AArch64: Small fixes inspired by LLM Review

Signed-off-by: Paul Guyot <[email protected]>

Author: pguyot

libs/jit/src/jit_aarch64_asm.erl

@@ -124,7 +124,7 @@ add(Rd, Rn, Rm, {lsl, Amount}) when
     RdNum = reg_to_num(Rd),
     RnNum = reg_to_num(Rn),
     RmNum = reg_to_num(Rm),
-    %% AArch64 ADD (immediate) encoding: 1001000100iiiiiiiiiiiinnnnndddddd
+    %% AArch64 ADD (shifted register) encoding: 10001011000mmmmmiiiiiinnnnndddddd
     %% 0x8B000000 | Rm << 16 | Amount << 10 | Rn << 5 | Rd
     <<
         (16#8B000000 bor (RmNum bsl 16) bor ((Amount band 16#3F) bsl 10) bor (RnNum bsl 5) bor

libs/jit/src/jit_precompile.erl

@@ -69,7 +69,8 @@ compile(Target, Dir, Path) ->
         Arch =
             case Target of
                 "x86_64" -> ?JIT_ARCH_X86_64;
-                "aarch64" -> ?JIT_ARCH_AARCH64
+                "aarch64" -> ?JIT_ARCH_AARCH64;
+                _ -> error({unsupported_target, Target})
             end,
 
         Stream1 = jit_stream_binary:append(

src/platforms/generic_unix/lib/jit_stream_mmap.c

@@ -29,6 +29,7 @@
 #include "platform_defaultatoms.h"
 #include "term.h"
 
+#include <errno.h>
 #include <pthread.h>
 #include <stdint.h>
 #include <stdio.h>
@@ -74,7 +75,7 @@ static term nif_jit_stream_mmap_new(Context *ctx, int argc, term argv[])
 
     uint8_t *addr = (uint8_t *) mmap(0, size, prot, flags, fd, offset);
     if (addr == MAP_FAILED) {
-        fprintf(stderr, "Could not allocate mmap for JIT");
+        fprintf(stderr, "Could not allocate mmap for JIT: size=%zu, errno=%d\n", size, errno);
         RAISE_ERROR(BADARG_ATOM);
     }
 
@@ -119,7 +120,9 @@ static term nif_jit_stream_mmap_append(Context *ctx, int argc, term argv[])
 
     size_t binary_size = term_binary_size(argv[1]);
     const uint8_t *binary_data = (const uint8_t *) term_binary_data(argv[1]);
-    assert(js_obj->stream_offset + binary_size < js_obj->stream_size);
+    if (UNLIKELY(js_obj->stream_offset + binary_size > js_obj->stream_size)) {
+        RAISE_ERROR(BADARG_ATOM);
+    }
 
 #if HAVE_PTHREAD_JIT_WRITE_PROTECT_NP
     pthread_jit_write_protect_np(0);

src/platforms/generic_unix/lib/sys.c

@@ -47,6 +47,8 @@
 
 #ifndef AVM_NO_JIT
 #include "jit_stream_mmap.h"
+
+#include <errno.h>
 #include <pthread.h>
 #include <sys/mman.h>
 
@@ -818,7 +820,7 @@ ModuleNativeEntryPoint sys_map_native_code(const uint8_t *native_code, size_t si
 #if defined(__APPLE__) && defined(__arm64__)
     uint8_t *native_code_mmap = (uint8_t *) mmap(0, size, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE | MAP_ANONYMOUS | MAP_JIT, -1, 0);
     if (native_code_mmap == MAP_FAILED) {
-        fprintf(stderr, "Could not allocate mmap for native code");
+        fprintf(stderr, "Could not allocate mmap for native code: size=%zu, errno=%d\n", size, errno);
         return NULL;
     }
     pthread_jit_write_protect_np(0);