diff --git a/drivers/gpu/drm/i915/i915_cmd_parser.c b/drivers/gpu/drm/i915/i915_cmd_parser.c index d37c6d272a2e..80e7154f17c7 100644 --- a/drivers/gpu/drm/i915/i915_cmd_parser.c +++ b/drivers/gpu/drm/i915/i915_cmd_parser.c @@ -385,6 +385,17 @@ static const struct drm_i915_cmd_descriptor gen9_blt_cmds[] = { .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. + */ + CMD( MI_BATCH_BUFFER_START_GEN8, SMI, !F, 0xFF, B, + .bits = {{ + .offset = 0, + .mask = ~SMI, + .expected = (MI_BATCH_PPGTT_HSW | 1), + }}, ), }; #undef CMD @@ -1012,7 +1023,7 @@ unpin_src: return ret ? ERR_PTR(ret) : dst; } -static bool check_cmd(const struct intel_engine_cs *ring, +static int check_cmd(const struct intel_engine_cs *ring, const struct drm_i915_cmd_descriptor *desc, const u32 *cmd, u32 length, bool *oacontrol_set) @@ -1122,15 +1133,114 @@ static bool check_cmd(const struct intel_engine_cs *ring, return true; } +static int check_bbstart(struct intel_context *ctx, + u32 *cmd, u64 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 intel_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 * @ring: the ring on which the batch is to execute * @batch_obj: the batch buffer in question - * @shadow_batch_obj: copy of the batch buffer in question + * @user_batch_start: Canonical base address of original user 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. @@ -1138,13 +1248,16 @@ static bool check_cmd(const struct intel_engine_cs *ring, * Return: non-zero if the parser finds violations or otherwise fails; -EACCES * if the batch appears legal but should use hardware parsing */ -int i915_parse_cmds(struct intel_engine_cs *ring, +int i915_parse_cmds(struct intel_context *ctx, + struct intel_engine_cs *ring, struct drm_i915_gem_object *batch_obj, - struct drm_i915_gem_object *shadow_batch_obj, + u64 user_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_base, *batch_end; + u32 *cmd, *batch_base, *batch_end, offset = 0; struct drm_i915_cmd_descriptor default_desc = { 0 }; bool oacontrol_set = false; /* OACONTROL tracking. See check_cmd() */ int ret = 0; @@ -1156,6 +1269,8 @@ int i915_parse_cmds(struct intel_engine_cs *ring, return PTR_ERR(batch_base); } + 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 @@ -1179,16 +1294,6 @@ int i915_parse_cmds(struct intel_engine_cs *ring, break; } - /* - * 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; - break; - } - if (desc->flags & CMD_DESC_FIXED) length = desc->length.fixed; else @@ -1208,7 +1313,18 @@ int i915_parse_cmds(struct intel_engine_cs *ring, break; } + if (desc->cmd.value == MI_BATCH_BUFFER_START) { + ret = check_bbstart(ctx, cmd, offset, length, + batch_len, user_batch_start, + shadow_batch_start); + break; + } + + if (ctx->jump_whitelist_cmds > offset) + set_bit(offset, ctx->jump_whitelist); + cmd += length; + offset += length; } if (oacontrol_set) { diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 6064ca4aaaef..2a815dc2af91 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -891,6 +891,12 @@ struct intel_context { int pin_count; } engine[I915_NUM_RINGS]; + /* jump_whitelist: Bit array for tracking cmds during cmdparsing */ + unsigned long *jump_whitelist; + + /* jump_whitelist_cmds: No of cmd slots available */ + uint32_t jump_whitelist_cmds; + struct list_head link; }; @@ -3289,11 +3295,15 @@ int i915_cmd_parser_get_version(struct drm_i915_private *dev_priv); int i915_cmd_parser_init_ring(struct intel_engine_cs *ring); void i915_cmd_parser_fini_ring(struct intel_engine_cs *ring); bool i915_needs_cmd_parser(struct intel_engine_cs *ring); -int i915_parse_cmds(struct intel_engine_cs *ring, +int i915_parse_cmds(struct intel_context *cxt, + struct intel_engine_cs *ring, struct drm_i915_gem_object *batch_obj, - struct drm_i915_gem_object *shadow_batch_obj, + u64 user_batch_start, u32 batch_start_offset, - u32 batch_len); + u32 batch_len, + struct drm_i915_gem_object *shadow_batch_obj, + u64 shadow_batch_start); + /* i915_suspend.c */ extern int i915_save_state(struct drm_device *dev); diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c index 0433d25f9d23..20fb0ee1df4f 100644 --- a/drivers/gpu/drm/i915/i915_gem_context.c +++ b/drivers/gpu/drm/i915/i915_gem_context.c @@ -157,6 +157,8 @@ void i915_gem_context_free(struct kref *ctx_ref) if (i915.enable_execlists) intel_lr_context_free(ctx); + kfree(ctx->jump_whitelist); + /* * This context is going away and we need to remove all VMAs still * around. This is to handle imported shared objects for which @@ -246,6 +248,9 @@ __create_hw_context(struct drm_device *dev, ctx->hang_stats.ban_period_seconds = DRM_I915_CTX_BAN_PERIOD; + ctx->jump_whitelist = NULL; + ctx->jump_whitelist_cmds = 0; + return ctx; err_out: diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c index 556849350f27..c373c45ae3d3 100644 --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c @@ -1154,7 +1154,8 @@ shadow_batch_pin(struct drm_i915_gem_object *obj, struct i915_address_space *vm) } static struct drm_i915_gem_object* -i915_gem_execbuffer_parse(struct intel_engine_cs *ring, +i915_gem_execbuffer_parse(struct intel_context *ctx, + struct intel_engine_cs *ring, struct drm_i915_gem_exec_object2 *shadow_exec_entry, struct eb_vmas *eb, struct i915_address_space *vm, @@ -1164,6 +1165,10 @@ i915_gem_execbuffer_parse(struct intel_engine_cs *ring, { struct drm_i915_gem_object *shadow_batch_obj; struct i915_vma *vma; + struct i915_vma *user_vma = list_entry(eb->vmas.prev, + typeof(*user_vma), exec_list); + u64 batch_start; + u64 shadow_batch_start; int ret; shadow_batch_obj = i915_gem_batch_pool_get(&ring->batch_pool, @@ -1171,20 +1176,30 @@ i915_gem_execbuffer_parse(struct intel_engine_cs *ring, if (IS_ERR(shadow_batch_obj)) return shadow_batch_obj; - ret = i915_parse_cmds(ring, - batch_obj, - shadow_batch_obj, - batch_start_offset, - batch_len); - if (ret) - goto err; - vma = shadow_batch_pin(shadow_batch_obj, vm); if (IS_ERR(vma)) { ret = PTR_ERR(vma); goto err; } + batch_start = user_vma->node.start + batch_start_offset; + + shadow_batch_start = vma->node.start; + + ret = i915_parse_cmds(ctx, + ring, + batch_obj, + batch_start, + batch_start_offset, + batch_len, + shadow_batch_obj, + shadow_batch_start); + if (ret) { + WARN_ON(vma->pin_count == 0); + vma->pin_count--; + goto err; + } + i915_gem_object_unpin_pages(shadow_batch_obj); memset(shadow_exec_entry, 0, sizeof(*shadow_exec_entry)); @@ -1545,7 +1560,7 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data, if (batch_len == 0) batch_len = batch_obj->base.size - batch_off; - parsed_batch_obj = i915_gem_execbuffer_parse(ring, + parsed_batch_obj = i915_gem_execbuffer_parse(ctx, ring, &shadow_exec_entry, eb, vm, batch_obj,