----- Original Message -----
> On Tue, Sep 27, 2016 at 02:49:56PM -0400, Dave Anderson wrote:
> > In any case, it seems counter-productive to fix this issue by essentially
> > going backwards and using ANON_MEMBER_OFFSET(), which was a kludge to
> > begin with.
> >
> > Would it be possible to fix this in different manner while continuing to
> > use the new-and-improved MEMBER_OFFSET()?
>
> Just replacing ANON_MEMBER_OFFSET() with MEMBER_OFFSET() in the patch
> works. Here's an updated patch:
Nice! Thanks!
I'll wait a couple days until I hear something from Fujitsu, but if I don't,
I'll probably go ahead and check the patch in anyway -- because I'd like to
release crash-7.1.6 by the end of this week.
Dave
>
> 8<--------------------
> From 4e1b5c07911e9ef815b36970f4ffea71a52a059d Mon Sep 17 00:00:00 2001
> From: Rabin Vincent <rabinv@xxxxxxxx>
> Date: Tue, 27 Sep 2016 19:40:39 +0200
> Subject: [PATCHv2] extensions/trace.so: fix MEMBER_OFFSET usage
>
> In Linux v3.15 the name field of ftrace_event_fall moved into an
> anonymous union (along with a new tp field). The trace extension
> attempt to handle this by first checking if the offset can be
> determined by MEMBER_OFFSET, and if that's the case, assuming that the
> name is not in an anonymous union and thus that the kernel is pre-v3.15.
>
> This used to work, but since the following commit, MEMBER_OFFSET seems
> to even find fields inside anonymous unions, so the code always hits the
> pre-v3.15 path even on newer kernels, preventing the trace extension
> from successfully loading.
>
> Fix this by reworking the checks to check for the tp field first and
> using the presence of that field to identify a post-v3.15 kernel.
>
> commit 5e6fbde738b827e2575aa9ec9ba4b3eb02ac65c5
> Author: Dave Anderson <anderson@xxxxxxxxxx>
> Date: Thu Aug 25 14:26:58 2016 -0400
>
> Enhancement to determine structure member data if the member is
> contained within an anonymous structure or union. Without the patch,
> it is necessary to parse the output of a discrete gdb "printf"
> command to determine the offset of such a structure member.
> (Alexandr_Terekhov@xxxxxxxx)
> ---
> extensions/trace.c | 39 ++++++++++++++++++---------------------
> 1 file changed, 18 insertions(+), 21 deletions(-)
>
> diff --git a/extensions/trace.c b/extensions/trace.c
> index f8ccd91..b226ac0 100644
> --- a/extensions/trace.c
> +++ b/extensions/trace.c
> @@ -1030,30 +1030,27 @@ int ftrace_get_event_type_name(ulong call, char
> *name, int len)
> if (inited)
> goto work;
>
> - inited = 1;
> - name_offset = MAX(MEMBER_OFFSET("ftrace_event_call", "name"),
> - MEMBER_OFFSET("trace_event_call", "name"));
> - if (name_offset >= 0)
> - goto work;
> -
> - name_offset = MAX(ANON_MEMBER_OFFSET("ftrace_event_call", "name"),
> - ANON_MEMBER_OFFSET("trace_event_call", "name"));
> - if (name_offset < 0)
> - return -1;
> -
> - flags_offset = MAX(MEMBER_OFFSET("ftrace_event_call", "flags"),
> - MEMBER_OFFSET("trace_event_call", "flags"));
> - if (flags_offset < 0)
> - return -1;
> + name_offset = MAX(MEMBER_OFFSET("ftrace_event_call", "tp"),
> + MEMBER_OFFSET("trace_event_call", "tp"));
> + if (name_offset >= 0) {
> + flags_offset = MAX(MEMBER_OFFSET("ftrace_event_call", "flags"),
> + MEMBER_OFFSET("trace_event_call", "flags"));
> + if (flags_offset < 0)
> + return -1;
>
> - tp_name_offset = MEMBER_OFFSET("tracepoint", "name");
> - if (tp_name_offset < 0)
> - return -1;
> + tp_name_offset = MEMBER_OFFSET("tracepoint", "name");
> + if (tp_name_offset < 0)
> + return -1;
>
> - if (!enumerator_value("TRACE_EVENT_FL_TRACEPOINT", &tracepoint_flag))
> - return -1;
> + if (!enumerator_value("TRACE_EVENT_FL_TRACEPOINT", &tracepoint_flag))
> + return -1;
>
> - inited = 2;
> + inited = 2;
> + } else {
> + name_offset = MAX(MEMBER_OFFSET("ftrace_event_call", "name"),
> + MEMBER_OFFSET("trace_event_call", "name"));
> + inited = 1;
> + }
>
> work:
> if (name_offset < 0)
> --
> 2.1.4
>
>
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