<!DOCTYPE html> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> </head> <body> <div class="moz-cite-prefix">On 5/7/2024 10:04 AM, Shuicheng Lin wrote: </div> <blockquote type="cite" cite="mid:20240507080456.613786-1-shuicheng.lin@intel.com"> <pre class="moz-quote-pre" wrap="">Here is the failure stack: [ 12.988209] ------------[ cut here ]------------ [ 12.988216] UBSAN: shift-out-of-bounds in ./include/linux/log2.h:57:13 [ 12.988232] shift exponent 64 is too large for 64-bit type 'long unsigned int' [ 12.988235] CPU: 4 PID: 1310 Comm: gnome-shell Tainted: G U 6.9.0-rc6+prerelease1158+ #19 [ 12.988237] Hardware name: Intel Corporation Raptor Lake Client Platform/RPL-S ADP-S DDR5 UDIMM CRB, BIOS RPLSFWI1.R00.3301.A02.2208050712 08/05/2022 [ 12.988239] Call Trace: [ 12.988240] <TASK> [ 12.988242] dump_stack_lvl+0xd7/0xf0 [ 12.988248] dump_stack+0x10/0x20 [ 12.988250] ubsan_epilogue+0x9/0x40 [ 12.988253] __ubsan_handle_shift_out_of_bounds+0x10e/0x170 [ 12.988260] dma_resv_reserve_fences.cold+0x2b/0x48 [ 12.988262] ? ww_mutex_lock_interruptible+0x3c/0x110 [ 12.988267] drm_exec_prepare_obj+0x45/0x60 [drm_exec] [ 12.988271] ? vm_bind_ioctl_ops_execute+0x5b/0x740 [xe] [ 12.988345] vm_bind_ioctl_ops_execute+0x78/0x740 [xe] It is caused by the value 0 of parameter num_fences in function drm_exec_prepare_obj. And lead to in function __rounddown_pow_of_two, "0 - 1" causes the shift-out-of-bounds. For the num_fences, it should be 1 at least. Cc: Matthew Brost <a class="moz-txt-link-rfc2396E" href="mailto:matthew.brost@intel.com"><matthew.brost@intel.com></a> Signed-off-by: Shuicheng Lin <a class="moz-txt-link-rfc2396E" href="mailto:shuicheng.lin@intel.com"><shuicheng.lin@intel.com></a> --- drivers/gpu/drm/xe/xe_vm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c index d17192c8b7de..96cb4d9762a3 100644 --- a/drivers/gpu/drm/xe/xe_vm.c +++ b/drivers/gpu/drm/xe/xe_vm.c @@ -2692,7 +2692,7 @@ static int vma_lock_and_validate(struct drm_exec *exec, struct xe_vma *vma, if (bo) { if (!bo->vm) - err = drm_exec_prepare_obj(exec, &bo->ttm.base, 0); + err = drm_exec_prepare_obj(exec, &bo->ttm.base, 1);</pre> </blockquote> This needs to be fixed in drm_exec_prepare_obj() by checking num_fences and not calling dma_resv_reserve_fences() Regards, Nirmoy <blockquote type="cite" cite="mid:20240507080456.613786-1-shuicheng.lin@intel.com"> <pre class="moz-quote-pre" wrap=""> if (!err && validate) err = xe_bo_validate(bo, xe_vma_vm(vma), true); } @@ -2777,7 +2777,7 @@ static int vm_bind_ioctl_ops_lock_and_prep(struct drm_exec *exec, struct xe_vma_op *op; int err; - err = drm_exec_prepare_obj(exec, xe_vm_obj(vm), 0); + err = drm_exec_prepare_obj(exec, xe_vm_obj(vm), 1); if (err) return err; </pre> </blockquote> </body> </html>