Re: [PATCH] dma-buf: fix debugfs versus rcu and fence dumping
Hi Jérôme, I love your patch! Perhaps something to improve: [auto build test WARNING on linus/master] [also build test WARNING on v4.20-rc6 next-20181214] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system] url: https://github.com/0day-ci/linux/commits/jglisse-redhat-com/dma-buf-fix-debugfs-versus-rcu-and-fence-dumping/20181206-205935 config: x86_64-allmodconfig (attached as .config) compiler: gcc-7 (Debian 7.3.0-1) 7.3.0 reproduce: # save the attached .config to linux build tree make ARCH=x86_64 All warnings (new ones prefixed by >>): include/linux/slab.h:332:43: warning: dubious: x & !y include/linux/slab.h:332:43: warning: dubious: x & !y >> drivers/dma-buf/dma-buf.c:1031:9: warning: context imbalance in >> 'dma_buf_debug_show' - different lock contexts for basic block vim +/dma_buf_debug_show +1031 drivers/dma-buf/dma-buf.c b89e3563 drivers/base/dma-buf.cSumit Semwal 2013-04-04 1008 b89e3563 drivers/base/dma-buf.cSumit Semwal 2013-04-04 1009 #ifdef CONFIG_DEBUG_FS eb0b947e drivers/dma-buf/dma-buf.c Mathias Krause 2016-06-19 1010 static int dma_buf_debug_show(struct seq_file *s, void *unused) b89e3563 drivers/base/dma-buf.cSumit Semwal 2013-04-04 1011 { b89e3563 drivers/base/dma-buf.cSumit Semwal 2013-04-04 1012 int ret; b89e3563 drivers/base/dma-buf.cSumit Semwal 2013-04-04 1013 struct dma_buf *buf_obj; b89e3563 drivers/base/dma-buf.cSumit Semwal 2013-04-04 1014 struct dma_buf_attachment *attach_obj; 5eb2c72c drivers/dma-buf/dma-buf.c Russell King 2017-03-31 1015 struct reservation_object *robj; 5eb2c72c drivers/dma-buf/dma-buf.c Russell King 2017-03-31 1016 struct reservation_object_list *fobj; 5eb2c72c drivers/dma-buf/dma-buf.c Russell King 2017-03-31 1017 struct dma_fence *fence; 5eb2c72c drivers/dma-buf/dma-buf.c Russell King 2017-03-31 1018 unsigned seq; 5eb2c72c drivers/dma-buf/dma-buf.c Russell King 2017-03-31 1019 int count = 0, attach_count, shared_count, i; b89e3563 drivers/base/dma-buf.cSumit Semwal 2013-04-04 1020 size_t size = 0; b89e3563 drivers/base/dma-buf.cSumit Semwal 2013-04-04 1021 b89e3563 drivers/base/dma-buf.cSumit Semwal 2013-04-04 1022 ret = mutex_lock_interruptible(&db_list.lock); b89e3563 drivers/base/dma-buf.cSumit Semwal 2013-04-04 1023 b89e3563 drivers/base/dma-buf.cSumit Semwal 2013-04-04 1024 if (ret) b89e3563 drivers/base/dma-buf.cSumit Semwal 2013-04-04 1025 return ret; b89e3563 drivers/base/dma-buf.cSumit Semwal 2013-04-04 1026 c0b00a52 drivers/base/dma-buf.cSumit Semwal 2014-02-03 1027 seq_puts(s, "\nDma-buf Objects:\n"); da6c8f5e drivers/dma-buf/dma-buf.c Russell King 2017-03-31 1028 seq_printf(s, "%-8s\t%-8s\t%-8s\t%-8s\texp_name\n", da6c8f5e drivers/dma-buf/dma-buf.c Russell King 2017-03-31 1029 "size", "flags", "mode", "count"); b89e3563 drivers/base/dma-buf.cSumit Semwal 2013-04-04 1030 b89e3563 drivers/base/dma-buf.cSumit Semwal 2013-04-04 @1031 list_for_each_entry(buf_obj, &db_list.head, list_node) { b89e3563 drivers/base/dma-buf.cSumit Semwal 2013-04-04 1032 ret = mutex_lock_interruptible(&buf_obj->lock); b89e3563 drivers/base/dma-buf.cSumit Semwal 2013-04-04 1033 b89e3563 drivers/base/dma-buf.cSumit Semwal 2013-04-04 1034 if (ret) { c0b00a52 drivers/base/dma-buf.cSumit Semwal 2014-02-03 1035 seq_puts(s, b89e3563 drivers/base/dma-buf.cSumit Semwal 2013-04-04 1036 "\tERROR locking buffer object: skipping\n"); b89e3563 drivers/base/dma-buf.cSumit Semwal 2013-04-04 1037 continue; b89e3563 drivers/base/dma-buf.cSumit Semwal 2013-04-04 1038 } b89e3563 drivers/base/dma-buf.cSumit Semwal 2013-04-04 1039 c0b00a52 drivers/base/dma-buf.cSumit Semwal 2014-02-03 1040 seq_printf(s, "%08zu\t%08x\t%08x\t%08ld\t%s\n", c0b00a52 drivers/base/dma-buf.cSumit Semwal 2014-02-03 1041 buf_obj->size, b89e3563 drivers/base/dma-buf.cSumit Semwal 2013-04-04 1042 buf_obj->file->f_flags, buf_obj->file->f_mode, a1f6dbac drivers/dma-buf/dma-buf.c Al Viro2014-08-20 1043 file_count(buf_obj->file), c0b00a52 drivers/base/dma-buf.cSumit Semwal 2014-02-03 1044 buf_obj->exp_name); b89e3563 drivers/base/dma-buf.cSumit Semwal 2013-04-04 1045 5eb2c72c drivers/dma-buf/dma-buf.c Russell King 2017-03-31 1046 robj = buf_obj->resv; 5eb2c72c drivers/dma-buf/dma-buf.c Russell King 2017-03-31 1047 while (true) { 5eb2c72c drivers/dma-buf/dma-buf.c Russell King 2017-03-31 1048
Re: [PATCH] dma-buf: fix debugfs versus rcu and fence dumping
Hi, [This is an automated email] This commit has been processed because it contains a -stable tag. The stable tag indicates that it's relevant for the following trees: all The bot has tested the following trees: v4.19.7, v4.14.86, v4.9.143, v4.4.166, v3.18.128, v4.19.7: Build OK! v4.14.86: Build OK! v4.9.143: Failed to apply! Possible dependencies: 5eb2c72c8acc ("dma-buf: fence debugging") v4.4.166: Failed to apply! Possible dependencies: 5eb2c72c8acc ("dma-buf: fence debugging") v3.18.128: Failed to apply! Possible dependencies: 5eb2c72c8acc ("dma-buf: fence debugging") How should we proceed with this patch? -- Thanks, Sasha ___ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
Re: [PATCH] dma-buf: fix debugfs versus rcu and fence dumping v2
Hi, [This is an automated email] This commit has been processed because it contains a -stable tag. The stable tag indicates that it's relevant for the following trees: all The bot has tested the following trees: v4.19.7, v4.14.86, v4.9.143, v4.4.166, v3.18.128, v4.19.7: Build OK! v4.14.86: Build OK! v4.9.143: Failed to apply! Possible dependencies: 5eb2c72c8acc ("dma-buf: fence debugging") v4.4.166: Failed to apply! Possible dependencies: 5eb2c72c8acc ("dma-buf: fence debugging") v3.18.128: Failed to apply! Possible dependencies: 5eb2c72c8acc ("dma-buf: fence debugging") How should we proceed with this patch? -- Thanks, Sasha ___ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
Re: [PATCH] dma-buf: fix debugfs versus rcu and fence dumping v2
Am 06.12.18 um 17:58 schrieb Chris Wilson: > Quoting jgli...@redhat.com (2018-12-06 15:47:04) >> From: Jérôme Glisse >> >> The debugfs take reference on fence without dropping them. Also the >> rcu section are not well balance. Fix all that ... > Wouldn't the code be a lot simpler (and a consistent snapshot) if it used > reservation_object_get_fences_rcu()? Yeah, thought about that as well. Or even better move that code into reservation_object.c as reservation_object_show_fences() or something like that. Christian. > -Chris ___ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
Re: [PATCH] dma-buf: fix debugfs versus rcu and fence dumping v2
Quoting jgli...@redhat.com (2018-12-06 15:47:04) > From: Jérôme Glisse > > The debugfs take reference on fence without dropping them. Also the > rcu section are not well balance. Fix all that ... Wouldn't the code be a lot simpler (and a consistent snapshot) if it used reservation_object_get_fences_rcu()? -Chris ___ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
Re: [PATCH] dma-buf: fix debugfs versus rcu and fence dumping
On Thu, Dec 06, 2018 at 04:08:12PM +, Koenig, Christian wrote: > Am 06.12.18 um 16:21 schrieb Jerome Glisse: > > On Thu, Dec 06, 2018 at 08:09:28AM +, Koenig, Christian wrote: > >> Am 06.12.18 um 02:41 schrieb jgli...@redhat.com: > >>> From: Jérôme Glisse > >>> > >>> The debugfs take reference on fence without dropping them. Also the > >>> rcu section are not well balance. Fix all that ... > >>> > >>> Signed-off-by: Jérôme Glisse > >>> Cc: Christian König > >>> Cc: Daniel Vetter > >>> Cc: Sumit Semwal > >>> Cc: linux-me...@vger.kernel.org > >>> Cc: dri-devel@lists.freedesktop.org > >>> Cc: linaro-mm-...@lists.linaro.org > >>> Cc: Stéphane Marchesin > >>> Cc: sta...@vger.kernel.org > >> Well NAK, you are now taking the RCU lock twice and dropping the RCU and > >> still accessing fobj has a huge potential for accessing freed up memory. > >> > >> The only correct thing I can see here is to grab a reference to the > >> fence before printing any info on it, > >> Christian. > > Hu ? That is exactly what i am doing, take reference under rcu, > > rcu_unlock print the fence info, drop the fence reference, rcu > > lock rinse and repeat ... > > > > Note that the fobj in _existing_ code is access outside the rcu > > end that there is an rcu imbalance in that code ie a lonlely > > rcu_unlock after the for loop. > > > > So that the existing code is broken. > > No, the existing code is perfectly fine. > > Please note the break in the loop before the rcu_unlock(); > > if (!read_seqcount_retry(&robj->seq, seq)) > > break; <- HERE! > > rcu_read_unlock(); > > } > > So your patch breaks that and take the RCU read lock twice. Ok missed that, i wonder if the refcount in balance explains the crash that was reported to me ... i sent a patch just for that. Thank you for reviewing and pointing out the code i was oblivious too :) Cheers, Jérôme ___ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
Re: [PATCH] dma-buf: fix debugfs versus rcu and fence dumping
Am 06.12.18 um 16:21 schrieb Jerome Glisse: > On Thu, Dec 06, 2018 at 08:09:28AM +, Koenig, Christian wrote: >> Am 06.12.18 um 02:41 schrieb jgli...@redhat.com: >>> From: Jérôme Glisse >>> >>> The debugfs take reference on fence without dropping them. Also the >>> rcu section are not well balance. Fix all that ... >>> >>> Signed-off-by: Jérôme Glisse >>> Cc: Christian König >>> Cc: Daniel Vetter >>> Cc: Sumit Semwal >>> Cc: linux-me...@vger.kernel.org >>> Cc: dri-devel@lists.freedesktop.org >>> Cc: linaro-mm-...@lists.linaro.org >>> Cc: Stéphane Marchesin >>> Cc: sta...@vger.kernel.org >> Well NAK, you are now taking the RCU lock twice and dropping the RCU and >> still accessing fobj has a huge potential for accessing freed up memory. >> >> The only correct thing I can see here is to grab a reference to the >> fence before printing any info on it, >> Christian. > Hu ? That is exactly what i am doing, take reference under rcu, > rcu_unlock print the fence info, drop the fence reference, rcu > lock rinse and repeat ... > > Note that the fobj in _existing_ code is access outside the rcu > end that there is an rcu imbalance in that code ie a lonlely > rcu_unlock after the for loop. > > So that the existing code is broken. No, the existing code is perfectly fine. Please note the break in the loop before the rcu_unlock(); > if (!read_seqcount_retry(&robj->seq, seq)) > break; <- HERE! > rcu_read_unlock(); > } So your patch breaks that and take the RCU read lock twice. Regards, Christian. > >>> --- >>>drivers/dma-buf/dma-buf.c | 11 +-- >>>1 file changed, 9 insertions(+), 2 deletions(-) >>> >>> diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c >>> index 13884474d158..f6f4de42ac49 100644 >>> --- a/drivers/dma-buf/dma-buf.c >>> +++ b/drivers/dma-buf/dma-buf.c >>> @@ -1051,24 +1051,31 @@ static int dma_buf_debug_show(struct seq_file *s, >>> void *unused) >>> fobj = rcu_dereference(robj->fence); >>> shared_count = fobj ? fobj->shared_count : 0; >>> fence = rcu_dereference(robj->fence_excl); >>> + fence = dma_fence_get_rcu(fence); >>> if (!read_seqcount_retry(&robj->seq, seq)) >>> break; >>> rcu_read_unlock(); >>> } >>> - >>> - if (fence) >>> + if (fence) { >>> seq_printf(s, "\tExclusive fence: %s %s %ssignalled\n", >>>fence->ops->get_driver_name(fence), >>>fence->ops->get_timeline_name(fence), >>>dma_fence_is_signaled(fence) ? "" : "un"); >>> + dma_fence_put(fence); >>> + } >>> + >>> + rcu_read_lock(); >>> for (i = 0; i < shared_count; i++) { >>> fence = rcu_dereference(fobj->shared[i]); >>> if (!dma_fence_get_rcu(fence)) >>> continue; >>> + rcu_read_unlock(); >>> seq_printf(s, "\tShared fence: %s %s %ssignalled\n", >>>fence->ops->get_driver_name(fence), >>>fence->ops->get_timeline_name(fence), >>>dma_fence_is_signaled(fence) ? "" : "un"); >>> + dma_fence_put(fence); >>> + rcu_read_lock(); >>> } >>> rcu_read_unlock(); >>> ___ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
[PATCH] dma-buf: fix debugfs versus rcu and fence dumping v2
From: Jérôme Glisse The debugfs take reference on fence without dropping them. Also the rcu section are not well balance. Fix all that ... Changed since v1: - moved fobj logic around to be rcu safe Signed-off-by: Jérôme Glisse Cc: Christian König Cc: Daniel Vetter Cc: Sumit Semwal Cc: linux-me...@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linaro-mm-...@lists.linaro.org Cc: Stéphane Marchesin Cc: sta...@vger.kernel.org --- drivers/dma-buf/dma-buf.c | 21 - 1 file changed, 16 insertions(+), 5 deletions(-) diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index 13884474d158..9688d99894d6 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -1048,27 +1048,38 @@ static int dma_buf_debug_show(struct seq_file *s, void *unused) while (true) { seq = read_seqcount_begin(&robj->seq); rcu_read_lock(); - fobj = rcu_dereference(robj->fence); - shared_count = fobj ? fobj->shared_count : 0; fence = rcu_dereference(robj->fence_excl); + fence = dma_fence_get_rcu(fence); if (!read_seqcount_retry(&robj->seq, seq)) break; rcu_read_unlock(); } - - if (fence) + if (fence) { seq_printf(s, "\tExclusive fence: %s %s %ssignalled\n", fence->ops->get_driver_name(fence), fence->ops->get_timeline_name(fence), dma_fence_is_signaled(fence) ? "" : "un"); - for (i = 0; i < shared_count; i++) { + dma_fence_put(fence); + } + + rcu_read_lock(); + fobj = rcu_dereference(robj->fence); + shared_count = fobj ? fobj->shared_count : 0; + for (i = 0, fence = NULL; i < shared_count; i++) { fence = rcu_dereference(fobj->shared[i]); if (!dma_fence_get_rcu(fence)) continue; + rcu_read_unlock(); + seq_printf(s, "\tShared fence: %s %s %ssignalled\n", fence->ops->get_driver_name(fence), fence->ops->get_timeline_name(fence), dma_fence_is_signaled(fence) ? "" : "un"); + dma_fence_put(fence); + + rcu_read_lock(); + fobj = rcu_dereference(robj->fence); + shared_count = fobj ? fobj->shared_count : 0; } rcu_read_unlock(); -- 2.17.2 ___ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
Re: [PATCH] dma-buf: fix debugfs versus rcu and fence dumping
On Thu, Dec 06, 2018 at 08:09:28AM +, Koenig, Christian wrote: > Am 06.12.18 um 02:41 schrieb jgli...@redhat.com: > > From: Jérôme Glisse > > > > The debugfs take reference on fence without dropping them. Also the > > rcu section are not well balance. Fix all that ... > > > > Signed-off-by: Jérôme Glisse > > Cc: Christian König > > Cc: Daniel Vetter > > Cc: Sumit Semwal > > Cc: linux-me...@vger.kernel.org > > Cc: dri-devel@lists.freedesktop.org > > Cc: linaro-mm-...@lists.linaro.org > > Cc: Stéphane Marchesin > > Cc: sta...@vger.kernel.org > > Well NAK, you are now taking the RCU lock twice and dropping the RCU and > still accessing fobj has a huge potential for accessing freed up memory. > > The only correct thing I can see here is to grab a reference to the > fence before printing any info on it, > Christian. Hu ? That is exactly what i am doing, take reference under rcu, rcu_unlock print the fence info, drop the fence reference, rcu lock rinse and repeat ... Note that the fobj in _existing_ code is access outside the rcu end that there is an rcu imbalance in that code ie a lonlely rcu_unlock after the for loop. So that the existing code is broken. > > > --- > > drivers/dma-buf/dma-buf.c | 11 +-- > > 1 file changed, 9 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c > > index 13884474d158..f6f4de42ac49 100644 > > --- a/drivers/dma-buf/dma-buf.c > > +++ b/drivers/dma-buf/dma-buf.c > > @@ -1051,24 +1051,31 @@ static int dma_buf_debug_show(struct seq_file *s, > > void *unused) > > fobj = rcu_dereference(robj->fence); > > shared_count = fobj ? fobj->shared_count : 0; > > fence = rcu_dereference(robj->fence_excl); > > + fence = dma_fence_get_rcu(fence); > > if (!read_seqcount_retry(&robj->seq, seq)) > > break; > > rcu_read_unlock(); > > } > > - > > - if (fence) > > + if (fence) { > > seq_printf(s, "\tExclusive fence: %s %s %ssignalled\n", > >fence->ops->get_driver_name(fence), > >fence->ops->get_timeline_name(fence), > >dma_fence_is_signaled(fence) ? "" : "un"); > > + dma_fence_put(fence); > > + } > > + > > + rcu_read_lock(); > > for (i = 0; i < shared_count; i++) { > > fence = rcu_dereference(fobj->shared[i]); > > if (!dma_fence_get_rcu(fence)) > > continue; > > + rcu_read_unlock(); > > seq_printf(s, "\tShared fence: %s %s %ssignalled\n", > >fence->ops->get_driver_name(fence), > >fence->ops->get_timeline_name(fence), > >dma_fence_is_signaled(fence) ? "" : "un"); > > + dma_fence_put(fence); > > + rcu_read_lock(); > > } > > rcu_read_unlock(); > > > ___ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
Re: [PATCH] dma-buf: fix debugfs versus rcu and fence dumping
Am 06.12.18 um 02:41 schrieb jgli...@redhat.com: > From: Jérôme Glisse > > The debugfs take reference on fence without dropping them. Also the > rcu section are not well balance. Fix all that ... > > Signed-off-by: Jérôme Glisse > Cc: Christian König > Cc: Daniel Vetter > Cc: Sumit Semwal > Cc: linux-me...@vger.kernel.org > Cc: dri-devel@lists.freedesktop.org > Cc: linaro-mm-...@lists.linaro.org > Cc: Stéphane Marchesin > Cc: sta...@vger.kernel.org Well NAK, you are now taking the RCU lock twice and dropping the RCU and still accessing fobj has a huge potential for accessing freed up memory. The only correct thing I can see here is to grab a reference to the fence before printing any info on it, Christian. > --- > drivers/dma-buf/dma-buf.c | 11 +-- > 1 file changed, 9 insertions(+), 2 deletions(-) > > diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c > index 13884474d158..f6f4de42ac49 100644 > --- a/drivers/dma-buf/dma-buf.c > +++ b/drivers/dma-buf/dma-buf.c > @@ -1051,24 +1051,31 @@ static int dma_buf_debug_show(struct seq_file *s, > void *unused) > fobj = rcu_dereference(robj->fence); > shared_count = fobj ? fobj->shared_count : 0; > fence = rcu_dereference(robj->fence_excl); > + fence = dma_fence_get_rcu(fence); > if (!read_seqcount_retry(&robj->seq, seq)) > break; > rcu_read_unlock(); > } > - > - if (fence) > + if (fence) { > seq_printf(s, "\tExclusive fence: %s %s %ssignalled\n", > fence->ops->get_driver_name(fence), > fence->ops->get_timeline_name(fence), > dma_fence_is_signaled(fence) ? "" : "un"); > + dma_fence_put(fence); > + } > + > + rcu_read_lock(); > for (i = 0; i < shared_count; i++) { > fence = rcu_dereference(fobj->shared[i]); > if (!dma_fence_get_rcu(fence)) > continue; > + rcu_read_unlock(); > seq_printf(s, "\tShared fence: %s %s %ssignalled\n", > fence->ops->get_driver_name(fence), > fence->ops->get_timeline_name(fence), > dma_fence_is_signaled(fence) ? "" : "un"); > + dma_fence_put(fence); > + rcu_read_lock(); > } > rcu_read_unlock(); > ___ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
[PATCH] dma-buf: fix debugfs versus rcu and fence dumping
From: Jérôme Glisse The debugfs take reference on fence without dropping them. Also the rcu section are not well balance. Fix all that ... Signed-off-by: Jérôme Glisse Cc: Christian König Cc: Daniel Vetter Cc: Sumit Semwal Cc: linux-me...@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linaro-mm-...@lists.linaro.org Cc: Stéphane Marchesin Cc: sta...@vger.kernel.org --- drivers/dma-buf/dma-buf.c | 11 +-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index 13884474d158..f6f4de42ac49 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -1051,24 +1051,31 @@ static int dma_buf_debug_show(struct seq_file *s, void *unused) fobj = rcu_dereference(robj->fence); shared_count = fobj ? fobj->shared_count : 0; fence = rcu_dereference(robj->fence_excl); + fence = dma_fence_get_rcu(fence); if (!read_seqcount_retry(&robj->seq, seq)) break; rcu_read_unlock(); } - - if (fence) + if (fence) { seq_printf(s, "\tExclusive fence: %s %s %ssignalled\n", fence->ops->get_driver_name(fence), fence->ops->get_timeline_name(fence), dma_fence_is_signaled(fence) ? "" : "un"); + dma_fence_put(fence); + } + + rcu_read_lock(); for (i = 0; i < shared_count; i++) { fence = rcu_dereference(fobj->shared[i]); if (!dma_fence_get_rcu(fence)) continue; + rcu_read_unlock(); seq_printf(s, "\tShared fence: %s %s %ssignalled\n", fence->ops->get_driver_name(fence), fence->ops->get_timeline_name(fence), dma_fence_is_signaled(fence) ? "" : "un"); + dma_fence_put(fence); + rcu_read_lock(); } rcu_read_unlock(); -- 2.17.2 ___ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel