#include <stdarg.h>
#include <sys/param.h>
#include <fcntl.h>
+#include <signal.h>
#include <sys/resource.h>
#include <sys/wait.h>
#include <sys/stat.h>
#endif
#include "ptrace.h"
+#include "printsiginfo.h"
/* In some libc, these aren't declared. Do it ourself: */
extern char **environ;
#endif /* HAVE_STERRROR */
static void
-usage(FILE *ofp, int exitval)
+usage()
{
- fprintf(ofp, "\
-usage: strace [-CdffhiqrtttTvVxxy] [-I n] [-e expr]...\n\
+ printf("\
+usage: strace [-CdffhiqrtttTvVwxxy] [-I n] [-e expr]...\n\
[-a column] [-o file] [-s strsize] [-P path]...\n\
-p pid... / [-D] [-E var=val]... [-u username] PROG [ARGS]\n\
- or: strace -c[df] [-I n] [-e expr]... [-O overhead] [-S sortby]\n\
+ or: strace -c[dfw] [-I n] [-e expr]... [-O overhead] [-S sortby]\n\
-p pid... / [-D] [-E var=val]... [-u username] PROG [ARGS]\n\
--c -- count time, calls, and errors for each syscall and report summary\n\
--C -- like -c but also print regular output\n\
--w -- summarise syscall latency (default is system time)\n\
--d -- enable debug output to stderr\n\
--D -- run tracer process as a detached grandchild, not as parent\n\
--f -- follow forks, -ff -- with output into separate files\n\
--i -- print instruction pointer at time of syscall\n\
--q -- suppress messages about attaching, detaching, etc.\n\
--r -- print relative timestamp, -t -- absolute timestamp, -tt -- with usecs\n\
--T -- print time spent in each syscall\n\
--v -- verbose mode: print unabbreviated argv, stat, termios, etc. args\n\
--x -- print non-ascii strings in hex, -xx -- print all strings in hex\n\
--y -- print paths associated with file descriptor arguments\n\
--yy -- print ip:port pairs associated with socket file descriptors\n\
--h -- print help message, -V -- print version\n\
--a column -- alignment COLUMN for printing syscall results (default %d)\n\
--b execve -- detach on this syscall\n\
--e expr -- a qualifying expression: option=[!]all or option=[!]val1[,val2]...\n\
- options: trace, abbrev, verbose, raw, signal, read, write\n\
--I interruptible --\n\
- 1: no signals are blocked\n\
- 2: fatal signals are blocked while decoding syscall (default)\n\
- 3: fatal signals are always blocked (default if '-o FILE PROG')\n\
- 4: fatal signals and SIGTSTP (^Z) are always blocked\n\
- (useful to make 'strace -o FILE PROG' not stop on ^Z)\n\
--o file -- send trace output to FILE instead of stderr\n\
--O overhead -- set overhead for tracing syscalls to OVERHEAD usecs\n\
--p pid -- trace process with process id PID, may be repeated\n\
--s strsize -- limit length of print strings to STRSIZE chars (default %d)\n\
--S sortby -- sort syscall counts by: time, calls, name, nothing (default %s)\n\
--u username -- run command as username handling setuid and/or setgid\n\
--E var=val -- put var=val in the environment for command\n\
--E var -- remove var from the environment for command\n\
--P path -- trace accesses to path\n\
+\n\
+Output format:\n\
+ -a column alignment COLUMN for printing syscall results (default %d)\n\
+ -i print instruction pointer at time of syscall\n\
+ -o file send trace output to FILE instead of stderr\n\
+ -q suppress messages about attaching, detaching, etc.\n\
+ -r print relative timestamp\n\
+ -s strsize limit length of print strings to STRSIZE chars (default %d)\n\
+ -t print absolute timestamp\n\
+ -tt print absolute timestamp with usecs\n\
+ -T print time spent in each syscall\n\
+ -x print non-ascii strings in hex\n\
+ -xx print all strings in hex\n\
+ -y print paths associated with file descriptor arguments\n\
+ -yy print ip:port pairs associated with socket file descriptors\n\
+\n\
+Statistics:\n\
+ -c count time, calls, and errors for each syscall and report summary\n\
+ -C like -c but also print regular output\n\
+ -O overhead set overhead for tracing syscalls to OVERHEAD usecs\n\
+ -S sortby sort syscall counts by: time, calls, name, nothing (default %s)\n\
+ -w summarise syscall latency (default is system time)\n\
+\n\
+Filtering:\n\
+ -e expr a qualifying expression: option=[!]all or option=[!]val1[,val2]...\n\
+ options: trace, abbrev, verbose, raw, signal, read, write\n\
+ -P path trace accesses to path\n\
+\n\
+Tracing:\n\
+ -b execve detach on execve syscall\n\
+ -D run tracer process as a detached grandchild, not as parent\n\
+ -f follow forks\n\
+ -ff follow forks with output into separate files\n\
+ -I interruptible\n\
+ 1: no signals are blocked\n\
+ 2: fatal signals are blocked while decoding syscall (default)\n\
+ 3: fatal signals are always blocked (default if '-o FILE PROG')\n\
+ 4: fatal signals and SIGTSTP (^Z) are always blocked\n\
+ (useful to make 'strace -o FILE PROG' not stop on ^Z)\n\
+\n\
+Startup:\n\
+ -E var remove var from the environment for command\n\
+ -E var=val put var=val in the environment for command\n\
+ -p pid trace process with process id PID, may be repeated\n\
+ -u username run command as username handling setuid and/or setgid\n\
+\n\
+Miscellaneous:\n\
+ -d enable debug output to stderr\n\
+ -v verbose mode: print unabbreviated argv, stat, termios, etc. args\n\
+ -h print help message\n\
+ -V print version\n\
"
#ifdef USE_LIBUNWIND
-"-k obtain stack trace between each syscall (experimental)\n\
+" -k obtain stack trace between each syscall (experimental)\n\
"
#endif
/* ancient, no one should use it
-z -- print only succeeding syscalls\n\
*/
, DEFAULT_ACOLUMN, DEFAULT_STRLEN, DEFAULT_SORTBY);
- exit(exitval);
+ exit(0);
}
-static void die(void) __attribute__ ((noreturn));
-static void die(void)
+static void ATTRIBUTE_NORETURN
+die(void)
{
if (strace_tracer_pid == getpid()) {
cflag = 0;
die();
}
+void error_msg_and_help(const char *fmt, ...)
+{
+ if (fmt != NULL) {
+ va_list p;
+ va_start(p, fmt);
+ verror_msg(0, fmt, p);
+ }
+ fprintf(stderr, "Try '%s -h' for more information.\n", progname);
+ die();
+}
+
void perror_msg(const char *fmt, ...)
{
va_list p;
die();
}
-void die_out_of_memory(void)
-{
- static bool recursed = 0;
- if (recursed)
- exit(1);
- recursed = 1;
- error_msg_and_die("Out of memory");
-}
-
static void
error_opt_arg(int opt, const char *arg)
{
- error_msg_and_die("Invalid -%c argument: '%s'", opt, arg);
+ error_msg_and_help("invalid -%c argument: '%s'", opt, arg);
}
#if USE_SEIZE
So tcbtab is a table of pointers. Since we never
free the TCBs, we allocate a single chunk of many. */
unsigned int i = tcbtabsize;
- struct tcb *newtcbs = calloc(tcbtabsize, sizeof(newtcbs[0]));
- struct tcb **newtab = realloc(tcbtab, tcbtabsize * 2 * sizeof(tcbtab[0]));
- if (!newtab || !newtcbs)
- die_out_of_memory();
+ struct tcb *newtcbs = xcalloc(tcbtabsize, sizeof(newtcbs[0]));
+ struct tcb **newtab = xreallocarray(tcbtab, tcbtabsize * 2,
+ sizeof(tcbtab[0]));
tcbtabsize *= 2;
tcbtab = newtab;
while (i < tcbtabsize)
nprocs++;
if (debug_flag)
- fprintf(stderr, "new tcb for pid %d, active tcbs:%d\n", tcp->pid, nprocs);
+ error_msg("new tcb for pid %d, active tcbs:%d",
+ tcp->pid, nprocs);
return tcp;
}
}
nprocs--;
if (debug_flag)
- fprintf(stderr, "dropped tcb for pid %d, %d remain\n", tcp->pid, nprocs);
+ error_msg("dropped tcb for pid %d, %d remain",
+ tcp->pid, nprocs);
if (tcp->outf) {
if (followfork >= 2) {
}
sig = WSTOPSIG(status);
if (debug_flag)
- fprintf(stderr, "detach wait: event:%d sig:%d\n",
- (unsigned)status >> 16, sig);
+ error_msg("detach wait: event:%d sig:%d",
+ (unsigned)status >> 16, sig);
if (use_seize) {
unsigned event = (unsigned)status >> 16;
if (event == PTRACE_EVENT_STOP /*&& sig == SIGTRAP*/) {
drop:
if (!qflag && (tcp->flags & TCB_ATTACHED))
- fprintf(stderr, "Process %u detached\n", tcp->pid);
+ error_msg("Process %u detached", tcp->pid);
droptcb(tcp);
}
if (ptrace_attach_or_seize(tid) < 0) {
++nerr;
if (debug_flag)
- fprintf(stderr, "attach to pid %d failed\n", tid);
+ error_msg("attach to pid %d failed", tid);
continue;
}
if (debug_flag)
- fprintf(stderr, "attach to pid %d succeeded\n", tid);
+ error_msg("attach to pid %d succeeded", tid);
cur_tcp = tcp;
if (tid != tcp->pid)
cur_tcp = alloctcb(tid);
continue;
}
if (!qflag) {
- fprintf(stderr, ntid > 1
-? "Process %u attached with %u threads\n"
-: "Process %u attached\n",
- tcp->pid, ntid);
+ if (ntid > 1)
+ error_msg("Process %u attached"
+ " with %u threads",
+ tcp->pid, ntid);
+ else
+ error_msg("Process %u attached",
+ tcp->pid);
}
if (!(tcp->flags & TCB_ATTACHED)) {
/* -p PID, we failed to attach to PID itself
tcp->flags |= TCB_ATTACHED | TCB_STARTUP | post_attach_sigstop;
newoutf(tcp);
if (debug_flag)
- fprintf(stderr, "attach to pid %d (main) succeeded\n", tcp->pid);
+ error_msg("attach to pid %d (main) succeeded", tcp->pid);
if (daemonized_tracer) {
/*
}
if (!qflag)
- fprintf(stderr,
- "Process %u attached\n",
- tcp->pid);
+ error_msg("Process %u attached", tcp->pid);
} /* for each tcbtab[] */
ret:
char *pathname;
};
static struct exec_params params_for_tracee;
-static void __attribute__ ((noinline, noreturn))
+
+static void ATTRIBUTE_NOINLINE ATTRIBUTE_NORETURN
exec_or_die(void)
{
struct exec_params *params = ¶ms_for_tracee;
* On NOMMU, can be safely freed only after execve in tracee.
* It's hard to know when that happens, so we just leak it.
*/
- params_for_tracee.pathname = NOMMU_SYSTEM ? strdup(pathname) : pathname;
+ params_for_tracee.pathname = NOMMU_SYSTEM ? xstrdup(pathname) : pathname;
#if defined HAVE_PRCTL && defined PR_SET_PTRACER && defined PR_SET_PTRACER_ANY
if (daemonized_tracer)
if (ptrace(PTRACE_SEIZE, pid, 0, 0) == 0) {
post_attach_sigstop = 0; /* this sets use_seize to 1 */
} else if (debug_flag) {
- fprintf(stderr, "PTRACE_SEIZE doesn't work\n");
+ error_msg("PTRACE_SEIZE doesn't work");
}
kill(pid, SIGKILL);
* Don't want main() to inline us and defeat the reason
* we have a separate function.
*/
-static void __attribute__ ((noinline))
+static void ATTRIBUTE_NOINLINE
init(int argc, char *argv[])
{
struct tcb *tcp;
/* Allocate the initial tcbtab. */
tcbtabsize = argc; /* Surely enough for all -p args. */
- tcbtab = calloc(tcbtabsize, sizeof(tcbtab[0]));
- if (!tcbtab)
- die_out_of_memory();
- tcp = calloc(tcbtabsize, sizeof(*tcp));
- if (!tcp)
- die_out_of_memory();
+ tcbtab = xcalloc(tcbtabsize, sizeof(tcbtab[0]));
+ tcp = xcalloc(tcbtabsize, sizeof(*tcp));
for (tcbi = 0; tcbi < tcbtabsize; tcbi++)
tcbtab[tcbi] = tcp++;
break;
case 'c':
if (cflag == CFLAG_BOTH) {
- error_msg_and_die("-c and -C are mutually exclusive");
+ error_msg_and_help("-c and -C are mutually exclusive");
}
cflag = CFLAG_ONLY_STATS;
break;
case 'C':
if (cflag == CFLAG_ONLY_STATS) {
- error_msg_and_die("-c and -C are mutually exclusive");
+ error_msg_and_help("-c and -C are mutually exclusive");
}
cflag = CFLAG_BOTH;
break;
followfork++;
break;
case 'h':
- usage(stdout, 0);
+ usage();
break;
case 'i':
iflag = 1;
qualify(optarg);
break;
case 'o':
- outfname = strdup(optarg);
+ outfname = xstrdup(optarg);
break;
case 'O':
i = string_to_uint(optarg);
set_sortby(optarg);
break;
case 'u':
- username = strdup(optarg);
+ username = xstrdup(optarg);
break;
#ifdef USE_LIBUNWIND
case 'k':
error_opt_arg(c, optarg);
break;
default:
- usage(stderr, 1);
+ error_msg_and_help(NULL);
break;
}
}
argv += optind;
/* argc -= optind; - no need, argc is not used below */
- acolumn_spaces = malloc(acolumn + 1);
- if (!acolumn_spaces)
- die_out_of_memory();
+ acolumn_spaces = xmalloc(acolumn + 1);
memset(acolumn_spaces, ' ', acolumn);
acolumn_spaces[acolumn] = '\0';
/* Must have PROG [ARGS], or -p PID. Not both. */
- if (!argv[0] == !nprocs)
- usage(stderr, 1);
+ if (!argv[0] == !nprocs) {
+ error_msg_and_help("must have PROG [ARGS] or -p PID");
+ }
if (nprocs != 0 && daemonized_tracer) {
- error_msg_and_die("-D and -p are mutually exclusive");
+ error_msg_and_help("-D and -p are mutually exclusive");
}
if (!followfork)
followfork = optF;
if (followfork >= 2 && cflag) {
- error_msg_and_die("(-c or -C) and -ff are mutually exclusive");
+ error_msg_and_help("(-c or -C) and -ff are mutually exclusive");
}
if (count_wallclock && !cflag) {
- error_msg_and_die("-w must be given with (-c or -C)");
+ error_msg_and_help("-w must be given with (-c or -C)");
}
if (cflag == CFLAG_ONLY_STATS) {
PTRACE_O_TRACEFORK |
PTRACE_O_TRACEVFORK;
if (debug_flag)
- fprintf(stderr, "ptrace_setoptions = %#x\n", ptrace_setoptions);
+ error_msg("ptrace_setoptions = %#x", ptrace_setoptions);
test_ptrace_seize();
/* Check if they want to redirect the output. */
* when using popen, so prohibit it.
*/
if (followfork >= 2)
- error_msg_and_die("Piping the output and -ff are mutually exclusive");
+ error_msg_and_help("piping the output and -ff are mutually exclusive");
shared_log = strace_popen(outfname + 1);
}
else if (followfork < 2)
}
if (!outfname || outfname[0] == '|' || outfname[0] == '!') {
- char *buf = malloc(BUFSIZ);
- if (!buf)
- die_out_of_memory();
+ char *buf = xmalloc(BUFSIZ);
setvbuf(shared_log, buf, _IOLBF, BUFSIZ);
}
if (outfname && argv[0]) {
if (!opt_intr)
opt_intr = INTR_NEVER;
- qflag = 1;
+ if (!qflag)
+ qflag = 1;
}
if (!opt_intr)
opt_intr = INTR_WHILE_WAIT;
if (!tcp->pid)
continue;
if (debug_flag)
- fprintf(stderr,
- "cleanup: looking at pid %u\n", tcp->pid);
+ error_msg("cleanup: looking at pid %u", tcp->pid);
if (tcp->pid == strace_child) {
kill(tcp->pid, SIGCONT);
kill(tcp->pid, fatal_sig);
e = "STOP";
sprintf(evbuf, ",EVENT_%s (%u)", e, event);
}
- fprintf(stderr, " [wait(0x%06x) = %u] %s%s\n", status, pid, buf, evbuf);
+ error_msg("[wait(0x%06x) = %u] %s%s", status, pid, buf, evbuf);
}
static struct tcb *
tcp->flags |= TCB_ATTACHED | TCB_STARTUP | post_attach_sigstop;
newoutf(tcp);
if (!qflag)
- fprintf(stderr, "Process %d attached\n", pid);
+ error_msg("Process %d attached", pid);
return tcp;
} else {
/* This can happen if a clone call used
startup_tcb(struct tcb *tcp)
{
if (debug_flag)
- fprintf(stderr, "pid %d has TCB_STARTUP, initializing it\n",
- tcp->pid);
+ error_msg("pid %d has TCB_STARTUP, initializing it", tcp->pid);
tcp->flags &= ~TCB_STARTUP;
if (!use_seize) {
if (debug_flag)
- fprintf(stderr, "setting opts 0x%x on pid %d\n",
- ptrace_setoptions, tcp->pid);
+ error_msg("setting opts 0x%x on pid %d",
+ ptrace_setoptions, tcp->pid);
if (ptrace(PTRACE_SETOPTIONS, tcp->pid, NULL, ptrace_setoptions) < 0) {
if (errno != ESRCH) {
/* Should never happen, really */
if (interrupted)
return false;
- if (popen_pid != 0 && nprocs == 0)
- return false;
+ /*
+ * Used to exit simply when nprocs hits zero, but in this testcase:
+ * int main() { _exit(!!fork()); }
+ * under strace -f, parent sometimes (rarely) manages
+ * to exit before we see the first stop of the child,
+ * and we are losing track of it:
+ * 19923 clone(...) = 19924
+ * 19923 exit_group(1) = ?
+ * 19923 +++ exited with 1 +++
+ * Exiting only when wait() returns ECHILD works better.
+ */
+ if (popen_pid != 0) {
+ /* However, if -o|logger is in use, we can't do that.
+ * Can work around that by double-forking the logger,
+ * but that loses the ability to wait for its completion
+ * on exit. Oh well...
+ */
+ if (nprocs == 0)
+ return false;
+ }
if (interactive)
sigprocmask(SIG_SETMASK, &empty_set, NULL);
*/
if (sig == SIGSTOP && (tcp->flags & TCB_IGNORE_ONE_SIGSTOP)) {
if (debug_flag)
- fprintf(stderr, "ignored SIGSTOP on pid %d\n", tcp->pid);
+ error_msg("ignored SIGSTOP on pid %d", tcp->pid);
tcp->flags &= ~TCB_IGNORE_ONE_SIGSTOP;
goto restart_tracee_with_sig_0;
}
if (sig != syscall_trap_sig) {
- siginfo_t si;
+ siginfo_t si = {};
/*
* True if tracee is stopped by signal
{
init(argc, argv);
- /*
- * Run main tracing loop.
- *
- * Used to be "while (nprocs != 0)", but in this testcase:
- * int main() { _exit(!!fork()); }
- * under strace -f, parent sometimes (rarely) manages
- * to exit before we see the first stop of the child,
- * and we are losing track of it:
- * 19923 clone(...) = 19924
- * 19923 exit_group(1) = ?
- * 19923 +++ exited with 1 +++
- * Waiting for ECHILD works better.
- * (However, if -o|logger is in use, we can't do that.
- * Can work around that by double-forking the logger,
- * but that loses the ability to wait for its completion on exit.
- * Oh well...)
- */
while (trace())
;