[tip: perf/urgent] perf parse: Copy string to perf_evsel_config_term

From: tip-bot2 for Leo Yan
Date: Wed Feb 05 2020 - 10:45:27 EST


The following commit has been merged into the perf/urgent branch of tip:

Commit-ID: 3220fb8d5e59d7a9b59d02965d4209aef7691e9f
Gitweb: https://git.kernel.org/tip/3220fb8d5e59d7a9b59d02965d4209aef7691e9f
Author: Leo Yan <leo.yan@xxxxxxxxxx>
AuthorDate: Fri, 17 Jan 2020 13:52:51 +08:00
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitterDate: Thu, 30 Jan 2020 11:55:02 +01:00

perf parse: Copy string to perf_evsel_config_term

perf with CoreSight fails to record trace data with command:

perf record -e cs_etm/@tmc_etr0/u --per-thread ls
failed to set sink "" on event cs_etm/@tmc_etr0/u with 21 (Is a
directory)/perf/

This failure is root caused with the commit 1dc925568f01 ("perf
parse: Add a deep delete for parse event terms").

The log shows, cs_etm fails to parse the sink attribution; cs_etm event
relies on the event configuration to pass sink name, but the event
specific configuration data cannot be passed properly with flow:

get_config_terms()
ADD_CONFIG_TERM(DRV_CFG, term->val.str);
__t->val.str = term->val.str;
`> __t->val.str is assigned to term->val.str;

parse_events_terms__purge()
parse_events_term__delete()
zfree(&term->val.str);
`> term->val.str is freed and assigned to NULL pointer;

cs_etm_set_sink_attr()
sink = __t->val.str;
`> sink string has been freed.

To fix this issue, in the function get_config_terms(), this patch
changes to use strdup() for allocation a new duplicate string rather
than directly assignment string pointer.

This patch addes a new field 'free_str' in the data structure
perf_evsel_config_term; 'free_str' is set to true when the union is used
as a string pointer; thus it can tell perf_evsel__free_config_terms() to
free the string.

Fixes: 1dc925568f01 ("perf parse: Add a deep delete for parse event terms")
Suggested-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Signed-off-by: Leo Yan <leo.yan@xxxxxxxxxx>
Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Ian Rogers <irogers@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
Cc: Mike Leach <mike.leach@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Suzuki Poulouse <suzuki.poulose@xxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Link: http://lore.kernel.org/lkml/20200117055251.24058-2-leo.yan@xxxxxxxxxx
[ Use zfree() in perf_evsel__free_config_terms ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>

:# modified: tools/perf/util/evsel_config.h
---
tools/perf/util/evsel.c | 2 ++
tools/perf/util/evsel_config.h | 1 +
tools/perf/util/parse-events.c | 7 ++++++-
3 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 549abd4..c8dc445 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -1265,6 +1265,8 @@ static void perf_evsel__free_config_terms(struct evsel *evsel)

list_for_each_entry_safe(term, h, &evsel->config_terms, list) {
list_del_init(&term->list);
+ if (term->free_str)
+ zfree(&term->val.str);
free(term);
}
}
diff --git a/tools/perf/util/evsel_config.h b/tools/perf/util/evsel_config.h
index b4a6520..e026ab6 100644
--- a/tools/perf/util/evsel_config.h
+++ b/tools/perf/util/evsel_config.h
@@ -32,6 +32,7 @@ enum evsel_term_type {
struct perf_evsel_config_term {
struct list_head list;
enum evsel_term_type type;
+ bool free_str;
union {
u64 period;
u64 freq;
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index f59f3c8..c01ba6f 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -1240,7 +1240,12 @@ do { \
#define ADD_CONFIG_TERM_STR(__type, __val) \
do { \
ADD_CONFIG_TERM(__type); \
- __t->val.str = __val; \
+ __t->val.str = strdup(__val); \
+ if (!__t->val.str) { \
+ zfree(&__t); \
+ return -ENOMEM; \
+ } \
+ __t->free_str = true; \
} while (0)

struct parse_events_term *term;