diff options
| -rw-r--r-- | target/arm/internals.h | 48 | ||||
| -rw-r--r-- | target/arm/mte_helper.c | 132 |
2 files changed, 179 insertions, 1 deletions
diff --git a/target/arm/internals.h b/target/arm/internals.h index fb92ef6b84..807830cc40 100644 --- a/target/arm/internals.h +++ b/target/arm/internals.h @@ -1318,6 +1318,10 @@ FIELD(MTEDESC, WRITE, 8, 1) FIELD(MTEDESC, ESIZE, 9, 5) FIELD(MTEDESC, TSIZE, 14, 10) /* mte_checkN only */ +bool mte_probe1(CPUARMState *env, uint32_t desc, uint64_t ptr); +uint64_t mte_check1(CPUARMState *env, uint32_t desc, + uint64_t ptr, uintptr_t ra); + static inline int allocation_tag_from_addr(uint64_t ptr) { return extract64(ptr, 56, 4); @@ -1328,4 +1332,48 @@ static inline uint64_t address_with_allocation_tag(uint64_t ptr, int rtag) return deposit64(ptr, 56, 4, rtag); } +/* Return true if tbi bits mean that the access is checked. */ +static inline bool tbi_check(uint32_t desc, int bit55) +{ + return (desc >> (R_MTEDESC_TBI_SHIFT + bit55)) & 1; +} + +/* Return true if tcma bits mean that the access is unchecked. */ +static inline bool tcma_check(uint32_t desc, int bit55, int ptr_tag) +{ + /* + * We had extracted bit55 and ptr_tag for other reasons, so fold + * (ptr<59:55> == 00000 || ptr<59:55> == 11111) into a single test. + */ + bool match = ((ptr_tag + bit55) & 0xf) == 0; + bool tcma = (desc >> (R_MTEDESC_TCMA_SHIFT + bit55)) & 1; + return tcma && match; +} + +/* + * For TBI, ideally, we would do nothing. Proper behaviour on fault is + * for the tag to be present in the FAR_ELx register. But for user-only + * mode, we do not have a TLB with which to implement this, so we must + * remove the top byte. + */ +static inline uint64_t useronly_clean_ptr(uint64_t ptr) +{ + /* TBI is known to be enabled. */ +#ifdef CONFIG_USER_ONLY + ptr = sextract64(ptr, 0, 56); +#endif + return ptr; +} + +static inline uint64_t useronly_maybe_clean_ptr(uint32_t desc, uint64_t ptr) +{ +#ifdef CONFIG_USER_ONLY + int64_t clean_ptr = sextract64(ptr, 0, 56); + if (tbi_check(desc, clean_ptr < 0)) { + ptr = clean_ptr; + } +#endif + return ptr; +} + #endif diff --git a/target/arm/mte_helper.c b/target/arm/mte_helper.c index 907a12b366..c8a5e7c0ed 100644 --- a/target/arm/mte_helper.c +++ b/target/arm/mte_helper.c @@ -359,12 +359,142 @@ void HELPER(stzgm_tags)(CPUARMState *env, uint64_t ptr, uint64_t val) } } +/* Record a tag check failure. */ +static void mte_check_fail(CPUARMState *env, int mmu_idx, + uint64_t dirty_ptr, uintptr_t ra) +{ + ARMMMUIdx arm_mmu_idx = core_to_aa64_mmu_idx(mmu_idx); + int el, reg_el, tcf, select; + uint64_t sctlr; + + reg_el = regime_el(env, arm_mmu_idx); + sctlr = env->cp15.sctlr_el[reg_el]; + + switch (arm_mmu_idx) { + case ARMMMUIdx_E10_0: + case ARMMMUIdx_E20_0: + el = 0; + tcf = extract64(sctlr, 38, 2); + break; + default: + el = reg_el; + tcf = extract64(sctlr, 40, 2); + } + + switch (tcf) { + case 1: + /* + * Tag check fail causes a synchronous exception. + * + * In restore_state_to_opc, we set the exception syndrome + * for the load or store operation. Unwind first so we + * may overwrite that with the syndrome for the tag check. + */ + cpu_restore_state(env_cpu(env), ra, true); + env->exception.vaddress = dirty_ptr; + raise_exception(env, EXCP_DATA_ABORT, + syn_data_abort_no_iss(el != 0, 0, 0, 0, 0, 0, 0x11), + exception_target_el(env)); + /* noreturn, but fall through to the assert anyway */ + + case 0: + /* + * Tag check fail does not affect the PE. + * We eliminate this case by not setting MTE_ACTIVE + * in tb_flags, so that we never make this runtime call. + */ + g_assert_not_reached(); + + case 2: + /* Tag check fail causes asynchronous flag set. */ + mmu_idx = arm_mmu_idx_el(env, el); + if (regime_has_2_ranges(mmu_idx)) { + select = extract64(dirty_ptr, 55, 1); + } else { + select = 0; + } + env->cp15.tfsr_el[el] |= 1 << select; + break; + + default: + /* Case 3: Reserved. */ + qemu_log_mask(LOG_GUEST_ERROR, + "Tag check failure with SCTLR_EL%d.TCF%s " + "set to reserved value %d\n", + reg_el, el ? "" : "0", tcf); + break; + } +} + /* * Perform an MTE checked access for a single logical or atomic access. */ +static bool mte_probe1_int(CPUARMState *env, uint32_t desc, uint64_t ptr, + uintptr_t ra, int bit55) +{ + int mem_tag, mmu_idx, ptr_tag, size; + MMUAccessType type; + uint8_t *mem; + + ptr_tag = allocation_tag_from_addr(ptr); + + if (tcma_check(desc, bit55, ptr_tag)) { + return true; + } + + mmu_idx = FIELD_EX32(desc, MTEDESC, MIDX); + type = FIELD_EX32(desc, MTEDESC, WRITE) ? MMU_DATA_STORE : MMU_DATA_LOAD; + size = FIELD_EX32(desc, MTEDESC, ESIZE); + + mem = allocation_tag_mem(env, mmu_idx, ptr, type, size, + MMU_DATA_LOAD, 1, ra); + if (!mem) { + return true; + } + + mem_tag = load_tag1(ptr, mem); + return ptr_tag == mem_tag; +} + +/* + * No-fault version of mte_check1, to be used by SVE for MemSingleNF. + * Returns false if the access is Checked and the check failed. This + * is only intended to probe the tag -- the validity of the page must + * be checked beforehand. + */ +bool mte_probe1(CPUARMState *env, uint32_t desc, uint64_t ptr) +{ + int bit55 = extract64(ptr, 55, 1); + + /* If TBI is disabled, the access is unchecked. */ + if (unlikely(!tbi_check(desc, bit55))) { + return true; + } + + return mte_probe1_int(env, desc, ptr, 0, bit55); +} + +uint64_t mte_check1(CPUARMState *env, uint32_t desc, + uint64_t ptr, uintptr_t ra) +{ + int bit55 = extract64(ptr, 55, 1); + + /* If TBI is disabled, the access is unchecked, and ptr is not dirty. */ + if (unlikely(!tbi_check(desc, bit55))) { + return ptr; + } + + if (unlikely(!mte_probe1_int(env, desc, ptr, ra, bit55))) { + int mmu_idx = FIELD_EX32(desc, MTEDESC, MIDX); + mte_check_fail(env, mmu_idx, ptr, ra); + } + + return useronly_clean_ptr(ptr); +} + uint64_t HELPER(mte_check1)(CPUARMState *env, uint32_t desc, uint64_t ptr) { - return ptr; + return mte_check1(env, desc, ptr, GETPC()); } /* |