/* * Copyright (c) 2015, Linaro Limited, Shannon Zhao * * This program is free software; you can redistribute it and/or modify it * under the terms and conditions of the GNU General Public License, * version 2, as published by the Free Software Foundation. * * This program is distributed in the hope it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for * more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see . */ #include #include #include #include #include #include #include static int xen_unmap_device_mmio(const struct resource *resources, unsigned int count) { unsigned int i, j, nr; int rc = 0; const struct resource *r; struct xen_remove_from_physmap xrp; for (i = 0; i < count; i++) { r = &resources[i]; nr = DIV_ROUND_UP(resource_size(r), XEN_PAGE_SIZE); if ((resource_type(r) != IORESOURCE_MEM) || (nr == 0)) continue; for (j = 0; j < nr; j++) { xrp.domid = DOMID_SELF; xrp.gpfn = XEN_PFN_DOWN(r->start) + j; rc = HYPERVISOR_memory_op(XENMEM_remove_from_physmap, &xrp); if (rc) return rc; } } return rc; } static int xen_map_device_mmio(const struct resource *resources, unsigned int count) { unsigned int i, j, nr; int rc = 0; const struct resource *r; xen_pfn_t *gpfns; xen_ulong_t *idxs; int *errs; for (i = 0; i < count; i++) { struct xen_add_to_physmap_range xatp = { .domid = DOMID_SELF, .space = XENMAPSPACE_dev_mmio }; r = &resources[i]; nr = DIV_ROUND_UP(resource_size(r), XEN_PAGE_SIZE); if ((resource_type(r) != IORESOURCE_MEM) || (nr == 0)) continue; gpfns = kzalloc(sizeof(xen_pfn_t) * nr, GFP_KERNEL); idxs = kzalloc(sizeof(xen_ulong_t) * nr, GFP_KERNEL); errs = kzalloc(sizeof(int) * nr, GFP_KERNEL); if (!gpfns || !idxs || !errs) { kfree(gpfns); kfree(idxs); kfree(errs); rc = -ENOMEM; goto unmap; } for (j = 0; j < nr; j++) { /* * The regions are always mapped 1:1 to DOM0 and this is * fine because the memory map for DOM0 is the same as * the host (except for the RAM). */ gpfns[j] = XEN_PFN_DOWN(r->start) + j; idxs[j] = XEN_PFN_DOWN(r->start) + j; } xatp.size = nr; set_xen_guest_handle(xatp.gpfns, gpfns); set_xen_guest_handle(xatp.idxs, idxs); set_xen_guest_handle(xatp.errs, errs); rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap_range, &xatp); kfree(gpfns); kfree(idxs); kfree(errs); if (rc) goto unmap; } return rc; unmap: xen_unmap_device_mmio(resources, i); return rc; } static int xen_platform_notifier(struct notifier_block *nb, unsigned long action, void *data) { struct platform_device *pdev = to_platform_device(data); int r = 0; if (pdev->num_resources == 0 || pdev->resource == NULL) return NOTIFY_OK; switch (action) { case BUS_NOTIFY_ADD_DEVICE: r = xen_map_device_mmio(pdev->resource, pdev->num_resources); break; case BUS_NOTIFY_DEL_DEVICE: r = xen_unmap_device_mmio(pdev->resource, pdev->num_resources); break; default: return NOTIFY_DONE; } if (r) dev_err(&pdev->dev, "Platform: Failed to %s device %s MMIO!\n", action == BUS_NOTIFY_ADD_DEVICE ? "map" : (action == BUS_NOTIFY_DEL_DEVICE ? "unmap" : "?"), pdev->name); return NOTIFY_OK; } static struct notifier_block platform_device_nb = { .notifier_call = xen_platform_notifier, }; static int __init register_xen_platform_notifier(void) { if (!xen_initial_domain() || acpi_disabled) return 0; return bus_register_notifier(&platform_bus_type, &platform_device_nb); } arch_initcall(register_xen_platform_notifier); #ifdef CONFIG_ARM_AMBA #include static int xen_amba_notifier(struct notifier_block *nb, unsigned long action, void *data) { struct amba_device *adev = to_amba_device(data); int r = 0; switch (action) { case BUS_NOTIFY_ADD_DEVICE: r = xen_map_device_mmio(&adev->res, 1); break; case BUS_NOTIFY_DEL_DEVICE: r = xen_unmap_device_mmio(&adev->res, 1); break; default: return NOTIFY_DONE; } if (r) dev_err(&adev->dev, "AMBA: Failed to %s device %s MMIO!\n", action == BUS_NOTIFY_ADD_DEVICE ? "map" : (action == BUS_NOTIFY_DEL_DEVICE ? "unmap" : "?"), adev->dev.init_name); return NOTIFY_OK; } static struct notifier_block amba_device_nb = { .notifier_call = xen_amba_notifier, }; static int __init register_xen_amba_notifier(void) { if (!xen_initial_domain() || acpi_disabled) return 0; return bus_register_notifier(&amba_bustype, &amba_device_nb); } arch_initcall(register_xen_amba_notifier); #endif s <torvalds@linux-foundation.org>2017-01-29 13:50:06 -0800 commit39cb2c9a316e77f6dfba96c543e55b6672d5a37e (patch) tree98fe974ee4e20121253de7f61fc8d01bdb3821c1 /include/uapi/drm/armada_drm.h parent2c5d9555d6d937966d79d4c6529a5f7b9206e405 (diff)
drm/i915: Check for NULL i915_vma in intel_unpin_fb_obj()
I've seen this trigger twice now, where the i915_gem_object_to_ggtt() call in intel_unpin_fb_obj() returns NULL, resulting in an oops immediately afterwards as the (inlined) call to i915_vma_unpin_fence() tries to dereference it. It seems to be some race condition where the object is going away at shutdown time, since both times happened when shutting down the X server. The call chains were different: - VT ioctl(KDSETMODE, KD_TEXT): intel_cleanup_plane_fb+0x5b/0xa0 [i915] drm_atomic_helper_cleanup_planes+0x6f/0x90 [drm_kms_helper] intel_atomic_commit_tail+0x749/0xfe0 [i915] intel_atomic_commit+0x3cb/0x4f0 [i915] drm_atomic_commit+0x4b/0x50 [drm] restore_fbdev_mode+0x14c/0x2a0 [drm_kms_helper] drm_fb_helper_restore_fbdev_mode_unlocked+0x34/0x80 [drm_kms_helper] drm_fb_helper_set_par+0x2d/0x60 [drm_kms_helper] intel_fbdev_set_par+0x18/0x70 [i915] fb_set_var+0x236/0x460 fbcon_blank+0x30f/0x350 do_unblank_screen+0xd2/0x1a0 vt_ioctl+0x507/0x12a0 tty_ioctl+0x355/0xc30 do_vfs_ioctl+0xa3/0x5e0 SyS_ioctl+0x79/0x90 entry_SYSCALL_64_fastpath+0x13/0x94 - i915 unpin_work workqueue: intel_unpin_work_fn+0x58/0x140 [i915] process_one_work+0x1f1/0x480 worker_thread+0x48/0x4d0 kthread+0x101/0x140 and this patch purely papers over the issue by adding a NULL pointer check and a WARN_ON_ONCE() to avoid the oops that would then generally make the machine unresponsive. Other callers of i915_gem_object_to_ggtt() seem to also check for the returned pointer being NULL and warn about it, so this clearly has happened before in other places. [ Reported it originally to the i915 developers on Jan 8, applying the ugly workaround on my own now after triggering the problem for the second time with no feedback. This is likely to be the same bug reported as https://bugs.freedesktop.org/show_bug.cgi?id=98829 https://bugs.freedesktop.org/show_bug.cgi?id=99134 which has a patch for the underlying problem, but it hasn't gotten to me, so I'm applying the workaround. ] Cc: Daniel Vetter <daniel.vetter@intel.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Imre Deak <imre.deak@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/uapi/drm/armada_drm.h')