Patchwork [10/14] vl.c: fix warning with _FORTIFY_SOURCE

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Submitter Kirill A. Shutemov
Date Dec. 31, 2009, 1:34 a.m.
Message ID <1262223266-19191-1-git-send-email-kirill@shutemov.name>
Download mbox | patch
Permalink /patch/41955/
State New
Headers show

Comments

Kirill A. Shutemov - Dec. 31, 2009, 1:34 a.m.
CC    i386-softmmu/vl.o
cc1: warnings being treated as errors
/usr/src/RPM/BUILD/qemu-0.11.92/vl.c: In function 'qemu_event_increment':
/usr/src/RPM/BUILD/qemu-0.11.92/vl.c:3404: error: ignoring return value of 'write', declared with attribute warn_unused_result
/usr/src/RPM/BUILD/qemu-0.11.92/vl.c: In function 'main':
/usr/src/RPM/BUILD/qemu-0.11.92/vl.c:5774: error: ignoring return value of 'write', declared with attribute warn_unused_result
/usr/src/RPM/BUILD/qemu-0.11.92/vl.c:6064: error: ignoring return value of 'chdir', declared with attribute warn_unused_result
/usr/src/RPM/BUILD/qemu-0.11.92/vl.c:6083: error: ignoring return value of 'chdir', declared with attribute warn_unused_result
make[1]: *** [vl.o] Error 1

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
---
 vl.c |   23 +++++++++++++++++++----
 1 files changed, 19 insertions(+), 4 deletions(-)
malc - Dec. 31, 2009, 2:05 a.m.
On Thu, 31 Dec 2009, Kirill A. Shutemov wrote:

>   CC    i386-softmmu/vl.o
> cc1: warnings being treated as errors
> /usr/src/RPM/BUILD/qemu-0.11.92/vl.c: In function 'qemu_event_increment':
> /usr/src/RPM/BUILD/qemu-0.11.92/vl.c:3404: error: ignoring return value of 'write', declared with attribute warn_unused_result
> /usr/src/RPM/BUILD/qemu-0.11.92/vl.c: In function 'main':
> /usr/src/RPM/BUILD/qemu-0.11.92/vl.c:5774: error: ignoring return value of 'write', declared with attribute warn_unused_result
> /usr/src/RPM/BUILD/qemu-0.11.92/vl.c:6064: error: ignoring return value of 'chdir', declared with attribute warn_unused_result
> /usr/src/RPM/BUILD/qemu-0.11.92/vl.c:6083: error: ignoring return value of 'chdir', declared with attribute warn_unused_result
> make[1]: *** [vl.o] Error 1
> 
> Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
> ---
>  vl.c |   23 +++++++++++++++++++----
>  1 files changed, 19 insertions(+), 4 deletions(-)
> 
> diff --git a/vl.c b/vl.c
> index e881e45..4527427 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -3390,11 +3390,17 @@ static int io_thread_fd = -1;
>  static void qemu_event_increment(void)
>  {
>      static const char byte = 0;
> +    int ret;
>  
>      if (io_thread_fd == -1)
>          return;
>  
> -    write(io_thread_fd, &byte, sizeof(byte));
> +    ret = write(io_thread_fd, &byte, sizeof(byte));

write returns ssize_t

> +    if (ret < 0 && (errno != EINTR && errno != EAGAIN)) {

Elsewhere in the series you only check for EAGAIN.

> +        fprintf(stderr, "qemu_event_increment: write() filed: %s\n",
> +                strerror(errno));
> +        exit (1);
> +    }
>  }
>  
>  static void qemu_event_read(void *opaque)
> @@ -5778,7 +5784,10 @@ int main(int argc, char **argv, char **envp)
>  #ifndef _WIN32
>          if (daemonize) {
>              uint8_t status = 1;
> -            write(fds[1], &status, 1);
> +            if (write(fds[1], &status, 1) != 1) {
> +                perror("write()");
> +                exit(1);
> +            }
>          } else
>  #endif
>              fprintf(stderr, "Could not acquire pid file: %s\n", strerror(errno));
> @@ -6075,7 +6084,10 @@ int main(int argc, char **argv, char **envp)
>  	if (len != 1)
>  	    exit(1);
>  
> -	chdir("/");
> +	if (chdir("/")) {
> +        perror("chdir()");
> +        exit(1);
> +    }
>  	TFR(fd = qemu_open("/dev/null", O_RDWR));
>  	if (fd == -1)
>  	    exit(1);
> @@ -6094,7 +6106,10 @@ int main(int argc, char **argv, char **envp)
>              fprintf(stderr, "chroot failed\n");
>              exit(1);
>          }
> -        chdir("/");
> +        if (chdir("/")) {
> +            perror("chdir()");
> +            exit(1);
> +        }
>      }
>  
>      if (run_as) {

Here and elsewhere the indentation is off.

Patch

diff --git a/vl.c b/vl.c
index e881e45..4527427 100644
--- a/vl.c
+++ b/vl.c
@@ -3390,11 +3390,17 @@  static int io_thread_fd = -1;
 static void qemu_event_increment(void)
 {
     static const char byte = 0;
+    int ret;
 
     if (io_thread_fd == -1)
         return;
 
-    write(io_thread_fd, &byte, sizeof(byte));
+    ret = write(io_thread_fd, &byte, sizeof(byte));
+    if (ret < 0 && (errno != EINTR && errno != EAGAIN)) {
+        fprintf(stderr, "qemu_event_increment: write() filed: %s\n",
+                strerror(errno));
+        exit (1);
+    }
 }
 
 static void qemu_event_read(void *opaque)
@@ -5778,7 +5784,10 @@  int main(int argc, char **argv, char **envp)
 #ifndef _WIN32
         if (daemonize) {
             uint8_t status = 1;
-            write(fds[1], &status, 1);
+            if (write(fds[1], &status, 1) != 1) {
+                perror("write()");
+                exit(1);
+            }
         } else
 #endif
             fprintf(stderr, "Could not acquire pid file: %s\n", strerror(errno));
@@ -6075,7 +6084,10 @@  int main(int argc, char **argv, char **envp)
 	if (len != 1)
 	    exit(1);
 
-	chdir("/");
+	if (chdir("/")) {
+        perror("chdir()");
+        exit(1);
+    }
 	TFR(fd = qemu_open("/dev/null", O_RDWR));
 	if (fd == -1)
 	    exit(1);
@@ -6094,7 +6106,10 @@  int main(int argc, char **argv, char **envp)
             fprintf(stderr, "chroot failed\n");
             exit(1);
         }
-        chdir("/");
+        if (chdir("/")) {
+            perror("chdir()");
+            exit(1);
+        }
     }
 
     if (run_as) {