diff options
Diffstat (limited to 'tools/perf/tests/dwarf-unwind.c')
| -rw-r--r-- | tools/perf/tests/dwarf-unwind.c | 36 |
1 files changed, 34 insertions, 2 deletions
diff --git a/tools/perf/tests/dwarf-unwind.c b/tools/perf/tests/dwarf-unwind.c index ab28cca2cb9..0bf06bec68c 100644 --- a/tools/perf/tests/dwarf-unwind.c +++ b/tools/perf/tests/dwarf-unwind.c @@ -11,6 +11,9 @@ #include "thread.h" #include "callchain.h" +/* For bsearch. We try to unwind functions in shared object. */ +#include <stdlib.h> + static int mmap_handler(struct perf_tool *tool __maybe_unused, union perf_event *event, struct perf_sample *sample __maybe_unused, @@ -28,7 +31,7 @@ static int init_live_machine(struct machine *machine) mmap_handler, machine, true); } -#define MAX_STACK 6 +#define MAX_STACK 8 static int unwind_entry(struct unwind_entry *entry, void *arg) { @@ -37,6 +40,8 @@ static int unwind_entry(struct unwind_entry *entry, void *arg) static const char *funcs[MAX_STACK] = { "test__arch_unwind_sample", "unwind_thread", + "compare", + "bsearch", "krava_3", "krava_2", "krava_1", @@ -88,10 +93,37 @@ static int unwind_thread(struct thread *thread) return err; } +static int global_unwind_retval = -INT_MAX; + +__attribute__ ((noinline)) +static int compare(void *p1, void *p2) +{ + /* Any possible value should be 'thread' */ + struct thread *thread = *(struct thread **)p1; + + if (global_unwind_retval == -INT_MAX) + global_unwind_retval = unwind_thread(thread); + + return p1 - p2; +} + __attribute__ ((noinline)) static int krava_3(struct thread *thread) { - return unwind_thread(thread); + struct thread *array[2] = {thread, thread}; + void *fp = &bsearch; + /* + * make _bsearch a volatile function pointer to + * prevent potential optimization, which may expand + * bsearch and call compare directly from this function, + * instead of libc shared object. + */ + void *(*volatile _bsearch)(void *, void *, size_t, + size_t, int (*)(void *, void *)); + + _bsearch = fp; + _bsearch(array, &thread, 2, sizeof(struct thread **), compare); + return global_unwind_retval; } __attribute__ ((noinline)) |