Date: Fri, 13 May 2005 15:28:46 +0200 From: Hans Petter Selasky <hselasky@c2i.net> To: FreeBSD-gnats-submit@FreeBSD.org Subject: kern/80980: problem in "sys/i386/include/bus.h" cause random freezes Message-ID: <200505131528.46810.hselasky@c2i.net> Resent-Message-ID: <200505131330.j4DDU10h015220@freefall.freebsd.org>
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>Number: 80980
>Category: kern
>Synopsis: problem in "sys/i386/include/bus.h" cause random freezes
>Confidential: no
>Severity: serious
>Priority: high
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Fri May 13 13:30:01 GMT 2005
>Closed-Date:
>Last-Modified:
>Originator: HPS
>Release: FreeBSD 6.0-CURRENT i386
>Organization:
>Environment:
System: FreeBSD 6.0-CURRENT FreeBSD 6.0-CURRENT #45: Mon Mar 21 15:40:17 CET
2005 root@:/usr/obj/usr/src/sys/custom i386
>Description:
When using I386_BUS_SPACE_MEM, neither "bus_space_read_XXX" nor
"bus_space_write_XXX" checks for length/count equal to zero. This can cause
random freezes with some drivers.
Actually the code is like this, just in assembly:
while(--count)
{
I/O
}
which is not correct. This happens several places in "sys/i386/include/bus.h".
>How-To-Repeat:
bus_space_read_multi_2(t,h,0,&buf[0],0); will freeze the system !
"t","h", and "buf" must be valid though, and "t" must equal
I386_BUS_SPACE_MEM.
>Fix:
Wrap all "__asm __volatile" statements inside:
if(count != 0)
{
}
>Release-Note:
>Audit-Trail:
>Unformatted:
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