| Message ID | 1383752507-25902-1-git-send-email-ricardo.ribalda@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi, On 06/11/13 16:41, Ricardo Ribalda Delgado wrote: > From: Ricardo Ribalda <ricardo.ribalda@gmail.com> > > vb2_fop_release does not held the lock although it is modifying the > queue->owner field. > > This could lead to race conditions on the vb2_perform_io function > when multiple applications are accessing the video device via > read/write API: [...] > > Acked-by: Hans Verkuil <hans.verkuil@cisco.com> > Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> Acked-by: Sylwester Nawrocki <s.nawrocki@samsung.com> Thanks for sticking with it and reworking it many times. Regards, Sylwester -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 11/06/2013 04:41 PM, Ricardo Ribalda Delgado wrote: > From: Ricardo Ribalda <ricardo.ribalda@gmail.com> > > vb2_fop_release does not held the lock although it is modifying the > queue->owner field. > > This could lead to race conditions on the vb2_perform_io function > when multiple applications are accessing the video device via > read/write API: > > [ 308.297741] BUG: unable to handle kernel NULL pointer dereference at > 0000000000000260 > [ 308.297759] IP: [<ffffffffa07a9fd2>] vb2_perform_fileio+0x372/0x610 > [videobuf2_core] > [ 308.297794] PGD 159719067 PUD 158119067 PMD 0 > [ 308.297812] Oops: 0000 #1 SMP > [ 308.297826] Modules linked in: qt5023_video videobuf2_dma_sg > qtec_xform videobuf2_vmalloc videobuf2_memops videobuf2_core > qtec_white qtec_mem gpio_xilinx qtec_cmosis qtec_pcie fglrx(PO) > spi_xilinx spi_bitbang qt5023 > [ 308.297888] CPU: 1 PID: 2189 Comm: java Tainted: P O 3.11.0-qtec-standard #1 > [ 308.297919] Hardware name: QTechnology QT5022/QT5022, BIOS > PM_2.1.0.309 X64 05/23/2013 > [ 308.297952] task: ffff8801564e1690 ti: ffff88014dc02000 task.ti: > ffff88014dc02000 > [ 308.297962] RIP: 0010:[<ffffffffa07a9fd2>] [<ffffffffa07a9fd2>] > vb2_perform_fileio+0x372/0x610 [videobuf2_core] > [ 308.297985] RSP: 0018:ffff88014dc03df8 EFLAGS: 00010202 > [ 308.297995] RAX: 0000000000000000 RBX: ffff880158a23000 RCX: dead000000100100 > [ 308.298003] RDX: 0000000000000000 RSI: dead000000200200 RDI: 0000000000000000 > [ 308.298012] RBP: ffff88014dc03e58 R08: 0000000000000000 R09: 0000000000000001 > [ 308.298020] R10: ffffea00051e8380 R11: ffff88014dc03fd8 R12: ffff880158a23070 > [ 308.298029] R13: ffff8801549040b8 R14: 0000000000198000 R15: 0000000001887e60 > [ 308.298040] FS: 00007f65130d5700(0000) GS:ffff88015ed00000(0000) > knlGS:0000000000000000 > [ 308.298049] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 308.298057] CR2: 0000000000000260 CR3: 0000000159630000 CR4: 00000000000007e0 > [ 308.298064] Stack: > [ 308.298071] ffff880156416c00 0000000000198000 0000000000000000 > ffff880100000001 > [ 308.298087] ffff88014dc03f50 00000000810a79ca 0002000000000001 > ffff880154904718 > [ 308.298101] ffff880156416c00 0000000000198000 ffff880154904338 > ffff88014dc03f50 > [ 308.298116] Call Trace: > [ 308.298143] [<ffffffffa07aa3c4>] vb2_read+0x14/0x20 [videobuf2_core] > [ 308.298198] [<ffffffffa07aa494>] vb2_fop_read+0xc4/0x120 [videobuf2_core] > [ 308.298252] [<ffffffff8154ee9e>] v4l2_read+0x7e/0xc0 > [ 308.298296] [<ffffffff8116e639>] vfs_read+0xa9/0x160 > [ 308.298312] [<ffffffff8116e882>] SyS_read+0x52/0xb0 > [ 308.298328] [<ffffffff81784179>] tracesys+0xd0/0xd5 > [ 308.298335] Code: e5 d6 ff ff 83 3d be 24 00 00 04 89 c2 4c 8b 45 b0 > 44 8b 4d b8 0f 8f 20 02 00 00 85 d2 75 32 83 83 78 03 00 00 01 4b 8b > 44 c5 48 <8b> 88 60 02 00 00 85 c9 0f 84 b0 00 00 00 8b 40 58 89 c2 41 > 89 > [ 308.298487] RIP [<ffffffffa07a9fd2>] vb2_perform_fileio+0x372/0x610 > [videobuf2_core] > [ 308.298507] RSP <ffff88014dc03df8> > [ 308.298514] CR2: 0000000000000260 > [ 308.298526] ---[ end trace e8f01717c96d1e41 ]--- > > Acked-by: Hans Verkuil <hans.verkuil@cisco.com> > Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> > --- > > v2: Comments by Sylvester Nawrocki > > fimc-capture and fimc-lite where calling vb2_fop_release with the lock held. > Therefore a new __vb2_fop_release function has been created to be used by > drivers that overload the release function. > > v3: Comments by Sylvester Nawrocki and Mauro Carvalho Chehab > > Use vb2_fop_release_locked instead of __vb2_fop_release > > v4: Comments by Sylvester Nawrocki > > Rename vb2_fop_release_locked to __vb2_fop_release and fix patch format > > v5: Comments by Sylvester Nawrocki and Hans Verkuil > > Rename __vb2_fop_release to vb2_fop_release_unlock and rearrange > arguments > > v6: Comments by Hans Verkuil > > Fix typo on description > Rename vb2_fop_release_locked to vb2_fop_release_no_lock > > v7: Comments by Hans Verkuil and Sylvester Nawrocki > > Export _vb2_fop_release instead of using vb2_fop_release_no_lock > > drivers/media/platform/exynos4-is/fimc-capture.c | 2 +- > drivers/media/platform/exynos4-is/fimc-lite.c | 2 +- > drivers/media/v4l2-core/videobuf2-core.c | 15 ++++++++++++++- > include/media/videobuf2-core.h | 1 + > 4 files changed, 17 insertions(+), 3 deletions(-) > > diff --git a/drivers/media/platform/exynos4-is/fimc-capture.c b/drivers/media/platform/exynos4-is/fimc-capture.c > index fb27ff7..8a712ca 100644 > --- a/drivers/media/platform/exynos4-is/fimc-capture.c > +++ b/drivers/media/platform/exynos4-is/fimc-capture.c > @@ -549,7 +549,7 @@ static int fimc_capture_release(struct file *file) > vc->streaming = false; > } > > - ret = vb2_fop_release(file); > + ret = _vb2_fop_release(file, NULL); > > if (close) { > clear_bit(ST_CAPT_BUSY, &fimc->state); > diff --git a/drivers/media/platform/exynos4-is/fimc-lite.c b/drivers/media/platform/exynos4-is/fimc-lite.c > index e5798f7..d3b32b6 100644 > --- a/drivers/media/platform/exynos4-is/fimc-lite.c > +++ b/drivers/media/platform/exynos4-is/fimc-lite.c > @@ -546,7 +546,7 @@ static int fimc_lite_release(struct file *file) > mutex_unlock(&entity->parent->graph_mutex); > } > > - vb2_fop_release(file); > + _vb2_fop_release(file, NULL); > pm_runtime_put(&fimc->pdev->dev); > clear_bit(ST_FLITE_SUSPENDED, &fimc->state); > > diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c > index 594c75e..52dbe2f 100644 > --- a/drivers/media/v4l2-core/videobuf2-core.c > +++ b/drivers/media/v4l2-core/videobuf2-core.c > @@ -2619,16 +2619,29 @@ int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma) > } > EXPORT_SYMBOL_GPL(vb2_fop_mmap); > > -int vb2_fop_release(struct file *file) > +int _vb2_fop_release(struct file *file, struct mutex *lock) > { > struct video_device *vdev = video_devdata(file); > > if (file->private_data == vdev->queue->owner) { > + if (lock) > + mutex_lock(lock); > vb2_queue_release(vdev->queue); > vdev->queue->owner = NULL; > + if (lock) > + mutex_unlock(lock); > } > return v4l2_fh_release(file); > } > +EXPORT_SYMBOL_GPL(_vb2_fop_release); > + > +int vb2_fop_release(struct file *file) > +{ > + struct video_device *vdev = video_devdata(file); > + struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock; > + > + return _vb2_fop_release(file, lock); > +} > EXPORT_SYMBOL_GPL(vb2_fop_release); > > ssize_t vb2_fop_write(struct file *file, char __user *buf, > diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h > index 6781258..5a9e239 100644 > --- a/include/media/videobuf2-core.h > +++ b/include/media/videobuf2-core.h > @@ -491,6 +491,7 @@ int vb2_ioctl_expbuf(struct file *file, void *priv, > > int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma); > int vb2_fop_release(struct file *file); > +int _vb2_fop_release(struct file *file, struct mutex *lock) Missing ';' at the end. Let me guess, you forgot to compile it :-) Regards, Hans > ssize_t vb2_fop_write(struct file *file, char __user *buf, > size_t count, loff_t *ppos); > ssize_t vb2_fop_read(struct file *file, char __user *buf, > -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/media/platform/exynos4-is/fimc-capture.c b/drivers/media/platform/exynos4-is/fimc-capture.c index fb27ff7..8a712ca 100644 --- a/drivers/media/platform/exynos4-is/fimc-capture.c +++ b/drivers/media/platform/exynos4-is/fimc-capture.c @@ -549,7 +549,7 @@ static int fimc_capture_release(struct file *file) vc->streaming = false; } - ret = vb2_fop_release(file); + ret = _vb2_fop_release(file, NULL); if (close) { clear_bit(ST_CAPT_BUSY, &fimc->state); diff --git a/drivers/media/platform/exynos4-is/fimc-lite.c b/drivers/media/platform/exynos4-is/fimc-lite.c index e5798f7..d3b32b6 100644 --- a/drivers/media/platform/exynos4-is/fimc-lite.c +++ b/drivers/media/platform/exynos4-is/fimc-lite.c @@ -546,7 +546,7 @@ static int fimc_lite_release(struct file *file) mutex_unlock(&entity->parent->graph_mutex); } - vb2_fop_release(file); + _vb2_fop_release(file, NULL); pm_runtime_put(&fimc->pdev->dev); clear_bit(ST_FLITE_SUSPENDED, &fimc->state); diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c index 594c75e..52dbe2f 100644 --- a/drivers/media/v4l2-core/videobuf2-core.c +++ b/drivers/media/v4l2-core/videobuf2-core.c @@ -2619,16 +2619,29 @@ int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma) } EXPORT_SYMBOL_GPL(vb2_fop_mmap); -int vb2_fop_release(struct file *file) +int _vb2_fop_release(struct file *file, struct mutex *lock) { struct video_device *vdev = video_devdata(file); if (file->private_data == vdev->queue->owner) { + if (lock) + mutex_lock(lock); vb2_queue_release(vdev->queue); vdev->queue->owner = NULL; + if (lock) + mutex_unlock(lock); } return v4l2_fh_release(file); } +EXPORT_SYMBOL_GPL(_vb2_fop_release); + +int vb2_fop_release(struct file *file) +{ + struct video_device *vdev = video_devdata(file); + struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock; + + return _vb2_fop_release(file, lock); +} EXPORT_SYMBOL_GPL(vb2_fop_release); ssize_t vb2_fop_write(struct file *file, char __user *buf, diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h index 6781258..5a9e239 100644 --- a/include/media/videobuf2-core.h +++ b/include/media/videobuf2-core.h @@ -491,6 +491,7 @@ int vb2_ioctl_expbuf(struct file *file, void *priv, int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma); int vb2_fop_release(struct file *file); +int _vb2_fop_release(struct file *file, struct mutex *lock) ssize_t vb2_fop_write(struct file *file, char __user *buf, size_t count, loff_t *ppos); ssize_t vb2_fop_read(struct file *file, char __user *buf,