* [PATCH 0/2] Add lockdep_assert_not_held() @ 2021-02-12 23:28 ` Shuah Khan 0 siblings, 0 replies; 20+ messages in thread From: Shuah Khan @ 2021-02-12 23:28 UTC (permalink / raw) To: peterz, mingo, will, kvalo, davem, kuba Cc: Shuah Khan, ath10k, linux-wireless, netdev, linux-kernel Some kernel functions must not be called holding a specific lock. Doing so could lead to locking problems. Currently these routines call lock_is_held() to check for lock hold followed by WARN_ON. Adding a common lockdep interface will help reduce the duplication of this logic in the rest of the kernel. Add lockdep_assert_not_held() to be used in these functions to detect incorrect calls while holding a lock. lockdep_assert_not_held() provides the opposite functionality of lockdep_assert_held() which is used to assert calls that require holding a specific lock. The need for lockdep_assert_not_held() came up in a discussion on ath10k patch. ath10k_drain_tx() and i915_vma_pin_ww() are examples of functions that can use lockdep_assert_not_held(). Link: https://lore.kernel.org/linux-wireless/871rdmu9z9.fsf@codeaurora.org/ This patch series adds lockdep_assert_not_held() and uses it in the second patch in ath10k_drain_tx() function. Shuah Khan (2): lockdep: add lockdep_assert_not_held() ath10k: detect conf_mutex held ath10k_drain_tx() calls drivers/net/wireless/ath/ath10k/mac.c | 2 ++ include/linux/lockdep.h | 7 ++++++- 2 files changed, 8 insertions(+), 1 deletion(-) -- 2.27.0 ^ permalink raw reply [flat|nested] 20+ messages in thread
* [PATCH 0/2] Add lockdep_assert_not_held() @ 2021-02-12 23:28 ` Shuah Khan 0 siblings, 0 replies; 20+ messages in thread From: Shuah Khan @ 2021-02-12 23:28 UTC (permalink / raw) To: peterz, mingo, will, kvalo, davem, kuba Cc: netdev, linux-wireless, linux-kernel, ath10k, Shuah Khan Some kernel functions must not be called holding a specific lock. Doing so could lead to locking problems. Currently these routines call lock_is_held() to check for lock hold followed by WARN_ON. Adding a common lockdep interface will help reduce the duplication of this logic in the rest of the kernel. Add lockdep_assert_not_held() to be used in these functions to detect incorrect calls while holding a lock. lockdep_assert_not_held() provides the opposite functionality of lockdep_assert_held() which is used to assert calls that require holding a specific lock. The need for lockdep_assert_not_held() came up in a discussion on ath10k patch. ath10k_drain_tx() and i915_vma_pin_ww() are examples of functions that can use lockdep_assert_not_held(). Link: https://lore.kernel.org/linux-wireless/871rdmu9z9.fsf@codeaurora.org/ This patch series adds lockdep_assert_not_held() and uses it in the second patch in ath10k_drain_tx() function. Shuah Khan (2): lockdep: add lockdep_assert_not_held() ath10k: detect conf_mutex held ath10k_drain_tx() calls drivers/net/wireless/ath/ath10k/mac.c | 2 ++ include/linux/lockdep.h | 7 ++++++- 2 files changed, 8 insertions(+), 1 deletion(-) -- 2.27.0 _______________________________________________ ath10k mailing list ath10k@lists.infradead.org http://lists.infradead.org/mailman/listinfo/ath10k ^ permalink raw reply [flat|nested] 20+ messages in thread
* [PATCH 1/2] lockdep: add lockdep_assert_not_held() 2021-02-12 23:28 ` Shuah Khan @ 2021-02-12 23:28 ` Shuah Khan -1 siblings, 0 replies; 20+ messages in thread From: Shuah Khan @ 2021-02-12 23:28 UTC (permalink / raw) To: peterz, mingo, will, kvalo, davem, kuba Cc: Shuah Khan, ath10k, linux-wireless, netdev, linux-kernel Some kernel functions must not be called holding a specific lock. Doing so could lead to locking problems. Currently these routines call lock_is_held() to check for lock hold followed by WARN_ON. Adding a common lockdep interface will help reduce the duplication of this logic in the rest of the kernel. Add lockdep_assert_not_held() to be used in these functions to detect incorrect calls while holding a lock. lockdep_assert_not_held() provides the opposite functionality of lockdep_assert_held() which is used to assert calls that require holding a specific lock. The need for lockdep_assert_not_held() came up in a discussion on ath10k patch. ath10k_drain_tx() and i915_vma_pin_ww() are examples of functions that can use lockdep_assert_not_held(). Link: https://lore.kernel.org/linux-wireless/871rdmu9z9.fsf@codeaurora.org/ Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> --- include/linux/lockdep.h | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index b9e9adec73e8..567e3a1a27ce 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -294,6 +294,10 @@ 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_not_held(l) do { \ + WARN_ON(debug_locks && lockdep_is_held(l)); \ + } while (0) + #define lockdep_assert_held(l) do { \ WARN_ON(debug_locks && !lockdep_is_held(l)); \ } while (0) @@ -383,8 +387,9 @@ extern int lock_is_held(const void *); extern int lockdep_is_held(const void *); #define lockdep_is_held_type(l, r) (1) +#define lockdep_assert_not_held(l) do { (void)(l); } while (0) #define lockdep_assert_held(l) do { (void)(l); } while (0) -#define lockdep_assert_held_write(l) do { (void)(l); } while (0) +#define lockdep_assert_held_write(l) do { (void)(l); } while (0) #define lockdep_assert_held_read(l) do { (void)(l); } while (0) #define lockdep_assert_held_once(l) do { (void)(l); } while (0) -- 2.27.0 ^ permalink raw reply related [flat|nested] 20+ messages in thread
* [PATCH 1/2] lockdep: add lockdep_assert_not_held() @ 2021-02-12 23:28 ` Shuah Khan 0 siblings, 0 replies; 20+ messages in thread From: Shuah Khan @ 2021-02-12 23:28 UTC (permalink / raw) To: peterz, mingo, will, kvalo, davem, kuba Cc: netdev, linux-wireless, linux-kernel, ath10k, Shuah Khan Some kernel functions must not be called holding a specific lock. Doing so could lead to locking problems. Currently these routines call lock_is_held() to check for lock hold followed by WARN_ON. Adding a common lockdep interface will help reduce the duplication of this logic in the rest of the kernel. Add lockdep_assert_not_held() to be used in these functions to detect incorrect calls while holding a lock. lockdep_assert_not_held() provides the opposite functionality of lockdep_assert_held() which is used to assert calls that require holding a specific lock. The need for lockdep_assert_not_held() came up in a discussion on ath10k patch. ath10k_drain_tx() and i915_vma_pin_ww() are examples of functions that can use lockdep_assert_not_held(). Link: https://lore.kernel.org/linux-wireless/871rdmu9z9.fsf@codeaurora.org/ Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> --- include/linux/lockdep.h | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index b9e9adec73e8..567e3a1a27ce 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -294,6 +294,10 @@ 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_not_held(l) do { \ + WARN_ON(debug_locks && lockdep_is_held(l)); \ + } while (0) + #define lockdep_assert_held(l) do { \ WARN_ON(debug_locks && !lockdep_is_held(l)); \ } while (0) @@ -383,8 +387,9 @@ extern int lock_is_held(const void *); extern int lockdep_is_held(const void *); #define lockdep_is_held_type(l, r) (1) +#define lockdep_assert_not_held(l) do { (void)(l); } while (0) #define lockdep_assert_held(l) do { (void)(l); } while (0) -#define lockdep_assert_held_write(l) do { (void)(l); } while (0) +#define lockdep_assert_held_write(l) do { (void)(l); } while (0) #define lockdep_assert_held_read(l) do { (void)(l); } while (0) #define lockdep_assert_held_once(l) do { (void)(l); } while (0) -- 2.27.0 _______________________________________________ ath10k mailing list ath10k@lists.infradead.org http://lists.infradead.org/mailman/listinfo/ath10k ^ permalink raw reply related [flat|nested] 20+ messages in thread
* Re: [PATCH 1/2] lockdep: add lockdep_assert_not_held() 2021-02-12 23:28 ` Shuah Khan @ 2021-02-14 17:53 ` Peter Zijlstra -1 siblings, 0 replies; 20+ messages in thread From: Peter Zijlstra @ 2021-02-14 17:53 UTC (permalink / raw) To: Shuah Khan Cc: mingo, will, kvalo, davem, kuba, ath10k, linux-wireless, netdev, linux-kernel On Fri, Feb 12, 2021 at 04:28:42PM -0700, Shuah Khan wrote: > +#define lockdep_assert_not_held(l) do { \ > + WARN_ON(debug_locks && lockdep_is_held(l)); \ > + } while (0) > + This thing isn't as straight forward as you might think, but it'll mostly work. Notably this thing will misfire when lockdep_off() is employed. It certainyl needs a comment to explain the subtleties. ^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH 1/2] lockdep: add lockdep_assert_not_held() @ 2021-02-14 17:53 ` Peter Zijlstra 0 siblings, 0 replies; 20+ messages in thread From: Peter Zijlstra @ 2021-02-14 17:53 UTC (permalink / raw) To: Shuah Khan Cc: netdev, linux-wireless, linux-kernel, ath10k, mingo, kuba, will, davem, kvalo On Fri, Feb 12, 2021 at 04:28:42PM -0700, Shuah Khan wrote: > +#define lockdep_assert_not_held(l) do { \ > + WARN_ON(debug_locks && lockdep_is_held(l)); \ > + } while (0) > + This thing isn't as straight forward as you might think, but it'll mostly work. Notably this thing will misfire when lockdep_off() is employed. It certainyl needs a comment to explain the subtleties. _______________________________________________ ath10k mailing list ath10k@lists.infradead.org http://lists.infradead.org/mailman/listinfo/ath10k ^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH 1/2] lockdep: add lockdep_assert_not_held() 2021-02-14 17:53 ` Peter Zijlstra @ 2021-02-15 10:44 ` Peter Zijlstra -1 siblings, 0 replies; 20+ messages in thread From: Peter Zijlstra @ 2021-02-15 10:44 UTC (permalink / raw) To: Shuah Khan Cc: mingo, will, kvalo, davem, kuba, ath10k, linux-wireless, netdev, linux-kernel On Sun, Feb 14, 2021 at 06:53:01PM +0100, Peter Zijlstra wrote: > On Fri, Feb 12, 2021 at 04:28:42PM -0700, Shuah Khan wrote: > > > +#define lockdep_assert_not_held(l) do { \ > > + WARN_ON(debug_locks && lockdep_is_held(l)); \ > > + } while (0) > > + > > This thing isn't as straight forward as you might think, but it'll > mostly work. > > Notably this thing will misfire when lockdep_off() is employed. It > certainyl needs a comment to explain the subtleties. I think something like so will work, but please double check. diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index b9e9adec73e8..c8b0d292bf8e 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -294,11 +294,15 @@ 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)); \ +#define lockdep_assert_held(l) do { \ + WARN_ON(debug_locks && lockdep_is_held(l) == 0)); \ } while (0) -#define lockdep_assert_held_write(l) do { \ +#define lockdep_assert_not_held(l) do { \ + WARN_ON(debug_locks && lockdep_is_held(l) == 1)); \ + } while (0) + +#define lockdep_assert_held_write(l) do { \ WARN_ON(debug_locks && !lockdep_is_held_type(l, 0)); \ } while (0) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index c1418b47f625..983ba206f7b2 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -5467,7 +5467,7 @@ noinstr int lock_is_held_type(const struct lockdep_map *lock, int read) int ret = 0; if (unlikely(!lockdep_enabled())) - return 1; /* avoid false negative lockdep_assert_held() */ + return -1; /* avoid false negative lockdep_assert_held() */ raw_local_irq_save(flags); check_flags(flags); ^ permalink raw reply related [flat|nested] 20+ messages in thread
* Re: [PATCH 1/2] lockdep: add lockdep_assert_not_held() @ 2021-02-15 10:44 ` Peter Zijlstra 0 siblings, 0 replies; 20+ messages in thread From: Peter Zijlstra @ 2021-02-15 10:44 UTC (permalink / raw) To: Shuah Khan Cc: netdev, linux-wireless, linux-kernel, ath10k, mingo, kuba, will, davem, kvalo On Sun, Feb 14, 2021 at 06:53:01PM +0100, Peter Zijlstra wrote: > On Fri, Feb 12, 2021 at 04:28:42PM -0700, Shuah Khan wrote: > > > +#define lockdep_assert_not_held(l) do { \ > > + WARN_ON(debug_locks && lockdep_is_held(l)); \ > > + } while (0) > > + > > This thing isn't as straight forward as you might think, but it'll > mostly work. > > Notably this thing will misfire when lockdep_off() is employed. It > certainyl needs a comment to explain the subtleties. I think something like so will work, but please double check. diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index b9e9adec73e8..c8b0d292bf8e 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -294,11 +294,15 @@ 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)); \ +#define lockdep_assert_held(l) do { \ + WARN_ON(debug_locks && lockdep_is_held(l) == 0)); \ } while (0) -#define lockdep_assert_held_write(l) do { \ +#define lockdep_assert_not_held(l) do { \ + WARN_ON(debug_locks && lockdep_is_held(l) == 1)); \ + } while (0) + +#define lockdep_assert_held_write(l) do { \ WARN_ON(debug_locks && !lockdep_is_held_type(l, 0)); \ } while (0) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index c1418b47f625..983ba206f7b2 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -5467,7 +5467,7 @@ noinstr int lock_is_held_type(const struct lockdep_map *lock, int read) int ret = 0; if (unlikely(!lockdep_enabled())) - return 1; /* avoid false negative lockdep_assert_held() */ + return -1; /* avoid false negative lockdep_assert_held() */ raw_local_irq_save(flags); check_flags(flags); _______________________________________________ ath10k mailing list ath10k@lists.infradead.org http://lists.infradead.org/mailman/listinfo/ath10k ^ permalink raw reply related [flat|nested] 20+ messages in thread
* Re: [PATCH 1/2] lockdep: add lockdep_assert_not_held() 2021-02-15 10:44 ` Peter Zijlstra @ 2021-02-15 13:12 ` Johannes Berg -1 siblings, 0 replies; 20+ messages in thread From: Johannes Berg @ 2021-02-15 13:12 UTC (permalink / raw) To: Peter Zijlstra, Shuah Khan Cc: mingo, will, kvalo, davem, kuba, ath10k, linux-wireless, netdev, linux-kernel On Mon, 2021-02-15 at 11:44 +0100, Peter Zijlstra wrote: > > I think something like so will work, but please double check. Yeah, that looks better. > +++ b/include/linux/lockdep.h > @@ -294,11 +294,15 @@ 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)); \ > +#define lockdep_assert_held(l) do { \ > + WARN_ON(debug_locks && lockdep_is_held(l) == 0)); \ > } while (0) That doesn't really need to change? It's the same. > -#define lockdep_assert_held_write(l) do { \ > +#define lockdep_assert_not_held(l) do { \ > + WARN_ON(debug_locks && lockdep_is_held(l) == 1)); \ > + } while (0) > + > +#define lockdep_assert_held_write(l) do { \ > WARN_ON(debug_locks && !lockdep_is_held_type(l, 0)); \ > } while (0) > > diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c > index c1418b47f625..983ba206f7b2 100644 > --- a/kernel/locking/lockdep. > +++ b/kernel/locking/lockdep.c > @@ -5467,7 +5467,7 @@ noinstr int lock_is_held_type(const struct lockdep_map *lock, int read) > int ret = 0; > > if (unlikely(!lockdep_enabled())) > - return 1; /* avoid false negative lockdep_assert_held() */ > + return -1; /* avoid false negative lockdep_assert_held() */ Maybe add lockdep_assert_not_held() to the comment, to explain the -1 (vs non-zero)? johannes ^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH 1/2] lockdep: add lockdep_assert_not_held() @ 2021-02-15 13:12 ` Johannes Berg 0 siblings, 0 replies; 20+ messages in thread From: Johannes Berg @ 2021-02-15 13:12 UTC (permalink / raw) To: Peter Zijlstra, Shuah Khan Cc: netdev, linux-wireless, linux-kernel, ath10k, mingo, kuba, will, davem, kvalo On Mon, 2021-02-15 at 11:44 +0100, Peter Zijlstra wrote: > > I think something like so will work, but please double check. Yeah, that looks better. > +++ b/include/linux/lockdep.h > @@ -294,11 +294,15 @@ 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)); \ > +#define lockdep_assert_held(l) do { \ > + WARN_ON(debug_locks && lockdep_is_held(l) == 0)); \ > } while (0) That doesn't really need to change? It's the same. > -#define lockdep_assert_held_write(l) do { \ > +#define lockdep_assert_not_held(l) do { \ > + WARN_ON(debug_locks && lockdep_is_held(l) == 1)); \ > + } while (0) > + > +#define lockdep_assert_held_write(l) do { \ > WARN_ON(debug_locks && !lockdep_is_held_type(l, 0)); \ > } while (0) > > diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c > index c1418b47f625..983ba206f7b2 100644 > --- a/kernel/locking/lockdep. > +++ b/kernel/locking/lockdep.c > @@ -5467,7 +5467,7 @@ noinstr int lock_is_held_type(const struct lockdep_map *lock, int read) > int ret = 0; > > if (unlikely(!lockdep_enabled())) > - return 1; /* avoid false negative lockdep_assert_held() */ > + return -1; /* avoid false negative lockdep_assert_held() */ Maybe add lockdep_assert_not_held() to the comment, to explain the -1 (vs non-zero)? johannes _______________________________________________ ath10k mailing list ath10k@lists.infradead.org http://lists.infradead.org/mailman/listinfo/ath10k ^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH 1/2] lockdep: add lockdep_assert_not_held() 2021-02-15 13:12 ` Johannes Berg @ 2021-02-15 16:04 ` Peter Zijlstra -1 siblings, 0 replies; 20+ messages in thread From: Peter Zijlstra @ 2021-02-15 16:04 UTC (permalink / raw) To: Johannes Berg Cc: Shuah Khan, mingo, will, kvalo, davem, kuba, ath10k, linux-wireless, netdev, linux-kernel On Mon, Feb 15, 2021 at 02:12:30PM +0100, Johannes Berg wrote: > On Mon, 2021-02-15 at 11:44 +0100, Peter Zijlstra wrote: > > > > I think something like so will work, but please double check. > > Yeah, that looks better. > > > +++ b/include/linux/lockdep.h > > @@ -294,11 +294,15 @@ 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)); \ > > +#define lockdep_assert_held(l) do { \ > > + WARN_ON(debug_locks && lockdep_is_held(l) == 0)); \ > > } while (0) > > That doesn't really need to change? It's the same. Correct, but I found it more symmetric vs the not implementation below. > > -#define lockdep_assert_held_write(l) do { \ > > +#define lockdep_assert_not_held(l) do { \ > > + WARN_ON(debug_locks && lockdep_is_held(l) == 1)); \ > > + } while (0) > > + > > +#define lockdep_assert_held_write(l) do { \ > > WARN_ON(debug_locks && !lockdep_is_held_type(l, 0)); \ > > } while (0) > > > > diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c > > index c1418b47f625..983ba206f7b2 100644 > > --- a/kernel/locking/lockdep. > > +++ b/kernel/locking/lockdep.c > > @@ -5467,7 +5467,7 @@ noinstr int lock_is_held_type(const struct lockdep_map *lock, int read) > > int ret = 0; > > > > if (unlikely(!lockdep_enabled())) > > - return 1; /* avoid false negative lockdep_assert_held() */ > > + return -1; /* avoid false negative lockdep_assert_held() */ > > Maybe add lockdep_assert_not_held() to the comment, to explain the -1 > (vs non-zero)? Yeah, or frob a '*' in there. ^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH 1/2] lockdep: add lockdep_assert_not_held() @ 2021-02-15 16:04 ` Peter Zijlstra 0 siblings, 0 replies; 20+ messages in thread From: Peter Zijlstra @ 2021-02-15 16:04 UTC (permalink / raw) To: Johannes Berg Cc: netdev, linux-wireless, linux-kernel, ath10k, mingo, Shuah Khan, kuba, will, davem, kvalo On Mon, Feb 15, 2021 at 02:12:30PM +0100, Johannes Berg wrote: > On Mon, 2021-02-15 at 11:44 +0100, Peter Zijlstra wrote: > > > > I think something like so will work, but please double check. > > Yeah, that looks better. > > > +++ b/include/linux/lockdep.h > > @@ -294,11 +294,15 @@ 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)); \ > > +#define lockdep_assert_held(l) do { \ > > + WARN_ON(debug_locks && lockdep_is_held(l) == 0)); \ > > } while (0) > > That doesn't really need to change? It's the same. Correct, but I found it more symmetric vs the not implementation below. > > -#define lockdep_assert_held_write(l) do { \ > > +#define lockdep_assert_not_held(l) do { \ > > + WARN_ON(debug_locks && lockdep_is_held(l) == 1)); \ > > + } while (0) > > + > > +#define lockdep_assert_held_write(l) do { \ > > WARN_ON(debug_locks && !lockdep_is_held_type(l, 0)); \ > > } while (0) > > > > diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c > > index c1418b47f625..983ba206f7b2 100644 > > --- a/kernel/locking/lockdep. > > +++ b/kernel/locking/lockdep.c > > @@ -5467,7 +5467,7 @@ noinstr int lock_is_held_type(const struct lockdep_map *lock, int read) > > int ret = 0; > > > > if (unlikely(!lockdep_enabled())) > > - return 1; /* avoid false negative lockdep_assert_held() */ > > + return -1; /* avoid false negative lockdep_assert_held() */ > > Maybe add lockdep_assert_not_held() to the comment, to explain the -1 > (vs non-zero)? Yeah, or frob a '*' in there. _______________________________________________ ath10k mailing list ath10k@lists.infradead.org http://lists.infradead.org/mailman/listinfo/ath10k ^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH 1/2] lockdep: add lockdep_assert_not_held() 2021-02-15 16:04 ` Peter Zijlstra @ 2021-02-15 16:10 ` Johannes Berg -1 siblings, 0 replies; 20+ messages in thread From: Johannes Berg @ 2021-02-15 16:10 UTC (permalink / raw) To: Peter Zijlstra Cc: Shuah Khan, mingo, will, kvalo, davem, kuba, ath10k, linux-wireless, netdev, linux-kernel On Mon, 2021-02-15 at 17:04 +0100, Peter Zijlstra wrote: > On Mon, Feb 15, 2021 at 02:12:30PM +0100, Johannes Berg wrote: > > On Mon, 2021-02-15 at 11:44 +0100, Peter Zijlstra wrote: > > > I think something like so will work, but please double check. > > > > Yeah, that looks better. > > > > > +++ b/include/linux/lockdep.h > > > @@ -294,11 +294,15 @@ 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)); \ > > > +#define lockdep_assert_held(l) do { \ > > > + WARN_ON(debug_locks && lockdep_is_held(l) == 0)); \ > > > } while (0) > > > > That doesn't really need to change? It's the same. > > Correct, but I found it more symmetric vs the not implementation below. Fair enough. One might argue that you should have an enum lockdep_lock_state { LOCK_STATE_NOT_HELD, /* 0 now */ LOCK_STATE_HELD, /* 1 now */ LOCK_STATE_UNKNOWN, /* -1 with your patch but might as well be 2 */ }; :) johannes ^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH 1/2] lockdep: add lockdep_assert_not_held() @ 2021-02-15 16:10 ` Johannes Berg 0 siblings, 0 replies; 20+ messages in thread From: Johannes Berg @ 2021-02-15 16:10 UTC (permalink / raw) To: Peter Zijlstra Cc: netdev, linux-wireless, linux-kernel, ath10k, mingo, Shuah Khan, kuba, will, davem, kvalo On Mon, 2021-02-15 at 17:04 +0100, Peter Zijlstra wrote: > On Mon, Feb 15, 2021 at 02:12:30PM +0100, Johannes Berg wrote: > > On Mon, 2021-02-15 at 11:44 +0100, Peter Zijlstra wrote: > > > I think something like so will work, but please double check. > > > > Yeah, that looks better. > > > > > +++ b/include/linux/lockdep.h > > > @@ -294,11 +294,15 @@ 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)); \ > > > +#define lockdep_assert_held(l) do { \ > > > + WARN_ON(debug_locks && lockdep_is_held(l) == 0)); \ > > > } while (0) > > > > That doesn't really need to change? It's the same. > > Correct, but I found it more symmetric vs the not implementation below. Fair enough. One might argue that you should have an enum lockdep_lock_state { LOCK_STATE_NOT_HELD, /* 0 now */ LOCK_STATE_HELD, /* 1 now */ LOCK_STATE_UNKNOWN, /* -1 with your patch but might as well be 2 */ }; :) johannes _______________________________________________ ath10k mailing list ath10k@lists.infradead.org http://lists.infradead.org/mailman/listinfo/ath10k ^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH 1/2] lockdep: add lockdep_assert_not_held() 2021-02-15 16:10 ` Johannes Berg @ 2021-02-22 20:51 ` Shuah Khan -1 siblings, 0 replies; 20+ messages in thread From: Shuah Khan @ 2021-02-22 20:51 UTC (permalink / raw) To: Johannes Berg, Peter Zijlstra Cc: mingo, will, kvalo, davem, kuba, ath10k, linux-wireless, netdev, linux-kernel, Shuah Khan On 2/15/21 9:10 AM, Johannes Berg wrote: > On Mon, 2021-02-15 at 17:04 +0100, Peter Zijlstra wrote: >> On Mon, Feb 15, 2021 at 02:12:30PM +0100, Johannes Berg wrote: >>> On Mon, 2021-02-15 at 11:44 +0100, Peter Zijlstra wrote: >>>> I think something like so will work, but please double check. >>> >>> Yeah, that looks better. >>> >>>> +++ b/include/linux/lockdep.h >>>> @@ -294,11 +294,15 @@ 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)); \ >>>> +#define lockdep_assert_held(l) do { \ >>>> + WARN_ON(debug_locks && lockdep_is_held(l) == 0)); \ >>>> } while (0) >>> >>> That doesn't really need to change? It's the same. >> >> Correct, but I found it more symmetric vs the not implementation below. > > Fair enough. One might argue that you should have an > > enum lockdep_lock_state { > LOCK_STATE_NOT_HELD, /* 0 now */ > LOCK_STATE_HELD, /* 1 now */ > LOCK_STATE_UNKNOWN, /* -1 with your patch but might as well be 2 */ > }; > > :) > Thank you both. Picking this back up. Will send v2 incorporating your comments and suggestions. thanks, -- Shuah ^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH 1/2] lockdep: add lockdep_assert_not_held() @ 2021-02-22 20:51 ` Shuah Khan 0 siblings, 0 replies; 20+ messages in thread From: Shuah Khan @ 2021-02-22 20:51 UTC (permalink / raw) To: Johannes Berg, Peter Zijlstra Cc: netdev, linux-wireless, linux-kernel, ath10k, mingo, Shuah Khan, kuba, will, davem, kvalo On 2/15/21 9:10 AM, Johannes Berg wrote: > On Mon, 2021-02-15 at 17:04 +0100, Peter Zijlstra wrote: >> On Mon, Feb 15, 2021 at 02:12:30PM +0100, Johannes Berg wrote: >>> On Mon, 2021-02-15 at 11:44 +0100, Peter Zijlstra wrote: >>>> I think something like so will work, but please double check. >>> >>> Yeah, that looks better. >>> >>>> +++ b/include/linux/lockdep.h >>>> @@ -294,11 +294,15 @@ 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)); \ >>>> +#define lockdep_assert_held(l) do { \ >>>> + WARN_ON(debug_locks && lockdep_is_held(l) == 0)); \ >>>> } while (0) >>> >>> That doesn't really need to change? It's the same. >> >> Correct, but I found it more symmetric vs the not implementation below. > > Fair enough. One might argue that you should have an > > enum lockdep_lock_state { > LOCK_STATE_NOT_HELD, /* 0 now */ > LOCK_STATE_HELD, /* 1 now */ > LOCK_STATE_UNKNOWN, /* -1 with your patch but might as well be 2 */ > }; > > :) > Thank you both. Picking this back up. Will send v2 incorporating your comments and suggestions. thanks, -- Shuah _______________________________________________ ath10k mailing list ath10k@lists.infradead.org http://lists.infradead.org/mailman/listinfo/ath10k ^ permalink raw reply [flat|nested] 20+ messages in thread
* [PATCH 2/2] ath10k: detect conf_mutex held ath10k_drain_tx() calls 2021-02-12 23:28 ` Shuah Khan @ 2021-02-12 23:28 ` Shuah Khan -1 siblings, 0 replies; 20+ messages in thread From: Shuah Khan @ 2021-02-12 23:28 UTC (permalink / raw) To: peterz, mingo, will, kvalo, davem, kuba Cc: Shuah Khan, ath10k, linux-wireless, netdev, linux-kernel ath10k_drain_tx() must not be called with conf_mutex held as workers can use that also. Add call to lockdep_assert_not_held() on conf_mutex to detect if conf_mutex is held by the caller. The idea for this patch stemmed from coming across the comment block above the ath10k_drain_tx() while reviewing the conf_mutex holds during to debug the conf_mutex lock assert in ath10k_debug_fw_stats_request(). Adding detection to assert on conf_mutex hold will help detect incorrect usages that could lead to locking problems when async worker routines try to call this routine. Link: https://lore.kernel.org/linux-wireless/871rdmu9z9.fsf@codeaurora.org/ Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> --- drivers/net/wireless/ath/ath10k/mac.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/wireless/ath/ath10k/mac.c b/drivers/net/wireless/ath/ath10k/mac.c index c202b167d8c6..7de05b679ad2 100644 --- a/drivers/net/wireless/ath/ath10k/mac.c +++ b/drivers/net/wireless/ath/ath10k/mac.c @@ -4728,6 +4728,8 @@ static void ath10k_mac_op_wake_tx_queue(struct ieee80211_hw *hw, /* Must not be called with conf_mutex held as workers can use that also. */ void ath10k_drain_tx(struct ath10k *ar) { + lockdep_assert_not_held(&ar->conf_mutex); + /* make sure rcu-protected mac80211 tx path itself is drained */ synchronize_net(); -- 2.27.0 ^ permalink raw reply related [flat|nested] 20+ messages in thread
* [PATCH 2/2] ath10k: detect conf_mutex held ath10k_drain_tx() calls @ 2021-02-12 23:28 ` Shuah Khan 0 siblings, 0 replies; 20+ messages in thread From: Shuah Khan @ 2021-02-12 23:28 UTC (permalink / raw) To: peterz, mingo, will, kvalo, davem, kuba Cc: netdev, linux-wireless, linux-kernel, ath10k, Shuah Khan ath10k_drain_tx() must not be called with conf_mutex held as workers can use that also. Add call to lockdep_assert_not_held() on conf_mutex to detect if conf_mutex is held by the caller. The idea for this patch stemmed from coming across the comment block above the ath10k_drain_tx() while reviewing the conf_mutex holds during to debug the conf_mutex lock assert in ath10k_debug_fw_stats_request(). Adding detection to assert on conf_mutex hold will help detect incorrect usages that could lead to locking problems when async worker routines try to call this routine. Link: https://lore.kernel.org/linux-wireless/871rdmu9z9.fsf@codeaurora.org/ Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> --- drivers/net/wireless/ath/ath10k/mac.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/wireless/ath/ath10k/mac.c b/drivers/net/wireless/ath/ath10k/mac.c index c202b167d8c6..7de05b679ad2 100644 --- a/drivers/net/wireless/ath/ath10k/mac.c +++ b/drivers/net/wireless/ath/ath10k/mac.c @@ -4728,6 +4728,8 @@ static void ath10k_mac_op_wake_tx_queue(struct ieee80211_hw *hw, /* Must not be called with conf_mutex held as workers can use that also. */ void ath10k_drain_tx(struct ath10k *ar) { + lockdep_assert_not_held(&ar->conf_mutex); + /* make sure rcu-protected mac80211 tx path itself is drained */ synchronize_net(); -- 2.27.0 _______________________________________________ ath10k mailing list ath10k@lists.infradead.org http://lists.infradead.org/mailman/listinfo/ath10k ^ permalink raw reply related [flat|nested] 20+ messages in thread
* Re: [PATCH 2/2] ath10k: detect conf_mutex held ath10k_drain_tx() calls 2021-02-12 23:28 ` Shuah Khan @ 2021-02-14 6:08 ` Kalle Valo -1 siblings, 0 replies; 20+ messages in thread From: Kalle Valo @ 2021-02-14 6:08 UTC (permalink / raw) To: Shuah Khan Cc: peterz, mingo, will, davem, kuba, ath10k, linux-wireless, netdev, linux-kernel Shuah Khan <skhan@linuxfoundation.org> writes: > ath10k_drain_tx() must not be called with conf_mutex held as workers can > use that also. Add call to lockdep_assert_not_held() on conf_mutex to > detect if conf_mutex is held by the caller. > > The idea for this patch stemmed from coming across the comment block > above the ath10k_drain_tx() while reviewing the conf_mutex holds during > to debug the conf_mutex lock assert in ath10k_debug_fw_stats_request(). > > Adding detection to assert on conf_mutex hold will help detect incorrect > usages that could lead to locking problems when async worker routines try > to call this routine. > > Link: https://lore.kernel.org/linux-wireless/871rdmu9z9.fsf@codeaurora.org/ > Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> This can go via the same tree as patch 1: Acked-by: Kalle Valo <kvalo@codeaurora.org> But I can also take this to my ath tree, once patch 1 has reached it. Just let me know what is preferred. -- https://patchwork.kernel.org/project/linux-wireless/list/ https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches ^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH 2/2] ath10k: detect conf_mutex held ath10k_drain_tx() calls @ 2021-02-14 6:08 ` Kalle Valo 0 siblings, 0 replies; 20+ messages in thread From: Kalle Valo @ 2021-02-14 6:08 UTC (permalink / raw) To: Shuah Khan Cc: peterz, netdev, linux-wireless, linux-kernel, ath10k, mingo, kuba, will, davem Shuah Khan <skhan@linuxfoundation.org> writes: > ath10k_drain_tx() must not be called with conf_mutex held as workers can > use that also. Add call to lockdep_assert_not_held() on conf_mutex to > detect if conf_mutex is held by the caller. > > The idea for this patch stemmed from coming across the comment block > above the ath10k_drain_tx() while reviewing the conf_mutex holds during > to debug the conf_mutex lock assert in ath10k_debug_fw_stats_request(). > > Adding detection to assert on conf_mutex hold will help detect incorrect > usages that could lead to locking problems when async worker routines try > to call this routine. > > Link: https://lore.kernel.org/linux-wireless/871rdmu9z9.fsf@codeaurora.org/ > Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> This can go via the same tree as patch 1: Acked-by: Kalle Valo <kvalo@codeaurora.org> But I can also take this to my ath tree, once patch 1 has reached it. Just let me know what is preferred. -- https://patchwork.kernel.org/project/linux-wireless/list/ https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches _______________________________________________ ath10k mailing list ath10k@lists.infradead.org http://lists.infradead.org/mailman/listinfo/ath10k ^ permalink raw reply [flat|nested] 20+ messages in thread
end of thread, other threads:[~2021-02-22 20:52 UTC | newest] Thread overview: 20+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-02-12 23:28 [PATCH 0/2] Add lockdep_assert_not_held() Shuah Khan 2021-02-12 23:28 ` Shuah Khan 2021-02-12 23:28 ` [PATCH 1/2] lockdep: add lockdep_assert_not_held() Shuah Khan 2021-02-12 23:28 ` Shuah Khan 2021-02-14 17:53 ` Peter Zijlstra 2021-02-14 17:53 ` Peter Zijlstra 2021-02-15 10:44 ` Peter Zijlstra 2021-02-15 10:44 ` Peter Zijlstra 2021-02-15 13:12 ` Johannes Berg 2021-02-15 13:12 ` Johannes Berg 2021-02-15 16:04 ` Peter Zijlstra 2021-02-15 16:04 ` Peter Zijlstra 2021-02-15 16:10 ` Johannes Berg 2021-02-15 16:10 ` Johannes Berg 2021-02-22 20:51 ` Shuah Khan 2021-02-22 20:51 ` Shuah Khan 2021-02-12 23:28 ` [PATCH 2/2] ath10k: detect conf_mutex held ath10k_drain_tx() calls Shuah Khan 2021-02-12 23:28 ` Shuah Khan 2021-02-14 6:08 ` Kalle Valo 2021-02-14 6:08 ` Kalle Valo
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