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| author | Masami Hiramatsu <mhiramat@kernel.org> | 2021-10-21 02:55:35 +0200 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2021-10-22 18:16:53 +0200 |
| commit | fed240d9c9743815fcbc0ca5c0913292ce1f25e2 (patch) | |
| tree | 332b5002123a3db9bd9b6bc9a5f0144f008374eb /arch/arm/kernel/stacktrace.c | |
| parent | ARM: kprobes: Make a frame pointer on __kretprobe_trampoline (diff) | |
| download | linux-fed240d9c9743815fcbc0ca5c0913292ce1f25e2.tar.xz linux-fed240d9c9743815fcbc0ca5c0913292ce1f25e2.zip | |
ARM: Recover kretprobe modified return address in stacktrace
Since the kretprobe replaces the function return address with
the kretprobe_trampoline on the stack, arm unwinder shows it
instead of the correct return address.
This finds the correct return address from the per-task
kretprobe_instances list and verify it is in between the
caller fp and callee fp.
Note that this supports both GCC and clang if CONFIG_FRAME_POINTER=y
and CONFIG_ARM_UNWIND=n. For the ARM unwinder, this is still
not working correctly.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'arch/arm/kernel/stacktrace.c')
| -rw-r--r-- | arch/arm/kernel/stacktrace.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/arch/arm/kernel/stacktrace.c b/arch/arm/kernel/stacktrace.c index db798eac7431..75e905508f27 100644 --- a/arch/arm/kernel/stacktrace.c +++ b/arch/arm/kernel/stacktrace.c @@ -1,5 +1,6 @@ // SPDX-License-Identifier: GPL-2.0-only #include <linux/export.h> +#include <linux/kprobes.h> #include <linux/sched.h> #include <linux/sched/debug.h> #include <linux/stacktrace.h> @@ -65,6 +66,11 @@ int notrace unwind_frame(struct stackframe *frame) frame->sp = *(unsigned long *)(fp - 8); frame->pc = *(unsigned long *)(fp - 4); #endif +#ifdef CONFIG_KRETPROBES + if (is_kretprobe_trampoline(frame->pc)) + frame->pc = kretprobe_find_ret_addr(frame->tsk, + (void *)frame->fp, &frame->kr_cur); +#endif return 0; } @@ -156,6 +162,10 @@ static noinline void __save_stack_trace(struct task_struct *tsk, frame.lr = (unsigned long)__builtin_return_address(0); frame.pc = (unsigned long)__save_stack_trace; } +#ifdef CONFIG_KRETPROBES + frame.kr_cur = NULL; + frame.tsk = tsk; +#endif walk_stackframe(&frame, save_trace, &data); } @@ -173,6 +183,10 @@ void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace) frame.sp = regs->ARM_sp; frame.lr = regs->ARM_lr; frame.pc = regs->ARM_pc; +#ifdef CONFIG_KRETPROBES + frame.kr_cur = NULL; + frame.tsk = current; +#endif walk_stackframe(&frame, save_trace, &data); } |