From 2fc11536cf5c0b8eb4eb7e01a2a672a189e9280f Mon Sep 17 00:00:00 2001 From: Hans Verkuil Date: Tue, 7 Sep 2010 06:10:45 -0300 Subject: V4L/DVB: videobuf-dma-sg: set correct size in last sg element This fixes a nasty memory corruption bug when using userptr I/O. The function videobuf_pages_to_sg() sets up the scatter-gather list for the DMA transfer to the userspace pages. The first transfer is setup correctly (the size is set to PAGE_SIZE - offset), but all other transfers have size PAGE_SIZE. This is wrong for the last transfer which may be less than PAGE_SIZE. Most, if not all, drivers will program the boards DMA engine correctly, i.e. even though the size in the last sg element is wrong, they will do their own size calculations and make sure the right amount is DMA-ed, and so seemingly prevent memory corruption. However, behind the scenes the dynamic DMA mapping support (in lib/swiotlb.c) may create bounce buffers if the memory pages are not in DMA-able memory. This happens for example on a 64-bit linux with a board that only supports 32-bit DMA. These bounce buffers DO use the information in the sg list to determine the size. So while the DMA engine transfers the correct amount of data, when the data is 'bounced' back too much is copied, causing buffer overwrites. The fix is simple: calculate and set the correct size for the last sg list element. Signed-off-by: Hans Verkuil Cc: stable@kernel.org Signed-off-by: Mauro Carvalho Chehab --- include/media/videobuf-dma-sg.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/media/videobuf-dma-sg.h b/include/media/videobuf-dma-sg.h index 97e07f46a0fa..aa4ebb42a565 100644 --- a/include/media/videobuf-dma-sg.h +++ b/include/media/videobuf-dma-sg.h @@ -48,6 +48,7 @@ struct videobuf_dmabuf { /* for userland buffer */ int offset; + size_t size; struct page **pages; /* for kernel buffers */ -- cgit v1.2.2 From 1df6a2ebd75067aefbdf07482bf8e3d0584e04ee Mon Sep 17 00:00:00 2001 From: Thomas Hellstrom Date: Thu, 30 Sep 2010 12:36:45 +0200 Subject: drm/ttm: Fix two race conditions + fix busy codepaths This fixes a race pointed out by Dave Airlie where we don't take a buffer object about to be destroyed off the LRU lists properly. It also fixes a rare case where a buffer object could be destroyed in the middle of an accelerated eviction. The patch also adds a utility function that can be used to prematurely release GPU memory space usage of an object waiting to be destroyed. For example during eviction or swapout. The above mentioned commit didn't queue the buffer on the delayed destroy list under some rare circumstances. It also didn't completely honor the remove_all parameter. Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=615505 http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=591061 Signed-off-by: Thomas Hellstrom Signed-off-by: Dave Airlie --- include/drm/ttm/ttm_bo_api.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h index 267a86c74e2e..2040e6c4f172 100644 --- a/include/drm/ttm/ttm_bo_api.h +++ b/include/drm/ttm/ttm_bo_api.h @@ -246,9 +246,11 @@ struct ttm_buffer_object { atomic_t reserved; - /** * Members protected by the bo::lock + * In addition, setting sync_obj to anything else + * than NULL requires bo::reserved to be held. This allows for + * checking NULL while reserved but not holding bo::lock. */ void *sync_obj_arg; -- cgit v1.2.2 From 430c62fb2948d964cf8dc7f3e2f69623c04ef62f Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 7 Oct 2010 09:35:16 +0200 Subject: elevator: fix oops on early call to elevator_change() 2.6.36 introduces an API for drivers to switch the IO scheduler instead of manually calling the elevator exit and init functions. This API was added since q->elevator must be cleared in between those two calls. And since we already have this functionality directly from use by the sysfs interface to switch schedulers online, it was prudent to reuse it internally too. But this API needs the queue to be in a fully initialized state before it is called, or it will attempt to unregister elevator kobjects before they have been added. This results in an oops like this: BUG: unable to handle kernel NULL pointer dereference at 0000000000000051 IP: [] sysfs_create_dir+0x2e/0xc0 PGD 47ddfc067 PUD 47c6a1067 PMD 0 Oops: 0000 [#1] PREEMPT SMP last sysfs file: /sys/devices/pci0000:00/0000:00:02.0/0000:04:00.1/irq CPU 2 Modules linked in: t(+) loop hid_apple usbhid ahci ehci_hcd uhci_hcd libahci usbcore nls_base igb Pid: 7319, comm: modprobe Not tainted 2.6.36-rc6+ #132 QSSC-S4R/QSSC-S4R RIP: 0010:[] [] sysfs_create_dir+0x2e/0xc0 RSP: 0018:ffff88027da25d08 EFLAGS: 00010246 RAX: ffff88047c68c528 RBX: 00000000fffffffe RCX: 0000000000000000 RDX: 000000000000002f RSI: 000000000000002f RDI: ffff88047e196c88 RBP: ffff88027da25d38 R08: 0000000000000000 R09: d84156c5635688c0 R10: d84156c5635688c0 R11: 0000000000000000 R12: ffff88047e196c88 R13: 0000000000000000 R14: 0000000000000000 R15: ffff88047c68c528 FS: 00007fcb0b26f6e0(0000) GS:ffff880287400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000051 CR3: 000000047e76e000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process modprobe (pid: 7319, threadinfo ffff88027da24000, task ffff88027d377090) Stack: ffff88027da25d58 ffff88047c68c528 00000000fffffffe ffff88047e196c88 <0> ffff88047c68c528 ffff88047e05bd90 ffff88027da25d78 ffffffff8123fb77 <0> ffff88047e05bd90 0000000000000000 ffff88047e196c88 ffff88047c68c528 Call Trace: [] kobject_add_internal+0xe7/0x1f0 [] kobject_add_varg+0x38/0x60 [] kobject_add+0x69/0x90 [] ? sysfs_remove_dir+0x20/0xa0 [] ? sub_preempt_count+0x9d/0xe0 [] ? _raw_spin_unlock+0x30/0x50 [] ? sysfs_remove_dir+0x20/0xa0 [] ? sysfs_remove_dir+0x34/0xa0 [] elv_register_queue+0x34/0xa0 [] elevator_change+0xfd/0x250 [] ? t_init+0x0/0x361 [t] [] ? t_init+0x0/0x361 [t] [] t_init+0xa8/0x361 [t] [] do_one_initcall+0x3e/0x170 [] sys_init_module+0xbd/0x220 [] system_call_fastpath+0x16/0x1b Code: e5 41 56 41 55 41 54 49 89 fc 53 48 83 ec 10 48 85 ff 74 52 48 8b 47 18 49 c7 c5 00 46 61 81 48 85 c0 74 04 4c 8b 68 30 45 31 f6 <41> 80 7d 51 00 74 0e 49 8b 44 24 28 4c 89 e7 ff 50 20 49 89 c6 RIP [] sysfs_create_dir+0x2e/0xc0 RSP CR2: 0000000000000051 ---[ end trace a6541d3bf07945df ]--- Fix this by adding a registered bit to the elevator queue, which is set when the sysfs kobjects have been registered. Signed-off-by: Jens Axboe --- include/linux/elevator.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/elevator.h b/include/linux/elevator.h index 926b50322a46..4fd978e7eb83 100644 --- a/include/linux/elevator.h +++ b/include/linux/elevator.h @@ -93,6 +93,7 @@ struct elevator_queue struct elevator_type *elevator_type; struct mutex sysfs_lock; struct hlist_head *hash; + unsigned int registered:1; }; /* -- cgit v1.2.2