Public bug reported: Decoding an lttng user space trace on an ARM platform results in a bus error. Gdb shows this to be:
0x4004358c in yyparse (scanner=0x19fe0, yyscanner=0x199f0) at ctf-parser.y:1210 1210 $$->u.unary_expression.u.unsigned_constant = $1; (gdb) where #0 0x4004358c in yyparse (scanner=0x19fe0, yyscanner=0x199f0) at ctf-parser.y:1210 #1 0x400380ca in ctf_trace_metadata_read (td=td@entry=0x1a600, metadata_fp=metadata_fp@entry=0x0, scanner=0x19fe0, append=append@entry=0) at ctf.c:1281 #2 0x40039d38 in ctf_open_trace_read (metadata_fp=0x0, packet_seek=0x40039295 <ctf_packet_seek>, flags=0, path=0x19ab0 "/home/phablet/lttng-traces/auto-20130101-023753/ust/uid/0/32-bit", td=0x1a600) at ctf.c:2111 #3 ctf_open_trace ( path=0x19ab0 "/home/phablet/lttng-traces/auto-20130101-023753/ust/uid/0/32-bit", flags=0, packet_seek=0x40039295 <ctf_packet_seek>, metadata_fp=0x0) at ctf.c:2206 #4 0x400242f8 in bt_context_add_trace (ctx=ctx@entry=0x15f30, path=0x19ab0 "/home/phablet/lttng-traces/auto-20130101-023753/ust/uid/0/32-bit", format_name=format_name@entry=0x15ff0 "ctf", packet_seek=packet_seek@entry=0x0, stream_list=stream_list@entry=0x0, metadata=metadata@entry=0x0) at context.c:95 #5 0x0000a7d2 in bt_context_add_traces_recursive (ctx=ctx@entry=0x15f30, path=path@entry=0x18968 "/home/phablet/lttng-traces/auto-20130101-023753", format_str=0x15ff0 "ctf", packet_seek=packet_seek@entry=0x0) at babeltrace.c:529 #6 0x00009c86 in main (argc=<optimized out>, argv=<optimized out>) A workaround is to enable misaligned access handling in the kernel: echo 2 | sudo tee /proc/cpu/alignment Alternatively, making struct ctf_node in formats/ctf/metadata/ctf-ast.h packed using the gcc attribute __attribute__((packed())) seems to stop this. I think this is reported upstream too: https://bugs.lttng.org/issues/789 ** Affects: babeltrace (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1316617 Title: babeltrace unaligned access bus errors To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/babeltrace/+bug/1316617/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs