Attachment 160505 Details for Bug 247907 – patch does work

[patch] patch does work

strace-3thread.patch (text/plain), 7.35 KB, created by Jan Kratochvil on 2007-08-02 08:50:04 UTC

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Creator: Jan Kratochvil

Created: 2007-08-02 08:50:04 UTC

Size: 7.35 KB

patch

obsolete

>2007-08-02  Jan Kratochvil  <jan.kratochvil@redhat.com>
>
>	* strace.c (detach): Moved the resume notification code to ...
>	(resume_from_tcp): ... a new function here.
>	(handle_group_exit): No longer detach also the thread group leader.
>	(trace): Fixed panic on exit of the TCB_GROUP_EXITING leader itself.
>
>	* test/leaderkill.c (start): Renamed to ...
>	(start0): ... here.
>	(start1): New function.
>	(main): Created a new spare thread.
>
>--- strace.c	11 Jul 2007 08:35:11 -0000	1.81
>+++ strace.c	2 Aug 2007 08:38:39 -0000
>@@ -1337,6 +1337,71 @@ struct tcb *tcp;
> 	return 0;
> }
> 
>+static int
>+resume_from_tcp (struct tcb *tcp)
>+{
>+	int error = 0;
>+	int resumed = 0;
>+
>+	/* XXX This won't always be quite right (but it never was).
>+	   A waiter with argument 0 or < -1 is waiting for any pid in
>+	   a particular pgrp, which this child might or might not be
>+	   in.  The waiter will only wake up if it's argument is -1
>+	   or if it's waiting for tcp->pid's pgrp.  It makes a
>+	   difference to wake up a waiter when there might be more
>+	   traced children, because it could get a false ECHILD
>+	   error.  OTOH, if this was the last child in the pgrp, then
>+	   it ought to wake up and get ECHILD.  We would have to
>+	   search the system for all pid's in the pgrp to be sure.
>+
>+	     && (t->waitpid == -1 ||
>+		 (t->waitpid == 0 && getpgid (tcp->pid) == getpgid (t->pid))
>+		 || (t->waitpid < 0 && t->waitpid == -getpid (t->pid)))
>+	*/
>+
>+	if (tcp->parent &&
>+	    (tcp->parent->flags & TCB_SUSPENDED) &&
>+	    (tcp->parent->waitpid <= 0 || tcp->parent->waitpid == tcp->pid)) {
>+ 		error = resume(tcp->parent);
>+		++resumed;
>+	}
>+#ifdef TCB_CLONE_THREAD
>+	if (tcp->parent && tcp->parent->nclone_waiting > 0) {
>+		/* Some other threads of our parent are waiting too.  */
>+		unsigned int i;
>+
>+		/* Resume all the threads that were waiting for this PID.  */
>+		for (i = 0; i < tcbtabsize; i++) {
>+			struct tcb *t = tcbtab[i];
>+			if (t->parent == tcp->parent && t != tcp
>+			    && ((t->flags & (TCB_CLONE_THREAD|TCB_SUSPENDED))
>+				== (TCB_CLONE_THREAD|TCB_SUSPENDED))
>+			    && t->waitpid == tcp->pid) {
>+				error |= resume (t);
>+				++resumed;
>+			}
>+		}
>+		if (resumed == 0)
>+			/* Noone was waiting for this PID in particular,
>+			   so now we might need to resume some wildcarders.  */
>+			for (i = 0; i < tcbtabsize; i++) {
>+				struct tcb *t = tcbtab[i];
>+				if (t->parent == tcp->parent && t != tcp
>+				    && ((t->flags
>+					 & (TCB_CLONE_THREAD|TCB_SUSPENDED))
>+					== (TCB_CLONE_THREAD|TCB_SUSPENDED))
>+				    && t->waitpid <= 0
>+					) {
>+					error |= resume (t);
>+					break;
>+				}
>+			}
>+	}
>+
>+	return error;
>+}
>+#endif
>+
> #endif /* !USE_PROCFS */
> 
> /* detach traced process; continue with sig
>@@ -1351,7 +1416,7 @@ int sig;
> {
> 	int error = 0;
> #ifdef LINUX
>-	int status, resumed, catch_sigstop;
>+	int status, catch_sigstop;
> 	struct tcb *zombie = NULL;
> 
> 	/* If the group leader is lingering only because of this other
>@@ -1465,66 +1530,9 @@ int sig;
> #endif /* SUNOS4 */
> 
> #ifndef USE_PROCFS
>-	resumed = 0;
>-
>-	/* XXX This won't always be quite right (but it never was).
>-	   A waiter with argument 0 or < -1 is waiting for any pid in
>-	   a particular pgrp, which this child might or might not be
>-	   in.  The waiter will only wake up if it's argument is -1
>-	   or if it's waiting for tcp->pid's pgrp.  It makes a
>-	   difference to wake up a waiter when there might be more
>-	   traced children, because it could get a false ECHILD
>-	   error.  OTOH, if this was the last child in the pgrp, then
>-	   it ought to wake up and get ECHILD.  We would have to
>-	   search the system for all pid's in the pgrp to be sure.
>-
>-	     && (t->waitpid == -1 ||
>-		 (t->waitpid == 0 && getpgid (tcp->pid) == getpgid (t->pid))
>-		 || (t->waitpid < 0 && t->waitpid == -getpid (t->pid)))
>-	*/
>-
>-	if (tcp->parent &&
>-	    (tcp->parent->flags & TCB_SUSPENDED) &&
>-	    (tcp->parent->waitpid <= 0 || tcp->parent->waitpid == tcp->pid)) {
>- 		error = resume(tcp->parent);
>-		++resumed;
>-	}
>-#ifdef TCB_CLONE_THREAD
>-	if (tcp->parent && tcp->parent->nclone_waiting > 0) {
>-		/* Some other threads of our parent are waiting too.  */
>-		unsigned int i;
>-
>-		/* Resume all the threads that were waiting for this PID.  */
>-		for (i = 0; i < tcbtabsize; i++) {
>-			struct tcb *t = tcbtab[i];
>-			if (t->parent == tcp->parent && t != tcp
>-			    && ((t->flags & (TCB_CLONE_THREAD|TCB_SUSPENDED))
>-				== (TCB_CLONE_THREAD|TCB_SUSPENDED))
>-			    && t->waitpid == tcp->pid) {
>-				error |= resume (t);
>-				++resumed;
>-			}
>-		}
>-		if (resumed == 0)
>-			/* Noone was waiting for this PID in particular,
>-			   so now we might need to resume some wildcarders.  */
>-			for (i = 0; i < tcbtabsize; i++) {
>-				struct tcb *t = tcbtab[i];
>-				if (t->parent == tcp->parent && t != tcp
>-				    && ((t->flags
>-					 & (TCB_CLONE_THREAD|TCB_SUSPENDED))
>-					== (TCB_CLONE_THREAD|TCB_SUSPENDED))
>-				    && t->waitpid <= 0
>-					) {
>-					error |= resume (t);
>-					break;
>-				}
>-			}
>-	}
>+	error |= resume_from_tcp (tcp);
> #endif
> 
>-#endif /* !USE_PROCFS */
>-
> 	if (!qflag)
> 		fprintf(stderr, "Process %u detached\n", tcp->pid);
> 
>@@ -2109,6 +2117,9 @@ handle_group_exit(struct tcb *tcp, int s
> 				"PANIC: handle_group_exit: %d leader %d\n",
> 				tcp->pid, leader ? leader->pid : -1);
> 		/* TCP no longer exists therefore you must not detach () it.  */
>+#ifndef USE_PROCFS
>+		resume_from_tcp (tcp);
>+#endif
> 		droptcb(tcp);	/* Already died.  */
> 	}
> 	else {
>@@ -2116,21 +2127,8 @@ handle_group_exit(struct tcb *tcp, int s
> 		tcp->flags |= TCB_EXITING | TCB_GROUP_EXITING;
> 		if (tcp->flags & TCB_ATTACHED) {
> 			detach(tcp, sig);
>-		  	if (leader != NULL && leader != tcp) {
>-				if ((leader->flags & TCB_ATTACHED) &&
>-				    !(leader->flags & TCB_EXITING)) {
>-					/* We need to detach the leader so
>-					   that the process death will be
>-					   reported to its real parent.  */
>-					if (debug)
>-						fprintf(stderr,
>-							" [%d exit %d detaches %d]\n",
>-							tcp->pid, sig, leader->pid);
>-					detach(leader, sig);
>-				}
>-				else
>-					leader->flags |= TCB_GROUP_EXITING;
>-			}
>+		  	if (leader != NULL && leader != tcp)
>+				leader->flags |= TCB_GROUP_EXITING;
> 		}
> 		else if (ptrace(PTRACE_CONT, tcp->pid, (char *) 1, sig) < 0) {
> 			perror("strace: ptrace(PTRACE_CONT, ...)");
>@@ -2318,6 +2316,7 @@ Process %d attached (waiting for parent)
> #ifdef TCB_GROUP_EXITING
> 			    && !(tcp->parent && (tcp->parent->flags &
> 						 TCB_GROUP_EXITING))
>+			    && !(tcp->flags & TCB_GROUP_EXITING)
> #endif
> 				)
> 				fprintf(stderr,
>--- test/leaderkill.c	5 Jul 2007 18:43:18 -0000	1.1
>+++ test/leaderkill.c	2 Aug 2007 08:38:40 -0000
>@@ -13,15 +13,23 @@
> #include <stdio.h>
> #include <sys/wait.h>
> 
>-static void *start (void *arg)
>+static void *start0 (void *arg)
> {
>   sleep (1);
> 
>   exit (42);
> }
> 
>+static void *start1 (void *arg)
>+{
>+  pause ();
>+  /* NOTREACHED */
>+  assert (0);
>+}
>+
> int main (void)
> {
>+  pthread_t thread0;
>   pthread_t thread1;
>   int i;
>   pid_t child, got_pid;
>@@ -35,16 +43,13 @@ int main (void)
>       case -1:
> 	abort ();
>       case 0:
>-	i = pthread_create (&thread1, NULL, start, NULL);
>+	i = pthread_create (&thread0, NULL, start0, NULL);
>+	assert (i == 0);
>+	i = pthread_create (&thread1, NULL, start1, NULL);
> 	assert (i == 0);
>-/* Two possible testcases; the second one passed even in the older versions.  */
>-#if 1
> 	pause ();
>-#else
>-	pthread_exit (NULL);
>-#endif
> 	/* NOTREACHED */
>-	abort ();
>+	assert (0);
> 	break;
>       default:
> 	got_pid = waitpid (child, &status, 0);

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Attachments on bug 247907: 159013 | 159827 | 160505