From 511a1b8a4c816a4e46a0d0aea9221ff3c708282e Mon Sep 17 00:00:00 2001 From: Hans Verkuil Date: Mon, 15 Jun 2015 04:16:32 -0300 Subject: [media] Revert "[media] vb2: Push mmap_sem down to memops" This reverts commit 48b25a3a713b90988b6882d318f7c0a6bed9aabc. That commit caused two regressions. The first is a BUG: Jun 14 18:42:15 test-media kernel: [ 115.972299] BUG: unable to handle kernel NULL pointer dereference at 0000000000000100 Jun 14 18:42:15 test-media kernel: [ 115.972307] IP: [] __lock_acquire+0x2f0/0x2070 Jun 14 18:42:15 test-media kernel: [ 115.972316] PGD 0 Jun 14 18:42:15 test-media kernel: [ 115.972318] Oops: 0000 [#1] PREEMPT SMP Jun 14 18:42:15 test-media kernel: [ 115.972321] Modules linked in: vivid v4l2_dv_timings videobuf2_vmalloc videobuf2_memops videobuf2_core v4l2_common videodev media vmw_balloon vmw_vmci acpi_cpufreq processor button Jun 14 18:42:15 test-media kernel: [ 115.972333] CPU: 0 PID: 1542 Comm: v4l2-ctl Not tainted 4.1.0-rc3-test-media #1190 Jun 14 18:42:15 test-media kernel: [ 115.972336] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 05/20/2014 Jun 14 18:42:15 test-media kernel: [ 115.972337] task: ffff880220ce4200 ti: ffff88021d16c000 task.ti: ffff88021d16c000 Jun 14 18:42:15 test-media kernel: [ 115.972339] RIP: 0010:[] [] __lock_acquire+0x2f0/0x2070 Jun 14 18:42:15 test-media kernel: [ 115.972342] RSP: 0018:ffff88021d16f9b8 EFLAGS: 00010002 Jun 14 18:42:15 test-media kernel: [ 115.972343] RAX: 0000000000000046 RBX: 0000000000000292 RCX: 0000000000000001 Jun 14 18:42:15 test-media kernel: [ 115.972345] RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000100 Jun 14 18:42:15 test-media kernel: [ 115.972346] RBP: ffff88021d16fa88 R08: 0000000000000001 R09: 0000000000000000 Jun 14 18:42:15 test-media kernel: [ 115.972347] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000001 Jun 14 18:42:15 test-media kernel: [ 115.972348] R13: ffff880220ce4200 R14: 0000000000000100 R15: 0000000000000000 Jun 14 18:42:15 test-media kernel: [ 115.972350] FS: 00007f2441e7f740(0000) GS:ffff880236e00000(0000) knlGS:0000000000000000 Jun 14 18:42:15 test-media kernel: [ 115.972351] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b Jun 14 18:42:15 test-media kernel: [ 115.972353] CR2: 0000000000000100 CR3: 0000000001e0b000 CR4: 00000000001406f0 Jun 14 18:42:15 test-media kernel: [ 115.972424] Stack: Jun 14 18:42:15 test-media kernel: [ 115.972427] ffff88021d16fa98 ffffffff810d6543 0000000000000006 0000000000000246 Jun 14 18:42:15 test-media kernel: [ 115.972431] ffff88021d16fa08 ffffffff810d532d ffff880220ce4a78 ffff880200000000 Jun 14 18:42:15 test-media kernel: [ 115.972433] ffff880200000001 0000000000000000 0000000000000001 000000000093a4a0 Jun 14 18:42:15 test-media kernel: [ 115.972436] Call Trace: Jun 14 18:42:15 test-media kernel: [ 115.972440] [] ? __lock_acquire+0xb63/0x2070 Jun 14 18:42:15 test-media kernel: [ 115.972443] [] ? mark_held_locks+0x6d/0xa0 Jun 14 18:42:15 test-media kernel: [ 115.972445] [] ? __lock_is_held+0x58/0x80 Jun 14 18:42:15 test-media kernel: [ 115.972447] [] lock_acquire+0x6c/0xa0 Jun 14 18:42:15 test-media kernel: [ 115.972452] [] ? vb2_vmalloc_put_userptr+0x36/0x110 [videobuf2_vmalloc] Jun 14 18:42:15 test-media kernel: [ 115.972458] [] down_read+0x42/0x60 Jun 14 18:42:15 test-media kernel: [ 115.972460] [] ? vb2_vmalloc_put_userptr+0x36/0x110 [videobuf2_vmalloc] Jun 14 18:42:15 test-media kernel: [ 115.972463] [] ? mutex_lock_nested+0x2b1/0x560 Jun 14 18:42:15 test-media kernel: [ 115.972467] [] ? vb2_queue_release+0x25/0x40 [videobuf2_core] Jun 14 18:42:15 test-media kernel: [ 115.972469] [] vb2_vmalloc_put_userptr+0x36/0x110 [videobuf2_vmalloc] Jun 14 18:42:15 test-media kernel: [ 115.972472] [] __vb2_queue_free+0x146/0x5e0 [videobuf2_core] Jun 14 18:42:15 test-media kernel: [ 115.972475] [] vb2_queue_release+0x33/0x40 [videobuf2_core] Jun 14 18:42:15 test-media kernel: [ 115.972478] [] _vb2_fop_release+0x95/0xb0 [videobuf2_core] Jun 14 18:42:15 test-media kernel: [ 115.972481] [] vb2_fop_release+0x29/0x50 [videobuf2_core] Jun 14 18:42:15 test-media kernel: [ 115.972485] [] vivid_fop_release+0x92/0x230 [vivid] Jun 14 18:42:15 test-media kernel: [ 115.972491] [] v4l2_release+0x30/0x80 [videodev] Jun 14 18:42:15 test-media kernel: [ 115.972496] [] __fput+0xe5/0x200 Jun 14 18:42:15 test-media kernel: [ 115.972498] [] ____fput+0x9/0x10 Jun 14 18:42:15 test-media kernel: [ 115.972501] [] task_work_run+0xc4/0xf0 Jun 14 18:42:15 test-media kernel: [ 115.972504] [] do_exit+0x3a0/0xaf0 Jun 14 18:42:15 test-media kernel: [ 115.972507] [] ? _raw_spin_unlock_irq+0x2b/0x60 Jun 14 18:42:15 test-media kernel: [ 115.972509] [] do_group_exit+0x4f/0xe0 Jun 14 18:42:15 test-media kernel: [ 115.972511] [] get_signal+0x200/0x8c0 Jun 14 18:42:15 test-media kernel: [ 115.972514] [] ? __mutex_unlock_slowpath+0xf5/0x240 Jun 14 18:42:15 test-media kernel: [ 115.972518] [] do_signal+0x23/0x820 Jun 14 18:42:15 test-media kernel: [ 115.972521] [] ? mutex_unlock+0x9/0x10 Jun 14 18:42:15 test-media kernel: [ 115.972524] [] ? v4l2_ioctl+0x78/0xf0 [videodev] Jun 14 18:42:15 test-media kernel: [ 115.972526] [] ? int_very_careful+0x5/0x46 Jun 14 18:42:15 test-media kernel: [ 115.972529] [] ? trace_hardirqs_on_caller+0x15d/0x200 Jun 14 18:42:15 test-media kernel: [ 115.972531] [] do_notify_resume+0x50/0x60 Jun 14 18:42:15 test-media kernel: [ 115.972533] [] int_signal+0x12/0x17 Jun 14 18:42:15 test-media kernel: [ 115.972534] Code: ca 81 31 c0 e8 7a e2 8c 00 e8 aa 1d 8d 00 0f 1f 44 00 00 31 db 48 81 c4 a8 00 00 00 89 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 66 90 <49> 81 3e 40 4e 02 82 b8 00 00 00 00 44 0f 44 e0 41 83 ff 01 0f Jun 14 18:42:15 test-media kernel: [ 115.972567] RIP [] __lock_acquire+0x2f0/0x2070 Jun 14 18:42:15 test-media kernel: [ 115.972569] RSP Jun 14 18:42:15 test-media kernel: [ 115.972570] CR2: 0000000000000100 Jun 14 18:42:15 test-media kernel: [ 115.972573] ---[ end trace 25595c2b8560cb57 ]--- Jun 14 18:42:15 test-media kernel: [ 115.972575] Fixing recursive fault but reboot is needed! This can be reproduced by loading the vivid driver and running: v4l2-ctl --stream-user and pressing Ctrl-C. You may have to try a few times, but in my experience this BUG is triggered quite quickly. The second is a possible deadlock: Jun 14 18:44:07 test-media kernel: [ 49.376650] ====================================================== Jun 14 18:44:07 test-media kernel: [ 49.376651] [ INFO: possible circular locking dependency detected ] Jun 14 18:44:07 test-media kernel: [ 49.376653] 4.1.0-rc3-test-media #1190 Not tainted Jun 14 18:44:07 test-media kernel: [ 49.376654] ------------------------------------------------------- Jun 14 18:44:07 test-media kernel: [ 49.376655] v4l2-compliance/1468 is trying to acquire lock: Jun 14 18:44:07 test-media kernel: [ 49.376657] (&mm->mmap_sem){++++++}, at: [] vb2_vmalloc_put_userptr+0x36/0x110 [videobuf2_vmalloc] Jun 14 18:44:07 test-media kernel: [ 49.376665] Jun 14 18:44:07 test-media kernel: [ 49.376665] but task is already holding lock: Jun 14 18:44:07 test-media kernel: [ 49.376666] (&q->mmap_lock){+.+...}, at: [] vb2_queue_release+0x25/0x40 [videobuf2_core] Jun 14 18:44:07 test-media kernel: [ 49.376670] Jun 14 18:44:07 test-media kernel: [ 49.376670] which lock already depends on the new lock. Jun 14 18:44:07 test-media kernel: [ 49.376670] Jun 14 18:44:07 test-media kernel: [ 49.376671] Jun 14 18:44:07 test-media kernel: [ 49.376671] the existing dependency chain (in reverse order) is: Jun 14 18:44:07 test-media kernel: [ 49.376672] Jun 14 18:44:07 test-media kernel: [ 49.376672] -> #1 (&q->mmap_lock){+.+...}: Jun 14 18:44:07 test-media kernel: [ 49.376675] [] lock_acquire+0x6c/0xa0 Jun 14 18:44:07 test-media kernel: [ 49.376682] [] mutex_lock_nested+0x5e/0x560 Jun 14 18:44:07 test-media kernel: [ 49.376689] [] vb2_mmap+0x232/0x350 [videobuf2_core] Jun 14 18:44:07 test-media kernel: [ 49.376691] [] vb2_fop_mmap+0x20/0x30 [videobuf2_core] Jun 14 18:44:07 test-media kernel: [ 49.376694] [] v4l2_mmap+0x52/0x90 [videodev] Jun 14 18:44:07 test-media kernel: [ 49.376698] [] mmap_region+0x3b3/0x5e0 Jun 14 18:44:07 test-media kernel: [ 49.376701] [] do_mmap_pgoff+0x317/0x400 Jun 14 18:44:07 test-media kernel: [ 49.376703] [] vm_mmap_pgoff+0x90/0xc0 Jun 14 18:44:07 test-media kernel: [ 49.376708] [] SyS_mmap_pgoff+0x1d7/0x280 Jun 14 18:44:07 test-media kernel: [ 49.376709] [] SyS_mmap+0x1d/0x20 Jun 14 18:44:07 test-media kernel: [ 49.376714] [] system_call_fastpath+0x12/0x76 Jun 14 18:44:07 test-media kernel: [ 49.376716] Jun 14 18:44:07 test-media kernel: [ 49.376716] -> #0 (&mm->mmap_sem){++++++}: Jun 14 18:44:07 test-media kernel: [ 49.376718] [] __lock_acquire+0x1fd3/0x2070 Jun 14 18:44:07 test-media kernel: [ 49.376720] [] lock_acquire+0x6c/0xa0 Jun 14 18:44:07 test-media kernel: [ 49.376721] [] down_read+0x42/0x60 Jun 14 18:44:07 test-media kernel: [ 49.376723] [] vb2_vmalloc_put_userptr+0x36/0x110 [videobuf2_vmalloc] Jun 14 18:44:07 test-media kernel: [ 49.376725] [] __vb2_queue_free+0x146/0x5e0 [videobuf2_core] Jun 14 18:44:07 test-media kernel: [ 49.376727] [] vb2_queue_release+0x33/0x40 [videobuf2_core] Jun 14 18:44:07 test-media kernel: [ 49.376729] [] _vb2_fop_release+0x95/0xb0 [videobuf2_core] Jun 14 18:44:07 test-media kernel: [ 49.376731] [] vb2_fop_release+0x29/0x50 [videobuf2_core] Jun 14 18:44:07 test-media kernel: [ 49.376733] [] vivid_fop_release+0x92/0x230 [vivid] Jun 14 18:44:07 test-media kernel: [ 49.376737] [] v4l2_release+0x30/0x80 [videodev] Jun 14 18:44:07 test-media kernel: [ 49.376739] [] __fput+0xe5/0x200 Jun 14 18:44:07 test-media kernel: [ 49.376744] [] ____fput+0x9/0x10 Jun 14 18:44:07 test-media kernel: [ 49.376746] [] task_work_run+0xc4/0xf0 Jun 14 18:44:07 test-media kernel: [ 49.376749] [] do_notify_resume+0x41/0x60 Jun 14 18:44:07 test-media kernel: [ 49.376752] [] int_signal+0x12/0x17 Jun 14 18:44:07 test-media kernel: [ 49.376754] Jun 14 18:44:07 test-media kernel: [ 49.376754] other info that might help us debug this: Jun 14 18:44:07 test-media kernel: [ 49.376754] Jun 14 18:44:07 test-media kernel: [ 49.376755] Possible unsafe locking scenario: Jun 14 18:44:07 test-media kernel: [ 49.376755] Jun 14 18:44:07 test-media kernel: [ 49.376756] CPU0 CPU1 Jun 14 18:44:07 test-media kernel: [ 49.376757] ---- ---- Jun 14 18:44:07 test-media kernel: [ 49.376758] lock(&q->mmap_lock); Jun 14 18:44:07 test-media kernel: [ 49.376759] lock(&mm->mmap_sem); Jun 14 18:44:07 test-media kernel: [ 49.376760] lock(&q->mmap_lock); Jun 14 18:44:07 test-media kernel: [ 49.376761] lock(&mm->mmap_sem); Jun 14 18:44:07 test-media kernel: [ 49.376763] Jun 14 18:44:07 test-media kernel: [ 49.376763] *** DEADLOCK *** Jun 14 18:44:07 test-media kernel: [ 49.376763] Jun 14 18:44:07 test-media kernel: [ 49.376764] 2 locks held by v4l2-compliance/1468: Jun 14 18:44:07 test-media kernel: [ 49.376765] #0: (&dev->mutex#3){+.+.+.}, at: [] _vb2_fop_release+0x2a/0xb0 [videobuf2_core] Jun 14 18:44:07 test-media kernel: [ 49.376770] #1: (&q->mmap_lock){+.+...}, at: [] vb2_queue_release+0x25/0x40 [videobuf2_core] Jun 14 18:44:07 test-media kernel: [ 49.376773] Jun 14 18:44:07 test-media kernel: [ 49.376773] stack backtrace: Jun 14 18:44:07 test-media kernel: [ 49.376776] CPU: 2 PID: 1468 Comm: v4l2-compliance Not tainted 4.1.0-rc3-test-media #1190 Jun 14 18:44:07 test-media kernel: [ 49.376777] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 05/20/2014 Jun 14 18:44:07 test-media kernel: [ 49.376779] ffffffff8279e0b0 ffff88021d6f7ba8 ffffffff819a7aac 0000000000000011 Jun 14 18:44:07 test-media kernel: [ 49.376781] ffffffff8279e0b0 ffff88021d6f7bf8 ffffffff819a3964 ffff88021d6f7bd8 Jun 14 18:44:07 test-media kernel: [ 49.376783] ffff8800ac8aa100 0000000000000002 ffff8800ac8aa9a0 0000000000000002 Jun 14 18:44:07 test-media kernel: [ 49.376785] Call Trace: Jun 14 18:44:07 test-media kernel: [ 49.376788] [] dump_stack+0x4f/0x7b Jun 14 18:44:07 test-media kernel: [ 49.376792] [] print_circular_bug+0x20f/0x251 Jun 14 18:44:07 test-media kernel: [ 49.376793] [] __lock_acquire+0x1fd3/0x2070 Jun 14 18:44:07 test-media kernel: [ 49.376795] [] ? __lock_acquire+0xb63/0x2070 Jun 14 18:44:07 test-media kernel: [ 49.376797] [] ? __lock_is_held+0x58/0x80 Jun 14 18:44:07 test-media kernel: [ 49.376798] [] lock_acquire+0x6c/0xa0 Jun 14 18:44:07 test-media kernel: [ 49.376800] [] ? vb2_vmalloc_put_userptr+0x36/0x110 [videobuf2_vmalloc] Jun 14 18:44:07 test-media kernel: [ 49.376802] [] down_read+0x42/0x60 Jun 14 18:44:07 test-media kernel: [ 49.376803] [] ? vb2_vmalloc_put_userptr+0x36/0x110 [videobuf2_vmalloc] Jun 14 18:44:07 test-media kernel: [ 49.376805] [] ? mutex_lock_nested+0x2b1/0x560 Jun 14 18:44:07 test-media kernel: [ 49.376807] [] ? vb2_queue_release+0x25/0x40 [videobuf2_core] Jun 14 18:44:07 test-media kernel: [ 49.376808] [] vb2_vmalloc_put_userptr+0x36/0x110 [videobuf2_vmalloc] Jun 14 18:44:07 test-media kernel: [ 49.376810] [] ? _vb2_fop_release+0x2a/0xb0 [videobuf2_core] Jun 14 18:44:07 test-media kernel: [ 49.376812] [] __vb2_queue_free+0x146/0x5e0 [videobuf2_core] Jun 14 18:44:07 test-media kernel: [ 49.376814] [] vb2_queue_release+0x33/0x40 [videobuf2_core] Jun 14 18:44:07 test-media kernel: [ 49.376816] [] _vb2_fop_release+0x95/0xb0 [videobuf2_core] Jun 14 18:44:07 test-media kernel: [ 49.376818] [] vb2_fop_release+0x29/0x50 [videobuf2_core] Jun 14 18:44:07 test-media kernel: [ 49.376820] [] vivid_fop_release+0x92/0x230 [vivid] Jun 14 18:44:07 test-media kernel: [ 49.376822] [] v4l2_release+0x30/0x80 [videodev] Jun 14 18:44:07 test-media kernel: [ 49.376824] [] __fput+0xe5/0x200 Jun 14 18:44:07 test-media kernel: [ 49.376825] [] ? int_very_careful+0x5/0x46 Jun 14 18:44:07 test-media kernel: [ 49.376827] [] ____fput+0x9/0x10 Jun 14 18:44:07 test-media kernel: [ 49.376828] [] task_work_run+0xc4/0xf0 Jun 14 18:44:07 test-media kernel: [ 49.376830] [] do_notify_resume+0x41/0x60 Jun 14 18:44:07 test-media kernel: [ 49.376832] [] int_signal+0x12/0x17 This can be triggered by loading the vivid module with the module option 'no_error_inj=1' and running 'v4l2-compliance -s5'. Again, it may take a few attempts to trigger this but for me it happens quite quickly. Without this patch I cannot reproduce these two issues. So reverting is the best solution for now. Signed-off-by: Hans Verkuil Cc: Jan Kara Cc: Andrew Morton Signed-off-by: Mauro Carvalho Chehab --- drivers/media/v4l2-core/videobuf2-core.c | 2 ++ drivers/media/v4l2-core/videobuf2-dma-contig.c | 7 ------- drivers/media/v4l2-core/videobuf2-dma-sg.c | 6 ------ drivers/media/v4l2-core/videobuf2-vmalloc.c | 6 +----- 4 files changed, 3 insertions(+), 18 deletions(-) (limited to 'drivers/media') diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c index 1a096a62ef30..d835814a24d4 100644 --- a/drivers/media/v4l2-core/videobuf2-core.c +++ b/drivers/media/v4l2-core/videobuf2-core.c @@ -1662,7 +1662,9 @@ static int __buf_prepare(struct vb2_buffer *vb, const struct v4l2_buffer *b) ret = __qbuf_mmap(vb, b); break; case V4L2_MEMORY_USERPTR: + down_read(¤t->mm->mmap_sem); ret = __qbuf_userptr(vb, b); + up_read(¤t->mm->mmap_sem); break; case V4L2_MEMORY_DMABUF: ret = __qbuf_dmabuf(vb, b); diff --git a/drivers/media/v4l2-core/videobuf2-dma-contig.c b/drivers/media/v4l2-core/videobuf2-dma-contig.c index 369df95af5c7..94c1e6455d36 100644 --- a/drivers/media/v4l2-core/videobuf2-dma-contig.c +++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c @@ -532,9 +532,7 @@ static void vb2_dc_put_userptr(void *buf_priv) sg_free_table(sgt); kfree(sgt); } - down_read(¤t->mm->mmap_sem); vb2_put_vma(buf->vma); - up_read(¤t->mm->mmap_sem); kfree(buf); } @@ -618,7 +616,6 @@ static void *vb2_dc_get_userptr(void *alloc_ctx, unsigned long vaddr, goto fail_buf; } - down_read(¤t->mm->mmap_sem); /* current->mm->mmap_sem is taken by videobuf2 core */ vma = find_vma(current->mm, vaddr); if (!vma) { @@ -645,7 +642,6 @@ static void *vb2_dc_get_userptr(void *alloc_ctx, unsigned long vaddr, if (ret) { unsigned long pfn; if (vb2_dc_get_user_pfn(start, n_pages, vma, &pfn) == 0) { - up_read(¤t->mm->mmap_sem); buf->dma_addr = vb2_dc_pfn_to_dma(buf->dev, pfn); buf->size = size; kfree(pages); @@ -655,7 +651,6 @@ static void *vb2_dc_get_userptr(void *alloc_ctx, unsigned long vaddr, pr_err("failed to get user pages\n"); goto fail_vma; } - up_read(¤t->mm->mmap_sem); sgt = kzalloc(sizeof(*sgt), GFP_KERNEL); if (!sgt) { @@ -718,12 +713,10 @@ fail_get_user_pages: while (n_pages) put_page(pages[--n_pages]); - down_read(¤t->mm->mmap_sem); fail_vma: vb2_put_vma(buf->vma); fail_pages: - up_read(¤t->mm->mmap_sem); kfree(pages); /* kfree is NULL-proof */ fail_buf: diff --git a/drivers/media/v4l2-core/videobuf2-dma-sg.c b/drivers/media/v4l2-core/videobuf2-dma-sg.c index d7bcb05c7058..7289b81bd7b7 100644 --- a/drivers/media/v4l2-core/videobuf2-dma-sg.c +++ b/drivers/media/v4l2-core/videobuf2-dma-sg.c @@ -264,7 +264,6 @@ static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr, if (!buf->pages) goto userptr_fail_alloc_pages; - down_read(¤t->mm->mmap_sem); vma = find_vma(current->mm, vaddr); if (!vma) { dprintk(1, "no vma for address %lu\n", vaddr); @@ -303,7 +302,6 @@ static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr, 1, /* force */ buf->pages, NULL); - up_read(¤t->mm->mmap_sem); if (num_pages_from_user != buf->num_pages) goto userptr_fail_get_user_pages; @@ -333,10 +331,8 @@ userptr_fail_get_user_pages: if (!vma_is_io(buf->vma)) while (--num_pages_from_user >= 0) put_page(buf->pages[num_pages_from_user]); - down_read(¤t->mm->mmap_sem); vb2_put_vma(buf->vma); userptr_fail_find_vma: - up_read(¤t->mm->mmap_sem); kfree(buf->pages); userptr_fail_alloc_pages: kfree(buf); @@ -370,9 +366,7 @@ static void vb2_dma_sg_put_userptr(void *buf_priv) put_page(buf->pages[i]); } kfree(buf->pages); - down_read(¤t->mm->mmap_sem); vb2_put_vma(buf->vma); - up_read(¤t->mm->mmap_sem); kfree(buf); } diff --git a/drivers/media/v4l2-core/videobuf2-vmalloc.c b/drivers/media/v4l2-core/videobuf2-vmalloc.c index f6656fefc035..2fe4c27f524a 100644 --- a/drivers/media/v4l2-core/videobuf2-vmalloc.c +++ b/drivers/media/v4l2-core/videobuf2-vmalloc.c @@ -89,7 +89,7 @@ static void *vb2_vmalloc_get_userptr(void *alloc_ctx, unsigned long vaddr, offset = vaddr & ~PAGE_MASK; buf->size = size; - down_read(¤t->mm->mmap_sem); + vma = find_vma(current->mm, vaddr); if (vma && (vma->vm_flags & VM_PFNMAP) && (vma->vm_pgoff)) { if (vb2_get_contig_userptr(vaddr, size, &vma, &physp)) @@ -121,7 +121,6 @@ static void *vb2_vmalloc_get_userptr(void *alloc_ctx, unsigned long vaddr, if (!buf->vaddr) goto fail_get_user_pages; } - up_read(¤t->mm->mmap_sem); buf->vaddr += offset; return buf; @@ -134,7 +133,6 @@ fail_get_user_pages: kfree(buf->pages); fail_pages_array_alloc: - up_read(¤t->mm->mmap_sem); kfree(buf); return NULL; @@ -146,7 +144,6 @@ static void vb2_vmalloc_put_userptr(void *buf_priv) unsigned long vaddr = (unsigned long)buf->vaddr & PAGE_MASK; unsigned int i; - down_read(¤t->mm->mmap_sem); if (buf->pages) { if (vaddr) vm_unmap_ram((void *)vaddr, buf->n_pages); @@ -160,7 +157,6 @@ static void vb2_vmalloc_put_userptr(void *buf_priv) vb2_put_vma(buf->vma); iounmap((__force void __iomem *)buf->vaddr); } - up_read(¤t->mm->mmap_sem); kfree(buf); } -- cgit v1.2.3