2 * mach-support-x86.c: mach support for x86
5 * Geoff Norton (gnorton@novell.com)
7 * (C) 2010 Novell, Inc.
16 #include "utils/mono-sigcontext.h"
17 #include "mach-support.h"
19 /* Known offsets used for TLS storage*/
21 /* All OSX versions up to 10.8 */
22 #define TLS_VECTOR_OFFSET_CATS 0x48
23 #define TLS_VECTOR_OFFSET_10_9 0xb0
24 #define TLS_VECTOR_OFFSET_10_11 0x100
27 /* This is 2 slots less than the known low */
28 #define TLS_PROBE_LOW_WATERMARK 0x40
29 /* This is 28 slots above the know high, which is more than the known high-low*/
30 #define TLS_PROBE_HIGH_WATERMARK 0x120
33 static int tls_vector_offset;
36 mono_mach_arch_get_ip (thread_state_t state)
38 x86_thread_state32_t *arch_state = (x86_thread_state32_t *) state;
40 return (void *) arch_state->__eip;
44 mono_mach_arch_get_sp (thread_state_t state)
46 x86_thread_state32_t *arch_state = (x86_thread_state32_t *) state;
48 return (void *) arch_state->__esp;
52 mono_mach_arch_get_mcontext_size ()
54 return sizeof (struct __darwin_mcontext32);
58 mono_mach_arch_thread_state_to_mcontext (thread_state_t state, void *context)
60 x86_thread_state32_t *arch_state = (x86_thread_state32_t *) state;
61 struct __darwin_mcontext32 *ctx = (struct __darwin_mcontext32 *) context;
63 ctx->__ss = *arch_state;
67 mono_mach_arch_mcontext_to_thread_state (void *context, thread_state_t state)
69 x86_thread_state32_t *arch_state = (x86_thread_state32_t *) state;
70 struct __darwin_mcontext32 *ctx = (struct __darwin_mcontext32 *) context;
72 *arch_state = ctx->__ss;
76 mono_mach_arch_get_thread_state_size ()
78 return sizeof (x86_thread_state32_t);
82 mono_mach_arch_get_thread_state (thread_port_t thread, thread_state_t state, mach_msg_type_number_t *count)
84 x86_thread_state32_t *arch_state = (x86_thread_state32_t *) state;
87 *count = x86_THREAD_STATE32_COUNT;
89 ret = thread_get_state (thread, x86_THREAD_STATE32, (thread_state_t) arch_state, count);
95 mono_mach_arch_set_thread_state (thread_port_t thread, thread_state_t state, mach_msg_type_number_t count)
97 return thread_set_state (thread, x86_THREAD_STATE32, state, count);
101 mono_mach_get_tls_address_from_thread (pthread_t thread, pthread_key_t key)
103 /* OSX stores TLS values in a hidden array inside the pthread_t structure
104 * They are keyed off a giant array from a known offset into the pointer. This value
105 * is baked into their pthread_getspecific implementation
107 intptr_t *p = (intptr_t *) thread;
108 intptr_t **tsd = (intptr_t **) ((char*)p + tls_vector_offset);
109 g_assert (tls_vector_offset != -1);
111 return (void *) &tsd [key];
115 mono_mach_arch_get_tls_value_from_thread (pthread_t thread, guint32 key)
117 return *(void**)mono_mach_get_tls_address_from_thread (thread, key);
121 mono_mach_init (pthread_key_t key)
124 void *old_value = pthread_getspecific (key);
125 void *canary = (void*)0xDEADBEEFu;
127 pthread_key_create (&key, NULL);
128 g_assert (old_value != canary);
130 pthread_setspecific (key, canary);
132 /*First we probe for cats*/
133 tls_vector_offset = TLS_VECTOR_OFFSET_CATS;
134 if (mono_mach_arch_get_tls_value_from_thread (pthread_self (), key) == canary)
137 tls_vector_offset = TLS_VECTOR_OFFSET_10_9;
138 if (mono_mach_arch_get_tls_value_from_thread (pthread_self (), key) == canary)
141 tls_vector_offset = TLS_VECTOR_OFFSET_10_11;
142 if (mono_mach_arch_get_tls_value_from_thread (pthread_self (), key) == canary)
145 tls_vector_offset = TLS_VECTOR_OFFSET_10_11;
146 if (mono_mach_arch_get_tls_value_from_thread (pthread_self (), key) == canary)
149 /*Fallback to scanning a large range of offsets*/
150 for (i = TLS_PROBE_LOW_WATERMARK; i <= TLS_PROBE_HIGH_WATERMARK; i += 4) {
151 tls_vector_offset = i;
152 if (mono_mach_arch_get_tls_value_from_thread (pthread_self (), key) == canary) {
153 g_warning ("Found new TLS offset at %d", i);
158 tls_vector_offset = -1;
159 g_warning ("could not discover the mach TLS offset");
161 pthread_setspecific (key, old_value);