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lockdep: Add lockdep lock state defines
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Adds defines for lock state returns from lock_is_held_type() based on
Johannes Berg's suggestions as it make it easier to read and maintain
the lock states. These are defines and a enum to avoid changes to
lock_is_held_type() and lockdep_is_held() return types.

Updates to lock_is_held_type() and  __lock_is_held() to use the new
defines.

Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/linux-wireless/871rdmu9z9.fsf@codeaurora.org/
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Shuah Khan authored and Ingo Molnar committed Mar 6, 2021
1 parent 3e31f94 commit f8cfa46
Showing 2 changed files with 15 additions and 7 deletions.
11 changes: 9 additions & 2 deletions include/linux/lockdep.h
Original file line number Diff line number Diff line change
@@ -268,6 +268,11 @@ extern void lock_acquire(struct lockdep_map *lock, unsigned int subclass,

extern void lock_release(struct lockdep_map *lock, unsigned long ip);

/* lock_is_held_type() returns */
#define LOCK_STATE_UNKNOWN -1
#define LOCK_STATE_NOT_HELD 0
#define LOCK_STATE_HELD 1

/*
* Same "read" as for lock_acquire(), except -1 means any.
*/
@@ -302,11 +307,13 @@ extern void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie);
#define lockdep_depth(tsk) (debug_locks ? (tsk)->lockdep_depth : 0)

#define lockdep_assert_held(l) do { \
WARN_ON(debug_locks && lockdep_is_held(l) == 0); \
WARN_ON(debug_locks && \
lockdep_is_held(l) == LOCK_STATE_NOT_HELD); \
} while (0)

#define lockdep_assert_not_held(l) do { \
WARN_ON(debug_locks && lockdep_is_held(l) == 1); \
WARN_ON(debug_locks && \
lockdep_is_held(l) == LOCK_STATE_HELD); \
} while (0)

#define lockdep_assert_held_write(l) do { \
11 changes: 6 additions & 5 deletions kernel/locking/lockdep.c
Original file line number Diff line number Diff line change
@@ -54,6 +54,7 @@
#include <linux/nmi.h>
#include <linux/rcupdate.h>
#include <linux/kprobes.h>
#include <linux/lockdep.h>

#include <asm/sections.h>

@@ -5252,13 +5253,13 @@ int __lock_is_held(const struct lockdep_map *lock, int read)

if (match_held_lock(hlock, lock)) {
if (read == -1 || hlock->read == read)
return 1;
return LOCK_STATE_HELD;

return 0;
return LOCK_STATE_NOT_HELD;
}
}

return 0;
return LOCK_STATE_NOT_HELD;
}

static struct pin_cookie __lock_pin_lock(struct lockdep_map *lock)
@@ -5537,14 +5538,14 @@ EXPORT_SYMBOL_GPL(lock_release);
noinstr int lock_is_held_type(const struct lockdep_map *lock, int read)
{
unsigned long flags;
int ret = 0;
int ret = LOCK_STATE_NOT_HELD;

/*
* Avoid false negative lockdep_assert_held() and
* lockdep_assert_not_held().
*/
if (unlikely(!lockdep_enabled()))
return -1;
return LOCK_STATE_UNKNOWN;

raw_local_irq_save(flags);
check_flags(flags);

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