[PATCH v2 2/3] fs: create helper file_user_path() for user displayed mapped file path

[Al Viro]

On Sat, Oct 07, 2023 at 11:44:32AM +0300, Amir Goldstein wrote:

> @@ -93,7 +93,8 @@ static void show_faulting_vma(unsigned long address)
>  		char *nm = "?";
>  
>  		if (vma->vm_file) {
> -			nm = file_path(vma->vm_file, buf, ARC_PATH_MAX-1);
> +			nm = d_path(file_user_path(vma->vm_file), buf,
> +				    ARC_PATH_MAX-1);
>  			if (IS_ERR(nm))
>  				nm = "?";

Umm...  At one point I considered this:
	if (vma->vm_file)
                pr_info("  @off 0x%lx in [%pD]  VMA: 0x%08lx to 0x%08lx\n",
                        vma->vm_start < TASK_UNMAPPED_BASE ?
                                address : address - vma->vm_start,
                        vma->vm_file, vma->vm_start, vma->vm_end);
	else
                pr_info("  @off 0x%lx in [anon]  VMA: 0x%08lx to 0x%08lx\n",
                        vma->vm_start < TASK_UNMAPPED_BASE ?
                                address : address - vma->vm_start,
                        vma->vm_start, vma->vm_end);
and to hell with that 'buf' thing...