perf tools: Fix lockup using 32-bit compat vdso (6d545a63) · Commits · 戴 / test

The __machine__findnew_compat() function is called only from __machine__findnew_vdso_compat() which is called only from machine__findnew_vdso() which already holds machine->dsos.lock, so remove locking from __machine__findnew_compat(). This manifests itself tracing 32-bit programs with a 64-bit perf. Signed-off-by:

Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: http://lkml.kernel.org/r/1436267618-20521-1-git-send-email-adrian.hunter@intel.com Signed-off-by:

Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/vdso.c

+3 −5

Original line number	Original line	Diff line number	Diff line
	@@ -236,18 +236,16 @@ static struct dso __machine__findnew_compat(struct machine machine,
	const char *file_name;		const char *file_name;
	struct dso *dso;		struct dso *dso;

	pthread_rwlock_wrlock(&machine->dsos.lock);
	dso = __dsos__find(&machine->dsos, vdso_file->dso_name, true);		dso = __dsos__find(&machine->dsos, vdso_file->dso_name, true);
	if (dso)		if (dso)
	goto out_unlock;		goto out;

	file_name = vdso__get_compat_file(vdso_file);		file_name = vdso__get_compat_file(vdso_file);
	if (!file_name)		if (!file_name)
	goto out_unlock;		goto out;

	dso = __machine__addnew_vdso(machine, vdso_file->dso_name, file_name);		dso = __machine__addnew_vdso(machine, vdso_file->dso_name, file_name);
	out_unlock:		out:
	pthread_rwlock_unlock(&machine->dsos.lock);
	return dso;		return dso;
	}		}

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