Log the process id in the debug file output. Since we don't want

to keep calling getpid(), stash the value at init time and when we
fork().

common/sudo_debug.c

@@ -114,6 +114,8 @@ const char *const sudo_debug_subsystems[] = {
 static int sudo_debug_settings[NUM_SUBSYSTEMS];
 static int sudo_debug_fd = -1;
 static int sudo_debug_mode;
+static char sudo_debug_pidstr[(((sizeof(int) * 8) + 2) / 3) + 3];
+static size_t sudo_debug_pidlen;
 
 extern sudo_conv_t sudo_conv;
 
@@ -174,9 +176,27 @@ int sudo_debug_init(const char *debugfile, const char *settings)
     }
     efree(buf);
 
+    (void)snprintf(sudo_debug_pidstr, sizeof(sudo_debug_pidstr), "[%d] ",
+	(int)getpid());
+    sudo_debug_pidlen = strlen(sudo_debug_pidstr);
+
     return 1;
 }
 
+pid_t
+sudo_debug_fork(void)
+{
+    pid_t pid;
+
+    if ((pid = fork()) == 0) {
+	(void)snprintf(sudo_debug_pidstr, sizeof(sudo_debug_pidstr), "[%d] ",
+	    (int)getpid());
+	sudo_debug_pidlen = strlen(sudo_debug_pidstr);
+    }
+
+    return pid;
+}
+
 void
 sudo_debug_enter(const char *func, const char *file, int line,
     int subsys)
@@ -298,11 +318,11 @@ sudo_debug_write_file(const char *func, const char *file, int lineno,
     int iovcnt = 4;
     bool need_newline = false;
 
-    /* Prepend program name with trailing space. */
+    /* Prepend program name and pid with a trailing space. */
     iov[1].iov_base = (char *)getprogname();
     iov[1].iov_len = strlen(iov[1].iov_base);
-    iov[2].iov_base = " ";
+    iov[2].iov_base = sudo_debug_pidstr;
-    iov[2].iov_len = 1;
+    iov[2].iov_len = sudo_debug_pidlen;
 
     /* Add string along with newline if it doesn't have one. */
     iov[3].iov_base = (char *)str;

include/sudo_debug.h

@@ -203,5 +203,6 @@ int sudo_debug_init(const char *debugfile, const char *settings);
 void sudo_debug_printf2(const char *func, const char *file, int line, int level, const char *format, ...) __printflike(5, 6);
 void sudo_debug_write(const char *str, int len, int errno_val);
 void sudo_debug_write2(const char *func, const char *file, int line, const char *str, int len, int errno_val);
+pid_t sudo_debug_fork(void);
 
 #endif /* _SUDO_DEBUG_H */

plugins/sudoers/logging.c

@@ -441,7 +441,7 @@ send_mail(const char *fmt, ...)
 	debug_return;
 
     /* Fork and return, child will daemonize. */
-    switch (pid = fork()) {
+    switch (pid = sudo_debug_fork()) {
 	case -1:
 	    /* Error. */
 	    error(1, _("unable to fork"));
@@ -510,7 +510,7 @@ send_mail(const char *fmt, ...)
 	_exit(1);
     }
 
-    switch (pid = fork()) {
+    switch (pid = sudo_debug_fork()) {
 	case -1:
 	    /* Error. */
 	    mysyslog(LOG_ERR, _("unable to fork: %m"));

plugins/sudoers/visudo.c

@@ -751,7 +751,7 @@ run_command(char *path, char **argv)
     pid_t pid, rv;
     debug_decl(run_command, SUDO_DEBUG_UTIL)
 
-    switch (pid = fork()) {
+    switch (pid = sudo_debug_fork()) {
 	case -1:
 	    error(1, _("unable to execute %s"), path);
 	    break;	/* NOTREACHED */

src/exec.c

@@ -99,7 +99,7 @@ static int fork_cmnd(struct command_details *details, int sv[2])
     sa.sa_handler = handler;
     sigaction(SIGCONT, &sa, NULL);
 
-    child = fork();
+    child = sudo_debug_fork();
     switch (child) {
     case -1:
 	error(1, _("unable to fork"));
@@ -214,7 +214,7 @@ sudo_execute(struct command_details *details, struct command_status *cstat)
 
     /* If running in background mode, fork and exit. */
     if (ISSET(details->flags, CD_BACKGROUND)) {
-	switch (fork()) {
+	switch (sudo_debug_fork()) {
 	    case -1:
 		cstat->type = CMD_ERRNO;
 		cstat->val = errno;

src/exec_pty.c

@@ -618,7 +618,7 @@ fork_pty(struct command_details *details, int sv[], int *maxfd)
 	}
     }
 
-    child = fork();
+    child = sudo_debug_fork();
     switch (child) {
     case -1:
 	error(1, _("unable to fork"));
@@ -953,7 +953,7 @@ exec_monitor(struct command_details *details, int backchannel)
     /* Start command and wait for it to stop or exit */
     if (pipe(errpipe) == -1)
 	error(1, _("unable to create pipe"));
-    child = fork();
+    child = sudo_debug_fork();
     if (child == -1) {
 	warning(_("unable to fork"));
 	goto bad;