From 0bbbd254473b576a405b9e7b6bae7fbe72277419 Mon Sep 17 00:00:00 2001
From: Dmitry Vyukov <dvyukov@google.com>
Date: Fri, 27 Mar 2020 06:23:11 +0100
Subject: pkg/report: fix detection of questionable frames

The previous commit "pkg/report: handle cases when whole stack is questionable"
mishandles frames that start with [PC] prefix before " ? ".
Restore that part.
---
 pkg/report/linux.go                 |  7 +++++--
 pkg/report/testdata/linux/report/95 | 21 ++++++++++++++++++++-
 2 files changed, 25 insertions(+), 3 deletions(-)

(limited to 'pkg')

diff --git a/pkg/report/linux.go b/pkg/report/linux.go
index 31b6be136..15047377e 100644
--- a/pkg/report/linux.go
+++ b/pkg/report/linux.go
@@ -25,6 +25,7 @@ type linux struct {
 	consoleOutputRe       *regexp.Regexp
 	taskContext           *regexp.Regexp
 	cpuContext            *regexp.Regexp
+	questionableFrame     *regexp.Regexp
 	guiltyFileBlacklist   []*regexp.Regexp
 	reportStartIgnores    []*regexp.Regexp
 	infoMessagesWithStack [][]byte
@@ -50,6 +51,7 @@ func ctorLinux(cfg *config) (Reporter, []string, error) {
 	ctx.consoleOutputRe = regexp.MustCompile(`^(?:\*\* [0-9]+ printk messages dropped \*\* )?(?:.* login: )?(?:\<[0-9]+\>)?\[ *[0-9]+\.[0-9]+\](\[ *(?:C|T)[0-9]+\])? `)
 	ctx.taskContext = regexp.MustCompile(`\[ *T[0-9]+\]`)
 	ctx.cpuContext = regexp.MustCompile(`\[ *C[0-9]+\]`)
+	ctx.questionableFrame = regexp.MustCompile(`(\[\<[0-9a-f]+\>\])? \? `)
 	ctx.eoi = []byte("<EOI>")
 	ctx.guiltyFileBlacklist = []*regexp.Regexp{
 		regexp.MustCompile(`.*\.h`),
@@ -300,8 +302,9 @@ func (ctx *linux) stripLinePrefix(line []byte, context string, useQuestionable b
 	line = line[start+2:]
 	if !bytes.Contains(line, ctx.eoi) {
 		// x86_64 prefix.
-		if bytes.HasPrefix(line, []byte(" ? ")) {
-			return line[2:], !useQuestionable
+		if ctx.questionableFrame.Match(line) {
+			pos := bytes.Index(line, []byte(" ? "))
+			return line[pos+2:], !useQuestionable
 		}
 		// powerpc suffix.
 		if bytes.HasSuffix(line, []byte(" (unreliable)")) {
diff --git a/pkg/report/testdata/linux/report/95 b/pkg/report/testdata/linux/report/95
index 031cd01dc..38736ec6f 100644
--- a/pkg/report/testdata/linux/report/95
+++ b/pkg/report/testdata/linux/report/95
@@ -32,4 +32,23 @@ TITLE: BUG: spinlock already unlocked in synchronize_sched_expedited_cpu_stop
 [  108.804399]  [<ffffffff81338300>] ? kthread_create_on_node+0x460/0x460
 [  108.811031]  [<ffffffff82d2fbac>] ret_from_fork+0x5c/0x90
 [  108.816532]  [<ffffffff81338300>] ? kthread_create_on_node+0x460/0x460
- 
+
+REPORT:
+BUG: spinlock already unlocked on CPU#1, migration/1/12
+ lock: rcu_sched_state+0xb40/0xc20, .magic: dead4ead, .owner: <none>/-1, .owner_cpu: -1
+CPU: 1 PID: 12 Comm: migration/1 Not tainted 4.3.5+ #6
+Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
+ 0000000000000001 ffff8801d8f6fb30 ffffffff81d0010d ffffffff837b69c0
+ ffff8801d8f68340 0000000000000003 0000000000000001 0000000000000000
+ ffff8801d8f6fb70 ffffffff813fba22 0000000000000046 ffff8801d8f68b80
+Call Trace:
+ [<ffffffff81d0010d>] dump_stack+0xc1/0x124
+ [<ffffffff813fba22>] spin_dump+0x152/0x280
+ [<ffffffff813fc152>] do_raw_spin_unlock+0x1e2/0x240
+ [<ffffffff810108ec>] _raw_spin_unlock_irqrestore+0x2c/0x60
+ [<ffffffff813cd204>] __wake_up+0x44/0x50
+ [<ffffffff8142958a>] synchronize_sched_expedited_cpu_stop+0x8a/0xa0
+ [<ffffffff814dbfe8>] cpu_stopper_thread+0x1f8/0x400
+ [<ffffffff8134237c>] smpboot_thread_fn+0x47c/0x880
+ [<ffffffff81338531>] kthread+0x231/0x2c0
+ [<ffffffff82d2fbac>] ret_from_fork+0x5c/0x90
-- 
cgit mrf-deployment