diff options
| author | Krister Johansen <kjlx@templeofstupid.com> | 2017-01-05 22:23:31 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-03-12 06:41:47 +0100 |
| commit | 11a4d644d6d84a34a393a389d5efd4e036b04a62 (patch) | |
| tree | 793dc6c63b83a7b774bed66aeb6858586d4c4cb7 /tools/perf/util/callchain.c | |
| parent | 65013a93b6c335bd166c911d73c47ff4bcbdb8be (diff) | |
perf callchain: Reference count maps
commit aa33b9b9a2ebb00d33c83a5312d4fbf2d5aeba36 upstream.
If dso__load_kcore frees all of the existing maps, but one has already
been attached to a callchain cursor node, then we can get a SIGSEGV in
any function that happens to try to use this invalid cursor. Use the
existing map refcount mechanism to forestall cleanup of a map until the
cursor iterates past the node.
Signed-off-by: Krister Johansen <kjlx@templeofstupid.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Fixes: 84c2cafa2889 ("perf tools: Reference count struct map")
Link: http://lkml.kernel.org/r/20170106062331.GB2707@templeofstupid.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'tools/perf/util/callchain.c')
| -rw-r--r-- | tools/perf/util/callchain.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c index ae58b493af45..ecf6236f3b5f 100644 --- a/tools/perf/util/callchain.c +++ b/tools/perf/util/callchain.c @@ -437,7 +437,7 @@ fill_node(struct callchain_node *node, struct callchain_cursor *cursor) } call->ip = cursor_node->ip; call->ms.sym = cursor_node->sym; - call->ms.map = cursor_node->map; + call->ms.map = map__get(cursor_node->map); list_add_tail(&call->list, &node->val); callchain_cursor_advance(cursor); @@ -462,6 +462,7 @@ add_child(struct callchain_node *parent, list_for_each_entry_safe(call, tmp, &new->val, list) { list_del(&call->list); + map__zput(call->ms.map); free(call); } free(new); @@ -730,6 +731,7 @@ merge_chain_branch(struct callchain_cursor *cursor, callchain_cursor_append(cursor, list->ip, list->ms.map, list->ms.sym); list_del(&list->list); + map__zput(list->ms.map); free(list); } @@ -778,7 +780,8 @@ int callchain_cursor_append(struct callchain_cursor *cursor, } node->ip = ip; - node->map = map; + map__zput(node->map); + node->map = map__get(map); node->sym = sym; cursor->nr++; @@ -945,11 +948,13 @@ static void free_callchain_node(struct callchain_node *node) list_for_each_entry_safe(list, tmp, &node->parent_val, list) { list_del(&list->list); + map__zput(list->ms.map); free(list); } list_for_each_entry_safe(list, tmp, &node->val, list) { list_del(&list->list); + map__zput(list->ms.map); free(list); } @@ -1013,6 +1018,7 @@ int callchain_node__make_parent_list(struct callchain_node *node) goto out; *new = *chain; new->has_children = false; + map__get(new->ms.map); list_add_tail(&new->list, &head); } parent = parent->parent; @@ -1033,6 +1039,7 @@ int callchain_node__make_parent_list(struct callchain_node *node) out: list_for_each_entry_safe(chain, new, &head, list) { list_del(&chain->list); + map__zput(chain->ms.map); free(chain); } return -ENOMEM; |