Re: [PATCH] drm/xe: Mark xe_vma_ops_alloc() noinline for error injection

[Matthew Brost <matthew.brost@intel.com>]

On Wed, Oct 07, 2026 at 10:24:26PM +0000, Shuicheng Lin wrote:
> Since xe_vma_ops_alloc() was reduced to a loop around
> xe_pt_job_ops_alloc(), the compiler inlines it into all of its
> callers, including xe_vm_bind_ioctl(). ALLOW_ERROR_INJECTION() only
> keeps an out-of-line copy of the function alive for the kprobe, so
> fail_function injection on xe_vma_ops_alloc is armed on a copy that is
> never called and the bind IOCTL succeeds.
> 
> This is seen with the nodebug kernel config used in CI, where
> igt@xe_fault_injection@vm-bind-fail-xe_vma_ops_alloc fails with:
> 
>   Failed assertion: simple_vm_bind(fd, vm) != 0
> 
> Mark xe_vma_ops_alloc() noinline so callers go through the injectable
> function.
> 
> Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/work_items/9432
> Fixes: 0e33330f1238 ("drm/xe: Add struct xe_pt_job_ops")
> Cc: Matthew Brost <matthew.brost@intel.com>

Reviewed-by: Matthew Brost <matthew.brost@intel.com>

> Assisted-by: LLM
> Signed-off-by: Shuicheng Lin <shuicheng.lin@intel.com>
> ---
>  drivers/gpu/drm/xe/xe_vm.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
> index 761bc136145f..8e2110e11368 100644
> --- a/drivers/gpu/drm/xe/xe_vm.c
> +++ b/drivers/gpu/drm/xe/xe_vm.c
> @@ -676,7 +676,7 @@ static void xe_vm_clear_fault_entries(struct xe_vm *vm)
>  	vm->faults.len = 0;
>  }
>  
> -static int xe_vma_ops_alloc(struct xe_vma_ops *vops, bool array_of_binds)
> +static noinline int xe_vma_ops_alloc(struct xe_vma_ops *vops, bool array_of_binds)
>  {
>  	int i;
>  
> -- 
> 2.43.0
>