linux/drivers/char/virtio_console.c

2229 lines
52 KiB

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 17:04:11 +09:00
virtio: virtio_console: fix DMA memory allocation for rproc serial Since commit 086d08725d34 ("remoteproc: create vdev subdevice with specific dma memory pool"), every remoteproc has a DMA subdevice ("remoteprocX#vdevYbuffer") for each virtio device, which inherits DMA capabilities from the corresponding platform device. This allowed to associate different DMA pools with each vdev, and required from virtio drivers to perform DMA operations with the parent device (vdev->dev.parent) instead of grandparent (vdev->dev.parent->parent). virtio_rpmsg_bus was already changed in the same merge cycle with commit d999b622fcfb ("rpmsg: virtio: allocate buffer from parent"), but virtio_console did not. In fact, operations using the grandparent worked fine while the grandparent was the platform device, but since commit c774ad010873 ("remoteproc: Fix and restore the parenting hierarchy for vdev") this was changed, and now the grandparent device is the remoteproc device without any DMA capabilities. So, starting v5.8-rc1 the following warning is observed: [ 2.483925] ------------[ cut here ]------------ [ 2.489148] WARNING: CPU: 3 PID: 101 at kernel/dma/mapping.c:427 0x80e7eee8 [ 2.489152] Modules linked in: virtio_console(+) [ 2.503737] virtio_rpmsg_bus rpmsg_core [ 2.508903] [ 2.528898] <Other modules, stack and call trace here> [ 2.913043] [ 2.914907] ---[ end trace 93ac8746beab612c ]--- [ 2.920102] virtio-ports vport1p0: Error allocating inbufs kernel/dma/mapping.c:427 is: WARN_ON_ONCE(!dev->coherent_dma_mask); obviously because the grandparent now is remoteproc dev without any DMA caps: [ 3.104943] Parent: remoteproc0#vdev1buffer, grandparent: remoteproc0 Fix this the same way as it was for virtio_rpmsg_bus, using just the parent device (vdev->dev.parent, "remoteprocX#vdevYbuffer") for DMA operations. This also allows now to reserve DMA pools/buffers for rproc serial via Device Tree. Fixes: c774ad010873 ("remoteproc: Fix and restore the parenting hierarchy for vdev") Cc: stable@vger.kernel.org # 5.1+ Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Alexander Lobakin <alobakin@pm.me> Date: Thu, 5 Nov 2020 11:10:24 +0800 Link: https://lore.kernel.org/r/AOKowLclCbOCKxyiJ71WeNyuAAj2q8EUtxrXbyky5E@cp7-web-042.plabs.ch Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-04 15:31:36 +00:00
virtio: virtio_console: fix DMA memory allocation for rproc serial Since commit 086d08725d34 ("remoteproc: create vdev subdevice with specific dma memory pool"), every remoteproc has a DMA subdevice ("remoteprocX#vdevYbuffer") for each virtio device, which inherits DMA capabilities from the corresponding platform device. This allowed to associate different DMA pools with each vdev, and required from virtio drivers to perform DMA operations with the parent device (vdev->dev.parent) instead of grandparent (vdev->dev.parent->parent). virtio_rpmsg_bus was already changed in the same merge cycle with commit d999b622fcfb ("rpmsg: virtio: allocate buffer from parent"), but virtio_console did not. In fact, operations using the grandparent worked fine while the grandparent was the platform device, but since commit c774ad010873 ("remoteproc: Fix and restore the parenting hierarchy for vdev") this was changed, and now the grandparent device is the remoteproc device without any DMA capabilities. So, starting v5.8-rc1 the following warning is observed: [ 2.483925] ------------[ cut here ]------------ [ 2.489148] WARNING: CPU: 3 PID: 101 at kernel/dma/mapping.c:427 0x80e7eee8 [ 2.489152] Modules linked in: virtio_console(+) [ 2.503737] virtio_rpmsg_bus rpmsg_core [ 2.508903] [ 2.528898] <Other modules, stack and call trace here> [ 2.913043] [ 2.914907] ---[ end trace 93ac8746beab612c ]--- [ 2.920102] virtio-ports vport1p0: Error allocating inbufs kernel/dma/mapping.c:427 is: WARN_ON_ONCE(!dev->coherent_dma_mask); obviously because the grandparent now is remoteproc dev without any DMA caps: [ 3.104943] Parent: remoteproc0#vdev1buffer, grandparent: remoteproc0 Fix this the same way as it was for virtio_rpmsg_bus, using just the parent device (vdev->dev.parent, "remoteprocX#vdevYbuffer") for DMA operations. This also allows now to reserve DMA pools/buffers for rproc serial via Device Tree. Fixes: c774ad010873 ("remoteproc: Fix and restore the parenting hierarchy for vdev") Cc: stable@vger.kernel.org # 5.1+ Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Alexander Lobakin <alobakin@pm.me> Date: Thu, 5 Nov 2020 11:10:24 +0800 Link: https://lore.kernel.org/r/AOKowLclCbOCKxyiJ71WeNyuAAj2q8EUtxrXbyky5E@cp7-web-042.plabs.ch Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-04 15:31:36 +00:00
virtio/console: Add pipe_lock/unlock for splice_write Add pipe_lock/unlock for splice_write to avoid oops by following competition: (1) An application gets fds of a trace buffer, virtio-serial, pipe. (2) The application does fork() (3) The processes execute splice_read(trace buffer) and splice_write(virtio-serial) via same pipe. <parent> <child> get fds of a trace buffer, virtio-serial, pipe | fork()----------create--------+ | | splice(read) | ---+ splice(write) | +-- no competition | splice(read) | | splice(write) ---+ | | splice(read) | splice(write) splice(read) ------ competition | splice(write) Two processes share a pipe_inode_info structure. If the child execute splice(read) when the parent tries to execute splice(write), the structure can be broken. Existing virtio-serial driver does not get lock for the structure in splice_write, so this competition will induce oops. <oops messages> BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 IP: [<ffffffff811a6b5f>] splice_from_pipe_feed+0x6f/0x130 PGD 7223e067 PUD 72391067 PMD 0 Oops: 0000 [#1] SMP Modules linked in: lockd bnep bluetooth rfkill sunrpc ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables snd_hda_intel snd_hda_codec snd_hwdep snd_pcm snd_page_alloc snd_timer snd soundcore pcspkr virtio_net virtio_balloon i2c_piix4 i2c_core microcode uinput floppy CPU: 0 PID: 1072 Comm: compete-test Not tainted 3.10.0ws+ #55 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007 task: ffff880071b98000 ti: ffff88007b55e000 task.ti: ffff88007b55e000 RIP: 0010:[<ffffffff811a6b5f>] [<ffffffff811a6b5f>] splice_from_pipe_feed+0x6f/0x130 RSP: 0018:ffff88007b55fd78 EFLAGS: 00010287 RAX: 0000000000000000 RBX: ffff88007b55fe20 RCX: 0000000000000000 RDX: 0000000000001000 RSI: ffff88007a95ba30 RDI: ffff880036f9e6c0 RBP: ffff88007b55fda8 R08: 00000000000006ec R09: ffff880077626708 R10: 0000000000000003 R11: ffffffff8139ca59 R12: ffff88007a95ba30 R13: 0000000000000000 R14: ffffffff8139dd00 R15: ffff880036f9e6c0 FS: 00007f2e2e3a0740(0000) GS:ffff88007fc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000018 CR3: 0000000071bd1000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Stack: ffffffff8139ca59 ffff88007b55fe20 ffff880036f9e6c0 ffffffff8139dd00 ffff8800776266c0 ffff880077626708 ffff88007b55fde8 ffffffff811a6e8e ffff88007b55fde8 ffffffff8139ca59 ffff880036f9e6c0 ffff88007b55fe20 Call Trace: [<ffffffff8139ca59>] ? alloc_buf.isra.13+0x39/0xb0 [<ffffffff8139dd00>] ? virtcons_restore+0x100/0x100 [<ffffffff811a6e8e>] __splice_from_pipe+0x7e/0x90 [<ffffffff8139ca59>] ? alloc_buf.isra.13+0x39/0xb0 [<ffffffff8139d739>] port_fops_splice_write+0xe9/0x140 [<ffffffff8127a3f4>] ? selinux_file_permission+0xc4/0x120 [<ffffffff8139d650>] ? wait_port_writable+0x1b0/0x1b0 [<ffffffff811a6fe0>] do_splice_from+0xa0/0x110 [<ffffffff811a951f>] SyS_splice+0x5ff/0x6b0 [<ffffffff8161facf>] tracesys+0xdd/0xe2 Code: 49 8b 87 80 00 00 00 4c 8d 24 d0 8b 53 04 41 8b 44 24 0c 4d 8b 6c 24 10 39 d0 89 03 76 02 89 13 49 8b 44 24 10 4c 89 e6 4c 89 ff <ff> 50 18 85 c0 0f 85 aa 00 00 00 48 89 da 4c 89 e6 4c 89 ff 41 RIP [<ffffffff811a6b5f>] splice_from_pipe_feed+0x6f/0x130 RSP <ffff88007b55fd78> CR2: 0000000000000018 ---[ end trace 24572beb7764de59 ]--- V2: Fix a locking problem for error V3: Add Reviewed-by lines and stable@ line in sign-off area Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com> Reviewed-by: Amit Shah <amit.shah@redhat.com> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Amit Shah <amit.shah@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: stable@vger.kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-07-23 11:30:49 +09:30
fs/pipe: add simpler helpers for common cases The fix to atomically read the pipe head and tail state when not holding the pipe mutex has caused a number of headaches due to the size change of the involved types. It turns out that we don't have _that_ many places that access these fields directly and were affected, but we have more than we strictly should have, because our low-level helper functions have been designed to have intimate knowledge of how the pipes work. And as a result, that random noise of direct 'pipe->head' and 'pipe->tail' accesses makes it harder to pinpoint any actual potential problem spots remaining. For example, we didn't have a "is the pipe full" helper function, but instead had a "given these pipe buffer indexes and this pipe size, is the pipe full". That's because some low-level pipe code does actually want that much more complicated interface. But most other places literally just want a "is the pipe full" helper, and not having it meant that those places ended up being unnecessarily much too aware of this all. It would have been much better if only the very core pipe code that cared had been the one aware of this all. So let's fix it - better late than never. This just introduces the trivial wrappers for "is this pipe full or empty" and to get how many pipe buffers are used, so that instead of writing if (pipe_full(pipe->head, pipe->tail, pipe->max_usage)) the places that literally just want to know if a pipe is full can just say if (pipe_is_full(pipe)) instead. The existing trivial cases were converted with a 'sed' script. This cuts down on the places that access pipe->head and pipe->tail directly outside of the pipe code (and core splice code) quite a lot. The splice code in particular still revels in doing the direct low-level accesses, and the fuse fuse_dev_splice_write() code also seems a bit unnecessarily eager to go very low-level, but it's at least a bit better than it used to be. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2025-03-06 18:25:35 -10:00
virtio/console: Add pipe_lock/unlock for splice_write Add pipe_lock/unlock for splice_write to avoid oops by following competition: (1) An application gets fds of a trace buffer, virtio-serial, pipe. (2) The application does fork() (3) The processes execute splice_read(trace buffer) and splice_write(virtio-serial) via same pipe. <parent> <child> get fds of a trace buffer, virtio-serial, pipe | fork()----------create--------+ | | splice(read) | ---+ splice(write) | +-- no competition | splice(read) | | splice(write) ---+ | | splice(read) | splice(write) splice(read) ------ competition | splice(write) Two processes share a pipe_inode_info structure. If the child execute splice(read) when the parent tries to execute splice(write), the structure can be broken. Existing virtio-serial driver does not get lock for the structure in splice_write, so this competition will induce oops. <oops messages> BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 IP: [<ffffffff811a6b5f>] splice_from_pipe_feed+0x6f/0x130 PGD 7223e067 PUD 72391067 PMD 0 Oops: 0000 [#1] SMP Modules linked in: lockd bnep bluetooth rfkill sunrpc ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables snd_hda_intel snd_hda_codec snd_hwdep snd_pcm snd_page_alloc snd_timer snd soundcore pcspkr virtio_net virtio_balloon i2c_piix4 i2c_core microcode uinput floppy CPU: 0 PID: 1072 Comm: compete-test Not tainted 3.10.0ws+ #55 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007 task: ffff880071b98000 ti: ffff88007b55e000 task.ti: ffff88007b55e000 RIP: 0010:[<ffffffff811a6b5f>] [<ffffffff811a6b5f>] splice_from_pipe_feed+0x6f/0x130 RSP: 0018:ffff88007b55fd78 EFLAGS: 00010287 RAX: 0000000000000000 RBX: ffff88007b55fe20 RCX: 0000000000000000 RDX: 0000000000001000 RSI: ffff88007a95ba30 RDI: ffff880036f9e6c0 RBP: ffff88007b55fda8 R08: 00000000000006ec R09: ffff880077626708 R10: 0000000000000003 R11: ffffffff8139ca59 R12: ffff88007a95ba30 R13: 0000000000000000 R14: ffffffff8139dd00 R15: ffff880036f9e6c0 FS: 00007f2e2e3a0740(0000) GS:ffff88007fc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000018 CR3: 0000000071bd1000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Stack: ffffffff8139ca59 ffff88007b55fe20 ffff880036f9e6c0 ffffffff8139dd00 ffff8800776266c0 ffff880077626708 ffff88007b55fde8 ffffffff811a6e8e ffff88007b55fde8 ffffffff8139ca59 ffff880036f9e6c0 ffff88007b55fe20 Call Trace: [<ffffffff8139ca59>] ? alloc_buf.isra.13+0x39/0xb0 [<ffffffff8139dd00>] ? virtcons_restore+0x100/0x100 [<ffffffff811a6e8e>] __splice_from_pipe+0x7e/0x90 [<ffffffff8139ca59>] ? alloc_buf.isra.13+0x39/0xb0 [<ffffffff8139d739>] port_fops_splice_write+0xe9/0x140 [<ffffffff8127a3f4>] ? selinux_file_permission+0xc4/0x120 [<ffffffff8139d650>] ? wait_port_writable+0x1b0/0x1b0 [<ffffffff811a6fe0>] do_splice_from+0xa0/0x110 [<ffffffff811a951f>] SyS_splice+0x5ff/0x6b0 [<ffffffff8161facf>] tracesys+0xdd/0xe2 Code: 49 8b 87 80 00 00 00 4c 8d 24 d0 8b 53 04 41 8b 44 24 0c 4d 8b 6c 24 10 39 d0 89 03 76 02 89 13 49 8b 44 24 10 4c 89 e6 4c 89 ff <ff> 50 18 85 c0 0f 85 aa 00 00 00 48 89 da 4c 89 e6 4c 89 ff 41 RIP [<ffffffff811a6b5f>] splice_from_pipe_feed+0x6f/0x130 RSP <ffff88007b55fd78> CR2: 0000000000000018 ---[ end trace 24572beb7764de59 ]--- V2: Fix a locking problem for error V3: Add Reviewed-by lines and stable@ line in sign-off area Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com> Reviewed-by: Amit Shah <amit.shah@redhat.com> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Amit Shah <amit.shah@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: stable@vger.kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-07-23 11:30:49 +09:30
virtio/console: Quit from splice_write if pipe->nrbufs is 0 Quit from splice_write if pipe->nrbufs is 0 for avoiding oops in virtio-serial. When an application was doing splice from a kernel buffer to virtio-serial on a guest, the application received signal(SIGINT). This situation will normally happen, but the kernel executed a kernel panic by oops as follows: BUG: unable to handle kernel paging request at ffff882071c8ef28 IP: [<ffffffff812de48f>] sg_init_table+0x2f/0x50 PGD 1fac067 PUD 0 Oops: 0000 [#1] SMP Modules linked in: lockd sunrpc bnep bluetooth rfkill ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables snd_hda_intel snd_hda_codec snd_hwdep snd_pcm snd_page_alloc snd_timer snd microcode virtio_balloon virtio_net pcspkr soundcore i2c_piix4 i2c_core uinput floppy CPU: 1 PID: 908 Comm: trace-cmd Not tainted 3.10.0+ #49 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007 task: ffff880071c64650 ti: ffff88007bf24000 task.ti: ffff88007bf24000 RIP: 0010:[<ffffffff812de48f>] [<ffffffff812de48f>] sg_init_table+0x2f/0x50 RSP: 0018:ffff88007bf25dd8 EFLAGS: 00010286 RAX: 0000001fffffffe0 RBX: ffff882071c8ef28 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff880071c8ef48 RBP: ffff88007bf25de8 R08: ffff88007fd15d40 R09: ffff880071c8ef48 R10: ffffea0001c71040 R11: ffffffff8139c555 R12: 0000000000000000 R13: ffff88007506a3c0 R14: ffff88007c862500 R15: ffff880071c8ef00 FS: 00007f0a3646c740(0000) GS:ffff88007fd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff882071c8ef28 CR3: 000000007acbb000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Stack: ffff880071c8ef48 ffff88007bf25e20 ffff88007bf25e88 ffffffff8139d6fa ffff88007bf25e28 ffffffff8127a3f4 0000000000000000 0000000000000000 ffff880071c8ef48 0000100000000000 0000000000000003 ffff88007bf25e08 Call Trace: [<ffffffff8139d6fa>] port_fops_splice_write+0xaa/0x130 [<ffffffff8127a3f4>] ? selinux_file_permission+0xc4/0x120 [<ffffffff8139d650>] ? wait_port_writable+0x1b0/0x1b0 [<ffffffff811a6fe0>] do_splice_from+0xa0/0x110 [<ffffffff811a951f>] SyS_splice+0x5ff/0x6b0 [<ffffffff8161f8c2>] system_call_fastpath+0x16/0x1b Code: c1 e2 05 48 89 e5 48 83 ec 10 4c 89 65 f8 41 89 f4 31 f6 48 89 5d f0 48 89 fb e8 8d ce ff ff 41 8d 44 24 ff 48 c1 e0 05 48 01 c3 <48> 8b 03 48 83 e0 fe 48 83 c8 02 48 89 03 48 8b 5d f0 4c 8b 65 RIP [<ffffffff812de48f>] sg_init_table+0x2f/0x50 RSP <ffff88007bf25dd8> CR2: ffff882071c8ef28 ---[ end trace 86323505eb42ea8f ]--- It seems to induce pagefault in sg_init_tabel() when pipe->nrbufs is equal to zero. This may happen in a following situation: (1) The application normally does splice(read) from a kernel buffer, then does splice(write) to virtio-serial. (2) The application receives SIGINT when is doing splice(read), so splice(read) is failed by EINTR. However, the application does not finish the operation. (3) The application tries to do splice(write) without pipe->nrbufs. (4) The virtio-console driver tries to touch scatterlist structure sgl in sg_init_table(), but the region is out of bound. To avoid the case, a kernel should check whether pipe->nrbufs is empty or not when splice_write is executed in the virtio-console driver. V3: Add Reviewed-by lines and stable@ line in sign-off area. Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com> Reviewed-by: Amit Shah <amit.shah@redhat.com> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Amit Shah <amit.shah@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: stable@vger.kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-07-23 11:30:49 +09:30
virtio/console: Add pipe_lock/unlock for splice_write Add pipe_lock/unlock for splice_write to avoid oops by following competition: (1) An application gets fds of a trace buffer, virtio-serial, pipe. (2) The application does fork() (3) The processes execute splice_read(trace buffer) and splice_write(virtio-serial) via same pipe. <parent> <child> get fds of a trace buffer, virtio-serial, pipe | fork()----------create--------+ | | splice(read) | ---+ splice(write) | +-- no competition | splice(read) | | splice(write) ---+ | | splice(read) | splice(write) splice(read) ------ competition | splice(write) Two processes share a pipe_inode_info structure. If the child execute splice(read) when the parent tries to execute splice(write), the structure can be broken. Existing virtio-serial driver does not get lock for the structure in splice_write, so this competition will induce oops. <oops messages> BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 IP: [<ffffffff811a6b5f>] splice_from_pipe_feed+0x6f/0x130 PGD 7223e067 PUD 72391067 PMD 0 Oops: 0000 [#1] SMP Modules linked in: lockd bnep bluetooth rfkill sunrpc ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables snd_hda_intel snd_hda_codec snd_hwdep snd_pcm snd_page_alloc snd_timer snd soundcore pcspkr virtio_net virtio_balloon i2c_piix4 i2c_core microcode uinput floppy CPU: 0 PID: 1072 Comm: compete-test Not tainted 3.10.0ws+ #55 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007 task: ffff880071b98000 ti: ffff88007b55e000 task.ti: ffff88007b55e000 RIP: 0010:[<ffffffff811a6b5f>] [<ffffffff811a6b5f>] splice_from_pipe_feed+0x6f/0x130 RSP: 0018:ffff88007b55fd78 EFLAGS: 00010287 RAX: 0000000000000000 RBX: ffff88007b55fe20 RCX: 0000000000000000 RDX: 0000000000001000 RSI: ffff88007a95ba30 RDI: ffff880036f9e6c0 RBP: ffff88007b55fda8 R08: 00000000000006ec R09: ffff880077626708 R10: 0000000000000003 R11: ffffffff8139ca59 R12: ffff88007a95ba30 R13: 0000000000000000 R14: ffffffff8139dd00 R15: ffff880036f9e6c0 FS: 00007f2e2e3a0740(0000) GS:ffff88007fc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000018 CR3: 0000000071bd1000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Stack: ffffffff8139ca59 ffff88007b55fe20 ffff880036f9e6c0 ffffffff8139dd00 ffff8800776266c0 ffff880077626708 ffff88007b55fde8 ffffffff811a6e8e ffff88007b55fde8 ffffffff8139ca59 ffff880036f9e6c0 ffff88007b55fe20 Call Trace: [<ffffffff8139ca59>] ? alloc_buf.isra.13+0x39/0xb0 [<ffffffff8139dd00>] ? virtcons_restore+0x100/0x100 [<ffffffff811a6e8e>] __splice_from_pipe+0x7e/0x90 [<ffffffff8139ca59>] ? alloc_buf.isra.13+0x39/0xb0 [<ffffffff8139d739>] port_fops_splice_write+0xe9/0x140 [<ffffffff8127a3f4>] ? selinux_file_permission+0xc4/0x120 [<ffffffff8139d650>] ? wait_port_writable+0x1b0/0x1b0 [<ffffffff811a6fe0>] do_splice_from+0xa0/0x110 [<ffffffff811a951f>] SyS_splice+0x5ff/0x6b0 [<ffffffff8161facf>] tracesys+0xdd/0xe2 Code: 49 8b 87 80 00 00 00 4c 8d 24 d0 8b 53 04 41 8b 44 24 0c 4d 8b 6c 24 10 39 d0 89 03 76 02 89 13 49 8b 44 24 10 4c 89 e6 4c 89 ff <ff> 50 18 85 c0 0f 85 aa 00 00 00 48 89 da 4c 89 e6 4c 89 ff 41 RIP [<ffffffff811a6b5f>] splice_from_pipe_feed+0x6f/0x130 RSP <ffff88007b55fd78> CR2: 0000000000000018 ---[ end trace 24572beb7764de59 ]--- V2: Fix a locking problem for error V3: Add Reviewed-by lines and stable@ line in sign-off area Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com> Reviewed-by: Amit Shah <amit.shah@redhat.com> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Amit Shah <amit.shah@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: stable@vger.kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-07-23 11:30:49 +09:30
fs/pipe: add simpler helpers for common cases The fix to atomically read the pipe head and tail state when not holding the pipe mutex has caused a number of headaches due to the size change of the involved types. It turns out that we don't have _that_ many places that access these fields directly and were affected, but we have more than we strictly should have, because our low-level helper functions have been designed to have intimate knowledge of how the pipes work. And as a result, that random noise of direct 'pipe->head' and 'pipe->tail' accesses makes it harder to pinpoint any actual potential problem spots remaining. For example, we didn't have a "is the pipe full" helper function, but instead had a "given these pipe buffer indexes and this pipe size, is the pipe full". That's because some low-level pipe code does actually want that much more complicated interface. But most other places literally just want a "is the pipe full" helper, and not having it meant that those places ended up being unnecessarily much too aware of this all. It would have been much better if only the very core pipe code that cared had been the one aware of this all. So let's fix it - better late than never. This just introduces the trivial wrappers for "is this pipe full or empty" and to get how many pipe buffers are used, so that instead of writing if (pipe_full(pipe->head, pipe->tail, pipe->max_usage)) the places that literally just want to know if a pipe is full can just say if (pipe_is_full(pipe)) instead. The existing trivial cases were converted with a 'sed' script. This cuts down on the places that access pipe->head and pipe->tail directly outside of the pipe code (and core splice code) quite a lot. The splice code in particular still revels in doing the direct low-level accesses, and the fuse fuse_dev_splice_write() code also seems a bit unnecessarily eager to go very low-level, but it's at least a bit better than it used to be. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2025-03-06 18:25:35 -10:00
Pipework for general notification queue -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEqG5UsNXhtOCrfGQP+7dXa6fLC2sFAl3O0OoACgkQ+7dXa6fL C2tAwA//VH9Y81azemXFdflDF90sSH3TCASlKHVYHbBNAkH/QP5F00G4BEM4nNqH F3x7qcU9vzfGdumF1pc90Yt6XSYlsQEGF+xMyMw/VS2wKs40yv+b/doVbzOWbN9C NfrklgHeuuBk+JzU2llDisVqKRTLt4SmDpYu1ZdcchUQFZCCl3BpgdSEC+xXrHay +KlRPVNMSd2kXMCDuSWrr71lVNdCTdf3nNC5p1i780+VrgpIBIG/jmiNdCcd7PLH 1aesPlr8UZY3+bmRtqe587fVRAhT2qA2xibKtyf9R0hrDtUKR4NSnpPmaeIjb26e LhVntcChhYxQqzy/T4ScTDNVjpSlwi6QMo5DwAwzNGf2nf/v5/CZ+vGYDVdXRFHj tgH1+8eDpHsi7jJp6E4cmZjiolsUx/ePDDTrQ4qbdDMO7fmIV6YQKFAMTLJepLBY qnJVqoBq3qn40zv6tVZmKgWiXQ65jEkBItZhEUmcQRBiSbBDPweIdEzx/mwzkX7U 1gShGdut6YP4GX7BnOhkiQmzucS85mgkUfG43+mBfYXb+4zNTEjhhkqhEduz2SQP xnjHxEM+MTGCj3PozIpJxNKzMTEceYY7cAUdNEMDQcHog7OCnIdGBIc7BPnsN8yA CPzntwP4mmLfK3weq3PIGC6d9xfc9PpmiR9docxQOvE6sk2Ifeo= =FKC7 -----END PGP SIGNATURE----- Merge tag 'notifications-pipe-prep-20191115' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs Pull pipe rework from David Howells: "This is my set of preparatory patches for building a general notification queue on top of pipes. It makes a number of significant changes: - It removes the nr_exclusive argument from __wake_up_sync_key() as this is always 1. This prepares for the next step: - Adds wake_up_interruptible_sync_poll_locked() so that poll can be woken up from a function that's holding the poll waitqueue spinlock. - Change the pipe buffer ring to be managed in terms of unbounded head and tail indices rather than bounded index and length. This means that reading the pipe only needs to modify one index, not two. - A selection of helper functions are provided to query the state of the pipe buffer, plus a couple to apply updates to the pipe indices. - The pipe ring is allowed to have kernel-reserved slots. This allows many notification messages to be spliced in by the kernel without allowing userspace to pin too many pages if it writes to the same pipe. - Advance the head and tail indices inside the pipe waitqueue lock and use wake_up_interruptible_sync_poll_locked() to poke poll without having to take the lock twice. - Rearrange pipe_write() to preallocate the buffer it is going to write into and then drop the spinlock. This allows kernel notifications to then be added the ring whilst it is filling the buffer it allocated. The read side is stalled because the pipe mutex is still held. - Don't wake up readers on a pipe if there was already data in it when we added more. - Don't wake up writers on a pipe if the ring wasn't full before we removed a buffer" * tag 'notifications-pipe-prep-20191115' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: pipe: Remove sync on wake_ups pipe: Increase the writer-wakeup threshold to reduce context-switch count pipe: Check for ring full inside of the spinlock in pipe_write() pipe: Remove redundant wakeup from pipe_write() pipe: Rearrange sequence in pipe_write() to preallocate slot pipe: Conditionalise wakeup in pipe_read() pipe: Advance tail pointer inside of wait spinlock in pipe_read() pipe: Allow pipes to have kernel-reserved slots pipe: Use head and tail pointers for the ring, not cursor and length Add wake_up_interruptible_sync_poll_locked() Remove the nr_exclusive argument from __wake_up_sync_key() pipe: Reduce #inclusion of pipe_fs_i.h
2019-11-30 14:12:13 -08:00
virtio/console: Add pipe_lock/unlock for splice_write Add pipe_lock/unlock for splice_write to avoid oops by following competition: (1) An application gets fds of a trace buffer, virtio-serial, pipe. (2) The application does fork() (3) The processes execute splice_read(trace buffer) and splice_write(virtio-serial) via same pipe. <parent> <child> get fds of a trace buffer, virtio-serial, pipe | fork()----------create--------+ | | splice(read) | ---+ splice(write) | +-- no competition | splice(read) | | splice(write) ---+ | | splice(read) | splice(write) splice(read) ------ competition | splice(write) Two processes share a pipe_inode_info structure. If the child execute splice(read) when the parent tries to execute splice(write), the structure can be broken. Existing virtio-serial driver does not get lock for the structure in splice_write, so this competition will induce oops. <oops messages> BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 IP: [<ffffffff811a6b5f>] splice_from_pipe_feed+0x6f/0x130 PGD 7223e067 PUD 72391067 PMD 0 Oops: 0000 [#1] SMP Modules linked in: lockd bnep bluetooth rfkill sunrpc ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables snd_hda_intel snd_hda_codec snd_hwdep snd_pcm snd_page_alloc snd_timer snd soundcore pcspkr virtio_net virtio_balloon i2c_piix4 i2c_core microcode uinput floppy CPU: 0 PID: 1072 Comm: compete-test Not tainted 3.10.0ws+ #55 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007 task: ffff880071b98000 ti: ffff88007b55e000 task.ti: ffff88007b55e000 RIP: 0010:[<ffffffff811a6b5f>] [<ffffffff811a6b5f>] splice_from_pipe_feed+0x6f/0x130 RSP: 0018:ffff88007b55fd78 EFLAGS: 00010287 RAX: 0000000000000000 RBX: ffff88007b55fe20 RCX: 0000000000000000 RDX: 0000000000001000 RSI: ffff88007a95ba30 RDI: ffff880036f9e6c0 RBP: ffff88007b55fda8 R08: 00000000000006ec R09: ffff880077626708 R10: 0000000000000003 R11: ffffffff8139ca59 R12: ffff88007a95ba30 R13: 0000000000000000 R14: ffffffff8139dd00 R15: ffff880036f9e6c0 FS: 00007f2e2e3a0740(0000) GS:ffff88007fc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000018 CR3: 0000000071bd1000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Stack: ffffffff8139ca59 ffff88007b55fe20 ffff880036f9e6c0 ffffffff8139dd00 ffff8800776266c0 ffff880077626708 ffff88007b55fde8 ffffffff811a6e8e ffff88007b55fde8 ffffffff8139ca59 ffff880036f9e6c0 ffff88007b55fe20 Call Trace: [<ffffffff8139ca59>] ? alloc_buf.isra.13+0x39/0xb0 [<ffffffff8139dd00>] ? virtcons_restore+0x100/0x100 [<ffffffff811a6e8e>] __splice_from_pipe+0x7e/0x90 [<ffffffff8139ca59>] ? alloc_buf.isra.13+0x39/0xb0 [<ffffffff8139d739>] port_fops_splice_write+0xe9/0x140 [<ffffffff8127a3f4>] ? selinux_file_permission+0xc4/0x120 [<ffffffff8139d650>] ? wait_port_writable+0x1b0/0x1b0 [<ffffffff811a6fe0>] do_splice_from+0xa0/0x110 [<ffffffff811a951f>] SyS_splice+0x5ff/0x6b0 [<ffffffff8161facf>] tracesys+0xdd/0xe2 Code: 49 8b 87 80 00 00 00 4c 8d 24 d0 8b 53 04 41 8b 44 24 0c 4d 8b 6c 24 10 39 d0 89 03 76 02 89 13 49 8b 44 24 10 4c 89 e6 4c 89 ff <ff> 50 18 85 c0 0f 85 aa 00 00 00 48 89 da 4c 89 e6 4c 89 ff 41 RIP [<ffffffff811a6b5f>] splice_from_pipe_feed+0x6f/0x130 RSP <ffff88007b55fd78> CR2: 0000000000000018 ---[ end trace 24572beb7764de59 ]--- V2: Fix a locking problem for error V3: Add Reviewed-by lines and stable@ line in sign-off area Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com> Reviewed-by: Amit Shah <amit.shah@redhat.com> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Amit Shah <amit.shah@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: stable@vger.kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-07-23 11:30:49 +09:30
virtio/console: Add pipe_lock/unlock for splice_write Add pipe_lock/unlock for splice_write to avoid oops by following competition: (1) An application gets fds of a trace buffer, virtio-serial, pipe. (2) The application does fork() (3) The processes execute splice_read(trace buffer) and splice_write(virtio-serial) via same pipe. <parent> <child> get fds of a trace buffer, virtio-serial, pipe | fork()----------create--------+ | | splice(read) | ---+ splice(write) | +-- no competition | splice(read) | | splice(write) ---+ | | splice(read) | splice(write) splice(read) ------ competition | splice(write) Two processes share a pipe_inode_info structure. If the child execute splice(read) when the parent tries to execute splice(write), the structure can be broken. Existing virtio-serial driver does not get lock for the structure in splice_write, so this competition will induce oops. <oops messages> BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 IP: [<ffffffff811a6b5f>] splice_from_pipe_feed+0x6f/0x130 PGD 7223e067 PUD 72391067 PMD 0 Oops: 0000 [#1] SMP Modules linked in: lockd bnep bluetooth rfkill sunrpc ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables snd_hda_intel snd_hda_codec snd_hwdep snd_pcm snd_page_alloc snd_timer snd soundcore pcspkr virtio_net virtio_balloon i2c_piix4 i2c_core microcode uinput floppy CPU: 0 PID: 1072 Comm: compete-test Not tainted 3.10.0ws+ #55 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007 task: ffff880071b98000 ti: ffff88007b55e000 task.ti: ffff88007b55e000 RIP: 0010:[<ffffffff811a6b5f>] [<ffffffff811a6b5f>] splice_from_pipe_feed+0x6f/0x130 RSP: 0018:ffff88007b55fd78 EFLAGS: 00010287 RAX: 0000000000000000 RBX: ffff88007b55fe20 RCX: 0000000000000000 RDX: 0000000000001000 RSI: ffff88007a95ba30 RDI: ffff880036f9e6c0 RBP: ffff88007b55fda8 R08: 00000000000006ec R09: ffff880077626708 R10: 0000000000000003 R11: ffffffff8139ca59 R12: ffff88007a95ba30 R13: 0000000000000000 R14: ffffffff8139dd00 R15: ffff880036f9e6c0 FS: 00007f2e2e3a0740(0000) GS:ffff88007fc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000018 CR3: 0000000071bd1000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Stack: ffffffff8139ca59 ffff88007b55fe20 ffff880036f9e6c0 ffffffff8139dd00 ffff8800776266c0 ffff880077626708 ffff88007b55fde8 ffffffff811a6e8e ffff88007b55fde8 ffffffff8139ca59 ffff880036f9e6c0 ffff88007b55fe20 Call Trace: [<ffffffff8139ca59>] ? alloc_buf.isra.13+0x39/0xb0 [<ffffffff8139dd00>] ? virtcons_restore+0x100/0x100 [<ffffffff811a6e8e>] __splice_from_pipe+0x7e/0x90 [<ffffffff8139ca59>] ? alloc_buf.isra.13+0x39/0xb0 [<ffffffff8139d739>] port_fops_splice_write+0xe9/0x140 [<ffffffff8127a3f4>] ? selinux_file_permission+0xc4/0x120 [<ffffffff8139d650>] ? wait_port_writable+0x1b0/0x1b0 [<ffffffff811a6fe0>] do_splice_from+0xa0/0x110 [<ffffffff811a951f>] SyS_splice+0x5ff/0x6b0 [<ffffffff8161facf>] tracesys+0xdd/0xe2 Code: 49 8b 87 80 00 00 00 4c 8d 24 d0 8b 53 04 41 8b 44 24 0c 4d 8b 6c 24 10 39 d0 89 03 76 02 89 13 49 8b 44 24 10 4c 89 e6 4c 89 ff <ff> 50 18 85 c0 0f 85 aa 00 00 00 48 89 da 4c 89 e6 4c 89 ff 41 RIP [<ffffffff811a6b5f>] splice_from_pipe_feed+0x6f/0x130 RSP <ffff88007b55fd78> CR2: 0000000000000018 ---[ end trace 24572beb7764de59 ]--- V2: Fix a locking problem for error V3: Add Reviewed-by lines and stable@ line in sign-off area Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com> Reviewed-by: Amit Shah <amit.shah@redhat.com> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Amit Shah <amit.shah@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: stable@vger.kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-07-23 11:30:49 +09:30
virtio/console: Add pipe_lock/unlock for splice_write Add pipe_lock/unlock for splice_write to avoid oops by following competition: (1) An application gets fds of a trace buffer, virtio-serial, pipe. (2) The application does fork() (3) The processes execute splice_read(trace buffer) and splice_write(virtio-serial) via same pipe. <parent> <child> get fds of a trace buffer, virtio-serial, pipe | fork()----------create--------+ | | splice(read) | ---+ splice(write) | +-- no competition | splice(read) | | splice(write) ---+ | | splice(read) | splice(write) splice(read) ------ competition | splice(write) Two processes share a pipe_inode_info structure. If the child execute splice(read) when the parent tries to execute splice(write), the structure can be broken. Existing virtio-serial driver does not get lock for the structure in splice_write, so this competition will induce oops. <oops messages> BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 IP: [<ffffffff811a6b5f>] splice_from_pipe_feed+0x6f/0x130 PGD 7223e067 PUD 72391067 PMD 0 Oops: 0000 [#1] SMP Modules linked in: lockd bnep bluetooth rfkill sunrpc ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables snd_hda_intel snd_hda_codec snd_hwdep snd_pcm snd_page_alloc snd_timer snd soundcore pcspkr virtio_net virtio_balloon i2c_piix4 i2c_core microcode uinput floppy CPU: 0 PID: 1072 Comm: compete-test Not tainted 3.10.0ws+ #55 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007 task: ffff880071b98000 ti: ffff88007b55e000 task.ti: ffff88007b55e000 RIP: 0010:[<ffffffff811a6b5f>] [<ffffffff811a6b5f>] splice_from_pipe_feed+0x6f/0x130 RSP: 0018:ffff88007b55fd78 EFLAGS: 00010287 RAX: 0000000000000000 RBX: ffff88007b55fe20 RCX: 0000000000000000 RDX: 0000000000001000 RSI: ffff88007a95ba30 RDI: ffff880036f9e6c0 RBP: ffff88007b55fda8 R08: 00000000000006ec R09: ffff880077626708 R10: 0000000000000003 R11: ffffffff8139ca59 R12: ffff88007a95ba30 R13: 0000000000000000 R14: ffffffff8139dd00 R15: ffff880036f9e6c0 FS: 00007f2e2e3a0740(0000) GS:ffff88007fc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000018 CR3: 0000000071bd1000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Stack: ffffffff8139ca59 ffff88007b55fe20 ffff880036f9e6c0 ffffffff8139dd00 ffff8800776266c0 ffff880077626708 ffff88007b55fde8 ffffffff811a6e8e ffff88007b55fde8 ffffffff8139ca59 ffff880036f9e6c0 ffff88007b55fe20 Call Trace: [<ffffffff8139ca59>] ? alloc_buf.isra.13+0x39/0xb0 [<ffffffff8139dd00>] ? virtcons_restore+0x100/0x100 [<ffffffff811a6e8e>] __splice_from_pipe+0x7e/0x90 [<ffffffff8139ca59>] ? alloc_buf.isra.13+0x39/0xb0 [<ffffffff8139d739>] port_fops_splice_write+0xe9/0x140 [<ffffffff8127a3f4>] ? selinux_file_permission+0xc4/0x120 [<ffffffff8139d650>] ? wait_port_writable+0x1b0/0x1b0 [<ffffffff811a6fe0>] do_splice_from+0xa0/0x110 [<ffffffff811a951f>] SyS_splice+0x5ff/0x6b0 [<ffffffff8161facf>] tracesys+0xdd/0xe2 Code: 49 8b 87 80 00 00 00 4c 8d 24 d0 8b 53 04 41 8b 44 24 0c 4d 8b 6c 24 10 39 d0 89 03 76 02 89 13 49 8b 44 24 10 4c 89 e6 4c 89 ff <ff> 50 18 85 c0 0f 85 aa 00 00 00 48 89 da 4c 89 e6 4c 89 ff 41 RIP [<ffffffff811a6b5f>] splice_from_pipe_feed+0x6f/0x130 RSP <ffff88007b55fd78> CR2: 0000000000000018 ---[ end trace 24572beb7764de59 ]--- V2: Fix a locking problem for error V3: Add Reviewed-by lines and stable@ line in sign-off area Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com> Reviewed-by: Amit Shah <amit.shah@redhat.com> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Amit Shah <amit.shah@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: stable@vger.kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-07-23 11:30:49 +09:30
virtio: console: Unlock vqs while freeing buffers Commit c6017e793b93 ("virtio: console: add locks around buffer removal in port unplug path") added locking around the freeing of buffers in the vq. However, when free_buf() is called with can_sleep = true and rproc is enabled, it calls dma_free_coherent() directly, requiring interrupts to be enabled. Currently a WARNING is triggered due to the spin locking around free_buf, with a call stack like this: WARNING: CPU: 3 PID: 121 at ./include/linux/dma-mapping.h:433 free_buf+0x1a8/0x288 Call Trace: [<8040c538>] show_stack+0x74/0xc0 [<80757240>] dump_stack+0xd0/0x110 [<80430d98>] __warn+0xfc/0x130 [<80430ee0>] warn_slowpath_null+0x2c/0x3c [<807e7c6c>] free_buf+0x1a8/0x288 [<807ea590>] remove_port_data+0x50/0xac [<807ea6a0>] unplug_port+0xb4/0x1bc [<807ea858>] virtcons_remove+0xb0/0xfc [<807b6734>] virtio_dev_remove+0x58/0xc0 [<807f918c>] __device_release_driver+0xac/0x134 [<807f924c>] device_release_driver+0x38/0x50 [<807f7edc>] bus_remove_device+0xfc/0x130 [<807f4b74>] device_del+0x17c/0x21c [<807f4c38>] device_unregister+0x24/0x38 [<807b6b50>] unregister_virtio_device+0x28/0x44 Fix this by restructuring the loops to allow the locks to only be taken where it is necessary to protect the vqs, and release it while the buffer is being freed. Fixes: c6017e793b93 ("virtio: console: add locks around buffer removal in port unplug path") Cc: stable@vger.kernel.org Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-10-11 12:05:15 +01:00
virtio: console: Unlock vqs while freeing buffers Commit c6017e793b93 ("virtio: console: add locks around buffer removal in port unplug path") added locking around the freeing of buffers in the vq. However, when free_buf() is called with can_sleep = true and rproc is enabled, it calls dma_free_coherent() directly, requiring interrupts to be enabled. Currently a WARNING is triggered due to the spin locking around free_buf, with a call stack like this: WARNING: CPU: 3 PID: 121 at ./include/linux/dma-mapping.h:433 free_buf+0x1a8/0x288 Call Trace: [<8040c538>] show_stack+0x74/0xc0 [<80757240>] dump_stack+0xd0/0x110 [<80430d98>] __warn+0xfc/0x130 [<80430ee0>] warn_slowpath_null+0x2c/0x3c [<807e7c6c>] free_buf+0x1a8/0x288 [<807ea590>] remove_port_data+0x50/0xac [<807ea6a0>] unplug_port+0xb4/0x1bc [<807ea858>] virtcons_remove+0xb0/0xfc [<807b6734>] virtio_dev_remove+0x58/0xc0 [<807f918c>] __device_release_driver+0xac/0x134 [<807f924c>] device_release_driver+0x38/0x50 [<807f7edc>] bus_remove_device+0xfc/0x130 [<807f4b74>] device_del+0x17c/0x21c [<807f4c38>] device_unregister+0x24/0x38 [<807b6b50>] unregister_virtio_device+0x28/0x44 Fix this by restructuring the loops to allow the locks to only be taken where it is necessary to protect the vqs, and release it while the buffer is being freed. Fixes: c6017e793b93 ("virtio: console: add locks around buffer removal in port unplug path") Cc: stable@vger.kernel.org Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-10-11 12:05:15 +01:00
virtio: console: clean up port data immediately at time of unplug We used to keep the port's char device structs and the /sys entries around till the last reference to the port was dropped. This is actually unnecessary, and resulted in buggy behaviour: 1. Open port in guest 2. Hot-unplug port 3. Hot-plug a port with the same 'name' property as the unplugged one This resulted in hot-plug being unsuccessful, as a port with the same name already exists (even though it was unplugged). This behaviour resulted in a warning message like this one: -------------------8<--------------------------------------- WARNING: at fs/sysfs/dir.c:512 sysfs_add_one+0xc9/0x130() (Not tainted) Hardware name: KVM sysfs: cannot create duplicate filename '/devices/pci0000:00/0000:00:04.0/virtio0/virtio-ports/vport0p1' Call Trace: [<ffffffff8106b607>] ? warn_slowpath_common+0x87/0xc0 [<ffffffff8106b6f6>] ? warn_slowpath_fmt+0x46/0x50 [<ffffffff811f2319>] ? sysfs_add_one+0xc9/0x130 [<ffffffff811f23e8>] ? create_dir+0x68/0xb0 [<ffffffff811f2469>] ? sysfs_create_dir+0x39/0x50 [<ffffffff81273129>] ? kobject_add_internal+0xb9/0x260 [<ffffffff812733d8>] ? kobject_add_varg+0x38/0x60 [<ffffffff812734b4>] ? kobject_add+0x44/0x70 [<ffffffff81349de4>] ? get_device_parent+0xf4/0x1d0 [<ffffffff8134b389>] ? device_add+0xc9/0x650 -------------------8<--------------------------------------- Instead of relying on guest applications to release all references to the ports, we should go ahead and unregister the port from all the core layers. Any open/read calls on the port will then just return errors, and an unplug/plug operation on the host will succeed as expected. This also caused buggy behaviour in case of the device removal (not just a port): when the device was removed (which means all ports on that device are removed automatically as well), the ports with active users would clean up only when the last references were dropped -- and it would be too late then to be referencing char device pointers, resulting in oopses: -------------------8<--------------------------------------- PID: 6162 TASK: ffff8801147ad500 CPU: 0 COMMAND: "cat" #0 [ffff88011b9d5a90] machine_kexec at ffffffff8103232b #1 [ffff88011b9d5af0] crash_kexec at ffffffff810b9322 #2 [ffff88011b9d5bc0] oops_end at ffffffff814f4a50 #3 [ffff88011b9d5bf0] die at ffffffff8100f26b #4 [ffff88011b9d5c20] do_general_protection at ffffffff814f45e2 #5 [ffff88011b9d5c50] general_protection at ffffffff814f3db5 [exception RIP: strlen+2] RIP: ffffffff81272ae2 RSP: ffff88011b9d5d00 RFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff880118901c18 RCX: 0000000000000000 RDX: ffff88011799982c RSI: 00000000000000d0 RDI: 3a303030302f3030 RBP: ffff88011b9d5d38 R8: 0000000000000006 R9: ffffffffa0134500 R10: 0000000000001000 R11: 0000000000001000 R12: ffff880117a1cc10 R13: 00000000000000d0 R14: 0000000000000017 R15: ffffffff81aff700 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #6 [ffff88011b9d5d00] kobject_get_path at ffffffff8126dc5d #7 [ffff88011b9d5d40] kobject_uevent_env at ffffffff8126e551 #8 [ffff88011b9d5dd0] kobject_uevent at ffffffff8126e9eb #9 [ffff88011b9d5de0] device_del at ffffffff813440c7 -------------------8<--------------------------------------- So clean up when we have all the context, and all that's left to do when the references to the port have dropped is to free up the port struct itself. CC: <stable@vger.kernel.org> Reported-by: chayang <chayang@redhat.com> Reported-by: YOGANANTH SUBRAMANIAN <anantyog@in.ibm.com> Reported-by: FuXiangChun <xfu@redhat.com> Reported-by: Qunfang Zhang <qzhang@redhat.com> Reported-by: Sibiao Luo <sluo@redhat.com> Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-07-29 14:20:29 +09:30
virtio: console: clean up port data immediately at time of unplug We used to keep the port's char device structs and the /sys entries around till the last reference to the port was dropped. This is actually unnecessary, and resulted in buggy behaviour: 1. Open port in guest 2. Hot-unplug port 3. Hot-plug a port with the same 'name' property as the unplugged one This resulted in hot-plug being unsuccessful, as a port with the same name already exists (even though it was unplugged). This behaviour resulted in a warning message like this one: -------------------8<--------------------------------------- WARNING: at fs/sysfs/dir.c:512 sysfs_add_one+0xc9/0x130() (Not tainted) Hardware name: KVM sysfs: cannot create duplicate filename '/devices/pci0000:00/0000:00:04.0/virtio0/virtio-ports/vport0p1' Call Trace: [<ffffffff8106b607>] ? warn_slowpath_common+0x87/0xc0 [<ffffffff8106b6f6>] ? warn_slowpath_fmt+0x46/0x50 [<ffffffff811f2319>] ? sysfs_add_one+0xc9/0x130 [<ffffffff811f23e8>] ? create_dir+0x68/0xb0 [<ffffffff811f2469>] ? sysfs_create_dir+0x39/0x50 [<ffffffff81273129>] ? kobject_add_internal+0xb9/0x260 [<ffffffff812733d8>] ? kobject_add_varg+0x38/0x60 [<ffffffff812734b4>] ? kobject_add+0x44/0x70 [<ffffffff81349de4>] ? get_device_parent+0xf4/0x1d0 [<ffffffff8134b389>] ? device_add+0xc9/0x650 -------------------8<--------------------------------------- Instead of relying on guest applications to release all references to the ports, we should go ahead and unregister the port from all the core layers. Any open/read calls on the port will then just return errors, and an unplug/plug operation on the host will succeed as expected. This also caused buggy behaviour in case of the device removal (not just a port): when the device was removed (which means all ports on that device are removed automatically as well), the ports with active users would clean up only when the last references were dropped -- and it would be too late then to be referencing char device pointers, resulting in oopses: -------------------8<--------------------------------------- PID: 6162 TASK: ffff8801147ad500 CPU: 0 COMMAND: "cat" #0 [ffff88011b9d5a90] machine_kexec at ffffffff8103232b #1 [ffff88011b9d5af0] crash_kexec at ffffffff810b9322 #2 [ffff88011b9d5bc0] oops_end at ffffffff814f4a50 #3 [ffff88011b9d5bf0] die at ffffffff8100f26b #4 [ffff88011b9d5c20] do_general_protection at ffffffff814f45e2 #5 [ffff88011b9d5c50] general_protection at ffffffff814f3db5 [exception RIP: strlen+2] RIP: ffffffff81272ae2 RSP: ffff88011b9d5d00 RFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff880118901c18 RCX: 0000000000000000 RDX: ffff88011799982c RSI: 00000000000000d0 RDI: 3a303030302f3030 RBP: ffff88011b9d5d38 R8: 0000000000000006 R9: ffffffffa0134500 R10: 0000000000001000 R11: 0000000000001000 R12: ffff880117a1cc10 R13: 00000000000000d0 R14: 0000000000000017 R15: ffffffff81aff700 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #6 [ffff88011b9d5d00] kobject_get_path at ffffffff8126dc5d #7 [ffff88011b9d5d40] kobject_uevent_env at ffffffff8126e551 #8 [ffff88011b9d5dd0] kobject_uevent at ffffffff8126e9eb #9 [ffff88011b9d5de0] device_del at ffffffff813440c7 -------------------8<--------------------------------------- So clean up when we have all the context, and all that's left to do when the references to the port have dropped is to free up the port struct itself. CC: <stable@vger.kernel.org> Reported-by: chayang <chayang@redhat.com> Reported-by: YOGANANTH SUBRAMANIAN <anantyog@in.ibm.com> Reported-by: FuXiangChun <xfu@redhat.com> Reported-by: Qunfang Zhang <qzhang@redhat.com> Reported-by: Sibiao Luo <sluo@redhat.com> Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-07-29 14:20:29 +09:30
virtio: console: clean up port data immediately at time of unplug We used to keep the port's char device structs and the /sys entries around till the last reference to the port was dropped. This is actually unnecessary, and resulted in buggy behaviour: 1. Open port in guest 2. Hot-unplug port 3. Hot-plug a port with the same 'name' property as the unplugged one This resulted in hot-plug being unsuccessful, as a port with the same name already exists (even though it was unplugged). This behaviour resulted in a warning message like this one: -------------------8<--------------------------------------- WARNING: at fs/sysfs/dir.c:512 sysfs_add_one+0xc9/0x130() (Not tainted) Hardware name: KVM sysfs: cannot create duplicate filename '/devices/pci0000:00/0000:00:04.0/virtio0/virtio-ports/vport0p1' Call Trace: [<ffffffff8106b607>] ? warn_slowpath_common+0x87/0xc0 [<ffffffff8106b6f6>] ? warn_slowpath_fmt+0x46/0x50 [<ffffffff811f2319>] ? sysfs_add_one+0xc9/0x130 [<ffffffff811f23e8>] ? create_dir+0x68/0xb0 [<ffffffff811f2469>] ? sysfs_create_dir+0x39/0x50 [<ffffffff81273129>] ? kobject_add_internal+0xb9/0x260 [<ffffffff812733d8>] ? kobject_add_varg+0x38/0x60 [<ffffffff812734b4>] ? kobject_add+0x44/0x70 [<ffffffff81349de4>] ? get_device_parent+0xf4/0x1d0 [<ffffffff8134b389>] ? device_add+0xc9/0x650 -------------------8<--------------------------------------- Instead of relying on guest applications to release all references to the ports, we should go ahead and unregister the port from all the core layers. Any open/read calls on the port will then just return errors, and an unplug/plug operation on the host will succeed as expected. This also caused buggy behaviour in case of the device removal (not just a port): when the device was removed (which means all ports on that device are removed automatically as well), the ports with active users would clean up only when the last references were dropped -- and it would be too late then to be referencing char device pointers, resulting in oopses: -------------------8<--------------------------------------- PID: 6162 TASK: ffff8801147ad500 CPU: 0 COMMAND: "cat" #0 [ffff88011b9d5a90] machine_kexec at ffffffff8103232b #1 [ffff88011b9d5af0] crash_kexec at ffffffff810b9322 #2 [ffff88011b9d5bc0] oops_end at ffffffff814f4a50 #3 [ffff88011b9d5bf0] die at ffffffff8100f26b #4 [ffff88011b9d5c20] do_general_protection at ffffffff814f45e2 #5 [ffff88011b9d5c50] general_protection at ffffffff814f3db5 [exception RIP: strlen+2] RIP: ffffffff81272ae2 RSP: ffff88011b9d5d00 RFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff880118901c18 RCX: 0000000000000000 RDX: ffff88011799982c RSI: 00000000000000d0 RDI: 3a303030302f3030 RBP: ffff88011b9d5d38 R8: 0000000000000006 R9: ffffffffa0134500 R10: 0000000000001000 R11: 0000000000001000 R12: ffff880117a1cc10 R13: 00000000000000d0 R14: 0000000000000017 R15: ffffffff81aff700 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #6 [ffff88011b9d5d00] kobject_get_path at ffffffff8126dc5d #7 [ffff88011b9d5d40] kobject_uevent_env at ffffffff8126e551 #8 [ffff88011b9d5dd0] kobject_uevent at ffffffff8126e9eb #9 [ffff88011b9d5de0] device_del at ffffffff813440c7 -------------------8<--------------------------------------- So clean up when we have all the context, and all that's left to do when the references to the port have dropped is to free up the port struct itself. CC: <stable@vger.kernel.org> Reported-by: chayang <chayang@redhat.com> Reported-by: YOGANANTH SUBRAMANIAN <anantyog@in.ibm.com> Reported-by: FuXiangChun <xfu@redhat.com> Reported-by: Qunfang Zhang <qzhang@redhat.com> Reported-by: Sibiao Luo <sluo@redhat.com> Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-07-29 14:20:29 +09:30