target/arm: Fix unaligned checks for mte_check1, mte_probe1
We were incorrectly assuming that only the first byte of an MTE access
is checked against the tags. But per the ARM, unaligned accesses are
pre-decomposed into single-byte accesses. So by the time we reach the
actual MTE check in the ARM pseudocode, all accesses are aligned.
We cannot tell a priori whether or not a given scalar access is aligned,
therefore we must at least check. Use mte_probe_int, which is already
set up for checking multiple granules.
Buglink: https://bugs.launchpad.net/bugs/1921948
Tested-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210416183106.1516563-4-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
diff --git a/target/arm/mte_helper.c b/target/arm/mte_helper.c
index 2b5331f..0ee0397 100644
--- a/target/arm/mte_helper.c
+++ b/target/arm/mte_helper.c
@@ -617,80 +617,6 @@
}
}
-/*
- * 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))) {
- mte_check_fail(env, desc, ptr, ra);
- }
-
- return useronly_clean_ptr(ptr);
-}
-
-uint64_t HELPER(mte_check1)(CPUARMState *env, uint32_t desc, uint64_t ptr)
-{
- return mte_check1(env, desc, ptr, GETPC());
-}
-
-/*
- * Perform an MTE checked access for multiple logical accesses.
- */
-
/**
* checkN:
* @tag: tag memory to test
@@ -882,6 +808,41 @@
return mte_checkN(env, desc, ptr, GETPC());
}
+uint64_t mte_check1(CPUARMState *env, uint32_t desc,
+ uint64_t ptr, uintptr_t ra)
+{
+ uint64_t fault;
+ uint32_t total = FIELD_EX32(desc, MTEDESC, ESIZE);
+ int ret = mte_probe_int(env, desc, ptr, ra, total, &fault);
+
+ if (unlikely(ret == 0)) {
+ mte_check_fail(env, desc, fault, ra);
+ } else if (ret < 0) {
+ return ptr;
+ }
+ return useronly_clean_ptr(ptr);
+}
+
+uint64_t HELPER(mte_check1)(CPUARMState *env, uint32_t desc, uint64_t ptr)
+{
+ return mte_check1(env, desc, ptr, GETPC());
+}
+
+/*
+ * 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)
+{
+ uint64_t fault;
+ uint32_t total = FIELD_EX32(desc, MTEDESC, ESIZE);
+ int ret = mte_probe_int(env, desc, ptr, 0, total, &fault);
+
+ return ret != 0;
+}
+
/*
* Perform an MTE checked access for DC_ZVA.
*/
