From: Dmitry V. Levin <ldv@altlinux.org>
Date: Mon, 17 Sep 2012 22:40:12 +0000 (+0000)
Subject: Ignore fflush(3) return value
X-Git-Tag: v4.8~214
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=b742d8c1b8001dd2b8784f5a123cc8eb08f679ca;p=strace

Ignore fflush(3) return value

strace used to honor fflush(3) return value in trace_syscall_entering
which resulted to tracees not being PTRACE_SYSCALL'ed which in turn
caused nasty hangups like this one:

$ strace -o'|:' pwd
|:: Broken pipe

There is little strace can do in case of fflush(3) returning EOF, and
hangup is certainly not the best solution for the issue.

* syscall.c (trace_syscall_entering): Ignore fflush(3) return value.
---

diff --git a/syscall.c b/syscall.c
index cda017c5..c4c5e868 100644
--- a/syscall.c
+++ b/syscall.c
@@ -1581,8 +1581,7 @@ trace_syscall_entering(struct tcb *tcp)
 	else
 		res = (*sysent[tcp->scno].sys_func)(tcp);
 
-	if (fflush(tcp->outf) == EOF)
-		return -1;
+	fflush(tcp->outf);
  ret:
 	tcp->flags |= TCB_INSYSCALL;
 	/* Measure the entrance time as late as possible to avoid errors. */