On 32-bits platform with more than 32 registers, the 64 bits mask is truncate to the lower 32 bits and the return value of hweight_long will always smaller than 32. When kernel outputs more than 32 registers, but the user perf program only counts 32, there will be a data mismatch result to overflow check fail.
CC: Peter Zijlstra <[email protected]> CC: Ingo Molnar <[email protected]> CC: Arnaldo Carvalho de Melo <[email protected]> CC: Alexander Shishkin <[email protected]> CC: Jiri Olsa <[email protected]> CC: Namhyung Kim <[email protected]> CC: Guo Ren <[email protected]> Signed-off-by: Mao Han <[email protected]> --- tools/perf/util/evsel.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index 7835e05..73c78be 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -2322,7 +2322,7 @@ int perf_evsel__parse_sample(struct perf_evsel *evsel, union perf_event *event, if (data->user_regs.abi) { u64 mask = evsel->attr.sample_regs_user; - sz = hweight_long(mask) * sizeof(u64); + sz = hweight64(mask) * sizeof(u64); OVERFLOW_CHECK(array, sz, max_size); data->user_regs.mask = mask; data->user_regs.regs = (u64 *)array; -- 2.7.4
