diff options
| author | Masami Hiramatsu <mhiramat@kernel.org> | 2018-03-12 19:00:49 +0900 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2018-03-12 16:16:00 +0100 |
| commit | b6b76dd62c56f257cdd30900ed22668c42a74030 (patch) | |
| tree | 14c8d11284da90abb655fcc9c1da1e5231dde6aa /kernel/fail_function.c | |
| parent | 9e5fb7207024e53700bdac23f53d1e44d530a7f6 (diff) | |
error-injection: Fix to prohibit jump optimization
Since the kprobe which was optimized by jump can not change
the execution path, the kprobe for error-injection must not
be optimized. To prohibit it, set a dummy post-handler as
officially stated in Documentation/kprobes.txt.
Fixes: 4b1a29a7f542 ("error-injection: Support fault injection framework")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'kernel/fail_function.c')
| -rw-r--r-- | kernel/fail_function.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/kernel/fail_function.c b/kernel/fail_function.c index 21b0122cb39c..1d5632d8bbcc 100644 --- a/kernel/fail_function.c +++ b/kernel/fail_function.c @@ -14,6 +14,15 @@ static int fei_kprobe_handler(struct kprobe *kp, struct pt_regs *regs); +static void fei_post_handler(struct kprobe *kp, struct pt_regs *regs, + unsigned long flags) +{ + /* + * A dummy post handler is required to prohibit optimizing, because + * jump optimization does not support execution path overriding. + */ +} + struct fei_attr { struct list_head list; struct kprobe kp; @@ -56,6 +65,7 @@ static struct fei_attr *fei_attr_new(const char *sym, unsigned long addr) return NULL; } attr->kp.pre_handler = fei_kprobe_handler; + attr->kp.post_handler = fei_post_handler; attr->retval = adjust_error_retval(addr, 0); INIT_LIST_HEAD(&attr->list); } |