• Leo Yan's avatar
    perf parse: Copy string to perf_evsel_config_term · 3220fb8d
    Leo Yan authored
    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 1dc92556 ("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: 1dc92556 ("perf parse: Add a deep delete for parse event terms")
    Suggested-by: default avatarJiri Olsa <jolsa@kernel.org>
    Signed-off-by: default avatarLeo Yan <leo.yan@linaro.org>
    Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
    Cc: Adrian Hunter <adrian.hunter@intel.com>
    Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
    Cc: Andi Kleen <ak@linux.intel.com>
    Cc: Ian Rogers <irogers@google.com>
    Cc: Mark Rutland <mark.rutland@arm.com>
    Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
    Cc: Mike Leach <mike.leach@linaro.org>
    Cc: Namhyung Kim <namhyung@kernel.org>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
    Cc: linux-arm-kernel@lists.infradead.org
    Link: http://lore.kernel.org/lkml/20200117055251.24058-2-leo.yan@linaro.org
    [ Use zfree() in perf_evsel__free_config_terms ]
    Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
    
    :#	modified:   tools/perf/util/evsel_config.h
    3220fb8d
evsel.c 65.1 KB