Remove stale comment

There's no useracc here, and even if there was it shouldn't be here. vmapbuf is
sufficient and as the comment says, useracc is racy.

This commit is contained in:

Warner Losh

2020-04-13 21:03:30 +00:00

parent 64c4dfcd26

commit 450a2e2a12

1 changed files with 1 additions and 8 deletions

									
										sys/cam/cam_periph.c
									
		+1
		-8
	
												View File
												
				@@ -971,14 +971,7 @@ cam_periph_mapmem(union ccb *ccb, struct cam_periph_map_info *mapinfo,

						mapinfo->bp[i]->b_iocmd = (dirs[i] == CAM_DIR_OUT) ?

						    BIO_WRITE : BIO_READ;

						/*

						 * Map the buffer into kernel memory.

						 *

						 * Note that useracc() alone is not a  sufficient test.

						 * vmapbuf() can still fail due to a smaller file mapped

						 * into a larger area of VM, or if userland races against

						 * vmapbuf() after the useracc() check.

						 */

						/* Map the buffer into kernel memory. */

						if (vmapbuf(mapinfo->bp[i], 1) < 0) {

							uma_zfree(pbuf_zone, mapinfo->bp[i]);

							goto fail;