigned long *)(fp - sizeof(struct stack_frame)); + if (!access_ok(user_frame_tail, sizeof(*frame))) + return 0; + + pagefault_disable(); + err = (__copy_from_user_inatomic(frame, user_frame_tail, sizeof(*frame))); + if (err || (unsigned long)user_frame_tail >= frame->fp) + ret = 0; + pagefault_enable(); + + return ret; +} + +void arch_stack_walk_user(stack_trace_consume_fn consume_entry, void *cookie, + const struct pt_regs *regs) +{ + unsigned long fp = regs->regs[22]; + + while (fp && !((unsigned long)fp & 0xf)) { + struct stack_frame frame; + + frame.fp = 0; + frame.ra = 0; + if (!copy_stack_frame(fp, &frame)) + break; + if (!frame.ra) + break; + if (!consume_entry(cookie, frame.ra)) + break; + fp = frame.fp; + } +} |