Source: nanomsg Version: 1.1.5+dfsg-1 Severity: important User: debian-...@lists.debian.org Usertags: alignment
Hi! I've been doing a full rebuild of the Debian archive, building all source packages targeting armel and armhf using arm64 hardware. We are planning in future to move all of our 32-bit armel/armhf builds to using arm64 machines, so this rebuild is to identify packages that might have problems with this configuration. A feature of the arm64 kernel is that it does *not* support fixing up code with broken alignment, so code that might have built and run OK on our older armel/armhf build machines due to kernel fixups will now fail. When building your package, I've found a bus error (aka alignment fault). The full log is online at https://www.einval.com/debian/arm/rebuild-logs/armel/FAIL/nanomsg_1.1.5+dfsg-1_armel.log for reference I've done a quick bit of debugging to find the source of the bug. Here's a gdb stacktrace and variable printout to demonstrate the problem. (sid-armel)steve@mjolnir:~/debian/build/nanomsg/nanomsg-1.1.5+dfsg$ gdb obj-arm-linux-gnueabi/ws_async_shutdown obj-arm-linux-gnueabi/core ... warning: core file may not match specified executable file. [New LWP 5270] [New LWP 5271] [New LWP 5268] [New LWP 5277] [New LWP 5275] [New LWP 5278] [New LWP 5269] [New LWP 5272] [New LWP 5273] [New LWP 5276] [New LWP 5274] [New LWP 5279] [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/arm-linux-gnueabi/libthread_db.so.1". Core was generated by `/home/steve/debian/build/nanomsg/nanomsg-1.1.5+dfsg/obj-arm-linux-gnueabi/ws_as'. Program terminated with signal SIGBUS, Bus error. #0 0xf7d14b58 in nn_sws_recv (self=0x17ed380, msg=0x0) at ./src/transports/ws/sws.c:573 573 cmsg->cmsg_level = NN_WS; [Current thread is 1 (Thread 0xf7316460 (LWP 5270))] (gdb) p cmsg $1 = (struct nn_cmsghdr *) 0xf7315d9d (gdb) p *cmsg $2 = {cmsg_len = 0, cmsg_level = 0, cmsg_type = 0} (gdb) p cmsg->smsg_level There is no member named smsg_level. (gdb) p cmsg->cmsg_level $3 = 0 (gdb) p &cmsg->cmsg_level $4 = (int *) 0xf7315da1 The definition of nn_cmsghdr: struct nn_cmsghdr { size_t cmsg_len; int cmsg_level; int cmsg_type; }; says that cmsg_level is an int, but the structure here is not aligned appropriately. -- System Information: Debian Release: 9.6 APT prefers stable-updates APT policy: (500, 'stable-updates'), (500, 'stable-debug'), (500, 'stable') Architecture: amd64 (x86_64) Foreign Architectures: i386 Kernel: Linux 4.9.0-8-amd64 (SMP w/4 CPU cores) Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8), LANGUAGE=en_GB.UTF-8 (charmap=UTF-8) Shell: /bin/sh linked to /bin/dash Init: systemd (via /run/systemd/system)
