[igt-dev] [PATCH i-g-t 4/8] i915/gem_create: Verify that all new objects are clear

Chris Wilson
2019-02-17T14:35:52Z

The kernel must not return stale information back to userspace when they
create a new object. For that purpose, we always clear objects on
creation, so verify that this is so.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
---
tests/i915/gem_create.c | 71 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 71 insertions(+)

diff --git a/tests/i915/gem_create.c b/tests/i915/gem_create.c
index 25c5e8088..9de2263d5 100644
--- a/tests/i915/gem_create.c
+++ b/tests/i915/gem_create.c
@@ -44,6 +44,7 @@
#include <sys/stat.h>
#include <sys/time.h>
#include <getopt.h>
+#include <pthread.h>

#include <drm.h>

@@ -141,6 +142,73 @@ static void invalid_nonaligned_size(int fd)
gem_close(fd, handle);
}

+static uint64_t get_npages(uint64_t *global, uint64_t npages)
+{
+ uint64_t try, old, max;
+
+ max = *global;
+ do {
+ old = max;
+ try = npages % (max / 2);
+ max -= try;
+ } while ((max = __sync_val_compare_and_swap(global, old, max)) != old);
+
+ return try;
+}
+
+struct thread_clear {
+ uint64_t max;
+ int timeout;
+ int i915;
+};
+
+static void *thread_clear(void *data)
+{
+ struct thread_clear *arg = data;
+ int i915 = arg->i915;
+
+ igt_until_timeout(arg->timeout) {
+ uint32_t handle;
+ uint64_t npages;
+
+ npages = random();
+ npages <<= 32;
+ npages |= random();
+ npages = get_npages(&arg->max, npages);
+
+ handle = gem_create(i915, npages << 12);
+ for (uint64_t page = 0; page < npages; page++) {
+ uint64_t x;
+
+ gem_read(i915, handle,
+ page % (4096 - sizeof(x)),
+ &x, sizeof(x));
+ igt_assert_eq_u64(x, 0);
+ }
+ gem_close(i915, handle);
+
+ __sync_add_and_fetch(&arg->max, npages);
+ }
+
+ return NULL;
+}
+
+static void always_clear(int i915, int timeout)
+{
+ struct thread_clear arg = {
+ .i915 = i915,
+ .timeout = timeout,
+ .max = intel_get_avail_ram_mb() << (20 - 12), /* in pages */
+ };
+ const int ncpus = sysconf(_SC_NPROCESSORS_ONLN);
+ pthread_t thread[ncpus];
+
+ for (int i = 0; i < ncpus; i++)
+ pthread_create(&thread[i], NULL, thread_clear, &arg);
+ for (int i = 0; i < ncpus; i++)
+ pthread_join(thread[i], NULL);
+}
+
igt_main
{
int fd = -1;
@@ -162,4 +230,7 @@ igt_main

igt_subtest("create-invalid-nonaligned")
invalid_nonaligned_size(fd);
+
+ igt_subtest("create-clear")
+ always_clear(fd, 30);
}
--
2.20.1