Hi,
Logging code in multipathd cause unaligned access
which, on ia64, yields logs on both console and syslog like:
unaligned access to 0x60000000000141d1, ip=0x4000000000009d81
It's harmless except for the slight performance effect.
However, it's annoying for users and better to fix.
Attached patch aligns the la->tail to pointer size.
Patch is created on multipath-tools 0.4.4.
Please consider to apply.
This is a gdb trace of the case, for your reference:
#0 log_enqueue (prio=5, fmt=0x4000000000045970 "read /etc/multipath.conf",
ap=0x6000000000013f70) at log.c:130
130 msg->prio = prio;
(gdb) where
#0 log_enqueue (prio=5, fmt=0x4000000000045970 "read /etc/multipath.conf",
ap=0x6000000000013f70) at log.c:130
#1 0x400000000000a390 in log_safe (prio=5,
fmt=0x4000000000045970 "read /etc/multipath.conf") at log_pthread.c:16
#2 0x4000000000007f60 in child (param=0x0) at main.c:883
#3 0x2000000000275930 in __clone2 () from /lib/tls/libc.so.6.1
(gdb) p msg
$1 = (struct logmsg *) 0x60000000000141d1
(gdb) p la->tail
$2 = (void *) 0x60000000000141d1
(gdb) p/x fwd
$3 = 0x31
Thanks,
Jun'ichi Nomura
--- multipath-tools-0.4.4/multipathd/log.c.orig 2005-05-04 16:46:14.146824760 -0400
+++ multipath-tools-0.4.4/multipathd/log.c 2005-05-04 17:08:39.212237970 -0400
@@ -89,6 +89,7 @@ void log_close (void)
return;
}
+#define ALIGN(len, s) (((len)+(s)-1)/(s)*(s))
int log_enqueue (int prio, const char * fmt, va_list ap)
{
int len, fwd;
@@ -101,10 +102,10 @@ int log_enqueue (int prio, const char *
if (!la->empty) {
fwd = sizeof(struct logmsg) +
strlen((char *)&lastmsg->str) * sizeof(char) + 1;
- la->tail += fwd;
+ la->tail += ALIGN(fwd, sizeof(void *));
}
vsnprintf(buff, MAX_MSG_SIZE, fmt, ap);
- len = strlen(buff) * sizeof(char) + 1;
+ len = ALIGN(strlen(buff) * sizeof(char) + 1, sizeof(void *));
/* not enough space on tail : rewind */
if (la->head <= la->tail &&
@@ -128,7 +129,7 @@ int log_enqueue (int prio, const char *
la->empty = 0;
msg = (struct logmsg *)la->tail;
msg->prio = prio;
- memcpy((void *)&msg->str, buff, len);
+ memcpy((void *)&msg->str, buff, strlen(buff));
lastmsg->next = la->tail;
msg->next = la->head;
