In -f mode, do not assume that new pid is stopped - handle exits too

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>

diff --git a/strace.c b/strace.c
index 4fb1b46e1d48c03bda5413fb5016d89fea4c10f2..743e324e3a4edc995c3aa7786b804ff9e21fcd41 100644 (file)
--- a/strace.c
+++ b/strace.c
@@ -1993,7 +1993,7 @@ trace(void)
                }
 
                if (pid == popen_pid) {
-                       if (WIFEXITED(status) || WIFSIGNALED(status))
+                       if (!WIFSTOPPED(status))
                                popen_pid = 0;
                        continue;
                }
@@ -2017,6 +2017,7 @@ trace(void)
                        if (WIFSTOPPED(status))
                                sprintf(buf, "WIFSTOPPED,sig=%s", signame(WSTOPSIG(status)));
 #ifdef WIFCONTINUED
+                       /* Should never be seen */
                        if (WIFCONTINUED(status))
                                strcpy(buf, "WIFCONTINUED");
 #endif
@@ -2045,7 +2046,16 @@ trace(void)
                tcp = pid2tcb(pid);
 
                if (!tcp) {
+                       if (!WIFSTOPPED(status)) {
+                               /* This can happen if we inherited
+                                * an unknown child. Example:
+                                * (sleep 1 & exec strace sleep 2)
+                                */
+                               error_msg("Exit of unknown pid %u seen", pid);
+                               continue;
+                       }
                        if (followfork) {
+                               /* We assume it's a fork/vfork/clone child */
                                tcp = alloctcb(pid);
                                tcp->flags |= TCB_ATTACHED | TCB_STARTUP | post_attach_sigstop;
                                newoutf(tcp);
@@ -2054,16 +2064,10 @@ trace(void)
                                                pid);
                        } else {
                                /* This can happen if a clone call used
-                                * CLONE_PTRACE itself, or if we inherited
-                                * an unknown child. Example:
-                                * (sleep 1 & exec strace sleep 2)
+                                * CLONE_PTRACE itself.
                                 */
-                               if (WIFSTOPPED(status)) {
-                                       ptrace(PTRACE_CONT, pid, (char *) 0, 0);
-                                       error_msg("Stop of unknown pid %u seen, PTRACE_CONTed it", pid);
-                               } else {
-                                       error_msg("Exit of unknown pid %u seen", pid);
-                               }
+                               ptrace(PTRACE_CONT, pid, (char *) 0, 0);
+                               error_msg("Stop of unknown pid %u seen, PTRACE_CONTed it", pid);
                                continue;
                        }
                }