cregit-Linux how code gets into the kernel

Release 4.11 tools/testing/selftests/powerpc/pmu/ebb/ebb_on_child_test.c

/*
 * Copyright 2014, Michael Ellerman, IBM Corp.
 * Licensed under GPLv2.
 */

#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. Nothing interesting happens, because
 * even though the event is enabled and running the child hasn't enabled the
 * actual delivery of the EBBs.
 */


static int victim_child(union pipe read_pipe, union pipe write_pipe) { int i; FAIL_IF(wait_for_parent(read_pipe)); FAIL_IF(notify_parent(write_pipe)); /* Parent creates EBB event */ FAIL_IF(wait_for_parent(read_pipe)); FAIL_IF(notify_parent(write_pipe)); /* Check the EBB is enabled by writing PMC1 */ write_pmc1(); /* EBB event is enabled here */ for (i = 0; i < 1000000; i++) ; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Michael Ellerman72100.00%1100.00%
Total72100.00%1100.00%


int ebb_on_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)); } 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)); FAIL_IF(sync_with_child(read_pipe, write_pipe)); /* Child should just exit happily */ FAIL_IF(wait_for_child(pid)); event_close(&event); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Michael Ellerman16996.02%150.00%
Denis Kirjanov73.98%150.00%
Total176100.00%2100.00%


int main(void) { return test_harness(ebb_on_child, "ebb_on_child"); }

Contributors

PersonTokensPropCommitsCommitProp
Michael Ellerman15100.00%1100.00%
Total15100.00%1100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Michael Ellerman28297.58%150.00%
Denis Kirjanov72.42%150.00%
Total289100.00%2100.00%
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