| From d7d0fbe5603fdb582abdc2d2196b246af11c5da4 Mon Sep 17 00:00:00 2001 |
| From: Krister Johansen <kjlx@templeofstupid.com> |
| Date: Thu, 5 Jan 2017 22:23:31 -0800 |
| Subject: [PATCH] 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> |
| Cc: stable@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: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| 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; |
| diff --git a/tools/perf/util/callchain.h b/tools/perf/util/callchain.h |
| index 47cfd1080975..b7cbabb3931f 100644 |
| --- a/tools/perf/util/callchain.h |
| +++ b/tools/perf/util/callchain.h |
| @@ -5,6 +5,7 @@ |
| #include <linux/list.h> |
| #include <linux/rbtree.h> |
| #include "event.h" |
| +#include "map.h" |
| #include "symbol.h" |
| |
| #define HELP_PAD "\t\t\t\t" |
| @@ -174,8 +175,13 @@ int callchain_merge(struct callchain_cursor *cursor, |
| */ |
| static inline void callchain_cursor_reset(struct callchain_cursor *cursor) |
| { |
| + struct callchain_cursor_node *node; |
| + |
| cursor->nr = 0; |
| cursor->last = &cursor->first; |
| + |
| + for (node = cursor->first; node != NULL; node = node->next) |
| + map__zput(node->map); |
| } |
| |
| int callchain_cursor_append(struct callchain_cursor *cursor, u64 ip, |
| diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c |
| index 7214913861cf..1f6d89af7665 100644 |
| --- a/tools/perf/util/hist.c |
| +++ b/tools/perf/util/hist.c |
| @@ -1,6 +1,7 @@ |
| #include "util.h" |
| #include "build-id.h" |
| #include "hist.h" |
| +#include "map.h" |
| #include "session.h" |
| #include "sort.h" |
| #include "evlist.h" |
| @@ -1015,6 +1016,10 @@ int hist_entry_iter__add(struct hist_entry_iter *iter, struct addr_location *al, |
| int max_stack_depth, void *arg) |
| { |
| int err, err2; |
| + struct map *alm = NULL; |
| + |
| + if (al && al->map) |
| + alm = map__get(al->map); |
| |
| err = sample__resolve_callchain(iter->sample, &callchain_cursor, &iter->parent, |
| iter->evsel, al, max_stack_depth); |
| @@ -1054,6 +1059,8 @@ out: |
| if (!err) |
| err = err2; |
| |
| + map__put(alm); |
| + |
| return err; |
| } |
| |
| -- |
| 2.12.0 |
| |