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authorThomas Hellström <thomas.hellstrom@linux.intel.com>2024-02-08 14:21:15 +0100
committerThomas Hellström <thomas.hellstrom@linux.intel.com>2024-02-15 09:53:00 +0100
commit9377de4cb3e8fb6c494fa2f5ae2c3780d3e73822 (patch)
tree4ebad664d4dc28d8b4a45d23a691ebf3fe23055a
parentbf4c27b8267d7848bb81fd41e6aa07aa662f07fb (diff)
downloadasm-generic-9377de4cb3e8fb6c494fa2f5ae2c3780d3e73822.tar.gz
drm/xe/vm: Avoid reserving zero fences
The function xe_vm_prepare_vma was blindly accepting zero as the number of fences and forwarded that to drm_exec_prepare_obj. However, that leads to an out-of-bounds shift in the dma_resv_reserve_fences() and while one could argue that the dma_resv code should be robust against that, avoid attempting to reserve zero fences. Relevant stack trace: [773.183188] ------------[ cut here ]------------ [773.183199] UBSAN: shift-out-of-bounds in ../include/linux/log2.h:57:13 [773.183241] shift exponent 64 is too large for 64-bit type 'long unsigned int' [773.183254] CPU: 2 PID: 1816 Comm: xe_evict Tainted: G U 6.8.0-rc3-xe #1 [773.183256] Hardware name: ASUS System Product Name/PRIME Z690-P D4, BIOS 2014 10/14/2022 [773.183257] Call Trace: [773.183258] <TASK> [773.183260] dump_stack_lvl+0xaf/0xd0 [773.183266] dump_stack+0x10/0x20 [773.183283] ubsan_epilogue+0x9/0x40 [773.183286] __ubsan_handle_shift_out_of_bounds+0x10f/0x170 [773.183293] dma_resv_reserve_fences.cold+0x2b/0x48 [773.183295] ? ww_mutex_lock+0x3c/0x110 [773.183301] drm_exec_prepare_obj+0x45/0x60 [drm_exec] [773.183313] xe_vm_prepare_vma+0x33/0x70 [xe] [773.183375] xe_vma_destroy_unlocked+0x55/0xa0 [xe] [773.183427] xe_vm_close_and_put+0x526/0x940 [xe] Fixes: 2714d5093620 ("drm/xe: Convert pagefaulting code to use drm_exec") Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> Reviewed-by: Matthew Auld <matthew.auld@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20240208132115.3132-1-thomas.hellstrom@linux.intel.com (cherry picked from commit eb538b5574251a449f40b1ee35efc631228c8992) Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
-rw-r--r--drivers/gpu/drm/xe/xe_vm.c13
1 files changed, 10 insertions, 3 deletions
diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
index 865e10d0a06aa3..7b00faa672879c 100644
--- a/drivers/gpu/drm/xe/xe_vm.c
+++ b/drivers/gpu/drm/xe/xe_vm.c
@@ -995,9 +995,16 @@ int xe_vm_prepare_vma(struct drm_exec *exec, struct xe_vma *vma,
int err;
XE_WARN_ON(!vm);
- err = drm_exec_prepare_obj(exec, xe_vm_obj(vm), num_shared);
- if (!err && bo && !bo->vm)
- err = drm_exec_prepare_obj(exec, &bo->ttm.base, num_shared);
+ if (num_shared)
+ err = drm_exec_prepare_obj(exec, xe_vm_obj(vm), num_shared);
+ else
+ err = drm_exec_lock_obj(exec, xe_vm_obj(vm));
+ if (!err && bo && !bo->vm) {
+ if (num_shared)
+ err = drm_exec_prepare_obj(exec, &bo->ttm.base, num_shared);
+ else
+ err = drm_exec_lock_obj(exec, &bo->ttm.base);
+ }
return err;
}