Merge pull request #896 from echampet/webresource

[mono.git] / mono / utils / mach-support-x86.c

diff --git a/mono/utils/mach-support-x86.c b/mono/utils/mach-support-x86.c
index d3c967d2ed8019a957721ecf2b2595eaea00ee05..3e8b166eaf2b51a7dc69f49d889c896762d75732 100644 (file)
--- a/mono/utils/mach-support-x86.c
+++ b/mono/utils/mach-support-x86.c
@@ -16,6 +16,22 @@
 #include "utils/mono-sigcontext.h"
 #include "mach-support.h"
 
+/* Known offsets used for TLS storage*/
+
+/* All OSX versions up to 10.8 */
+#define TLS_VECTOR_OFFSET_CATS 0x48
+#define TLS_VECTOR_OFFSET_10_9 0xb0
+#define TLS_VECTOR_OFFSET_10_11 0x100
+
+
+/* This is 2 slots less than the known low */
+#define TLS_PROBE_LOW_WATERMARK 0x40
+/* This is 28 slots above the know high, which is more than the known high-low*/
+#define TLS_PROBE_HIGH_WATERMARK 0x120
+
+
+static int tls_vector_offset;
+
 void *
 mono_mach_arch_get_ip (thread_state_t state)
 {
@@ -39,7 +55,7 @@ mono_mach_arch_get_mcontext_size ()
 }
 
 void
-mono_mach_arch_thread_state_to_mcontext (thread_state_t state, mcontext_t context)
+mono_mach_arch_thread_state_to_mcontext (thread_state_t state, void *context)
 {
        x86_thread_state32_t *arch_state = (x86_thread_state32_t *) state;
        struct __darwin_mcontext32 *ctx = (struct __darwin_mcontext32 *) context;
@@ -48,7 +64,7 @@ mono_mach_arch_thread_state_to_mcontext (thread_state_t state, mcontext_t contex
 }
 
 void
-mono_mach_arch_mcontext_to_thread_state (mcontext_t context, thread_state_t state)
+mono_mach_arch_mcontext_to_thread_state (void *context, thread_state_t state)
 {
        x86_thread_state32_t *arch_state = (x86_thread_state32_t *) state;
        struct __darwin_mcontext32 *ctx = (struct __darwin_mcontext32 *) context;
@@ -56,6 +72,22 @@ mono_mach_arch_mcontext_to_thread_state (mcontext_t context, thread_state_t stat
        *arch_state = ctx->__ss;
 }
 
+void
+mono_mach_arch_thread_state_to_mono_context (thread_state_t state, MonoContext *context)
+{
+       x86_thread_state32_t *arch_state = (x86_thread_state32_t *) state;
+       context->eax = arch_state->__eax;
+       context->ebx = arch_state->__ebx;
+       context->ecx = arch_state->__ecx;
+       context->edx = arch_state->__edx;
+       context->ebp = arch_state->__ebp;
+       context->esp = arch_state->__esp;
+       context->esi = arch_state->__edi;
+       context->edi = arch_state->__esi;
+       context->eip = arch_state->__eip;
+}
+
+
 int
 mono_mach_arch_get_thread_state_size ()
 {
@@ -65,31 +97,39 @@ mono_mach_arch_get_thread_state_size ()
 kern_return_t
 mono_mach_arch_get_thread_state (thread_port_t thread, thread_state_t state, mach_msg_type_number_t *count)
 {
+#if defined(HOST_WATCHOS)
+       g_error ("thread_get_state() is not supported by this platform");
+#else
        x86_thread_state32_t *arch_state = (x86_thread_state32_t *) state;
        kern_return_t ret;
 
        *count = x86_THREAD_STATE32_COUNT;
-
        ret = thread_get_state (thread, x86_THREAD_STATE32, (thread_state_t) arch_state, count);
 
        return ret;
+#endif
 }
 
 kern_return_t
 mono_mach_arch_set_thread_state (thread_port_t thread, thread_state_t state, mach_msg_type_number_t count)
 {
+#if defined(HOST_WATCHOS)
+       g_error ("thread_set_state() is not supported by this platform");
+#else
        return thread_set_state (thread, x86_THREAD_STATE32, state, count);
+#endif 
 }
 
 void *
 mono_mach_get_tls_address_from_thread (pthread_t thread, pthread_key_t key)
 {
        /* OSX stores TLS values in a hidden array inside the pthread_t structure
-        * They are keyed off a giant array offset 0x48 into the pointer.  This value
+        * They are keyed off a giant array from a known offset into the pointer.  This value
         * is baked into their pthread_getspecific implementation
         */
        intptr_t *p = (intptr_t *) thread;
-       intptr_t **tsd = (intptr_t **) ((char*)p + 0x48);
+       intptr_t **tsd = (intptr_t **) ((char*)p + tls_vector_offset);
+       g_assert (tls_vector_offset != -1);
 
        return (void *) &tsd [key];     
 }
@@ -100,5 +140,44 @@ mono_mach_arch_get_tls_value_from_thread (pthread_t thread, guint32 key)
        return *(void**)mono_mach_get_tls_address_from_thread (thread, key);
 }
 
+void
+mono_mach_init (pthread_key_t key)
+{
+       int i;
+       void *old_value = pthread_getspecific (key);
+       void *canary = (void*)0xDEADBEEFu;
+
+       pthread_key_create (&key, NULL);
+       g_assert (old_value != canary);
+
+       pthread_setspecific (key, canary);
+
+       /*First we probe for cats*/
+       tls_vector_offset = TLS_VECTOR_OFFSET_CATS;
+       if (mono_mach_arch_get_tls_value_from_thread (pthread_self (), key) == canary)
+               goto ok;
+
+       tls_vector_offset = TLS_VECTOR_OFFSET_10_9;
+       if (mono_mach_arch_get_tls_value_from_thread (pthread_self (), key) == canary)
+               goto ok;
+
+       tls_vector_offset = TLS_VECTOR_OFFSET_10_11;
+       if (mono_mach_arch_get_tls_value_from_thread (pthread_self (), key) == canary)
+               goto ok;
+
+       /*Fallback to scanning a large range of offsets*/
+       for (i = TLS_PROBE_LOW_WATERMARK; i <= TLS_PROBE_HIGH_WATERMARK; i += 4) {
+               tls_vector_offset = i;
+               if (mono_mach_arch_get_tls_value_from_thread (pthread_self (), key) == canary) {
+                       g_warning ("Found new TLS offset at %d", i);
+                       goto ok;
+               }
+       }
+
+       tls_vector_offset = -1;
+       g_warning ("could not discover the mach TLS offset");
+ok:
+       pthread_setspecific (key, old_value);
+}
 
 #endif