/**
* DOC: Shader validator for VC4.
*
- * The VC4 has no IOMMU between it and system memory. So, a user with access
- * to execute shaders could escalate privilege by overwriting system memory
- * (using the VPM write address register in the general-purpose DMA mode) or
- * reading system memory it shouldn't (reading it as a texture, or uniform
- * data, or vertex data).
+ * The VC4 has no IOMMU between it and system memory, so a user with
+ * access to execute shaders could escalate privilege by overwriting
+ * system memory (using the VPM write address register in the
+ * general-purpose DMA mode) or reading system memory it shouldn't
+ * (reading it as a texture, or uniform data, or vertex data).
*
- * This walks over a shader starting from some offset within a BO, ensuring
- * that its accesses are appropriately bounded, and recording how many texture
- * accesses are made and where so that we can do relocations for them in the
+ * This walks over a shader BO, ensuring that its accesses are
+ * appropriately bounded, and recording how many texture accesses are
+ * made and where so that we can do relocations for them in the
* uniform stream.
- *
- * The kernel API has shaders stored in user-mapped BOs. The BOs will be
- * forcibly unmapped from the process before validation, and any cache of
- * validated state will be flushed if the mapping is faulted back in.
- *
- * Storing the shaders in BOs means that the validation process will be slow
- * due to uncached reads, but since shaders are long-lived and shader BOs are
- * never actually modified, this shouldn't be a problem.
*/
#include "vc4_drv.h"
#include "vc4_qpu.h"
#include "vc4_qpu_defines.h"
+#define LIVE_REG_COUNT (32 + 32 + 4)
+
struct vc4_shader_validation_state {
+ /* Current IP being validated. */
+ uint32_t ip;
+
+ /* IP at the end of the BO, do not read shader[max_ip] */
+ uint32_t max_ip;
+
+ uint64_t *shader;
+
struct vc4_texture_sample_info tmu_setup[2];
int tmu_write_count[2];
+
+ /* For registers that were last written to by a MIN instruction with
+ * one argument being a uniform, the address of the uniform.
+ * Otherwise, ~0.
+ *
+ * This is used for the validation of direct address memory reads.
+ */
+ uint32_t live_min_clamp_offsets[LIVE_REG_COUNT];
+ bool live_max_clamp_regs[LIVE_REG_COUNT];
+ uint32_t live_immediates[LIVE_REG_COUNT];
+
+ /* Bitfield of which IPs are used as branch targets.
+ *
+ * Used for validation that the uniform stream is updated at the right
+ * points and clearing the texturing/clamping state.
+ */
+ unsigned long *branch_targets;
+
+ /* Set when entering a basic block, and cleared when the uniform
+ * address update is found. This is used to make sure that we don't
+ * read uniforms when the address is undefined.
+ */
+ bool needs_uniform_address_update;
+
+ /* Set when we find a backwards branch. If the branch is backwards,
+ * the taraget is probably doing an address reset to read uniforms,
+ * and so we need to be sure that a uniforms address is present in the
+ * stream, even if the shader didn't need to read uniforms in later
+ * basic blocks.
+ */
+ bool needs_uniform_address_for_loop;
};
+static uint32_t
+waddr_to_live_reg_index(uint32_t waddr, bool is_b)
+{
+ if (waddr < 32) {
+ if (is_b)
+ return 32 + waddr;
+ else
+ return waddr;
+ } else if (waddr <= QPU_W_ACC3) {
+ return 64 + waddr - QPU_W_ACC0;
+ } else {
+ return ~0;
+ }
+}
+
+static uint32_t
+raddr_add_a_to_live_reg_index(uint64_t inst)
+{
+ uint32_t sig = QPU_GET_FIELD(inst, QPU_SIG);
+ uint32_t add_a = QPU_GET_FIELD(inst, QPU_ADD_A);
+ uint32_t raddr_a = QPU_GET_FIELD(inst, QPU_RADDR_A);
+ uint32_t raddr_b = QPU_GET_FIELD(inst, QPU_RADDR_B);
+
+ if (add_a == QPU_MUX_A)
+ return raddr_a;
+ else if (add_a == QPU_MUX_B && sig != QPU_SIG_SMALL_IMM)
+ return 32 + raddr_b;
+ else if (add_a <= QPU_MUX_R3)
+ return 64 + add_a;
+ else
+ return ~0;
+}
+
+static bool
+is_tmu_submit(uint32_t waddr)
+{
+ return (waddr == QPU_W_TMU0_S ||
+ waddr == QPU_W_TMU1_S);
+}
+
static bool
is_tmu_write(uint32_t waddr)
{
}
static bool
-record_validated_texture_sample(struct vc4_validated_shader_info *validated_shader,
- struct vc4_shader_validation_state *validation_state,
- int tmu)
+record_texture_sample(struct vc4_validated_shader_info *validated_shader,
+ struct vc4_shader_validation_state *validation_state,
+ int tmu)
{
uint32_t s = validated_shader->num_texture_samples;
int i;
if (!temp_samples)
return false;
- memcpy(temp_samples[s].p_offset,
- validation_state->tmu_setup[tmu].p_offset,
- validation_state->tmu_write_count[tmu] * sizeof(uint32_t));
- for (i = validation_state->tmu_write_count[tmu]; i < 4; i++)
- temp_samples[s].p_offset[i] = ~0;
+ memcpy(&temp_samples[s],
+ &validation_state->tmu_setup[tmu],
+ sizeof(*temp_samples));
validated_shader->num_texture_samples = s + 1;
validated_shader->texture_samples = temp_samples;
+ for (i = 0; i < 4; i++)
+ validation_state->tmu_setup[tmu].p_offset[i] = ~0;
+
return true;
}
static bool
check_tmu_write(struct vc4_validated_shader_info *validated_shader,
struct vc4_shader_validation_state *validation_state,
- uint32_t waddr)
+ bool is_mul)
{
+ uint64_t inst = validation_state->shader[validation_state->ip];
+ uint32_t waddr = (is_mul ?
+ QPU_GET_FIELD(inst, QPU_WADDR_MUL) :
+ QPU_GET_FIELD(inst, QPU_WADDR_ADD));
+ uint32_t raddr_a = QPU_GET_FIELD(inst, QPU_RADDR_A);
+ uint32_t raddr_b = QPU_GET_FIELD(inst, QPU_RADDR_B);
int tmu = waddr > QPU_W_TMU0_B;
+ bool submit = is_tmu_submit(waddr);
+ bool is_direct = submit && validation_state->tmu_write_count[tmu] == 0;
+ uint32_t sig = QPU_GET_FIELD(inst, QPU_SIG);
+
+ if (is_direct) {
+ uint32_t add_b = QPU_GET_FIELD(inst, QPU_ADD_B);
+ uint32_t clamp_reg, clamp_offset;
+
+ if (sig == QPU_SIG_SMALL_IMM) {
+ DRM_ERROR("direct TMU read used small immediate\n");
+ return false;
+ }
+
+ /* Make sure that this texture load is an add of the base
+ * address of the UBO to a clamped offset within the UBO.
+ */
+ if (is_mul ||
+ QPU_GET_FIELD(inst, QPU_OP_ADD) != QPU_A_ADD) {
+ DRM_ERROR("direct TMU load wasn't an add\n");
+ return false;
+ }
+
+ /* We assert that the clamped address is the first
+ * argument, and the UBO base address is the second argument.
+ * This is arbitrary, but simpler than supporting flipping the
+ * two either way.
+ */
+ clamp_reg = raddr_add_a_to_live_reg_index(inst);
+ if (clamp_reg == ~0) {
+ DRM_ERROR("direct TMU load wasn't clamped\n");
+ return false;
+ }
+
+ clamp_offset = validation_state->live_min_clamp_offsets[clamp_reg];
+ if (clamp_offset == ~0) {
+ DRM_ERROR("direct TMU load wasn't clamped\n");
+ return false;
+ }
+
+ /* Store the clamp value's offset in p1 (see reloc_tex() in
+ * vc4_validate.c).
+ */
+ validation_state->tmu_setup[tmu].p_offset[1] =
+ clamp_offset;
+
+ if (!(add_b == QPU_MUX_A && raddr_a == QPU_R_UNIF) &&
+ !(add_b == QPU_MUX_B && raddr_b == QPU_R_UNIF)) {
+ DRM_ERROR("direct TMU load didn't add to a uniform\n");
+ return false;
+ }
+
+ validation_state->tmu_setup[tmu].is_direct = true;
+ } else {
+ if (raddr_a == QPU_R_UNIF || (sig != QPU_SIG_SMALL_IMM &&
+ raddr_b == QPU_R_UNIF)) {
+ DRM_ERROR("uniform read in the same instruction as "
+ "texture setup.\n");
+ return false;
+ }
+ }
if (validation_state->tmu_write_count[tmu] >= 4) {
DRM_ERROR("TMU%d got too many parameters before dispatch\n",
validation_state->tmu_setup[tmu].p_offset[validation_state->tmu_write_count[tmu]] =
validated_shader->uniforms_size;
validation_state->tmu_write_count[tmu]++;
- validated_shader->uniforms_size += 4;
+ /* Since direct uses a RADDR uniform reference, it will get counted in
+ * check_instruction_reads()
+ */
+ if (!is_direct) {
+ if (validation_state->needs_uniform_address_update) {
+ DRM_ERROR("Texturing with undefined uniform address\n");
+ return false;
+ }
+
+ validated_shader->uniforms_size += 4;
+ }
- if (waddr == QPU_W_TMU0_S || waddr == QPU_W_TMU1_S) {
- if (!record_validated_texture_sample(validated_shader,
- validation_state, tmu)) {
+ if (submit) {
+ if (!record_texture_sample(validated_shader,
+ validation_state, tmu)) {
return false;
}
return true;
}
+static bool require_uniform_address_uniform(struct vc4_validated_shader_info *validated_shader)
+{
+ uint32_t o = validated_shader->num_uniform_addr_offsets;
+ uint32_t num_uniforms = validated_shader->uniforms_size / 4;
+
+ validated_shader->uniform_addr_offsets =
+ krealloc(validated_shader->uniform_addr_offsets,
+ (o + 1) *
+ sizeof(*validated_shader->uniform_addr_offsets),
+ GFP_KERNEL);
+ if (!validated_shader->uniform_addr_offsets)
+ return false;
+
+ validated_shader->uniform_addr_offsets[o] = num_uniforms;
+ validated_shader->num_uniform_addr_offsets++;
+
+ return true;
+}
+
+static bool
+validate_uniform_address_write(struct vc4_validated_shader_info *validated_shader,
+ struct vc4_shader_validation_state *validation_state,
+ bool is_mul)
+{
+ uint64_t inst = validation_state->shader[validation_state->ip];
+ u32 add_b = QPU_GET_FIELD(inst, QPU_ADD_B);
+ u32 raddr_a = QPU_GET_FIELD(inst, QPU_RADDR_A);
+ u32 raddr_b = QPU_GET_FIELD(inst, QPU_RADDR_B);
+ u32 add_lri = raddr_add_a_to_live_reg_index(inst);
+ /* We want our reset to be pointing at whatever uniform follows the
+ * uniforms base address.
+ */
+ u32 expected_offset = validated_shader->uniforms_size + 4;
+
+ /* We only support absolute uniform address changes, and we
+ * require that they be in the current basic block before any
+ * of its uniform reads.
+ *
+ * One could potentially emit more efficient QPU code, by
+ * noticing that (say) an if statement does uniform control
+ * flow for all threads and that the if reads the same number
+ * of uniforms on each side. However, this scheme is easy to
+ * validate so it's all we allow for now.
+ */
+
+ if (QPU_GET_FIELD(inst, QPU_SIG) != QPU_SIG_NONE) {
+ DRM_ERROR("uniforms address change must be "
+ "normal math\n");
+ return false;
+ }
+
+ if (is_mul || QPU_GET_FIELD(inst, QPU_OP_ADD) != QPU_A_ADD) {
+ DRM_ERROR("Uniform address reset must be an ADD.\n");
+ return false;
+ }
+
+ if (QPU_GET_FIELD(inst, QPU_COND_ADD) != QPU_COND_ALWAYS) {
+ DRM_ERROR("Uniform address reset must be unconditional.\n");
+ return false;
+ }
+
+ if (QPU_GET_FIELD(inst, QPU_PACK) != QPU_PACK_A_NOP &&
+ !(inst & QPU_PM)) {
+ DRM_ERROR("No packing allowed on uniforms reset\n");
+ return false;
+ }
+
+ if (add_lri == -1) {
+ DRM_ERROR("First argument of uniform address write must be "
+ "an immediate value.\n");
+ return false;
+ }
+
+ if (validation_state->live_immediates[add_lri] != expected_offset) {
+ DRM_ERROR("Resetting uniforms with offset %db instead of %db\n",
+ validation_state->live_immediates[add_lri],
+ expected_offset);
+ return false;
+ }
+
+ if (!(add_b == QPU_MUX_A && raddr_a == QPU_R_UNIF) &&
+ !(add_b == QPU_MUX_B && raddr_b == QPU_R_UNIF)) {
+ DRM_ERROR("Second argument of uniform address write must be "
+ "a uniform.\n");
+ return false;
+ }
+
+ validation_state->needs_uniform_address_update = false;
+ validation_state->needs_uniform_address_for_loop = false;
+ return require_uniform_address_uniform(validated_shader);
+}
+
static bool
-check_register_write(struct vc4_validated_shader_info *validated_shader,
- struct vc4_shader_validation_state *validation_state,
- uint32_t waddr)
+check_reg_write(struct vc4_validated_shader_info *validated_shader,
+ struct vc4_shader_validation_state *validation_state,
+ bool is_mul)
{
+ uint64_t inst = validation_state->shader[validation_state->ip];
+ uint32_t waddr = (is_mul ?
+ QPU_GET_FIELD(inst, QPU_WADDR_MUL) :
+ QPU_GET_FIELD(inst, QPU_WADDR_ADD));
+ uint32_t sig = QPU_GET_FIELD(inst, QPU_SIG);
+ bool ws = inst & QPU_WS;
+ bool is_b = is_mul ^ ws;
+ u32 lri = waddr_to_live_reg_index(waddr, is_b);
+
+ if (lri != -1) {
+ uint32_t cond_add = QPU_GET_FIELD(inst, QPU_COND_ADD);
+ uint32_t cond_mul = QPU_GET_FIELD(inst, QPU_COND_MUL);
+
+ if (sig == QPU_SIG_LOAD_IMM &&
+ QPU_GET_FIELD(inst, QPU_PACK) == QPU_PACK_A_NOP &&
+ ((is_mul && cond_mul == QPU_COND_ALWAYS) ||
+ (!is_mul && cond_add == QPU_COND_ALWAYS))) {
+ validation_state->live_immediates[lri] =
+ QPU_GET_FIELD(inst, QPU_LOAD_IMM);
+ } else {
+ validation_state->live_immediates[lri] = ~0;
+ }
+ }
+
switch (waddr) {
case QPU_W_UNIFORMS_ADDRESS:
- /* XXX: We'll probably need to support this for reladdr, but
- * it's definitely a security-related one.
- */
- DRM_ERROR("uniforms address load unsupported\n");
- return false;
+ if (is_b) {
+ DRM_ERROR("relative uniforms address change "
+ "unsupported\n");
+ return false;
+ }
+
+ return validate_uniform_address_write(validated_shader,
+ validation_state,
+ is_mul);
case QPU_W_TLB_COLOR_MS:
case QPU_W_TLB_COLOR_ALL:
case QPU_W_TMU1_R:
case QPU_W_TMU1_B:
return check_tmu_write(validated_shader, validation_state,
- waddr);
+ is_mul);
case QPU_W_HOST_INT:
case QPU_W_TMU_NOSWAP:
return true;
case QPU_W_TLB_STENCIL_SETUP:
- return true;
+ return true;
}
return true;
}
+static void
+track_live_clamps(struct vc4_validated_shader_info *validated_shader,
+ struct vc4_shader_validation_state *validation_state)
+{
+ uint64_t inst = validation_state->shader[validation_state->ip];
+ uint32_t op_add = QPU_GET_FIELD(inst, QPU_OP_ADD);
+ uint32_t waddr_add = QPU_GET_FIELD(inst, QPU_WADDR_ADD);
+ uint32_t waddr_mul = QPU_GET_FIELD(inst, QPU_WADDR_MUL);
+ uint32_t cond_add = QPU_GET_FIELD(inst, QPU_COND_ADD);
+ uint32_t add_a = QPU_GET_FIELD(inst, QPU_ADD_A);
+ uint32_t add_b = QPU_GET_FIELD(inst, QPU_ADD_B);
+ uint32_t raddr_a = QPU_GET_FIELD(inst, QPU_RADDR_A);
+ uint32_t raddr_b = QPU_GET_FIELD(inst, QPU_RADDR_B);
+ uint32_t sig = QPU_GET_FIELD(inst, QPU_SIG);
+ bool ws = inst & QPU_WS;
+ uint32_t lri_add_a, lri_add, lri_mul;
+ bool add_a_is_min_0;
+
+ /* Check whether OP_ADD's A argumennt comes from a live MAX(x, 0),
+ * before we clear previous live state.
+ */
+ lri_add_a = raddr_add_a_to_live_reg_index(inst);
+ add_a_is_min_0 = (lri_add_a != ~0 &&
+ validation_state->live_max_clamp_regs[lri_add_a]);
+
+ /* Clear live state for registers written by our instruction. */
+ lri_add = waddr_to_live_reg_index(waddr_add, ws);
+ lri_mul = waddr_to_live_reg_index(waddr_mul, !ws);
+ if (lri_mul != ~0) {
+ validation_state->live_max_clamp_regs[lri_mul] = false;
+ validation_state->live_min_clamp_offsets[lri_mul] = ~0;
+ }
+ if (lri_add != ~0) {
+ validation_state->live_max_clamp_regs[lri_add] = false;
+ validation_state->live_min_clamp_offsets[lri_add] = ~0;
+ } else {
+ /* Nothing further to do for live tracking, since only ADDs
+ * generate new live clamp registers.
+ */
+ return;
+ }
+
+ /* Now, handle remaining live clamp tracking for the ADD operation. */
+
+ if (cond_add != QPU_COND_ALWAYS)
+ return;
+
+ if (op_add == QPU_A_MAX) {
+ /* Track live clamps of a value to a minimum of 0 (in either
+ * arg).
+ */
+ if (sig != QPU_SIG_SMALL_IMM || raddr_b != 0 ||
+ (add_a != QPU_MUX_B && add_b != QPU_MUX_B)) {
+ return;
+ }
+
+ validation_state->live_max_clamp_regs[lri_add] = true;
+ } else if (op_add == QPU_A_MIN) {
+ /* Track live clamps of a value clamped to a minimum of 0 and
+ * a maximum of some uniform's offset.
+ */
+ if (!add_a_is_min_0)
+ return;
+
+ if (!(add_b == QPU_MUX_A && raddr_a == QPU_R_UNIF) &&
+ !(add_b == QPU_MUX_B && raddr_b == QPU_R_UNIF &&
+ sig != QPU_SIG_SMALL_IMM)) {
+ return;
+ }
+
+ validation_state->live_min_clamp_offsets[lri_add] =
+ validated_shader->uniforms_size;
+ }
+}
+
static bool
-check_instruction_writes(uint64_t inst,
- struct vc4_validated_shader_info *validated_shader,
+check_instruction_writes(struct vc4_validated_shader_info *validated_shader,
struct vc4_shader_validation_state *validation_state)
{
+ uint64_t inst = validation_state->shader[validation_state->ip];
uint32_t waddr_add = QPU_GET_FIELD(inst, QPU_WADDR_ADD);
uint32_t waddr_mul = QPU_GET_FIELD(inst, QPU_WADDR_MUL);
+ bool ok;
if (is_tmu_write(waddr_add) && is_tmu_write(waddr_mul)) {
DRM_ERROR("ADD and MUL both set up textures\n");
return false;
}
- return (check_register_write(validated_shader, validation_state, waddr_add) &&
- check_register_write(validated_shader, validation_state, waddr_mul));
+ ok = (check_reg_write(validated_shader, validation_state, false) &&
+ check_reg_write(validated_shader, validation_state, true));
+
+ track_live_clamps(validated_shader, validation_state);
+
+ return ok;
}
static bool
-check_instruction_reads(uint64_t inst,
- struct vc4_validated_shader_info *validated_shader)
+check_branch(uint64_t inst,
+ struct vc4_validated_shader_info *validated_shader,
+ struct vc4_shader_validation_state *validation_state,
+ int ip)
{
+ int32_t branch_imm = QPU_GET_FIELD(inst, QPU_BRANCH_TARGET);
uint32_t waddr_add = QPU_GET_FIELD(inst, QPU_WADDR_ADD);
uint32_t waddr_mul = QPU_GET_FIELD(inst, QPU_WADDR_MUL);
+
+ if ((int)branch_imm < 0)
+ validation_state->needs_uniform_address_for_loop = true;
+
+ /* We don't want to have to worry about validation of this, and
+ * there's no need for it.
+ */
+ if (waddr_add != QPU_W_NOP || waddr_mul != QPU_W_NOP) {
+ DRM_ERROR("branch instruction at %d wrote a register.\n",
+ validation_state->ip);
+ return false;
+ }
+
+ return true;
+}
+
+static bool
+check_instruction_reads(struct vc4_validated_shader_info *validated_shader,
+ struct vc4_shader_validation_state *validation_state)
+{
+ uint64_t inst = validation_state->shader[validation_state->ip];
uint32_t raddr_a = QPU_GET_FIELD(inst, QPU_RADDR_A);
uint32_t raddr_b = QPU_GET_FIELD(inst, QPU_RADDR_B);
+ uint32_t sig = QPU_GET_FIELD(inst, QPU_SIG);
if (raddr_a == QPU_R_UNIF ||
- raddr_b == QPU_R_UNIF) {
- if (is_tmu_write(waddr_add) || is_tmu_write(waddr_mul)) {
- DRM_ERROR("uniform read in the same instruction as "
- "texture setup\n");
- return false;
- }
-
+ (raddr_b == QPU_R_UNIF && sig != QPU_SIG_SMALL_IMM)) {
/* This can't overflow the uint32_t, because we're reading 8
* bytes of instruction to increment by 4 here, so we'd
* already be OOM.
*/
validated_shader->uniforms_size += 4;
+
+ if (validation_state->needs_uniform_address_update) {
+ DRM_ERROR("Uniform read with undefined uniform "
+ "address\n");
+ return false;
+ }
}
return true;
}
+/* Make sure that all branches are absolute and point within the shader, and
+ * note their targets for later.
+ */
+static bool
+vc4_validate_branches(struct vc4_shader_validation_state *validation_state)
+{
+ uint32_t max_branch_target = 0;
+ bool found_shader_end = false;
+ int ip;
+ int shader_end_ip = 0;
+ int last_branch = -2;
+
+ for (ip = 0; ip < validation_state->max_ip; ip++) {
+ uint64_t inst = validation_state->shader[ip];
+ int32_t branch_imm = QPU_GET_FIELD(inst, QPU_BRANCH_TARGET);
+ uint32_t sig = QPU_GET_FIELD(inst, QPU_SIG);
+ uint32_t after_delay_ip = ip + 4;
+ uint32_t branch_target_ip;
+
+ if (sig == QPU_SIG_PROG_END) {
+ shader_end_ip = ip;
+ found_shader_end = true;
+ continue;
+ }
+
+ if (sig != QPU_SIG_BRANCH)
+ continue;
+
+ if (ip - last_branch < 4) {
+ DRM_ERROR("Branch at %d during delay slots\n", ip);
+ return false;
+ }
+ last_branch = ip;
+
+ if (inst & QPU_BRANCH_REG) {
+ DRM_ERROR("branching from register relative "
+ "not supported\n");
+ return false;
+ }
+
+ if (!(inst & QPU_BRANCH_REL)) {
+ DRM_ERROR("relative branching required\n");
+ return false;
+ }
+
+ /* The actual branch target is the instruction after the delay
+ * slots, plus whatever byte offset is in the low 32 bits of
+ * the instruction. Make sure we're not branching beyond the
+ * end of the shader object.
+ */
+ if (branch_imm % sizeof(inst) != 0) {
+ DRM_ERROR("branch target not aligned\n");
+ return false;
+ };
+
+ branch_target_ip = after_delay_ip + (branch_imm >> 3);
+ if (branch_target_ip >= validation_state->max_ip) {
+ DRM_ERROR("Branch at %d outside of shader (ip %d/%d)\n",
+ ip, branch_target_ip,
+ validation_state->max_ip);
+ return false;
+ }
+ set_bit(branch_target_ip, validation_state->branch_targets);
+
+ /* Make sure that the non-branching path is also not outside
+ * the shader.
+ */
+ if (after_delay_ip >= validation_state->max_ip) {
+ DRM_ERROR("Branch at %d continues past shader end "
+ "(%d/%d)\n",
+ ip, after_delay_ip, validation_state->max_ip);
+ return false;
+ }
+ set_bit(after_delay_ip, validation_state->branch_targets);
+ max_branch_target = max(max_branch_target, after_delay_ip);
+
+ /* There are two delay slots after program end is signaled
+ * that are still executed, then we're finished.
+ */
+ if (found_shader_end && ip == shader_end_ip + 2)
+ break;
+ }
+
+ if (max_branch_target > shader_end_ip) {
+ DRM_ERROR("Branch landed after QPU_SIG_PROG_END");
+ return false;
+ }
+
+ return true;
+}
+
+/* Resets any known state for the shader, used when we may be branched to from
+ * multiple locations in the program (or at shader start).
+ */
+static void
+reset_validation_state(struct vc4_shader_validation_state *validation_state)
+{
+ int i;
+
+ for (i = 0; i < 8; i++)
+ validation_state->tmu_setup[i / 4].p_offset[i % 4] = ~0;
+
+ for (i = 0; i < LIVE_REG_COUNT; i++) {
+ validation_state->live_min_clamp_offsets[i] = ~0;
+ validation_state->live_max_clamp_regs[i] = false;
+ validation_state->live_immediates[i] = ~0;
+ }
+}
+
+static bool
+texturing_in_progress(struct vc4_shader_validation_state *validation_state)
+{
+ return (validation_state->tmu_write_count[0] != 0 ||
+ validation_state->tmu_write_count[1] != 0);
+}
+
+static bool
+vc4_handle_branch_target(struct vc4_shader_validation_state *validation_state)
+{
+ uint32_t ip = validation_state->ip;
+
+ if (!test_bit(ip, validation_state->branch_targets))
+ return true;
+
+ if (texturing_in_progress(validation_state)) {
+ DRM_ERROR("Branch target landed during TMU setup\n");
+ return false;
+ }
+
+ /* Reset our live values tracking, since this instruction may have
+ * multiple predecessors.
+ *
+ * One could potentially do analysis to determine that, for
+ * example, all predecessors have a live max clamp in the same
+ * register, but we don't bother with that.
+ */
+ reset_validation_state(validation_state);
+
+ /* Since we've entered a basic block from potentially multiple
+ * predecessors, we need the uniforms address to be updated before any
+ * unforms are read. We require that after any branch point, the next
+ * uniform to be loaded is a uniform address offset. That uniform's
+ * offset will be marked by the uniform address register write
+ * validation, or a one-off the end-of-program check.
+ */
+ validation_state->needs_uniform_address_update = true;
+
+ return true;
+}
+
struct vc4_validated_shader_info *
-vc4_validate_shader(struct drm_gem_cma_object *shader_obj,
- uint32_t start_offset)
+vc4_validate_shader(struct drm_gem_cma_object *shader_obj)
{
bool found_shader_end = false;
int shader_end_ip = 0;
- uint32_t ip, max_ip;
- uint64_t *shader;
- struct vc4_validated_shader_info *validated_shader;
+ uint32_t ip;
+ struct vc4_validated_shader_info *validated_shader = NULL;
struct vc4_shader_validation_state validation_state;
memset(&validation_state, 0, sizeof(validation_state));
+ validation_state.shader = shader_obj->vaddr;
+ validation_state.max_ip = shader_obj->base.size / sizeof(uint64_t);
- if (start_offset + sizeof(uint64_t) > shader_obj->base.size) {
- DRM_ERROR("shader starting at %d outside of BO sized %d\n",
- start_offset,
- shader_obj->base.size);
- return NULL;
- }
- shader = shader_obj->vaddr + start_offset;
- max_ip = (shader_obj->base.size - start_offset) / sizeof(uint64_t);
+ reset_validation_state(&validation_state);
- validated_shader = kcalloc(sizeof(*validated_shader), 1, GFP_KERNEL);
+ validation_state.branch_targets =
+ kcalloc(BITS_TO_LONGS(validation_state.max_ip),
+ sizeof(unsigned long), GFP_KERNEL);
+ if (!validation_state.branch_targets)
+ goto fail;
+
+ validated_shader = kcalloc(1, sizeof(*validated_shader), GFP_KERNEL);
if (!validated_shader)
- return NULL;
+ goto fail;
- for (ip = 0; ip < max_ip; ip++) {
- uint64_t inst = shader[ip];
+ if (!vc4_validate_branches(&validation_state))
+ goto fail;
+
+ for (ip = 0; ip < validation_state.max_ip; ip++) {
+ uint64_t inst = validation_state.shader[ip];
uint32_t sig = QPU_GET_FIELD(inst, QPU_SIG);
+ validation_state.ip = ip;
+
+ if (!vc4_handle_branch_target(&validation_state))
+ goto fail;
+
switch (sig) {
case QPU_SIG_NONE:
case QPU_SIG_WAIT_FOR_SCOREBOARD:
case QPU_SIG_LOAD_TMU0:
case QPU_SIG_LOAD_TMU1:
case QPU_SIG_PROG_END:
- if (!check_instruction_writes(inst, validated_shader,
+ case QPU_SIG_SMALL_IMM:
+ if (!check_instruction_writes(validated_shader,
&validation_state)) {
DRM_ERROR("Bad write at ip %d\n", ip);
goto fail;
}
- if (!check_instruction_reads(inst, validated_shader))
+ if (!check_instruction_reads(validated_shader,
+ &validation_state))
goto fail;
if (sig == QPU_SIG_PROG_END) {
break;
case QPU_SIG_LOAD_IMM:
- if (!check_instruction_writes(inst, validated_shader,
+ if (!check_instruction_writes(validated_shader,
&validation_state)) {
DRM_ERROR("Bad LOAD_IMM write at ip %d\n", ip);
goto fail;
}
break;
+ case QPU_SIG_BRANCH:
+ if (!check_branch(inst, validated_shader,
+ &validation_state, ip))
+ goto fail;
+ break;
default:
DRM_ERROR("Unsupported QPU signal %d at "
"instruction %d\n", sig, ip);
break;
}
- if (ip == max_ip) {
- DRM_ERROR("shader starting at %d failed to terminate before "
- "shader BO end at %d\n",
- start_offset,
+ if (ip == validation_state.max_ip) {
+ DRM_ERROR("shader failed to terminate before "
+ "shader BO end at %zd\n",
shader_obj->base.size);
goto fail;
}
+ /* If we did a backwards branch and we haven't emitted a uniforms
+ * reset since then, we still need the uniforms stream to have the
+ * uniforms address available so that the backwards branch can do its
+ * uniforms reset.
+ *
+ * We could potentially prove that the backwards branch doesn't
+ * contain any uses of uniforms until program exit, but that doesn't
+ * seem to be worth the trouble.
+ */
+ if (validation_state.needs_uniform_address_for_loop) {
+ if (!require_uniform_address_uniform(validated_shader))
+ goto fail;
+ validated_shader->uniforms_size += 4;
+ }
+
/* Again, no chance of integer overflow here because the worst case
* scenario is 8 bytes of uniforms plus handles per 8-byte
* instruction.
(validated_shader->uniforms_size +
4 * validated_shader->num_texture_samples);
+ kfree(validation_state.branch_targets);
+
return validated_shader;
fail:
- kfree(validated_shader);
+ kfree(validation_state.branch_targets);
+ if (validated_shader) {
+ kfree(validated_shader->texture_samples);
+ kfree(validated_shader);
+ }
return NULL;
}
projects / mesa.git / blobdiff