Re: [Crash-utility] [PATCH] extensions/trace.so: fix MEMBER_OFFSET usage

----- 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(a)axis.com&gt; > 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(a)redhat.com&gt; > 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(a)epam.com) > --- > 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 > > -- Crash-utility mailing list Crash-utility(a)redhat.com https://www.redhat.com/mailman/listinfo/crash-utility