This is a note to let you know that I've just added the patch titled
locking/lockdep: Improve noinstr vs errors
to the 5.12-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
locking-lockdep-improve-noinstr-vs-errors.patch
and it can be found in the queue-5.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit eb68ed122d6c4ff90d1084734af3684d700e1135
Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Date: Mon Jun 21 13:12:38 2021 +0200
locking/lockdep: Improve noinstr vs errors
[ Upstream commit 49faa77759b211fff344898edc23bb780707fff5 ]
Better handle the failure paths.
vmlinux.o: warning: objtool: debug_locks_off()+0x23: call to console_verbose() leaves .noinstr.text section
vmlinux.o: warning: objtool: debug_locks_off()+0x19: call to __kasan_check_write() leaves .noinstr.text section
debug_locks_off+0x19/0x40:
instrument_atomic_write at include/linux/instrumented.h:86
(inlined by) __debug_locks_off at include/linux/debug_locks.h:17
(inlined by) debug_locks_off at lib/debug_locks.c:41
Fixes: 6eebad1ad303 ("lockdep: __always_inline more for noinstr")
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20210621120120.784404944@xxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/include/linux/debug_locks.h b/include/linux/debug_locks.h
index 2915f56ad421..edb5c186b0b7 100644
--- a/include/linux/debug_locks.h
+++ b/include/linux/debug_locks.h
@@ -27,8 +27,10 @@ extern int debug_locks_off(void);
int __ret = 0; \
\
if (!oops_in_progress && unlikely(c)) { \
+ instrumentation_begin(); \
if (debug_locks_off() && !debug_locks_silent) \
WARN(1, "DEBUG_LOCKS_WARN_ON(%s)", #c); \
+ instrumentation_end(); \
__ret = 1; \
} \
__ret; \
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index f39c383c7180..5bf6b1659215 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -842,7 +842,7 @@ static int count_matching_names(struct lock_class *new_class)
}
/* used from NMI context -- must be lockless */
-static __always_inline struct lock_class *
+static noinstr struct lock_class *
look_up_lock_class(const struct lockdep_map *lock, unsigned int subclass)
{
struct lockdep_subclass_key *key;
@@ -850,12 +850,14 @@ look_up_lock_class(const struct lockdep_map *lock, unsigned int subclass)
struct lock_class *class;
if (unlikely(subclass >= MAX_LOCKDEP_SUBCLASSES)) {
+ instrumentation_begin();
debug_locks_off();
printk(KERN_ERR
"BUG: looking up invalid subclass: %u\n", subclass);
printk(KERN_ERR
"turning off the locking correctness validator.\n");
dump_stack();
+ instrumentation_end();
return NULL;
}
diff --git a/lib/debug_locks.c b/lib/debug_locks.c
index 06d3135bd184..a75ee30b77cb 100644
--- a/lib/debug_locks.c
+++ b/lib/debug_locks.c
@@ -36,7 +36,7 @@ EXPORT_SYMBOL_GPL(debug_locks_silent);
/*
* Generic 'turn off all lock debugging' function:
*/
-noinstr int debug_locks_off(void)
+int debug_locks_off(void)
{
if (debug_locks && __debug_locks_off()) {
if (!debug_locks_silent) {
