[Crash-utility] [PATCH] extensions/trace: Fix ftrace_get_event_type_name()

The recent kernel change dcb0b5575d24 ("tracing: Remove TRACE_EVENT_FL_USE_CALL_FILTER logic") changed the bit index so it makes checking TRACE_EVENT_FL_TRACEPOINT flag failed. It should be 0x20 for newer kernels. Without this patch, the crash tool refused to load trace.so extension due to invalid access to event names: crash> extend trace.so extend: /path/to/crash/extensions/trace.so: no commands registered: shared object unloaded Instead of using the hard-coded value, read the enum value from the kernel dynamically. Reported-by: Minchan Kim <minchan(a)kernel.org&gt; Cc: Steven Rostedt <rostedt(a)goodmis.org&gt; Signed-off-by: Namhyung Kim <namhyung(a)gmail.com&gt; --- extensions/trace.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/extensions/trace.c b/extensions/trace.c index 782d62f..f8ccd91 100644 --- a/extensions/trace.c +++ b/extensions/trace.c @@ -1015,8 +1015,6 @@ 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) { @@ -1024,8 +1022,9 @@ int ftrace_get_event_type_name(ulong call, char *name, int len) static int name_offset; static int flags_offset; static int tp_name_offset; - uint flags; + static long tracepoint_flag; + uint flags; ulong name_addr; if (inited) @@ -1051,6 +1050,9 @@ int ftrace_get_event_type_name(ulong call, char *name, int len) if (tp_name_offset < 0) return -1; + if (!enumerator_value("TRACE_EVENT_FL_TRACEPOINT", &tracepoint_flag)) + return -1; + inited = 2; work: @@ -1067,7 +1069,7 @@ work: RETURN_ON_ERROR)) return -1; - if (flags & TRACE_EVENT_FL_TRACEPOINT) { + if (flags & (uint)tracepoint_flag) { if (!readmem(name_addr + tp_name_offset, KVADDR, &name_addr, sizeof(name_addr), "read tracepoint name", RETURN_ON_ERROR)) -- 2.8.0