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a PT page will be released if it doesn't contain any meaningful mappings during PPGTT page table shrinking. The PT entry in the upper level will be set to a scratch entry. Normally this works nicely, but in virtualization world, the PPGTT page table is tracked by hypervisor. Releasing the PT page before modifying the upper level PT entry would cause extra efforts. As the tracked page has been returned to OS before losing track from hypervisor, it could be written in any pattern. Hypervisor has to recognize if a page is still being used as a PT page by validating these writing patterns. It's complicated. Better let the guest modify the PT entry in upper level PT first, then release the PT page. Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Michał Winiarski <michal.winiarski@intel.com> Cc: Michał Winiarski <michal.winiarski@intel.com> Cc: Michel Thierry <michel.thierry@intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Zhenyu Wang <zhenyuw@linux.intel.com> Cc: Zhiyuan Lv <zhiyuan.lv@intel.com> Signed-off-by: Zhi Wang <zhi.a.wang@intel.com> Link: https://patchwork.freedesktop.org/patch/122697/msgid/1479728666-25333-1-git-send-email-zhi.a.wang@intel.com Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Link: http://patchwork.freedesktop.org/patch/msgid/1480402516-22275-1-git-send-email-zhi.a.wang@intel.com
execlist_update_context() will try to update PDPs in a context before a ELSP submission only for full PPGTT mode, while PDPs was populated during context initialization. Now the latter code path is removed. Let execlist_update_context() also cover !FULL_PPGTT mode. Fixes: 3486977 ("drm/i915: check ppgtt validity when init reg state") Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> Cc: Michal Winiarski <michal.winiarski@intel.com> Cc: Michel Thierry <michel.thierry@intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Zhenyu Wang <zhenyuw@linux.intel.com> Cc: Zhiyuan Lv <zhiyuan.lv@intel.com> Signed-off-by: Zhi Wang <zhi.a.wang@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/1486377436-15380-1-git-send-email-zhi.a.wang@intel.com Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
This patch makes PPGTT page table non-shrinkable when using aliasing PPGTT mode. It's just a temporary solution for making GVT-g work. Fixes: 2ce5179 ("drm/i915/gtt: Free unused lower-level page tables") Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> Cc: Michal Winiarski <michal.winiarski@intel.com> Cc: Michel Thierry <michel.thierry@intel.com> Cc: Mika Kuoppala <mika.kuoppala@intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Daniel Vetter <daniel.vetter@intel.com> Cc: Zhenyu Wang <zhenyuw@linux.intel.com> Cc: Zhiyuan Lv <zhiyuan.lv@intel.com> Signed-off-by: Zhi Wang <zhi.a.wang@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/1486559013-25251-2-git-send-email-zhi.a.wang@intel.com Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: <drm-intel-fixes@lists.freedesktop.org> # v4.10-rc1+ Cc: stable@vger.kernel.org Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
The current virtual edid can only support the resolution up to 1024x768. Update the virtual edid so that can support more resoltions. With this new virtual edid, resolution can be up to 1920x1200. V2: add detailed modeline description in edid code comments Signed-off-by: Chuanxiao Dong <chuanxiao.dong@intel.com> Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com> (cherry picked from commit 2c88313)
Previously intel_gvt_init() was called very early even before MMIO initialization which had several drawbacks: - Have to handle MMIO access for initial MMIO state dump if golden state firmware is not available - Hypervisor detection should depend on pvinfo only instead of detecting hypervisor status. - Don't know hw resource size e.g aperture, ggtt size to determine for vGPU type, etc. This trys to move intel_gvt_init() call late after required info has already been initialized for GVT host. Acked-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com> (cherry picked from commit 26f837e)
Prepare to remove detect_host() hook. Move intel iommu detection early in intel_gvt_init(). Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com> (cherry picked from commit d2896e3)
We only depend on pvinfo register for GVT-g state detection, not require hypervisor host detect any more. Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com> (cherry picked from commit 3de49a7)
As now gvt init is late after MMIO initialization, use normal MMIO read function for initial firmware exposure if no available firmware loaded. Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com> (cherry picked from commit 1447302)
As now gvt init after knowing hw resource info, we can determine vGPU type from machine size instead of pre-defined value. Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com> (cherry picked from commit 2d6ceb8)
"caps.buf" is always NULL here and "caps.size" is always zero. The code is a no-op and can be removed. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Remove below unimportant log which is too noisy. 'no current vgpu search from q head' Signed-off-by: Changbin Du <changbin.du@intel.com> Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Remove a redundant end of line in below log. 'will complete workload %p\n, status: %d\n' Signed-off-by: Changbin Du <changbin.du@intel.com> Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Reduce the line of logs in below functions and log friendly. o intel_vgpu_reg_imr_handler o intel_vgpu_reg_master_irq_handler o intel_vgpu_reg_ier_handler o intel_vgpu_reg_iir_handler Signed-off-by: Changbin Du <changbin.du@intel.com> Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
MFN usually refers to "Machine Frame Number" in virtulization world. Currently GVT-g populates the shadow PPGTT/GGTT page table with MFN according to the translation between MFN and Guest PFN. When host IOMMU is enabled, GPU DMA transactions go through the IOMMU, GPU needs an IOVA<->MFN mapping to walk the shadow page table in host main memory. This patch will map a page in IOMMU page table before using it in shadow page table and release the map when a shadow page is going to be freed. Signed-off-by: Zhi Wang <zhi.a.wang@intel.com> Signed-off-by: Chuanxiao Dong <chuanxiao.dong@intel.com> Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
When host i915 iommu enabled, gvt needs to use a mapped pfn in PTE entry So before kvm returns the pfn, map this pfn and return the mapped address which is so called iova. Signed-off-by: Chuanxiao Dong <chuanxiao.dong@intel.com> Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
gvt driver has a check which doesn't allow to use gvt when host gpu iommu is enabled. This check can be removed after enable the iommu support in gvt Signed-off-by: Chuanxiao Dong <chuanxiao.dong@intel.com> Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
In function dispatch_workload(), if it fail before calling intel_gvt_scan_and_shadow_wa_ctx(), the indirect ctx will not be shadowed so no cleaup need. wa_ctx->indirect_ctx.obj indicate whether indirect_ctx is shadowed. The obj is null if it is unshadowed. BUG: unable to handle kernel NULL pointer dereference at 00000000000001a0 IP: complete_execlist_workload+0x2c9/0x3e0 [i915] Oops: 0002 [#1] SMP task: ffff939546d2d880 task.stack: ffffbd9b82ac4000 RIP: 0010:complete_execlist_workload+0x2c9/0x3e0 [i915] RSP: 0018:ffffbd9b82ac7dd8 EFLAGS: 00010202 RAX: 0000000000000000 RBX: ffff9393c725b540 RCX: 0000000000000006 RDX: 0000000000000007 RSI: 0000000000000202 RDI: ffff939559c8dd00 RBP: ffffbd9b82ac7e18 R08: 0000000000000001 R09: 000000000120dd8f R10: 0000000000000000 R11: 000000000120dd8f R12: ffff9393c725b540 R13: ffff9393c725b618 R14: ffffbd9b81f0d000 R15: ffff939520e0e000 FS: 0000000000000000(0000) GS:ffff939559c80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000001a0 CR3: 000000043d664000 CR4: 00000000003426e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: workload_thread+0x312/0xd70 [i915] ? __wake_up_sync+0x20/0x20 ? wake_atomic_t_function+0x60/0x60 kthread+0x101/0x140 Signed-off-by: Changbin Du <changbin.du@intel.com> Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
We need to be careful to only update addr mode for gvt shadow context descriptor but keep other valid config. This fixes GPU hang caused by invalid descriptor submitted for gvt workload. Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
We also need reset vGPU virtual display emulation. Since all vreg has been cleared, we need reset display related vreg to reflect our display setting. Signed-off-by: Changbin Du <changbin.du@intel.com> Cc: Ping Gao <ping.a.gao@intel.com> Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
* Add flip done event support for sprite plane on SKL platform. * Fix bug #1452, "Call Trace:handle_default_event_virt+0xef/0x100 [i915]" while booting up guest. Signed-off-by: Xu Han <xu.han@intel.com> Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
For the inhibit ctx, load all mmio in render mmio list into HW by MMIO write for ctx initialization. For the none-inhibit ctx, only load the render mmio which is not in_context into HW by MMIO write. Skip the MMIO write for in_context mmio as context image will load it. Signed-off-by: Chuanxiao Dong <chuanxiao.dong@intel.com> Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
When doing dma map failed for a pfn, kvmgt should unpin the pfn and return error code to device module driver Signed-off-by: Chuanxiao Dong <chuanxiao.dong@intel.com> Cc: xinda.zhao@intel.com Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
As we switched to memremap for opregion, shouldn't use any __iomem for that, and move to use memcpy instead. This fixed static check errors for: CHECK drivers/gpu/drm/i915//gvt/opregion.c drivers/gpu/drm/i915//gvt/opregion.c:142:31: warning: incorrect type in argument 1 (different address spaces) drivers/gpu/drm/i915//gvt/opregion.c:142:31: expected void *addr drivers/gpu/drm/i915//gvt/opregion.c:142:31: got void [noderef] <asn:2>*opregion_va drivers/gpu/drm/i915//gvt/opregion.c:160:35: warning: incorrect type in assignment (different address spaces) drivers/gpu/drm/i915//gvt/opregion.c:160:35: expected void [noderef] <asn:2>*opregion_va drivers/gpu/drm/i915//gvt/opregion.c:160:35: got void * Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
New failsafe mode is introduced, when we detect guest not supporting GVT-g. In failsafe mode, we will ignore all the MMIO and cfg space read/write from guest. This patch can fix the issue that when guest kernel or graphics driver version is too low, there will be a lot of kernel traces in host. V5: rebased onto latest gvt-staging V4: changed coding style by Zhenyu and Ping's advice V3: modified coding style and error messages according to Zhenyu's comment V2: 1) implemented MMIO/GTT/WP pages read/write logic; 2) used a unified function to enter failsafe mode Signed-off-by: Min He <min.he@intel.com> Signed-off-by: Pei Zhang <pei.zhang@intel.com> Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Lots of reduntant log info will be printed out during GPU reset, including accessing untracked mmio register and fence register, variable disable_warn_untrack is added previously to handle the situation, but the accessing of fence register is ignored in the previously patch, so add it back. Besides, set the variable disable_warn_untrack to the defalut value after GPU reset is finished. Signed-off-by: Zhao, Xinda <xinda.zhao@intel.com> Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Windows guest will notitfy GVT-g to request more resources through g2v interface, when its resources are not enough. This patch is to handle this case and let vgpu enter failsafe mode to avoid too many error messages. Signed-off-by: Min He <min.he@intel.com> Signed-off-by: Pei Zhang <pei.zhang@intel.com> Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Due to the request replay, context switch interrupt may come after gvt free the workload thus can cause a kernel NULL pointer kernel panic. This patch will add a simple check to avoid this for a short term. From long term, gvt workload lifecycle doesn't match with i915 request and need to find a proper way to manage this. v4: simplify the NULL pointer check. v5: add unlikely to optimize. Signed-off-by: Chuanxiao Dong <chuanxiao.dong@intel.com> Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
some registers were missing or treated as BDW only. This patch is to fix it avoid unhandled mmio wanrings v2: update commit message according to zhenyu's comment Signed-off-by: Zhao Yan <yan.y.zhao@intel.com> Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
send_display_send_uevent() sends two environment variable, and the
first one GVT_DISPLAY_READY is set including a new line at the end of
the string; that is obviously superfluous and wrong -- at least, it
*looks* so when you only read the code.
However, it doesn't appear in the actual output by a (supposedly
unexpected) trick. The code uses snprintf() and truncates the string
in size 20 bytes. This makes the string as GVT_DISPLAY_READY=0 or
...=1 including the trailing NUL-letter. That is, the '\n' found in
the format string is always cut off as a result.
Although the code gives the correct result, it is confusing. This
patch addresses it, just removing the superfluous '\n' from the format
string for avoiding further confusion. If the argument "ready" were
not a bool, the size 20 should be corrected as well. But it's a
bool, so we can leave the magic number 20 as is for now.
FWIW, the bug was spotted by a new GCC7 warning:
drivers/gpu/drm/i915/gvt/handlers.c: In function 'pvinfo_mmio_write':
drivers/gpu/drm/i915/gvt/handlers.c:1042:34: error: 'snprintf' output truncated before the last format character [-Werror=format-truncation=]
snprintf(display_ready_str, 20, "GVT_DISPLAY_READY=%d\n", ready);
^~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/i915/gvt/handlers.c:1042:2: note: 'snprintf' output 21 bytes into a destination of size 20
snprintf(display_ready_str, 20, "GVT_DISPLAY_READY=%d\n", ready);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Fixes: 04d348a ("drm/i915/gvt: vGPU display virtualization")
Bugzilla: https://bugzilla.suse.com/show_bug.cgi?id=1025903
Reported-by: Richard Biener <rguenther@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
the value of those registers should be applied to hardware on context restoring Signed-off-by: Zhao Yan <yan.y.zhao@intel.com> Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
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Every kernel build on x86 will result in some output: Setup is 13084 bytes (padded to 13312 bytes). System is 4833 kB CRC 6d35fa35 Kernel: arch/x86/boot/bzImage is ready (#2) This shuts it up, so that 'make -s' is truely silent as long as everything works. Building without '-s' should produce unchanged output. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170719125310.2487451-6-arnd@arndb.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Allocating the crashkernel region outside lowmem causes the kernel to oops while trying to kexec into the new kernel: Loading crashdump kernel... Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = edd70000 [00000000] *pgd=de19e835 Internal error: Oops: 817 [#2] SMP ARM Modules linked in: ... CPU: 0 PID: 689 Comm: sh Not tainted 4.12.0-rc3-next-20170601-04015-gc3a5a20 Hardware name: Generic DRA74X (Flattened Device Tree) task: edb32f00 task.stack: edf18000 PC is at memcpy+0x50/0x330 LR is at 0xe3c34001 pc : [<c04baf30>] lr : [<e3c34001>] psr: 800c0193 sp : edf19c2c ip : 0a000001 fp : c0553170 r10: c055316e r9 : 00000001 r8 : e3130001 r7 : e4903004 r6 : 0a000014 r5 : e3500000 r4 : e59f106c r3 : e59f0074 r2 : ffffffe8 r1 : c010fb88 r0 : 00000000 Flags: Nzcv IRQs off FIQs on Mode SVC_32 ISA ARM Segment none Control: 10c5387d Table: add7006a DAC: 00000051 Process sh (pid: 689, stack limit = 0xedf18218) Stack: (0xedf19c2c to 0xedf1a000) ... [<c04baf30>] (memcpy) from [<c010fae0>] (machine_kexec+0xa8/0x12c) [<c010fae0>] (machine_kexec) from [<c01e4104>] (__crash_kexec+0x5c/0x98) [<c01e4104>] (__crash_kexec) from [<c01e419c>] (crash_kexec+0x5c/0x68) [<c01e419c>] (crash_kexec) from [<c010c5c0>] (die+0x228/0x490) [<c010c5c0>] (die) from [<c011e520>] (__do_kernel_fault.part.0+0x54/0x1e4) [<c011e520>] (__do_kernel_fault.part.0) from [<c082412c>] (do_page_fault+0x1e8/0x400) [<c082412c>] (do_page_fault) from [<c010135c>] (do_DataAbort+0x38/0xb8) [<c010135c>] (do_DataAbort) from [<c0823584>] (__dabt_svc+0x64/0xa0) This is caused by image->control_code_page being a highmem page, so page_address(image->control_code_page) returns NULL. In any case, we don't want the control page to be a highmem page. We already limit the crash kernel region to the top of 32-bit physical memory space. Also limit it to the top of lowmem in physical space. Reported-by: Keerthy <j-keerthy@ti.com> Tested-by: Keerthy <j-keerthy@ti.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
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Aug 9, 2017
Subsystem migration methods shouldn't be called for empty migrations. cgroup_migrate_execute() implements this guarantee by bailing early if there are no source css_sets. This used to be correct before a79a908 ("cgroup: introduce cgroup namespaces"), but no longer since the commit because css_sets can stay pinned without tasks in them. This caused cgroup_migrate_execute() call into cpuset migration methods with an empty cgroup_taskset. cpuset migration methods correctly assume that cgroup_taskset_first() never returns NULL; however, due to the bug, it can, leading to the following oops. Unable to handle kernel paging request for data at address 0x00000960 Faulting instruction address: 0xc0000000001d6868 Oops: Kernel access of bad area, sig: 11 [#1] ... CPU: 14 PID: 16947 Comm: kworker/14:0 Tainted: G W 4.12.0-rc4-next-20170609 #2 Workqueue: events cpuset_hotplug_workfn task: c00000000ca60580 task.stack: c00000000c728000 NIP: c0000000001d6868 LR: c0000000001d6858 CTR: c0000000001d6810 REGS: c00000000c72b720 TRAP: 0300 Tainted: GW (4.12.0-rc4-next-20170609) MSR: 8000000000009033 <SF,EE,ME,IR,DR,RI,LE> CR: 44722422 XER: 20000000 CFAR: c000000000008710 DAR: 0000000000000960 DSISR: 40000000 SOFTE: 1 GPR00: c0000000001d6858 c00000000c72b9a0 c000000001536e00 0000000000000000 GPR04: c00000000c72b9c0 0000000000000000 c00000000c72bad0 c000000766367678 GPR08: c000000766366d10 c00000000c72b958 c000000001736e00 0000000000000000 GPR12: c0000000001d6810 c00000000e749300 c000000000123ef8 c000000775af4180 GPR16: 0000000000000000 0000000000000000 c00000075480e9c0 c00000075480e9e0 GPR20: c00000075480e8c0 0000000000000001 0000000000000000 c00000000c72ba20 GPR24: c00000000c72baa0 c00000000c72bac0 c000000001407248 c00000000c72ba20 GPR28: c00000000141fc80 c00000000c72bac0 c00000000c6bc790 0000000000000000 NIP [c0000000001d6868] cpuset_can_attach+0x58/0x1b0 LR [c0000000001d6858] cpuset_can_attach+0x48/0x1b0 Call Trace: [c00000000c72b9a0] [c0000000001d6858] cpuset_can_attach+0x48/0x1b0 (unreliable) [c00000000c72ba00] [c0000000001cbe80] cgroup_migrate_execute+0xb0/0x450 [c00000000c72ba80] [c0000000001d3754] cgroup_transfer_tasks+0x1c4/0x360 [c00000000c72bba0] [c0000000001d923c] cpuset_hotplug_workfn+0x86c/0xa20 [c00000000c72bca0] [c00000000011aa44] process_one_work+0x1e4/0x580 [c00000000c72bd30] [c00000000011ae78] worker_thread+0x98/0x5c0 [c00000000c72bdc0] [c000000000124058] kthread+0x168/0x1b0 [c00000000c72be30] [c00000000000b2e8] ret_from_kernel_thread+0x5c/0x74 Instruction dump: f821ffa1 7c7d1b78 60000000 60000000 38810020 7fa3eb78 3f42ffed 4bff4c25 60000000 3b5a0448 3d420020 eb610020 <e9230960> 7f43d378 e9290000 f92af200 ---[ end trace dcaaf98fb36d9e64 ]--- This patch fixes the bug by adding an explicit nr_tasks counter to cgroup_taskset and skipping calling the migration methods if the counter is zero. While at it, remove the now spurious check on no source css_sets. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-and-tested-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com> Cc: Roman Gushchin <guro@fb.com> Cc: stable@vger.kernel.org # v4.6+ Fixes: a79a908 ("cgroup: introduce cgroup namespaces") Link: http://lkml.kernel.org/r/1497266622.15415.39.camel@abdul.in.ibm.com
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Aug 9, 2017
Andre Wild reported the following warning: WARNING: CPU: 2 PID: 1205 at kernel/cpu.c:240 lockdep_assert_cpus_held+0x4c/0x60 Modules linked in: CPU: 2 PID: 1205 Comm: bash Not tainted 4.13.0-rc2-00022-gfd2b2c57ec20 #10 Hardware name: IBM 2964 N96 702 (z/VM 6.4.0) task: 00000000701d8100 task.stack: 0000000073594000 Krnl PSW : 0704f00180000000 0000000000145e24 (lockdep_assert_cpus_held+0x4c/0x60) ... Call Trace: lockdep_assert_cpus_held+0x42/0x60) stop_machine_cpuslocked+0x62/0xf0 build_all_zonelists+0x92/0x150 numa_zonelist_order_handler+0x102/0x150 proc_sys_call_handler.isra.12+0xda/0x118 proc_sys_write+0x34/0x48 __vfs_write+0x3c/0x178 vfs_write+0xbc/0x1a0 SyS_write+0x66/0xc0 system_call+0xc4/0x2b0 locks held by bash/1205: #0: (sb_writers#4){.+.+.+}, at: vfs_write+0xa6/0x1a0 #1: (zl_order_mutex){+.+...}, at: numa_zonelist_order_handler+0x44/0x150 #2: (zonelists_mutex){+.+...}, at: numa_zonelist_order_handler+0xf4/0x150 Last Breaking-Event-Address: lockdep_assert_cpus_held+0x48/0x60 This can be easily triggered with e.g. echo n > /proc/sys/vm/numa_zonelist_order In commit 3f906ba ("mm/memory-hotplug: switch locking to a percpu rwsem") memory hotplug locking was changed to fix a potential deadlock. This also switched the stop_machine() invocation within build_all_zonelists() to stop_machine_cpuslocked() which now expects that online cpus are locked when being called. This assumption is not true if build_all_zonelists() is being called from numa_zonelist_order_handler(). In order to fix this simply add a mem_hotplug_begin()/mem_hotplug_done() pair to numa_zonelist_order_handler(). Link: http://lkml.kernel.org/r/20170726111738.38768-1-heiko.carstens@de.ibm.com Fixes: 3f906ba ("mm/memory-hotplug: switch locking to a percpu rwsem") Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reported-by: Andre Wild <wild@linux.vnet.ibm.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This patch fixes a bug associated with iscsit_reset_np_thread() that can occur during parallel configfs rmdir of a single iscsi_np used across multiple iscsi-target instances, that would result in hung task(s) similar to below where configfs rmdir process context was blocked indefinately waiting for iscsi_np->np_restart_comp to finish: [ 6726.112076] INFO: task dcp_proxy_node_:15550 blocked for more than 120 seconds. [ 6726.119440] Tainted: G W O 4.1.26-3321 #2 [ 6726.125045] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 6726.132927] dcp_proxy_node_ D ffff8803f202bc88 0 15550 1 0x00000000 [ 6726.140058] ffff8803f202bc88 ffff88085c64d960 ffff88083b3b1ad0 ffff88087fffeb08 [ 6726.147593] ffff8803f202c000 7fffffffffffffff ffff88083f459c28 ffff88083b3b1ad0 [ 6726.155132] ffff88035373c100 ffff8803f202bca8 ffffffff8168ced2 ffff8803f202bcb8 [ 6726.162667] Call Trace: [ 6726.165150] [<ffffffff8168ced2>] schedule+0x32/0x80 [ 6726.170156] [<ffffffff8168f5b4>] schedule_timeout+0x214/0x290 [ 6726.176030] [<ffffffff810caef2>] ? __send_signal+0x52/0x4a0 [ 6726.181728] [<ffffffff8168d7d6>] wait_for_completion+0x96/0x100 [ 6726.187774] [<ffffffff810e7c80>] ? wake_up_state+0x10/0x10 [ 6726.193395] [<ffffffffa035d6e2>] iscsit_reset_np_thread+0x62/0xe0 [iscsi_target_mod] [ 6726.201278] [<ffffffffa0355d86>] iscsit_tpg_disable_portal_group+0x96/0x190 [iscsi_target_mod] [ 6726.210033] [<ffffffffa0363f7f>] lio_target_tpg_store_enable+0x4f/0xc0 [iscsi_target_mod] [ 6726.218351] [<ffffffff81260c5a>] configfs_write_file+0xaa/0x110 [ 6726.224392] [<ffffffff811ea364>] vfs_write+0xa4/0x1b0 [ 6726.229576] [<ffffffff811eb111>] SyS_write+0x41/0xb0 [ 6726.234659] [<ffffffff8169042e>] system_call_fastpath+0x12/0x71 It would happen because each iscsit_reset_np_thread() sets state to ISCSI_NP_THREAD_RESET, sends SIGINT, and then blocks waiting for completion on iscsi_np->np_restart_comp. However, if iscsi_np was active processing a login request and more than a single iscsit_reset_np_thread() caller to the same iscsi_np was blocked on iscsi_np->np_restart_comp, iscsi_np kthread process context in __iscsi_target_login_thread() would flush pending signals and only perform a single completion of np->np_restart_comp before going back to sleep within transport specific iscsit_transport->iscsi_accept_np code. To address this bug, add a iscsi_np->np_reset_count and update __iscsi_target_login_thread() to keep completing np->np_restart_comp until ->np_reset_count has reached zero. Reported-by: Gary Guo <ghg@datera.io> Tested-by: Gary Guo <ghg@datera.io> Cc: Mike Christie <mchristi@redhat.com> Cc: Hannes Reinecke <hare@suse.de> Cc: stable@vger.kernel.org # 3.10+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
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Dean Jenkins says: ==================== asix: Improve robustness Please consider taking these patches to improve the robustness of the ASIX USB to Ethernet driver. Failures prompting an ASIX driver code review ============================================= On an ARM i.MX6 embedded platform some strange one-off and two-off failures were observed in and around the ASIX USB to Ethernet driver. This was observed on a highly modified kernel 3.14 with the ASIX driver containing back-ported changes from kernel.org up to kernel 4.8 approximately. a) A one-off failure in asix_rx_fixup_internal(): There was an occurrence of an attempt to write off the end of the netdev buffer which was trapped by skb_over_panic() in skb_put(). [20030.846440] skbuff: skb_over_panic: text:7f2271c0 len:120 put:60 head:8366ecc0 data:8366ed02 tail:0x8366ed7a end:0x8366ed40 dev:eth0 [20030.863007] Kernel BUG at 8044ce38 [verbose debug info unavailable] [20031.215345] Backtrace: [20031.217884] [<8044cde0>] (skb_panic) from [<8044d50c>] (skb_put+0x50/0x5c) [20031.227408] [<8044d4bc>] (skb_put) from [<7f2271c0>] (asix_rx_fixup_internal+0x1c4/0x23c [asix]) [20031.242024] [<7f226ffc>] (asix_rx_fixup_internal [asix]) from [<7f22724c>] (asix_rx_fixup_common+0x14/0x18 [asix]) [20031.260309] [<7f227238>] (asix_rx_fixup_common [asix]) from [<7f21f7d4>] (usbnet_bh+0x74/0x224 [usbnet]) [20031.269879] [<7f21f760>] (usbnet_bh [usbnet]) from [<8002f834>] (call_timer_fn+0xa4/0x1f0) [20031.283961] [<8002f790>] (call_timer_fn) from [<80030834>] (run_timer_softirq+0x230/0x2a8) [20031.302782] [<80030604>] (run_timer_softirq) from [<80028780>] (__do_softirq+0x15c/0x37c) [20031.321511] [<80028624>] (__do_softirq) from [<80028c38>] (irq_exit+0x8c/0xe8) [20031.339298] [<80028bac>] (irq_exit) from [<8000e9c8>] (handle_IRQ+0x8c/0xc8) [20031.350038] [<8000e93c>] (handle_IRQ) from [<800085c8>] (gic_handle_irq+0xb8/0xf8) [20031.365528] [<80008510>] (gic_handle_irq) from [<8050de80>] (__irq_svc+0x40/0x70) Analysis of the logic of the ASIX driver (containing backported changes from kernel.org up to kernel 4.8 approximately) suggested that the software could not trigger skb_over_panic(). The analysis of the kernel BUG() crash information suggested that the netdev buffer was written with 2 minimal 60 octet length Ethernet frames (ASIX hardware drops the 4 octet FCS field) and the 2nd Ethernet frame attempted to write off the end of the netdev buffer. Note that the netdev buffer should only contain 1 Ethernet frame so if an attempt to write 2 Ethernet frames into the buffer is made then that is wrong. However, the logic of the asix_rx_fixup_internal() only allows 1 Ethernet frame to be written into the netdev buffer. Potentially this failure was due to memory corruption because it was only seen once. b) Two-off failures in the NAPI layer's backlog queue: There were 2 crashes in the NAPI layer's backlog queue presumably after asix_rx_fixup_internal() called usbnet_skb_return(). [24097.273945] Unable to handle kernel NULL pointer dereference at virtual address 00000004 [24097.398944] PC is at process_backlog+0x80/0x16c [24097.569466] Backtrace: [24097.572007] [<8045ad98>] (process_backlog) from [<8045b64c>] (net_rx_action+0xcc/0x248) [24097.591631] [<8045b580>] (net_rx_action) from [<80028780>] (__do_softirq+0x15c/0x37c) [24097.610022] [<80028624>] (__do_softirq) from [<800289cc>] (run_ksoftirqd+0x2c/0x84) and [ 1059.828452] Unable to handle kernel NULL pointer dereference at virtual address 00000000 [ 1059.953715] PC is at process_backlog+0x84/0x16c [ 1060.140896] Backtrace: [ 1060.143434] [<8045ad98>] (process_backlog) from [<8045b64c>] (net_rx_action+0xcc/0x248) [ 1060.163075] [<8045b580>] (net_rx_action) from [<80028780>] (__do_softirq+0x15c/0x37c) [ 1060.181474] [<80028624>] (__do_softirq) from [<80028c38>] (irq_exit+0x8c/0xe8) [ 1060.199256] [<80028bac>] (irq_exit) from [<8000e9c8>] (handle_IRQ+0x8c/0xc8) [ 1060.210006] [<8000e93c>] (handle_IRQ) from [<800085c8>] (gic_handle_irq+0xb8/0xf8) [ 1060.225492] [<80008510>] (gic_handle_irq) from [<8050de80>] (__irq_svc+0x40/0x70) The embedded board was only using an ASIX USB to Ethernet adaptor eth0. Analysis suggested that the doubly-linked list pointers of the backlog queue had been corrupted because one of the link pointers was NULL. Potentially this failure was due to memory corruption because it was only seen twice. Results of the ASIX driver code review ====================================== During the code review some weaknesses were observed in the ASIX driver and the following patches have been created to improve the robustness. Brief overview of the patches ----------------------------- 1. asix: Add rx->ax_skb = NULL after usbnet_skb_return() The current ASIX driver sends the received Ethernet frame to the NAPI layer of the network stack via the call to usbnet_skb_return() in asix_rx_fixup_internal() but retains the rx->ax_skb pointer to the netdev buffer. The driver no longer needs the rx->ax_skb pointer at this point because the NAPI layer now has the Ethernet frame. This means that asix_rx_fixup_internal() must not use rx->ax_skb after the call to usbnet_skb_return() because it could corrupt the handling of the Ethernet frame within the network layer. Therefore, to remove the risk of erroneous usage of rx->ax_skb, set rx->ax_skb to NULL after the call to usbnet_skb_return(). This avoids potential erroneous freeing of rx->ax_skb and erroneous writing to the netdev buffer. If the software now somehow inappropriately reused rx->ax_skb, then a NULL pointer dereference of rx->ax_skb would occur which makes investigation easier. 2. asix: Ensure asix_rx_fixup_info members are all reset This patch creates reset_asix_rx_fixup_info() to allow all the asix_rx_fixup_info structure members to be consistently reset to initial conditions. Call reset_asix_rx_fixup_info() upon each detectable error condition so that the next URB is processed from a known state. Otherwise, there is a risk that some members of the asix_rx_fixup_info structure may be incorrect after an error occurred so potentially leading to a malfunction. 3. asix: Fix small memory leak in ax88772_unbind() This patch creates asix_rx_fixup_common_free() to allow the rx->ax_skb to be freed when necessary. asix_rx_fixup_common_free() is called from ax88772_unbind() before the parent private data structure is freed. Without this patch, there is a risk of a small netdev buffer memory leak each time ax88772_unbind() is called during the reception of an Ethernet frame that spans across 2 URBs. Testing ======= The patches have been sanity tested on a 64-bit Linux laptop running kernel 4.13-rc2 with the 3 patches applied on top. The ASIX USB to Adaptor used for testing was (output of lsusb): ID 0b95:772b ASIX Electronics Corp. AX88772B Test #1 ------- The test ran a flood ping test script which slowly incremented the ICMP Echo Request's payload from 0 to 5000 octets. This eventually causes IPv4 fragmentation to occur which causes Ethernet frames to be sent very close to each other so increases the probability that an Ethernet frame will span 2 URBs. The test showed that all pings were successful. The test took about 15 minutes to complete. Test #2 ------- A script was run on the laptop to periodically run ifdown and ifup every second so that the ASIX USB to Adaptor was up for 1 second and down for 1 second. From a Linux PC connected to the laptop, the following ping command was used ping -f -s 5000 <ip address of laptop> The large ICMP payload causes IPv4 fragmentation resulting in multiple Ethernet frames per original IP packet. Kernel debug within the ASIX driver was enabled to see whether any ASIX errors were generated. The test was run for about 24 hours and no ASIX errors were seen. Patches ======= The 3 patches have been rebased off the net-next repo master branch with HEAD fbbeefd net: fec: Allow reception of frames bigger than 1522 bytes ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
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MEI device performs link reset during system suspend sequence. The link reset cannot be performed while device is in runtime suspend state. The resume sequence is bypassed with suspend direct complete optimization,so the optimization should be disabled for mei devices. Fixes: [ 192.940537] Restarting tasks ... [ 192.940610] PGI is not set [ 192.940619] ------------[ cut here ]------------ [ 192.940623] WARNING: CPU: 0 me.c:653 mei_me_pg_exit_sync+0x351/0x360 [ 192.940624] Modules linked in: [ 192.940627] CPU: 0 PID: 1661 Comm: kworker/0:3 Not tainted 4.13.0-rc2+ #2 [ 192.940628] Hardware name: Dell Inc. XPS 13 9343/0TM99H, BIOS A11 12/08/2016 [ 192.940630] Workqueue: pm pm_runtime_work <snip> [ 192.940642] Call Trace: [ 192.940646] ? pci_pme_active+0x1de/0x1f0 [ 192.940649] ? pci_restore_standard_config+0x50/0x50 [ 192.940651] ? kfree+0x172/0x190 [ 192.940653] ? kfree+0x172/0x190 [ 192.940655] ? pci_restore_standard_config+0x50/0x50 [ 192.940663] mei_me_pm_runtime_resume+0x3f/0xc0 [ 192.940665] pci_pm_runtime_resume+0x7a/0xa0 [ 192.940667] __rpm_callback+0xb9/0x1e0 [ 192.940668] ? preempt_count_add+0x6d/0xc0 [ 192.940670] rpm_callback+0x24/0x90 [ 192.940672] ? pci_restore_standard_config+0x50/0x50 [ 192.940674] rpm_resume+0x4e8/0x800 [ 192.940676] pm_runtime_work+0x55/0xb0 [ 192.940678] process_one_work+0x184/0x3e0 [ 192.940680] worker_thread+0x4d/0x3a0 [ 192.940681] ? preempt_count_sub+0x9b/0x100 [ 192.940683] kthread+0x122/0x140 [ 192.940684] ? process_one_work+0x3e0/0x3e0 [ 192.940685] ? __kthread_create_on_node+0x1a0/0x1a0 [ 192.940688] ret_from_fork+0x27/0x40 [ 192.940690] Code: 96 3a 9e ff 48 8b 7d 98 e8 cd 21 58 00 83 bb bc 01 00 00 04 0f 85 40 fe ff ff e9 41 fe ff ff 48 c7 c7 5f 04 99 96 e8 93 6b 9f ff <0f> ff e9 5d fd ff ff e8 33 fe 99 ff 0f 1f 00 0f 1f 44 00 00 55 [ 192.940719] ---[ end trace a86955597774ead8 ]--- [ 192.942540] done. Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reported-by: Dominik Brodowski <linux@dominikbrodowski.net> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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pfkey_broadcast() might be called from non process contexts, we can not use GFP_KERNEL in these cases [1]. This patch partially reverts commit ba51b6b ("net: Fix RCU splat in af_key"), only keeping the GFP_ATOMIC forcing under rcu_read_lock() section. [1] : syzkaller reported : in_atomic(): 1, irqs_disabled(): 0, pid: 2932, name: syzkaller183439 3 locks held by syzkaller183439/2932: #0: (&net->xfrm.xfrm_cfg_mutex){+.+.+.}, at: [<ffffffff83b43888>] pfkey_sendmsg+0x4c8/0x9f0 net/key/af_key.c:3649 #1: (&pfk->dump_lock){+.+.+.}, at: [<ffffffff83b467f6>] pfkey_do_dump+0x76/0x3f0 net/key/af_key.c:293 #2: (&(&net->xfrm.xfrm_policy_lock)->rlock){+...+.}, at: [<ffffffff83957632>] spin_lock_bh include/linux/spinlock.h:304 [inline] #2: (&(&net->xfrm.xfrm_policy_lock)->rlock){+...+.}, at: [<ffffffff83957632>] xfrm_policy_walk+0x192/0xa30 net/xfrm/xfrm_policy.c:1028 CPU: 0 PID: 2932 Comm: syzkaller183439 Not tainted 4.13.0-rc4+ #24 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 ___might_sleep+0x2b2/0x470 kernel/sched/core.c:5994 __might_sleep+0x95/0x190 kernel/sched/core.c:5947 slab_pre_alloc_hook mm/slab.h:416 [inline] slab_alloc mm/slab.c:3383 [inline] kmem_cache_alloc+0x24b/0x6e0 mm/slab.c:3559 skb_clone+0x1a0/0x400 net/core/skbuff.c:1037 pfkey_broadcast_one+0x4b2/0x6f0 net/key/af_key.c:207 pfkey_broadcast+0x4ba/0x770 net/key/af_key.c:281 dump_sp+0x3d6/0x500 net/key/af_key.c:2685 xfrm_policy_walk+0x2f1/0xa30 net/xfrm/xfrm_policy.c:1042 pfkey_dump_sp+0x42/0x50 net/key/af_key.c:2695 pfkey_do_dump+0xaa/0x3f0 net/key/af_key.c:299 pfkey_spddump+0x1a0/0x210 net/key/af_key.c:2722 pfkey_process+0x606/0x710 net/key/af_key.c:2814 pfkey_sendmsg+0x4d6/0x9f0 net/key/af_key.c:3650 sock_sendmsg_nosec net/socket.c:633 [inline] sock_sendmsg+0xca/0x110 net/socket.c:643 ___sys_sendmsg+0x755/0x890 net/socket.c:2035 __sys_sendmsg+0xe5/0x210 net/socket.c:2069 SYSC_sendmsg net/socket.c:2080 [inline] SyS_sendmsg+0x2d/0x50 net/socket.c:2076 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x445d79 RSP: 002b:00007f32447c1dc8 EFLAGS: 00000202 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000445d79 RDX: 0000000000000000 RSI: 000000002023dfc8 RDI: 0000000000000008 RBP: 0000000000000086 R08: 00007f32447c2700 R09: 00007f32447c2700 R10: 00007f32447c2700 R11: 0000000000000202 R12: 0000000000000000 R13: 00007ffe33edec4f R14: 00007f32447c29c0 R15: 0000000000000000 Fixes: ba51b6b ("net: Fix RCU splat in af_key") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: David Ahern <dsa@cumulusnetworks.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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syzkaller reported that DCCP could have a non empty write queue at dismantle time. WARNING: CPU: 1 PID: 2953 at net/core/stream.c:199 sk_stream_kill_queues+0x3ce/0x520 net/core/stream.c:199 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 2953 Comm: syz-executor0 Not tainted 4.13.0-rc4+ #2 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 panic+0x1e4/0x417 kernel/panic.c:180 __warn+0x1c4/0x1d9 kernel/panic.c:541 report_bug+0x211/0x2d0 lib/bug.c:183 fixup_bug+0x40/0x90 arch/x86/kernel/traps.c:190 do_trap_no_signal arch/x86/kernel/traps.c:224 [inline] do_trap+0x260/0x390 arch/x86/kernel/traps.c:273 do_error_trap+0x120/0x390 arch/x86/kernel/traps.c:310 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:323 invalid_op+0x1e/0x30 arch/x86/entry/entry_64.S:846 RIP: 0010:sk_stream_kill_queues+0x3ce/0x520 net/core/stream.c:199 RSP: 0018:ffff8801d182f108 EFLAGS: 00010297 RAX: ffff8801d1144140 RBX: ffff8801d13cb280 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff85137b00 RDI: ffff8801d13cb280 RBP: ffff8801d182f148 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801d13cb4d0 R13: ffff8801d13cb3b8 R14: ffff8801d13cb300 R15: ffff8801d13cb3b8 inet_csk_destroy_sock+0x175/0x3f0 net/ipv4/inet_connection_sock.c:835 dccp_close+0x84d/0xc10 net/dccp/proto.c:1067 inet_release+0xed/0x1c0 net/ipv4/af_inet.c:425 sock_release+0x8d/0x1e0 net/socket.c:597 sock_close+0x16/0x20 net/socket.c:1126 __fput+0x327/0x7e0 fs/file_table.c:210 ____fput+0x15/0x20 fs/file_table.c:246 task_work_run+0x18a/0x260 kernel/task_work.c:116 exit_task_work include/linux/task_work.h:21 [inline] do_exit+0xa32/0x1b10 kernel/exit.c:865 do_group_exit+0x149/0x400 kernel/exit.c:969 get_signal+0x7e8/0x17e0 kernel/signal.c:2330 do_signal+0x94/0x1ee0 arch/x86/kernel/signal.c:808 exit_to_usermode_loop+0x21c/0x2d0 arch/x86/entry/common.c:157 prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline] syscall_return_slowpath+0x3a7/0x450 arch/x86/entry/common.c:263 Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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The inode is not locked in init_xattrs when creating a new inode. Without this patch, there will occurs assert when booting or creating a new file, if the kernel config CONFIG_SECURITY_SMACK is enabled. Log likes: UBIFS assert failed in ubifs_xattr_set at 298 (pid 1156) CPU: 1 PID: 1156 Comm: ldconfig Tainted: G S 4.12.0-rc1-207440-g1e70b02 #2 Hardware name: MediaTek MT2712 evaluation board (DT) Call trace: [<ffff000008088538>] dump_backtrace+0x0/0x238 [<ffff000008088834>] show_stack+0x14/0x20 [<ffff0000083d98d4>] dump_stack+0x9c/0xc0 [<ffff00000835d524>] ubifs_xattr_set+0x374/0x5e0 [<ffff00000835d7ec>] init_xattrs+0x5c/0xb8 [<ffff000008385788>] security_inode_init_security+0x110/0x190 [<ffff00000835e058>] ubifs_init_security+0x30/0x68 [<ffff00000833ada0>] ubifs_mkdir+0x100/0x200 [<ffff00000820669c>] vfs_mkdir+0x11c/0x1b8 [<ffff00000820b73c>] SyS_mkdirat+0x74/0xd0 [<ffff000008082f8c>] __sys_trace_return+0x0/0x4 Signed-off-by: Xiaolei Li <xiaolei.li@mediatek.com> Signed-off-by: Richard Weinberger <richard@nod.at>
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Aug 29, 2017
The following commit: 39a0526 ("x86/mm: Factor out LDT init from context init") renamed init_new_context() to init_new_context_ldt() and added a new init_new_context() which calls init_new_context_ldt(). However, the error code of init_new_context_ldt() was ignored. Consequently, if a memory allocation in alloc_ldt_struct() failed during a fork(), the ->context.ldt of the new task remained the same as that of the old task (due to the memcpy() in dup_mm()). ldt_struct's are not intended to be shared, so a use-after-free occurred after one task exited. Fix the bug by making init_new_context() pass through the error code of init_new_context_ldt(). This bug was found by syzkaller, which encountered the following splat: BUG: KASAN: use-after-free in free_ldt_struct.part.2+0x10a/0x150 arch/x86/kernel/ldt.c:116 Read of size 4 at addr ffff88006d2cb7c8 by task kworker/u9:0/3710 CPU: 1 PID: 3710 Comm: kworker/u9:0 Not tainted 4.13.0-rc4-next-20170811 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 print_address_description+0x73/0x250 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report+0x24e/0x340 mm/kasan/report.c:409 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:429 free_ldt_struct.part.2+0x10a/0x150 arch/x86/kernel/ldt.c:116 free_ldt_struct arch/x86/kernel/ldt.c:173 [inline] destroy_context_ldt+0x60/0x80 arch/x86/kernel/ldt.c:171 destroy_context arch/x86/include/asm/mmu_context.h:157 [inline] __mmdrop+0xe9/0x530 kernel/fork.c:889 mmdrop include/linux/sched/mm.h:42 [inline] exec_mmap fs/exec.c:1061 [inline] flush_old_exec+0x173c/0x1ff0 fs/exec.c:1291 load_elf_binary+0x81f/0x4ba0 fs/binfmt_elf.c:855 search_binary_handler+0x142/0x6b0 fs/exec.c:1652 exec_binprm fs/exec.c:1694 [inline] do_execveat_common.isra.33+0x1746/0x22e0 fs/exec.c:1816 do_execve+0x31/0x40 fs/exec.c:1860 call_usermodehelper_exec_async+0x457/0x8f0 kernel/umh.c:100 ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431 Allocated by task 3700: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551 kmem_cache_alloc_trace+0x136/0x750 mm/slab.c:3627 kmalloc include/linux/slab.h:493 [inline] alloc_ldt_struct+0x52/0x140 arch/x86/kernel/ldt.c:67 write_ldt+0x7b7/0xab0 arch/x86/kernel/ldt.c:277 sys_modify_ldt+0x1ef/0x240 arch/x86/kernel/ldt.c:307 entry_SYSCALL_64_fastpath+0x1f/0xbe Freed by task 3700: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3503 [inline] kfree+0xca/0x250 mm/slab.c:3820 free_ldt_struct.part.2+0xdd/0x150 arch/x86/kernel/ldt.c:121 free_ldt_struct arch/x86/kernel/ldt.c:173 [inline] destroy_context_ldt+0x60/0x80 arch/x86/kernel/ldt.c:171 destroy_context arch/x86/include/asm/mmu_context.h:157 [inline] __mmdrop+0xe9/0x530 kernel/fork.c:889 mmdrop include/linux/sched/mm.h:42 [inline] __mmput kernel/fork.c:916 [inline] mmput+0x541/0x6e0 kernel/fork.c:927 copy_process.part.36+0x22e1/0x4af0 kernel/fork.c:1931 copy_process kernel/fork.c:1546 [inline] _do_fork+0x1ef/0xfb0 kernel/fork.c:2025 SYSC_clone kernel/fork.c:2135 [inline] SyS_clone+0x37/0x50 kernel/fork.c:2129 do_syscall_64+0x26c/0x8c0 arch/x86/entry/common.c:287 return_from_SYSCALL_64+0x0/0x7a Here is a C reproducer: #include <asm/ldt.h> #include <pthread.h> #include <signal.h> #include <stdlib.h> #include <sys/syscall.h> #include <sys/wait.h> #include <unistd.h> static void *fork_thread(void *_arg) { fork(); } int main(void) { struct user_desc desc = { .entry_number = 8191 }; syscall(__NR_modify_ldt, 1, &desc, sizeof(desc)); for (;;) { if (fork() == 0) { pthread_t t; srand(getpid()); pthread_create(&t, NULL, fork_thread, NULL); usleep(rand() % 10000); syscall(__NR_exit_group, 0); } wait(NULL); } } Note: the reproducer takes advantage of the fact that alloc_ldt_struct() may use vmalloc() to allocate a large ->entries array, and after commit: 5d17a73 ("vmalloc: back off when the current task is killed") it is possible for userspace to fail a task's vmalloc() by sending a fatal signal, e.g. via exit_group(). It would be more difficult to reproduce this bug on kernels without that commit. This bug only affected kernels with CONFIG_MODIFY_LDT_SYSCALL=y. Signed-off-by: Eric Biggers <ebiggers@google.com> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: <stable@vger.kernel.org> [v4.6+] Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Fixes: 39a0526 ("x86/mm: Factor out LDT init from context init") Link: http://lkml.kernel.org/r/20170824175029.76040-1-ebiggers3@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Guillaume Nault says: ==================== l2tp: fix some races in session deletion L2TP provides several interfaces for deleting sessions. Using two of them concurrently can lead to use-after-free bugs. Patch #2 uses a flag to prevent double removal of L2TP sessions. Patch #1 fixes a bug found in the way. Fixing this bug is also necessary for patch #2 to handle all cases. This issue is similar to the tunnel deletion bug being worked on by Sabrina: https://patchwork.ozlabs.org/patch/814173/ ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
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The following lockdep splat has been noticed during LTP testing ====================================================== WARNING: possible circular locking dependency detected 4.13.0-rc3-next-20170807 #12 Not tainted ------------------------------------------------------ a.out/4771 is trying to acquire lock: (cpu_hotplug_lock.rw_sem){++++++}, at: [<ffffffff812b4668>] drain_all_stock.part.35+0x18/0x140 but task is already holding lock: (&mm->mmap_sem){++++++}, at: [<ffffffff8106eb35>] __do_page_fault+0x175/0x530 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&mm->mmap_sem){++++++}: lock_acquire+0xc9/0x230 __might_fault+0x70/0xa0 _copy_to_user+0x23/0x70 filldir+0xa7/0x110 xfs_dir2_sf_getdents.isra.10+0x20c/0x2c0 [xfs] xfs_readdir+0x1fa/0x2c0 [xfs] xfs_file_readdir+0x30/0x40 [xfs] iterate_dir+0x17a/0x1a0 SyS_getdents+0xb0/0x160 entry_SYSCALL_64_fastpath+0x1f/0xbe -> #2 (&type->i_mutex_dir_key#3){++++++}: lock_acquire+0xc9/0x230 down_read+0x51/0xb0 lookup_slow+0xde/0x210 walk_component+0x160/0x250 link_path_walk+0x1a6/0x610 path_openat+0xe4/0xd50 do_filp_open+0x91/0x100 file_open_name+0xf5/0x130 filp_open+0x33/0x50 kernel_read_file_from_path+0x39/0x80 _request_firmware+0x39f/0x880 request_firmware_direct+0x37/0x50 request_microcode_fw+0x64/0xe0 reload_store+0xf7/0x180 dev_attr_store+0x18/0x30 sysfs_kf_write+0x44/0x60 kernfs_fop_write+0x113/0x1a0 __vfs_write+0x37/0x170 vfs_write+0xc7/0x1c0 SyS_write+0x58/0xc0 do_syscall_64+0x6c/0x1f0 return_from_SYSCALL_64+0x0/0x7a -> #1 (microcode_mutex){+.+.+.}: lock_acquire+0xc9/0x230 __mutex_lock+0x88/0x960 mutex_lock_nested+0x1b/0x20 microcode_init+0xbb/0x208 do_one_initcall+0x51/0x1a9 kernel_init_freeable+0x208/0x2a7 kernel_init+0xe/0x104 ret_from_fork+0x2a/0x40 -> #0 (cpu_hotplug_lock.rw_sem){++++++}: __lock_acquire+0x153c/0x1550 lock_acquire+0xc9/0x230 cpus_read_lock+0x4b/0x90 drain_all_stock.part.35+0x18/0x140 try_charge+0x3ab/0x6e0 mem_cgroup_try_charge+0x7f/0x2c0 shmem_getpage_gfp+0x25f/0x1050 shmem_fault+0x96/0x200 __do_fault+0x1e/0xa0 __handle_mm_fault+0x9c3/0xe00 handle_mm_fault+0x16e/0x380 __do_page_fault+0x24a/0x530 do_page_fault+0x30/0x80 page_fault+0x28/0x30 other info that might help us debug this: Chain exists of: cpu_hotplug_lock.rw_sem --> &type->i_mutex_dir_key#3 --> &mm->mmap_sem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&mm->mmap_sem); lock(&type->i_mutex_dir_key#3); lock(&mm->mmap_sem); lock(cpu_hotplug_lock.rw_sem); *** DEADLOCK *** 2 locks held by a.out/4771: #0: (&mm->mmap_sem){++++++}, at: [<ffffffff8106eb35>] __do_page_fault+0x175/0x530 #1: (percpu_charge_mutex){+.+...}, at: [<ffffffff812b4c97>] try_charge+0x397/0x6e0 The problem is very similar to the one fixed by commit a459eeb ("mm, page_alloc: do not depend on cpu hotplug locks inside the allocator"). We are taking hotplug locks while we can be sitting on top of basically arbitrary locks. This just calls for problems. We can get rid of {get,put}_online_cpus, fortunately. We do not have to be worried about races with memory hotplug because drain_local_stock, which is called from both the WQ draining and the memory hotplug contexts, is always operating on the local cpu stock with IRQs disabled. The only thing to be careful about is that the target memcg doesn't vanish while we are still in drain_all_stock so take a reference on it. Link: http://lkml.kernel.org/r/20170913090023.28322-1-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Artem Savkov <asavkov@redhat.com> Tested-by: Artem Savkov <asavkov@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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printk_ratelimit() invokes ___ratelimit() which may invoke a normal
printk() (pr_warn() in this particular case) to warn about suppressed
output. Given that printk_ratelimit() may be called from anywhere, that
pr_warn() is dangerous - it may end up deadlocking the system. Fix
___ratelimit() by using deferred printk().
Sasha reported the following lockdep error:
: Unregister pv shared memory for cpu 8
: select_fallback_rq: 3 callbacks suppressed
: process 8583 (trinity-c78) no longer affine to cpu8
:
: ======================================================
: WARNING: possible circular locking dependency detected
: 4.14.0-rc2-next-20170927+ #252 Not tainted
: ------------------------------------------------------
: migration/8/62 is trying to acquire lock:
: (&port_lock_key){-.-.}, at: serial8250_console_write()
:
: but task is already holding lock:
: (&rq->lock){-.-.}, at: sched_cpu_dying()
:
: which lock already depends on the new lock.
:
:
: the existing dependency chain (in reverse order) is:
:
: -> #3 (&rq->lock){-.-.}:
: __lock_acquire()
: lock_acquire()
: _raw_spin_lock()
: task_fork_fair()
: sched_fork()
: copy_process.part.31()
: _do_fork()
: kernel_thread()
: rest_init()
: start_kernel()
: x86_64_start_reservations()
: x86_64_start_kernel()
: verify_cpu()
:
: -> #2 (&p->pi_lock){-.-.}:
: __lock_acquire()
: lock_acquire()
: _raw_spin_lock_irqsave()
: try_to_wake_up()
: default_wake_function()
: woken_wake_function()
: __wake_up_common()
: __wake_up_common_lock()
: __wake_up()
: tty_wakeup()
: tty_port_default_wakeup()
: tty_port_tty_wakeup()
: uart_write_wakeup()
: serial8250_tx_chars()
: serial8250_handle_irq.part.25()
: serial8250_default_handle_irq()
: serial8250_interrupt()
: __handle_irq_event_percpu()
: handle_irq_event_percpu()
: handle_irq_event()
: handle_level_irq()
: handle_irq()
: do_IRQ()
: ret_from_intr()
: native_safe_halt()
: default_idle()
: arch_cpu_idle()
: default_idle_call()
: do_idle()
: cpu_startup_entry()
: rest_init()
: start_kernel()
: x86_64_start_reservations()
: x86_64_start_kernel()
: verify_cpu()
:
: -> #1 (&tty->write_wait){-.-.}:
: __lock_acquire()
: lock_acquire()
: _raw_spin_lock_irqsave()
: __wake_up_common_lock()
: __wake_up()
: tty_wakeup()
: tty_port_default_wakeup()
: tty_port_tty_wakeup()
: uart_write_wakeup()
: serial8250_tx_chars()
: serial8250_handle_irq.part.25()
: serial8250_default_handle_irq()
: serial8250_interrupt()
: __handle_irq_event_percpu()
: handle_irq_event_percpu()
: handle_irq_event()
: handle_level_irq()
: handle_irq()
: do_IRQ()
: ret_from_intr()
: native_safe_halt()
: default_idle()
: arch_cpu_idle()
: default_idle_call()
: do_idle()
: cpu_startup_entry()
: rest_init()
: start_kernel()
: x86_64_start_reservations()
: x86_64_start_kernel()
: verify_cpu()
:
: -> #0 (&port_lock_key){-.-.}:
: check_prev_add()
: __lock_acquire()
: lock_acquire()
: _raw_spin_lock_irqsave()
: serial8250_console_write()
: univ8250_console_write()
: console_unlock()
: vprintk_emit()
: vprintk_default()
: vprintk_func()
: printk()
: ___ratelimit()
: __printk_ratelimit()
: select_fallback_rq()
: sched_cpu_dying()
: cpuhp_invoke_callback()
: take_cpu_down()
: multi_cpu_stop()
: cpu_stopper_thread()
: smpboot_thread_fn()
: kthread()
: ret_from_fork()
:
: other info that might help us debug this:
:
: Chain exists of:
: &port_lock_key --> &p->pi_lock --> &rq->lock
:
: Possible unsafe locking scenario:
:
: CPU0 CPU1
: ---- ----
: lock(&rq->lock);
: lock(&p->pi_lock);
: lock(&rq->lock);
: lock(&port_lock_key);
:
: *** DEADLOCK ***
:
: 4 locks held by migration/8/62:
: #0: (&p->pi_lock){-.-.}, at: sched_cpu_dying()
: #1: (&rq->lock){-.-.}, at: sched_cpu_dying()
: #2: (printk_ratelimit_state.lock){....}, at: ___ratelimit()
: #3: (console_lock){+.+.}, at: vprintk_emit()
:
: stack backtrace:
: CPU: 8 PID: 62 Comm: migration/8 Not tainted 4.14.0-rc2-next-20170927+ #252
: Call Trace:
: dump_stack()
: print_circular_bug()
: check_prev_add()
: ? add_lock_to_list.isra.26()
: ? check_usage()
: ? kvm_clock_read()
: ? kvm_sched_clock_read()
: ? sched_clock()
: ? check_preemption_disabled()
: __lock_acquire()
: ? __lock_acquire()
: ? add_lock_to_list.isra.26()
: ? debug_check_no_locks_freed()
: ? memcpy()
: lock_acquire()
: ? serial8250_console_write()
: _raw_spin_lock_irqsave()
: ? serial8250_console_write()
: serial8250_console_write()
: ? serial8250_start_tx()
: ? lock_acquire()
: ? memcpy()
: univ8250_console_write()
: console_unlock()
: ? __down_trylock_console_sem()
: vprintk_emit()
: vprintk_default()
: vprintk_func()
: printk()
: ? show_regs_print_info()
: ? lock_acquire()
: ___ratelimit()
: __printk_ratelimit()
: select_fallback_rq()
: sched_cpu_dying()
: ? sched_cpu_starting()
: ? rcutree_dying_cpu()
: ? sched_cpu_starting()
: cpuhp_invoke_callback()
: ? cpu_disable_common()
: take_cpu_down()
: ? trace_hardirqs_off_caller()
: ? cpuhp_invoke_callback()
: multi_cpu_stop()
: ? __this_cpu_preempt_check()
: ? cpu_stop_queue_work()
: cpu_stopper_thread()
: ? cpu_stop_create()
: smpboot_thread_fn()
: ? sort_range()
: ? schedule()
: ? __kthread_parkme()
: kthread()
: ? sort_range()
: ? kthread_create_on_node()
: ret_from_fork()
: process 9121 (trinity-c78) no longer affine to cpu8
: smpboot: CPU 8 is now offline
Link: http://lkml.kernel.org/r/20170928120405.18273-1-sergey.senozhatsky@gmail.com
Fixes: 6b1d174 ("ratelimit: extend to print suppressed messages on release")
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reported-by: Sasha Levin <levinsasha928@gmail.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Borislav Petkov <bp@suse.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
zhiwang1
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Oct 9, 2017
The dead circular lock senario captured is as followed. The idea of the fix is moving read_user_wptr outside of acquire_queue...release_queue critical section [ 63.477482] WARNING: possible circular locking dependency detected [ 63.484091] 4.12.0-kfd-ozeng #3 Not tainted [ 63.488531] ------------------------------------------------------ [ 63.495146] HelloWorldLoop/2526 is trying to acquire lock: [ 63.501011] (&mm->mmap_sem){++++++}, at: [<ffffffff911898ce>] __might_fault+0x3e/0x90 [ 63.509472] but task is already holding lock: [ 63.515716] (&adev->srbm_mutex){+.+...}, at: [<ffffffffc0484feb>] lock_srbm+0x2b/0x50 [amdgpu] [ 63.525099] which lock already depends on the new lock. [ 63.533841] the existing dependency chain (in reverse order) is: [ 63.541839] -> #2 (&adev->srbm_mutex){+.+...}: [ 63.548178] lock_acquire+0x6d/0x90 [ 63.552461] __mutex_lock+0x70/0x8c0 [ 63.556826] mutex_lock_nested+0x16/0x20 [ 63.561603] gfx_v8_0_kiq_resume+0x1039/0x14a0 [amdgpu] [ 63.567817] gfx_v8_0_hw_init+0x204d/0x2210 [amdgpu] [ 63.573675] amdgpu_device_init+0xdea/0x1790 [amdgpu] [ 63.579640] amdgpu_driver_load_kms+0x63/0x220 [amdgpu] [ 63.585743] drm_dev_register+0x145/0x1e0 [ 63.590605] amdgpu_pci_probe+0x11e/0x160 [amdgpu] [ 63.596266] local_pci_probe+0x40/0xa0 [ 63.600803] pci_device_probe+0x134/0x150 [ 63.605650] driver_probe_device+0x2a1/0x460 [ 63.610785] __driver_attach+0xdc/0xe0 [ 63.615321] bus_for_each_dev+0x5f/0x90 [ 63.619984] driver_attach+0x19/0x20 [ 63.624337] bus_add_driver+0x40/0x270 [ 63.628908] driver_register+0x5b/0xe0 [ 63.633446] __pci_register_driver+0x5b/0x60 [ 63.638586] rtsx_pci_switch_output_voltage+0x1d/0x20 [rtsx_pci] [ 63.645564] do_one_initcall+0x4c/0x1b0 [ 63.650205] do_init_module+0x56/0x1ea [ 63.654767] load_module+0x208c/0x27d0 [ 63.659335] SYSC_finit_module+0x96/0xd0 [ 63.664058] SyS_finit_module+0x9/0x10 [ 63.668629] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 63.674088] -> #1 (reservation_ww_class_mutex){+.+.+.}: [ 63.681257] lock_acquire+0x6d/0x90 [ 63.685551] __ww_mutex_lock.constprop.11+0x8c/0xed0 [ 63.691426] ww_mutex_lock+0x67/0x70 [ 63.695802] amdgpu_verify_access+0x6d/0x100 [amdgpu] [ 63.701743] ttm_bo_mmap+0x8e/0x100 [ttm] [ 63.706615] amdgpu_bo_mmap+0xd/0x60 [amdgpu] [ 63.711814] amdgpu_mmap+0x35/0x40 [amdgpu] [ 63.716904] mmap_region+0x3b5/0x5a0 [ 63.721255] do_mmap+0x400/0x4d0 [ 63.725260] vm_mmap_pgoff+0xb0/0xf0 [ 63.729625] SyS_mmap_pgoff+0x19e/0x260 [ 63.734292] SyS_mmap+0x1d/0x20 [ 63.738199] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 63.743681] -> #0 (&mm->mmap_sem){++++++}: [ 63.749641] __lock_acquire+0x1401/0x1420 [ 63.754491] lock_acquire+0x6d/0x90 [ 63.758750] __might_fault+0x6b/0x90 [ 63.763176] kgd_hqd_load+0x24f/0x270 [amdgpu] [ 63.768432] load_mqd+0x4b/0x50 [amdkfd] [ 63.773192] create_queue_nocpsch+0x535/0x620 [amdkfd] [ 63.779237] pqm_create_queue+0x34d/0x4f0 [amdkfd] [ 63.784835] kfd_ioctl_create_queue+0x282/0x670 [amdkfd] [ 63.790973] kfd_ioctl+0x310/0x4d0 [amdkfd] [ 63.795944] do_vfs_ioctl+0x90/0x6e0 [ 63.800268] SyS_ioctl+0x74/0x80 [ 63.804207] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 63.809607] other info that might help us debug this: [ 63.818026] Chain exists of: &mm->mmap_sem --> reservation_ww_class_mutex --> &adev->srbm_mutex [ 63.830382] Possible unsafe locking scenario: [ 63.836605] CPU0 CPU1 [ 63.841364] ---- ---- [ 63.846123] lock(&adev->srbm_mutex); [ 63.850061] lock(reservation_ww_class_mutex); [ 63.857475] lock(&adev->srbm_mutex); [ 63.864084] lock(&mm->mmap_sem); [ 63.867657] *** DEADLOCK *** [ 63.873884] 3 locks held by HelloWorldLoop/2526: [ 63.878739] #0: (&process->mutex){+.+.+.}, at: [<ffffffffc06e1a9a>] kfd_ioctl_create_queue+0x24a/0x670 [amdkfd] [ 63.889543] #1: (&dqm->lock){+.+...}, at: [<ffffffffc06eedeb>] create_queue_nocpsch+0x3b/0x620 [amdkfd] [ 63.899684] #2: (&adev->srbm_mutex){+.+...}, at: [<ffffffffc0484feb>] lock_srbm+0x2b/0x50 [amdgpu] [ 63.909500] stack backtrace: [ 63.914187] CPU: 3 PID: 2526 Comm: HelloWorldLoop Not tainted 4.12.0-kfd-ozeng #3 [ 63.922184] Hardware name: AMD Carrizo/Gardenia, BIOS WGA5819N_Weekly_15_08_1 08/19/2015 [ 63.930865] Call Trace: [ 63.933464] dump_stack+0x85/0xc9 [ 63.936999] print_circular_bug+0x1f9/0x207 [ 63.941442] __lock_acquire+0x1401/0x1420 [ 63.945745] ? lock_srbm+0x2b/0x50 [amdgpu] [ 63.950185] lock_acquire+0x6d/0x90 [ 63.953885] ? __might_fault+0x3e/0x90 [ 63.957899] __might_fault+0x6b/0x90 [ 63.961699] ? __might_fault+0x3e/0x90 [ 63.965755] kgd_hqd_load+0x24f/0x270 [amdgpu] [ 63.970577] load_mqd+0x4b/0x50 [amdkfd] [ 63.974745] create_queue_nocpsch+0x535/0x620 [amdkfd] [ 63.980242] pqm_create_queue+0x34d/0x4f0 [amdkfd] [ 63.985320] kfd_ioctl_create_queue+0x282/0x670 [amdkfd] [ 63.991021] kfd_ioctl+0x310/0x4d0 [amdkfd] [ 63.995499] ? kfd_ioctl_destroy_queue+0x70/0x70 [amdkfd] [ 64.001234] do_vfs_ioctl+0x90/0x6e0 [ 64.005065] ? up_read+0x1a/0x40 [ 64.008496] SyS_ioctl+0x74/0x80 [ 64.011955] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 64.016863] RIP: 0033:0x7f4b3bd35f07 [ 64.020696] RSP: 002b:00007ffe7689ec38 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 64.028786] RAX: ffffffffffffffda RBX: 00000000002a2000 RCX: 00007f4b3bd35f07 [ 64.036414] RDX: 00007ffe7689ecb0 RSI: 00000000c0584b02 RDI: 0000000000000005 [ 64.044045] RBP: 00007f4a3212d000 R08: 00007f4b3c919000 R09: 0000000000080000 [ 64.051674] R10: 00007f4b376b64b8 R11: 0000000000000246 R12: 00007f4a3212d000 [ 64.059324] R13: 0000000000000015 R14: 0000000000000064 R15: 00007ffe7689ef50 Signed-off-by: Oak Zeng <Oak.Zeng@amd.com> Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
zhiwang1
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Oct 16, 2017
…ug deadlock 4.14-rc1 gained the fancy new cross-release support in lockdep, which seems to have uncovered a few more rules about what is allowed and isn't. This one here seems to indicate that allocating a work-queue while holding mmap_sem is a no-go, so let's try to preallocate it. Of course another way to break this chain would be somewhere in the cpu hotplug code, since this isn't the only trace we're finding now which goes through msr_create_device. Full lockdep splat: ====================================================== WARNING: possible circular locking dependency detected 4.14.0-rc1-CI-CI_DRM_3118+ #1 Tainted: G U ------------------------------------------------------ prime_mmap/1551 is trying to acquire lock: (cpu_hotplug_lock.rw_sem){++++}, at: [<ffffffff8109dbb7>] apply_workqueue_attrs+0x17/0x50 but task is already holding lock: (&dev_priv->mm_lock){+.+.}, at: [<ffffffffa01a7b2a>] i915_gem_userptr_init__mmu_notifier+0x14a/0x270 [i915] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #6 (&dev_priv->mm_lock){+.+.}: __lock_acquire+0x1420/0x15e0 lock_acquire+0xb0/0x200 __mutex_lock+0x86/0x9b0 mutex_lock_nested+0x1b/0x20 i915_gem_userptr_init__mmu_notifier+0x14a/0x270 [i915] i915_gem_userptr_ioctl+0x222/0x2c0 [i915] drm_ioctl_kernel+0x69/0xb0 drm_ioctl+0x2f9/0x3d0 do_vfs_ioctl+0x94/0x670 SyS_ioctl+0x41/0x70 entry_SYSCALL_64_fastpath+0x1c/0xb1 -> #5 (&mm->mmap_sem){++++}: __lock_acquire+0x1420/0x15e0 lock_acquire+0xb0/0x200 __might_fault+0x68/0x90 _copy_to_user+0x23/0x70 filldir+0xa5/0x120 dcache_readdir+0xf9/0x170 iterate_dir+0x69/0x1a0 SyS_getdents+0xa5/0x140 entry_SYSCALL_64_fastpath+0x1c/0xb1 -> #4 (&sb->s_type->i_mutex_key#5){++++}: down_write+0x3b/0x70 handle_create+0xcb/0x1e0 devtmpfsd+0x139/0x180 kthread+0x152/0x190 ret_from_fork+0x27/0x40 -> #3 ((complete)&req.done){+.+.}: __lock_acquire+0x1420/0x15e0 lock_acquire+0xb0/0x200 wait_for_common+0x58/0x210 wait_for_completion+0x1d/0x20 devtmpfs_create_node+0x13d/0x160 device_add+0x5eb/0x620 device_create_groups_vargs+0xe0/0xf0 device_create+0x3a/0x40 msr_device_create+0x2b/0x40 cpuhp_invoke_callback+0xa3/0x840 cpuhp_thread_fun+0x7a/0x150 smpboot_thread_fn+0x18a/0x280 kthread+0x152/0x190 ret_from_fork+0x27/0x40 -> #2 (cpuhp_state){+.+.}: __lock_acquire+0x1420/0x15e0 lock_acquire+0xb0/0x200 cpuhp_issue_call+0x10b/0x170 __cpuhp_setup_state_cpuslocked+0x134/0x2a0 __cpuhp_setup_state+0x46/0x60 page_writeback_init+0x43/0x67 pagecache_init+0x3d/0x42 start_kernel+0x3a8/0x3fc x86_64_start_reservations+0x2a/0x2c x86_64_start_kernel+0x6d/0x70 verify_cpu+0x0/0xfb -> #1 (cpuhp_state_mutex){+.+.}: __lock_acquire+0x1420/0x15e0 lock_acquire+0xb0/0x200 __mutex_lock+0x86/0x9b0 mutex_lock_nested+0x1b/0x20 __cpuhp_setup_state_cpuslocked+0x52/0x2a0 __cpuhp_setup_state+0x46/0x60 page_alloc_init+0x28/0x30 start_kernel+0x145/0x3fc x86_64_start_reservations+0x2a/0x2c x86_64_start_kernel+0x6d/0x70 verify_cpu+0x0/0xfb -> #0 (cpu_hotplug_lock.rw_sem){++++}: check_prev_add+0x430/0x840 __lock_acquire+0x1420/0x15e0 lock_acquire+0xb0/0x200 cpus_read_lock+0x3d/0xb0 apply_workqueue_attrs+0x17/0x50 __alloc_workqueue_key+0x1d8/0x4d9 i915_gem_userptr_init__mmu_notifier+0x1fb/0x270 [i915] i915_gem_userptr_ioctl+0x222/0x2c0 [i915] drm_ioctl_kernel+0x69/0xb0 drm_ioctl+0x2f9/0x3d0 do_vfs_ioctl+0x94/0x670 SyS_ioctl+0x41/0x70 entry_SYSCALL_64_fastpath+0x1c/0xb1 other info that might help us debug this: Chain exists of: cpu_hotplug_lock.rw_sem --> &mm->mmap_sem --> &dev_priv->mm_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&dev_priv->mm_lock); lock(&mm->mmap_sem); lock(&dev_priv->mm_lock); lock(cpu_hotplug_lock.rw_sem); *** DEADLOCK *** 2 locks held by prime_mmap/1551: #0: (&mm->mmap_sem){++++}, at: [<ffffffffa01a7b18>] i915_gem_userptr_init__mmu_notifier+0x138/0x270 [i915] #1: (&dev_priv->mm_lock){+.+.}, at: [<ffffffffa01a7b2a>] i915_gem_userptr_init__mmu_notifier+0x14a/0x270 [i915] stack backtrace: CPU: 4 PID: 1551 Comm: prime_mmap Tainted: G U 4.14.0-rc1-CI-CI_DRM_3118+ #1 Hardware name: Dell Inc. XPS 8300 /0Y2MRG, BIOS A06 10/17/2011 Call Trace: dump_stack+0x68/0x9f print_circular_bug+0x235/0x3c0 ? lockdep_init_map_crosslock+0x20/0x20 check_prev_add+0x430/0x840 __lock_acquire+0x1420/0x15e0 ? __lock_acquire+0x1420/0x15e0 ? lockdep_init_map_crosslock+0x20/0x20 lock_acquire+0xb0/0x200 ? apply_workqueue_attrs+0x17/0x50 cpus_read_lock+0x3d/0xb0 ? apply_workqueue_attrs+0x17/0x50 apply_workqueue_attrs+0x17/0x50 __alloc_workqueue_key+0x1d8/0x4d9 ? __lockdep_init_map+0x57/0x1c0 i915_gem_userptr_init__mmu_notifier+0x1fb/0x270 [i915] i915_gem_userptr_ioctl+0x222/0x2c0 [i915] ? i915_gem_userptr_release+0x140/0x140 [i915] drm_ioctl_kernel+0x69/0xb0 drm_ioctl+0x2f9/0x3d0 ? i915_gem_userptr_release+0x140/0x140 [i915] ? __do_page_fault+0x2a4/0x570 do_vfs_ioctl+0x94/0x670 ? entry_SYSCALL_64_fastpath+0x5/0xb1 ? __this_cpu_preempt_check+0x13/0x20 ? trace_hardirqs_on_caller+0xe3/0x1b0 SyS_ioctl+0x41/0x70 entry_SYSCALL_64_fastpath+0x1c/0xb1 RIP: 0033:0x7fbb83c39587 RSP: 002b:00007fff188dc228 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: ffffffff81492963 RCX: 00007fbb83c39587 RDX: 00007fff188dc260 RSI: 00000000c0186473 RDI: 0000000000000003 RBP: ffffc90001487f88 R08: 0000000000000000 R09: 00007fff188dc2ac R10: 00007fbb83efcb58 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000003 R14: 00000000c0186473 R15: 00007fff188dc2ac ? __this_cpu_preempt_check+0x13/0x20 Note that this also has the minor benefit of slightly reducing the critical section where we hold mmap_sem. v2: Set ret correctly when we raced with another thread. v3: Use Chris' diff. Attach the right lockdep splat. v4: Repaint in Tvrtko's colors (aka don't report ENOMEM if we race and some other thread managed to not also get an ENOMEM and successfully install the mmu notifier. Note that the kernel guarantees that small allocations succeed, so this never actually happens). Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Sasha Levin <alexander.levin@verizon.com> Cc: Marta Lofstedt <marta.lofstedt@intel.com> Cc: Tejun Heo <tj@kernel.org> References: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_3180/shard-hsw3/igt@prime_mmap@test_userptr.html Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=102939 Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20171009164401.16035-1-daniel.vetter@ffwll.ch
zhiwang1
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Oct 16, 2017
stop_machine is not really a locking primitive we should use, except when the hw folks tell us the hw is broken and that's the only way to work around it. This patch tries to address the locking abuse of stop_machine() from commit 20e4933 Author: Chris Wilson <chris@chris-wilson.co.uk> Date: Tue Nov 22 14:41:21 2016 +0000 drm/i915: Stop the machine as we install the wedged submit_request handler Chris said parts of the reasons for going with stop_machine() was that it's no overhead for the fast-path. But these callbacks use irqsave spinlocks and do a bunch of MMIO, and rcu_read_lock is _real_ fast. To stay as close as possible to the stop_machine semantics we first update all the submit function pointers to the nop handler, then call synchronize_rcu() to make sure no new requests can be submitted. This should give us exactly the huge barrier we want. I pondered whether we should annotate engine->submit_request as __rcu and use rcu_assign_pointer and rcu_dereference on it. But the reason behind those is to make sure the compiler/cpu barriers are there for when you have an actual data structure you point at, to make sure all the writes are seen correctly on the read side. But we just have a function pointer, and .text isn't changed, so no need for these barriers and hence no need for annotations. Unfortunately there's a complication with the call to intel_engine_init_global_seqno: - Without stop_machine we must hold the corresponding spinlock. - Without stop_machine we must ensure that all requests are marked as having failed with dma_fence_set_error() before we call it. That means we need to split the nop request submission into two phases, both synchronized with rcu: 1. Only stop submitting the requests to hw and mark them as failed. 2. After all pending requests in the scheduler/ring are suitably marked up as failed and we can force complete them all, also force complete by calling intel_engine_init_global_seqno(). This should fix the followwing lockdep splat: ====================================================== WARNING: possible circular locking dependency detected 4.14.0-rc3-CI-CI_DRM_3179+ #1 Tainted: G U ------------------------------------------------------ kworker/3:4/562 is trying to acquire lock: (cpu_hotplug_lock.rw_sem){++++}, at: [<ffffffff8113d4bc>] stop_machine+0x1c/0x40 but task is already holding lock: (&dev->struct_mutex){+.+.}, at: [<ffffffffa0136588>] i915_reset_device+0x1e8/0x260 [i915] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #6 (&dev->struct_mutex){+.+.}: __lock_acquire+0x1420/0x15e0 lock_acquire+0xb0/0x200 __mutex_lock+0x86/0x9b0 mutex_lock_interruptible_nested+0x1b/0x20 i915_mutex_lock_interruptible+0x51/0x130 [i915] i915_gem_fault+0x209/0x650 [i915] __do_fault+0x1e/0x80 __handle_mm_fault+0xa08/0xed0 handle_mm_fault+0x156/0x300 __do_page_fault+0x2c5/0x570 do_page_fault+0x28/0x250 page_fault+0x22/0x30 -> #5 (&mm->mmap_sem){++++}: __lock_acquire+0x1420/0x15e0 lock_acquire+0xb0/0x200 __might_fault+0x68/0x90 _copy_to_user+0x23/0x70 filldir+0xa5/0x120 dcache_readdir+0xf9/0x170 iterate_dir+0x69/0x1a0 SyS_getdents+0xa5/0x140 entry_SYSCALL_64_fastpath+0x1c/0xb1 -> #4 (&sb->s_type->i_mutex_key#5){++++}: down_write+0x3b/0x70 handle_create+0xcb/0x1e0 devtmpfsd+0x139/0x180 kthread+0x152/0x190 ret_from_fork+0x27/0x40 -> #3 ((complete)&req.done){+.+.}: __lock_acquire+0x1420/0x15e0 lock_acquire+0xb0/0x200 wait_for_common+0x58/0x210 wait_for_completion+0x1d/0x20 devtmpfs_create_node+0x13d/0x160 device_add+0x5eb/0x620 device_create_groups_vargs+0xe0/0xf0 device_create+0x3a/0x40 msr_device_create+0x2b/0x40 cpuhp_invoke_callback+0xc9/0xbf0 cpuhp_thread_fun+0x17b/0x240 smpboot_thread_fn+0x18a/0x280 kthread+0x152/0x190 ret_from_fork+0x27/0x40 -> #2 (cpuhp_state-up){+.+.}: __lock_acquire+0x1420/0x15e0 lock_acquire+0xb0/0x200 cpuhp_issue_call+0x133/0x1c0 __cpuhp_setup_state_cpuslocked+0x139/0x2a0 __cpuhp_setup_state+0x46/0x60 page_writeback_init+0x43/0x67 pagecache_init+0x3d/0x42 start_kernel+0x3a8/0x3fc x86_64_start_reservations+0x2a/0x2c x86_64_start_kernel+0x6d/0x70 verify_cpu+0x0/0xfb -> #1 (cpuhp_state_mutex){+.+.}: __lock_acquire+0x1420/0x15e0 lock_acquire+0xb0/0x200 __mutex_lock+0x86/0x9b0 mutex_lock_nested+0x1b/0x20 __cpuhp_setup_state_cpuslocked+0x53/0x2a0 __cpuhp_setup_state+0x46/0x60 page_alloc_init+0x28/0x30 start_kernel+0x145/0x3fc x86_64_start_reservations+0x2a/0x2c x86_64_start_kernel+0x6d/0x70 verify_cpu+0x0/0xfb -> #0 (cpu_hotplug_lock.rw_sem){++++}: check_prev_add+0x430/0x840 __lock_acquire+0x1420/0x15e0 lock_acquire+0xb0/0x200 cpus_read_lock+0x3d/0xb0 stop_machine+0x1c/0x40 i915_gem_set_wedged+0x1a/0x20 [i915] i915_reset+0xb9/0x230 [i915] i915_reset_device+0x1f6/0x260 [i915] i915_handle_error+0x2d8/0x430 [i915] hangcheck_declare_hang+0xd3/0xf0 [i915] i915_hangcheck_elapsed+0x262/0x2d0 [i915] process_one_work+0x233/0x660 worker_thread+0x4e/0x3b0 kthread+0x152/0x190 ret_from_fork+0x27/0x40 other info that might help us debug this: Chain exists of: cpu_hotplug_lock.rw_sem --> &mm->mmap_sem --> &dev->struct_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&dev->struct_mutex); lock(&mm->mmap_sem); lock(&dev->struct_mutex); lock(cpu_hotplug_lock.rw_sem); *** DEADLOCK *** 3 locks held by kworker/3:4/562: #0: ("events_long"){+.+.}, at: [<ffffffff8109c64a>] process_one_work+0x1aa/0x660 #1: ((&(&i915->gpu_error.hangcheck_work)->work)){+.+.}, at: [<ffffffff8109c64a>] process_one_work+0x1aa/0x660 #2: (&dev->struct_mutex){+.+.}, at: [<ffffffffa0136588>] i915_reset_device+0x1e8/0x260 [i915] stack backtrace: CPU: 3 PID: 562 Comm: kworker/3:4 Tainted: G U 4.14.0-rc3-CI-CI_DRM_3179+ #1 Hardware name: /NUC7i5BNB, BIOS BNKBL357.86A.0048.2017.0704.1415 07/04/2017 Workqueue: events_long i915_hangcheck_elapsed [i915] Call Trace: dump_stack+0x68/0x9f print_circular_bug+0x235/0x3c0 ? lockdep_init_map_crosslock+0x20/0x20 check_prev_add+0x430/0x840 ? irq_work_queue+0x86/0xe0 ? wake_up_klogd+0x53/0x70 __lock_acquire+0x1420/0x15e0 ? __lock_acquire+0x1420/0x15e0 ? lockdep_init_map_crosslock+0x20/0x20 lock_acquire+0xb0/0x200 ? stop_machine+0x1c/0x40 ? i915_gem_object_truncate+0x50/0x50 [i915] cpus_read_lock+0x3d/0xb0 ? stop_machine+0x1c/0x40 stop_machine+0x1c/0x40 i915_gem_set_wedged+0x1a/0x20 [i915] i915_reset+0xb9/0x230 [i915] i915_reset_device+0x1f6/0x260 [i915] ? gen8_gt_irq_ack+0x170/0x170 [i915] ? work_on_cpu_safe+0x60/0x60 i915_handle_error+0x2d8/0x430 [i915] ? vsnprintf+0xd1/0x4b0 ? scnprintf+0x3a/0x70 hangcheck_declare_hang+0xd3/0xf0 [i915] ? intel_runtime_pm_put+0x56/0xa0 [i915] i915_hangcheck_elapsed+0x262/0x2d0 [i915] process_one_work+0x233/0x660 worker_thread+0x4e/0x3b0 kthread+0x152/0x190 ? process_one_work+0x660/0x660 ? kthread_create_on_node+0x40/0x40 ret_from_fork+0x27/0x40 Setting dangerous option reset - tainting kernel i915 0000:00:02.0: Resetting chip after gpu hang Setting dangerous option reset - tainting kernel i915 0000:00:02.0: Resetting chip after gpu hang v2: Have 1 global synchronize_rcu() barrier across all engines, and improve commit message. v3: We need to protect the seqno update with the timeline spinlock (in set_wedged) to avoid racing with other updates of the seqno, like we already do in nop_submit_request (Chris). v4: Use two-phase sequence to plug the race Chris spotted where we can complete requests before they're marked up with -EIO. v5: Review from Chris: - simplify nop_submit_request. - Add comment to rcu_read_lock section. - Align comments with the new style. v6: Remove unused variable to appease CI. Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=102886 Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=103096 Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Mika Kuoppala <mika.kuoppala@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Marta Lofstedt <marta.lofstedt@intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20171011091019.1425-1-daniel.vetter@ffwll.ch
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Purely to silence lockdep, as we know that no bo can exist at this time and so the inversion is impossible. Nevertheless, lockdep currently warns on unload: [ 137.522565] WARNING: possible circular locking dependency detected [ 137.522568] 4.14.0-rc4-CI-CI_DRM_3209+ #1 Tainted: G U [ 137.522570] ------------------------------------------------------ [ 137.522572] drv_module_relo/1532 is trying to acquire lock: [ 137.522574] ("i915-userptr-acquire"){+.+.}, at: [<ffffffff8109a831>] flush_workqueue+0x91/0x540 [ 137.522581] but task is already holding lock: [ 137.522583] (&dev->struct_mutex){+.+.}, at: [<ffffffffa014fb3f>] i915_gem_fini+0x3f/0xc0 [i915] [ 137.522605] which lock already depends on the new lock. [ 137.522608] the existing dependency chain (in reverse order) is: [ 137.522611] -> #3 (&dev->struct_mutex){+.+.}: [ 137.522615] __lock_acquire+0x1420/0x15e0 [ 137.522618] lock_acquire+0xb0/0x200 [ 137.522621] __mutex_lock+0x86/0x9b0 [ 137.522623] mutex_lock_interruptible_nested+0x1b/0x20 [ 137.522640] i915_mutex_lock_interruptible+0x51/0x130 [i915] [ 137.522657] i915_gem_fault+0x20b/0x720 [i915] [ 137.522660] __do_fault+0x1e/0x80 [ 137.522662] __handle_mm_fault+0xa08/0xed0 [ 137.522664] handle_mm_fault+0x156/0x300 [ 137.522666] __do_page_fault+0x2c5/0x570 [ 137.522668] do_page_fault+0x28/0x250 [ 137.522671] page_fault+0x22/0x30 [ 137.522672] -> #2 (&mm->mmap_sem){++++}: [ 137.522677] __lock_acquire+0x1420/0x15e0 [ 137.522679] lock_acquire+0xb0/0x200 [ 137.522682] down_read+0x3e/0x70 [ 137.522699] __i915_gem_userptr_get_pages_worker+0x141/0x240 [i915] [ 137.522701] process_one_work+0x233/0x660 [ 137.522704] worker_thread+0x4e/0x3b0 [ 137.522706] kthread+0x152/0x190 [ 137.522708] ret_from_fork+0x27/0x40 [ 137.522710] -> #1 ((&work->work)){+.+.}: [ 137.522714] __lock_acquire+0x1420/0x15e0 [ 137.522717] lock_acquire+0xb0/0x200 [ 137.522719] process_one_work+0x206/0x660 [ 137.522721] worker_thread+0x4e/0x3b0 [ 137.522723] kthread+0x152/0x190 [ 137.522725] ret_from_fork+0x27/0x40 [ 137.522727] -> #0 ("i915-userptr-acquire"){+.+.}: [ 137.522731] check_prev_add+0x430/0x840 [ 137.522733] __lock_acquire+0x1420/0x15e0 [ 137.522735] lock_acquire+0xb0/0x200 [ 137.522738] flush_workqueue+0xb4/0x540 [ 137.522740] drain_workqueue+0xd4/0x1b0 [ 137.522742] destroy_workqueue+0x1c/0x200 [ 137.522758] i915_gem_cleanup_userptr+0x15/0x20 [i915] [ 137.522770] i915_gem_fini+0x5f/0xc0 [i915] [ 137.522782] i915_driver_unload+0x122/0x180 [i915] [ 137.522794] i915_pci_remove+0x19/0x30 [i915] [ 137.522797] pci_device_remove+0x39/0xb0 [ 137.522800] device_release_driver_internal+0x15d/0x220 [ 137.522803] driver_detach+0x40/0x80 [ 137.522805] bus_remove_driver+0x58/0xd0 [ 137.522807] driver_unregister+0x2c/0x40 [ 137.522809] pci_unregister_driver+0x36/0xb0 [ 137.522828] i915_exit+0x1a/0x8b [i915] [ 137.522831] SyS_delete_module+0x18c/0x1e0 [ 137.522834] entry_SYSCALL_64_fastpath+0x1c/0xb1 [ 137.522835] other info that might help us debug this: [ 137.522838] Chain exists of: "i915-userptr-acquire" --> &mm->mmap_sem --> &dev->struct_mutex [ 137.522844] Possible unsafe locking scenario: [ 137.522846] CPU0 CPU1 [ 137.522848] ---- ---- [ 137.522850] lock(&dev->struct_mutex); [ 137.522852] lock(&mm->mmap_sem); [ 137.522854] lock(&dev->struct_mutex); [ 137.522857] lock("i915-userptr-acquire"); [ 137.522859] *** DEADLOCK *** [ 137.522862] 3 locks held by drv_module_relo/1532: [ 137.522864] #0: (&dev->mutex){....}, at: [<ffffffff8161d47b>] device_release_driver_internal+0x2b/0x220 [ 137.522869] #1: (&dev->mutex){....}, at: [<ffffffff8161d489>] device_release_driver_internal+0x39/0x220 [ 137.522873] #2: (&dev->struct_mutex){+.+.}, at: [<ffffffffa014fb3f>] i915_gem_fini+0x3f/0xc0 [i915] [ 137.522888] stack backtrace: [ 137.522891] CPU: 0 PID: 1532 Comm: drv_module_relo Tainted: G U 4.14.0-rc4-CI-CI_DRM_3209+ #1 [ 137.522894] Hardware name: /NUC7i5BNB, BIOS BNKBL357.86A.0048.2017.0704.1415 07/04/2017 [ 137.522897] Call Trace: [ 137.522900] dump_stack+0x68/0x9f [ 137.522902] print_circular_bug+0x235/0x3c0 [ 137.522905] ? lockdep_init_map_crosslock+0x20/0x20 [ 137.522908] check_prev_add+0x430/0x840 [ 137.522919] ? i915_gem_fini+0x5f/0xc0 [i915] [ 137.522922] ? __kernel_text_address+0x12/0x40 [ 137.522925] ? __save_stack_trace+0x66/0xd0 [ 137.522928] __lock_acquire+0x1420/0x15e0 [ 137.522930] ? __lock_acquire+0x1420/0x15e0 [ 137.522933] ? lockdep_init_map_crosslock+0x20/0x20 [ 137.522936] ? __this_cpu_preempt_check+0x13/0x20 [ 137.522938] lock_acquire+0xb0/0x200 [ 137.522940] ? flush_workqueue+0x91/0x540 [ 137.522943] flush_workqueue+0xb4/0x540 [ 137.522945] ? flush_workqueue+0x91/0x540 [ 137.522948] ? __mutex_unlock_slowpath+0x43/0x2c0 [ 137.522951] ? trace_hardirqs_on_caller+0xe3/0x1b0 [ 137.522954] drain_workqueue+0xd4/0x1b0 [ 137.522956] ? drain_workqueue+0xd4/0x1b0 [ 137.522958] destroy_workqueue+0x1c/0x200 [ 137.522975] i915_gem_cleanup_userptr+0x15/0x20 [i915] [ 137.522987] i915_gem_fini+0x5f/0xc0 [i915] [ 137.523000] i915_driver_unload+0x122/0x180 [i915] [ 137.523015] i915_pci_remove+0x19/0x30 [i915] [ 137.523018] pci_device_remove+0x39/0xb0 [ 137.523021] device_release_driver_internal+0x15d/0x220 [ 137.523023] driver_detach+0x40/0x80 [ 137.523026] bus_remove_driver+0x58/0xd0 [ 137.523028] driver_unregister+0x2c/0x40 [ 137.523030] pci_unregister_driver+0x36/0xb0 [ 137.523049] i915_exit+0x1a/0x8b [i915] [ 137.523052] SyS_delete_module+0x18c/0x1e0 [ 137.523055] entry_SYSCALL_64_fastpath+0x1c/0xb1 [ 137.523057] RIP: 0033:0x7f7bd0609287 [ 137.523059] RSP: 002b:00007ffef694bc18 EFLAGS: 00000246 ORIG_RAX: 00000000000000b0 [ 137.523062] RAX: ffffffffffffffda RBX: ffffffff81493f33 RCX: 00007f7bd0609287 [ 137.523065] RDX: 0000000000000001 RSI: 0000000000000800 RDI: 0000564f999f9fc8 [ 137.523067] RBP: ffffc90005c4ff88 R08: 0000000000000000 R09: 0000000000000080 [ 137.523069] R10: 00007f7bd20ef8c0 R11: 0000000000000246 R12: 0000000000000000 [ 137.523072] R13: 00007ffef694be00 R14: 0000000000000000 R15: 0000000000000000 [ 137.523075] ? __this_cpu_preempt_check+0x13/0x20 Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/20171011141857.14161-1-chris@chris-wilson.co.uk Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
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Time to remove less important info and make messages clear and consistent. v2: change some message levels (Chris) v3: restore DRM_WARN (Chris) Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com> Cc: Sagar Arun Kamble <sagar.a.kamble@intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> #2 Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20171016144724.17244-10-michal.wajdeczko@intel.com
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Thomas reported that 'perf buildid-list' gets a SEGFAULT due to NULL pointer deref when he ran it on a data with namespace events. It was because the buildid_id__mark_dso_hit_ops lacks the namespace event handler and perf_too__fill_default() didn't set it. Program received signal SIGSEGV, Segmentation fault. 0x0000000000000000 in ?? () Missing separate debuginfos, use: dnf debuginfo-install audit-libs-2.7.7-1.fc25.s390x bzip2-libs-1.0.6-21.fc25.s390x elfutils-libelf-0.169-1.fc25.s390x +elfutils-libs-0.169-1.fc25.s390x libcap-ng-0.7.8-1.fc25.s390x numactl-libs-2.0.11-2.ibm.fc25.s390x openssl-libs-1.1.0e-1.1.ibm.fc25.s390x perl-libs-5.24.1-386.fc25.s390x +python-libs-2.7.13-2.fc25.s390x slang-2.3.0-7.fc25.s390x xz-libs-5.2.3-2.fc25.s390x zlib-1.2.8-10.fc25.s390x (gdb) where #0 0x0000000000000000 in ?? () #1 0x00000000010fad6a in machines__deliver_event (machines=<optimized out>, machines@entry=0x2c6fd18, evlist=<optimized out>, event=event@entry=0x3fffdf00470, sample=0x3ffffffe880, sample@entry=0x3ffffffe888, tool=tool@entry=0x1312968 <build_id.mark_dso_hit_ops>, file_offset=1136) at util/session.c:1287 #2 0x00000000010fbf4e in perf_session__deliver_event (file_offset=1136, tool=0x1312968 <build_id.mark_dso_hit_ops>, sample=0x3ffffffe888, event=0x3fffdf00470, session=0x2c6fc30) at util/session.c:1340 #3 perf_session__process_event (session=0x2c6fc30, session@entry=0x0, event=event@entry=0x3fffdf00470, file_offset=file_offset@entry=1136) at util/session.c:1522 #4 0x00000000010fddde in __perf_session__process_events (file_size=11880, data_size=<optimized out>, data_offset=<optimized out>, session=0x0) at util/session.c:1899 #5 perf_session__process_events (session=0x0, session@entry=0x2c6fc30) at util/session.c:1953 #6 0x000000000103b2ac in perf_session__list_build_ids (with_hits=<optimized out>, force=<optimized out>) at builtin-buildid-list.c:83 #7 cmd_buildid_list (argc=<optimized out>, argv=<optimized out>) at builtin-buildid-list.c:115 #8 0x00000000010a026c in run_builtin (p=0x1311f78 <commands+24>, argc=argc@entry=2, argv=argv@entry=0x3fffffff3c0) at perf.c:296 #9 0x000000000102bc00 in handle_internal_command (argv=<optimized out>, argc=2) at perf.c:348 #10 run_argv (argcp=<synthetic pointer>, argv=<synthetic pointer>) at perf.c:392 #11 main (argc=<optimized out>, argv=0x3fffffff3c0) at perf.c:536 (gdb) Fix it by adding a stub event handler for namespace event. Committer testing: Further clarifying, plain using 'perf buildid-list' will not end up in a SEGFAULT when processing a perf.data file with namespace info: # perf record -a --namespaces sleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 2.024 MB perf.data (1058 samples) ] # perf buildid-list | wc -l 38 # perf buildid-list | head -5 e2a171c7b905826fc8494f0711ba76ab6abbd604 /lib/modules/4.14.0-rc3+/build/vmlinux 874840a02d8f8a31cedd605d0b8653145472ced3 /lib/modules/4.14.0-rc3+/kernel/arch/x86/kvm/kvm-intel.ko ea7223776730cd8a22f320040aae4d54312984bc /lib/modules/4.14.0-rc3+/kernel/drivers/gpu/drm/i915/i915.ko 5961535e6732a8edb7f22b3f148bb2fa2e0be4b9 /lib/modules/4.14.0-rc3+/kernel/drivers/gpu/drm/drm.ko f045f54aa78cf1931cc893f78b6cbc52c72a8cb1 /usr/lib64/libc-2.25.so # It is only when one asks for checking what of those entries actually had samples, i.e. when we use either -H or --with-hits, that we will process all the PERF_RECORD_ events, and since tools/perf/builtin-buildid-list.c neither explicitely set a perf_tool.namespaces() callback nor the default stub was set that we end up, when processing a PERF_RECORD_NAMESPACE record, causing a SEGFAULT: # perf buildid-list -H Segmentation fault (core dumped) ^C # Reported-and-Tested-by: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Hari Bathini <hbathini@linux.vnet.ibm.com> Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com> Fixes: f3b3614 ("perf tools: Add PERF_RECORD_NAMESPACES to include namespaces related info") Link: http://lkml.kernel.org/r/20171017132900.11043-1-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Oct 26, 2017
When an EMAD is transmitted, a timeout work item is scheduled with a delay of 200ms, so that another EMAD will be retried until a maximum of five retries. In certain situations, it's possible for the function waiting on the EMAD to be associated with a work item that is queued on the same workqueue (`mlxsw_core`) as the timeout work item. This results in flushing a work item on the same workqueue. According to commit e159489 ("workqueue: relax lockdep annotation on flush_work()") the above may lead to a deadlock in case the workqueue has only one worker active or if the system in under memory pressure and the rescue worker is in use. The latter explains the very rare and random nature of the lockdep splats we have been seeing: [ 52.730240] ============================================ [ 52.736179] WARNING: possible recursive locking detected [ 52.742119] 4.14.0-rc3jiri+ #4 Not tainted [ 52.746697] -------------------------------------------- [ 52.752635] kworker/1:3/599 is trying to acquire lock: [ 52.758378] (mlxsw_core_driver_name){+.+.}, at: [<ffffffff811c4fa4>] flush_work+0x3a4/0x5e0 [ 52.767837] but task is already holding lock: [ 52.774360] (mlxsw_core_driver_name){+.+.}, at: [<ffffffff811c65c4>] process_one_work+0x7d4/0x12f0 [ 52.784495] other info that might help us debug this: [ 52.791794] Possible unsafe locking scenario: [ 52.798413] CPU0 [ 52.801144] ---- [ 52.803875] lock(mlxsw_core_driver_name); [ 52.808556] lock(mlxsw_core_driver_name); [ 52.813236] *** DEADLOCK *** [ 52.819857] May be due to missing lock nesting notation [ 52.827450] 3 locks held by kworker/1:3/599: [ 52.832221] #0: (mlxsw_core_driver_name){+.+.}, at: [<ffffffff811c65c4>] process_one_work+0x7d4/0x12f0 [ 52.842846] #1: ((&(&bridge->fdb_notify.dw)->work)){+.+.}, at: [<ffffffff811c65c4>] process_one_work+0x7d4/0x12f0 [ 52.854537] #2: (rtnl_mutex){+.+.}, at: [<ffffffff822ad8e7>] rtnl_lock+0x17/0x20 [ 52.863021] stack backtrace: [ 52.867890] CPU: 1 PID: 599 Comm: kworker/1:3 Not tainted 4.14.0-rc3jiri+ #4 [ 52.875773] Hardware name: Mellanox Technologies Ltd. "MSN2100-CB2F"/"SA001017", BIOS 5.6.5 06/07/2016 [ 52.886267] Workqueue: mlxsw_core mlxsw_sp_fdb_notify_work [mlxsw_spectrum] [ 52.894060] Call Trace: [ 52.909122] __lock_acquire+0xf6f/0x2a10 [ 53.025412] lock_acquire+0x158/0x440 [ 53.047557] flush_work+0x3c4/0x5e0 [ 53.087571] __cancel_work_timer+0x3ca/0x5e0 [ 53.177051] cancel_delayed_work_sync+0x13/0x20 [ 53.182142] mlxsw_reg_trans_bulk_wait+0x12d/0x7a0 [mlxsw_core] [ 53.194571] mlxsw_core_reg_access+0x586/0x990 [mlxsw_core] [ 53.225365] mlxsw_reg_query+0x10/0x20 [mlxsw_core] [ 53.230882] mlxsw_sp_fdb_notify_work+0x2a3/0x9d0 [mlxsw_spectrum] [ 53.237801] process_one_work+0x8f1/0x12f0 [ 53.321804] worker_thread+0x1fd/0x10c0 [ 53.435158] kthread+0x28e/0x370 [ 53.448703] ret_from_fork+0x2a/0x40 [ 53.453017] mlxsw_spectrum 0000:01:00.0: EMAD retries (2/5) (tid=bf4549b100000774) [ 53.453119] mlxsw_spectrum 0000:01:00.0: EMAD retries (5/5) (tid=bf4549b100000770) [ 53.453132] mlxsw_spectrum 0000:01:00.0: EMAD reg access failed (tid=bf4549b100000770,reg_id=200b(sfn),type=query,status=0(operation performed)) [ 53.453143] mlxsw_spectrum 0000:01:00.0: Failed to get FDB notifications Fix this by creating another workqueue for EMAD timeouts, thereby preventing the situation of a work item trying to flush a work item queued on the same workqueue. Fixes: caf7297 ("mlxsw: core: Introduce support for asynchronous EMAD register access") Signed-off-by: Ido Schimmel <idosch@mellanox.com> Reported-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
zhenyw
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Nov 2, 2017
v4.10 commit 6f2ce1c ("scsi: zfcp: fix rport unblock race with LUN recovery") extended accessing parent pointer fields of struct zfcp_erp_action for tracing. If an erp_action has never been enqueued before, these parent pointer fields are uninitialized and NULL. Examples are zfcp objects freshly added to the parent object's children list, before enqueueing their first recovery subsequently. In zfcp_erp_try_rport_unblock(), we iterate such list. Accessing erp_action fields can cause a NULL pointer dereference. Since the kernel can read from lowcore on s390, it does not immediately cause a kernel page fault. Instead it can cause hangs on trying to acquire the wrong erp_action->adapter->dbf->rec_lock in zfcp_dbf_rec_action_lvl() ^bogus^ while holding already other locks with IRQs disabled. Real life example from attaching lots of LUNs in parallel on many CPUs: crash> bt 17723 PID: 17723 TASK: ... CPU: 25 COMMAND: "zfcperp0.0.1800" LOWCORE INFO: -psw : 0x0404300180000000 0x000000000038e424 -function : _raw_spin_lock_wait_flags at 38e424 ... #0 [fdde8fc90] zfcp_dbf_rec_action_lvl at 3e0004e9862 [zfcp] #1 [fdde8fce8] zfcp_erp_try_rport_unblock at 3e0004dfddc [zfcp] #2 [fdde8fd38] zfcp_erp_strategy at 3e0004e0234 [zfcp] #3 [fdde8fda8] zfcp_erp_thread at 3e0004e0a12 [zfcp] #4 [fdde8fe60] kthread at 173550 #5 [fdde8feb8] kernel_thread_starter at 10add2 zfcp_adapter zfcp_port zfcp_unit <address>, 0x404040d600000000 scsi_device NULL, returning early! zfcp_scsi_dev.status = 0x40000000 0x40000000 ZFCP_STATUS_COMMON_RUNNING crash> zfcp_unit <address> struct zfcp_unit { erp_action = { adapter = 0x0, port = 0x0, unit = 0x0, }, } zfcp_erp_action is always fully embedded into its container object. Such container object is never moved in its object tree (only add or delete). Hence, erp_action parent pointers can never change. To fix the issue, initialize the erp_action parent pointers before adding the erp_action container to any list and thus before it becomes accessible from outside of its initializing function. In order to also close the time window between zfcp_erp_setup_act() memsetting the entire erp_action to zero and setting the parent pointers again, drop the memset and instead explicitly initialize individually all erp_action fields except for parent pointers. To be extra careful not to introduce any other unintended side effect, even keep zeroing the erp_action fields for list and timer. Also double-check with WARN_ON_ONCE that erp_action parent pointers never change, so we get to know when we would deviate from previous behavior. Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com> Fixes: 6f2ce1c ("scsi: zfcp: fix rport unblock race with LUN recovery") Cc: <stable@vger.kernel.org> #2.6.32+ Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
zhenyw
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Nov 7, 2017
syzkaller with KASAN reported an out-of-bounds read in
asn1_ber_decoder(). It can be reproduced by the following command,
assuming CONFIG_X509_CERTIFICATE_PARSER=y and CONFIG_KASAN=y:
keyctl add asymmetric desc $'\x30\x30' @s
The bug is that the length of an ASN.1 data value isn't validated in the
case where it is encoded using the short form, causing the decoder to
read past the end of the input buffer. Fix it by validating the length.
The bug report was:
BUG: KASAN: slab-out-of-bounds in asn1_ber_decoder+0x10cb/0x1730 lib/asn1_decoder.c:233
Read of size 1 at addr ffff88003cccfa02 by task syz-executor0/6818
CPU: 1 PID: 6818 Comm: syz-executor0 Not tainted 4.14.0-rc7-00008-g5f479447d983 #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:16 [inline]
dump_stack+0xb3/0x10b lib/dump_stack.c:52
print_address_description+0x79/0x2a0 mm/kasan/report.c:252
kasan_report_error mm/kasan/report.c:351 [inline]
kasan_report+0x236/0x340 mm/kasan/report.c:409
__asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:427
asn1_ber_decoder+0x10cb/0x1730 lib/asn1_decoder.c:233
x509_cert_parse+0x1db/0x650 crypto/asymmetric_keys/x509_cert_parser.c:89
x509_key_preparse+0x64/0x7a0 crypto/asymmetric_keys/x509_public_key.c:174
asymmetric_key_preparse+0xcb/0x1a0 crypto/asymmetric_keys/asymmetric_type.c:388
key_create_or_update+0x347/0xb20 security/keys/key.c:855
SYSC_add_key security/keys/keyctl.c:122 [inline]
SyS_add_key+0x1cd/0x340 security/keys/keyctl.c:62
entry_SYSCALL_64_fastpath+0x1f/0xbe
RIP: 0033:0x447c89
RSP: 002b:00007fca7a5d3bd8 EFLAGS: 00000246 ORIG_RAX: 00000000000000f8
RAX: ffffffffffffffda RBX: 00007fca7a5d46cc RCX: 0000000000447c89
RDX: 0000000020006f4a RSI: 0000000020006000 RDI: 0000000020001ff5
RBP: 0000000000000046 R08: fffffffffffffffd R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fca7a5d49c0 R15: 00007fca7a5d4700
Fixes: 42d5ec2 ("X.509: Add an ASN.1 decoder")
Cc: <stable@vger.kernel.org> # v3.7+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
zhenyw
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Nov 14, 2017
On the Samsung Chromebook Plus I get this error with 4.14-rc3: BUG: scheduling while atomic: kworker/3:1/50/0x00000002 Modules linked in: CPU: 3 PID: 50 Comm: kworker/3:1 Not tainted 4.14.0-0.rc3-kevin #2 Hardware name: Google Kevin (DT) Workqueue: events analogix_dp_psr_work Call trace: [<ffffff80080873b0>] dump_backtrace+0x0/0x320 [<ffffff80080876e4>] show_stack+0x14/0x20 [<ffffff8008606d38>] dump_stack+0x9c/0xbc [<ffffff80080c6b5c>] __schedule_bug+0x4c/0x70 [<ffffff80086188c0>] __schedule+0x3f0/0x458 [<ffffff8008618960>] schedule+0x38/0xa0 [<ffffff800861c20c>] schedule_hrtimeout_range_clock+0x84/0xe8 [<ffffff800861c2a0>] schedule_hrtimeout_range+0x10/0x18 [<ffffff800861bcec>] usleep_range+0x64/0x78 [<ffffff8008415a6c>] analogix_dp_transfer+0x16c/0x340 [<ffffff8008412550>] analogix_dpaux_transfer+0x10/0x18 [<ffffff80083ceb14>] drm_dp_dpcd_access+0x4c/0xf0 [<ffffff80083cf614>] drm_dp_dpcd_write+0x1c/0x28 [<ffffff8008413b98>] analogix_dp_disable_psr+0x60/0xa8 [<ffffff800840da3c>] analogix_dp_psr_work+0x4c/0x90 [<ffffff80080bb09c>] process_one_work+0x1d4/0x348 [<ffffff80080bb258>] worker_thread+0x48/0x478 [<ffffff80080c11fc>] kthread+0x12c/0x130 [<ffffff8008084290>] ret_from_fork+0x10/0x18 Changing rockchip_dp_device::psr_lock to a mutex rather than spinlock seems to fix the issue. Signed-off-by: Emil Renner Berthing <kernel@esmil.dk> Tested-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> Signed-off-by: Mark Yao <mark.yao@rock-chips.com> Link: https://patchwork.freedesktop.org/patch/msgid/20171004175346.11956-1-kernel@esmil.dk
zhenyw
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Nov 16, 2017
syzkaller reported a NULL pointer dereference in asn1_ber_decoder(). It
can be reproduced by the following command, assuming
CONFIG_PKCS7_TEST_KEY=y:
keyctl add pkcs7_test desc '' @s
The bug is that if the data buffer is empty, an integer underflow occurs
in the following check:
if (unlikely(dp >= datalen - 1))
goto data_overrun_error;
This results in the NULL data pointer being dereferenced.
Fix it by checking for 'datalen - dp < 2' instead.
Also fix the similar check for 'dp >= datalen - n' later in the same
function. That one possibly could result in a buffer overread.
The NULL pointer dereference was reproducible using the "pkcs7_test" key
type but not the "asymmetric" key type because the "asymmetric" key type
checks for a 0-length payload before calling into the ASN.1 decoder but
the "pkcs7_test" key type does not.
The bug report was:
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: asn1_ber_decoder+0x17f/0xe60 lib/asn1_decoder.c:233
PGD 7b708067 P4D 7b708067 PUD 7b6ee067 PMD 0
Oops: 0000 [#1] SMP
Modules linked in:
CPU: 0 PID: 522 Comm: syz-executor1 Not tainted 4.14.0-rc8 #7
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.3-20171021_125229-anatol 04/01/2014
task: ffff9b6b3798c040 task.stack: ffff9b6b37970000
RIP: 0010:asn1_ber_decoder+0x17f/0xe60 lib/asn1_decoder.c:233
RSP: 0018:ffff9b6b37973c78 EFLAGS: 00010216
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000000000000021c
RDX: ffffffff814a04ed RSI: ffffb1524066e000 RDI: ffffffff910759e0
RBP: ffff9b6b37973d60 R08: 0000000000000001 R09: ffff9b6b3caa4180
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS: 00007f10ed1f2700(0000) GS:ffff9b6b3ea00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000007b6f3000 CR4: 00000000000006f0
Call Trace:
pkcs7_parse_message+0xee/0x240 crypto/asymmetric_keys/pkcs7_parser.c:139
verify_pkcs7_signature+0x33/0x180 certs/system_keyring.c:216
pkcs7_preparse+0x41/0x70 crypto/asymmetric_keys/pkcs7_key_type.c:63
key_create_or_update+0x180/0x530 security/keys/key.c:855
SYSC_add_key security/keys/keyctl.c:122 [inline]
SyS_add_key+0xbf/0x250 security/keys/keyctl.c:62
entry_SYSCALL_64_fastpath+0x1f/0xbe
RIP: 0033:0x4585c9
RSP: 002b:00007f10ed1f1bd8 EFLAGS: 00000216 ORIG_RAX: 00000000000000f8
RAX: ffffffffffffffda RBX: 00007f10ed1f2700 RCX: 00000000004585c9
RDX: 0000000020000000 RSI: 0000000020008ffb RDI: 0000000020008000
RBP: 0000000000000000 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000216 R12: 00007fff1b2260ae
R13: 00007fff1b2260af R14: 00007f10ed1f2700 R15: 0000000000000000
Code: dd ca ff 48 8b 45 88 48 83 e8 01 4c 39 f0 0f 86 a8 07 00 00 e8 53 dd ca ff 49 8d 46 01 48 89 85 58 ff ff ff 48 8b 85 60 ff ff ff <42> 0f b6 0c 30 89 c8 88 8d 75 ff ff ff 83 e0 1f 89 8d 28 ff ff
RIP: asn1_ber_decoder+0x17f/0xe60 lib/asn1_decoder.c:233 RSP: ffff9b6b37973c78
CR2: 0000000000000000
Fixes: 42d5ec2 ("X.509: Add an ASN.1 decoder")
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: <stable@vger.kernel.org> # v3.7+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
zhenyw
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Nov 16, 2017
…kernel/git/jmorris/linux-security Pull key handling fix from James Morris: "Fix by Eric Biggers for the keys subsystem" * 'fixes-v4.14-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: KEYS: fix NULL pointer dereference during ASN.1 parsing [ver #2]
zhenyw
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Nov 24, 2017
We don't need struct_mutex to initialise userptr (it just allocates a workqueue for itself etc), but we do need struct_mutex later on in i915_gem_init() in order to feed requests onto the HW. This should break the chain [ 385.697902] ====================================================== [ 385.697907] WARNING: possible circular locking dependency detected [ 385.697913] 4.14.0-CI-Patchwork_7234+ #1 Tainted: G U [ 385.697917] ------------------------------------------------------ [ 385.697922] perf_pmu/2631 is trying to acquire lock: [ 385.697927] (&mm->mmap_sem){++++}, at: [<ffffffff811bfe1e>] __might_fault+0x3e/0x90 [ 385.697941] but task is already holding lock: [ 385.697946] (&cpuctx_mutex){+.+.}, at: [<ffffffff8116fe8c>] perf_event_ctx_lock_nested+0xbc/0x1d0 [ 385.697957] which lock already depends on the new lock. [ 385.697963] the existing dependency chain (in reverse order) is: [ 385.697970] -> #4 (&cpuctx_mutex){+.+.}: [ 385.697980] __mutex_lock+0x86/0x9b0 [ 385.697985] perf_event_init_cpu+0x5a/0x90 [ 385.697991] perf_event_init+0x178/0x1a4 [ 385.697997] start_kernel+0x27f/0x3f1 [ 385.698003] verify_cpu+0x0/0xfb [ 385.698006] -> #3 (pmus_lock){+.+.}: [ 385.698015] __mutex_lock+0x86/0x9b0 [ 385.698020] perf_event_init_cpu+0x21/0x90 [ 385.698025] cpuhp_invoke_callback+0xca/0xc00 [ 385.698030] _cpu_up+0xa7/0x170 [ 385.698035] do_cpu_up+0x57/0x70 [ 385.698039] smp_init+0x62/0xa6 [ 385.698044] kernel_init_freeable+0x97/0x193 [ 385.698050] kernel_init+0xa/0x100 [ 385.698055] ret_from_fork+0x27/0x40 [ 385.698058] -> #2 (cpu_hotplug_lock.rw_sem){++++}: [ 385.698068] cpus_read_lock+0x39/0xa0 [ 385.698073] apply_workqueue_attrs+0x12/0x50 [ 385.698078] __alloc_workqueue_key+0x1d8/0x4d8 [ 385.698134] i915_gem_init_userptr+0x5f/0x80 [i915] [ 385.698176] i915_gem_init+0x7c/0x390 [i915] [ 385.698213] i915_driver_load+0x99e/0x15c0 [i915] [ 385.698250] i915_pci_probe+0x33/0x90 [i915] [ 385.698256] pci_device_probe+0xa1/0x130 [ 385.698262] driver_probe_device+0x293/0x440 [ 385.698267] __driver_attach+0xde/0xe0 [ 385.698272] bus_for_each_dev+0x5c/0x90 [ 385.698277] bus_add_driver+0x16d/0x260 [ 385.698282] driver_register+0x57/0xc0 [ 385.698287] do_one_initcall+0x3e/0x160 [ 385.698292] do_init_module+0x5b/0x1fa [ 385.698297] load_module+0x2374/0x2dc0 [ 385.698302] SyS_finit_module+0xaa/0xe0 [ 385.698307] entry_SYSCALL_64_fastpath+0x1c/0xb1 [ 385.698311] -> #1 (&dev->struct_mutex){+.+.}: [ 385.698320] __mutex_lock+0x86/0x9b0 [ 385.698361] i915_mutex_lock_interruptible+0x4c/0x130 [i915] [ 385.698403] i915_gem_fault+0x206/0x760 [i915] [ 385.698409] __do_fault+0x1a/0x70 [ 385.698413] __handle_mm_fault+0x7c4/0xdb0 [ 385.698417] handle_mm_fault+0x154/0x300 [ 385.698440] __do_page_fault+0x2d6/0x570 [ 385.698445] page_fault+0x22/0x30 [ 385.698449] -> #0 (&mm->mmap_sem){++++}: [ 385.698459] lock_acquire+0xaf/0x200 [ 385.698464] __might_fault+0x68/0x90 [ 385.698470] _copy_to_user+0x1e/0x70 [ 385.698475] perf_read+0x1aa/0x290 [ 385.698480] __vfs_read+0x23/0x120 [ 385.698484] vfs_read+0xa3/0x150 [ 385.698488] SyS_read+0x45/0xb0 [ 385.698493] entry_SYSCALL_64_fastpath+0x1c/0xb1 [ 385.698497] other info that might help us debug this: [ 385.698505] Chain exists of: &mm->mmap_sem --> pmus_lock --> &cpuctx_mutex [ 385.698517] Possible unsafe locking scenario: [ 385.698522] CPU0 CPU1 [ 385.698526] ---- ---- [ 385.698529] lock(&cpuctx_mutex); [ 385.698553] lock(pmus_lock); [ 385.698558] lock(&cpuctx_mutex); [ 385.698564] lock(&mm->mmap_sem); [ 385.698568] *** DEADLOCK *** [ 385.698574] 1 lock held by perf_pmu/2631: [ 385.698578] #0: (&cpuctx_mutex){+.+.}, at: [<ffffffff8116fe8c>] perf_event_ctx_lock_nested+0xbc/0x1d0 [ 385.698589] stack backtrace: [ 385.698595] CPU: 3 PID: 2631 Comm: perf_pmu Tainted: G U 4.14.0-CI-Patchwork_7234+ #1 [ 385.698602] Hardware name: /NUC6CAYB, BIOS AYAPLCEL.86A.0040.2017.0619.1722 06/19/2017 [ 385.698609] Call Trace: [ 385.698615] dump_stack+0x5f/0x86 [ 385.698621] print_circular_bug.isra.18+0x1d0/0x2c0 [ 385.698627] __lock_acquire+0x19c3/0x1b60 [ 385.698634] ? generic_exec_single+0x77/0xe0 [ 385.698640] ? lock_acquire+0xaf/0x200 [ 385.698644] lock_acquire+0xaf/0x200 [ 385.698650] ? __might_fault+0x3e/0x90 [ 385.698655] __might_fault+0x68/0x90 [ 385.698660] ? __might_fault+0x3e/0x90 [ 385.698665] _copy_to_user+0x1e/0x70 [ 385.698670] perf_read+0x1aa/0x290 [ 385.698675] __vfs_read+0x23/0x120 [ 385.698682] ? __fget+0x101/0x1f0 [ 385.698686] vfs_read+0xa3/0x150 [ 385.698691] SyS_read+0x45/0xb0 [ 385.698696] entry_SYSCALL_64_fastpath+0x1c/0xb1 [ 385.698701] RIP: 0033:0x7ff1c46876ed [ 385.698705] RSP: 002b:00007fff13552f90 EFLAGS: 00000293 ORIG_RAX: 0000000000000000 [ 385.698712] RAX: ffffffffffffffda RBX: ffffc90000647ff0 RCX: 00007ff1c46876ed [ 385.698718] RDX: 0000000000000010 RSI: 00007fff13552fa0 RDI: 0000000000000005 [ 385.698723] RBP: 000056063d300580 R08: 0000000000000000 R09: 0000000000000060 [ 385.698729] R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000046 [ 385.698734] R13: 00007fff13552c6f R14: 00007ff1c6279d00 R15: 00007ff1c6279a40 Testcase: igt/perf_pmu Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20171122172621.16158-1-chris@chris-wilson.co.uk Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
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