| Message ID | 163369612899.636038.6691283708565501775.stgit@devnote2 (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | kprobes: Make KUnit and add stacktrace on kretprobe tests | expand |
On Fri, Oct 08, 2021 at 09:28:49PM +0900, Masami Hiramatsu wrote: > Make a frame pointer (make the x29 register points the > address of pt_regs->regs[29]) on __kretprobe_trampoline. > > This frame pointer will be used by the stacktracer when it is > called from the kretprobe handlers. In this case, the stack > tracer will unwind stack to trampoline_probe_handler() and > find the next frame pointer in the stack frame of the > __kretprobe_trampoline(). > > Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> > --- > arch/arm64/kernel/probes/kprobes_trampoline.S | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/arch/arm64/kernel/probes/kprobes_trampoline.S b/arch/arm64/kernel/probes/kprobes_trampoline.S > index 520ee8711db1..9a6499bed58b 100644 > --- a/arch/arm64/kernel/probes/kprobes_trampoline.S > +++ b/arch/arm64/kernel/probes/kprobes_trampoline.S > @@ -66,6 +66,9 @@ SYM_CODE_START(__kretprobe_trampoline) > > save_all_base_regs > > + /* Setup a frame pointer. */ > + add x29, sp, #S_FP > + > mov x0, sp > bl trampoline_probe_handler > /* > @@ -74,6 +77,7 @@ SYM_CODE_START(__kretprobe_trampoline) > */ > mov lr, x0 > > + /* The frame pointer (x29) is restored with other registers. */ > restore_all_base_regs > > add sp, sp, #PT_REGS_SIZE Acked-by: Will Deacon <will@kernel.org> Will
diff --git a/arch/arm64/kernel/probes/kprobes_trampoline.S b/arch/arm64/kernel/probes/kprobes_trampoline.S index 520ee8711db1..9a6499bed58b 100644 --- a/arch/arm64/kernel/probes/kprobes_trampoline.S +++ b/arch/arm64/kernel/probes/kprobes_trampoline.S @@ -66,6 +66,9 @@ SYM_CODE_START(__kretprobe_trampoline) save_all_base_regs + /* Setup a frame pointer. */ + add x29, sp, #S_FP + mov x0, sp bl trampoline_probe_handler /* @@ -74,6 +77,7 @@ SYM_CODE_START(__kretprobe_trampoline) */ mov lr, x0 + /* The frame pointer (x29) is restored with other registers. */ restore_all_base_regs add sp, sp, #PT_REGS_SIZE
Make a frame pointer (make the x29 register points the address of pt_regs->regs[29]) on __kretprobe_trampoline. This frame pointer will be used by the stacktracer when it is called from the kretprobe handlers. In this case, the stack tracer will unwind stack to trampoline_probe_handler() and find the next frame pointer in the stack frame of the __kretprobe_trampoline(). Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> --- arch/arm64/kernel/probes/kprobes_trampoline.S | 4 ++++ 1 file changed, 4 insertions(+)