I'm not sure why this happens, but the hash_lan function in ipmi_lan.c, when compiled in 64-bit mode, sometimes returns negative numbers, which results in a segfault inside the library. I suspect the games it's playing with pointer math aren't exactly 64-bit clean. Adding an operation to mask the index value to 31 bits after the shift and before the modulo operation clears this up. I doubt it will seriously affect the output of the hash function, since the mask operation is masking off bits that "should" be removed by the modulo operation anyway.
This problem has existed at least as far back as OpenIPMI 2.0.10, where
I first noticed it. When we recently upgraded the version of OpenIPMI
we use to 2.0.14, this problem reared its ugly head again. Hopefully, I
can get this fix in the mainline code and we'll never have to worry
about it again.
diff -Naur OpenIPMI-2.0.14-ORIGINAL/lib/ipmi_lan.c
OpenIPMI-2.0.14/lib/ipmi_lan.c
--- OpenIPMI-2.0.14-ORIGINAL/lib/ipmi_lan.c 2007-10-16
11:46:15.000000000 -0600
+++ OpenIPMI-2.0.14/lib/ipmi_lan.c 2008-11-17 10:48:51.000000000
-0700
@@ -1352,6 +1352,8 @@
idx = (((unsigned long) ipmi)
>> (sizeof(unsigned long) >> LAN_HASH_SHIFT));
+ /* sometimes 64-bit pointer math gets in the way, mask to 31 bits
*/
+ idx &= 0x7FFFFFFF;
idx %= LAN_HASH_SIZE;
return idx;
}
--
Eric J. Bowersox, Software Engineer Aspen Systems, Inc.
<[EMAIL PROTECTED]> 3900 Youngfield Street
Tel: +01 303 431 4606 x113 Wheat Ridge, CO 80033, USA
Fax: +01 303 431 7196 <http://www.aspsys.com>
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