From: Shlomo Pongratz <shlomop@mellanox.com>
To: linux-scsi@vger.kernel.org
Cc: jayamohank@serverengines.com, michaelc@cs.wisc.edu
Subject: Possible reentrancy issue in be_iopoll
Date: Mon, 18 Mar 2013 17:11:51 +0200 [thread overview]
Message-ID: <51472EB7.2020903@mellanox.com> (raw)
Hi Jayamohan.
I think that there is a reentrancy issue in
"drivers/scsi/be2iscsi/be_main.c::be_iopoll".
The driver creates "NAPI" context per core which is fine, however the
above routine declares the ret variable as static!
Thus there is only one instance of this variable, so if this routine is
called from more than one thread of execution the result is unpredictable.
static unsigned int ret;
.....
ret = beiscsi_process_cq(pbe_eq);
<----------------------------------------------------------------------------------Another
thread can enter here and change "ret".
if (ret < budget) {
....
}
<----------------------------------------------------------------------------------Another
thread can enter here and change "ret".
return ret;
I can't submit a patch without checking it first, which is impossible
since I don't have the HW, but the fix seems trivial, just take out the
static.
Best regards,
S.P.
next reply other threads:[~2013-03-18 15:12 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-18 15:11 Shlomo Pongratz [this message]
2013-03-19 19:42 ` Possible reentrancy issue in be_iopoll Kallickal, Jayamohan
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