Re: [Crash-utility] [PATCH] Fix trace extension for v3.15+

Since Linux v3.15 (specifically, the following commit), the event name is optionally moved to another structure. commit de7b2973903c6cc50b31ee5682a69b2219b9919d Author: Mathieu Desnoyers&lt;mathieu.desnoyers(a)efficios.com&gt; Date: Tue Apr 8 17:26:21 2014 -0400 tracepoint: Use struct pointer instead of name hash for reg/unreg tracepoints - char *name; + union { + char *name; + /* Set TRACE_EVENT_FL_TRACEPOINT flag when using "tp" */ + struct tracepoint *tp; + }; This patch handles this in the trace extension so that both kernels with and without that commit work. --- extensions/trace.c | 46 ++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 42 insertions(+), 4 deletions(-) diff --git a/extensions/trace.c b/extensions/trace.c index a09f6a1..8639fb2 100644 --- a/extensions/trace.c +++ b/extensions/trace.c @@ -988,19 +988,42 @@ static void ftrace_destroy_event_types(void) free(ftrace_common_fields); } +#define TRACE_EVENT_FL_TRACEPOINT 0x40 + static int ftrace_get_event_type_name(ulong call, char *name, int len) { static int inited; static int name_offset; + static int flags_offset; + static int tp_name_offset; + uint flags; ulong name_addr; - if (!inited) { - inited = 1; - name_offset = MEMBER_OFFSET("ftrace_event_call", "name"); - } + if (inited) + goto work; + + inited = 1; + name_offset = MEMBER_OFFSET("ftrace_event_call", "name"); + if (name_offset>= 0) + goto work; + name_offset = ANON_MEMBER_OFFSET("ftrace_event_call", "name"); + if (name_offset< 0) + return -1; + + flags_offset = MEMBER_OFFSET("ftrace_event_call", "flags"); + if (flags_offset< 0) + return -1; + + tp_name_offset = MEMBER_OFFSET("tracepoint", "name"); + if (tp_name_offset< 0) + return -1; + + inited = 2; + +work: if (name_offset< 0) return -1; @@ -1008,6 +1031,21 @@ int ftrace_get_event_type_name(ulong call, char *name, int len) "read ftrace_event_call name_addr", RETURN_ON_ERROR)) return -1; + if (inited == 2) { + if (!readmem(call + flags_offset, KVADDR,&flags, + sizeof(flags), "read ftrace_event_call flags", + RETURN_ON_ERROR)) + return -1; + + if (flags& TRACE_EVENT_FL_TRACEPOINT) { + if (!readmem(name_addr + tp_name_offset, KVADDR, + &name_addr, sizeof(name_addr), + "read tracepoint name", RETURN_ON_ERROR)) + return -1; + } + + } + if (!read_string(name_addr, name, len)) return -1;