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/* $OpenBSD: siginfo-fault.c,v 1.6 2017/07/22 16:12:27 kettenis Exp $ */
/*
* Copyright (c) 2014 Google Inc.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/mman.h>
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <setjmp.h>
#include <signal.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
/*
* Some architectures deliver an imprecise fault address.
*/
#ifdef __sparc64__
#define EXPADDR_MASK ~(3UL)
#else
#define EXPADDR_MASK ~(0UL)
#endif
#define CHECK_EQ(a, b) assert((a) == (b))
#define CHECK_NE(a, b) assert((a) != (b))
#define CHECK_LE(a, b) assert((a) <= (b))
#define FAIL() assert(0)
static jmp_buf env;
static volatile int gotsigno;
static volatile siginfo_t gotsi;
static void
sigsegv(int signo, siginfo_t *si, void *ctx)
{
gotsigno = signo;
gotsi = *si;
siglongjmp(env, 1);
}
static const char *
strsigcode(int signum, int sigcode)
{
switch (signum) {
case SIGSEGV:
switch (sigcode) {
case SEGV_MAPERR:
return "address not mapped to object";
case SEGV_ACCERR:
return "invalid permissions";
}
break;
case SIGBUS:
switch (sigcode) {
case BUS_ADRALN:
return "invalid address alignment";
case BUS_ADRERR:
return "non-existent physical address";
case BUS_OBJERR:
return "object specific hardware error";
}
break;
}
return "unknown";
}
static int
checksig(const char *name, int expsigno, int expcode, volatile char *expaddr)
{
int fail = 0;
char str1[NL_TEXTMAX], str2[NL_TEXTMAX];
expaddr = (char *)((uintptr_t)expaddr & EXPADDR_MASK);
if (expsigno != gotsigno) {
strlcpy(str1, strsignal(expsigno), sizeof(str1));
strlcpy(str2, strsignal(gotsigno), sizeof(str2));
fprintf(stderr, "%s signo: expect %d (%s), actual %d (%s)\n",
name, expsigno, str1, gotsigno, str2);
++fail;
}
if (expsigno != gotsi.si_signo) {
strlcpy(str1, strsignal(expsigno), sizeof(str1));
strlcpy(str2, strsignal(gotsi.si_signo), sizeof(str2));
fprintf(stderr, "%s si_signo: expect %d (%s), actual %d (%s)\n",
name, expsigno, str1, gotsi.si_signo, str2);
++fail;
}
if (expcode != gotsi.si_code) {
fprintf(stderr, "%s si_code: expect %d (%s), actual %d (%s)\n",
name, expcode, strsigcode(expsigno, expcode),
gotsi.si_code, strsigcode(gotsigno, gotsi.si_code));
++fail;
}
if (expaddr != gotsi.si_addr) {
fprintf(stderr, "%s si_addr: expect %p, actual %p\n",
name, expaddr, gotsi.si_addr);
++fail;
}
return (fail);
}
int
main()
{
int fail = 0;
long pagesize = sysconf(_SC_PAGESIZE);
CHECK_NE(-1, pagesize);
const struct sigaction sa = {
.sa_sigaction = sigsegv,
.sa_flags = SA_SIGINFO,
};
CHECK_EQ(0, sigaction(SIGSEGV, &sa, NULL));
CHECK_EQ(0, sigaction(SIGBUS, &sa, NULL));
volatile char *p;
CHECK_NE(MAP_FAILED, (p = mmap(NULL, pagesize, PROT_NONE,
MAP_PRIVATE|MAP_ANON, -1, 0)));
CHECK_EQ(0, mprotect((void *)p, pagesize, PROT_READ));
if (sigsetjmp(env, 1) == 0) {
p[0] = 1;
FAIL();
}
fail += checksig("mprotect read", SIGSEGV, SEGV_ACCERR, p);
CHECK_EQ(0, mprotect((void *)p, pagesize, PROT_NONE));
if (sigsetjmp(env, 1) == 0) {
(void)p[1];
FAIL();
}
fail += checksig("mprotect none", SIGSEGV, SEGV_ACCERR, p + 1);
CHECK_EQ(0, munmap((void *)p, pagesize));
if (sigsetjmp(env, 1) == 0) {
(void)p[2];
FAIL();
}
fail += checksig("munmap", SIGSEGV, SEGV_MAPERR, p + 2);
char filename[] = "/tmp/siginfo-fault.XXXXXXXX";
int fd;
CHECK_LE(0, (fd = mkstemp(filename)));
CHECK_EQ(0, unlink(filename));
CHECK_EQ(0, ftruncate(fd, 0)); /* just in case */
CHECK_NE(MAP_FAILED, (p = mmap(NULL, pagesize, PROT_READ|PROT_WRITE,
MAP_SHARED, fd, 0)));
CHECK_EQ(0, close(fd));
if (sigsetjmp(env, 1) == 0) {
p[3] = 1;
FAIL();
}
fail += checksig("mmap file", SIGBUS, BUS_OBJERR, p + 3);
return (fail);
}
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