locking/lockdep: Improve noinstr vs errors
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@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210621120120.784404944@infradead.org
diff --git a/include/linux/debug_locks.h b/include/linux/debug_locks.h
index 2915f56..edb5c18 100644
--- a/include/linux/debug_locks.h
+++ b/include/linux/debug_locks.h
@@ -27,8 +27,10 @@
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 7641bd4..e323130 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -843,7 +843,7 @@
}
/* 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;
@@ -851,12 +851,14 @@
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 06d3135b..a75ee30 100644
--- a/lib/debug_locks.c
+++ b/lib/debug_locks.c
@@ -36,7 +36,7 @@
/*
* 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) {
