svn commit: r318565 - head/usr.bin/grep

[Ed Maste]

Author: emaste
Date: Sat May 20 00:42:47 2017
New Revision: 318565
URL: https://svnweb.freebsd.org/changeset/base/318565

Log:
  bsdgrep: fix segfault with --mmap
  
  r313948 partially fixed --mmap behavior but was incomplete.  This commit
  generally reverts it and does it the more correct way- by just consuming
  the rest of the buffer and moving on.
  
  PR:		219402
  Submitted by:	Kyle Evans <kevans91 at ksu.edu>
  Reviewed by:	cem
  Differential Revision:	https://reviews.freebsd.org/D10820

Modified:
  head/usr.bin/grep/file.c

Modified: head/usr.bin/grep/file.c
==============================================================================
--- head/usr.bin/grep/file.c	Sat May 20 00:41:12 2017	(r318564)
+++ head/usr.bin/grep/file.c	Sat May 20 00:42:47 2017	(r318565)
@@ -213,24 +213,24 @@ grep_fgetln(struct file *f, size_t *lenp
 		if (grep_lnbufgrow(len + LNBUFBUMP))
 			goto error;
 		memcpy(lnbuf + off, bufpos, len - off);
+		/* With FILE_MMAP, this is EOF; there's no more to refill */
+		if (filebehave == FILE_MMAP) {
+			bufrem -= len;
+			break;
+		}
 		off = len;
+		/* Fetch more to try and find EOL/EOF */
 		if (grep_refill(f) != 0)
 			goto error;
 		if (bufrem == 0)
 			/* EOF: return partial line */
 			break;
-		if ((p = memchr(bufpos, fileeol, bufrem)) == NULL &&
-		    filebehave != FILE_MMAP)
+		if ((p = memchr(bufpos, fileeol, bufrem)) == NULL)
 			continue;
-		if (p == NULL) {
-			/* mmap EOF: return partial line, consume buffer */
-			diff = len;
-		} else {
-			/* got it: finish up the line (like code above) */
-			++p;
-			diff = p - bufpos;
-			len += diff;
-		}
+		/* got it: finish up the line (like code above) */
+		++p;
+		diff = p - bufpos;
+		len += diff;
 		if (grep_lnbufgrow(len))
 		    goto error;
 		memcpy(lnbuf + off, bufpos, diff);