gem_mmap_gtt: Test mmaping less than the full object

A bug was recently introduced into the kernel that happened when the vma
was smaller than the object. Test that.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

diff --git a/tests/gem_mmap_gtt.c b/tests/gem_mmap_gtt.c
index c315470..6fad80a 100644 (file)
--- a/tests/gem_mmap_gtt.c
+++ b/tests/gem_mmap_gtt.c
@@ -112,6 +112,40 @@ test_access(int fd)
 }
 
 static void
+test_short(int fd)
+{
+       struct drm_i915_gem_mmap_gtt mmap_arg;
+       int pages, p;
+
+       mmap_arg.handle = gem_create(fd, OBJECT_SIZE);
+       igt_assert(mmap_arg.handle);
+
+       igt_assert(drmIoctl(fd,
+                           DRM_IOCTL_I915_GEM_MMAP_GTT,
+                           &mmap_arg) == 0);
+       for (pages = 1; pages <= OBJECT_SIZE / 4096; pages <<= 1) {
+               uint8_t *r, *w;
+
+               w = mmap64(0, pages * 4096, PROT_READ | PROT_WRITE,
+                          MAP_SHARED, fd, mmap_arg.offset);
+               igt_assert(w != MAP_FAILED);
+
+               r = mmap64(0, pages * 4096, PROT_READ,
+                          MAP_SHARED, fd, mmap_arg.offset);
+               igt_assert(r != MAP_FAILED);
+
+               for (p = 0; p < pages; p++) {
+                       w[4096*p] = r[4096*p];
+                       w[4096*p+4095] = r[4096*p+4095];
+               }
+
+               munmap(r, pages * 4096);
+               munmap(w, pages * 4096);
+       }
+       gem_close(fd, mmap_arg.handle);
+}
+
+static void
 test_copy(int fd)
 {
        void *src, *dst;
@@ -308,6 +342,8 @@ igt_main
 
        igt_subtest("access")
                test_access(fd);
+       igt_subtest("short")
+               test_short(fd);
        igt_subtest("copy")
                test_copy(fd);
        igt_subtest("read")