aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/media/v4l2-core/videobuf2-vmalloc.c
diff options
context:
space:
mode:
authorHans Verkuil <hans.verkuil@cisco.com>2015-06-15 04:16:32 -0300
committerMauro Carvalho Chehab <mchehab@osg.samsung.com>2015-06-18 14:34:22 -0300
commit511a1b8a4c816a4e46a0d0aea9221ff3c708282e (patch)
treed4c795862d9725ff1c6bbf9337eee9bda6932547 /drivers/media/v4l2-core/videobuf2-vmalloc.c
parent6fe2d69c07864eecf33373b0e4be401737e37fa4 (diff)
[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: [<ffffffff810d5cd0>] __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:[<ffffffff810d5cd0>] [<ffffffff810d5cd0>] __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] [<ffffffff810d6543>] ? __lock_acquire+0xb63/0x2070 Jun 14 18:42:15 test-media kernel: [ 115.972443] [<ffffffff810d532d>] ? mark_held_locks+0x6d/0xa0 Jun 14 18:42:15 test-media kernel: [ 115.972445] [<ffffffff810d37a8>] ? __lock_is_held+0x58/0x80 Jun 14 18:42:15 test-media kernel: [ 115.972447] [<ffffffff810d852c>] lock_acquire+0x6c/0xa0 Jun 14 18:42:15 test-media kernel: [ 115.972452] [<ffffffffa039f1f6>] ? vb2_vmalloc_put_userptr+0x36/0x110 [videobuf2_vmalloc] Jun 14 18:42:15 test-media kernel: [ 115.972458] [<ffffffff819b1a92>] down_read+0x42/0x60 Jun 14 18:42:15 test-media kernel: [ 115.972460] [<ffffffffa039f1f6>] ? vb2_vmalloc_put_userptr+0x36/0x110 [videobuf2_vmalloc] Jun 14 18:42:15 test-media kernel: [ 115.972463] [<ffffffff819af1b1>] ? mutex_lock_nested+0x2b1/0x560 Jun 14 18:42:15 test-media kernel: [ 115.972467] [<ffffffffa038fdc5>] ? vb2_queue_release+0x25/0x40 [videobuf2_core] Jun 14 18:42:15 test-media kernel: [ 115.972469] [<ffffffffa039f1f6>] vb2_vmalloc_put_userptr+0x36/0x110 [videobuf2_vmalloc] Jun 14 18:42:15 test-media kernel: [ 115.972472] [<ffffffffa038b626>] __vb2_queue_free+0x146/0x5e0 [videobuf2_core] Jun 14 18:42:15 test-media kernel: [ 115.972475] [<ffffffffa038fdd3>] vb2_queue_release+0x33/0x40 [videobuf2_core] Jun 14 18:42:15 test-media kernel: [ 115.972478] [<ffffffffa038fe75>] _vb2_fop_release+0x95/0xb0 [videobuf2_core] Jun 14 18:42:15 test-media kernel: [ 115.972481] [<ffffffffa038feb9>] vb2_fop_release+0x29/0x50 [videobuf2_core] Jun 14 18:42:15 test-media kernel: [ 115.972485] [<ffffffffa03ad372>] vivid_fop_release+0x92/0x230 [vivid] Jun 14 18:42:15 test-media kernel: [ 115.972491] [<ffffffffa0358460>] v4l2_release+0x30/0x80 [videodev] Jun 14 18:42:15 test-media kernel: [ 115.972496] [<ffffffff811a51d5>] __fput+0xe5/0x200 Jun 14 18:42:15 test-media kernel: [ 115.972498] [<ffffffff811a5339>] ____fput+0x9/0x10 Jun 14 18:42:15 test-media kernel: [ 115.972501] [<ffffffff810a9fa4>] task_work_run+0xc4/0xf0 Jun 14 18:42:15 test-media kernel: [ 115.972504] [<ffffffff8108c670>] do_exit+0x3a0/0xaf0 Jun 14 18:42:15 test-media kernel: [ 115.972507] [<ffffffff819b3a9b>] ? _raw_spin_unlock_irq+0x2b/0x60 Jun 14 18:42:15 test-media kernel: [ 115.972509] [<ffffffff8108e0ff>] do_group_exit+0x4f/0xe0 Jun 14 18:42:15 test-media kernel: [ 115.972511] [<ffffffff8109a170>] get_signal+0x200/0x8c0 Jun 14 18:42:15 test-media kernel: [ 115.972514] [<ffffffff819b14b5>] ? __mutex_unlock_slowpath+0xf5/0x240 Jun 14 18:42:15 test-media kernel: [ 115.972518] [<ffffffff81002593>] do_signal+0x23/0x820 Jun 14 18:42:15 test-media kernel: [ 115.972521] [<ffffffff819b1609>] ? mutex_unlock+0x9/0x10 Jun 14 18:42:15 test-media kernel: [ 115.972524] [<ffffffffa0358648>] ? v4l2_ioctl+0x78/0xf0 [videodev] Jun 14 18:42:15 test-media kernel: [ 115.972526] [<ffffffff819b4653>] ? int_very_careful+0x5/0x46 Jun 14 18:42:15 test-media kernel: [ 115.972529] [<ffffffff810d54bd>] ? trace_hardirqs_on_caller+0x15d/0x200 Jun 14 18:42:15 test-media kernel: [ 115.972531] [<ffffffff81002de0>] do_notify_resume+0x50/0x60 Jun 14 18:42:15 test-media kernel: [ 115.972533] [<ffffffff819b46a6>] 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 [<ffffffff810d5cd0>] __lock_acquire+0x2f0/0x2070 Jun 14 18:42:15 test-media kernel: [ 115.972569] RSP <ffff88021d16f9b8> 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: [<ffffffffa03a81f6>] 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: [<ffffffffa0398dc5>] 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] [<ffffffff810d852c>] lock_acquire+0x6c/0xa0 Jun 14 18:44:07 test-media kernel: [ 49.376682] [<ffffffff819aef5e>] mutex_lock_nested+0x5e/0x560 Jun 14 18:44:07 test-media kernel: [ 49.376689] [<ffffffffa03934a2>] vb2_mmap+0x232/0x350 [videobuf2_core] Jun 14 18:44:07 test-media kernel: [ 49.376691] [<ffffffffa0395a60>] vb2_fop_mmap+0x20/0x30 [videobuf2_core] Jun 14 18:44:07 test-media kernel: [ 49.376694] [<ffffffffa0361102>] v4l2_mmap+0x52/0x90 [videodev] Jun 14 18:44:07 test-media kernel: [ 49.376698] [<ffffffff81177e33>] mmap_region+0x3b3/0x5e0 Jun 14 18:44:07 test-media kernel: [ 49.376701] [<ffffffff81178377>] do_mmap_pgoff+0x317/0x400 Jun 14 18:44:07 test-media kernel: [ 49.376703] [<ffffffff81165320>] vm_mmap_pgoff+0x90/0xc0 Jun 14 18:44:07 test-media kernel: [ 49.376708] [<ffffffff81176867>] SyS_mmap_pgoff+0x1d7/0x280 Jun 14 18:44:07 test-media kernel: [ 49.376709] [<ffffffff81007f8d>] SyS_mmap+0x1d/0x20 Jun 14 18:44:07 test-media kernel: [ 49.376714] [<ffffffff819b44ae>] 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] [<ffffffff810d79b3>] __lock_acquire+0x1fd3/0x2070 Jun 14 18:44:07 test-media kernel: [ 49.376720] [<ffffffff810d852c>] lock_acquire+0x6c/0xa0 Jun 14 18:44:07 test-media kernel: [ 49.376721] [<ffffffff819b1a92>] down_read+0x42/0x60 Jun 14 18:44:07 test-media kernel: [ 49.376723] [<ffffffffa03a81f6>] vb2_vmalloc_put_userptr+0x36/0x110 [videobuf2_vmalloc] Jun 14 18:44:07 test-media kernel: [ 49.376725] [<ffffffffa0394626>] __vb2_queue_free+0x146/0x5e0 [videobuf2_core] Jun 14 18:44:07 test-media kernel: [ 49.376727] [<ffffffffa0398dd3>] vb2_queue_release+0x33/0x40 [videobuf2_core] Jun 14 18:44:07 test-media kernel: [ 49.376729] [<ffffffffa0398e75>] _vb2_fop_release+0x95/0xb0 [videobuf2_core] Jun 14 18:44:07 test-media kernel: [ 49.376731] [<ffffffffa0398eb9>] vb2_fop_release+0x29/0x50 [videobuf2_core] Jun 14 18:44:07 test-media kernel: [ 49.376733] [<ffffffffa03b6372>] vivid_fop_release+0x92/0x230 [vivid] Jun 14 18:44:07 test-media kernel: [ 49.376737] [<ffffffffa0361460>] v4l2_release+0x30/0x80 [videodev] Jun 14 18:44:07 test-media kernel: [ 49.376739] [<ffffffff811a51d5>] __fput+0xe5/0x200 Jun 14 18:44:07 test-media kernel: [ 49.376744] [<ffffffff811a5339>] ____fput+0x9/0x10 Jun 14 18:44:07 test-media kernel: [ 49.376746] [<ffffffff810a9fa4>] task_work_run+0xc4/0xf0 Jun 14 18:44:07 test-media kernel: [ 49.376749] [<ffffffff81002dd1>] do_notify_resume+0x41/0x60 Jun 14 18:44:07 test-media kernel: [ 49.376752] [<ffffffff819b46a6>] 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: [<ffffffffa0398e0a>] _vb2_fop_release+0x2a/0xb0 [videobuf2_core] Jun 14 18:44:07 test-media kernel: [ 49.376770] #1: (&q->mmap_lock){+.+...}, at: [<ffffffffa0398dc5>] 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] [<ffffffff819a7aac>] dump_stack+0x4f/0x7b Jun 14 18:44:07 test-media kernel: [ 49.376792] [<ffffffff819a3964>] print_circular_bug+0x20f/0x251 Jun 14 18:44:07 test-media kernel: [ 49.376793] [<ffffffff810d79b3>] __lock_acquire+0x1fd3/0x2070 Jun 14 18:44:07 test-media kernel: [ 49.376795] [<ffffffff810d6543>] ? __lock_acquire+0xb63/0x2070 Jun 14 18:44:07 test-media kernel: [ 49.376797] [<ffffffff810d37a8>] ? __lock_is_held+0x58/0x80 Jun 14 18:44:07 test-media kernel: [ 49.376798] [<ffffffff810d852c>] lock_acquire+0x6c/0xa0 Jun 14 18:44:07 test-media kernel: [ 49.376800] [<ffffffffa03a81f6>] ? vb2_vmalloc_put_userptr+0x36/0x110 [videobuf2_vmalloc] Jun 14 18:44:07 test-media kernel: [ 49.376802] [<ffffffff819b1a92>] down_read+0x42/0x60 Jun 14 18:44:07 test-media kernel: [ 49.376803] [<ffffffffa03a81f6>] ? vb2_vmalloc_put_userptr+0x36/0x110 [videobuf2_vmalloc] Jun 14 18:44:07 test-media kernel: [ 49.376805] [<ffffffff819af1b1>] ? mutex_lock_nested+0x2b1/0x560 Jun 14 18:44:07 test-media kernel: [ 49.376807] [<ffffffffa0398dc5>] ? vb2_queue_release+0x25/0x40 [videobuf2_core] Jun 14 18:44:07 test-media kernel: [ 49.376808] [<ffffffffa03a81f6>] vb2_vmalloc_put_userptr+0x36/0x110 [videobuf2_vmalloc] Jun 14 18:44:07 test-media kernel: [ 49.376810] [<ffffffffa0398e0a>] ? _vb2_fop_release+0x2a/0xb0 [videobuf2_core] Jun 14 18:44:07 test-media kernel: [ 49.376812] [<ffffffffa0394626>] __vb2_queue_free+0x146/0x5e0 [videobuf2_core] Jun 14 18:44:07 test-media kernel: [ 49.376814] [<ffffffffa0398dd3>] vb2_queue_release+0x33/0x40 [videobuf2_core] Jun 14 18:44:07 test-media kernel: [ 49.376816] [<ffffffffa0398e75>] _vb2_fop_release+0x95/0xb0 [videobuf2_core] Jun 14 18:44:07 test-media kernel: [ 49.376818] [<ffffffffa0398eb9>] vb2_fop_release+0x29/0x50 [videobuf2_core] Jun 14 18:44:07 test-media kernel: [ 49.376820] [<ffffffffa03b6372>] vivid_fop_release+0x92/0x230 [vivid] Jun 14 18:44:07 test-media kernel: [ 49.376822] [<ffffffffa0361460>] v4l2_release+0x30/0x80 [videodev] Jun 14 18:44:07 test-media kernel: [ 49.376824] [<ffffffff811a51d5>] __fput+0xe5/0x200 Jun 14 18:44:07 test-media kernel: [ 49.376825] [<ffffffff819b4653>] ? int_very_careful+0x5/0x46 Jun 14 18:44:07 test-media kernel: [ 49.376827] [<ffffffff811a5339>] ____fput+0x9/0x10 Jun 14 18:44:07 test-media kernel: [ 49.376828] [<ffffffff810a9fa4>] task_work_run+0xc4/0xf0 Jun 14 18:44:07 test-media kernel: [ 49.376830] [<ffffffff81002dd1>] do_notify_resume+0x41/0x60 Jun 14 18:44:07 test-media kernel: [ 49.376832] [<ffffffff819b46a6>] 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 <hans.verkuil@cisco.com> Cc: Jan Kara <jack@suse.cz> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Diffstat (limited to 'drivers/media/v4l2-core/videobuf2-vmalloc.c')
-rw-r--r--drivers/media/v4l2-core/videobuf2-vmalloc.c6
1 files changed, 1 insertions, 5 deletions
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(&current->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(&current->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(&current->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(&current->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(&current->mm->mmap_sem);
kfree(buf);
}

Privacy Policy