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2e3649e237
Consider the following application:
#include <fcntl.h>
#include <string.h>
#include <drm/drm.h>
#include <sys/ioctl.h>
int main(void) {
int fd = open("/dev/dri/renderD128", O_RDWR);
struct drm_syncobj_create arg1;
ioctl(fd, DRM_IOCTL_SYNCOBJ_CREATE, &arg1);
struct drm_syncobj_handle arg2;
memset(&arg2, 1, sizeof(arg2)); // simulate dirty stack
arg2.handle = arg1.handle;
arg2.flags = 0;
arg2.fd = 0;
arg2.pad = 0;
// arg2.point = 0; // userspace is required to set point to 0
ioctl(fd, DRM_IOCTL_SYNCOBJ_HANDLE_TO_FD, &arg2);
}
The last ioctl returns EINVAL because args->point is not 0. However,
userspace developed against older kernel versions is not aware of the
new point field and might therefore not initialize it.
The correct check would be
if (args->flags & DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_TIMELINE)
return -EINVAL;
However, there might already be userspace that relies on this not
returning an error as long as point == 0. Therefore use the more lenient
check.
Fixes:
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History
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|---|---|---|
| .. | ||
| drm | ||
| host1x | ||
| ipu-v3 | ||
| nova-core | ||
| trace | ||
| vga | ||
| Makefile | ||