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authorMasami Hiramatsu <mhiramat@kernel.org>2018-03-12 11:00:49 +0100
committerDaniel Borkmann <daniel@iogearbox.net>2018-03-12 16:16:00 +0100
commitb6b76dd62c56f257cdd30900ed22668c42a74030 (patch)
tree14c8d11284da90abb655fcc9c1da1e5231dde6aa /kernel/fail_function.c
parentMerge branch 'bnxt_en-Bug-fixes' (diff)
downloadlinux-b6b76dd62c56f257cdd30900ed22668c42a74030.tar.xz
linux-b6b76dd62c56f257cdd30900ed22668c42a74030.zip
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.c10
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);
}