Add Arm64 TSAN support and fix JIT cache coherency

This commit adds ThreadSanitizer (TSAN) support for ARM64/Apple Silicon
and fixes critical JIT instruction cache coherency issues.

ARM64 TSAN Support:
- Extended TSAN-compatible memory allocation to ARM64 architecture
- Main memory allocated at fixed address 0x150000000000 (21TB)
- JIT buffer allocated at 0x151000000000 with MAP_JIT for Apple Silicon
- Both allocations avoid TSAN shadow memory and enable race detection
- Note: Requires ASLR disabled on macOS (SIP restrictions may apply)

JIT Cache Coherency Fixes:
1. Fixed pthread_jit_write_protect_np() ordering in update_branch_imm
2. Added sys_icache_invalidate() in update_branch_imm
3. Added cache invalidation in resolve_jumps() for x86_64

Author: jserv

src/io.c

@@ -27,18 +27,32 @@ memory_t *memory_new(uint32_t size)
         return NULL;
     assert(mem);
 #if HAVE_MMAP
-#if defined(TSAN_ENABLED) && defined(__x86_64__)
+#if defined(TSAN_ENABLED)
     /* ThreadSanitizer compatibility: Use MAP_FIXED to allocate at a specific
-     * address within TSAN's app range (0x7cf000000000 - 0x7ffffffff000).
+     * address to avoid conflicts with TSAN's shadow memory.
+     */
+#if defined(__x86_64__)
+    /* x86_64: Allocate within TSAN's range (0x7cf000000000 - 0x7ffffffff000).
      *
      * Fixed address: 0x7d0000000000
      * Size: up to 4GB (0x100000000)
      * End: 0x7d0100000000 (well within app range)
-     *
-     * This guarantees the allocation won't land in TSAN's shadow memory,
-     * preventing "unexpected memory mapping" errors.
      */
     void *fixed_addr = (void *) 0x7d0000000000UL;
+#elif defined(__aarch64__)
+    /* ARM64 (macOS/Apple Silicon): Use higher address range.
+     *
+     * Fixed address: 0x150000000000 (21TB)
+     * Size: up to 4GB (0x100000000)
+     * End: 0x150100000000
+     *
+     * This avoids TSAN's shadow memory and typical process allocations.
+     * Requires ASLR disabled via: setarch $(uname -m) -R
+     */
+    void *fixed_addr = (void *) 0x150000000000UL;
+#else
+#error "TSAN is only supported on x86_64 and aarch64"
+#endif
     data_memory_base = mmap(fixed_addr, size, PROT_READ | PROT_WRITE,
                             MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0);
     if (data_memory_base == MAP_FAILED) {

src/jit.c

@@ -2336,10 +2336,12 @@ struct jit_state *jit_state_init(size_t size)
 
     state->offset = 0;
     state->size = size;
-#if defined(TSAN_ENABLED) && defined(__x86_64__)
+#if defined(TSAN_ENABLED)
     /* ThreadSanitizer compatibility: Allocate JIT code buffer at a fixed
      * address above the main memory region to avoid conflicts.
-     *
+     */
+#if defined(__x86_64__)
+    /* x86_64 memory layout:
      * Main memory: 0x7d0000000000 - 0x7d0100000000 (4GB for FULL4G)
      * JIT buffer:  0x7d1000000000 + size
      *
@@ -2349,6 +2351,26 @@ struct jit_state *jit_state_init(size_t size)
     void *jit_addr = (void *) 0x7d1000000000UL;
     state->buf = mmap(jit_addr, size, PROT_READ | PROT_WRITE | PROT_EXEC,
                       MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0);
+#elif defined(__aarch64__)
+    /* ARM64 memory layout (macOS/Apple Silicon):
+     * Main memory: 0x150000000000 - 0x150100000000 (4GB for FULL4G)
+     * JIT buffer:  0x151000000000 + size
+     *
+     * Apple Silicon requires MAP_JIT for executable memory. The fixed
+     * address is chosen to avoid TSAN's shadow memory and typical process
+     * allocations. Requires ASLR disabled via: setarch $(uname -m) -R
+     */
+    void *jit_addr = (void *) 0x151000000000UL;
+    state->buf = mmap(jit_addr, size, PROT_READ | PROT_WRITE | PROT_EXEC,
+                      MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED
+#if defined(__APPLE__)
+                          | MAP_JIT
+#endif
+                      ,
+                      -1, 0);
+#else
+#error "TSAN is only supported on x86_64 and aarch64"
+#endif
     if (state->buf == MAP_FAILED) {
         free(state);
         return NULL;