.reg = { .offset = 1, .mask = 0x007FFFFC } ),
CMD( MI_LOAD_REGISTER_REG, SMI, !F, 0xFF, W,
.reg = { .offset = 1, .mask = 0x007FFFFC, .step = 1 } ),
+
+ /*
+ * We allow BB_START but apply further checks. We just sanitize the
+ * basic fields here.
+ */
+#define MI_BB_START_OPERAND_MASK GENMASK(SMI-1, 0)
+#define MI_BB_START_OPERAND_EXPECT (MI_BATCH_PPGTT_HSW | 1)
+ CMD( MI_BATCH_BUFFER_START_GEN8, SMI, !F, 0xFF, B,
+ .bits = {{
+ .offset = 0,
+ .mask = MI_BB_START_OPERAND_MASK,
+ .expected = MI_BB_START_OPERAND_EXPECT,
+ }}, ),
};
static const struct drm_i915_cmd_descriptor noop_desc =
return true;
}
+static int check_bbstart(const struct i915_gem_context *ctx,
+ u32 *cmd, u32 offset, u32 length,
+ u32 batch_len,
+ u64 batch_start,
+ u64 shadow_batch_start)
+{
+ u64 jump_offset, jump_target;
+ u32 target_cmd_offset, target_cmd_index;
+
+ /* For igt compatibility on older platforms */
+ if (CMDPARSER_USES_GGTT(ctx->i915)) {
+ DRM_DEBUG("CMD: Rejecting BB_START for ggtt based submission\n");
+ return -EACCES;
+ }
+
+ if (length != 3) {
+ DRM_DEBUG("CMD: Recursive BB_START with bad length(%u)\n",
+ length);
+ return -EINVAL;
+ }
+
+ jump_target = *(u64*)(cmd+1);
+ jump_offset = jump_target - batch_start;
+
+ /*
+ * Any underflow of jump_target is guaranteed to be outside the range
+ * of a u32, so >= test catches both too large and too small
+ */
+ if (jump_offset >= batch_len) {
+ DRM_DEBUG("CMD: BB_START to 0x%llx jumps out of BB\n",
+ jump_target);
+ return -EINVAL;
+ }
+
+ /*
+ * This cannot overflow a u32 because we already checked jump_offset
+ * is within the BB, and the batch_len is a u32
+ */
+ target_cmd_offset = lower_32_bits(jump_offset);
+ target_cmd_index = target_cmd_offset / sizeof(u32);
+
+ *(u64*)(cmd + 1) = shadow_batch_start + target_cmd_offset;
+
+ if (target_cmd_index == offset)
+ return 0;
+
+ if (ctx->jump_whitelist_cmds <= target_cmd_index) {
+ DRM_DEBUG("CMD: Rejecting BB_START - truncated whitelist array\n");
+ return -EINVAL;
+ } else if (!test_bit(target_cmd_index, ctx->jump_whitelist)) {
+ DRM_DEBUG("CMD: BB_START to 0x%llx not a previously executed cmd\n",
+ jump_target);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static void init_whitelist(struct i915_gem_context *ctx, u32 batch_len)
+{
+ const u32 batch_cmds = DIV_ROUND_UP(batch_len, sizeof(u32));
+ const u32 exact_size = BITS_TO_LONGS(batch_cmds);
+ u32 next_size = BITS_TO_LONGS(roundup_pow_of_two(batch_cmds));
+ unsigned long *next_whitelist;
+
+ if (CMDPARSER_USES_GGTT(ctx->i915))
+ return;
+
+ if (batch_cmds <= ctx->jump_whitelist_cmds) {
+ memset(ctx->jump_whitelist, 0, exact_size * sizeof(u32));
+ return;
+ }
+
+again:
+ next_whitelist = kcalloc(next_size, sizeof(long), GFP_KERNEL);
+ if (next_whitelist) {
+ kfree(ctx->jump_whitelist);
+ ctx->jump_whitelist = next_whitelist;
+ ctx->jump_whitelist_cmds =
+ next_size * BITS_PER_BYTE * sizeof(long);
+ return;
+ }
+
+ if (next_size > exact_size) {
+ next_size = exact_size;
+ goto again;
+ }
+
+ DRM_DEBUG("CMD: Failed to extend whitelist. BB_START may be disallowed\n");
+ memset(ctx->jump_whitelist, 0,
+ BITS_TO_LONGS(ctx->jump_whitelist_cmds) * sizeof(u32));
+
+ return;
+}
+
#define LENGTH_BIAS 2
/**
* i915_parse_cmds() - parse a submitted batch buffer for privilege violations
+ * @ctx: the context in which the batch is to execute
* @engine: the engine on which the batch is to execute
* @batch_obj: the batch buffer in question
- * @shadow_batch_obj: copy of the batch buffer in question
+ * @batch_start: Canonical base address of batch
* @batch_start_offset: byte offset in the batch at which execution starts
* @batch_len: length of the commands in batch_obj
+ * @shadow_batch_obj: copy of the batch buffer in question
+ * @shadow_batch_start: Canonical base address of shadow_batch_obj
*
* Parses the specified batch buffer looking for privilege violations as
* described in the overview.
* Return: non-zero if the parser finds violations or otherwise fails; -EACCES
* if the batch appears legal but should use hardware parsing
*/
-int intel_engine_cmd_parser(struct intel_engine_cs *engine,
+
+int intel_engine_cmd_parser(struct i915_gem_context *ctx,
+ struct intel_engine_cs *engine,
struct drm_i915_gem_object *batch_obj,
- struct drm_i915_gem_object *shadow_batch_obj,
+ u64 batch_start,
u32 batch_start_offset,
- u32 batch_len)
+ u32 batch_len,
+ struct drm_i915_gem_object *shadow_batch_obj,
+ u64 shadow_batch_start)
{
- u32 *cmd, *batch_end;
+ u32 *cmd, *batch_end, offset = 0;
struct drm_i915_cmd_descriptor default_desc = noop_desc;
const struct drm_i915_cmd_descriptor *desc = &default_desc;
bool needs_clflush_after = false;
return PTR_ERR(cmd);
}
+ init_whitelist(ctx, batch_len);
+
/*
* We use the batch length as size because the shadow object is as
* large or larger and copy_batch() will write MI_NOPs to the extra
goto err;
}
- /*
- * We don't try to handle BATCH_BUFFER_START because it adds
- * non-trivial complexity. Instead we abort the scan and return
- * and error to indicate that the batch is unsafe.
- */
- if (desc->cmd.value == MI_BATCH_BUFFER_START) {
- ret = -EACCES;
- goto err;
- }
-
if (desc->flags & CMD_DESC_FIXED)
length = desc->length.fixed;
else
goto err;
}
+ if (desc->cmd.value == MI_BATCH_BUFFER_START) {
+ ret = check_bbstart(ctx, cmd, offset, length,
+ batch_len, batch_start,
+ shadow_batch_start);
+
+ if (ret)
+ goto err;
+ break;
+ }
+
+ if (ctx->jump_whitelist_cmds > offset)
+ set_bit(offset, ctx->jump_whitelist);
+
cmd += length;
+ offset += length;
if (cmd >= batch_end) {
DRM_DEBUG_DRIVER("CMD: Got to the end of the buffer w/o a BBE cmd!\n");
ret = -EINVAL;
projects / users / hch / configfs.git / commitdiff