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bp_signal_overflow.c 2.69 KiB
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  • /*
     * Originally done by Vince Weaver <vincent.weaver@maine.edu> for
     * perf_event_tests (git://github.com/deater/perf_event_tests)
     */
    
    
    /*
     * Powerpc needs __SANE_USERSPACE_TYPES__ before <linux/types.h> to select
     * 'int-ll64.h' and avoid compile warnings when printing __u64 with %llu.
     */
    #define __SANE_USERSPACE_TYPES__
    
    
    #include <stdlib.h>
    #include <stdio.h>
    #include <unistd.h>
    #include <string.h>
    #include <sys/ioctl.h>
    #include <time.h>
    #include <fcntl.h>
    #include <signal.h>
    #include <sys/mman.h>
    #include <linux/compiler.h>
    #include <linux/hw_breakpoint.h>
    
    #include "tests.h"
    #include "debug.h"
    #include "perf.h"
    
    static int overflows;
    
    __attribute__ ((noinline))
    static int test_function(void)
    {
    	return time(NULL);
    }
    
    static void sig_handler(int signum __maybe_unused,
    			siginfo_t *oh __maybe_unused,
    			void *uc __maybe_unused)
    {
    	overflows++;
    }
    
    static long long bp_count(int fd)
    {
    	long long count;
    	int ret;
    
    	ret = read(fd, &count, sizeof(long long));
    	if (ret != sizeof(long long)) {
    		pr_debug("failed to read: %d\n", ret);
    		return TEST_FAIL;
    	}
    
    	return count;
    }
    
    #define EXECUTIONS 10000
    #define THRESHOLD  100
    
    int test__bp_signal_overflow(void)
    {
    	struct perf_event_attr pe;
    	struct sigaction sa;
    	long long count;
    	int fd, i, fails = 0;
    
    	/* setup SIGIO signal handler */
    	memset(&sa, 0, sizeof(struct sigaction));
    	sa.sa_sigaction = (void *) sig_handler;
    	sa.sa_flags = SA_SIGINFO;
    
    	if (sigaction(SIGIO, &sa, NULL) < 0) {
    		pr_debug("failed setting up signal handler\n");
    		return TEST_FAIL;
    	}
    
    	memset(&pe, 0, sizeof(struct perf_event_attr));
    	pe.type = PERF_TYPE_BREAKPOINT;
    	pe.size = sizeof(struct perf_event_attr);
    
    	pe.config = 0;
    	pe.bp_type = HW_BREAKPOINT_X;
    	pe.bp_addr = (unsigned long) test_function;
    	pe.bp_len = sizeof(long);
    
    	pe.sample_period = THRESHOLD;
    	pe.sample_type = PERF_SAMPLE_IP;
    	pe.wakeup_events = 1;
    
    	pe.disabled = 1;
    	pe.exclude_kernel = 1;
    	pe.exclude_hv = 1;
    
    	fd = sys_perf_event_open(&pe, 0, -1, -1, 0);
    	if (fd < 0) {
    		pr_debug("failed opening event %llx\n", pe.config);
    		return TEST_FAIL;
    	}
    
    	fcntl(fd, F_SETFL, O_RDWR|O_NONBLOCK|O_ASYNC);
    	fcntl(fd, F_SETSIG, SIGIO);
    	fcntl(fd, F_SETOWN, getpid());
    
    	ioctl(fd, PERF_EVENT_IOC_RESET, 0);
    	ioctl(fd, PERF_EVENT_IOC_ENABLE, 0);
    
    	for (i = 0; i < EXECUTIONS; i++)
    		test_function();
    
    	ioctl(fd, PERF_EVENT_IOC_DISABLE, 0);
    
    	count = bp_count(fd);
    
    	close(fd);
    
    	pr_debug("count %lld, overflow %d\n",
    		 count, overflows);
    
    	if (count != EXECUTIONS) {
    		pr_debug("\tWrong number of executions %lld != %d\n",
    		count, EXECUTIONS);
    		fails++;
    	}
    
    	if (overflows != EXECUTIONS / THRESHOLD) {
    		pr_debug("\tWrong number of overflows %d != %d\n",
    		overflows, EXECUTIONS / THRESHOLD);
    		fails++;
    	}
    
    	return fails ? TEST_FAIL : TEST_OK;
    }