From f9eeef5918bbe1f2545d36280330dced25d6cf97 Mon Sep 17 00:00:00 2001
From: Wei Yongjun <weiyongjun1@huawei.com>
Date: Wed, 17 Aug 2022 08:03:32 +0000
Subject: [PATCH] fault-injection: make stacktrace filter works as expected
stacktrace filter is checked after others, such as fail-nth, interval and
probability. This make it doesn't work well as expected.
Fix to running stacktrace filter before other filters. It will speed up
fault inject testing for driver modules.
Link: https://lkml.kernel.org/r/20220817080332.1052710-5-weiyongjun1@huawei.com
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Isabella Basso <isabbasso@riseup.net>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
lib/fault-inject.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/lib/fault-inject.c b/lib/fault-inject.c
index d7819cacf8901..6cff320c4eb40 100644
--- a/lib/fault-inject.c
+++ b/lib/fault-inject.c
@@ -102,10 +102,16 @@ static inline bool fail_stacktrace(struct fault_attr *attr)
bool should_fail_ex(struct fault_attr *attr, ssize_t size, int flags)
{
+ bool stack_checked = false;
+
if (in_task()) {
unsigned int fail_nth = READ_ONCE(current->fail_nth);
if (fail_nth) {
+ if (!fail_stacktrace(attr))
+ return false;
+
+ stack_checked = true;
fail_nth--;
WRITE_ONCE(current->fail_nth, fail_nth);
if (!fail_nth)
@@ -125,6 +131,9 @@ bool should_fail_ex(struct fault_attr *attr, ssize_t size, int flags)
if (atomic_read(&attr->times) == 0)
return false;
+ if (!stack_checked && !fail_stacktrace(attr))
+ return false;
+
if (atomic_read(&attr->space) > size) {
atomic_sub(size, &attr->space);
return false;
@@ -139,9 +148,6 @@ bool should_fail_ex(struct fault_attr *attr, ssize_t size, int flags)
if (attr->probability <= get_random_u32_below(100))
return false;
- if (!fail_stacktrace(attr))
- return false;
-
fail:
if (!(flags & FAULT_NOWARN))
fail_dump(attr);
--
2.30.2