linux/drivers/char, branch v3.4.61

virtio: console: return -ENODEV on all read operations after unplug

2013-08-15T05:57:07Z

commit 96f97a83910cdb9d89d127c5ee523f8fc040a804 upstream. If a port gets unplugged while a user is blocked on read(), -ENODEV is returned. However, subsequent read()s returned 0, indicating there's no host-side connection (but not indicating the device went away). This also happened when a port was unplugged and the user didn't have any blocking operation pending. If the user didn't monitor the SIGIO signal, they won't have a chance to find out if the port went away. Fix by returning -ENODEV on all read()s after the port gets unplugged. write() already behaves this way. Signed-off-by: Amit Shah Signed-off-by: Rusty Russell Signed-off-by: Greg Kroah-Hartman

virtio: console: fix raising SIGIO after port unplug

2013-08-15T05:57:07Z

commit 92d3453815fbe74d539c86b60dab39ecdf01bb99 upstream. SIGIO should be sent when a port gets unplugged. It should only be sent to prcesses that have the port opened, and have asked for SIGIO to be delivered. We were clearing out guest_connected before calling send_sigio_to_port(), resulting in a sigio not getting sent to processes. Fix by setting guest_connected to false after invoking the sigio function. Signed-off-by: Amit Shah Signed-off-by: Rusty Russell Signed-off-by: Greg Kroah-Hartman

virtio: console: clean up port data immediately at time of unplug

2013-08-15T05:57:06Z

commit ea3768b4386a8d1790f4cc9a35de4f55b92d6442 upstream. 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: [] ? warn_slowpath_common+0x87/0xc0 [] ? warn_slowpath_fmt+0x46/0x50 [] ? sysfs_add_one+0xc9/0x130 [] ? create_dir+0x68/0xb0 [] ? sysfs_create_dir+0x39/0x50 [] ? kobject_add_internal+0xb9/0x260 [] ? kobject_add_varg+0x38/0x60 [] ? kobject_add+0x44/0x70 [] ? get_device_parent+0xf4/0x1d0 [] ? 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. Reported-by: chayang Reported-by: YOGANANTH SUBRAMANIAN Reported-by: FuXiangChun Reported-by: Qunfang Zhang Reported-by: Sibiao Luo Signed-off-by: Amit Shah Signed-off-by: Rusty Russell Signed-off-by: Greg Kroah-Hartman

virtio: console: fix race in port_fops_open() and port unplug

2013-08-15T05:57:06Z

commit 671bdea2b9f210566610603ecbb6584c8a201c8c upstream. Between open() being called and processed, the port can be unplugged. Check if this happened, and bail out. A simple test script to reproduce this is: while true; do for i in $(seq 1 100); do echo $i > /dev/vport0p3; done; done; This opens and closes the port a lot of times; unplugging the port while this is happening triggers the bug. Signed-off-by: Amit Shah Signed-off-by: Rusty Russell Signed-off-by: Greg Kroah-Hartman

virtio: console: fix race with port unplug and open/close

2013-08-15T05:57:06Z

commit 057b82be3ca3d066478e43b162fc082930a746c9 upstream. There's a window between find_port_by_devt() returning a port and us taking a kref on the port, where the port could get unplugged. Fix it by taking the reference in find_port_by_devt() itself. Problem reported and analyzed by Mateusz Guzik. Reported-by: Mateusz Guzik Signed-off-by: Amit Shah Signed-off-by: Rusty Russell Signed-off-by: Greg Kroah-Hartman

ipmi: ipmi_devintf: compat_ioctl method fails to take ipmi_mutex

2013-05-19T17:54:49Z

commit 6368087e851e697679af059b4247aca33a69cef3 upstream. When a 32 bit version of ipmitool is used on a 64 bit kernel, the ipmi_devintf code fails to correctly acquire ipmi_mutex. This results in incomplete data being retrieved in some cases, or other possible failures. Add a wrapper around compat_ipmi_ioctl() to take ipmi_mutex to fix this. Signed-off-by: Benjamin LaHaise Signed-off-by: Corey Minyard Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

drivers/char/ipmi: memcpy, need additional 2 bytes to avoid memory overflow

2013-05-19T17:54:49Z

commit a5f2b3d6a738e7d4180012fe7b541172f8c8dcea upstream. When calling memcpy, read_data and write_data need additional 2 bytes. write_data: for checking: "if (size > IPMI_MAX_MSG_LENGTH)" for operating: "memcpy(bt->write_data + 3, data + 1, size - 1)" read_data: for checking: "if (msg_len < 3 || msg_len > IPMI_MAX_MSG_LENGTH)" for operating: "memcpy(data + 2, bt->read_data + 4, msg_len - 2)" Signed-off-by: Chen Gang Signed-off-by: Corey Minyard Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

vm: convert HPET mmap to vm_iomap_memory() helper

2013-04-26T04:19:56Z

commit 2323036dfec8ce3ce6e1c86a49a31b039f3300d1 upstream. This is my example conversion of a few existing mmap users. The HPET case is simple, widely available, and easy to test (Clemens Ladisch sent a trivial test-program for it). Test-program-by: Clemens Ladisch Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

virtio: rng: disallow multiple device registrations, fixes crashes

2013-03-20T20:04:57Z

commit e84e7a56a3aa2963db506299e29a5f3f09377f9b upstream. The code currently only supports one virtio-rng device at a time. Invoking guests with multiple devices causes the guest to blow up. Check if we've already registered and initialised the driver. Also cleanup in case of registration errors or hot-unplug so that a new device can be used. Reported-by: Peter Krempa Reported-by: Signed-off-by: Amit Shah Signed-off-by: Rusty Russell Signed-off-by: Greg Kroah-Hartman

hw_random: make buffer usable in scatterlist.

2013-03-14T18:29:42Z

commit f7f154f1246ccc5a0a7e9ce50932627d60a0c878 upstream. virtio_rng feeds the randomness buffer handed by the core directly into the scatterlist, since commit bb347d98079a547e80bd4722dee1de61e4dca0e8. However, if CONFIG_HW_RANDOM=m, the static buffer isn't a linear address (at least on most archs). We could fix this in virtio_rng, but it's actually far easier to just do it in the core as virtio_rng would have to allocate a buffer every time (it doesn't know how much the core will want to read). Reported-by: Aurelien Jarno Tested-by: Aurelien Jarno Signed-off-by: Rusty Russell Signed-off-by: Greg Kroah-Hartman