| Message ID | 162601057463.1318837.12052634205343013760.stgit@devnote2 (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | kprobes: Fix stacktrace with kretprobes on x86 | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Not a local patch |
diff --git a/arch/arm/probes/kprobes/core.c b/arch/arm/probes/kprobes/core.c index 67ce7eb8f285..95f23b47ba27 100644 --- a/arch/arm/probes/kprobes/core.c +++ b/arch/arm/probes/kprobes/core.c @@ -376,11 +376,13 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, void __naked __kprobes __kretprobe_trampoline(void) { __asm__ __volatile__ ( + "sub sp, sp, #16 \n\t" "stmdb sp!, {r0 - r11} \n\t" "mov r0, sp \n\t" "bl trampoline_handler \n\t" "mov lr, r0 \n\t" "ldmia sp!, {r0 - r11} \n\t" + "add sp, sp, #16 \n\t" #ifdef CONFIG_THUMB2_KERNEL "bx lr \n\t" #else
Since arm's __kretprobe_trampoline() saves partial 'pt_regs' on the stack, 'regs->ARM_pc' (instruction pointer) is not accessible from the kretprobe handler. This means if instruction_pointer_set() is used from kretprobe handler, it will break the data on the stack. Make space for instruction pointer (ARM_pc) on the stack in the __kretprobe_trampoline() for fixing this problem. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> --- Changes in v9: - Update changelog. --- arch/arm/probes/kprobes/core.c | 2 ++ 1 file changed, 2 insertions(+)