pipe() not setting errno.

Hello,

When running out of file descriptors pipe() does return -1 but errno is not set. This is working ok on IA32 systems, but fails on IA64. I've tested this with kernels 2.4.9 and 2.4.18.

Below is a small sample program to illustrate the problem:

########################################################
#include <stdio.h>
#include <errno.h>
#include <unistd.h>

int main (int argc, char **argv){
int i;

  for (i = 0; i < 3000; i++) {
    int fd[2];
    if (-1 = pipe(fd))
      break;
    printf ("%d ", i);

} /* for */
printf ("\npipe number %d error: errno=%d\n", i, errno); return errno;
}
#############################################################

Sample run:

$ ulimit -n 12
$ ./tpipe
0 1 2 3
pipe number 4 error: errno=0

Regards
Anders Herbjørnsen

Anders Herbjørnsen <[email protected]> writes:

|> Hello,
|> 
|> When running out of file descriptors pipe() does return -1 but
|> errno is not set. This is working ok on IA32 systems, but fails
|> on IA64. I've tested this with kernels 2.4.9 and 2.4.18.

It's a bug in glibc, this should fix it:

2002-04-04 Andreas Schwab <[email protected]>

* sysdeps/unix/sysv/linux/ia64/pipe.S: Don't overwrite r8 on error.

@@ -1,4 +1,4 @@
-/* Copyright (C) 1999, 2000 Free Software Foundation, Inc.
+/* Copyright (C) 1999, 2000, 2002 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by David Mosberger <[email protected]>
 

@@ -28,7 +28,7 @@
        cmp.ne p6,p0=-1,r10
        ;;
 (p6)   st4 [r2]=r8,4
-       mov ret0=0
+(p6)   mov ret0=0
        ;;
 (p6)   st4 [r2]=r9
 (p6)   ret

Andreas.

Andreas Schwab, SuSE Labs, [email protected]
SuSE GmbH, Deutschherrnstr. 15-19, D-90429 Nürnberg
Key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

Reply to the message of Thursday April 4, 2002 15:36 +0100
-----------------------------------------------------------------
Andreas Schwab <[email protected] internet> writes:

|> When running out of file descriptors pipe() does return -1 but
|> errno is not set. This is working ok on IA32 systems, but fails
|> on IA64. I've tested this with kernels 2.4.9 and 2.4.18.

Thanks, the patch worked like charm!

Anders

I've applied the patch now. Thanks,

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