linux-kernel - Re: [PATCH 3/3] perf jvmti: Fix demangling Java symbols

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20200527223405.GE16490@kernel.org>
Date:   Wed, 27 May 2020 19:34:05 -0300
From:   Arnaldo Carvalho de Melo <acme@...nel.org>
To:     Nick Gasson <nick.gasson@....com>
Cc:     Ian Rogers <irogers@...gle.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...hat.com>,
        Mark Rutland <mark.rutland@....com>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Jiri Olsa <jolsa@...hat.com>,
        Namhyung Kim <namhyung@...nel.org>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 3/3] perf jvmti: Fix demangling Java symbols

Em Wed, May 27, 2020 at 01:23:00PM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Wed, May 27, 2020 at 11:20:57AM -0300, Arnaldo Carvalho de Melo escreveu:
> > Em Mon, Apr 27, 2020 at 02:15:16PM +0800, Nick Gasson escreveu:
> > > For a Java method signature like:
> > > 
> > >     Ljava/lang/AbstractStringBuilder;appendChars(Ljava/lang/String;II)V
> > > 
> > > The demangler produces:
> > > 
> > >     void class java.lang.AbstractStringBuilder.appendChars(class java.lang., shorttring., int, int)
> > > 
> > > The arguments should be (java.lang.String, int, int) but the demangler
> > > interprets the "S" in String as the type code for "short". Correct this
> > > and two other minor things:
> > > 
> > > - There is no "bool" type in Java, should be "boolean".
> > > 
> > > - The demangler prepends "class" to every Java class name. This is not
> > >   standard Java syntax and it wastes a lot of horizontal space if the
> > >   signature is long. Remove this as there isn't any ambiguity between
> > >   class names and primitives.
> > > 
> > > Also added a test case.
> > 
> > So, I took this and split into a patch for the new 'perf test java' and
> > then the fix, so that we can see the problem being detected and then
> > apply the fix and see it fixed, the last patch in this series thus
> > became:
> 
> This is in my tmp.perf/core branch pending a round of testing, after
> that it'll move to perf/core on its way to 5.8, thanks.

All tests passed, moved to perf/core.

- Arnaldo