[src/trunk]: src/usr.bin/sort long align records written to temporary files.

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

details:   https://anonhg.NetBSD.org/src/rev/c03d62e1575e
branches:  trunk
changeset: 747986:c03d62e1575e
user:      dsl <dsl%NetBSD.org@localhost>
date:      Wed Oct 07 21:03:29 2009 +0000

description:
long align records written to temporary files.

diffstat:

 usr.bin/sort/files.c |  24 ++++++++++++++++--------
 1 files changed, 16 insertions(+), 8 deletions(-)

diffs (73 lines):

diff -r 9b271e175f8a -r c03d62e1575e usr.bin/sort/files.c
--- a/usr.bin/sort/files.c      Wed Oct 07 21:02:57 2009 +0000
+++ b/usr.bin/sort/files.c      Wed Oct 07 21:03:29 2009 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: files.c,v 1.39 2009/09/28 20:30:01 dsl Exp $   */
+/*     $NetBSD: files.c,v 1.40 2009/10/07 21:03:29 dsl Exp $   */
 
 /*-
  * Copyright (c) 2000-2003 The NetBSD Foundation, Inc.
@@ -65,12 +65,15 @@
 #include "fsort.h"
 
 #ifndef lint
-__RCSID("$NetBSD: files.c,v 1.39 2009/09/28 20:30:01 dsl Exp $");
+__RCSID("$NetBSD: files.c,v 1.40 2009/10/07 21:03:29 dsl Exp $");
 __SCCSID("@(#)files.c  8.1 (Berkeley) 6/6/93");
 #endif /* not lint */
 
 #include <string.h>
 
+/* Align records in temporary files to avoid misaligned copies */
+#define REC_ROUNDUP(n) (((n) + sizeof (long) - 1) & ~(sizeof (long) - 1))
+
 static ssize_t seq(FILE *, u_char **);
 
 /*
@@ -226,7 +229,7 @@
 void
 putrec(const RECHEADER *rec, FILE *fp)
 {
-       EWRITE(rec, 1, offsetof(RECHEADER, data) + rec->length, fp);
+       EWRITE(rec, 1, REC_ROUNDUP(offsetof(RECHEADER, data) + rec->length), fp);
 }
 
 /*
@@ -244,7 +247,7 @@
 void
 putkeydump(const RECHEADER *rec, FILE *fp)
 {
-       EWRITE(rec, 1, offsetof(RECHEADER, data) + rec->offset, fp);
+       EWRITE(rec, 1, REC_ROUNDUP(offsetof(RECHEADER, data) + rec->offset), fp);
 }
 
 /*
@@ -253,19 +256,24 @@
 int
 geteasy(FILE *fp, RECHEADER *rec, u_char *end, struct field *dummy2)
 {
+       length_t file_len;
        int i;
 
+       (void)sizeof (char[offsetof(RECHEADER, length) == 0 ? 1 : -1]);
+
        if ((u_char *)(rec + 1) > end)
                return (BUFFEND);
-       if (!fread(rec, 1, offsetof(RECHEADER, data), fp)) {
+       if (!fread(&rec->length, 1, sizeof rec->length, fp)) {
                fclose(fp);
                return (EOF);
        }
-       if (end - rec->data < (ptrdiff_t)rec->length) {
-               for (i = offsetof(RECHEADER, data) - 1; i >= 0;  i--)
+       file_len = REC_ROUNDUP(offsetof(RECHEADER, data) + rec->length);
+       if (end - rec->data < (ptrdiff_t)file_len) {
+               for (i = sizeof rec->length - 1; i >= 0;  i--)
                        ungetc(*((char *) rec + i), fp);
                return (BUFFEND);
        }
-       fread(rec->data, rec->length, 1, fp);
+
+       fread(&rec->length + 1, file_len - sizeof rec->length, 1, fp);
        return (0);
 }