- 21 Sep, 2015 20 commits
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Max Filippov authored
commit 4229fb12 upstream. Userspace return code may skip restoring THREADPTR register if there are no registers that need to be zeroed. This leads to spurious failures in libc NPTL tests. Always restore THREADPTR on return to userspace. Signed-off-by:
Max Filippov <jcmvbkbc@gmail.com> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Xiao Guangrong authored
commit 6f691251 upstream. We got the bug that qemu complained with "KVM: unknown exit, hardware reason 31" and KVM shown these info: [84245.284948] EPT: Misconfiguration. [84245.285056] EPT: GPA: 0xfeda848 [84245.285154] ept_misconfig_inspect_spte: spte 0x5eaef50107 level 4 [84245.285344] ept_misconfig_inspect_spte: spte 0x5f5fadc107 level 3 [84245.285532] ept_misconfig_inspect_spte: spte 0x5141d18107 level 2 [84245.285723] ept_misconfig_inspect_spte: spte 0x52e40dad77 level 1 This is because we got a mmio #PF and the handler see the mmio spte becomes normal (points to the ram page) However, this is valid after introducing fast mmio spte invalidation which increases the generation-number instead of zapping mmio sptes, a example is as follows: 1. QEMU drops mmio region by adding a new memslot 2. invalidate all mmio sptes 3. VCPU 0 VCPU 1 access the invalid mmio spte access the region originally was MMIO before set the spte to the normal ram map mmio #PF check the spte and see it becomes normal ram mapping !!! This patch fixes the bug just by dropping the check in mmio handler, it's good for backport. Full check will be introduced in later patches Reported-by:
Pavel Shirshov <ru.pchel@gmail.com> Tested-by:
Xiao Guangrong <guangrong.xiao@linux.intel.com> Cc: stable@vger.kernel.org Signed-off-by:
Paolo Bonzini <pbonzini@redhat.com> Signed-off-by:
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Don Zickus authored
commit 3af4e5a9 upstream. It was reported that after 10-20 reboots, a usb keyboard plugged into a docking station would not work unless it was replugged in. Using usbmon, it turns out the interrupt URBs were streaming with callback errors of -71 for some reason. The hid-core.c::hid_io_error was supposed to retry and then reset, but the reset wasn't really happening. The check for HID_NO_BANDWIDTH was inverted. Fix was simple. Tested by reporter and locally by me by unplugging a keyboard halfway until I could recreate a stream of errors but no disconnect. Signed-off-by:
Don Zickus <dzickus@redhat.com> Signed-off-by:
Jiri Kosina <jkosina@suse.cz> Signed-off-by:
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Andrey Ryabinin authored
commit 71c6da84 upstream. Currently context size (cra_ctxsize) doesn't specified for ghash_async_alg. Which means it's zero. Thus crypto_create_tfm() doesn't allocate needed space for ghash_async_ctx, so any read/write to ctx (e.g. in ghash_async_init_tfm()) is not valid. Signed-off-by:
Andrey Ryabinin <aryabinin@odin.com> Signed-off-by:
Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by:
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Maciej S. Szmigiero authored
commit ffa34de0 upstream. SMSC IrCC SIR/FIR port should not be bound to by (legacy) serial driver so its own driver (smsc-ircc2) can bind to it. Signed-off-by:
Maciej Szmigiero <mail@maciej.szmigiero.name> Signed-off-by:
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Peter Chen authored
commit 0521cfd0 upstream. The ehci platform device's drvdata is the pointer of struct usb_hcd already, so we doesn't need to call bus_to_hcd conversion again. Signed-off-by:
Peter Chen <peter.chen@freescale.com> Acked-by:
Alan Stern <stern@rowland.harvard.edu> Signed-off-by:
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Kishon Vijay Abraham I authored
commit b2fb5b1a upstream. DWC3 uses bounce buffer to handle non max packet aligned OUT transfers and the size of bounce buffer is 512 bytes. However if the host initiates OUT transfers of size more than 512 bytes (and non max packet aligned), the driver throws a WARN dump but still programs the TRB to receive more than 512 bytes. This will cause bounce buffer to overflow and corrupt the adjacent memory locations which can be fatal. Fix it by programming the TRB to receive a maximum of DWC3_EP0_BOUNCE_SIZE (512) bytes. Signed-off-by:
Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by:
Felipe Balbi <balbi@ti.com> Signed-off-by:
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Matthijs Kooijman authored
commit 1fb8dc36 upstream. CustomWare uses the FTDI VID with custom PIDs for their ShipModul MiniPlex products. Signed-off-by:
Matthijs Kooijman <matthijs@stdin.nl> Signed-off-by:
Johan Hovold <johan@kernel.org> Signed-off-by:
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Philipp Hachtmann authored
commit 951d3793 upstream. The driver used usb_get_serial_data(port->serial) which compiled but resulted in a NULL pointer being returned (and subsequently used). I did not go deeper into this but I guess this is a regression. Signed-off-by:
Philipp Hachtmann <hachti@hachti.de> Fixes: a85796ee ("USB: symbolserial: move private-data allocation to port_probe") Acked-by:
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Bjorn Helgaas authored
commit d1541dc9 upstream. In fixup_ti816x_class(), we assigned "class = PCI_CLASS_MULTIMEDIA_VIDEO". But PCI_CLASS_MULTIMEDIA_VIDEO is only the two-byte base class/sub-class and needs to be shifted to make space for the low-order interface byte. Shift PCI_CLASS_MULTIMEDIA_VIDEO to set the correct class code. Fixes: 63c44080 ("PCI: Add quirk for setting valid class for TI816X Endpoint") Signed-off-by:
Bjorn Helgaas <bhelgaas@google.com> CC: Hemant Pedanekar <hemantp@ti.com> Signed-off-by:
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Dan Carpenter authored
commit 3294bee8 upstream. The ">" should be ">=" or we end up reading beyond the end of the array. Fixes: 6e973d2c ('clk: vexpress: Add separate SP810 driver') Signed-off-by:
Dan Carpenter <dan.carpenter@oracle.com> Acked-by:
Pawel Moll <pawel.moll@arm.com> Signed-off-by:
Stephen Boyd <sboyd@codeaurora.org> Signed-off-by:
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Ian Abbott authored
commit ad83dbd9 upstream. The "adl_pci7x3x" driver replaced the "adl_pci7230" and "adl_pci7432" drivers in commits 8f567c37 ("staging: comedi: new adl_pci7x3x driver") and 657f77d1 ("staging: comedi: remove adl_pci7230 and adl_pci7432 drivers"). Although the new driver code agrees with the user manuals for the respective boards, digital outputs stopped working on the PCI-7230. This has 16 digital output channels and the previous adl_pci7230 driver shifted the 16 bit output state left by 16 bits before writing to the hardware register. The new adl_pci7x3x driver doesn't do that. Fix it in `adl_pci7x3x_do_insn_bits()` by checking for the special case of the subdevice having only 16 channels and duplicating the 16 bit output state into both halves of the 32-bit register. That should work both for what the board actually does and for what the user manual says it should do. Fixes: 8f567c37 ("staging: comedi: new adl_pci7x3x driver") Signed-off-by:
Ian Abbott <abbotti@mev.co.uk> Signed-off-by:
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Lars-Peter Clausen authored
commit 7abad106 upstream. The different devices support by the adis16480 driver have slightly different scales for the gyroscope and accelerometer channels. Signed-off-by:
Lars-Peter Clausen <lars@metafoo.de> Signed-off-by:
Jonathan Cameron <jic23@kernel.org> Signed-off-by:
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Lars-Peter Clausen authored
commit c689a923 upstream. Add inverse unit conversion macro to convert from standard IIO units to units that might be used by some devices. Those are useful in combination with scale factors that are specified as IIO_VAL_FRACTIONAL. Typically the denominator for those specifications will contain the maximum raw value the sensor will generate and the numerator the value it maps to in a specific unit. Sometimes datasheets specify those in different units than the standard IIO units (e.g. degree/s instead of rad/s) and so we need to do a unit conversion. From a mathematical point of view it does not make a difference whether we apply the unit conversion to the numerator or the inverse unit conversion to the denominator since (x / y) / z = x / (y * z). But as the denominator is typically a larger value and we are rounding both the numerator and denominator to integer values using the later method gives us a better precision (E.g. the relative error is smaller if we round 8000.3 to 8000 rather than rounding 8.3 to 8). This is where in inverse unit conversion macros will be used. Marked for stable as used by some upcoming fixes. Signed-off-by:
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Cristina Opriceana authored
commit 1bdc0293 upstream. Change return value to 0 if no device is bound since unsigned int cannot support negative error codes. Fixes: f18e7a06 ("iio: Return -ENODEV for file operations if the device has been unregistered") Signed-off-by:
Cristina Opriceana <cristina.opriceana@gmail.com> Signed-off-by:
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Cristina Opriceana authored
commit 41d903c0 upstream. Negative return values are not supported by iio_event_poll since its return type is unsigned int. Fixes: f18e7a06 ("iio: Return -ENODEV for file operations if the device has been unregistered") Signed-off-by:
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Markus Pargmann authored
commit 06d2f6ca upstream. This patch adds selects for IIO_BUFFER and IIO_TRIGGERED_BUFFER. Without IIO_BUFFER, the driver does not compile. Signed-off-by:
Markus Pargmann <mpa@pengutronix.de> Reviewed-by:
Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by:
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Sebastian Ott authored
commit a313bdc5 upstream. Fix this error when compiling with CONFIG_SMP=n and CONFIG_DYNAMIC_DEBUG=y: drivers/s390/char/sclp_early.c: In function 'sclp_read_info_early': drivers/s390/char/sclp_early.c:87:19: error: 'EBUSY' undeclared (first use in this function) } while (rc == -EBUSY); ^ Signed-off-by:
Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by:
Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by:
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Jonathon Jongsma authored
commit bd3e1c7c upstream. Due to some recent changes in drm_helper_probe_single_connector_modes_merge_bits(), old custom modes were not being pruned properly. In current kernels, drm_mode_validate_basic() is called to sanity-check each mode in the list. If the sanity-check passes, the mode's status gets set to to MODE_OK. In older kernels this check was not done, so old custom modes would still have a status of MODE_UNVERIFIED at this point, and would therefore be pruned later in the function. As a result of this new behavior, the list of modes for a device always includes every custom mode ever configured for the device, with the largest one listed first. Since desktop environments usually choose the first preferred mode when a hotplug event is emitted, this had the result of making it very difficult for the user to reduce the size of the display. The qxl driver did implement the mode_valid connector function, but it was empty. In order to restore the old behavior where old custom modes are pruned, we implement a proper mode_valid function for the qxl driver. This function now checks each mode against the last configured custom mode and the list of standard modes. If the mode doesn't match any of these, its status is set to MODE_BAD so that it will be pruned as expected. Signed-off-by:
Jonathon Jongsma <jjongsma@redhat.com> Signed-off-by:
Dave Airlie <airlied@redhat.com> Signed-off-by:
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Stephen Chandler Paul authored
commit 924f92bf upstream. Most of the time this isn't an issue since hotplugging an adaptor will trigger a crtc mode change which in turn, causes the driver to probe every DisplayPort for a dpcd. However, in cases where hotplugging doesn't cause a mode change (specifically when one unplugs a monitor from a DisplayPort connector, then plugs that same monitor back in seconds later on the same port without any other monitors connected), we never probe for the dpcd before starting the initial link training. What happens from there looks like this: - GPU has only one monitor connected. It's connected via DisplayPort, and does not go through an adaptor of any sort. - User unplugs DisplayPort connector from GPU. - Change in HPD is detected by the driver, we probe every DisplayPort for a possible connection. - Probe the port the user originally had the monitor connected on for it's dpcd. This fails, and we clear the first (and only the first) byte of the dpcd to indicate we no longer have a dpcd for this port. - User plugs the previously disconnected monitor back into the same DisplayPort. - radeon_connector_hotplug() is called before everyone else, and tries to handle the link training. Since only the first byte of the dpcd is zeroed, the driver is able to complete link training but does so against the wrong dpcd, causing it to initialize the link with the wrong settings. - Display stays blank (usually), dpcd is probed after the initial link training, and the driver prints no obvious messages to the log. In theory, since only one byte of the dpcd is chopped off (specifically, the byte that contains the revision information for DisplayPort), it's not entirely impossible that this bug may not show on certain monitors. For instance, the only reason this bug was visible on my ASUS PB238 monitor was due to the fact that this monitor using the enhanced framing symbol sequence, the flag for which is ignored if the radeon driver thinks that the DisplayPort version is below 1.1. Signed-off-by:
Stephen Chandler Paul <cpaul@redhat.com> Reviewed-by:
Jerome Glisse <jglisse@redhat.com> Signed-off-by:
Alex Deucher <alexander.deucher@amd.com> Signed-off-by:
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- 13 Sep, 2015 19 commits
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Greg Kroah-Hartman authored
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Marc Zyngier authored
commit 126c69a0 upstream. When injecting a fault into a misbehaving 32bit guest, it seems rather idiotic to also inject a 64bit fault that is only going to corrupt the guest state. This leads to a situation where we perform an illegal exception return at EL2 causing the host to crash instead of killing the guest. Just fix the stupid bug that has been there from day 1. Reported-by:
Russell King <rmk+kernel@arm.linux.org.uk> Tested-by:
Marc Zyngier <marc.zyngier@arm.com> Signed-off-by:
Will Deacon <will.deacon@arm.com> Signed-off-by:
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Alan Stern authored
commit 49718f0f upstream. The routines in scsi_rpm.c assume that if a runtime-PM callback is invoked for a SCSI device, it can only mean that the device's driver has asked the block layer to handle the runtime power management (by calling blk_pm_runtime_init(), which among other things sets q->dev). However, this assumption turns out to be wrong for things like the ses driver. Normally ses devices are not allowed to do runtime PM, but userspace can override this setting. If this happens, the kernel gets a NULL pointer dereference when blk_post_runtime_resume() tries to use the uninitialized q->dev pointer. This patch fixes the problem by calling the block layer's runtime-PM routines only if the device's driver really does have a runtime-PM callback routine. Since ses doesn't define any such callbacks, the crash won't occur. This fixes Bugzilla #101371. Signed-off-by:
Stanisław Pitucha <viraptor@gmail.com> Reported-by:
Ilan Cohen <ilanco@gmail.com> Tested-by:
Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by:
James Bottomley <JBottomley@Odin.com> Signed-off-by:
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Yann Droneaud authored
commit d6c763af upstream. Since commit 8a0a9bd4 ('random: make get_random_int() more random'), get_random_int() returns a random value for each call, so comment and hack introduced in mmap_rnd() as part of commit 1d18c47c ('arm64: MMU fault handling and page table management') are incorrects. Commit 1d18c47c seems to use the same hack introduced by commit a5adc91a ('powerpc: Ensure random space between stack and mmaps'), latter copied in commit 5a0efea0 ('sparc64: Sharpen address space randomization calculations.'). But both architectures were cleaned up as part of commit fa8cbaaf ('powerpc+sparc64/mm: Remove hack in mmap randomize layout') as hack is no more needed since commit 8a0a9bd4. So the present patch removes the comment and the hack around get_random_int() on AArch64's mmap_rnd(). Cc: David S. Miller <davem@davemloft.net> Cc: Anton Blanchard <anton@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by:
Dan McGee <dpmcgee@gmail.com> Signed-off-by:
Yann Droneaud <ydroneaud@opteya.com> Signed-off-by:
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Horia Geant? authored
commit b310c178 upstream. When doing pointer operation for accessing the HW S/G table, a value representing number of entries (and not number of bytes) must be used. Fixes: 045e3678 ("crypto: caam - ahash hmac support") Signed-off-by:
Horia Geant? <horia.geanta@freescale.com> Signed-off-by:
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Guenter Roeck authored
commit 8ef9724b upstream. When inserting a new register into a block, the present bit map size is increased using krealloc. krealloc does not clear the additionally allocated memory, leaving it filled with random values. Result is that some registers are considered cached even though this is not the case. Fix the problem by clearing the additionally allocated memory. Also, if the bitmap size does not increase, do not reallocate the bitmap at all to reduce overhead. Fixes: 3f4ff561 ("regmap: rbtree: Make cache_present bitmap per node") Signed-off-by:
Guenter Roeck <linux@roeck-us.net> Signed-off-by:
Mark Brown <broonie@kernel.org> Signed-off-by:
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Bart Van Assche authored
commit 8f2777f5 upstream. Since fc_fcp_cleanup_cmd() can sleep this function must not be called while holding a spinlock. This patch avoids that fc_fcp_cleanup_each_cmd() triggers the following bug: BUG: scheduling while atomic: sg_reset/1512/0x00000202 1 lock held by sg_reset/1512: #0: (&(&fsp->scsi_pkt_lock)->rlock){+.-...}, at: [<ffffffffc0225cd5>] fc_fcp_cleanup_each_cmd.isra.21+0xa5/0x150 [libfc] Preemption disabled at:[<ffffffffc0225cd5>] fc_fcp_cleanup_each_cmd.isra.21+0xa5/0x150 [libfc] Call Trace: [<ffffffff816c612c>] dump_stack+0x4f/0x7b [<ffffffff810828bc>] __schedule_bug+0x6c/0xd0 [<ffffffff816c87aa>] __schedule+0x71a/0xa10 [<ffffffff816c8ad2>] schedule+0x32/0x80 [<ffffffffc0217eac>] fc_seq_set_resp+0xac/0x100 [libfc] [<ffffffffc0218b11>] fc_exch_done+0x41/0x60 [libfc] [<ffffffffc0225cff>] fc_fcp_cleanup_each_cmd.isra.21+0xcf/0x150 [libfc] [<ffffffffc0225f43>] fc_eh_device_reset+0x1c3/0x270 [libfc] [<ffffffff814a2cc9>] scsi_try_bus_device_reset+0x29/0x60 [<ffffffff814a3908>] scsi_ioctl_reset+0x258/0x2d0 [<ffffffff814a2650>] scsi_ioctl+0x150/0x440 [<ffffffff814b3a9d>] sd_ioctl+0xad/0x120 [<ffffffff8132f266>] blkdev_ioctl+0x1b6/0x810 [<ffffffff811da608>] block_ioctl+0x38/0x40 [<ffffffff811b4e08>] do_vfs_ioctl+0x2f8/0x530 [<ffffffff811b50c1>] SyS_ioctl+0x81/0xa0 [<ffffffff816cf8b2>] system_call_fastpath+0x16/0x7a Signed-off-by:
Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by:
Vasu Dev <vasu.dev@intel.com> Signed-off-by:
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Bart Van Assche authored
commit f6979ade upstream. Due to patch "libfc: Do not invoke the response handler after fc_exch_done()" (commit ID 7030fd62) the lport_recv() call in fc_exch_recv_req() is passed a dangling pointer. Avoid this by moving the fc_frame_free() call from fc_invoke_resp() to its callers. This patch fixes the following crash: general protection fault: 0000 [#3] PREEMPT SMP RIP: fc_lport_recv_req+0x72/0x280 [libfc] Call Trace: fc_exch_recv+0x642/0xde0 [libfc] fcoe_percpu_receive_thread+0x46a/0x5ed [fcoe] kthread+0x10a/0x120 ret_from_fork+0x42/0x70 Signed-off-by:
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Thomas Hellstrom authored
commit 3e04e2fe upstream. This addresses two issues that cause problems with viewperf maya-03 in situation with memory pressure. The first issue causes attempts to unreserve buffers if batched reservation fails due to, for example, a signal pending. While previously the ttm_eu api was resistant against this type of error, it is no longer and the lockdep code will complain about attempting to unreserve buffers that are not reserved. The issue is resolved by avoid calling ttm_eu_backoff_reservation in the buffer reserve error path. The second issue is that the binding_mutex may be held when user-space fence objects are created and hence during memory reclaims. This may cause recursive attempts to grab the binding mutex. The issue is resolved by not holding the binding mutex across fence creation and submission. Signed-off-by:
Thomas Hellstrom <thellstrom@vmware.com> Reviewed-by:
Sinclair Yeh <syeh@vmware.com> Signed-off-by:
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Alex Deucher authored
commit e037239e upstream. Signed-off-by:
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Michael Walle authored
commit 5c16179b upstream. The commit de3910eb ("edac: change the mem allocation scheme to make Documentation/kobject.txt happy") changed the memory allocation for the csrows member. But ppc4xx_edac was forgotten in the patch. Fix it. Signed-off-by:
Michael Walle <michael@walle.cc> Cc: linux-edac <linux-edac@vger.kernel.org> Cc: Mauro Carvalho Chehab <mchehab@osg.samsung.com> Link: http://lkml.kernel.org/r/1437469253-8611-1-git-send-email-michael@walle.ccSigned-off-by:
Borislav Petkov <bp@suse.de> Signed-off-by:
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Richard Weinberger authored
commit c0ddc8c7 upstream. In kbuild it is allowed to define objects in files named "Makefile" and "Kbuild". Currently localmodconfig reads objects only from "Makefile"s and misses modules like nouveau. Link: http://lkml.kernel.org/r/1437948415-16290-1-git-send-email-richard@nod.atReported-and-tested-by:
Leonidas Spyropoulos <artafinde@gmail.com> Signed-off-by:
Richard Weinberger <richard@nod.at> Signed-off-by:
Steven Rostedt <rostedt@goodmis.org> Signed-off-by:
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Joe Thornber authored
commit 7f518ad0 upstream. The device details and mapping trees were just being decremented before. Now btree_del() is called to do a deep delete. Signed-off-by:
Joe Thornber <ejt@redhat.com> Signed-off-by:
Mike Snitzer <snitzer@redhat.com> Signed-off-by:
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Peter Zijlstra authored
commit c7999c6f upstream. I ran the perf fuzzer, which triggered some WARN()s which are due to trying to stop/restart an event on the wrong CPU. Use the normal IPI pattern to ensure we run the code on the correct CPU. Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: bad7192b ("perf: Fix PERF_EVENT_IOC_PERIOD to force-reset the period") Signed-off-by:
Ingo Molnar <mingo@kernel.org> Signed-off-by:
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Peter Zijlstra authored
commit fed66e2c upstream. Vince reported that the fasync signal stuff doesn't work proper for inherited events. So fix that. Installing fasync allocates memory and sets filp->f_flags |= FASYNC, which upon the demise of the file descriptor ensures the allocation is freed and state is updated. Now for perf, we can have the events stick around for a while after the original FD is dead because of references from child events. So we cannot copy the fasync pointer around. We can however consistently use the parent's fasync, as that will be updated. Reported-and-Tested-by:
Vince Weaver <vincent.weaver@maine.edu> Signed-off-by:
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Bob Liu authored
commit 7b076750 upstream. We should consider info->feature_persistent when adding indirect page to list info->indirect_pages, else the BUG_ON() in blkif_free() would be triggered. When we are using persistent grants the indirect_pages list should always be empty because blkfront has pre-allocated enough persistent pages to fill all requests on the ring. Acked-by:
Roger Pau Monné <roger.pau@citrix.com> Signed-off-by:
Bob Liu <bob.liu@oracle.com> Signed-off-by:
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by:
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Wanpeng Li authored
commit 4f32be67 upstream. After trying to drain pages from pagevec/pageset, we try to get reference count of the page again, however, the reference count of the page is not reduced if the page is still not on LRU list. Fix it by adding the put_page() to drop the page reference which is from __get_any_page(). Signed-off-by:
Wanpeng Li <wanpeng.li@hotmail.com> Acked-by:
Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
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Manfred Spraul authored
commit 3ed1f8a9 upstream. sem_lock() did not properly pair memory barriers: !spin_is_locked() and spin_unlock_wait() are both only control barriers. The code needs an acquire barrier, otherwise the cpu might perform read operations before the lock test. As no primitive exists inside <include/spinlock.h> and since it seems noone wants another primitive, the code creates a local primitive within ipc/sem.c. With regards to -stable: The change of sem_wait_array() is a bugfix, the change to sem_lock() is a nop (just a preprocessor redefinition to improve the readability). The bugfix is necessary for all kernels that use sem_wait_array() (i.e.: starting from 3.10). Signed-off-by:
Manfred Spraul <manfred@colorfullife.com> Reported-by:
Oleg Nesterov <oleg@redhat.com> Acked-by:
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Herton R. Krzesinski authored
commit 602b8593 upstream. The current semaphore code allows a potential use after free: in exit_sem we may free the task's sem_undo_list while there is still another task looping through the same semaphore set and cleaning the sem_undo list at freeary function (the task called IPC_RMID for the same semaphore set). For example, with a test program [1] running which keeps forking a lot of processes (which then do a semop call with SEM_UNDO flag), and with the parent right after removing the semaphore set with IPC_RMID, and a kernel built with CONFIG_SLAB, CONFIG_SLAB_DEBUG and CONFIG_DEBUG_SPINLOCK, you can easily see something like the following in the kernel log: Slab corruption (Not tainted): kmalloc-64 start=ffff88003b45c1c0, len=64 000: 6b 6b 6b 6b 6b 6b 6b 6b 00 6b 6b 6b 6b 6b 6b 6b kkkkkkkk.kkkkkkk 010: ff ff ff ff 6b 6b 6b 6b ff ff ff ff ff ff ff ff ....kkkk........ Prev obj: start=ffff88003b45c180, len=64 000: 00 00 00 00 ad 4e ad de ff ff ff ff 5a 5a 5a 5a .....N......ZZZZ 010: ff ff ff ff ff ff ff ff c0 fb 01 37 00 88 ff ff ...........7.... Next obj: start=ffff88003b45c200, len=64 000: 00 00 00 00 ad 4e ad de ff ff ff ff 5a 5a 5a 5a .....N......ZZZZ 010: ff ff ff ff ff ff ff ff 68 29 a7 3c 00 88 ff ff ........h).<.... BUG: spinlock wrong CPU on CPU#2, test/18028 general protection fault: 0000 [#1] SMP Modules linked in: 8021q mrp garp stp llc nf_conntrack_ipv4 nf_defrag_ipv4 ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables binfmt_misc ppdev input_leds joydev parport_pc parport floppy serio_raw virtio_balloon virtio_rng virtio_console virtio_net iosf_mbi crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcspkr qxl ttm drm_kms_helper drm snd_hda_codec_generic i2c_piix4 snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_seq snd_seq_device snd_pcm snd_timer snd soundcore crc32c_intel virtio_pci virtio_ring virtio pata_acpi ata_generic [last unloaded: speedstep_lib] CPU: 2 PID: 18028 Comm: test Not tainted 4.2.0-rc5+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.1-20150318_183358- 04/01/2014 RIP: spin_dump+0x53/0xc0 Call Trace: spin_bug+0x30/0x40 do_raw_spin_unlock+0x71/0xa0 _raw_spin_unlock+0xe/0x10 freeary+0x82/0x2a0 ? _raw_spin_lock+0xe/0x10 semctl_down.clone.0+0xce/0x160 ? __do_page_fault+0x19a/0x430 ? __audit_syscall_entry+0xa8/0x100 SyS_semctl+0x236/0x2c0 ? syscall_trace_leave+0xde/0x130 entry_SYSCALL_64_fastpath+0x12/0x71 Code: 8b 80 88 03 00 00 48 8d 88 60 05 00 00 48 c7 c7 a0 2c a4 81 31 c0 65 8b 15 eb 40 f3 7e e8 08 31 68 00 4d 85 e4 44 8b 4b 08 74 5e <45> 8b 84 24 88 03 00 00 49 8d 8c 24 60 05 00 00 8b 53 04 48 89 RIP [<ffffffff810d6053>] spin_dump+0x53/0xc0 RSP <ffff88003750fd68> ---[ end trace 783ebb76612867a0 ]--- NMI watchdog: BUG: soft lockup - CPU#3 stuck for 22s! [test:18053] Modules linked in: 8021q mrp garp stp llc nf_conntrack_ipv4 nf_defrag_ipv4 ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables binfmt_misc ppdev input_leds joydev parport_pc parport floppy serio_raw virtio_balloon virtio_rng virtio_console virtio_net iosf_mbi crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcspkr qxl ttm drm_kms_helper drm snd_hda_codec_generic i2c_piix4 snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_seq snd_seq_device snd_pcm snd_timer snd soundcore crc32c_intel virtio_pci virtio_ring virtio pata_acpi ata_generic [last unloaded: speedstep_lib] CPU: 3 PID: 18053 Comm: test Tainted: G D 4.2.0-rc5+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.1-20150318_183358- 04/01/2014 RIP: native_read_tsc+0x0/0x20 Call Trace: ? delay_tsc+0x40/0x70 __delay+0xf/0x20 do_raw_spin_lock+0x96/0x140 _raw_spin_lock+0xe/0x10 sem_lock_and_putref+0x11/0x70 SYSC_semtimedop+0x7bf/0x960 ? handle_mm_fault+0xbf6/0x1880 ? dequeue_task_fair+0x79/0x4a0 ? __do_page_fault+0x19a/0x430 ? kfree_debugcheck+0x16/0x40 ? __do_page_fault+0x19a/0x430 ? __audit_syscall_entry+0xa8/0x100 ? do_audit_syscall_entry+0x66/0x70 ? syscall_trace_enter_phase1+0x139/0x160 SyS_semtimedop+0xe/0x10 SyS_semop+0x10/0x20 entry_SYSCALL_64_fastpath+0x12/0x71 Code: 47 10 83 e8 01 85 c0 89 47 10 75 08 65 48 89 3d 1f 74 ff 7e c9 c3 0f 1f 44 00 00 55 48 89 e5 e8 87 17 04 00 66 90 c9 c3 0f 1f 00 <55> 48 89 e5 0f 31 89 c1 48 89 d0 48 c1 e0 20 89 c9 48 09 c8 c9 Kernel panic - not syncing: softlockup: hung tasks I wasn't able to trigger any badness on a recent kernel without the proper config debugs enabled, however I have softlockup reports on some kernel versions, in the semaphore code, which are similar as above (the scenario is seen on some servers running IBM DB2 which uses semaphore syscalls). The patch here fixes the race against freeary, by acquiring or waiting on the sem_undo_list lock as necessary (exit_sem can race with freeary, while freeary sets un->semid to -1 and removes the same sem_undo from list_proc or when it removes the last sem_undo). After the patch I'm unable to reproduce the problem using the test case [1]. [1] Test case used below: #include <stdio.h> #include <sys/types.h> #include <sys/ipc.h> #include <sys/sem.h> #include <sys/wait.h> #include <stdlib.h> #include <time.h> #include <unistd.h> #include <errno.h> #define NSEM 1 #define NSET 5 int sid[NSET]; void thread() { struct sembuf op; int s; uid_t pid = getuid(); s = rand() % NSET; op.sem_num = pid % NSEM; op.sem_op = 1; op.sem_flg = SEM_UNDO; semop(sid[s], &op, 1); exit(EXIT_SUCCESS); } void create_set() { int i, j; pid_t p; union { int val; struct semid_ds *buf; unsigned short int *array; struct seminfo *__buf; } un; /* Create and initialize semaphore set */ for (i = 0; i < NSET; i++) { sid[i] = semget(IPC_PRIVATE , NSEM, 0644 | IPC_CREAT); if (sid[i] < 0) { perror("semget"); exit(EXIT_FAILURE); } } un.val = 0; for (i = 0; i < NSET; i++) { for (j = 0; j < NSEM; j++) { if (semctl(sid[i], j, SETVAL, un) < 0) perror("semctl"); } } /* Launch threads that operate on semaphore set */ for (i = 0; i < NSEM * NSET * NSET; i++) { p = fork(); if (p < 0) perror("fork"); if (p == 0) thread(); } /* Free semaphore set */ for (i = 0; i < NSET; i++) { if (semctl(sid[i], NSEM, IPC_RMID)) perror("IPC_RMID"); } /* Wait for forked processes to exit */ while (wait(NULL)) { if (errno == ECHILD) break; }; } int main(int argc, char **argv) { pid_t p; srand(time(NULL)); while (1) { p = fork(); if (p < 0) { perror("fork"); exit(EXIT_FAILURE); } if (p == 0) { create_set(); goto end; } /* Wait for forked processes to exit */ while (wait(NULL)) { if (errno == ECHILD) break; }; } end: return 0; } [akpm@linux-foundation.org: use normal comment layout] Signed-off-by:
Herton R. Krzesinski <herton@redhat.com> Acked-by:
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- 17 Aug, 2015 1 commit
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Greg Kroah-Hartman authored
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