--- /dev/null
+/*
+ * Copyright © 2015-2018 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#undef _FILE_OFFSET_BITS /* prevent #define open open64 */
+
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdarg.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <sys/sysmacros.h>
+#include <dlfcn.h>
+#include <pthread.h>
+#include <i915_drm.h>
+
+#include "util/hash_table.h"
+
+#define INTEL_LOG_TAG "INTEL-SANITIZE-GPU"
+#include "common/intel_log.h"
+#include "common/gen_clflush.h"
+
+static int (*libc_open)(const char *pathname, int flags, mode_t mode);
+static int (*libc_close)(int fd);
+static int (*libc_ioctl)(int fd, unsigned long request, void *argp);
+static int (*libc_fcntl)(int fd, int cmd, int param);
+
+#define DRM_MAJOR 226
+
+/* TODO: we want to make sure that the padding forces
+ * the BO to take another page on the (PP)GTT; 4KB
+ * may or may not be the page size for the BO. Indeed,
+ * depending on GPU, kernel version and GEM size, the
+ * page size can be one of 4KB, 64KB or 2M.
+ */
+#define PADDING_SIZE 4096
+
+struct refcnt_hash_table {
+ struct hash_table *t;
+ int refcnt;
+};
+
+pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
+#define MUTEX_LOCK() do { \
+ if (unlikely(pthread_mutex_lock(&mutex))) { \
+ intel_loge("mutex_lock failed"); \
+ abort(); \
+ } \
+} while (0)
+#define MUTEX_UNLOCK() do { \
+ if (unlikely(pthread_mutex_unlock(&mutex))) { \
+ intel_loge("mutex_unlock failed"); \
+ abort(); \
+ } \
+} while (0)
+
+static struct hash_table *fds_to_bo_sizes = NULL;
+
+static inline struct hash_table*
+bo_size_table(int fd)
+{
+ struct hash_entry *e = _mesa_hash_table_search(fds_to_bo_sizes,
+ (void*)(uintptr_t)fd);
+ return e ? ((struct refcnt_hash_table*)e->data)->t : NULL;
+}
+
+static inline uint64_t
+bo_size(int fd, uint32_t handle)
+{
+ struct hash_table *t = bo_size_table(fd);
+ if (!t)
+ return UINT64_MAX;
+ struct hash_entry *e = _mesa_hash_table_search(t, (void*)(uintptr_t)handle);
+ return e ? (uint64_t)e->data : UINT64_MAX;
+}
+
+static inline bool
+is_drm_fd(int fd)
+{
+ return !!bo_size_table(fd);
+}
+
+static inline void
+add_drm_fd(int fd)
+{
+ struct refcnt_hash_table *r = malloc(sizeof(*r));
+ r->refcnt = 1;
+ r->t = _mesa_hash_table_create(NULL, _mesa_hash_pointer,
+ _mesa_key_pointer_equal);
+ _mesa_hash_table_insert(fds_to_bo_sizes, (void*)(uintptr_t)fd,
+ (void*)(uintptr_t)r);
+}
+
+static inline void
+dup_drm_fd(int old_fd, int new_fd)
+{
+ struct hash_entry *e = _mesa_hash_table_search(fds_to_bo_sizes,
+ (void*)(uintptr_t)old_fd);
+ struct refcnt_hash_table *r = e->data;
+ r->refcnt++;
+ _mesa_hash_table_insert(fds_to_bo_sizes, (void*)(uintptr_t)new_fd,
+ (void*)(uintptr_t)r);
+}
+
+static inline void
+del_drm_fd(int fd)
+{
+ struct hash_entry *e = _mesa_hash_table_search(fds_to_bo_sizes,
+ (void*)(uintptr_t)fd);
+ struct refcnt_hash_table *r = e->data;
+ if (!--r->refcnt) {
+ _mesa_hash_table_remove(fds_to_bo_sizes, e);
+ _mesa_hash_table_destroy(r->t, NULL);
+ free(r);
+ }
+}
+
+/* Our goal is not to have noise good enough for cryto,
+ * but instead values that are unique-ish enough that
+ * it is incredibly unlikely that a buffer overwrite
+ * will produce the exact same values.
+ */
+static uint8_t
+next_noise_value(uint8_t prev_noise)
+{
+ uint32_t v = prev_noise;
+ return (v * 103u + 227u) & 0xFF;
+}
+
+static void
+fill_noise_buffer(uint8_t *dst, uint8_t start, uint32_t length)
+{
+ for(uint32_t i = 0; i < length; ++i) {
+ dst[i] = start;
+ start = next_noise_value(start);
+ }
+}
+
+static bool
+padding_is_good(int fd, uint32_t handle)
+{
+ struct drm_i915_gem_mmap mmap_arg = {
+ .handle = handle,
+ .offset = bo_size(fd, handle),
+ .size = PADDING_SIZE,
+ .flags = 0,
+ };
+
+ /* Unknown bo, maybe prime or userptr. Ignore */
+ if (mmap_arg.offset == UINT64_MAX)
+ return true;
+
+ uint8_t *mapped;
+ int ret;
+ uint8_t expected_value;
+
+ ret = libc_ioctl(fd, DRM_IOCTL_I915_GEM_MMAP, &mmap_arg);
+ if (ret != 0) {
+ intel_logd("Unable to map buffer %d for pad checking.", handle);
+ return false;
+ }
+
+ mapped = (uint8_t*) (uintptr_t) mmap_arg.addr_ptr;
+ /* bah-humbug, we need to see the latest contents and
+ * if the bo is not cache coherent we likely need to
+ * invalidate the cache lines to get it.
+ */
+ gen_invalidate_range(mapped, PADDING_SIZE);
+
+ expected_value = handle & 0xFF;
+ for (uint32_t i = 0; i < PADDING_SIZE; ++i) {
+ if (expected_value != mapped[i]) {
+ munmap(mapped, PADDING_SIZE);
+ return false;
+ }
+ expected_value = next_noise_value(expected_value);
+ }
+ munmap(mapped, PADDING_SIZE);
+
+ return true;
+}
+
+static int
+create_with_padding(int fd, struct drm_i915_gem_create *create)
+{
+ create->size += PADDING_SIZE;
+ int ret = libc_ioctl(fd, DRM_IOCTL_I915_GEM_CREATE, create);
+ create->size -= PADDING_SIZE;
+
+ if (ret != 0)
+ return ret;
+
+ uint8_t *noise_values;
+ struct drm_i915_gem_mmap mmap_arg = {
+ .handle = create->handle,
+ .offset = create->size,
+ .size = PADDING_SIZE,
+ .flags = 0,
+ };
+
+ ret = libc_ioctl(fd, DRM_IOCTL_I915_GEM_MMAP, &mmap_arg);
+ if (ret != 0)
+ return 0;
+
+ noise_values = (uint8_t*) (uintptr_t) mmap_arg.addr_ptr;
+ fill_noise_buffer(noise_values, create->handle & 0xFF,
+ PADDING_SIZE);
+ munmap(noise_values, PADDING_SIZE);
+
+ _mesa_hash_table_insert(bo_size_table(fd), (void*)(uintptr_t)create->handle,
+ (void*)(uintptr_t)create->size);
+
+ return 0;
+}
+
+static int
+exec_and_check_padding(int fd, unsigned long request,
+ struct drm_i915_gem_execbuffer2 *exec)
+{
+ int ret = libc_ioctl(fd, request, exec);
+ if (ret != 0)
+ return ret;
+
+ struct drm_i915_gem_exec_object2 *objects =
+ (void*)(uintptr_t)exec->buffers_ptr;
+ uint32_t batch_bo = exec->flags & I915_EXEC_BATCH_FIRST ? objects[0].handle :
+ objects[exec->buffer_count - 1].handle;
+
+ struct drm_i915_gem_wait wait = {
+ .bo_handle = batch_bo,
+ .timeout_ns = -1,
+ };
+ ret = libc_ioctl(fd, DRM_IOCTL_I915_GEM_WAIT, &wait);
+ if (ret != 0)
+ return ret;
+
+ bool detected_out_of_bounds_write = false;
+
+ for (int i = 0; i < exec->buffer_count; i++) {
+ uint32_t handle = objects[i].handle;
+
+ if (!padding_is_good(fd, handle)) {
+ detected_out_of_bounds_write = true;
+ intel_loge("Detected buffer out-of-bounds write in bo %d", handle);
+ }
+ }
+
+ if (unlikely(detected_out_of_bounds_write)) {
+ abort();
+ }
+
+ return 0;
+}
+
+static int
+gem_close(int fd, struct drm_gem_close *close)
+{
+ int ret = libc_ioctl(fd, DRM_IOCTL_GEM_CLOSE, close);
+ if (ret != 0)
+ return ret;
+
+ struct hash_table *t = bo_size_table(fd);
+ struct hash_entry *e =
+ _mesa_hash_table_search(t, (void*)(uintptr_t)close->handle);
+
+ if (e)
+ _mesa_hash_table_remove(t, e);
+
+ return 0;
+}
+
+static bool
+is_i915(int fd) {
+ struct stat stat;
+ if (fstat(fd, &stat))
+ return false;
+
+ if (!S_ISCHR(stat.st_mode) || major(stat.st_rdev) != DRM_MAJOR)
+ return false;
+
+ char name[5] = "";
+ drm_version_t version = {
+ .name = name,
+ .name_len = sizeof(name) - 1,
+ };
+ if (libc_ioctl(fd, DRM_IOCTL_VERSION, &version))
+ return false;
+
+ return strcmp("i915", name) == 0;
+}
+
+__attribute__ ((visibility ("default"))) int
+open(const char *path, int flags, ...)
+{
+ va_list args;
+ mode_t mode;
+
+ va_start(args, flags);
+ mode = va_arg(args, int);
+ va_end(args);
+
+ int fd = libc_open(path, flags, mode);
+
+ MUTEX_LOCK();
+
+ if (fd >= 0 && is_i915(fd))
+ add_drm_fd(fd);
+
+ MUTEX_UNLOCK();
+
+ return fd;
+}
+
+__attribute__ ((visibility ("default"), alias ("open"))) int
+open64(const char *path, int flags, ...);
+
+__attribute__ ((visibility ("default"))) int
+close(int fd)
+{
+ MUTEX_LOCK();
+
+ if (is_drm_fd(fd))
+ del_drm_fd(fd);
+
+ MUTEX_UNLOCK();
+
+ return libc_close(fd);
+}
+
+__attribute__ ((visibility ("default"))) int
+fcntl(int fd, int cmd, ...)
+{
+ va_list args;
+ int param;
+
+ va_start(args, cmd);
+ param = va_arg(args, int);
+ va_end(args);
+
+ int res = libc_fcntl(fd, cmd, param);
+
+ MUTEX_LOCK();
+
+ if (is_drm_fd(fd) && cmd == F_DUPFD_CLOEXEC)
+ dup_drm_fd(fd, res);
+
+ MUTEX_UNLOCK();
+
+ return res;
+}
+
+__attribute__ ((visibility ("default"))) int
+ioctl(int fd, unsigned long request, ...)
+{
+ int res;
+ va_list args;
+ void *argp;
+
+ MUTEX_LOCK();
+
+ va_start(args, request);
+ argp = va_arg(args, void *);
+ va_end(args);
+
+ if (_IOC_TYPE(request) == DRM_IOCTL_BASE && !is_drm_fd(fd) && is_i915(fd)) {
+ intel_loge("missed drm fd %d", fd);
+ add_drm_fd(fd);
+ }
+
+ if (is_drm_fd(fd)) {
+ switch (request) {
+ case DRM_IOCTL_GEM_CLOSE:
+ res = gem_close(fd, (struct drm_gem_close*)argp);
+ goto out;
+
+ case DRM_IOCTL_I915_GEM_CREATE:
+ res = create_with_padding(fd, (struct drm_i915_gem_create*)argp);
+ goto out;
+
+ case DRM_IOCTL_I915_GEM_EXECBUFFER2:
+ case DRM_IOCTL_I915_GEM_EXECBUFFER2_WR:
+ res = exec_and_check_padding(fd, request,
+ (struct drm_i915_gem_execbuffer2*)argp);
+ goto out;
+
+ default:
+ break;
+ }
+ }
+ res = libc_ioctl(fd, request, argp);
+
+ out:
+ MUTEX_UNLOCK();
+ return res;
+}
+
+static void __attribute__ ((constructor))
+init(void)
+{
+ fds_to_bo_sizes = _mesa_hash_table_create(NULL, _mesa_hash_pointer,
+ _mesa_key_pointer_equal);
+ libc_open = dlsym(RTLD_NEXT, "open");
+ libc_close = dlsym(RTLD_NEXT, "close");
+ libc_fcntl = dlsym(RTLD_NEXT, "fcntl");
+ libc_ioctl = dlsym(RTLD_NEXT, "ioctl");
+}