105 lines
No EOL
2.9 KiB
C
105 lines
No EOL
2.9 KiB
C
//Vince
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/* Error with overflows and perf::perf_count_sw_cpu_clock */
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/* This test will crash Linux 3.0.0 */
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/* compile with gcc -O2 -o oflo_sw_cpu_clock_crash oflo_sw_cpu_clock_crash.c */
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/* by Vince Weaver <vweaver1 _at_ eecs.utk.edu> */
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#define _GNU_SOURCE 1
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <fcntl.h>
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#include <linux/perf_event.h>
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#include <sys/syscall.h>
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#include <unistd.h>
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#include <asm/unistd.h>
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#include <sys/ioctl.h>
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#include <sys/mman.h>
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#include <signal.h>
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#include <sys/prctl.h>
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#define MATRIX_SIZE 512
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static double a[MATRIX_SIZE][MATRIX_SIZE];
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static double b[MATRIX_SIZE][MATRIX_SIZE];
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static double c[MATRIX_SIZE][MATRIX_SIZE];
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static void naive_matrix_multiply(int quiet) {
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double s;
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int i,j,k;
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for(i=0;i<MATRIX_SIZE;i++) {
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for(j=0;j<MATRIX_SIZE;j++) {
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a[i][j]=(double)i*(double)j;
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b[i][j]=(double)i/(double)(j+5);
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}
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}
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for(j=0;j<MATRIX_SIZE;j++) {
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for(i=0;i<MATRIX_SIZE;i++) {
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s=0;
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for(k=0;k<MATRIX_SIZE;k++) {
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s+=a[i][k]*b[k][j];
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}
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c[i][j] = s;
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}
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}
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s=0.0;
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for(i=0;i<MATRIX_SIZE;i++) {
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for(j=0;j<MATRIX_SIZE;j++) {
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s+=c[i][j];
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}
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}
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if (!quiet) printf("Matrix multiply sum: s=%lf\n",s);
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return;
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}
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static int total=0;
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void our_handler(int signum,siginfo_t *oh, void *blah) {
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int fd=oh->si_fd;
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ioctl(fd , PERF_EVENT_IOC_DISABLE,0);
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total++;
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ioctl(fd , PERF_EVENT_IOC_REFRESH,1);
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}
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int perf_event_open(struct perf_event_attr *hw_event_uptr,
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pid_t pid, int cpu, int group_fd, unsigned long flags) {
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return syscall(__NR_perf_event_open,hw_event_uptr,pid,cpu,group_fd,flags);
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}
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int main( int argc, char **argv ) {
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int fd;
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void *blargh;
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struct perf_event_attr pe;
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struct sigaction sa;
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memset(&sa, 0, sizeof(struct sigaction));
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sa.sa_sigaction=our_handler;
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sa.sa_flags=SA_SIGINFO;
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if (sigaction(SIGIO,&sa,NULL)<0) {
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fprintf(stderr,"Error setting up signal handler\n");
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exit(1);
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}
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memset(&pe,0,sizeof(struct perf_event_attr));
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pe.type=PERF_TYPE_SOFTWARE;
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pe.size=sizeof(struct perf_event_attr);
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pe.config=PERF_COUNT_SW_CPU_CLOCK;
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pe.sample_period=100000;
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pe.sample_type=PERF_SAMPLE_IP;
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pe.read_format=PERF_FORMAT_GROUP|PERF_FORMAT_ID;
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pe.disabled=1;
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pe.pinned=1;
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pe.exclude_kernel=1;
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pe.exclude_hv=1;
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pe.wakeup_events=1;
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fd=perf_event_open(&pe,0,-1,-1,0);
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if (fd<0) {
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printf("Error opening\n");
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}
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blargh=mmap(NULL,(1+2)*4096,PROT_READ|PROT_WRITE,MAP_SHARED,fd,0);
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fcntl(fd,F_SETFL,O_RDWR|O_NONBLOCK|O_ASYNC);
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fcntl(fd,F_SETSIG,SIGIO);
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fcntl(fd,F_SETOWN,getpid());
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ioctl(fd,PERF_EVENT_IOC_RESET,0);
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ioctl(fd,PERF_EVENT_IOC_ENABLE,0);
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naive_matrix_multiply(0);
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ioctl(fd,PERF_EVENT_IOC_DISABLE,0);
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munmap(blargh,(1+2)*4096);
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close(fd);
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printf("Total overflows: %d\n",total);
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return 0;
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} |