Message-ID: <496CCF94.8050304@t-online.de>
Date: Tue, 13 Jan 2009 18:29:56 +0100
From: Bernd Schmidt <bernds_cb1@t-online.de>
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To: Arjan van de Ven <arjan@linux.intel.com>
CC: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
       "Hennerich, Michael" <Michael.Hennerich@analog.com>
Subject: Fix timeouts in sys_pselect7
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Since we (Analog Devices) updated our Blackfin kernel to 2.6.28, we've
seen occasional 5-second hangs from telnet.  telnetd calls select with a
NULL timeout, but with the new kernel, the system call occasionally
returns 0, which causes telnet to call sleep (5).  This did not happen
with earlier kernels.

The code in sys_pselect7 looks a bit strange, in particular the variable
"to" is initialized to NULL, then changed if a non-null timeout was
passed in, but not used further.  The patch below passes it to
core_sys_select instead of &end_time, and this appears to fix the
problem.  Does this look like the correct approach?

Signed-off-by: Bernd Schmidt <bernd.schmidt@analog.com>
-- 
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Analog Devices GmbH      Wilhelm-Wagenfeld-Str. 6      80807 Muenchen
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 fs/select.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/fs/select.c b/fs/select.c
index 08b91be..b0cf1f0 100644
--- a/fs/select.c
+++ b/fs/select.c
@@ -610,7 +610,7 @@ asmlinkage long sys_pselect7(int n, fd_set __user *inp, fd_set __user *outp,
 		sigprocmask(SIG_SETMASK, &ksigmask, &sigsaved);
 	}
 
-	ret = core_sys_select(n, inp, outp, exp, &end_time);
+	ret = core_sys_select(n, inp, outp, exp, to);
 	ret = poll_select_copy_remaining(&end_time, tsp, 0, ret);
 
 	if (ret == -ERESTARTNOHAND) {

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