[PATCH v1 14/19] target/arm: Check alignment in helper_mte_check

[Richard Henderson]

Fixes a bug in that with SCTLR.A set, we should raise any
alignment fault before raising any MTE check fault.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/internals.h     |  3 ++-
 target/arm/mte_helper.c    | 18 ++++++++++++++++++
 target/arm/translate-a64.c |  2 ++
 3 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/target/arm/internals.h b/target/arm/internals.h
index e1e018da46..fa264e368c 100644
--- a/target/arm/internals.h
+++ b/target/arm/internals.h
@@ -1222,7 +1222,8 @@ FIELD(MTEDESC, MIDX,  0, 4)
 FIELD(MTEDESC, TBI,   4, 2)
 FIELD(MTEDESC, TCMA,  6, 2)
 FIELD(MTEDESC, WRITE, 8, 1)
-FIELD(MTEDESC, SIZEM1, 9, SIMD_DATA_BITS - 9)  /* size - 1 */
+FIELD(MTEDESC, ALIGN, 9, 3)
+FIELD(MTEDESC, SIZEM1, 12, SIMD_DATA_BITS - 12)  /* size - 1 */
 
 bool mte_probe(CPUARMState *env, uint32_t desc, uint64_t ptr);
 uint64_t mte_check(CPUARMState *env, uint32_t desc, uint64_t ptr, uintptr_t 
ra);
diff --git a/target/arm/mte_helper.c b/target/arm/mte_helper.c
index 98bcf59c22..e50bb4ea13 100644
--- a/target/arm/mte_helper.c
+++ b/target/arm/mte_helper.c
@@ -784,6 +784,24 @@ uint64_t mte_check(CPUARMState *env, uint32_t desc, 
uint64_t ptr, uintptr_t ra)
 
 uint64_t HELPER(mte_check)(CPUARMState *env, uint32_t desc, uint64_t ptr)
 {
+    /*
+     * In the Arm ARM pseudocode, the alignment check happens at the top
+     * of Mem[], while the MTE check happens later in AArch64.MemSingle[].
+     * Thus the alignment check has priority.
+     * When the mte check is disabled, tcg performs the alignment check
+     * during the code generated for the memory access.
+     */
+    unsigned align = FIELD_EX32(desc, MTEDESC, ALIGN);
+    if (unlikely(align)) {
+        align = (1u << align) - 1;
+        if (unlikely(ptr & align)) {
+            int idx = FIELD_EX32(desc, MTEDESC, MIDX);
+            bool w = FIELD_EX32(desc, MTEDESC, WRITE);
+            MMUAccessType type = w ? MMU_DATA_STORE : MMU_DATA_LOAD;
+            arm_cpu_do_unaligned_access(env_cpu(env), ptr, type, idx, GETPC());
+        }
+    }
+
     return mte_check(env, desc, ptr, GETPC());
 }
 
diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index 1117a1cc41..caeb91efa5 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -267,6 +267,7 @@ static TCGv_i64 gen_mte_check1_mmuidx(DisasContext *s, 
TCGv_i64 addr,
         desc = FIELD_DP32(desc, MTEDESC, TBI, s->tbid);
         desc = FIELD_DP32(desc, MTEDESC, TCMA, s->tcma);
         desc = FIELD_DP32(desc, MTEDESC, WRITE, is_write);
+        desc = FIELD_DP32(desc, MTEDESC, ALIGN, get_alignment_bits(memop));
         desc = FIELD_DP32(desc, MTEDESC, SIZEM1, memop_size(memop) - 1);
 
         ret = new_tmp_a64(s);
@@ -298,6 +299,7 @@ TCGv_i64 gen_mte_checkN(DisasContext *s, TCGv_i64 addr, 
bool is_write,
         desc = FIELD_DP32(desc, MTEDESC, TBI, s->tbid);
         desc = FIELD_DP32(desc, MTEDESC, TCMA, s->tcma);
         desc = FIELD_DP32(desc, MTEDESC, WRITE, is_write);
+        desc = FIELD_DP32(desc, MTEDESC, ALIGN, 
get_alignment_bits(single_mop));
         desc = FIELD_DP32(desc, MTEDESC, SIZEM1, total_size - 1);
 
         ret = new_tmp_a64(s);
-- 
2.34.1