On 19/08/09 09:34, Jim Meyering wrote:
There were a few unchecked syscalls in fish.c
> From ba8b8b0684a03b6e6fbb939ed7e1cbf5e1000092 Mon Sep 17 00:00:00 2001
From: Jim Meyering<meyering(a)redhat.com>
Date: Wed, 19 Aug 2009 10:01:07 +0200
Subject: [PATCH libguestfs] guestfish: detect a few more failed syscalls
* fish/fish.c (issue_command): Detect/diagnose more failed syscalls.
---
fish/fish.c | 26 +++++++++++++++++++++-----
1 files changed, 21 insertions(+), 5 deletions(-)
diff --git a/fish/fish.c b/fish/fish.c
index 830617b..e6cd270 100644
--- a/fish/fish.c
+++ b/fish/fish.c
@@ -750,8 +750,14 @@ issue_command (const char *cmd, char *argv[], const char *pipecmd)
if (pipecmd) {
int fd[2];
- fflush (stdout);
- pipe (fd);
+ if (fflush (stdout)); {
Looks like a stray semicolon in there. Also, wouldn't it be better form
to test for test for a return value of EOF?
+ perror ("failed to flush standard output");
+ return -1;
+ }
+ if (pipe (fd)) {
+ perror ("pipe failed");
+ return -1;
+ }
Again, I'd explicitly test for a return value of -1 for consistency.
pid = fork ();
if (pid == -1) {
perror ("fork");
@@ -760,7 +766,10 @@ issue_command (const char *cmd, char *argv[], const char *pipecmd)
if (pid == 0) { /* Child process. */
close (fd[1]);
- dup2 (fd[0], 0);
+ if (dup2 (fd[0], 0)< 0) {
+ perror ("dup2 of stdin failed");
+ _exit (1);
+ }
fd[1] ought to be closed after this call. Not directly relevant to this
patch, but '0' is a magic number. Use STDIN_FILENO from unistd.h.
r = system (pipecmd);
if (r == -1) {
@@ -770,9 +779,16 @@ issue_command (const char *cmd, char *argv[], const char *pipecmd)
_exit (WEXITSTATUS (r));
}
- stdout_saved_fd = dup (1);
+ if ((stdout_saved_fd = dup (1))< 0) {
+ perror ("failed to dup stdout");
+ return -1;
+ }
'1' is a magic number. Use STDOUT_FILENO from unistd.h.
close (fd[0]);
- dup2 (fd[1], 1);
+ if (dup2 (fd[1], 1)) {
+ perror ("failed to dup stdout");
+ close (stdout_saved_fd);
+ return -1;
+ }
Test for return value of -1. '1' is a magic number.
close (fd[1]);
}
--
1.6.4.378.g88f2f
Matt
--
Matthew Booth, RHCA, RHCSS
Red Hat Engineering, Virtualisation Team
M: +44 (0)7977 267231
GPG ID: D33C3490
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