Re: [PATCH v3] tcg: Fix execution on Apple Silicon

[Richard Henderson]

On 1/21/21 8:34 AM, Richard Henderson wrote:
> On 1/12/21 5:28 PM, Roman Bolshakov wrote:
>> @@ -1083,6 +1083,12 @@ static bool alloc_code_gen_buffer_anon(size_t size, 
>> int prot,
>>  {
>>      void *buf;
>>  
>> +#if defined(MAC_OS_VERSION_11_0) && \
>> +    MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_VERSION_11_0
>> +    if (__builtin_available(macOS 11.0, *)) {
>> +        flags |= MAP_JIT;
>> +    }
>> +#endif
> 
> This hunk should be in alloc_code_gen_buffer, where we do the other flags
> manipulation.
> 
> I'll drop this hunk and apply the rest, which is exclusively related to
> toggling the jit bit.

Ping on this?

I would imagine that the patch would look something like

--- a/accel/tcg/translate-all.c
+++ b/accel/tcg/translate-all.c
@@ -1296,6 +1296,11 @@ static bool alloc_code_gen_buffer
 #ifdef CONFIG_TCG_INTERPRETER
     /* The tcg interpreter does not need execute permission. */
     prot = PROT_READ | PROT_WRITE;
+#elif defined(MAC_OS_VERSION_11_0) && \
+    MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_VERSION_11_0
+    if (__builtin_available(macOS 11.0, *)) {
+        flags |= MAP_JIT;
+    }
 #elif defined(CONFIG_DARWIN)
     /* Applicable to both iOS and macOS (Apple Silicon). */
     if (!splitwx) {

But I don't know how CONFIG_DARWIN, iOS, and MAC_OS_VERSION interact, and I'm
not able to even compile-test the patch.
Certainly the final comment there looks suspicious, given the preceding MAC_OS
stanza...


r~