* Re: [SCM] systemtap: system-wide probe/trace tool branch, master, updated. release-0.9.8-184-gf982c59 [not found] <20090721012207.17368.qmail@sourceware.org> @ 2009-07-21 11:19 ` Mark Wielaard 2009-07-22 2:40 ` Josh Stone 0 siblings, 1 reply; 2+ messages in thread From: Mark Wielaard @ 2009-07-21 11:19 UTC (permalink / raw) To: systemtap; +Cc: Josh Stone Hi Josh, On Tue, 2009-07-21 at 01:22 +0000, jistone@sourceware.org wrote: > commit 0c16d51256bc77c2b5497b72ec43b7864d2b47a8 > Author: Josh Stone <jistone@redhat.com> > Date: Mon Jul 20 16:32:33 2009 -0700 > > Allow dwflpp to take a vector of module names > > This will be used to load tracepoint modules as a bunch of little query > modules into a single dwflpp. > > * dwflpp.cxx (setup_user): take a vector instead of a single module > (dwflpp::dwflpp): form a vector in the singular case, and add a > variant that takes and passes through a vector of modules. This breaks user space mark probing. See make installcheck RUNTESTFLAGS="sdt.exp exelib.exp" for example. Most stuff will fail with "semantic error: libdwfl failure (getshdrstrndx): no error while resolving probe point" Which comes from dwarf_builder::probe_table::probe_table(). What goes wrong is that probe_table will try to fetch the probe table (initiated through dwarf_builder::build) from the dw module (initialized through dw = get_user_dw(sess, module_name)), if (get_param(parameters, TOK_MARK, mark_name)). But at that point dw->module isn't setup yet. I am not completely sure how to correct this. The following hack makes things work as before: diff --git a/dwflpp.cxx b/dwflpp.cxx index 0bba3f1..38be86b 100644 --- a/dwflpp.cxx +++ b/dwflpp.cxx @@ -418,6 +418,7 @@ dwflpp::setup_user(const vector<string>& modules, bool debug module_name.c_str(), -1); // XXX: save mod! + module = mod; if (debuginfo_needed) dwfl_assert (string("missing process ") + That works, since it mimics what happened before your patch. And because there is really only one module name in the vector anyway. I checked it in so things at least work again for now. But it seems there must be a better/more elegant solution. Cheers, Mark ^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [SCM] systemtap: system-wide probe/trace tool branch, master, updated. release-0.9.8-184-gf982c59 2009-07-21 11:19 ` [SCM] systemtap: system-wide probe/trace tool branch, master, updated. release-0.9.8-184-gf982c59 Mark Wielaard @ 2009-07-22 2:40 ` Josh Stone 0 siblings, 0 replies; 2+ messages in thread From: Josh Stone @ 2009-07-22 2:40 UTC (permalink / raw) To: Mark Wielaard; +Cc: systemtap On 07/21/2009 04:18 AM, Mark Wielaard wrote: > Hi Josh, > > On Tue, 2009-07-21 at 01:22 +0000, jistone@sourceware.org wrote: >> commit 0c16d51256bc77c2b5497b72ec43b7864d2b47a8 >> Author: Josh Stone <jistone@redhat.com> >> Date: Mon Jul 20 16:32:33 2009 -0700 >> >> Allow dwflpp to take a vector of module names >> >> This will be used to load tracepoint modules as a bunch of little query >> modules into a single dwflpp. >> >> * dwflpp.cxx (setup_user): take a vector instead of a single module >> (dwflpp::dwflpp): form a vector in the singular case, and add a >> variant that takes and passes through a vector of modules. > > This breaks user space mark probing. See make installcheck > RUNTESTFLAGS="sdt.exp exelib.exp" for example. > > Most stuff will fail with "semantic error: libdwfl failure > (getshdrstrndx): no error while resolving probe point" > Which comes from dwarf_builder::probe_table::probe_table(). > What goes wrong is that probe_table will try to fetch the probe table > (initiated through dwarf_builder::build) from the dw module (initialized > through dw = get_user_dw(sess, module_name)), if (get_param(parameters, > TOK_MARK, mark_name)). But at that point dw->module isn't setup yet. Clearly I didn't test the userspace stuff. :( But as always, thanks for being an excellent watchdog, Mark! > I am not completely sure how to correct this. > The following hack makes things work as before: > > diff --git a/dwflpp.cxx b/dwflpp.cxx > index 0bba3f1..38be86b 100644 > --- a/dwflpp.cxx > +++ b/dwflpp.cxx > @@ -418,6 +418,7 @@ dwflpp::setup_user(const vector<string>& modules, bool debug > module_name.c_str(), > -1); > // XXX: save mod! > + module = mod; > > if (debuginfo_needed) > dwfl_assert (string("missing process ") + > > That works, since it mimics what happened before your patch. And because > there is really only one module name in the vector anyway. > > I checked it in so things at least work again for now. > But it seems there must be a better/more elegant solution. I just checked in a rework to make SDT behave more like the other dwarf queries that we have. Now it will iterate over whatever modules are present (all one of them). Hopefully that's a little more elegant for you... :) Josh ^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2009-07-22 2:40 UTC | newest] Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- [not found] <20090721012207.17368.qmail@sourceware.org> 2009-07-21 11:19 ` [SCM] systemtap: system-wide probe/trace tool branch, master, updated. release-0.9.8-184-gf982c59 Mark Wielaard 2009-07-22 2:40 ` Josh Stone
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