int __libc_start_main (int (*main) (int, char **, char **),
int argc, char **argv,
void (*init) (void), void (*fini) (void),
void (*rtld_fini) (void), void *stack_end)
{
char **envp = argv + argc + 1;
int result = main (argc, argv, envp);
mtcp_sys_exit(result);
while(1);
}
int __libc_start_main (int (*main) (int, char **, char **),
int argc, char **argv,
void (*init) (void), void (*fini) (void),
void (*rtld_fini) (void), void *stack_end)
{
int mtcp_sys_errno;
char **envp = argv + argc + 1;
int result = main(argc, argv, envp);
mtcp_sys_exit(result);
(void)mtcp_sys_errno; /* Stop compiler warning about unused variable */
while(1);
}
NO_OPTIMIZE
int main(int argc, char *argv[], char **environ)
{
char *ckptImage = NULL;
MtcpHeader mtcpHdr;
int mtcp_sys_errno;
int simulate = 0;
if (argc == 1) {
MTCP_PRINTF("***ERROR: This program should not be used directly.\n");
mtcp_sys_exit(1);
}
#if 0
MTCP_PRINTF("Attach for debugging.");
{int x=1; while(x);}
#endif
// TODO(karya0): Remove vDSO checks after 2.4.0-rc3 release, and after testing.
// Without mtcp_check_vdso, CentOS 7 fails on dmtcp3, dmtcp5, others.
#define ENABLE_VDSO_CHECK
// TODO(karya0): Remove this block and the corresponding file after sufficient
// testing: including testing for __i386__, __arm__ and __aarch64__
#ifdef ENABLE_VDSO_CHECK
/* i386 uses random addresses for vdso. Make sure that its location
* will not conflict with other memory regions.
* (Other arch's may also need this in the future. So, we do it for all.)
* Note that we may need to keep the old and the new vdso. We may
* have checkpointed inside gettimeofday inside the old vdso, and the
* kernel, on restart, knows only the new vdso.
*/
mtcp_check_vdso(environ);
#endif
rinfo.fd = -1;
rinfo.use_gdb = 0;
rinfo.text_offset = -1;
shift;
while (argc > 0) {
// Flags for standalone debugging
if (argc == 1) {
// We would use MTCP_PRINTF, but it's also for output of util/readdmtcp.sh
mtcp_printf("Considering '%s' as a ckpt image.\n", argv[0]);
ckptImage = argv[0];
break;
} else if (mtcp_strcmp(argv[0], "--use-gdb") == 0) {
rinfo.use_gdb = 1;
shift;
} else if (mtcp_strcmp(argv[0], "--text-offset") == 0) {
rinfo.text_offset = mtcp_strtol(argv[1]);
shift; shift;
// Flags for call by dmtcp_restart follow here:
} else if (mtcp_strcmp(argv[0], "--fd") == 0) {
rinfo.fd = mtcp_strtol(argv[1]);
shift; shift;
} else if (mtcp_strcmp(argv[0], "--stderr-fd") == 0) {
rinfo.stderr_fd = mtcp_strtol(argv[1]);
shift; shift;
} else if (mtcp_strcmp(argv[0], "--simulate") == 0) {
simulate = 1;
shift;
} else {
MTCP_PRINTF("MTCP Internal Error\n");
return -1;
}
}
if ((rinfo.fd != -1) ^ (ckptImage == NULL)) {
MTCP_PRINTF("***MTCP Internal Error\n");
mtcp_abort();
}
if (rinfo.fd != -1) {
mtcp_readfile(rinfo.fd, &mtcpHdr, sizeof mtcpHdr);
} else {
int rc = -1;
rinfo.fd = mtcp_sys_open2(ckptImage, O_RDONLY);
if (rinfo.fd == -1) {
MTCP_PRINTF("***ERROR opening ckpt image (%s); errno: %d\n",
ckptImage, mtcp_sys_errno);
mtcp_abort();
}
// This assumes that the MTCP header signature is unique.
// We repeatedly look for mtcpHdr because the first header will be
// for DMTCP. So, we look deeper for the MTCP header. The MTCP
// header is guaranteed to start on an offset that's an integer
// multiple of sizeof(mtcpHdr), which is currently 4096 bytes.
do {
rc = mtcp_readfile(rinfo.fd, &mtcpHdr, sizeof mtcpHdr);
} while (rc > 0 && mtcp_strcmp(mtcpHdr.signature, MTCP_SIGNATURE) != 0);
if (rc == 0) { /* if end of file */
MTCP_PRINTF("***ERROR: ckpt image doesn't match MTCP_SIGNATURE\n");
return 1; /* exit with error code 1 */
}
}
DPRINTF("For debugging:\n"
" (gdb) add-symbol-file ../../bin/mtcp_restart %p\n",
mtcpHdr.restore_addr + rinfo.text_offset);
if (rinfo.text_offset == -1)
DPRINTF("... but add to the above the result, 1 +"
" `text_offset.sh mtcp_restart`\n in the mtcp subdirectory.\n");
if (simulate) {
mtcp_simulateread(rinfo.fd, &mtcpHdr);
return 0;
}
rinfo.saved_brk = mtcpHdr.saved_brk;
rinfo.restore_addr = mtcpHdr.restore_addr;
rinfo.restore_end = mtcpHdr.restore_addr + mtcpHdr.restore_size;
rinfo.restore_size = mtcpHdr.restore_size;
rinfo.vdsoStart = mtcpHdr.vdsoStart;
rinfo.vdsoEnd = mtcpHdr.vdsoEnd;
rinfo.vvarStart = mtcpHdr.vvarStart;
rinfo.vvarEnd = mtcpHdr.vvarEnd;
rinfo.post_restart = mtcpHdr.post_restart;
rinfo.motherofall_tls_info = mtcpHdr.motherofall_tls_info;
rinfo.tls_pid_offset = mtcpHdr.tls_pid_offset;
rinfo.tls_tid_offset = mtcpHdr.tls_tid_offset;
rinfo.myinfo_gs = mtcpHdr.myinfo_gs;
restore_brk(rinfo.saved_brk, rinfo.restore_addr,
rinfo.restore_addr + rinfo.restore_size);
getTextAddr(&rinfo.text_addr, &rinfo.text_size);
if (hasOverlappingMapping(rinfo.restore_addr, rinfo.restore_size)) {
MTCP_PRINTF("*** Not Implemented.\n\n");
mtcp_abort();
restart_slow_path();
} else {
restart_fast_path();
}
return 0; /* Will not reach here, but need to satisfy the compiler */
}
