2 * Revision 12: http://theos.com/~deraadt/snprintf.c
4 * Copyright (c) 1997 Theo de Raadt
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 # include <sys/param.h>
30 #include <sys/types.h>
45 #define roundup(x, y) ((((x)+((y)-1))/(y))*(y))
49 #define size_t ssize_t
55 static sigjmp_buf bail;
57 #define EXTRABYTES 2 /* XXX: why 2? you don't want to know */
69 pgsize = getpagesize();
70 curobj = (char *)malloc(n + EXTRABYTES + pgsize * 2);
73 e = curobj + n + EXTRABYTES;
74 e = (char *)roundup((unsigned long)e, pgsize);
75 if (mprotect(e, pgsize, PROT_NONE) == -1) {
80 e = e - n - EXTRABYTES;
99 if (mprotect((caddr_t)(p + n + EXTRABYTES), pgsize,
100 PROT_READ|PROT_WRITE|PROT_EXEC) == -1)
101 mprotect((caddr_t)(p + n + EXTRABYTES), pgsize,
102 PROT_READ|PROT_WRITE);
108 vsnprintf(char *str, size_t n, char const *fmt, va_list ap)
110 vsnprintf(str, n, fmt, ap)
117 struct sigaction osa, nsa;
119 int ret = n + 1; /* if we bail, indicated we overflowed */
121 memset(&nsa, 0, sizeof nsa);
122 nsa.sa_handler = mcatch;
123 sigemptyset(&nsa.sa_mask);
130 if (sigsetjmp(bail, 1) == 0) {
131 if (sigaction(SIGSEGV, &nsa, &osa) == -1) {
135 ret = vsprintf(p, fmt, ap);
138 (void) sigaction(SIGSEGV, &osa, NULL);
144 snprintf(char *str, size_t n, char const *fmt, ...)
146 snprintf(str, n, fmt, va_alist)
160 return (vsnprintf(str, n, fmt, ap));