[src/netbsd-1-5]: src/usr.bin/cmp do not mmap() with MAP_PRIVATE - it's not n...

[jdolecek <jdolecek%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/c3cc220323e4
branches:  netbsd-1-5
changeset: 488604:c3cc220323e4
user:      jdolecek <jdolecek%NetBSD.org@localhost>
date:      Thu Jul 20 19:06:09 2000 +0000

description:
do not mmap() with MAP_PRIVATE - it's not needed for cmp(1) and causes
memory shortage for bigger files.

This fixes bin/10625 by Uwe Klaus.

While here, change the code to fallback to classic stdio in (now unlikely)
case mmap() fails.

diffstat:

 usr.bin/cmp/regular.c |  22 ++++++++++++++--------
 1 files changed, 14 insertions(+), 8 deletions(-)

diffs (47 lines):

diff -r 99547c27185d -r c3cc220323e4 usr.bin/cmp/regular.c
--- a/usr.bin/cmp/regular.c     Thu Jul 20 18:48:57 2000 +0000
+++ b/usr.bin/cmp/regular.c     Thu Jul 20 19:06:09 2000 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: regular.c,v 1.8 2000/03/20 18:23:26 kleink Exp $       */
+/*     $NetBSD: regular.c,v 1.8.4.1 2000/07/20 19:06:09 jdolecek Exp $ */
 
 /*-
  * Copyright (c) 1991, 1993, 1994
@@ -38,7 +38,7 @@
 #if 0
 static char sccsid[] = "@(#)regular.c  8.3 (Berkeley) 4/2/94";
 #else
-__RCSID("$NetBSD: regular.c,v 1.8 2000/03/20 18:23:26 kleink Exp $");
+__RCSID("$NetBSD: regular.c,v 1.8.4.1 2000/07/20 19:06:09 jdolecek Exp $");
 #endif
 #endif /* not lint */
 
@@ -75,16 +75,22 @@
        len2 -= skip2;
 
        length = MIN(len1, len2);
-       if (length > SIZE_T_MAX)
-               return (c_special(fd1, file1, skip1, fd2, file2, skip2));
+       if (length > SIZE_T_MAX) {
+mmap_failed:
+               c_special(fd1, file1, skip1, fd2, file2, skip2);
+               return;
+       }
 
        if ((p1 = (u_char *)mmap(NULL, (size_t)length,
-           PROT_READ, MAP_PRIVATE|MAP_FILE, fd1, skip1)) == MAP_FAILED)
-               err(ERR_EXIT, "%s", file1);
+           PROT_READ, MAP_FILE, fd1, skip1)) == MAP_FAILED)
+               goto mmap_failed;
        (void)madvise(p1, (size_t)length, MADV_SEQUENTIAL);
+
        if ((p2 = (u_char *)mmap(NULL, (size_t)length,
-           PROT_READ, MAP_PRIVATE|MAP_FILE, fd2, skip2)) == MAP_FAILED)
-               err(ERR_EXIT, "%s", file2);
+           PROT_READ, MAP_FILE, fd2, skip2)) == MAP_FAILED) {
+               munmap(p1, (size_t) length);
+               goto mmap_failed;
+       }
        (void)madvise(p2, (size_t)length, MADV_SEQUENTIAL);
 
        dfound = 0;