- 19 Jan, 2017 40 commits
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Mathias Nyman authored
commit d6169d04 upstream. If a URB is killed while the host is removed we can end up in a situation where the hub thread takes the roothub device lock, and waits for the URB to be given back by xhci-hcd, blocking the host remove code. xhci-hcd tries to stop the endpoint and give back the urb, but can't as the host is removed from PCI bus at the same time, preventing the normal way of giving back urb. Instead we need to rely on the stop command timeout function to give back the urb. This xhci_stop_endpoint_command_watchdog() timeout function used a XHCI_STATE_DYING flag to indicate if the timeout function is already running, but later this flag has been taking into use in other places to mark that xhci is dying. Remove checks for XHCI_STATE_DYING in xhci_urb_dequeue. We are still checking that reading from pci state does not return 0xffffffff or that host is not halted before trying to stop the endpoint. This whole area of stopping endpoints, giving back URBs, and the wathdog timeout need rework, this fix focuses on solving a specific deadlock issue that we can then send to stable before any major rework. Signed-off-by:
Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Al Viro authored
commit b9dc6f65 upstream. The logics in pipe_advance() used to release all buffers past the new position failed in cases when the number of buffers to release was equal to pipe->buffers. If that happened, none of them had been released, leaving pipe full. Worse, it was trivial to trigger and we end up with pipe full of uninitialized pages. IOW, it's an infoleak. Reported-by:
"Alan J. Wylie" <alan@wylie.me.uk> Tested-by:
Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:
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Vlad Tsyrklevich authored
commit 30f939fe upstream. i2c_smbus_xfer() does not always fill an entire block, allowing kernel stack memory disclosure through the temp variable. Clear it before it's read to. Signed-off-by:
Vlad Tsyrklevich <vlad@tsyrklevich.net> Signed-off-by:
Wolfram Sang <wsa@the-dreams.de> Signed-off-by:
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John Garry authored
commit 6f724fb3 upstream. In of_i2c_register_device(), when the check for device address validity fails we print the info.addr, which has not been assigned properly. Fix this by printing the actual invalid address. Signed-off-by:
John Garry <john.garry@huawei.com> Reviewed-by:
Vladimir Zapolskiy <vz@mleia.com> Signed-off-by:
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Guenter Roeck authored
commit 1c3415a0 upstream. The following crash may be seen if bad data is received from the touchscreen. [ 2189.425150] elants_i2c i2c-ELAN0001:00: unknown packet ff ff ff ff [ 2189.430738] divide error: 0000 [#1] PREEMPT SMP [ 2189.434679] gsmi: Log Shutdown Reason 0x03 [ 2189.434689] Modules linked in: ip6t_REJECT nf_reject_ipv6 rfcomm evdi uinput uvcvideo cmac videobuf2_vmalloc videobuf2_memops snd_hda_codec_hdmi i2c_dev videobuf2_core snd_soc_sst_cht_bsw_rt5645 snd_hda_intel snd_intel_sst_acpi btusb btrtl btbcm btintel bluetooth snd_soc_sst_acpi snd_hda_codec snd_intel_sst_core snd_hwdep snd_soc_sst_mfld_platform snd_hda_core snd_soc_rt5645 memconsole_x86_legacy memconsole zram snd_soc_rl6231 fuse ip6table_filter iwlmvm iwlwifi iwl7000_mac80211 cfg80211 iio_trig_sysfs joydev cros_ec_sensors cros_ec_sensors_core industrialio_triggered_buffer kfifo_buf industrialio snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq snd_seq_device ppp_async ppp_generic slhc tun [ 2189.434866] CPU: 0 PID: 106 Comm: irq/184-ELAN000 Tainted: G W 3.18.0-13101-g57e8190 #1 [ 2189.434883] Hardware name: GOOGLE Ultima, BIOS Google_Ultima.7287.131.43 07/20/2016 [ 2189.434898] task: ffff88017a0b6d80 ti: ffff88017a2bc000 task.ti: ffff88017a2bc000 [ 2189.434913] RIP: 0010:[<ffffffffbecc48d5>] [<ffffffffbecc48d5>] elants_i2c_irq+0x190/0x200 [ 2189.434937] RSP: 0018:ffff88017a2bfd98 EFLAGS: 00010293 [ 2189.434948] RAX: 0000000000000000 RBX: ffff88017a967828 RCX: ffff88017a9678e8 [ 2189.434962] RDX: 0000000000000000 RSI: 0000000000000246 RDI: 0000000000000000 [ 2189.434975] RBP: ffff88017a2bfdd8 R08: 00000000000003e8 R09: 0000000000000000 [ 2189.434989] R10: 0000000000000000 R11: 000000000044a2bd R12: ffff88017a991800 [ 2189.435001] R13: ffffffffbe8a2a53 R14: ffff88017a0b6d80 R15: ffff88017a0b6d80 [ 2189.435011] FS: 0000000000000000(0000) GS:ffff88017fc00000(0000) knlGS:0000000000000000 [ 2189.435022] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 2189.435030] CR2: 00007f678d94b000 CR3: 000000003f41a000 CR4: 00000000001007f0 [ 2189.435039] Stack: [ 2189.435044] ffff88017a2bfda8 ffff88017a9678e8 646464647a2bfdd8 0000000006e09574 [ 2189.435060] 0000000000000000 ffff88017a088b80 ffff88017a921000 ffffffffbe8a2a53 [ 2189.435074] ffff88017a2bfe08 ffffffffbe8a2a73 ffff88017a0b6d80 0000000006e09574 [ 2189.435089] Call Trace: [ 2189.435101] [<ffffffffbe8a2a53>] ? irq_thread_dtor+0xa9/0xa9 [ 2189.435112] [<ffffffffbe8a2a73>] irq_thread_fn+0x20/0x40 [ 2189.435123] [<ffffffffbe8a2be1>] irq_thread+0x14e/0x222 [ 2189.435135] [<ffffffffbee8cbeb>] ? __schedule+0x3b3/0x57a [ 2189.435145] [<ffffffffbe8a29aa>] ? wake_threads_waitq+0x2d/0x2d [ 2189.435156] [<ffffffffbe8a2a93>] ? irq_thread_fn+0x40/0x40 [ 2189.435168] [<ffffffffbe87c385>] kthread+0x10e/0x116 [ 2189.435178] [<ffffffffbe87c277>] ? __kthread_parkme+0x67/0x67 [ 2189.435189] [<ffffffffbee900ac>] ret_from_fork+0x7c/0xb0 [ 2189.435199] [<ffffffffbe87c277>] ? __kthread_parkme+0x67/0x67 [ 2189.435208] Code: ff ff eb 73 0f b6 bb c1 00 00 00 83 ff 03 7e 13 49 8d 7c 24 20 ba 04 00 00 00 48 c7 c6 8a cd 21 bf eb 4d 0f b6 83 c2 00 00 00 99 <f7> ff 83 f8 37 75 15 48 6b f7 37 4c 8d a3 c4 00 00 00 4c 8d ac [ 2189.435312] RIP [<ffffffffbecc48d5>] elants_i2c_irq+0x190/0x200 [ 2189.435323] RSP <ffff88017a2bfd98> [ 2189.435350] ---[ end trace f4945345a75d96dd ]--- [ 2189.443841] Kernel panic - not syncing: Fatal exception [ 2189.444307] Kernel Offset: 0x3d800000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) [ 2189.444519] gsmi: Log Shutdown Reason 0x02 The problem was seen with a 3.18 based kernel, but there is no reason to believe that the upstream code is safe. Fixes: 66aee900 ("Input: add support for Elan eKTH I2C touchscreens") Signed-off-by:
Guenter Roeck <linux@roeck-us.net> Signed-off-by:
Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by:
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Johan Hovold authored
commit a20047f3 upstream. The private baud_rate variable is used to configure the port at open and reset-resume and must never be set to (and left at) zero or reset-resume and all further open attempts will fail. Fixes: aa91def4 ("USB: ch341: set tty baud speed according to tty struct") Fixes: 664d5df9 ("USB: usb-serial ch341: support for DTR/RTS/CTS") Signed-off-by:
Johan Hovold <johan@kernel.org> Signed-off-by:
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Johan Hovold authored
commit 2d5a9c72 upstream. A short control transfer would currently fail to be detected, something which could lead to stale buffer data being used as valid input. Check for short transfers, and make sure to log any transfer errors. Note that this also avoids leaking heap data to user space (TIOCMGET) and the remote device (break control). Fixes: 6ce76104 ("USB: Driver for CH341 USB-serial adaptor") Signed-off-by:
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Johan Hovold authored
commit f2950b78 upstream. Make sure to stop the interrupt URB before returning on errors during open. Fixes: 664d5df9 ("USB: usb-serial ch341: support for DTR/RTS/CTS") Signed-off-by:
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Johan Hovold authored
commit ce5e2928 upstream. Fix reset-resume handling which failed to resubmit the read and interrupt URBs, thereby leaving a port that was open before suspend in a broken state until closed and reopened. Fixes: 1ded7ea4 ("USB: ch341 serial: fix port number changed after resume") Fixes: 2bfd1c96 ("USB: serial: ch341: remove reset_resume callback") Signed-off-by:
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Johan Hovold authored
commit 4e2da446 upstream. DTR and RTS will be asserted by the tty-layer when the port is opened and deasserted on close (if HUPCL is set). Make sure the initial state is not-asserted before the port is first opened as well. Fixes: 664d5df9 ("USB: usb-serial ch341: support for DTR/RTS/CTS") Signed-off-by:
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Johan Hovold authored
commit 146cc8a1 upstream. The current implementation failed to detect short transfers when attempting to read the line state, and also, to make things worse, logged the content of the uninitialised heap transfer buffer. Fixes: abf492e7 ("USB: kl5kusb105: fix DMA buffers on stack") Fixes: 1da177e4 ("Linux-2.6.12-rc2") Reviewed-by:
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Bin Liu authored
commit 7b6c1b4c upstream. MUSB driver now has runtime PM support, but the debugfs driver misses the PM _get/_put() calls, which could cause MUSB register access failure. Acked-by:
Tony Lindgren <tony@atomide.com> Signed-off-by:
Bin Liu <b-liu@ti.com> Signed-off-by:
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Andy Lutomirski authored
commit 620f1a63 upstream. The driver put a constant buffer of all zeros on the stack and pointed a scatterlist entry at it. This doesn't work with virtual stacks. Use ZERO_PAGE instead. Reported-by:
Eric Biggers <ebiggers3@gmail.com> Signed-off-by:
Andy Lutomirski <luto@kernel.org> Signed-off-by:
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Borislav Petkov authored
commit a33d3317 upstream. The following commit: 8196dab4 ("x86/cpu: Get rid of compute_unit_id") ... broke the initial strategy for Bulldozer-based cores' topology, where we consider each thread of a compute unit a standalone core and not a HT or SMT thread. Revert to the firmware-supplied core_id numbering and do not make them thread siblings as we don't consider them for such even if they technically are, more or less. Reported-and-tested-by:
Brice Goglin <Brice.Goglin@inria.fr> Tested-by:
Yazen Ghannam <yazen.ghannam@amd.com> Signed-off-by:
Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 8196dab4 ("x86/cpu: Get rid of compute_unit_id") Link: http://lkml.kernel.org/r/20170105092638.5247-1-bp@alien8.deSigned-off-by:
Ingo Molnar <mingo@kernel.org> Signed-off-by:
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Thomas Gleixner authored
commit 3344ed30 upstream. The workaround for the AMD Erratum E400 (Local APIC timer stops in C1E state) is a two step process: - Selection of the E400 aware idle routine - Detection whether the platform is affected The idle routine selection happens for possibly affected CPUs depending on family/model/stepping information. These range of CPUs is not necessarily affected as the decision whether to enable the C1E feature is made by the firmware. Unfortunately there is no way to query this at early boot. The current implementation polls a MSR in the E400 aware idle routine to detect whether the CPU is affected. This is inefficient on non affected CPUs because every idle entry has to do the MSR read. There is a better way to detect this before going idle for the first time which requires to seperate the bug flags: X86_BUG_AMD_E400 - Selects the E400 aware idle routine and enables the detection X86_BUG_AMD_APIC_C1E - Set when the platform is affected by E400 Replace the current X86_BUG_AMD_APIC_C1E usage by the new X86_BUG_AMD_E400 bug bit to select the idle routine which currently does an unconditional detection poll. X86_BUG_AMD_APIC_C1E is going to be used in later patches to remove the MSR polling and simplify the handling of this misfeature. Signed-off-by:
Thomas Gleixner <tglx@linutronix.de> Signed-off-by:
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Yazen Ghannam authored
commit b6a50cdd upstream. These changes do not affect current hw - just a cleanup: Currently, we assume that a system has a single Last Level Cache (LLC) per node, and that the cpu_llc_id is thus equal to the node_id. This no longer applies since Fam17h can have multiple last level caches within a node. So group the cpu_llc_id assignment by topology feature and family in order to make the computation of cpu_llc_id on the different families more clear. Here is how the LLC ID is being computed on the different families: The NODEID_MSR feature only applies to Fam10h in which case the LLC is at the node level. The TOPOEXT feature is used on families 15h, 16h and 17h. So far we only see multiple last level caches if L3 caches are available. Otherwise, the cpu_llc_id will default to be the phys_proc_id. We have L3 caches only on families 15h and 17h: - on Fam15h, the LLC is at the node level. - on Fam17h, the LLC is at the core complex level and can be found by right shifting the APIC ID. Also, keep the family checks explicit so that new families will fall back to the default, which will be node_id for TOPOEXT systems. Single node systems in families 10h and 15h will have a Node ID of 0 which will be the same as the phys_proc_id, so we don't need to check for multiple nodes before using the node_id. Tested-by:
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Artur Molchanov authored
commit 14221cc4 upstream. Problem: br_nf_pre_routing_finish() calls itself instead of br_nf_pre_routing_finish_bridge(). Due to this bug reverse path filter drops packets that go through bridge interface. User impact: Local docker containers with bridge network can not communicate with each other. Fixes: c5136b15 ("netfilter: bridge: add and use br_nf_hook_thresh") Signed-off-by:
Artur Molchanov <artur.molchanov@synesis.ru> Acked-by:
Florian Westphal <fw@strlen.de> Signed-off-by:
Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by:
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Jan Kara authored
commit 0a417b8d upstream. Commit 99579cce "xfs: skip dirty pages in ->releasepage()" started to skip dirty pages in xfs_vm_releasepage() which also has the effect that if a dirty page is truncated, it does not get freed by block_invalidatepage() and is lingering in LRU list waiting for reclaim. So a simple loop like: while true; do dd if=/dev/zero of=file bs=1M count=100 rm file done will keep using more and more memory until we hit low watermarks and start pagecache reclaim which will eventually reclaim also the truncate pages. Keeping these truncated (and thus never usable) pages in memory is just a waste of memory, is unnecessarily stressing page cache reclaim, and reportedly also leads to anonymous mmap(2) returning ENOMEM prematurely. So instead of just skipping dirty pages in xfs_vm_releasepage(), return to old behavior of skipping them only if they have delalloc or unwritten buffers and fix the spurious warnings by warning only if the page is clean. CC: Brian Foster <bfoster@redhat.com> CC: Vlastimil Babka <vbabka@suse.cz> Reported-by:
Petr Tůma <petr.tuma@d3s.mff.cuni.cz> Fixes: 99579cceSigned-off-by:
Jan Kara <jack@suse.cz> Reviewed-by:
Brian Foster <bfoster@redhat.com> Signed-off-by:
Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by:
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Geert Uytterhoeven authored
commit 5018ada6 upstream. When removing a gpiochip that uses GPIO hogging (e.g. by unloading the chip's DT overlay), a warning is printed: gpio gpiochip8: REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED This happens because gpiochip_free_hogs() is called after the gdev->chip pointer is reset to NULL. Hence __gpiod_free() cannot determine the chip in use, and cannot clear flags nor call the optional chip-specific .free() callback. Move the call to gpiochip_free_hogs() up to fix this. Fixes: ff2b1359 ("gpio: make the gpiochip a real device") Signed-off-by:
Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by:
Linus Walleij <linus.walleij@linaro.org> Signed-off-by:
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Johannes Berg authored
commit 753aacfd upstream. A single netlink socket might own multiple interfaces *and* a scheduled scan request (which might belong to another interface), so when it goes away both may need to be destroyed. Remove the schedule_scan_stop indirection to fix this - it's only needed for interface destruction because of the way this works right now, with a single work taking care of all interfaces. Fixes: 93a1e86c ("nl80211: Stop scheduled scan if netlink client disappears") Signed-off-by:
Johannes Berg <johannes.berg@intel.com> Signed-off-by:
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Nicolai Stange authored
commit 20b1e22d upstream. With the following commit: 4bc9f92e ("x86/efi-bgrt: Use efi_mem_reserve() to avoid copying image data") ... efi_bgrt_init() calls into the memblock allocator through efi_mem_reserve() => efi_arch_mem_reserve() *after* mm_init() has been called. Indeed, KASAN reports a bad read access later on in efi_free_boot_services(): BUG: KASAN: use-after-free in efi_free_boot_services+0xae/0x24c at addr ffff88022de12740 Read of size 4 by task swapper/0/0 page:ffffea0008b78480 count:0 mapcount:-127 mapping: (null) index:0x1 flags: 0x5fff8000000000() [...] Call Trace: dump_stack+0x68/0x9f kasan_report_error+0x4c8/0x500 kasan_report+0x58/0x60 __asan_load4+0x61/0x80 efi_free_boot_services+0xae/0x24c start_kernel+0x527/0x562 x86_64_start_reservations+0x24/0x26 x86_64_start_kernel+0x157/0x17a start_cpu+0x5/0x14 The instruction at the given address is the first read from the memmap's memory, i.e. the read of md->type in efi_free_boot_services(). Note that the writes earlier in efi_arch_mem_reserve() don't splat because they're done through early_memremap()ed addresses. So, after memblock is gone, allocations should be done through the "normal" page allocator. Introduce a helper, efi_memmap_alloc() for this. Use it from efi_arch_mem_reserve(), efi_free_boot_services() and, for the sake of consistency, from efi_fake_memmap() as well. Note that for the latter, the memmap allocations cease to be page aligned. This isn't needed though. Tested-by:
Dan Williams <dan.j.williams@intel.com> Signed-off-by:
Nicolai Stange <nicstange@gmail.com> Reviewed-by:
Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Dave Young <dyoung@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Mika Penttilä <mika.penttila@nextfour.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Fixes: 4bc9f92e ("x86/efi-bgrt: Use efi_mem_reserve() to avoid copying image data") Link: http://lkml.kernel.org/r/20170105125130.2815-1-nicstange@gmail.comSigned-off-by:
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Peter Jones authored
commit 0100a3e6 upstream. Some machines, such as the Lenovo ThinkPad W541 with firmware GNET80WW (2.28), include memory map entries with phys_addr=0x0 and num_pages=0. These machines fail to boot after the following commit, commit 8e80632f ("efi/esrt: Use efi_mem_reserve() and avoid a kmalloc()") Fix this by removing such bogus entries from the memory map. Furthermore, currently the log output for this case (with efi=debug) looks like: [ 0.000000] efi: mem45: [Reserved | | | | | | | | | | | | ] range=[0x0000000000000000-0xffffffffffffffff] (0MB) This is clearly wrong, and also not as informative as it could be. This patch changes it so that if we find obviously invalid memory map entries, we print an error and skip those entries. It also detects the display of the address range calculation overflow, so the new output is: [ 0.000000] efi: [Firmware Bug]: Invalid EFI memory map entries: [ 0.000000] efi: mem45: [Reserved | | | | | | | | | | | | ] range=[0x0000000000000000-0x0000000000000000] (invalid) It also detects memory map sizes that would overflow the physical address, for example phys_addr=0xfffffffffffff000 and num_pages=0x0200000000000001, and prints: [ 0.000000] efi: [Firmware Bug]: Invalid EFI memory map entries: [ 0.000000] efi: mem45: [Reserved | | | | | | | | | | | | ] range=[phys_addr=0xfffffffffffff000-0x20ffffffffffffffff] (invalid) It then removes these entries from the memory map. Signed-off-by:
Peter Jones <pjones@redhat.com> Signed-off-by:
Matt Fleming <matt@codeblueprint.co.uk> [Matt: Include bugzilla info in commit log] Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://bugzilla.kernel.org/show_bug.cgi?id=191121Signed-off-by:
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Ard Biesheuvel authored
commit abfb7b68 upstream. As reported by James Morse, the current libstub code involving the annotated memory map only works somewhat correctly by accident, due to the fact that a pool allocation happens to be reused immediately, retaining its former contents on most implementations of the UEFI boot services. Instead of juggling memory maps, which makes the code more complex than it needs to be, simply put placeholder values into the FDT for the memory map parameters, and only write the actual values after ExitBootServices() has been called. Reported-by:
James Morse <james.morse@arm.com> Signed-off-by:
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Steve Rutherford authored
commit 129a72a0 upstream. Introduces segemented_write_std. Switches from emulated reads/writes to standard read/writes in fxsave, fxrstor, sgdt, and sidt. This fixes CVE-2017-2584, a longstanding kernel memory leak. Since commit 283c95d0 ("KVM: x86: emulate FXSAVE and FXRSTOR", 2016-11-09), which is luckily not yet in any final release, this would also be an exploitable kernel memory *write*! Reported-by:
Dmitry Vyukov <dvyukov@google.com> Fixes: 96051572 Fixes: 283c95d0Suggested-by:
Paolo Bonzini <pbonzini@redhat.com> Signed-off-by:
Steve Rutherford <srutherford@google.com> Signed-off-by:
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Radim Krčmář authored
commit 283c95d0 upstream. Internal errors were reported on 16 bit fxsave and fxrstor with ipxe. Old Intels don't have unrestricted_guest, so we have to emulate them. The patch takes advantage of the hardware implementation. AMD and Intel differ in saving and restoring other fields in first 32 bytes. A test wrote 0xff to the fxsave area, 0 to upper bits of MCSXR in the fxsave area, executed fxrstor, rewrote the fxsave area to 0xee, and executed fxsave: Intel (Nehalem): 7f 1f 7f 7f ff 00 ff 07 ff ff ff ff ff ff 00 00 ff ff ff ff ff ff 00 00 ff ff 00 00 ff ff 00 00 Intel (Haswell -- deprecated FPU CS and FPU DS): 7f 1f 7f 7f ff 00 ff 07 ff ff ff ff 00 00 00 00 ff ff ff ff 00 00 00 00 ff ff 00 00 ff ff 00 00 AMD (Opteron 2300-series): 7f 1f 7f 7f ff 00 ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee ee ff ff 00 00 ff ff 02 00 fxsave/fxrstor will only be emulated on early Intels, so KVM can't do much to improve the situation. Signed-off-by:
Radim Krčmář <rkrcmar@redhat.com> Signed-off-by:
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Radim Krčmář authored
commit aabba3c6 upstream. Move the existing exception handling for inline assembly into a macro and switch its return values to X86EMUL type. Signed-off-by:
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Radim Krčmář authored
commit d3fe959f upstream. Needed for FXSAVE and FXRSTOR. Signed-off-by:
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Wanpeng Li authored
commit 546d87e5 upstream. Reported by syzkaller: BUG: unable to handle kernel NULL pointer dereference at 00000000000001b0 IP: _raw_spin_lock+0xc/0x30 PGD 3e28eb067 PUD 3f0ac6067 PMD 0 Oops: 0002 [#1] SMP CPU: 0 PID: 2431 Comm: test Tainted: G OE 4.10.0-rc1+ #3 Call Trace: ? kvm_ioapic_scan_entry+0x3e/0x110 [kvm] kvm_arch_vcpu_ioctl_run+0x10a8/0x15f0 [kvm] ? pick_next_task_fair+0xe1/0x4e0 ? kvm_arch_vcpu_load+0xea/0x260 [kvm] kvm_vcpu_ioctl+0x33a/0x600 [kvm] ? hrtimer_try_to_cancel+0x29/0x130 ? do_nanosleep+0x97/0xf0 do_vfs_ioctl+0xa1/0x5d0 ? __hrtimer_init+0x90/0x90 ? do_nanosleep+0x5b/0xf0 SyS_ioctl+0x79/0x90 do_syscall_64+0x6e/0x180 entry_SYSCALL64_slow_path+0x25/0x25 RIP: _raw_spin_lock+0xc/0x30 RSP: ffffa43688973cc0 The syzkaller folks reported a NULL pointer dereference due to ENABLE_CAP succeeding even without an irqchip. The Hyper-V synthetic interrupt controller is activated, resulting in a wrong request to rescan the ioapic and a NULL pointer dereference. #include <sys/ioctl.h> #include <sys/mman.h> #include <sys/types.h> #include <linux/kvm.h> #include <pthread.h> #include <stddef.h> #include <stdint.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #ifndef KVM_CAP_HYPERV_SYNIC #define KVM_CAP_HYPERV_SYNIC 123 #endif void* thr(void* arg) { struct kvm_enable_cap cap; cap.flags = 0; cap.cap = KVM_CAP_HYPERV_SYNIC; ioctl((long)arg, KVM_ENABLE_CAP, &cap); return 0; } int main() { void *host_mem = mmap(0, 0x1000, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); int kvmfd = open("/dev/kvm", 0); int vmfd = ioctl(kvmfd, KVM_CREATE_VM, 0); struct kvm_userspace_memory_region memreg; memreg.slot = 0; memreg.flags = 0; memreg.guest_phys_addr = 0; memreg.memory_size = 0x1000; memreg.userspace_addr = (unsigned long)host_mem; host_mem[0] = 0xf4; ioctl(vmfd, KVM_SET_USER_MEMORY_REGION, &memreg); int cpufd = ioctl(vmfd, KVM_CREATE_VCPU, 0); struct kvm_sregs sregs; ioctl(cpufd, KVM_GET_SREGS, &sregs); sregs.cr0 = 0; sregs.cr4 = 0; sregs.efer = 0; sregs.cs.selector = 0; sregs.cs.base = 0; ioctl(cpufd, KVM_SET_SREGS, &sregs); struct kvm_regs regs = { .rflags = 2 }; ioctl(cpufd, KVM_SET_REGS, ®s); ioctl(vmfd, KVM_CREATE_IRQCHIP, 0); pthread_t th; pthread_create(&th, 0, thr, (void*)(long)cpufd); usleep(rand() % 10000); ioctl(cpufd, KVM_RUN, 0); pthread_join(th, 0); return 0; } This patch fixes it by failing ENABLE_CAP if without an irqchip. Reported-by:
Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by:
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David Matlack authored
commit cef84c30 upstream. KVM's lapic emulation uses static_key_deferred (apic_{hw,sw}_disabled). These are implemented with delayed_work structs which can still be pending when the KVM module is unloaded. We've seen this cause kernel panics when the kvm_intel module is quickly reloaded. Use the new static_key_deferred_flush() API to flush pending updates on module unload. Signed-off-by:
David Matlack <dmatlack@google.com> Signed-off-by:
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David Matlack authored
commit b6416e61 upstream. Modules that use static_key_deferred need a way to synchronize with any delayed work that is still pending when the module is unloaded. Introduce static_key_deferred_flush() which flushes any pending jump label updates. Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by:
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Wanpeng Li authored
commit 4f3dbdf4 upstream. Reported syzkaller: BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 IP: irq_bypass_unregister_consumer+0x9d/0xb70 [irqbypass] PGD 0 Oops: 0002 [#1] SMP CPU: 1 PID: 125 Comm: kworker/1:1 Not tainted 4.9.0+ #1 Workqueue: kvm-irqfd-cleanup irqfd_shutdown [kvm] task: ffff9bbe0dfbb900 task.stack: ffffb61802014000 RIP: 0010:irq_bypass_unregister_consumer+0x9d/0xb70 [irqbypass] Call Trace: irqfd_shutdown+0x66/0xa0 [kvm] process_one_work+0x16b/0x480 worker_thread+0x4b/0x500 kthread+0x101/0x140 ? process_one_work+0x480/0x480 ? kthread_create_on_node+0x60/0x60 ret_from_fork+0x25/0x30 RIP: irq_bypass_unregister_consumer+0x9d/0xb70 [irqbypass] RSP: ffffb61802017e20 CR2: 0000000000000008 The syzkaller folks reported a NULL pointer dereference that due to unregister an consumer which fails registration before. The syzkaller creates two VMs w/ an equal eventfd occasionally. So the second VM fails to register an irqbypass consumer. It will make irqfd as inactive and queue an workqueue work to shutdown irqfd and unregister the irqbypass consumer when eventfd is closed. However, the second consumer has been initialized though it fails registration. So the token(same as the first VM's) is taken to unregister the consumer through the workqueue, the consumer of the first VM is found and unregistered, then NULL deref incurred in the path of deleting consumer from the consumers list. This patch fixes it by making irq_bypass_register/unregister_consumer() looks for the consumer entry based on consumer pointer itself instead of token matching. Reported-by:
Alex Williamson <alex.williamson@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Alex Williamson <alex.williamson@redhat.com> Signed-off-by:
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Paolo Bonzini authored
commit 33ab9110 upstream. This is CVE-2017-2583. On Intel this causes a failed vmentry because SS's type is neither 3 nor 7 (even though the manual says this check is only done for usable SS, and the dmesg splat says that SS is unusable!). On AMD it's worse: svm.c is confused and sets CPL to 0 in the vmcb. The fix fabricates a data segment descriptor when SS is set to a null selector, so that CPL and SS.DPL are set correctly in the VMCS/vmcb. Furthermore, only allow setting SS to a NULL selector if SS.RPL < 3; this in turn ensures CPL < 3 because RPL must be equal to CPL. Thanks to Andy Lutomirski and Willy Tarreau for help in analyzing the bug and deciphering the manuals. Reported-by:
Xiaohan Zhang <zhangxiaohan1@huawei.com> Fixes: 79d5b4c3Signed-off-by:
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Mike Kravetz authored
commit e5bbc8a6 upstream. return_unused_surplus_pages() decrements the global reservation count, and frees any unused surplus pages that were backing the reservation. Commit 7848a4bf ("mm/hugetlb.c: add cond_resched_lock() in return_unused_surplus_pages()") added a call to cond_resched_lock in the loop freeing the pages. As a result, the hugetlb_lock could be dropped, and someone else could use the pages that will be freed in subsequent iterations of the loop. This could result in inconsistent global hugetlb page state, application api failures (such as mmap) failures or application crashes. When dropping the lock in return_unused_surplus_pages, make sure that the global reservation count (resv_huge_pages) remains sufficiently large to prevent someone else from claiming pages about to be freed. Analyzed by Paul Cassella. Fixes: 7848a4bf ("mm/hugetlb.c: add cond_resched_lock() in return_unused_surplus_pages()") Link: http://lkml.kernel.org/r/1483991767-6879-1-git-send-email-mike.kravetz@oracle.comSigned-off-by:
Mike Kravetz <mike.kravetz@oracle.com> Reported-by:
Paul Cassella <cassella@cray.com> Suggested-by:
Michal Hocko <mhocko@kernel.org> Cc: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.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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John Sperbeck authored
commit c4e490cf upstream. This patch fixes a bug in the freelist randomization code. When a high random number is used, the freelist will contain duplicate entries. It will result in different allocations sharing the same chunk. It will result in odd behaviours and crashes. It should be uncommon but it depends on the machines. We saw it happening more often on some machines (every few hours of running tests). Fixes: c7ce4f60 ("mm: SLAB freelist randomization") Link: http://lkml.kernel.org/r/20170103181908.143178-1-thgarnie@google.comSigned-off-by:
John Sperbeck <jsperbeck@google.com> Signed-off-by:
Thomas Garnier <thgarnie@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by:
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Minchan Kim authored
commit f0571429 upstream. During developemnt for zram-swap asynchronous writeback, I found strange corruption of compressed page, resulting in: Modules linked in: zram(E) CPU: 3 PID: 1520 Comm: zramd-1 Tainted: G E 4.8.0-mm1-00320-ge0d4894c9c38-dirty #3274 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 task: ffff88007620b840 task.stack: ffff880078090000 RIP: set_freeobj.part.43+0x1c/0x1f RSP: 0018:ffff880078093ca8 EFLAGS: 00010246 RAX: 0000000000000018 RBX: ffff880076798d88 RCX: ffffffff81c408c8 RDX: 0000000000000018 RSI: 0000000000000000 RDI: 0000000000000246 RBP: ffff880078093cb0 R08: 0000000000000000 R09: 0000000000000000 R10: ffff88005bc43030 R11: 0000000000001df3 R12: ffff880076798d88 R13: 000000000005bc43 R14: ffff88007819d1b8 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff88007e380000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc934048f20 CR3: 0000000077b01000 CR4: 00000000000406e0 Call Trace: obj_malloc+0x22b/0x260 zs_malloc+0x1e4/0x580 zram_bvec_rw+0x4cd/0x830 [zram] page_requests_rw+0x9c/0x130 [zram] zram_thread+0xe6/0x173 [zram] kthread+0xca/0xe0 ret_from_fork+0x25/0x30 With investigation, it reveals currently stable page doesn't support anonymous page. IOW, reuse_swap_page can reuse the page without waiting writeback completion so it can overwrite page zram is compressing. Unfortunately, zram has used per-cpu stream feature from v4.7. It aims for increasing cache hit ratio of scratch buffer for compressing. Downside of that approach is that zram should ask memory space for compressed page in per-cpu context which requires stricted gfp flag which could be failed. If so, it retries to allocate memory space out of per-cpu context so it could get memory this time and compress the data again, copies it to the memory space. In this scenario, zram assumes the data should never be changed but it is not true unless stable page supports. So, If the data is changed under us, zram can make buffer overrun because second compression size could be bigger than one we got in previous trial and blindly, copy bigger size object to smaller buffer which is buffer overrun. The overrun breaks zsmalloc free object chaining so system goes crash like above. I think below is same problem. https://bugzilla.suse.com/show_bug.cgi?id=997574 Unfortunately, reuse_swap_page should be atomic so that we cannot wait on writeback in there so the approach in this patch is simply return false if we found it needs stable page. Although it increases memory footprint temporarily, it happens rarely and it should be reclaimed easily althoug it happened. Also, It would be better than waiting of IO completion, which is critial path for application latency. Fixes: da9556a2 ("zram: user per-cpu compression streams") Link: http://lkml.kernel.org/r/20161120233015.GA14113@bbox Link: http://lkml.kernel.org/r/1482366980-3782-2-git-send-email-minchan@kernel.orgSigned-off-by:
Minchan Kim <minchan@kernel.org> Acked-by:
Hugh Dickins <hughd@google.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: Takashi Iwai <tiwai@suse.de> Cc: Hyeoncheol Lee <cheol.lee@lge.com> Cc: <yjay.kim@lge.com> Cc: Sangseok Lee <sangseok.lee@lge.com> Signed-off-by:
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Michal Hocko authored
commit b4536f0c upstream. Nils Holland and Klaus Ethgen have reported unexpected OOM killer invocations with 32b kernel starting with 4.8 kernels kworker/u4:5 invoked oom-killer: gfp_mask=0x2400840(GFP_NOFS|__GFP_NOFAIL), nodemask=0, order=0, oom_score_adj=0 kworker/u4:5 cpuset=/ mems_allowed=0 CPU: 1 PID: 2603 Comm: kworker/u4:5 Not tainted 4.9.0-gentoo #2 [...] Mem-Info: active_anon:58685 inactive_anon:90 isolated_anon:0 active_file:274324 inactive_file:281962 isolated_file:0 unevictable:0 dirty:649 writeback:0 unstable:0 slab_reclaimable:40662 slab_unreclaimable:17754 mapped:7382 shmem:202 pagetables:351 bounce:0 free:206736 free_pcp:332 free_cma:0 Node 0 active_anon:234740kB inactive_anon:360kB active_file:1097296kB inactive_file:1127848kB unevictable:0kB isolated(anon):0kB isolated(file):0kB mapped:29528kB dirty:2596kB writeback:0kB shmem:0kB shmem_thp: 0kB shmem_pmdmapped: 184320kB anon_thp: 808kB writeback_tmp:0kB unstable:0kB pages_scanned:0 all_unreclaimable? no DMA free:3952kB min:788kB low:984kB high:1180kB active_anon:0kB inactive_anon:0kB active_file:7316kB inactive_file:0kB unevictable:0kB writepending:96kB present:15992kB managed:15916kB mlocked:0kB slab_reclaimable:3200kB slab_unreclaimable:1408kB kernel_stack:0kB pagetables:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB lowmem_reserve[]: 0 813 3474 3474 Normal free:41332kB min:41368kB low:51708kB high:62048kB active_anon:0kB inactive_anon:0kB active_file:532748kB inactive_file:44kB unevictable:0kB writepending:24kB present:897016kB managed:836248kB mlocked:0kB slab_reclaimable:159448kB slab_unreclaimable:69608kB kernel_stack:1112kB pagetables:1404kB bounce:0kB free_pcp:528kB local_pcp:340kB free_cma:0kB lowmem_reserve[]: 0 0 21292 21292 HighMem free:781660kB min:512kB low:34356kB high:68200kB active_anon:234740kB inactive_anon:360kB active_file:557232kB inactive_file:1127804kB unevictable:0kB writepending:2592kB present:2725384kB managed:2725384kB mlocked:0kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:0kB pagetables:0kB bounce:0kB free_pcp:800kB local_pcp:608kB free_cma:0kB the oom killer is clearly pre-mature because there there is still a lot of page cache in the zone Normal which should satisfy this lowmem request. Further debugging has shown that the reclaim cannot make any forward progress because the page cache is hidden in the active list which doesn't get rotated because inactive_list_is_low is not memcg aware. The code simply subtracts per-zone highmem counters from the respective memcg's lru sizes which doesn't make any sense. We can simply end up always seeing the resulting active and inactive counts 0 and return false. This issue is not limited to 32b kernels but in practice the effect on systems without CONFIG_HIGHMEM would be much harder to notice because we do not invoke the OOM killer for allocations requests targeting < ZONE_NORMAL. Fix the issue by tracking per zone lru page counts in mem_cgroup_per_node and subtract per-memcg highmem counts when memcg is enabled. Introduce helper lruvec_zone_lru_size which redirects to either zone counters or mem_cgroup_get_zone_lru_size when appropriate. We are losing empty LRU but non-zero lru size detection introduced by ca707239 ("mm: update_lru_size warn and reset bad lru_size") because of the inherent zone vs. node discrepancy. Fixes: f8d1a311 ("mm: consider whether to decivate based on eligible zones inactive ratio") Link: http://lkml.kernel.org/r/20170104100825.3729-1-mhocko@kernel.orgSigned-off-by:
Michal Hocko <mhocko@suse.com> Reported-by:
Nils Holland <nholland@tisys.org> Tested-by:
Klaus Ethgen <Klaus@Ethgen.de> Acked-by:
Mel Gorman <mgorman@suse.de> Acked-by:
Johannes Weiner <hannes@cmpxchg.org> Reviewed-by:
Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by:
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Eric Ren authored
commit e7ee2c08 upstream. The crash happens rather often when we reset some cluster nodes while nodes contend fiercely to do truncate and append. The crash backtrace is below: dlm: C21CBDA5E0774F4BA5A9D4F317717495: dlm_recover_grant 1 locks on 971 resources dlm: C21CBDA5E0774F4BA5A9D4F317717495: dlm_recover 9 generation 5 done: 4 ms ocfs2: Begin replay journal (node 318952601, slot 2) on device (253,18) ocfs2: End replay journal (node 318952601, slot 2) on device (253,18) ocfs2: Beginning quota recovery on device (253,18) for slot 2 ocfs2: Finishing quota recovery on device (253,18) for slot 2 (truncate,30154,1):ocfs2_truncate_file:470 ERROR: bug expression: le64_to_cpu(fe->i_size) != i_size_read(inode) (truncate,30154,1):ocfs2_truncate_file:470 ERROR: Inode 290321, inode i_size = 732 != di i_size = 937, i_flags = 0x1 ------------[ cut here ]------------ kernel BUG at /usr/src/linux/fs/ocfs2/file.c:470! invalid opcode: 0000 [#1] SMP Modules linked in: ocfs2_stack_user(OEN) ocfs2(OEN) ocfs2_nodemanager ocfs2_stackglue(OEN) quota_tree dlm(OEN) configfs fuse sd_mod iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi af_packet iscsi_ibft iscsi_boot_sysfs softdog xfs libcrc32c ppdev parport_pc pcspkr parport joydev virtio_balloon virtio_net i2c_piix4 acpi_cpufreq button processor ext4 crc16 jbd2 mbcache ata_generic cirrus virtio_blk ata_piix drm_kms_helper ahci syscopyarea libahci sysfillrect sysimgblt fb_sys_fops ttm floppy libata drm virtio_pci virtio_ring uhci_hcd virtio ehci_hcd usbcore serio_raw usb_common sg dm_multipath dm_mod scsi_dh_rdac scsi_dh_emc scsi_dh_alua scsi_mod autofs4 Supported: No, Unsupported modules are loaded CPU: 1 PID: 30154 Comm: truncate Tainted: G OE N 4.4.21-69-default #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.1-0-g4adadbd-20151112_172657-sheep25 04/01/2014 task: ffff88004ff6d240 ti: ffff880074e68000 task.ti: ffff880074e68000 RIP: 0010:[<ffffffffa05c8c30>] [<ffffffffa05c8c30>] ocfs2_truncate_file+0x640/0x6c0 [ocfs2] RSP: 0018:ffff880074e6bd50 EFLAGS: 00010282 RAX: 0000000000000074 RBX: 000000000000029e RCX: 0000000000000000 RDX: 0000000000000001 RSI: 0000000000000246 RDI: 0000000000000246 RBP: ffff880074e6bda8 R08: 000000003675dc7a R09: ffffffff82013414 R10: 0000000000034c50 R11: 0000000000000000 R12: ffff88003aab3448 R13: 00000000000002dc R14: 0000000000046e11 R15: 0000000000000020 FS: 00007f839f965700(0000) GS:ffff88007fc80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 00007f839f97e000 CR3: 0000000036723000 CR4: 00000000000006e0 Call Trace: ocfs2_setattr+0x698/0xa90 [ocfs2] notify_change+0x1ae/0x380 do_truncate+0x5e/0x90 do_sys_ftruncate.constprop.11+0x108/0x160 entry_SYSCALL_64_fastpath+0x12/0x6d Code: 24 28 ba d6 01 00 00 48 c7 c6 30 43 62 a0 8b 41 2c 89 44 24 08 48 8b 41 20 48 c7 c1 78 a3 62 a0 48 89 04 24 31 c0 e8 a0 97 f9 ff <0f> 0b 3d 00 fe ff ff 0f 84 ab fd ff ff 83 f8 fc 0f 84 a2 fd ff RIP [<ffffffffa05c8c30>] ocfs2_truncate_file+0x640/0x6c0 [ocfs2] It's because ocfs2_inode_lock() get us stale LVB in which the i_size is not equal to the disk i_size. We mistakenly trust the LVB because the underlaying fsdlm dlm_lock() doesn't set lkb_sbflags with DLM_SBF_VALNOTVALID properly for us. But, why? The current code tries to downconvert lock without DLM_LKF_VALBLK flag to tell o2cb don't update RSB's LVB if it's a PR->NULL conversion, even if the lock resource type needs LVB. This is not the right way for fsdlm. The fsdlm plugin behaves different on DLM_LKF_VALBLK, it depends on DLM_LKF_VALBLK to decide if we care about the LVB in the LKB. If DLM_LKF_VALBLK is not set, fsdlm will skip recovering RSB's LVB from this lkb and set the right DLM_SBF_VALNOTVALID appropriately when node failure happens. The following diagram briefly illustrates how this crash happens: RSB1 is inode metadata lock resource with LOCK_TYPE_USES_LVB; The 1st round: Node1 Node2 RSB1: PR RSB1(master): NULL->EX ocfs2_downconvert_lock(PR->NULL, set_lvb==0) ocfs2_dlm_lock(no DLM_LKF_VALBLK) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - dlm_lock(no DLM_LKF_VALBLK) convert_lock(overwrite lkb->lkb_exflags with no DLM_LKF_VALBLK) RSB1: NULL RSB1: EX reset Node2 dlm_recover_rsbs() recover_lvb() /* The LVB is not trustable if the node with EX fails and * no lock >= PR is left. We should set RSB_VALNOTVALID for RSB1. */ if(!(kb_exflags & DLM_LKF_VALBLK)) /* This means we miss the chance to return; * to invalid the LVB here. */ The 2nd round: Node 1 Node2 RSB1(become master from recovery) ocfs2_setattr() ocfs2_inode_lock(NULL->EX) /* dlm_lock() return the stale lvb without setting DLM_SBF_VALNOTVALID */ ocfs2_meta_lvb_is_trustable() return 1 /* so we don't refresh inode from disk */ ocfs2_truncate_file() mlog_bug_on_msg(disk isize != i_size_read(inode)) /* crash! */ The fix is quite straightforward. We keep to set DLM_LKF_VALBLK flag for dlm_lock() if the lock resource type needs LVB and the fsdlm plugin is uesed. Link: http://lkml.kernel.org/r/1481275846-6604-1-git-send-email-zren@suse.comSigned-off-by:
Eric Ren <zren@suse.com> Reviewed-by:
Joseph Qi <jiangqi903@gmail.com> Cc: Mark Fasheh <mfasheh@versity.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Signed-off-by:
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Dan Williams authored
commit f931ab47 upstream. Both arch_add_memory() and arch_remove_memory() expect a single threaded context. For example, arch/x86/mm/init_64.c::kernel_physical_mapping_init() does not hold any locks over this check and branch: if (pgd_val(*pgd)) { pud = (pud_t *)pgd_page_vaddr(*pgd); paddr_last = phys_pud_init(pud, __pa(vaddr), __pa(vaddr_end), page_size_mask); continue; } pud = alloc_low_page(); paddr_last = phys_pud_init(pud, __pa(vaddr), __pa(vaddr_end), page_size_mask); The result is that two threads calling devm_memremap_pages() simultaneously can end up colliding on pgd initialization. This leads to crash signatures like the following where the loser of the race initializes the wrong pgd entry: BUG: unable to handle kernel paging request at ffff888ebfff0000 IP: memcpy_erms+0x6/0x10 PGD 2f8e8fc067 PUD 0 /* <---- Invalid PUD */ Oops: 0000 [#1] SMP DEBUG_PAGEALLOC CPU: 54 PID: 3818 Comm: systemd-udevd Not tainted 4.6.7+ #13 task: ffff882fac290040 ti: ffff882f887a4000 task.ti: ffff882f887a4000 RIP: memcpy_erms+0x6/0x10 [..] Call Trace: ? pmem_do_bvec+0x205/0x370 [nd_pmem] ? blk_queue_enter+0x3a/0x280 pmem_rw_page+0x38/0x80 [nd_pmem] bdev_read_page+0x84/0xb0 Hold the standard memory hotplug mutex over calls to arch_{add,remove}_memory(). Fixes: 41e94a85 ("add devm_memremap_pages") Link: http://lkml.kernel.org/r/148357647831.9498.12606007370121652979.stgit@dwillia2-desk3.amr.corp.intel.comSigned-off-by:
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Minchan Kim authored
commit 20f664aa upstream. Andreas reported [1] made a test in jemalloc hang in THP mode in arm64: http://lkml.kernel.org/r/mvmmvfy37g1.fsf@hawking.suse.de The problem is currently page fault handler doesn't supports dirty bit emulation of pmd for non-HW dirty-bit architecture so that application stucks until VM marked the pmd dirty. How the emulation work depends on the architecture. In case of arm64, when it set up pte firstly, it sets pte PTE_RDONLY to get a chance to mark the pte dirty via triggering page fault when store access happens. Once the page fault occurs, VM marks the pmd dirty and arch code for setting pmd will clear PTE_RDONLY for application to proceed. IOW, if VM doesn't mark the pmd dirty, application hangs forever by repeated fault(i.e., store op but the pmd is PTE_RDONLY). This patch enables pmd dirty-bit emulation for those architectures. [1] b8d3c4c3, mm/huge_memory.c: don't split THP page when MADV_FREE syscall is called Fixes: b8d3c4c3 ("mm/huge_memory.c: don't split THP page when MADV_FREE syscall is called") Link: http://lkml.kernel.org/r/1482506098-6149-1-git-send-email-minchan@kernel.orgSigned-off-by:
Andreas Schwab <schwab@suse.de> Tested-by:
Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by:
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Ross Zwisler authored
commit 965d004a upstream. Currently in DAX if we have three read faults on the same hole address we can end up with the following: Thread 0 Thread 1 Thread 2 -------- -------- -------- dax_iomap_fault grab_mapping_entry lock_slot <locks empty DAX entry> dax_iomap_fault grab_mapping_entry get_unlocked_mapping_entry <sleeps on empty DAX entry> dax_iomap_fault grab_mapping_entry get_unlocked_mapping_entry <sleeps on empty DAX entry> dax_load_hole find_or_create_page ... page_cache_tree_insert dax_wake_mapping_entry_waiter <wakes one sleeper> __radix_tree_replace <swaps empty DAX entry with 4k zero page> <wakes> get_page lock_page ... put_locked_mapping_entry unlock_page put_page <sleeps forever on the DAX wait queue> The crux of the problem is that once we insert a 4k zero page, all locking from then on is done in terms of that 4k zero page and any additional threads sleeping on the empty DAX entry will never be woken. Fix this by waking all sleepers when we replace the DAX radix tree entry with a 4k zero page. This will allow all sleeping threads to successfully transition from locking based on the DAX empty entry to locking on the 4k zero page. With the test case reported by Xiong this happens very regularly in my test setup, with some runs resulting in 9+ threads in this deadlocked state. With this fix I've been able to run that same test dozens of times in a loop without issue. Fixes: ac401cc7 ("dax: New fault locking") Link: http://lkml.kernel.org/r/1483479365-13607-1-git-send-email-ross.zwisler@linux.intel.comSigned-off-by:
Ross Zwisler <ross.zwisler@linux.intel.com> Reported-by:
Xiong Zhou <xzhou@redhat.com> Reviewed-by:
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