Re: [PATCH] perf unwind: Set userdata for all __report_module paths

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Thu, Feb 18, 2021 at 04:58:44PM +0000, Dave Rigby escreveu:
> I missed adding a link to the bugzilla issue: https://bugzilla.kernel.org/show_bug.cgi?id=211801
> 
> Note sure what the recommended way of tagging that in the patch is…

You also forgot to add your:

Signed-off-by: Dave Rigby <d.rigby@me.com>

I'm adding it, ok?

Please take a look at Documentation/process/submitting-patches.rst, this
part:

----------------------------------------------------------------------------
Developer's Certificate of Origin 1.1
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

By making a contribution to this project, I certify that:

        (a) The contribution was created in whole or in part by me and I
            have the right to submit it under the open source license
            indicated in the file; or

        (b) The contribution is based upon previous work that, to the best
            of my knowledge, is covered under an appropriate open source
            license and I have the right under that license to submit that
            work with modifications, whether created in whole or in part
            by me, under the same open source license (unless I am
            permitted to submit under a different license), as indicated
            in the file; or

        (c) The contribution was provided directly to me by some other
            person who certified (a), (b) or (c) and I have not modified
            it.

        (d) I understand and agree that this project and the contribution
            are public and that a record of the contribution (including all
            personal information I submit with it, including my sign-off) is
            maintained indefinitely and may be redistributed consistent with
            this project or the open source license(s) involved.

then you just add a line saying::

        Signed-off-by: Random J Developer <random@developer.example.org>

using your real name (sorry, no pseudonyms or anonymous contributions.)
This will be done for you automatically if you use ``git commit -s``.
Reverts should also include "Signed-off-by". ``git revert -s`` does that
for you.

Some people also put extra tags at the end.  They'll just be ignored for
now, but you can do this to mark internal company procedures or just
point out some special detail about the sign-off.

Any further SoBs (Signed-off-by:'s) following the author's SoB are from
people handling and transporting the patch, but were not involved in its
development. SoB chains should reflect the **real** route a patch took
as it was propagated to the maintainers and ultimately to Linus, with
the first SoB entry signalling primary authorship of a single author.
----------------------------------------------------------------------------
 
> 
> DaveR
> 
> > On 18 Feb 2021, at 16:56, d.rigby@me.com wrote:
> > 
> > From: Dave Rigby <d.rigby@me.com>
> > 
> > When locating the dwarf module for a given address, __find_debuginfo()
> > requires a 'struct dso' passed via the userdata argument.
> > 
> > However, this field is only set in __report_module() if the module is
> > found in via dwfl_addrmodule(), not if it is found later via dwfl_report_elf().
> > 
> > Set userdata irrespective of how the dwarf module was found, as long
> > as we found a module.
> > 
> > Fixes: bf53fc6b5f41 ("perf unwind: Fix separate debug info files when using elfutils' libdw's unwinder")
> > Cc: linux-perf-users@vger.kernel.org
> > Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
> > Cc: Jan Kratochvil <jan.kratochvil@redhat.com>
> > Cc: Jiri Olsa <jolsa@redhat.com>
> > ---
> > tools/perf/util/unwind-libdw.c | 11 ++++++++---
> > 1 file changed, 8 insertions(+), 3 deletions(-)
> > 
> > diff --git a/tools/perf/util/unwind-libdw.c b/tools/perf/util/unwind-libdw.c
> > index 0ada907..a74b517 100644
> > --- a/tools/perf/util/unwind-libdw.c
> > +++ b/tools/perf/util/unwind-libdw.c
> > @@ -60,10 +60,8 @@ static int __report_module(struct addr_location *al, u64 ip,
> > 	mod = dwfl_addrmodule(ui->dwfl, ip);
> > 	if (mod) {
> > 		Dwarf_Addr s;
> > -		void **userdatap;
> > 
> > -		dwfl_module_info(mod, &userdatap, &s, NULL, NULL, NULL, NULL, NULL);
> > -		*userdatap = dso;
> > +		dwfl_module_info(mod, NULL, &s, NULL, NULL, NULL, NULL, NULL);
> > 		if (s != al->map->start - al->map->pgoff)
> > 			mod = 0;
> > 	}
> > @@ -79,6 +77,13 @@ static int __report_module(struct addr_location *al, u64 ip,
> > 					      al->map->start - al->map->pgoff, false);
> > 	}
> > 
> > +	if (mod) {
> > +		void **userdatap;
> > +
> > +		dwfl_module_info(mod, &userdatap, NULL, NULL, NULL, NULL, NULL, NULL);
> > +		*userdatap = dso;
> > +	}
> > +
> > 	return mod && dwfl_addrmodule(ui->dwfl, ip) == mod ? 0 : -1;
> > }
> > 
> > -- 
> > 1.8.3.1
> 

-- 

- Arnaldo