diff options
| author | Masami Hiramatsu <mhiramat@kernel.org> | 2021-09-14 23:42:51 +0900 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2021-09-30 21:24:08 -0400 |
| commit | bf094cffea2a6503ce84062f9f0243bef77c58f9 (patch) | |
| tree | c7e59457f4ff4311b54ad508396d9c21170a57cf /include | |
| parent | 7da89495d500d6a1e6fe1019587c3b611c7bd217 (diff) | |
x86/kprobes: Fixup return address in generic trampoline handler
In x86, the fake return address on the stack saved by
__kretprobe_trampoline() will be replaced with the real return
address after returning from trampoline_handler(). Before fixing
the return address, the real return address can be found in the
'current->kretprobe_instances'.
However, since there is a window between updating the
'current->kretprobe_instances' and fixing the address on the stack,
if an interrupt happens at that timing and the interrupt handler
does stacktrace, it may fail to unwind because it can not get
the correct return address from 'current->kretprobe_instances'.
This will eliminate that window by fixing the return address
right before updating 'current->kretprobe_instances'.
Link: https://lkml.kernel.org/r/163163057094.489837.9044470370440745866.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/kprobes.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h index 6d47a9da1e0a..e974caf39d3e 100644 --- a/include/linux/kprobes.h +++ b/include/linux/kprobes.h @@ -188,6 +188,9 @@ extern void arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs); extern int arch_trampoline_kprobe(struct kprobe *p); +void arch_kretprobe_fixup_return(struct pt_regs *regs, + kprobe_opcode_t *correct_ret_addr); + void __kretprobe_trampoline(void); /* * Since some architecture uses structured function pointer, |