From: Roland McGrath <roland@redhat.com>
Date: Wed, 15 Sep 2010 01:59:20 +0000 (-0700)
Subject: Clean up pid2tcb usage
X-Git-Tag: v4.6~88
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=54e931fb858410644f61885b4b36fc20320e1fc6;p=strace

Clean up pid2tcb usage

* strace.c (pid2tcb): Always match pid.  Fail for argument <= 0.
[USE_PROCFS] (first_used_tcb): New function.
[USE_PROCFS] (trace): Use that instead of pid2tcb(0).
---

diff --git a/strace.c b/strace.c
index 3cb3758c..497b8d15 100644
--- a/strace.c
+++ b/strace.c
@@ -1337,24 +1337,37 @@ proc_open(struct tcb *tcp, int attaching)
 #endif /* USE_PROCFS */
 
 struct tcb *
-pid2tcb(pid)
-int pid;
+pid2tcb(int pid)
 {
 	int i;
-	struct tcb *tcp;
+
+	if (pid <= 0)
+		return NULL;
 
 	for (i = 0; i < tcbtabsize; i++) {
-		tcp = tcbtab[i];
-		if (pid && tcp->pid != pid)
-			continue;
-		if (tcp->flags & TCB_INUSE)
+		struct tcb *tcp = tcbtab[i];
+		if (tcp->pid == pid && (tcp->flags & TCB_INUSE))
 			return tcp;
 	}
+
 	return NULL;
 }
 
 #ifdef USE_PROCFS
 
+static struct tcb *
+first_used_tcb(void)
+{
+	int i;
+	struct tcb *tcp;
+	for (i = 0; i < tcbtabsize; i++) {
+		tcp = tcbtab[i];
+		if (tcp->flags & TCB_INUSE)
+			return tcp;
+	}
+	return NULL;
+}
+
 static struct tcb *
 pfd2tcb(pfd)
 int pfd;
@@ -1992,7 +2005,7 @@ trace()
 #ifndef HAVE_POLLABLE_PROCFS
 			if (proc_poll_pipe[0] == -1) {
 #endif
-				tcp = pid2tcb(0);
+				tcp = first_used_tcb();
 				if (!tcp)
 					continue;
 				pfd = tcp->pfd;