// SPDX-License-Identifier: GPL-2.0-only /* * Copyright 2014, Michael Ellerman, IBM Corp. */ #include <signal.h> #include <stdio.h> #include <stdlib.h> #include <stdbool.h> #include <sys/types.h> #include <sys/wait.h> #include <unistd.h> #include "ebb.h" /* * Tests we can setup an EBB on our child. The child expects this and enables * EBBs, which are then delivered to the child, even though the event is * created by the parent. */ static int victim_child(union pipe read_pipe, union pipe write_pipe) { FAIL_IF(wait_for_parent(read_pipe)); /* Setup our EBB handler, before the EBB event is created */ ebb_enable_pmc_counting(1); setup_ebb_handler(standard_ebb_callee); ebb_global_enable(); FAIL_IF(notify_parent(write_pipe)); while (ebb_state.stats.ebb_count < 20) { FAIL_IF(core_busy_loop()); } ebb_global_disable(); ebb_freeze_pmcs(); count_pmc(1, sample_period); dump_ebb_state(); FAIL_IF(ebb_state.stats.ebb_count == 0); return 0; } /* Tests we can setup an EBB on our child - if it's expecting it */ int ebb_on_willing_child(void) { union pipe read_pipe, write_pipe; struct event event; pid_t pid; SKIP_IF(!ebb_is_supported()); FAIL_IF(pipe(read_pipe.fds) == -1); FAIL_IF(pipe(write_pipe.fds) == -1); pid = fork(); if (pid == 0) { /* NB order of pipes looks reversed */ exit(victim_child(write_pipe, read_pipe)); } /* Signal the child to setup its EBB handler */ FAIL_IF(sync_with_child(read_pipe, write_pipe)); /* Child is running now */ event_init_named(&event, 0x1001e, "cycles"); event_leader_ebb_init(&event); event.attr.exclude_kernel = 1; event.attr.exclude_hv = 1; event.attr.exclude_idle = 1; FAIL_IF(event_open_with_pid(&event, pid)); FAIL_IF(ebb_event_enable(&event)); /* Child show now take EBBs and then exit */ FAIL_IF(wait_for_child(pid)); event_close(&event); return 0; } int main(void) { return test_harness(ebb_on_willing_child, "ebb_on_willing_child"); }