From: Arnaldo Carvalho de Melo <a...@redhat.com>
A segfault happens on 'perf test hists_link' because we end up using a
struct machines on the stack, and then machines__init() was not
initializing the newly introduced rb_root, just the existing list_head.
When we introduced struct dsos, to group the two ways to store dsos,
i.e. the linked list and the rbtree, we didn't turned the initialization
done in:
machines__init(machines->host) ->
machine__init() ->
INIT_LIST_HEAD
into a dsos__init() to keep on initializing the list_head but _as well_
initializing the rb_root, oops.
All worked because outside perf-test we probably zalloc the whole thing
which ends up initializing it in to NULL.
So the problem looks contained to 'perf test' that uses it on stack,
etc.
Reported-by: Jiri Olsa <jo...@redhat.com>
Acked-by: Waiman Long <waiman.l...@hp.com>,
Cc: Adrian Hunter <adrian.hun...@intel.com>,
Cc: Don Zickus <dzic...@redhat.com>
Cc: Douglas Hatch <doug.ha...@hp.com>
Cc: Ingo Molnar <mi...@redhat.com>
Cc: Jiri Olsa <jo...@kernel.org>
Cc: Namhyung Kim <namhy...@kernel.org>
Cc: Paul Mackerras <pau...@samba.org>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Scott J Norton <scott.nor...@hp.com>
Cc: Waiman Long <waiman.l...@hp.com>,
Link: http://lkml.kernel.org/r/20141014180353.gf3...@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com>
---
tools/perf/util/machine.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index b7d477fbda02..34fc7c8672e4 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -13,12 +13,18 @@
#include <symbol/kallsyms.h>
#include "unwind.h"
+static void dsos__init(struct dsos *dsos)
+{
+ INIT_LIST_HEAD(&dsos->head);
+ dsos->root = RB_ROOT;
+}
+
int machine__init(struct machine *machine, const char *root_dir, pid_t pid)
{
map_groups__init(&machine->kmaps);
RB_CLEAR_NODE(&machine->rb_node);
- INIT_LIST_HEAD(&machine->user_dsos.head);
- INIT_LIST_HEAD(&machine->kernel_dsos.head);
+ dsos__init(&machine->user_dsos);
+ dsos__init(&machine->kernel_dsos);
machine->threads = RB_ROOT;
INIT_LIST_HEAD(&machine->dead_threads);
--
1.9.3
--
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