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arm64: kprobes: Record frame pointer with kretprobe instance

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Record the frame pointer instead of stack address with kretprobe
instance as the identifier on the instance list.
Since arm64 always enable CONFIG_FRAME_POINTER, we can use the
actual frame pointer (x29).

This will allow the stacktrace code to find the original return
address from the FP alone.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This commit is contained in:
Masami Hiramatsu 2021-10-21 09:54:51 +09:00 committed by Steven Rostedt (VMware)
parent 811b93ffaa
commit f871741062
1 changed files with 2 additions and 2 deletions
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4
arch/arm64/kernel/probes/kprobes.c
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@ -401,14 +401,14 @@ int __init arch_populate_kprobe_blacklist(void)
void __kprobes __used *trampoline_probe_handler(struct pt_regs *regs)
{
return (void *)kretprobe_trampoline_handler(regs, (void *)kernel_stack_pointer(regs));
return (void *)kretprobe_trampoline_handler(regs, (void *)regs->regs[29]);
}
void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
struct pt_regs *regs)
{
ri->ret_addr = (kprobe_opcode_t *)regs->regs[30];
ri->fp = (void *)kernel_stack_pointer(regs);
ri->fp = (void *)regs->regs[29];
/* replace return addr (x30) with trampoline */
regs->regs[30] = (long)&__kretprobe_trampoline;