Our mmap(2) has a limitation where the `offset' parameter must be
page-aligned. cmp(1) should know about this flaw, and work around it. While i was at it, fixed an uninitialized variable as reported by -Wall.
This commit is contained in:
parent
b8b15e71f7
commit
c28065c606
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=21429
@ -44,9 +44,12 @@ static char sccsid[] = "@(#)regular.c 8.3 (Berkeley) 4/2/94";
|
||||
#include <stdlib.h>
|
||||
#include <stdio.h>
|
||||
#include <string.h>
|
||||
#include <unistd.h>
|
||||
|
||||
#include "extern.h"
|
||||
|
||||
#define ROUNDPAGE(i) ((i) & ~pagemask)
|
||||
|
||||
void
|
||||
c_regular(fd1, file1, skip1, len1, fd2, file2, skip2, len2)
|
||||
int fd1, fd2;
|
||||
@ -56,6 +59,7 @@ c_regular(fd1, file1, skip1, len1, fd2, file2, skip2, len2)
|
||||
u_char ch, *p1, *p2;
|
||||
off_t byte, length, line;
|
||||
int dfound;
|
||||
off_t pagemask, off1, off2;
|
||||
|
||||
if (sflag && len1 != len2)
|
||||
exit(1);
|
||||
@ -67,21 +71,27 @@ c_regular(fd1, file1, skip1, len1, fd2, file2, skip2, len2)
|
||||
eofmsg(file2);
|
||||
len2 -= skip2;
|
||||
|
||||
pagemask = (off_t)getpagesize() - 1;
|
||||
off1 = ROUNDPAGE(skip1);
|
||||
off2 = ROUNDPAGE(skip2);
|
||||
|
||||
length = MIN(len1, len2);
|
||||
if (length > SIZE_T_MAX)
|
||||
return (c_special(fd1, file1, skip1, fd2, file2, skip2));
|
||||
|
||||
if ((p1 = (u_char *)mmap(NULL,
|
||||
(size_t)length, PROT_READ, 0, fd1, skip1)) == (u_char *)-1)
|
||||
(size_t)length, PROT_READ, 0, fd1, off1)) == (u_char *)-1)
|
||||
err(ERR_EXIT, "%s", file1);
|
||||
|
||||
madvise(p1, length, MADV_SEQUENTIAL);
|
||||
if ((p2 = (u_char *)mmap(NULL,
|
||||
(size_t)length, PROT_READ, 0, fd2, skip2)) == (u_char *)-1)
|
||||
(size_t)length, PROT_READ, 0, fd2, off2)) == (u_char *)-1)
|
||||
err(ERR_EXIT, "%s", file2);
|
||||
madvise(p2, length, MADV_SEQUENTIAL);
|
||||
|
||||
dfound = 0;
|
||||
p1 += skip1 - off1;
|
||||
p2 += skip2 - off2;
|
||||
for (byte = line = 1; length--; ++p1, ++p2, ++byte) {
|
||||
if ((ch = *p1) != *p2)
|
||||
if (lflag) {
|
||||
|
@ -60,6 +60,7 @@ c_special(fd1, file1, skip1, fd2, file2, skip2)
|
||||
if ((fp2 = fdopen(fd2, "r")) == NULL)
|
||||
err(ERR_EXIT, "%s", file2);
|
||||
|
||||
dfound = 0;
|
||||
while (skip1--)
|
||||
if (getc(fp1) == EOF)
|
||||
goto eof;
|
||||
@ -67,7 +68,6 @@ c_special(fd1, file1, skip1, fd2, file2, skip2)
|
||||
if (getc(fp2) == EOF)
|
||||
goto eof;
|
||||
|
||||
dfound = 0;
|
||||
for (byte = line = 1;; ++byte) {
|
||||
ch1 = getc(fp1);
|
||||
ch2 = getc(fp2);
|
||||
|
Loading…
Reference in New Issue
Block a user