[rancid] Problem backing up HP switches on RHEL 6.2 (x86_64) -- patch included

[David Byers]

On 2010-06-25 a change was checked in to GNU libc that changes how 
memcpy works on certain architectures. Previously it copied overlapping 
memory regions correctly; now it doesn't.

The net result for rancid is that backups of HP switches don't work on 
e.g. RedHat Enterprise Linux with glibc-2.12-1.47 (x86_64). The output 
gets garbled, and rancid fails to complete the backup process in many 
cases. The cause appears to be memcpy calls in hpuifilter.

The patch below appears to solve the problem (at least our backups look 
OK again); I've simply replaced all memcpy calls with calls to memmove; 
probably some of them don't need to be replaced, but I don't see any 
harm in doing so -- memmove may be a little slower, but I doubt that 
this is a bottleneck in rancid.

Unified diff follows below.

David Byers
Linköping University



--- hpuifilter.c        2012-02-08 09:45:18.427498055 +0100
+++ hpuifilter_org.c    2012-02-08 08:30:28.856503169 +0100
@@ -367,7 +367,7 @@
                 break;
             } else if (bytes > 0) {
                 hlen -= bytes;
-               memmove(hbuf, hbuf + bytes, hlen + 1);
+               memcpy(hbuf, hbuf + bytes, hlen + 1);
                 if (hlen < 1)
                      pfds[2].events &= ~POLLOUT;
             }
@@ -423,7 +423,7 @@
                 break;
             } else if (bytes > 0) {
                 tlen -= bytes;
-               memmove(tbuf, tbuf + bytes, tlen + 1);
+               memcpy(tbuf, tbuf + bytes, tlen + 1);
                 if (tlen < 1)
                     pfds[1].events &= ~POLLOUT;
             }
@@ -593,7 +593,7 @@
             if (len - pmatch[0].rm_eo <= 0) {
                 buf[pmatch[0].rm_so] = '\0';
             } else {
-               memmove(buf + pmatch[0].rm_so, buf + pmatch[0].rm_eo,
+               memcpy(buf + pmatch[0].rm_so, buf + pmatch[0].rm_eo,
                        len - pmatch[0].rm_eo + 1);
             }
             len -= pmatch[0].rm_eo - pmatch[0].rm_so;
@@ -616,7 +616,7 @@
             if (len - pmatch[0].rm_eo == 0) {
                 buf[pmatch[0].rm_so] = '\0';
             } else {
-               memmove(buf + pmatch[0].rm_so, buf + pmatch[0].rm_eo,
+               memcpy(buf + pmatch[0].rm_so, buf + pmatch[0].rm_eo,
                        len - pmatch[0].rm_eo + 1);
             }
             len -= pmatch[0].rm_eo - pmatch[0].rm_so;