linux-kernel - Re: [PATCH v6 8/8] perf buildid-cache: recognize vdso when adding files

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] [day] [month] [year] [list]

Message-ID: <953cc060c1a24e36abf797918824d13e@huawei.com>
Date: Thu, 12 Sep 2024 11:10:10 +0000
From: duchangbin <changbin.du@...wei.com>
To: Adrian Hunter <adrian.hunter@...el.com>
CC: duchangbin <changbin.du@...wei.com>, Peter Zijlstra
	<peterz@...radead.org>, Ingo Molnar <mingo@...hat.com>, "Arnaldo Carvalho de
 Melo" <acme@...nel.org>, Namhyung Kim <namhyung@...nel.org>, Nathan
 Chancellor <nathan@...nel.org>, Mark Rutland <mark.rutland@....com>,
	Alexander Shishkin <alexander.shishkin@...ux.intel.com>, Jiri Olsa
	<jolsa@...nel.org>, "Ian Rogers" <irogers@...gle.com>, "Liang, Kan"
	<kan.liang@...ux.intel.com>, "Nick Desaulniers" <ndesaulniers@...gle.com>,
	Bill Wendling <morbo@...gle.com>, Justin Stitt <justinstitt@...gle.com>,
	"linux-perf-users@...r.kernel.org" <linux-perf-users@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"llvm@...ts.linux.dev" <llvm@...ts.linux.dev>, "Wanghui (OS Kernel Lab,
 Beijing)" <hw.huiwang@...wei.com>
Subject: Re: [PATCH v6 8/8] perf buildid-cache: recognize vdso when adding
 files

On Wed, Sep 11, 2024 at 11:05:20AM +0300, Adrian Hunter wrote:
> On 25/07/24 05:15, Changbin Du wrote:
> > Identify vdso by file name matching. The vdso objects have name
> > as vdso[32,64].so[.dbg].
> > 
> > $ perf buildid-cache -a /work/linux/arch/x86/entry/vdso/vdso64.so.dbg
> > 
> > Without this change, adding vdso using above command actually will never
> > be used.
> > 
> > Signed-off-by: Changbin Du <changbin.du@...wei.com>
> 
> A couple of comments, but address those then add:
> 
> Reviewed-by: Adrian Hunter <adrian.hunter@...el.com>
> 
> > ---
> >  tools/perf/builtin-buildid-cache.c | 26 +++++++++++++++++++++++++-
> >  1 file changed, 25 insertions(+), 1 deletion(-)
> > 
> > diff --git a/tools/perf/builtin-buildid-cache.c b/tools/perf/builtin-buildid-cache.c
> > index b0511d16aeb6..8edea9044a65 100644
> > --- a/tools/perf/builtin-buildid-cache.c
> > +++ b/tools/perf/builtin-buildid-cache.c
> > @@ -172,6 +172,30 @@ static int build_id_cache__add_kcore(const char *filename, bool force)
> >  	return 0;
> >  }
> >  
> > +static bool filename_is_vdso(const char *filename)
> > +{
> > +	char *fname, *bname;
> > +	static const char * const vdso_names[] = {
> > +		"vdso.so", "vdso32.so", "vdso64.so", "vdsox32.so"
> > +	};
> > +
> > +	fname = strdup(filename);
> > +	if (!fname) {
> > +		pr_err("no mememory\n");
> 
> mememory -> memory
>
fixed.

> > +		return false;
> > +	}
> 
> fname is never freed.
> 
fixed.

> > +
> > +	bname = basename(fname);
> > +	if (!bname)
> > +		return false;
> > +
> > +	for (unsigned int i = 0; i < ARRAY_SIZE(vdso_names); i++) {
> 
> 'unsigned' is unnecessary
> 
This is required to supress this error.
error: comparison of integer expressions of different signedness: ‘int’ and ‘long unsigned int’

> > +		if (!strncmp(bname, vdso_names[i], strlen(vdso_names[i])))
> 
> Use strstarts()
> 
okay.

> > +			return true;
> > +	}
> > +	return false;
> > +}
> > +
> >  static int build_id_cache__add_file(const char *filename, struct nsinfo *nsi)
> >  {
> >  	char sbuild_id[SBUILD_ID_SIZE];
> > @@ -189,7 +213,7 @@ static int build_id_cache__add_file(const char *filename, struct nsinfo *nsi)
> >  
> >  	build_id__sprintf(&bid, sbuild_id);
> >  	err = build_id_cache__add_s(sbuild_id, filename, nsi,
> > -				    false, false);
> > +				    false, filename_is_vdso(filename));
> >  	pr_debug("Adding %s %s: %s\n", sbuild_id, filename,
> >  		 err ? "FAIL" : "Ok");
> >  	return err;
> 
> 

-- 
Cheers,
Changbin Du