From e7539b79f703a6b533385088fc15cb5c9ab3f56f Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 4 Jul 2019 21:16:56 +0100 Subject: [PATCH] drm/i915/gtt: Mark the freed page table entries with scratch On unwinding the allocation error path and having freed the page table entry, it is imperative that we mark it as scratch. <4> [416.075569] general protection fault: 0000 [#1] PREEMPT SMP PTI <4> [416.075801] CPU: 0 PID: 2385 Comm: kworker/u2:11 Tainted: G U 5.2.0-rc7-CI-Patchwork_13534+ #1 <4> [416.076162] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.1-0-g8891697-prebuilt.qemu-project.org 04/01/2014 <4> [416.076522] Workqueue: i915 __i915_vm_release [i915] <4> [416.076754] RIP: 0010:gen8_ppgtt_cleanup_3lvl+0x58/0xb0 [i915] <4> [416.077023] Code: 81 e2 04 fe ff ff 81 c2 ff 01 00 00 4c 8d 74 d6 58 4d 8b 65 00 4d 3b a7 28 02 00 00 74 40 49 8d 5c 24 50 49 81 c4 50 10 00 00 <48> 8b 2b 49 3b af 20 02 00 00 74 13 4c 89 ff 48 89 ee e8 01 fb ff <4> [416.077445] RSP: 0018:ffffc9000046bd98 EFLAGS: 00010206 <4> [416.077625] RAX: 0001000000000000 RBX: 6b6b6b6b6b6b6bbb RCX: 8b4b56d500000000 <4> [416.077838] RDX: 00000000000001ff RSI: ffff88805a578008 RDI: ffff88805bd0efc8 <4> [416.078167] RBP: ffff88805bd0efc8 R08: 0000000004e42b93 R09: 0000000000000001 <4> [416.078381] R10: 0000000000000000 R11: ffff888077a1b0b8 R12: 6b6b6b6b6b6b7bbb <4> [416.078594] R13: ffff88805a578058 R14: ffff88805a579058 R15: ffff88805bd0efc8 <4> [416.078815] FS: 0000000000000000(0000) GS:ffff88807da00000(0000) knlGS:0000000000000000 <4> [416.079395] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 <4> [416.079851] CR2: 000056160fec2b14 CR3: 0000000071bbc003 CR4: 00000000003606f0 <4> [416.080388] Call Trace: <4> [416.080828] gen8_ppgtt_cleanup+0x64/0x100 [i915] <4> [416.081399] __i915_vm_release+0xfc/0x1d0 [i915] Fixes: 1d1b5490b91c ("drm/i915/gtt: Replace struct_mutex serialisation for allocation") Signed-off-by: Chris Wilson Cc: Matthew Auld Cc: Mika Kuoppala Reviewed-by: Matthew Auld Link: https://patchwork.freedesktop.org/patch/msgid/20190704201656.15775-1-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/i915_gem_gtt.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c index 9756f1b670e9..57db2d7270c5 100644 --- a/drivers/gpu/drm/i915/i915_gem_gtt.c +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c @@ -1491,6 +1491,7 @@ unwind_pd: spin_lock(&pdp->lock); if (atomic_dec_and_test(&pd->used)) { gen8_ppgtt_set_pdpe(pdp, vm->scratch_pd, pdpe); + pdp->entry[pdpe] = vm->scratch_pd; GEM_BUG_ON(!atomic_read(&pdp->used)); atomic_dec(&pdp->used); GEM_BUG_ON(alloc); @@ -1567,6 +1568,7 @@ unwind_pdp: spin_lock(&pml4->lock); if (atomic_dec_and_test(&pdp->used)) { gen8_ppgtt_set_pml4e(pml4, vm->scratch_pdp, pml4e); + pml4->entry[pml4e] = vm->scratch_pdp; GEM_BUG_ON(alloc); alloc = pdp; /* defer the free until after the lock */ } -- 2.30.2