Hi, This patch fixes a real crash problem when we do 'perf report' on an arm64 platform with arm32 program. It is introduced by commit f9b2bdf228 ("perf tools: Find vdso with the consider of cross-platform"). From dmesg report, perf crashes in dso__type() because dso is NULL.
Still don't know why on x86 it never crash, but it is obviously that we need to check the return vaule from __dso__find(): it can be NULL. So please consider pulling. Thank you. On 2016/6/22 14:57, He Kuang wrote:
We should check if 'dso' is a null pointer before passing it to the function dso__type(), otherwise a segfault will be raised in dso__data_get_fd(). In function machine__find_vdso(), the return value checking of 'dso' is missed and this patch fixes this issue. Signed-off-by: He Kuang <heku...@huawei.com> --- tools/perf/util/vdso.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/perf/util/vdso.c b/tools/perf/util/vdso.c index 8f81c41..7bdcad4 100644 --- a/tools/perf/util/vdso.c +++ b/tools/perf/util/vdso.c @@ -296,7 +296,7 @@ static struct dso *machine__find_vdso(struct machine *machine, if (!dso) { dso = __dsos__find(&machine->dsos, DSO__NAME_VDSO, true); - if (dso_type != dso__type(dso, machine)) + if (dso && dso_type != dso__type(dso, machine)) dso = NULL; } break;