2 * tramp-x86.c: JIT trampoline code for x86
5 * Dietmar Maurer (dietmar@ximian.com)
7 * (C) 2001 Ximian, Inc.
13 #include <mono/metadata/appdomain.h>
14 #include <mono/metadata/metadata-internals.h>
15 #include <mono/metadata/marshal.h>
16 #include <mono/metadata/tabledefs.h>
17 #include <mono/metadata/mono-debug.h>
18 #include <mono/metadata/mono-debug-debugger.h>
19 #include <mono/arch/x86/x86-codegen.h>
21 #ifdef HAVE_VALGRIND_MEMCHECK_H
22 #include <valgrind/memcheck.h>
28 static guint8* nullified_class_init_trampoline;
31 * mono_arch_get_unbox_trampoline:
33 * @addr: pointer to native code for @m
35 * when value type methods are called through the vtable we need to unbox the
36 * this argument. This method returns a pointer to a trampoline which does
37 * unboxing before calling the method
40 mono_arch_get_unbox_trampoline (MonoMethod *m, gpointer addr)
44 MonoDomain *domain = mono_domain_get ();
46 if (!mono_method_signature (m)->ret->byref && MONO_TYPE_ISSTRUCT (mono_method_signature (m)->ret))
49 mono_domain_lock (domain);
50 start = code = mono_code_manager_reserve (domain->code_mp, 16);
51 mono_domain_unlock (domain);
53 x86_alu_membase_imm (code, X86_ADD, X86_ESP, this_pos, sizeof (MonoObject));
54 x86_jump_code (code, addr);
55 g_assert ((code - start) < 16);
61 mono_arch_patch_callsite (guint8 *orig_code, guint8 *addr)
65 gboolean can_write = mono_debugger_remove_breakpoints_from_code (orig_code - 8, buf, sizeof (buf));
69 if (mono_running_on_valgrind ())
72 /* go to the start of the call instruction
74 * address_byte = (m << 6) | (o << 3) | reg
75 * call opcode: 0xff address_byte displacement
81 if ((code [1] == 0xe8)) {
83 InterlockedExchange ((gint32*)(orig_code + 2), (guint)addr - ((guint)orig_code + 1) - 5);
85 #ifdef HAVE_VALGRIND_MEMCHECK_H
86 /* Tell valgrind to recompile the patched code */
87 //VALGRIND_DISCARD_TRANSLATIONS (code + 2, code + 6);
90 } else if (code [1] == 0xe9) {
91 /* A PLT entry: jmp <DISP> */
93 InterlockedExchange ((gint32*)(orig_code + 2), (guint)addr - ((guint)orig_code + 1) - 5);
95 printf ("Invalid trampoline sequence: %x %x %x %x %x %x %x\n", code [0], code [1], code [2], code [3],
96 code [4], code [5], code [6]);
97 g_assert_not_reached ();
102 mono_arch_patch_plt_entry (guint8 *code, guint8 *addr)
104 /* A PLT entry: jmp <DISP> */
105 g_assert (code [0] == 0xe9);
107 if (!mono_running_on_valgrind ())
108 InterlockedExchange ((gint32*)(code + 1), (guint)addr - (guint)code - 5);
112 mono_arch_nullify_class_init_trampoline (guint8 *code, gssize *regs)
115 if (code [0] == 0xe8) {
116 if (!mono_running_on_valgrind ()) {
119 * Thread safe code patching using the algorithm from the paper
120 * 'Practicing JUDO: Java Under Dynamic Optimizations'
123 * First atomically change the the first 2 bytes of the call to a
127 InterlockedExchange ((gint32*)code, ops);
129 /* Then change the other bytes to a nop */
134 /* Then atomically change the first 4 bytes to a nop as well */
136 InterlockedExchange ((gint32*)code, ops);
137 #ifdef HAVE_VALGRIND_MEMCHECK_H
138 /* FIXME: the calltree skin trips on the self modifying code above */
140 /* Tell valgrind to recompile the patched code */
141 //VALGRIND_DISCARD_TRANSLATIONS (code, code + 8);
144 } else if (code [0] == 0x90 || code [0] == 0xeb) {
145 /* Already changed by another thread */
147 } else if ((code [-1] == 0xff) && (x86_modrm_reg (code [0]) == 0x2)) {
148 /* call *<OFFSET>(<REG>) -> Call made from AOT code */
149 gpointer *vtable_slot;
151 vtable_slot = mono_arch_get_vcall_slot_addr (code + 5, (gpointer*)regs);
152 g_assert (vtable_slot);
154 *vtable_slot = nullified_class_init_trampoline;
156 printf ("Invalid trampoline sequence: %x %x %x %x %x %x %x\n", code [0], code [1], code [2], code [3],
157 code [4], code [5], code [6]);
158 g_assert_not_reached ();
163 mono_arch_nullify_plt_entry (guint8 *code)
165 if (!mono_running_on_valgrind ()) {
169 InterlockedExchange ((gint32*)code, ops);
171 /* Then change the other bytes to a nop */
176 /* Change the first byte to a nop */
178 InterlockedExchange ((gint32*)code, ops);
183 mono_arch_create_trampoline_code (MonoTrampolineType tramp_type)
188 code = buf = mono_global_codeman_reserve (256);
190 /* Note that there is a single argument to the trampoline
191 * and it is stored at: esp + pushed_args * sizeof (gpointer)
192 * the ret address is at: esp + (pushed_args + 1) * sizeof (gpointer)
194 /* Put all registers into an array on the stack
195 * If this code is changed, make sure to update the offset value in
196 * mono_arch_find_this_argument () in mini-x86.c.
198 x86_push_reg (buf, X86_EDI);
199 x86_push_reg (buf, X86_ESI);
200 x86_push_reg (buf, X86_EBP);
201 x86_push_reg (buf, X86_ESP);
202 x86_push_reg (buf, X86_EBX);
203 x86_push_reg (buf, X86_EDX);
204 x86_push_reg (buf, X86_ECX);
205 x86_push_reg (buf, X86_EAX);
209 /* Align stack on apple */
210 x86_alu_reg_imm (buf, X86_SUB, X86_ESP, 4);
216 /* save the IP (caller ip) */
217 if (tramp_type == MONO_TRAMPOLINE_JUMP)
218 x86_push_imm (buf, 0);
220 x86_push_membase (buf, X86_ESP, (pushed_args + 1) * sizeof (gpointer));
224 x86_push_reg (buf, X86_EBP);
225 x86_push_reg (buf, X86_ESI);
226 x86_push_reg (buf, X86_EDI);
227 x86_push_reg (buf, X86_EBX);
232 x86_push_reg (buf, X86_ESP);
233 /* Adjust ESP so it points to the previous frame */
234 x86_alu_membase_imm (buf, X86_ADD, X86_ESP, 0, (pushed_args + 2) * 4);
238 /* save method info */
239 if ((tramp_type == MONO_TRAMPOLINE_GENERIC) || (tramp_type == MONO_TRAMPOLINE_JUMP))
240 x86_push_membase (buf, X86_ESP, pushed_args * sizeof (gpointer));
242 x86_push_imm (buf, 0);
246 /* On apple, the stack is correctly aligned to 16 bytes because pushed_args is
247 * 16 and there is the extra trampoline arg + the return ip pushed by call
248 * FIXME: Note that if an exception happens while some args are pushed
249 * on the stack, the stack will be misaligned.
251 g_assert (pushed_args == 16);
253 /* get the address of lmf for the current thread */
254 x86_call_code (buf, mono_get_lmf_addr);
256 x86_push_reg (buf, X86_EAX);
257 /* push *lfm (previous_lmf) */
258 x86_push_membase (buf, X86_EAX, 0);
259 /* Signal to mono_arch_find_jit_info () that this is a trampoline frame */
260 x86_alu_membase_imm (buf, X86_ADD, X86_ESP, 0, 1);
262 x86_mov_membase_reg (buf, X86_EAX, 0, X86_ESP, 4);
267 /* starting the call sequence */
269 /* FIXME: Push the trampoline address */
270 x86_push_imm (buf, 0);
274 /* push the method info */
275 x86_push_membase (buf, X86_ESP, pushed_args * sizeof (gpointer));
279 /* push the return address onto the stack */
280 if (tramp_type == MONO_TRAMPOLINE_JUMP)
281 x86_push_imm (buf, 0);
283 x86_push_membase (buf, X86_ESP, (pushed_args + 1) * sizeof (gpointer));
285 /* push the address of the register array */
286 x86_lea_membase (buf, X86_EAX, X86_ESP, (pushed_args - 8) * sizeof (gpointer));
287 x86_push_reg (buf, X86_EAX);
292 /* check the stack is aligned after the ret ip is pushed */
293 /*x86_mov_reg_reg (buf, X86_EDX, X86_ESP, 4);
294 x86_alu_reg_imm (buf, X86_AND, X86_EDX, 15);
295 x86_alu_reg_imm (buf, X86_CMP, X86_EDX, 0);
296 x86_branch_disp (buf, X86_CC_Z, 3, FALSE);
297 x86_breakpoint (buf);*/
300 if (tramp_type == MONO_TRAMPOLINE_CLASS_INIT)
301 x86_call_code (buf, mono_class_init_trampoline);
302 else if (tramp_type == MONO_TRAMPOLINE_AOT)
303 x86_call_code (buf, mono_aot_trampoline);
304 else if (tramp_type == MONO_TRAMPOLINE_AOT_PLT)
305 x86_call_code (buf, mono_aot_plt_trampoline);
306 else if (tramp_type == MONO_TRAMPOLINE_DELEGATE)
307 x86_call_code (buf, mono_delegate_trampoline);
309 x86_call_code (buf, mono_magic_trampoline);
311 x86_alu_reg_imm (buf, X86_ADD, X86_ESP, 4*4);
313 /* restore LMF start */
314 /* ebx = previous_lmf */
315 x86_pop_reg (buf, X86_EBX);
316 x86_alu_reg_imm (buf, X86_SUB, X86_EBX, 1);
318 x86_pop_reg (buf, X86_EDI);
319 /* *(lmf) = previous_lmf */
320 x86_mov_membase_reg (buf, X86_EDI, 0, X86_EBX, 4);
321 /* discard method info */
322 x86_pop_reg (buf, X86_ESI);
324 x86_pop_reg (buf, X86_ESI);
325 /* restore caller saved regs */
326 x86_pop_reg (buf, X86_EBX);
327 x86_pop_reg (buf, X86_EDI);
328 x86_pop_reg (buf, X86_ESI);
329 x86_pop_reg (buf, X86_EBP);
331 /* discard save IP */
332 x86_alu_reg_imm (buf, X86_ADD, X86_ESP, 4);
333 /* restore LMF end */
335 /* Restore caller saved registers */
336 x86_mov_reg_membase (buf, X86_ECX, X86_ESP, 1 * 4, 4);
337 x86_mov_reg_membase (buf, X86_EDX, X86_ESP, 2 * 4, 4);
339 /* Pop saved reg array + stack align + method ptr */
340 x86_alu_reg_imm (buf, X86_ADD, X86_ESP, 10 * 4);
342 if (tramp_type == MONO_TRAMPOLINE_CLASS_INIT)
345 /* call the compiled method */
346 x86_jump_reg (buf, X86_EAX);
348 g_assert ((buf - code) <= 256);
350 if (tramp_type == MONO_TRAMPOLINE_CLASS_INIT) {
351 /* Initialize the nullified class init trampoline used in the AOT case */
352 nullified_class_init_trampoline = buf = mono_global_codeman_reserve (16);
359 #define TRAMPOLINE_SIZE 10
362 mono_arch_create_specific_trampoline (gpointer arg1, MonoTrampolineType tramp_type, MonoDomain *domain, guint32 *code_len)
364 guint8 *code, *buf, *tramp;
366 tramp = mono_get_trampoline_code (tramp_type);
368 mono_domain_lock (domain);
369 code = buf = mono_code_manager_reserve_align (domain->code_mp, TRAMPOLINE_SIZE, 4);
370 mono_domain_unlock (domain);
372 x86_push_imm (buf, arg1);
373 x86_jump_code (buf, tramp);
374 g_assert ((buf - code) <= TRAMPOLINE_SIZE);
376 mono_arch_flush_icache (code, buf - code);
379 *code_len = buf - code;
385 mono_arch_invalidate_method (MonoJitInfo *ji, void *func, gpointer func_arg)
387 /* FIXME: This is not thread safe */
388 guint8 *code = ji->code_start;
390 x86_push_imm (code, func_arg);
391 x86_call_code (code, (guint8*)func);
395 * This method is only called when running in the Mono Debugger.
398 mono_debugger_create_notification_function (void)
402 code = buf = mono_global_codeman_reserve (2);
403 x86_breakpoint (buf);