[Crash-utility] [PATCH] Fix the extension trace.so for RHEL7.6

Fix the extension trace.so for RHEL7.6 ,which moved ftrace_event_call.data into an anonymous union,and the previous offset has changed, so the trace.so extension module fails to load ,indicating "no commands registered: shared object unloaded". --- extensions/trace.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/extensions/trace.c b/extensions/trace.c index 7d76699..ad71951 100644 --- a/extensions/trace.c +++ b/extensions/trace.c @@ -853,8 +853,18 @@ static int syscall_get_enter_fields(ulong call, ulong *fields) inited = 1; data_offset = MAX(MEMBER_OFFSET("ftrace_event_call", "data"), MEMBER_OFFSET("trace_event_call", "data")); - if (data_offset < 0) - return -1; + if (data_offset < 0) { + /* + * rhel-7.6 moved the .data member into an anonymous union. + */ + if (MEMBER_EXISTS("ftrace_event_call", "rh_data") && + MEMBER_EXISTS("ftrace_event_data", "data")) { + data_offset = MEMBER_OFFSET("ftrace_event_call", "rh_data") + + MEMBER_OFFSET("ftrace_event_data", "data"); + inited = 2; + } else + return -1; + } enter_fields_offset = MEMBER_OFFSET("syscall_metadata", "enter_fields"); if (enter_fields_offset < 0) @@ -868,6 +878,12 @@ work: "read ftrace_event_call data", RETURN_ON_ERROR)) return -1; + if (inited == 2) { + if (!readmem(metadata, KVADDR, &metadata, sizeof(metadata), + "read ftrace_event_call data (indirect rh_data)", RETURN_ON_ERROR)) + return -1; + } + *fields = metadata + enter_fields_offset; return 0; } -- 2.17.1