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/* try and provoke a race between gem flink and close */
/* create a GEM object -
flink the object.
have two threads, a) closing the object,
b) flinking the object, then trying to open it
if the flink succeeds but the open fails then I believe we have hit the
race as got a global name back for the object that no longer existed.
For me this only really fails once in 100,000 or so runs or less,
so this acts more like a demonstration of the race than a useful test.
*/
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <assert.h>
#include <fcntl.h>
#include <inttypes.h>
#include <errno.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <pthread.h>
#include "drm.h"
#include "drmtest.h"
int fd1;
static void *
worker_thread (void *_arg)
{
int handle = *(int *)_arg;
struct drm_gem_flink flink;
struct drm_gem_open gem_open;
int ret;
flink.handle = handle;
ret = ioctl(fd1, DRM_IOCTL_GEM_FLINK, &flink);
if (ret)
return NULL;
gem_open.name = flink.name;
ret = ioctl(fd1, DRM_IOCTL_GEM_OPEN, &gem_open);
if (ret) {
fprintf(stderr,"open ret for name %d is %d %d\n", gem_open.name, ret, errno);
return (void *)1;
}
gem_close(fd1, gem_open.handle);
return NULL;
}
int main(int argc, char **argv)
{
int i;
uint32_t handle;
int ret;
pthread_t flinker;
struct drm_gem_flink flink;
struct drm_gem_open gem_open;
int name1, name2;
void *retval;
fd1 = drm_open_any();
for (i = 0; i < 100000; i++) {
handle = gem_create(fd1, 4096);
flink.handle = handle;
ret = ioctl(fd1, DRM_IOCTL_GEM_FLINK, &flink);
assert(ret == 0);
pthread_create(&flinker, NULL, worker_thread, &handle);
gem_close(fd1, handle);
pthread_join(flinker, &retval);
if (retval != NULL)
fprintf(stderr,"triggered race on round %d\n", i);
}
close(fd1);
}
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