LTTng » LTTng-tools

If lttng_list_tracepoints fails (can't connect to a sessiond for example, I suppose), events_list is freed while not set. Here is the corresponding valgrind trace.

==5531== Memcheck, a memory error detector
==5531== Copyright (C) 2002-2013, and GNU GPL'd, by Julian Seward et al.
==5531== Using Valgrind-3.10.1 and LibVEX; rerun with -h for copyright info
==5531== Command: lttng list -u
==5531== 
Error: Unable to list UST events: No session daemon is available
==5531== Conditional jump or move depends on uninitialised value(s)
==5531==    at 0x4C2A611: free (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==5531==    by 0x40BE43: list_ust_events (list.c:548)
==5531==    by 0x40BE43: cmd_list (list.c:1702)
==5531==    by 0x408F03: handle_command (lttng.c:295)
==5531==    by 0x408F03: parse_args (lttng.c:414)
==5531==    by 0x408F03: main (lttng.c:464)
==5531== 
==5531== Invalid free() / delete / delete[] / realloc()
==5531==    at 0x4C2A65B: free (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==5531==    by 0x40BE43: list_ust_events (list.c:548)
==5531==    by 0x40BE43: cmd_list (list.c:1702)
==5531==    by 0x408F03: handle_command (lttng.c:295)
==5531==    by 0x408F03: parse_args (lttng.c:414)
==5531==    by 0x408F03: main (lttng.c:464)
==5531==  Address 0x401458 is not stack'd, malloc'd or (recently) free'd
==5531== 
Error: Command error
==5531== 
==5531== HEAP SUMMARY:
==5531==     in use at exit: 0 bytes in 0 blocks
==5531==   total heap usage: 45 allocs, 46 frees, 6,885 bytes allocated
==5531== 
==5531== All heap blocks were freed -- no leaks are possible
==5531== 
==5531== For counts of detected and suppressed errors, rerun with: -v
==5531== Use --track-origins=yes to see where uninitialised values come from
==5531== ERROR SUMMARY: 2 errors from 2 contexts (suppressed: 0 from 0)