[Python-bugs-list] [ python-Bugs-821948 ] fcntl() not working on sparc (python 2.2.3)

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Bugs item #821948, was opened at 2003-10-11 19:08
Message generated for change (Comment added) made by albertogli
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https://sourceforge.net/tracker/?func=detail&atid=105470&aid=821948&group_id=5470

Category: Extension Modules
Group: Platform-specific
Status: Open
Resolution: None
Priority: 5
Submitted By: Alberto Bertogli (albertogli)
Assigned to: Nobody/Anonymous (nobody)
Summary: fcntl() not working on sparc (python 2.2.3)

Initial Comment:
In sparc, fcntl.fcntl() is not working properly under
Python 2.2.3;
a simple strace of:

import fcntl, sys
fcntl.fcntl(sys.stdin.fileno(), fcntl.F_SETFL,
os.O_NONBLOCK)

will reveal that on sparc there's no fcntl() syscall
done, while
under x86 it works as expected (ie. the syscall is there).

I have not tested yet with Python 2.3 but I'll let you
know when I do.

Thanks,
    Alberto


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>Comment By: Alberto Bertogli (albertogli)
Date: 2003-10-14 00:31

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I'm attaching both, tar.bz2 compressed, about 45k, without any
stripping whatsoever.

Linux on Sparc userspace is always 32 bit, but the kernel 
is 64 bit on sparc64 and 32 bit on sparc32.

In this case, userspace is 32 bit and kernel 64 bit.


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Comment By: Martin v. Löwis (loewis)
Date: 2003-10-13 18:33

Message:
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It would be good if you could attach preprocessor output and
assembler code (both obtained through --save-temps) for
fcntlmodule.c. If this is too large to attach you might need
to compress it, if it is then still too large, you would
need to strip all but fcntl_fcntl.

Also, are you using a 32-bit or a 64-bit compiler?

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Comment By: Alberto Bertogli (albertogli)
Date: 2003-10-13 14:06

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I'm sorry I didn't specify earlier, this is a box running Linux
(gentoo distribution) with:

Linux Kernel 2.4.20
glibc 2.2.5
gcc 2.95.3
python 2.2.3

The fragment of the strace output is the following, it's
between I 
press the final '\n' and the response '0\n' appears:

write(1, "\n", 1)                       = 1
rt_sigprocmask(SIG_BLOCK, [INT], [32], 8) = 0
ioctl(0, 0x8024540a, {B38400 opost isig icanon echo ...}) = 0
rt_sigprocmask(SIG_SETMASK, [32], NULL, 8) = 0
rt_sigaction(SIGINT, {0x700486f8, [], 0}, {0x700486f8, [],
0}, 0x701431c8, 8) = 0
rt_sigaction(SIGTERM, {SIG_DFL}, {0x700486f8, [], 0},
0x701431c8, 8) = 0
rt_sigaction(SIGQUIT, {SIG_DFL}, {0x700486f8, [], 0},
0x701431c8, 8) = 0
rt_sigaction(SIGALRM, {SIG_DFL}, {0x700486f8, [], 0},
0x701431c8, 8) = 0
rt_sigaction(SIGTSTP, {SIG_DFL}, {0x700486f8, [], 0},
0x701431c8, 8) = 0
rt_sigaction(SIGTTOU, {SIG_DFL}, {0x700486f8, [], 0},
0x701431c8, 8) = 0
rt_sigaction(SIGTTIN, {SIG_DFL}, {0x700486f8, [], 0},
0x701431c8, 8) = 0
rt_sigaction(SIGWINCH, {SIG_DFL}, {0x700486f8, [], 0},
0x701431c8, 8) = 0
rt_sigaction(SIGINT, NULL, {0x700486f8, [], 0}, 0, 8) = 0
rt_sigaction(SIGINT, {0x700486f8, [], 0}, NULL, 0x701431c8,
8) = 0
nfssvc(0)                               = 0
write(1, "0\n", 2)                      = 2

On x86 the fcntl64() syscall happens right before the write().

I don't think the bug is present in earlier versions of
Python because I
remember this used to work fine before the upgrade, however
I can't
pinpoint the exact release this started to show up.

Let me know if you need additional info or want me to do
some tests.

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Comment By: Martin v. Löwis (loewis)
Date: 2003-10-12 14:41

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I cannot reproduce this. My binary of 2.2.1 does

read(3, "import fcntl, sys, os\nfcntl.fcnt"..., 8192) = 84
read(3, "", 8192)                       = 0
llseek(3, 0, SEEK_CUR)                  = 0
close(3)                                = 0
fstat64(0, {st_mode=S_IFCHR|0620, st_rdev=makedev(24, 3),
...}) = 0
fcntl(0, F_SETFL, O_RDONLY|O_NONBLOCK)  = 0
sigaction(SIGINT, NULL, {0xff25ff24, ~[KILL STOP], 0}) = 0
sigaction(SIGINT, {SIG_DFL}, NULL)      = 0

Can you attach your strace output? Can you also try truss?
What Solaris version and patches, what compiler?

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