On Mon, Feb 20, 2017 at 05:11:27PM -0800, Steve Langasek wrote: > On Mon, Feb 20, 2017 at 04:57:53PM -0800, Steve Langasek wrote: > > Package: galera-3 > > Version: 25.3.19-2 > > Severity: normal > > Tags: patch > > User: ubuntu-de...@lists.ubuntu.com > > Usertags: origin-ubuntu zesty ubuntu-patch
> > The galera-3 package was failing to build from source on armhf in Ubuntu, > > because the Ubuntu armhf autobuilders expose unaligned accesses as SIGBUS > > and galera-3's code makes an unaligned access that gets caught by the test > > suite. > > Please find attached a fix for this portability bug. > Well, this wasn't a very good fix; I overlooked that it was not > endian-clean, and the package actually still fails to build on armhf with a > different error. > I will follow up soon with a complete patch. Here is the fixed patch. Cheers, -- Steve Langasek Give me a lever long enough and a Free OS Debian Developer to set it on, and I can move the world. Ubuntu Developer http://www.debian.org/ slanga...@ubuntu.com vor...@debian.org
Description: avoid unaligned access
Fix various unaligned accesses in checksumming,
serialization/deserialization, etc. code. Unaligned access is non-portable.
.
Work around this by using memcpy instead.
Author: Steve Langasek <steve.langa...@ubuntu.com>
Index: galera-3-25.3.19/galera/src/write_set_ng.cpp
===================================================================
--- galera-3-25.3.19.orig/galera/src/write_set_ng.cpp
+++ galera-3-25.3.19/galera/src/write_set_ng.cpp
@@ -165,9 +165,8 @@
compute (ptr, csize, check);
- hcheck = *(reinterpret_cast<const type_t*>(
- reinterpret_cast<const gu::byte_t*>(ptr) + csize
- ));
+ memcpy(&hcheck, reinterpret_cast<const gu::byte_t*>(ptr)+csize,
+ sizeof(type_t));
if (gu_likely(check == hcheck)) return;
Index: galera-3-25.3.19/gcs/src/gcs_state_msg.cpp
===================================================================
--- galera-3-25.3.19.orig/gcs/src/gcs_state_msg.cpp
+++ galera-3-25.3.19/gcs/src/gcs_state_msg.cpp
@@ -174,7 +174,8 @@
strcpy (name, state->name);
strcpy (inc_addr, state->inc_addr);
*appl_proto_ver = state->appl_proto_ver; // in preparation for V1
- *cached = htog64(state->cached);
+ memcpy(cached, &state->cached, sizeof(state->cached));
+ *cached = htog64(*cached);
*desync_count = htog32(state->desync_count);
return ((uint8_t*)(desync_count + 1) - (uint8_t*)buf);
@@ -201,7 +202,8 @@
int64_t* cached_ptr = (int64_t*)(appl_ptr + 1);
if (*version >= 3) {
assert(buf_len >= (uint8_t*)(cached_ptr + 1) - (uint8_t*)buf);
- cached = gtoh64(*cached_ptr);
+ memcpy(&cached, cached_ptr, sizeof(cached));
+ cached = gtoh64(cached);
}
int32_t desync_count = 0;
Index: galera-3-25.3.19/galerautils/src/gu_serialize.hpp
===================================================================
--- galera-3-25.3.19.orig/galerautils/src/gu_serialize.hpp
+++ galera-3-25.3.19/galerautils/src/gu_serialize.hpp
@@ -72,7 +72,8 @@
gu_throw_error(EMSGSIZE) << ret << " > " << buflen;
}
void* const pos(reinterpret_cast<byte_t*>(buf) + offset);
- *reinterpret_cast<TO*>(pos) = htog<TO>(f);
+ TO t_aligned = htog<TO>(f);
+ memcpy(reinterpret_cast<TO*>(pos), &t_aligned, sizeof(t_aligned));
return ret;
}
@@ -91,7 +92,10 @@
gu_throw_error(EMSGSIZE) << ret << " > " << buflen;
}
const void* const pos(reinterpret_cast<const byte_t*>(buf) + offset);
- t = gtoh<FROM>(*reinterpret_cast<const FROM*>(pos));
+ FROM f_aligned;
+ memcpy(&f_aligned, reinterpret_cast<const FROM*>(pos),
+ sizeof(f_aligned));
+ t = gtoh<FROM>(f_aligned);
return ret;
}
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