- 25 Feb, 2016 40 commits
-
-
Alexey Kardashevskiy authored
commit 6ecad912 upstream. Quite often drivers set only "write" permission assuming that this includes "read" permission as well and this works on plenty of platforms. However IODA2 is strict about this and produces an EEH when "read" permission is not set and reading happens. This adds a workaround in the IODA code to always add the "read" bit when the "write" bit is set. Fixes: 10b35b2b ("powerpc/powernv: Do not set "read" flag if direction==DMA_NONE") Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by:
Alexey Kardashevskiy <aik@ozlabs.ru> Tested-by:
Douglas Miller <dougmill@linux.vnet.ibm.com> Signed-off-by:
Michael Ellerman <mpe@ellerman.id.au> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Gavin Shan authored
commit 1bc74f1c upstream. When PCI bus is unplugged during full hotplug for EEH recovery, the platform PE instance (struct pnv_ioda_pe) isn't released and it dereferences the stale PCI bus that has been released. It leads to kernel crash when referring to the stale PCI bus. This fixes the issue by correcting the PE's primary bus when it's oneline at plugging time, in pnv_pci_dma_bus_setup() which is to be called by pcibios_fixup_bus(). Reported-by:
Andrew Donnellan <andrew.donnellan@au1.ibm.com> Reported-by:
Pradipta Ghosh <pradghos@in.ibm.com> Signed-off-by:
Gavin Shan <gwshan@linux.vnet.ibm.com> Tested-by:
-
Gavin Shan authored
commit 05ba75f8 upstream. When PE is created, its primary bus is cached to pe->bus. At later point, the cached primary bus is returned from eeh_pe_bus_get(). However, we could get stale cached primary bus and run into kernel crash in one case: full hotplug as part of fenced PHB error recovery releases all PCI busses under the PHB at unplugging time and recreate them at plugging time. pe->bus is still dereferencing the PCI bus that was released. This adds another PE flag (EEH_PE_PRI_BUS) to represent the validity of pe->bus. pe->bus is updated when its first child EEH device is online and the flag is set. Before unplugging in full hotplug for error recovery, the flag is cleared. Fixes: 8cdb2833 ("powerpc/eeh: Trace PCI bus from PE") Reported-by:
-
Gavin Shan authored
commit 7e56f627 upstream. In eeh_pe_loc_get(), the PE location code is retrieved from the "ibm,loc-code" property of the device node for the bridge of the PE's primary bus. It's not correct because the property indicates the parent PE's location code. This reads the correct PE location code from "ibm,io-base-loc-code" or "ibm,slot-location-code" property of PE parent bus's device node. Fixes: 357b2f3d ("powerpc/eeh: Dump PE location code") Signed-off-by:
Russell Currey <ruscur@russell.cc> Signed-off-by:
-
Trond Myklebust authored
commit 13331a55 upstream. We're seeing hangs in the NFS client code, with loops of the form: RPC: 30317 xmit incomplete (267368 left of 524448) RPC: 30317 call_status (status -11) RPC: 30317 call_transmit (status 0) RPC: 30317 xprt_prepare_transmit RPC: 30317 xprt_transmit(524448) RPC: xs_tcp_send_request(267368) = -11 RPC: 30317 xmit incomplete (267368 left of 524448) RPC: 30317 call_status (status -11) RPC: 30317 call_transmit (status 0) RPC: 30317 xprt_prepare_transmit RPC: 30317 xprt_transmit(524448) Turns out commit ceb5d58b ("net: fix sock_wake_async() rcu protection") moved SOCKWQ_ASYNC_NOSPACE out of sock->flags and into sk->sk_wq->flags, however it never tried to fix up the code in net/sunrpc. The new idiom is to use the flags in the RCU protected struct socket_wq. While we're at it, clear out the now redundant places where we set/clear SOCKWQ_ASYNC_NOSPACE and SOCK_NOSPACE. In principle, sk_stream_wait_memory() is supposed to set these for us, so we only need to clear them in the particular case of our ->write_space() callback. Fixes: ceb5d58b ("net: fix sock_wake_async() rcu protection") Cc: Eric Dumazet <edumazet@google.com> Signed-off-by:
Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by:
-
Andrew Gabbasov authored
commit bb00c898 upstream. If a name contains at least some characters with Unicode values exceeding single byte, the CS0 output should have 2 bytes per character. And if other input characters have single byte Unicode values, then the single input byte is converted to 2 output bytes, and the length of output becomes larger than the length of input. And if the input name is long enough, the output length may exceed the allocated buffer length. All this means that conversion from UTF8 or NLS to CS0 requires checking of output length in order to stop when it exceeds the given output buffer size. [JK: Make code return -ENAMETOOLONG instead of silently truncating the name] Signed-off-by:
Andrew Gabbasov <andrew_gabbasov@mentor.com> Signed-off-by:
Jan Kara <jack@suse.cz> Signed-off-by:
-
Andrew Gabbasov authored
commit ad402b26 upstream. udf_CS0toUTF8 function stops the conversion when the output buffer length reaches UDF_NAME_LEN-2, which is correct maximum name length, but, when checking, it leaves the space for a single byte only, while multi-bytes output characters can take more space, causing buffer overflow. Similar error exists in udf_CS0toNLS function, that restricts the output length to UDF_NAME_LEN, while actual maximum allowed length is UDF_NAME_LEN-2. In these cases the output can override not only the current buffer length field, causing corruption of the name buffer itself, but also following allocation structures, causing kernel crash. Adjust the output length checks in both functions to prevent buffer overruns in case of multi-bytes UTF8 or NLS characters. Signed-off-by:
-
Vegard Nossum authored
commit b0918d9f upstream. udf_next_aext() just follows extent pointers while extents are marked as indirect. This can loop forever for corrupted filesystem. Limit number the of indirect extents we are willing to follow in a row. [JK: Updated changelog, limit, style] Signed-off-by:
Vegard Nossum <vegard.nossum@oracle.com> Cc: Jan Kara <jack@suse.com> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
-
Trond Myklebust authored
commit 082fa37d upstream. We must not skip encoding the statistics, or the server will see an XDR encoding error. Signed-off-by:
-
Andrew Elble authored
commit 361cad3c upstream. We've seen this in a packet capture - I've intermixed what I think was going on. The fix here is to grab the so_lock sooner. 1964379 -> #1 open (for write) reply seqid=1 1964393 -> #2 open (for read) reply seqid=2 __nfs4_close(), state->n_wronly-- nfs4_state_set_mode_locked(), changes state->state = [R] state->flags is [RW] state->state is [R], state->n_wronly == 0, state->n_rdonly == 1 1964398 -> #3 open (for write) call -> because close is already running 1964399 -> downgrade (to read) call seqid=2 (close of #1) 1964402 -> #3 open (for write) reply seqid=3 __update_open_stateid() nfs_set_open_stateid_locked(), changes state->flags state->flags is [RW] state->state is [R], state->n_wronly == 0, state->n_rdonly == 1 new sequence number is exposed now via nfs4_stateid_copy() next step would be update_open_stateflags(), pending so_lock 1964403 -> downgrade reply seqid=2, fails with OLD_STATEID (close of #1) nfs4_close_prepare() gets so_lock and recalcs flags -> send close 1964405 -> downgrade (to read) call seqid=3 (close of #1 retry) __update_open_stateid() gets so_lock * update_open_stateflags() updates state->n_wronly. nfs4_state_set_mode_locked() updates state->state state->flags is [RW] state->state is [RW], state->n_wronly == 1, state->n_rdonly == 1 * should have suppressed the preceding nfs4_close_prepare() from sending open_downgrade 1964406 -> write call 1964408 -> downgrade (to read) reply seqid=4 (close of #1 retry) nfs_clear_open_stateid_locked() state->flags is [R] state->state is [RW], state->n_wronly == 1, state->n_rdonly == 1 1964409 -> write reply (fails, openmode) Signed-off-by:
Andrew Elble <aweits@rit.edu> Signed-off-by:
-
Trond Myklebust authored
commit 86fb449b upstream. Jeff reports seeing an Oops in ff_layout_alloc_lseg. Turns out copy+paste has played cruel tricks on a nested loop. Reported-by:
Jeff Layton <jeff.layton@primarydata.com> Signed-off-by:
-
Trond Myklebust authored
commit ade14a7d upstream. If a NFSv4 client uses the cache_consistency_bitmask in order to request only information about the change attribute, timestamps and size, then it has not revalidated all attributes, and hence the attribute timeout timestamp should not be updated. Reported-by:
Donald Buczek <buczek@molgen.mpg.de> Signed-off-by:
-
Anton Protopopov authored
commit 4b550af5 upstream. The setup_ntlmv2_rsp() function may return positive value ENOMEM instead of -ENOMEM in case of kmalloc failure. Signed-off-by:
Anton Protopopov <a.s.protopopov@gmail.com> Signed-off-by:
Steve French <smfrench@gmail.com> Signed-off-by:
-
Vasily Averin authored
commit 01b9b0b2 upstream. In some cases tmp_bug can be not filled in cifs_filldir and stay uninitialized, therefore its printk with "%s" modifier can leak content of kernelspace memory. If old content of this buffer does not contain '\0' access bejond end of allocated object can crash the host. Signed-off-by:
Vasily Averin <vvs@virtuozzo.com> Signed-off-by:
Steve French <sfrench@localhost.localdomain> Signed-off-by:
-
Rabin Vincent authored
commit 820962dc upstream. cifs_call_async() queues the MID to the pending list and calls smb_send_rqst(). If smb_send_rqst() performs a partial send, it sets the tcpStatus to CifsNeedReconnect and returns an error code to cifs_call_async(). In this case, cifs_call_async() removes the MID from the list and returns to the caller. However, cifs_call_async() releases the server mutex _before_ removing the MID. This means that a cifs_reconnect() can race with this function and manage to remove the MID from the list and delete the entry before cifs_call_async() calls cifs_delete_mid(). This leads to various crashes due to the use after free in cifs_delete_mid(). Task1 Task2 cifs_call_async(): - rc = -EAGAIN - mutex_unlock(srv_mutex) cifs_reconnect(): - mutex_lock(srv_mutex) - mutex_unlock(srv_mutex) - list_delete(mid) - mid->callback() cifs_writev_callback(): - mutex_lock(srv_mutex) - delete(mid) - mutex_unlock(srv_mutex) - cifs_delete_mid(mid) <---- use after free Fix this by removing the MID in cifs_call_async() before releasing the srv_mutex. Also hold the srv_mutex in cifs_reconnect() until the MIDs are moved out of the pending list. Signed-off-by:
Rabin Vincent <rabin.vincent@axis.com> Acked-by:
Shirish Pargaonkar <shirishpargaonkar@gmail.com> Signed-off-by:
-
Jamie Bainbridge authored
commit ec7147a9 upstream. Under some conditions, CIFS can repeatedly call the cifs_dbg() logging wrapper. If done rapidly enough, the console framebuffer can softlockup or "rcu_sched self-detected stall". Apply the built-in log ratelimiters to prevent such hangs. Signed-off-by:
Jamie Bainbridge <jamie.bainbridge@gmail.com> Signed-off-by:
-
Dan Carpenter authored
commit d81dac3c upstream. In twl4030_bci_probe() there are some failure paths where we call iio_channel_release() with a NULL pointer. (Apparently, that driver can opperate without a valid channel pointer). Let's fix it by adding a NULL check in iio_channel_release(). Fixes: 2202e1fc ('drivers: power: twl4030_charger: fix link problems when building as module') Signed-off-by:
Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by:
Jonathan Cameron <jic23@kernel.org> Signed-off-by:
-
Akinobu Mita authored
commit 431386e7 upstream. According to the datasheet, the resolusion of temperature sensor is -5.35 counts/C. Temperature ADC is 472 counts at 25C. (https://www.sparkfun.com/datasheets/Sensors/Pressure/MPL115A1.pdf NOTE: This is older revision, but this information is removed from the latest datasheet from nxp somehow) Temp [C] = (Tadc - 472) / -5.35 + 25 = (Tadc - 605.750000) * -0.186915888 So the correct offset is -605.750000. Signed-off-by:
Akinobu Mita <akinobu.mita@gmail.com> Acked-by:
Peter Meerwald-Stadler <pmeerw@pmeerw.net> Signed-off-by:
-
Gabriele Mazzotta authored
commit fa34e6dd upstream. As per the ACPI specification (Revision 5.0) [1], the data coming from the sensor represent the ambient light illuminance reading expressed in lux. So use IIO_CHAN_INFO_PROCESSED to signify that the data are pre-processed. However, to keep backward ABI compatibility, the IIO_CHAN_INFO_RAW bit is not removed. [1] http://www.acpi.info/DOWNLOADS/ACPIspec50.pdf This issue has also been responsible for at least one userspace bug report hence marking what is a small semantic fix really for stable. [2] https://github.com/hadess/iio-sensor-proxy/issues/46Signed-off-by:
Gabriele Mazzotta <gabriele.mzt@gmail.com> Signed-off-by:
-
Yong Li authored
commit 97a249e9 upstream. Without this change, the name entity for mcp4725 is missing in /sys/bus/iio/devices/iio\:device*/name With this change, name is reported correctly Signed-off-by:
Yong Li <sdliyong@gmail.com> Signed-off-by:
-
Vegard Nossum authored
commit 01cc5235 upstream. Ran into this on UML: drivers/iio/accel/stk8ba50.c: In function ‘stk8ba50_data_rdy_trigger_set_state’: drivers/iio/accel/stk8ba50.c:163:9: error: implicit declaration of function ‘iio_trigger_get_drvdata’ [-Werror=implicit-function-declaration] iio_trigger_get_drvdata() is defined only when IIO_TRIGGER is selected. Signed-off-by:
-
Vegard Nossum authored
commit 005ce071 upstream. Ran into this on UML: drivers/built-in.o: In function `vf610_adc_probe': drivers/iio/adc/vf610_adc.c:744: undefined reference to `devm_ioremap_resource' devm_ioremap_resource() is defined only when HAS_IOMEM is selected. Signed-off-by:
-
Markus Elfring authored
commit c08ae185 upstream. The return type "unsigned int" was used by the ltr501_match_samp_freq() function despite of the aspect that it will eventually return a negative error code. Improve this implementation detail by deletion of the type modifier then. This issue was detected by using the Coccinelle software. Signed-off-by:
Markus Elfring <elfring@users.sourceforge.net> Acked-by:
-
Jonathan Cameron authored
commit 9d0be85d upstream. Whilst this part has a hardware buffer, the identifcation that IIO cares about is the userspace facing end. It this case we push individual elements from the hardware fifo into the software interface (specifically a kfifo) rather than providing direct reads through to a hardware buffer (as we still do in the sca3000 for example). Technically the original specification as a hardware buffer could be considered wrong, but it didn't matter until the patch listed below. Result is that any attempt to enable the buffer will return -EINVAL Fixes: 225d59ad ("iio: Specify supported modes for buffers") Signed-off-by:
-
Lars-Peter Clausen authored
commit d590faf9 upstream. The SPI tx and rx buffers are both supposed to be scan_bytes amount of bytes large and a common allocation is used to allocate both buffers. This puts the beginning of the tx buffer scan_bytes bytes after the rx buffer. The initialization of the tx buffer pointer is done adding scan_bytes to the beginning of the rx buffer, but since the rx buffer is of type __be16 this will actually add two times as much and the tx buffer ends up pointing after the allocated buffer. Fix this by using scan_count, which is scan_bytes / 2, instead of scan_bytes when initializing the tx buffer pointer. Fixes: aacff892 ("staging:iio:adis: Preallocate transfer message") Signed-off-by:
Lars-Peter Clausen <lars@metafoo.de> Signed-off-by:
-
James Bottomley authored
commit 90a88d6e upstream. This softlockup is currently happening: [ 444.088002] NMI watchdog: BUG: soft lockup - CPU#1 stuck for 22s! [kworker/1:1:29] [ 444.088002] Modules linked in: lpfc(-) qla2x00tgt(O) qla2xxx_scst(O) scst_vdisk(O) scsi_transport_fc libcrc32c scst(O) dlm configfs nfsd lockd grace nfs_acl auth_rpcgss sunrpc ed d snd_pcm_oss snd_mixer_oss snd_seq snd_seq_device dm_mod iTCO_wdt snd_hda_codec_realtek snd_hda_codec_generic gpio_ich iTCO_vendor_support ppdev snd_hda_intel snd_hda_codec snd_hda _core snd_hwdep tg3 snd_pcm snd_timer libphy lpc_ich parport_pc ptp acpi_cpufreq snd pps_core fjes parport i2c_i801 ehci_pci tpm_tis tpm sr_mod cdrom soundcore floppy hwmon sg 8250_ fintek pcspkr i915 drm_kms_helper uhci_hcd ehci_hcd drm fb_sys_fops sysimgblt sysfillrect syscopyarea i2c_algo_bit usbcore button video usb_common fan ata_generic ata_piix libata th ermal [ 444.088002] CPU: 1 PID: 29 Comm: kworker/1:1 Tainted: G O 4.4.0-rc5-2.g1e923a3-default #1 [ 444.088002] Hardware name: FUJITSU SIEMENS ESPRIMO E /D2164-A1, BIOS 5.00 R1.10.2164.A1 05/08/2006 [ 444.088002] Workqueue: fc_wq_4 fc_rport_final_delete [scsi_transport_fc] [ 444.088002] task: f6266ec0 ti: f6268000 task.ti: f6268000 [ 444.088002] EIP: 0060:[<c07e7044>] EFLAGS: 00000286 CPU: 1 [ 444.088002] EIP is at _raw_spin_unlock_irqrestore+0x14/0x20 [ 444.088002] EAX: 00000286 EBX: f20d3800 ECX: 00000002 EDX: 00000286 [ 444.088002] ESI: f50ba800 EDI: f2146848 EBP: f6269ec8 ESP: f6269ec8 [ 444.088002] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 [ 444.088002] CR0: 8005003b CR2: 08f96600 CR3: 363ae000 CR4: 000006d0 [ 444.088002] Stack: [ 444.088002] f6269eec c066b0f7 00000286 f2146848 f50ba808 f50ba800 f50ba800 f2146a90 [ 444.088002] f2146848 f6269f08 f8f0a4ed f3141000 f2146800 f2146a90 f619fa00 00000040 [ 444.088002] f6269f40 c026cb25 00000001 166c6392 00000061 f6757140 f6136340 00000004 [ 444.088002] Call Trace: [ 444.088002] [<c066b0f7>] scsi_remove_target+0x167/0x1c0 [ 444.088002] [<f8f0a4ed>] fc_rport_final_delete+0x9d/0x1e0 [scsi_transport_fc] [ 444.088002] [<c026cb25>] process_one_work+0x155/0x3e0 [ 444.088002] [<c026cde7>] worker_thread+0x37/0x490 [ 444.088002] [<c027214b>] kthread+0x9b/0xb0 [ 444.088002] [<c07e72c1>] ret_from_kernel_thread+0x21/0x40 What appears to be happening is that something has pinned the target so it can't go into STARGET_DEL via final release and the loop in scsi_remove_target spins endlessly until that happens. The fix for this soft lockup is to not keep looping over a device that we've called remove on but which hasn't gone into DEL state. This patch will retain a simplistic memory of the last target and not keep looping over it. Reported-by:
Sebastian Herbszt <herbszt@gmx.de> Tested-by:
James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by:
-
Mika Westerberg authored
commit 82c43310 upstream. I have a Marvell 88SE9230 SATA Controller that has some sort of integrated console SCSI device attached to one of the ports. ata14: SATA link up 1.5 Gbps (SStatus 113 SControl 300) ata14.00: ATAPI: MARVELL VIRTUALL, 1.09, max UDMA/66 ata14.00: configured for UDMA/66 scsi 13:0:0:0: Processor Marvell Console 1.01 PQ: 0 ANSI: 5 Sending it VPD INQUIRY command seem to always fail with following error: ata14.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 ata14.00: irq_stat 0x40000001 ata14.00: cmd a0/01:00:00:00:01/00:00:00:00:00/a0 tag 2 dma 16640 in Inquiry 12 01 00 00 ff 00res 00/00:00:00:00:00/00:00:00:00:00/00 Emask 0x3 (HSM violation) ata14: hard resetting link This has been minor annoyance (only error printed on dmesg) until commit 09e2b0b1 ("scsi: rescan VPD attributes") added call to scsi_attach_vpd() in scsi_rescan_device(). The commit causes the system to splat out following errors continuously without ever reaching the UI: ata14.00: configured for UDMA/66 ata14: EH complete ata14.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 ata14.00: irq_stat 0x40000001 ata14.00: cmd a0/01:00:00:00:01/00:00:00:00:00/a0 tag 6 dma 16640 in Inquiry 12 01 00 00 ff 00res 00/00:00:00:00:00/00:00:00:00:00/00 Emask 0x3 (HSM violation) ata14: hard resetting link ata14: SATA link up 1.5 Gbps (SStatus 113 SControl 300) ata14.00: configured for UDMA/66 ata14: EH complete ata14.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 ata14.00: irq_stat 0x40000001 ata14.00: cmd a0/01:00:00:00:01/00:00:00:00:00/a0 tag 7 dma 16640 in Inquiry 12 01 00 00 ff 00res 00/00:00:00:00:00/00:00:00:00:00/00 Emask 0x3 (HSM violation) Without in-depth understanding of SCSI layer and the Marvell controller, I suspect this happens because when the link goes down (because of an error) we schedule scsi_rescan_device() which again fails to read VPD data... ad infinitum. Since VPD data cannot be read from the device anyway we prevent the SCSI layer from even trying by blacklisting the device. This gets away the error and the system starts up normally. [mkp: Widened the match to all revisions of this device] Signed-off-by:
Mika Westerberg <mika.westerberg@linux.intel.com> Reported-by:
Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by:
Alexander Duyck <alexander.duyck@gmail.com> Signed-off-by:
Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by:
-
Hannes Reinecke authored
commit d2d06d4f upstream. If MODE SELECT returns with sense '05/91/36' (command lock violation) it should always be retried without counting the number of retries. During an HBA upgrade or similar circumstances one might see a flood of MODE SELECT command from various HBAs, which will easily trigger the sense code and exceed the retry count. Signed-off-by:
Hannes Reinecke <hare@suse.de> Reviewed-by:
Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by:
-
Kirill A. Shutemov authored
commit 461c7fa1 upstream. Reduced testcase: #include <fcntl.h> #include <unistd.h> #include <sys/mman.h> #include <numaif.h> #define SIZE 0x2000 int main() { int fd; void *p; fd = open("/dev/sg0", O_RDWR); p = mmap(NULL, SIZE, PROT_EXEC, MAP_PRIVATE | MAP_LOCKED, fd, 0); mbind(p, SIZE, 0, NULL, 0, MPOL_MF_MOVE); return 0; } We shouldn't try to migrate pages in sg VMA as we don't have a way to update Sg_scatter_hold::pages accordingly from mm core. Let's mark the VMA as VM_IO to indicate to mm core that the VMA is not migratable. Signed-off-by:
Dmitry Vyukov <dvyukov@google.com> Acked-by:
Vlastimil Babka <vbabka@suse.cz> Cc: Doug Gilbert <dgilbert@interlog.com> Cc: David Rientjes <rientjes@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Shiraz Hashim <shashim@codeaurora.org> Cc: Hugh Dickins <hughd@google.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: syzkaller <syzkaller@googlegroups.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
-
Alan Stern authored
commit 13b43891 upstream. Runtime suspend during driver probe and removal can cause problems. The driver's runtime_suspend or runtime_resume callbacks may invoked before the driver has finished binding to the device or after the driver has unbound from the device. This problem shows up with the sd and sr drivers, and can cause disk or CD/DVD drives to become unusable as a result. The fix is simple. The drivers store a pointer to the scsi_disk or scsi_cd structure as their private device data when probing is finished, so we simply have to be sure to clear the private data during removal and test it during runtime suspend/resume. This fixes <https://bugs.debian.org/801925>. Signed-off-by:
Alan Stern <stern@rowland.harvard.edu> Reported-by:
Paul Menzel <paul.menzel@giantmonkey.de> Reported-by:
Erich Schubert <erich@debian.org> Reported-by:
Alexandre Rossi <alexandre.rossi@gmail.com> Tested-by:
-
Nicholas Bellinger authored
commit 26a99c19 upstream. This patch is a iscsi-target specific bug-fix for a dead-lock that can occur during explicit struct se_node_acl->acl_group se_session deletion via configfs rmdir(2), when iscsi-target time2retain timer is still active. It changes iscsi-target to obtain se_portal_group->session_lock internally using spin_in_locked() to check for the specific se_node_acl configfs shutdown rmdir(2) case. Note this patch is intended for stable, and the subsequent v4.5-rc patch converts target_core_tpg.c to use proper se_sess->sess_kref reference counting for both se_node_acl deletion + se_node_acl->queue_depth se_session restart. Reported-by:
: Sagi Grimberg <sagig@mellanox.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.de> Cc: Andy Grover <agrover@redhat.com> Cc: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by:
Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by:
-
Mike Christie authored
commit 9055082f upstream. Another iscsi target that cannot handle large IOs, but does not tell us a limit. The Synology iSCSI targets report: Block limits VPD page (SBC): Write same no zero (WSNZ): 0 Maximum compare and write length: 0 blocks Optimal transfer length granularity: 0 blocks Maximum transfer length: 0 blocks Optimal transfer length: 0 blocks Maximum prefetch length: 0 blocks Maximum unmap LBA count: 0 Maximum unmap block descriptor count: 0 Optimal unmap granularity: 0 Unmap granularity alignment valid: 0 Unmap granularity alignment: 0 Maximum write same length: 0x0 blocks and the size of the command it can handle seems to depend on how much memory it can allocate at the time. This results in IO errors when handling large IOs. This patch just has us use the old 1024 default sectors for this target by adding it to the scsi blacklist. We do not have good contacs with this vendors, so I have not been able to try and fix on their side. I have posted this a long while back, but it was not merged. This version just fixes it up for merge/patch failures in the original version. Reported-by:
Ancoron Luciferis <ancoron.luciferis@googlemail.com> Reported-by:
Michael Meyers <steltek@tcnnet.com> Signed-off-by:
Mike Christie <mchristi@redhat.com> Signed-off-by:
-
James Bottomley authored
commit 00cd29b7 upstream. The starting node for a klist iteration is often passed in from somewhere way above the klist infrastructure, meaning there's no guarantee the node is still on the list. We've seen this in SCSI where we use bus_find_device() to iterate through a list of devices. In the face of heavy hotplug activity, the last device returned by bus_find_device() can be removed before the next call. This leads to Dec 3 13:22:02 localhost kernel: WARNING: CPU: 2 PID: 28073 at include/linux/kref.h:47 klist_iter_init_node+0x3d/0x50() Dec 3 13:22:02 localhost kernel: Modules linked in: scsi_debug x86_pkg_temp_thermal kvm_intel kvm irqbypass crc32c_intel joydev iTCO_wdt dcdbas ipmi_devintf acpi_power_meter iTCO_vendor_support ipmi_si imsghandler pcspkr wmi acpi_cpufreq tpm_tis tpm shpchp lpc_ich mfd_core nfsd nfs_acl lockd grace sunrpc tg3 ptp pps_core Dec 3 13:22:02 localhost kernel: CPU: 2 PID: 28073 Comm: cat Not tainted 4.4.0-rc1+ #2 Dec 3 13:22:02 localhost kernel: Hardware name: Dell Inc. PowerEdge R320/08VT7V, BIOS 2.0.22 11/19/2013 Dec 3 13:22:02 localhost kernel: ffffffff81a20e77 ffff880613acfd18 ffffffff81321eef 0000000000000000 Dec 3 13:22:02 localhost kernel: ffff880613acfd50 ffffffff8107ca52 ffff88061176b198 0000000000000000 Dec 3 13:22:02 localhost kernel: ffffffff814542b0 ffff880610cfb100 ffff88061176b198 ffff880613acfd60 Dec 3 13:22:02 localhost kernel: Call Trace: Dec 3 13:22:02 localhost kernel: [<ffffffff81321eef>] dump_stack+0x44/0x55 Dec 3 13:22:02 localhost kernel: [<ffffffff8107ca52>] warn_slowpath_common+0x82/0xc0 Dec 3 13:22:02 localhost kernel: [<ffffffff814542b0>] ? proc_scsi_show+0x20/0x20 Dec 3 13:22:02 localhost kernel: [<ffffffff8107cb4a>] warn_slowpath_null+0x1a/0x20 Dec 3 13:22:02 localhost kernel: [<ffffffff8167225d>] klist_iter_init_node+0x3d/0x50 Dec 3 13:22:02 localhost kernel: [<ffffffff81421d41>] bus_find_device+0x51/0xb0 Dec 3 13:22:02 localhost kernel: [<ffffffff814545ad>] scsi_seq_next+0x2d/0x40 [...] And an eventual crash. It can actually occur in any hotplug system which has a device finder and a starting device. We can fix this globally by making sure the starting node for klist_iter_init_node() is actually a member of the list before using it (and by starting from the beginning if it isn't). Reported-by:
Ewan D. Milne <emilne@redhat.com> Tested-by:
-
Steven Rostedt (Red Hat) authored
commit f3775549 upstream. The tracepoint infrastructure uses RCU sched protection to enable and disable tracepoints safely. There are some instances where tracepoints are used in infrastructure code (like kfree()) that get called after a CPU is going offline, and perhaps when it is coming back online but hasn't been registered yet. This can probuce the following warning: [ INFO: suspicious RCU usage. ] 4.4.0-00006-g0fe53e8-dirty #34 Tainted: G S ------------------------------- include/trace/events/kmem.h:141 suspicious rcu_dereference_check() usage! other info that might help us debug this: RCU used illegally from offline CPU! rcu_scheduler_active = 1, debug_locks = 1 no locks held by swapper/8/0. stack backtrace: CPU: 8 PID: 0 Comm: swapper/8 Tainted: G S 4.4.0-00006-g0fe53e8-dirty #34 Call Trace: [c0000005b76c78d0] [c0000000008b9540] .dump_stack+0x98/0xd4 (unreliable) [c0000005b76c7950] [c00000000010c898] .lockdep_rcu_suspicious+0x108/0x170 [c0000005b76c79e0] [c00000000029adc0] .kfree+0x390/0x440 [c0000005b76c7a80] [c000000000055f74] .destroy_context+0x44/0x100 [c0000005b76c7b00] [c0000000000934a0] .__mmdrop+0x60/0x150 [c0000005b76c7b90] [c0000000000e3ff0] .idle_task_exit+0x130/0x140 [c0000005b76c7c20] [c000000000075804] .pseries_mach_cpu_die+0x64/0x310 [c0000005b76c7cd0] [c000000000043e7c] .cpu_die+0x3c/0x60 [c0000005b76c7d40] [c0000000000188d8] .arch_cpu_idle_dead+0x28/0x40 [c0000005b76c7db0] [c000000000101e6c] .cpu_startup_entry+0x50c/0x560 [c0000005b76c7ed0] [c000000000043bd8] .start_secondary+0x328/0x360 [c0000005b76c7f90] [c000000000008a6c] start_secondary_prolog+0x10/0x14 This warning is not a false positive either. RCU is not protecting code that is being executed while the CPU is offline. Instead of playing "whack-a-mole(TM)" and adding conditional statements to the tracepoints we find that are used in this instance, simply add a cpu_online() test to the tracepoint code where the tracepoint will be ignored if the CPU is offline. Use of raw_smp_processor_id() is fine, as there should never be a case where the tracepoint code goes from running on a CPU that is online and suddenly gets migrated to a CPU that is offline. Link: http://lkml.kernel.org/r/1455387773-4245-1-git-send-email-kda@linux-powerpc.orgReported-by:
Denis Kirjanov <kda@linux-powerpc.org> Fixes: 97e1c18e ("tracing: Kernel Tracepoints") Signed-off-by:
Steven Rostedt <rostedt@goodmis.org> Signed-off-by:
-
Arnd Bergmann authored
commit b33c8ff4 upstream. In my randconfig tests, I came across a bug that involves several components: * gcc-4.9 through at least 5.3 * CONFIG_GCOV_PROFILE_ALL enabling -fprofile-arcs for all files * CONFIG_PROFILE_ALL_BRANCHES overriding every if() * The optimized implementation of do_div() that tries to replace a library call with an division by multiplication * code in drivers/media/dvb-frontends/zl10353.c doing u32 adc_clock = 450560; /* 45.056 MHz */ if (state->config.adc_clock) adc_clock = state->config.adc_clock; do_div(value, adc_clock); In this case, gcc fails to determine whether the divisor in do_div() is __builtin_constant_p(). In particular, it concludes that __builtin_constant_p(adc_clock) is false, while __builtin_constant_p(!!adc_clock) is true. That in turn throws off the logic in do_div() that also uses __builtin_constant_p(), and instead of picking either the constant- optimized division, and the code in ilog2() that uses __builtin_constant_p() to figure out whether it knows the answer at compile time. The result is a link error from failing to find multiple symbols that should never have been called based on the __builtin_constant_p(): dvb-frontends/zl10353.c:138: undefined reference to `____ilog2_NaN' dvb-frontends/zl10353.c:138: undefined reference to `__aeabi_uldivmod' ERROR: "____ilog2_NaN" [drivers/media/dvb-frontends/zl10353.ko] undefined! ERROR: "__aeabi_uldivmod" [drivers/media/dvb-frontends/zl10353.ko] undefined! This patch avoids the problem by changing __trace_if() to check whether the condition is known at compile-time to be nonzero, rather than checking whether it is actually a constant. I see this one link error in roughly one out of 1600 randconfig builds on ARM, and the patch fixes all known instances. Link: http://lkml.kernel.org/r/1455312410-1058841-1-git-send-email-arnd@arndb.deAcked-by:
Nicolas Pitre <nico@linaro.org> Fixes: ab3c9c68 ("branch tracer, intel-iommu: fix build with CONFIG_BRANCH_TRACER=y") Signed-off-by:
Arnd Bergmann <arnd@arndb.de> Signed-off-by:
-
Adrian Hunter authored
commit ec183d22 upstream. Fixes segmentation fault using, for instance: (gdb) run record -I -e intel_pt/tsc=1,noretcomp=1/u /bin/ls Starting program: /home/acme/bin/perf record -I -e intel_pt/tsc=1,noretcomp=1/u /bin/ls Missing separate debuginfos, use: dnf debuginfo-install glibc-2.22-7.fc23.x86_64 [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib64/libthread_db.so.1". Program received signal SIGSEGV, Segmentation fault. 0 x00000000004b9ea5 in tracepoint_error (e=0x0, err=13, sys=0x19b1370 "sched", name=0x19a5d00 "sched_switch") at util/parse-events.c:410 (gdb) bt #0 0x00000000004b9ea5 in tracepoint_error (e=0x0, err=13, sys=0x19b1370 "sched", name=0x19a5d00 "sched_switch") at util/parse-events.c:410 #1 0x00000000004b9fc5 in add_tracepoint (list=0x19a5d20, idx=0x7fffffffb8c0, sys_name=0x19b1370 "sched", evt_name=0x19a5d00 "sched_switch", err=0x0, head_config=0x0) at util/parse-events.c:433 #2 0x00000000004ba334 in add_tracepoint_event (list=0x19a5d20, idx=0x7fffffffb8c0, sys_name=0x19b1370 "sched", evt_name=0x19a5d00 "sched_switch", err=0x0, head_config=0x0) at util/parse-events.c:498 #3 0x00000000004bb699 in parse_events_add_tracepoint (list=0x19a5d20, idx=0x7fffffffb8c0, sys=0x19b1370 "sched", event=0x19a5d00 "sched_switch", err=0x0, head_config=0x0) at util/parse-events.c:936 #4 0x00000000004f6eda in parse_events_parse (_data=0x7fffffffb8b0, scanner=0x19a49d0) at util/parse-events.y:391 #5 0x00000000004bc8e5 in parse_events__scanner (str=0x663ff2 "sched:sched_switch", data=0x7fffffffb8b0, start_token=258) at util/parse-events.c:1361 #6 0x00000000004bca57 in parse_events (evlist=0x19a5220, str=0x663ff2 "sched:sched_switch", err=0x0) at util/parse-events.c:1401 #7 0x0000000000518d5f in perf_evlist__can_select_event (evlist=0x19a3b90, str=0x663ff2 "sched:sched_switch") at util/record.c:253 #8 0x0000000000553c42 in intel_pt_track_switches (evlist=0x19a3b90) at arch/x86/util/intel-pt.c:364 #9 0x00000000005549d1 in intel_pt_recording_options (itr=0x19a2c40, evlist=0x19a3b90, opts=0x8edf68 <record+232>) at arch/x86/util/intel-pt.c:664 #10 0x000000000051e076 in auxtrace_record__options (itr=0x19a2c40, evlist=0x19a3b90, opts=0x8edf68 <record+232>) at util/auxtrace.c:539 #11 0x0000000000433368 in cmd_record (argc=1, argv=0x7fffffffde60, prefix=0x0) at builtin-record.c:1264 #12 0x000000000049bec2 in run_builtin (p=0x8fa2a8 <commands+168>, argc=5, argv=0x7fffffffde60) at perf.c:390 #13 0x000000000049c12a in handle_internal_command (argc=5, argv=0x7fffffffde60) at perf.c:451 #14 0x000000000049c278 in run_argv (argcp=0x7fffffffdcbc, argv=0x7fffffffdcb0) at perf.c:495 #15 0x000000000049c60a in main (argc=5, argv=0x7fffffffde60) at perf.c:618 (gdb) Intel PT attempts to find the sched:sched_switch tracepoint but that seg faults if tracefs is not readable, because the error reporting structure is null, as errors are not reported when automatically adding tracepoints. Fix by checking before using. Committer note: This doesn't take place in a kernel that supports perf_event_attr.context_switch, that is the default way that will be used for tracking context switches, only in older kernels, like 4.2, in a machine with Intel PT (e.g. Broadwell) for non-priviledged users. Further info from a similar patch by Wang: The error is in tracepoint_error: it assumes the 'e' parameter is valid. However, there are many situation a parse_event() can be called without parse_events_error. See result of $ grep 'parse_events(.*NULL)' ./tools/perf/ -r' Signed-off-by:
Adrian Hunter <adrian.hunter@intel.com> Tested-by:
Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Tong Zhang <ztong@vt.edu> Cc: Wang Nan <wangnan0@huawei.com> Fixes: 19658171 ("perf tools: Enhance parsing events tracepoint error output") Link: http://lkml.kernel.org/r/1453809921-24596-2-git-send-email-adrian.hunter@intel.comSigned-off-by:
-
Steven Rostedt authored
commit 32abc2ed upstream. When a long value is read on 32 bit machines for 64 bit output, the parsing needs to change "%lu" into "%llu", as the value is read natively. Unfortunately, if "%llu" is already there, the code will add another "l" to it and fail to parse it properly. Signed-off-by:
Namhyung Kim <namhyung@kernel.org> Link: http://lkml.kernel.org/r/20151116172516.4b79b109@gandalf.local.homeSigned-off-by:
-
Jann Horn authored
commit caaee623 upstream. By checking the effective credentials instead of the real UID / permitted capabilities, ensure that the calling process actually intended to use its credentials. To ensure that all ptrace checks use the correct caller credentials (e.g. in case out-of-tree code or newly added code omits the PTRACE_MODE_*CREDS flag), use two new flags and require one of them to be set. The problem was that when a privileged task had temporarily dropped its privileges, e.g. by calling setreuid(0, user_uid), with the intent to perform following syscalls with the credentials of a user, it still passed ptrace access checks that the user would not be able to pass. While an attacker should not be able to convince the privileged task to perform a ptrace() syscall, this is a problem because the ptrace access check is reused for things in procfs. In particular, the following somewhat interesting procfs entries only rely on ptrace access checks: /proc/$pid/stat - uses the check for determining whether pointers should be visible, useful for bypassing ASLR /proc/$pid/maps - also useful for bypassing ASLR /proc/$pid/cwd - useful for gaining access to restricted directories that contain files with lax permissions, e.g. in this scenario: lrwxrwxrwx root root /proc/13020/cwd -> /root/foobar drwx------ root root /root drwxr-xr-x root root /root/foobar -rw-r--r-- root root /root/foobar/secret Therefore, on a system where a root-owned mode 6755 binary changes its effective credentials as described and then dumps a user-specified file, this could be used by an attacker to reveal the memory layout of root's processes or reveal the contents of files he is not allowed to access (through /proc/$pid/cwd). [akpm@linux-foundation.org: fix warning] Signed-off-by:
Jann Horn <jann@thejh.net> Acked-by:
Kees Cook <keescook@chromium.org> Cc: Casey Schaufler <casey@schaufler-ca.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Morris <james.l.morris@oracle.com> Cc: "Serge E. Hallyn" <serge.hallyn@ubuntu.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Willy Tarreau <w@1wt.eu> Signed-off-by:
-
Filipe Manana authored
commit 1636d1d7 upstream. If a bio for a direct IO request fails, we were not setting the error in the parent bio (the main DIO bio), making us not return the error to user space in btrfs_direct_IO(), that is, it made __blockdev_direct_IO() return the number of bytes issued for IO and not the error a bio created and submitted by btrfs_submit_direct() got from the block layer. This essentially happens because when we call: dio_end_io(dio_bio, bio->bi_error); It does not set dio_bio->bi_error to the value of the second argument. So just add this missing assignment in endio callbacks, just as we do in the error path at btrfs_submit_direct() when we fail to clone the dio bio or allocate its private object. This follows the convention of what is done with other similar APIs such as bio_endio() where the caller is responsible for setting the bi_error field in the bio it passes as an argument to bio_endio(). This was detected by the new generic test cases in xfstests: 271, 272, 276 and 278. Which essentially setup a dm error target, then load the error table, do a direct IO write and unload the error table. They expect the write to fail with -EIO, which was not getting reported when testing against btrfs. Fixes: 4246a0b6 ("block: add a bi_error field to struct bio") Signed-off-by:
Filipe Manana <fdmanana@suse.com> Signed-off-by:
-
Filipe Manana authored
commit 0c0fe3b0 upstream. While doing some tests I ran into an hang on an extent buffer's rwlock that produced the following trace: [39389.800012] NMI watchdog: BUG: soft lockup - CPU#15 stuck for 22s! [fdm-stress:32166] [39389.800016] NMI watchdog: BUG: soft lockup - CPU#14 stuck for 22s! [fdm-stress:32165] [39389.800016] Modules linked in: btrfs dm_mod ppdev xor sha256_generic hmac raid6_pq drbg ansi_cprng aesni_intel i2c_piix4 acpi_cpufreq aes_x86_64 ablk_helper tpm_tis parport_pc i2c_core sg cryptd evdev psmouse lrw tpm parport gf128mul serio_raw pcspkr glue_helper processor button loop autofs4 ext4 crc16 mbcache jbd2 sd_mod sr_mod cdrom ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring crc32c_intel scsi_mod e1000 virtio floppy [last unloaded: btrfs] [39389.800016] irq event stamp: 0 [39389.800016] hardirqs last enabled at (0): [< (null)>] (null) [39389.800016] hardirqs last disabled at (0): [<ffffffff8104e58d>] copy_process+0x638/0x1a35 [39389.800016] softirqs last enabled at (0): [<ffffffff8104e58d>] copy_process+0x638/0x1a35 [39389.800016] softirqs last disabled at (0): [< (null)>] (null) [39389.800016] CPU: 14 PID: 32165 Comm: fdm-stress Not tainted 4.4.0-rc6-btrfs-next-18+ #1 [39389.800016] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [39389.800016] task: ffff880175b1ca40 ti: ffff8800a185c000 task.ti: ffff8800a185c000 [39389.800016] RIP: 0010:[<ffffffff810902af>] [<ffffffff810902af>] queued_spin_lock_slowpath+0x57/0x158 [39389.800016] RSP: 0018:ffff8800a185fb80 EFLAGS: 00000202 [39389.800016] RAX: 0000000000000101 RBX: ffff8801710c4e9c RCX: 0000000000000101 [39389.800016] RDX: 0000000000000100 RSI: 0000000000000001 RDI: 0000000000000001 [39389.800016] RBP: ffff8800a185fb98 R08: 0000000000000001 R09: 0000000000000000 [39389.800016] R10: ffff8800a185fb68 R11: 6db6db6db6db6db7 R12: ffff8801710c4e98 [39389.800016] R13: ffff880175b1ca40 R14: ffff8800a185fc10 R15: ffff880175b1ca40 [39389.800016] FS: 00007f6d37fff700(0000) GS:ffff8802be9c0000(0000) knlGS:0000000000000000 [39389.800016] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [39389.800016] CR2: 00007f6d300019b8 CR3: 0000000037c93000 CR4: 00000000001406e0 [39389.800016] Stack: [39389.800016] ffff8801710c4e98 ffff8801710c4e98 ffff880175b1ca40 ffff8800a185fbb0 [39389.800016] ffffffff81091e11 ffff8801710c4e98 ffff8800a185fbc8 ffffffff81091895 [39389.800016] ffff8801710c4e98 ffff8800a185fbe8 ffffffff81486c5c ffffffffa067288c [39389.800016] Call Trace: [39389.800016] [<ffffffff81091e11>] queued_read_lock_slowpath+0x46/0x60 [39389.800016] [<ffffffff81091895>] do_raw_read_lock+0x3e/0x41 [39389.800016] [<ffffffff81486c5c>] _raw_read_lock+0x3d/0x44 [39389.800016] [<ffffffffa067288c>] ? btrfs_tree_read_lock+0x54/0x125 [btrfs] [39389.800016] [<ffffffffa067288c>] btrfs_tree_read_lock+0x54/0x125 [btrfs] [39389.800016] [<ffffffffa0622ced>] ? btrfs_find_item+0xa7/0xd2 [btrfs] [39389.800016] [<ffffffffa069363f>] btrfs_ref_to_path+0xd6/0x174 [btrfs] [39389.800016] [<ffffffffa0693730>] inode_to_path+0x53/0xa2 [btrfs] [39389.800016] [<ffffffffa0693e2e>] paths_from_inode+0x117/0x2ec [btrfs] [39389.800016] [<ffffffffa0670cff>] btrfs_ioctl+0xd5b/0x2793 [btrfs] [39389.800016] [<ffffffff8108a8b0>] ? arch_local_irq_save+0x9/0xc [39389.800016] [<ffffffff81276727>] ? __this_cpu_preempt_check+0x13/0x15 [39389.800016] [<ffffffff8108a8b0>] ? arch_local_irq_save+0x9/0xc [39389.800016] [<ffffffff8118b3d4>] ? rcu_read_unlock+0x3e/0x5d [39389.800016] [<ffffffff811822f8>] do_vfs_ioctl+0x42b/0x4ea [39389.800016] [<ffffffff8118b4f3>] ? __fget_light+0x62/0x71 [39389.800016] [<ffffffff8118240e>] SyS_ioctl+0x57/0x79 [39389.800016] [<ffffffff814872d7>] entry_SYSCALL_64_fastpath+0x12/0x6f [39389.800016] Code: b9 01 01 00 00 f7 c6 00 ff ff ff 75 32 83 fe 01 89 ca 89 f0 0f 45 d7 f0 0f b1 13 39 f0 74 04 89 c6 eb e2 ff ca 0f 84 fa 00 00 00 <8b> 03 84 c0 74 04 f3 90 eb f6 66 c7 03 01 00 e9 e6 00 00 00 e8 [39389.800012] Modules linked in: btrfs dm_mod ppdev xor sha256_generic hmac raid6_pq drbg ansi_cprng aesni_intel i2c_piix4 acpi_cpufreq aes_x86_64 ablk_helper tpm_tis parport_pc i2c_core sg cryptd evdev psmouse lrw tpm parport gf128mul serio_raw pcspkr glue_helper processor button loop autofs4 ext4 crc16 mbcache jbd2 sd_mod sr_mod cdrom ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring crc32c_intel scsi_mod e1000 virtio floppy [last unloaded: btrfs] [39389.800012] irq event stamp: 0 [39389.800012] hardirqs last enabled at (0): [< (null)>] (null) [39389.800012] hardirqs last disabled at (0): [<ffffffff8104e58d>] copy_process+0x638/0x1a35 [39389.800012] softirqs last enabled at (0): [<ffffffff8104e58d>] copy_process+0x638/0x1a35 [39389.800012] softirqs last disabled at (0): [< (null)>] (null) [39389.800012] CPU: 15 PID: 32166 Comm: fdm-stress Tainted: G L 4.4.0-rc6-btrfs-next-18+ #1 [39389.800012] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [39389.800012] task: ffff880179294380 ti: ffff880034a60000 task.ti: ffff880034a60000 [39389.800012] RIP: 0010:[<ffffffff81091e8d>] [<ffffffff81091e8d>] queued_write_lock_slowpath+0x62/0x72 [39389.800012] RSP: 0018:ffff880034a639f0 EFLAGS: 00000206 [39389.800012] RAX: 0000000000000101 RBX: ffff8801710c4e98 RCX: 0000000000000000 [39389.800012] RDX: 00000000000000ff RSI: 0000000000000000 RDI: ffff8801710c4e9c [39389.800012] RBP: ffff880034a639f8 R08: 0000000000000001 R09: 0000000000000000 [39389.800012] R10: ffff880034a639b0 R11: 0000000000001000 R12: ffff8801710c4e98 [39389.800012] R13: 0000000000000001 R14: ffff880172cbc000 R15: ffff8801710c4e00 [39389.800012] FS: 00007f6d377fe700(0000) GS:ffff8802be9e0000(0000) knlGS:0000000000000000 [39389.800012] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [39389.800012] CR2: 00007f6d3d3c1000 CR3: 0000000037c93000 CR4: 00000000001406e0 [39389.800012] Stack: [39389.800012] ffff8801710c4e98 ffff880034a63a10 ffffffff81091963 ffff8801710c4e98 [39389.800012] ffff880034a63a30 ffffffff81486f1b ffffffffa0672cb3 ffff8801710c4e00 [39389.800012] ffff880034a63a78 ffffffffa0672cb3 ffff8801710c4e00 ffff880034a63a58 [39389.800012] Call Trace: [39389.800012] [<ffffffff81091963>] do_raw_write_lock+0x72/0x8c [39389.800012] [<ffffffff81486f1b>] _raw_write_lock+0x3a/0x41 [39389.800012] [<ffffffffa0672cb3>] ? btrfs_tree_lock+0x119/0x251 [btrfs] [39389.800012] [<ffffffffa0672cb3>] btrfs_tree_lock+0x119/0x251 [btrfs] [39389.800012] [<ffffffffa061aeba>] ? rcu_read_unlock+0x5b/0x5d [btrfs] [39389.800012] [<ffffffffa061ce13>] ? btrfs_root_node+0xda/0xe6 [btrfs] [39389.800012] [<ffffffffa061ce83>] btrfs_lock_root_node+0x22/0x42 [btrfs] [39389.800012] [<ffffffffa062046b>] btrfs_search_slot+0x1b8/0x758 [btrfs] [39389.800012] [<ffffffff810fc6b0>] ? time_hardirqs_on+0x15/0x28 [39389.800012] [<ffffffffa06365db>] btrfs_lookup_inode+0x31/0x95 [btrfs] [39389.800012] [<ffffffff8108d62f>] ? trace_hardirqs_on+0xd/0xf [39389.800012] [<ffffffff8148482b>] ? mutex_lock_nested+0x397/0x3bc [39389.800012] [<ffffffffa068821b>] __btrfs_update_delayed_inode+0x59/0x1c0 [btrfs] [39389.800012] [<ffffffffa068858e>] __btrfs_commit_inode_delayed_items+0x194/0x5aa [btrfs] [39389.800012] [<ffffffff81486ab7>] ? _raw_spin_unlock+0x31/0x44 [39389.800012] [<ffffffffa0688a48>] __btrfs_run_delayed_items+0xa4/0x15c [btrfs] [39389.800012] [<ffffffffa0688d62>] btrfs_run_delayed_items+0x11/0x13 [btrfs] [39389.800012] [<ffffffffa064048e>] btrfs_commit_transaction+0x234/0x96e [btrfs] [39389.800012] [<ffffffffa0618d10>] btrfs_sync_fs+0x145/0x1ad [btrfs] [39389.800012] [<ffffffffa0671176>] btrfs_ioctl+0x11d2/0x2793 [btrfs] [39389.800012] [<ffffffff8108a8b0>] ? arch_local_irq_save+0x9/0xc [39389.800012] [<ffffffff81140261>] ? __might_fault+0x4c/0xa7 [39389.800012] [<ffffffff81140261>] ? __might_fault+0x4c/0xa7 [39389.800012] [<ffffffff8108a8b0>] ? arch_local_irq_save+0x9/0xc [39389.800012] [<ffffffff8118b3d4>] ? rcu_read_unlock+0x3e/0x5d [39389.800012] [<ffffffff811822f8>] do_vfs_ioctl+0x42b/0x4ea [39389.800012] [<ffffffff8118b4f3>] ? __fget_light+0x62/0x71 [39389.800012] [<ffffffff8118240e>] SyS_ioctl+0x57/0x79 [39389.800012] [<ffffffff814872d7>] entry_SYSCALL_64_fastpath+0x12/0x6f [39389.800012] Code: f0 0f b1 13 85 c0 75 ef eb 2a f3 90 8a 03 84 c0 75 f8 f0 0f b0 13 84 c0 75 f0 ba ff 00 00 00 eb 0a f0 0f b1 13 ff c8 74 0b f3 90 <8b> 03 83 f8 01 75 f7 eb ed c6 43 04 00 5b 5d c3 0f 1f 44 00 00 This happens because in the code path executed by the inode_paths ioctl we end up nesting two calls to read lock a leaf's rwlock when after the first call to read_lock() and before the second call to read_lock(), another task (running the delayed items as part of a transaction commit) has already called write_lock() against the leaf's rwlock. This situation is illustrated by the following diagram: Task A Task B btrfs_ref_to_path() btrfs_commit_transaction() read_lock(&eb->lock); btrfs_run_delayed_items() __btrfs_commit_inode_delayed_items() __btrfs_update_delayed_inode() btrfs_lookup_inode() write_lock(&eb->lock); --> task waits for lock read_lock(&eb->lock); --> makes this task hang forever (and task B too of course) So fix this by avoiding doing the nested read lock, which is easily avoidable. This issue does not happen if task B calls write_lock() after task A does the second call to read_lock(), however there does not seem to exist anything in the documentation that mentions what is the expected behaviour for recursive locking of rwlocks (leaving the idea that doing so is not a good usage of rwlocks). Also, as a side effect necessary for this fix, make sure we do not needlessly read lock extent buffers when the input path has skip_locking set (used when called from send). Signed-off-by:
-
