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| author | Krister Johansen <kjlx@templeofstupid.com> | 2017-01-05 22:23:31 -0800 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2017-02-02 11:39:09 -0300 |
| commit | aa33b9b9a2ebb00d33c83a5312d4fbf2d5aeba36 (patch) | |
| tree | bb0805b62c31bfee44ae018eac68214c0e40d1e1 /tools/perf/util/callchain.h | |
| parent | a1c9f97f0b64e6337d9cfcc08c134450934fdd90 (diff) | |
| download | lwn-aa33b9b9a2ebb00d33c83a5312d4fbf2d5aeba36.tar.gz lwn-aa33b9b9a2ebb00d33c83a5312d4fbf2d5aeba36.zip | |
perf callchain: Reference count maps
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>
Diffstat (limited to 'tools/perf/util/callchain.h')
| -rw-r--r-- | tools/perf/util/callchain.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/tools/perf/util/callchain.h b/tools/perf/util/callchain.h index 35c8e379530f..4f4b60f1558a 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" @@ -184,8 +185,13 @@ 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, |