1 /* src/vm/jit/patcher-common.cpp - architecture independent code patching stuff
3 Copyright (C) 2007, 2008
4 CACAOVM - Verein zur Foerderung der freien virtuellen Maschine CACAO
5 Copyright (C) 2008 Theobroma Systems Ltd.
7 This file is part of CACAO.
9 This program is free software; you can redistribute it and/or
10 modify it under the terms of the GNU General Public License as
11 published by the Free Software Foundation; either version 2, or (at
12 your option) any later version.
14 This program is distributed in the hope that it will be useful, but
15 WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program; if not, write to the Free Software
21 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
35 #include "codegen.h" /* for PATCHER_NOPS */
39 #include "mm/memory.hpp"
41 #include "native/native.hpp"
43 #include "toolbox/list.hpp"
44 #include "toolbox/logging.hpp" /* XXX remove me! */
46 #include "vm/exceptions.hpp"
47 #include "vm/initialize.hpp"
48 #include "vm/options.h"
49 #include "vm/resolve.hpp"
50 #include "vm/vm.hpp" /* for vm_abort */
52 #include "vm/jit/code.hpp"
53 #include "vm/jit/disass.h"
54 #include "vm/jit/jit.hpp"
55 #include "vm/jit/patcher-common.hpp"
58 /* patcher_function_list *******************************************************
60 This is a list which maps patcher function pointers to the according
61 names of the patcher functions. It is only usefull for debugging
64 *******************************************************************************/
67 typedef struct patcher_function_list_t {
70 } patcher_function_list_t;
72 static patcher_function_list_t patcher_function_list[] = {
73 { PATCHER_initialize_class, "initialize_class" },
74 #ifdef ENABLE_VERIFIER
75 { PATCHER_resolve_class, "resolve_class" },
76 #endif /* ENABLE_VERIFIER */
77 { PATCHER_resolve_native_function, "resolve_native_function" },
78 { PATCHER_invokestatic_special, "invokestatic_special" },
79 { PATCHER_invokevirtual, "invokevirtual" },
80 { PATCHER_invokeinterface, "invokeinterface" },
81 { NULL, "-UNKNOWN PATCHER FUNCTION-" }
86 /* patcher_list_create *********************************************************
88 Creates an empty patcher list for the given codeinfo.
90 *******************************************************************************/
92 void patcher_list_create(codeinfo *code)
94 code->patchers = new LockedList<patchref_t>();
98 /* patcher_list_reset **********************************************************
100 Resets the patcher list inside a codeinfo. This is usefull when
101 resetting a codeinfo for recompiling.
103 *******************************************************************************/
105 void patcher_list_reset(codeinfo *code)
107 #if defined(ENABLE_STATISTICS)
109 size_patchref -= sizeof(patchref_t) * code->patchers->size();
112 // Free all elements of the list.
113 code->patchers->clear();
116 /* patcher_list_free ***********************************************************
118 Frees the patcher list and all its entries for the given codeinfo.
120 *******************************************************************************/
122 void patcher_list_free(codeinfo *code)
124 // Free all elements of the list.
125 patcher_list_reset(code);
127 // Free the list itself.
128 delete code->patchers;
133 * Find an entry inside the patcher list for the given codeinfo by
134 * specifying the program counter of the patcher position.
136 * NOTE: Caller should hold the patcher list lock or maintain
137 * exclusive access otherwise.
139 * @param pc Program counter to find.
141 * @return Pointer to patcher.
144 struct foo : public std::binary_function<patchref_t, void*, bool> {
145 bool operator() (const patchref_t& pr, const void* pc) const
147 return (pr.mpc == (uintptr_t) pc);
151 static patchref_t* patcher_list_find(codeinfo* code, void* pc)
153 // Search for a patcher with the given PC.
154 List<patchref_t>::iterator it = std::find_if(code->patchers->begin(), code->patchers->end(), std::bind2nd(foo(), pc));
156 if (it == code->patchers->end())
163 /* patcher_add_patch_ref *******************************************************
165 Appends a new patcher reference to the list of patching positions.
167 *******************************************************************************/
169 void patcher_add_patch_ref(jitdata *jd, functionptr patcher, void* ref, s4 disp)
177 patchmpc = cd->mcodeptr - cd->mcodebase;
179 #if defined(ALIGN_PATCHER_TRAP)
180 emit_patcher_alignment(cd);
181 patchmpc = cd->mcodeptr - cd->mcodebase;
185 if (patcher_list_find(code, (void*) (intptr_t) patchmpc) != NULL)
186 vm_abort("patcher_add_patch_ref: different patchers at same position.");
189 // Set patcher information (mpc is resolved later).
195 pr.patcher = patcher;
200 // Store patcher in the list (NOTE: structure is copied).
201 code->patchers->push_back(pr);
203 #if defined(ENABLE_STATISTICS)
205 size_patchref += sizeof(patchref_t);
208 #if defined(ENABLE_JIT) && (defined(__I386__) || defined(__M68K__) || defined(__SPARC_64__) || defined(__X86_64__))
210 /* XXX We can remove that when we don't use UD2 anymore on i386
213 /* On some architectures the patcher stub call instruction might
214 be longer than the actual instruction generated. On this
215 architectures we store the last patcher call position and after
216 the basic block code generation is completed, we check the
217 range and maybe generate some nop's. */
218 /* The nops are generated in codegen_emit in each codegen */
220 cd->lastmcodeptr = cd->mcodeptr + PATCHER_CALL_SIZE;
226 * Resolve all patchers in the current JIT run.
228 * @param jd JIT data-structure
230 void patcher_resolve(jitdata* jd)
232 // Get required compiler data.
233 codeinfo* code = jd->code;
235 for (List<patchref_t>::iterator it = code->patchers->begin(); it != code->patchers->end(); it++) {
236 patchref_t& pr = *it;
238 pr.mpc += (intptr_t) code->entrypoint;
239 pr.datap = (intptr_t) (pr.disp + code->entrypoint);
245 * Check if the patcher is already patched. This is done by comparing
246 * the machine instruction.
248 * @param pr Patcher structure.
250 * @return true if patched, false otherwise.
252 bool patcher_is_patched(patchref_t* pr)
254 // Validate the instruction at the patching position is the same
255 // instruction as the patcher structure contains.
256 uint32_t mcode = *((uint32_t*) pr->mpc);
258 #if PATCHER_CALL_SIZE == 4
259 if (mcode != pr->mcode) {
260 #elif PATCHER_CALL_SIZE == 2
261 if ((uint16_t) mcode != (uint16_t) pr->mcode) {
263 #error Unknown PATCHER_CALL_SIZE
276 bool patcher_is_patched_at(void* pc)
278 codeinfo* code = code_find_codeinfo_for_pc(pc);
280 // Get the patcher for the given PC.
281 patchref_t* pr = patcher_list_find(code, pc);
284 // The given PC is not a patcher position.
288 // Validate the instruction.
289 return patcher_is_patched(pr);
293 /* patcher_handler *************************************************************
295 Handles the request to patch JIT code at the given patching
296 position. This function is normally called by the signal
299 NOTE: The patcher list lock is used to maintain exclusive
300 access of the patched position (in fact of the whole code).
301 After patching has suceeded, the patcher reference should be
302 removed from the patcher list to avoid double patching.
304 *******************************************************************************/
307 /* XXX this indent is not thread safe! */
308 /* XXX if you want it thread safe, place patcher_depth in threadobject! */
309 static int patcher_depth = 0;
310 #define TRACE_PATCHER_INDENT for (i=0; i<patcher_depth; i++) printf("\t")
311 #endif /* !defined(NDEBUG) */
313 java_handle_t *patcher_handler(u1 *pc)
319 patcher_function_list_t *l;
323 /* define the patcher function */
325 bool (*patcher_function)(patchref_t *);
327 /* search the codeinfo for the given PC */
329 code = code_find_codeinfo_for_pc(pc);
332 // Enter a mutex on the patcher list.
333 code->patchers->lock();
335 /* search the patcher information for the given PC */
337 pr = patcher_list_find(code, pc);
340 vm_abort("patcher_handler: Unable to find patcher reference.");
344 if (opt_DebugPatcher) {
345 log_println("patcher_handler: double-patching detected!");
348 code->patchers->unlock();
353 if (opt_DebugPatcher) {
354 for (l = patcher_function_list; l->patcher != NULL; l++)
355 if (l->patcher == pr->patcher)
358 TRACE_PATCHER_INDENT; printf("patching in "); method_print(code->m); printf(" at %p\n", (void *) pr->mpc);
359 TRACE_PATCHER_INDENT; printf("\tpatcher function = %s <%p>\n", l->name, (void *) (intptr_t) pr->patcher);
361 TRACE_PATCHER_INDENT;
362 printf("\tmachine code before = ");
364 # if defined(ENABLE_DISASSEMBLER)
365 disassinstr((u1*) (void*) pr->mpc);
367 printf("%x at %p (disassembler disabled)\n", *((uint32_t*) pr->mpc), (void*) pr->mpc);
371 assert(patcher_depth > 0);
375 /* cast the passed function to a patcher function */
377 patcher_function = (bool (*)(patchref_t *)) (ptrint) pr->patcher;
379 /* call the proper patcher function */
381 result = (patcher_function)(pr);
384 if (opt_DebugPatcher) {
385 assert(patcher_depth > 0);
388 TRACE_PATCHER_INDENT;
389 printf("\tmachine code after = ");
391 # if defined(ENABLE_DISASSEMBLER)
392 disassinstr((u1*) (void*) pr->mpc);
394 printf("%x at %p (disassembler disabled)\n", *((uint32_t*) pr->mpc), (void*) pr->mpc);
397 if (result == false) {
398 TRACE_PATCHER_INDENT; printf("\tPATCHER EXCEPTION!\n");
403 // Check for return value and exit accordingly.
404 if (result == false) {
405 // Mangle the pending exception.
406 resolve_handle_pending_exception(true);
408 // Get the exception and return it.
409 java_handle_t* e = exceptions_get_and_clear_exception();
411 code->patchers->unlock();
416 pr->done = true; /* XXX this is only preliminary to prevent double-patching */
418 code->patchers->unlock();
424 /* patcher_initialize_class ****************************************************
426 Initalizes a given classinfo pointer.
427 This function does not patch any data.
429 *******************************************************************************/
431 bool patcher_initialize_class(patchref_t *pr)
435 /* get stuff from the patcher reference */
437 c = (classinfo *) pr->ref;
439 /* check if the class is initialized */
441 if (!(c->state & CLASS_INITIALIZED))
442 if (!initialize_class(c))
445 /* patch back original code */
447 patcher_patch_code(pr);
453 /* patcher_resolve_class *******************************************************
455 Resolves a given unresolved class reference.
456 This function does not patch any data.
458 *******************************************************************************/
460 #ifdef ENABLE_VERIFIER
461 bool patcher_resolve_class(patchref_t *pr)
463 unresolved_class *uc;
465 /* get stuff from the patcher reference */
467 uc = (unresolved_class *) pr->ref;
469 /* resolve the class and check subtype constraints */
471 if (!resolve_class_eager_no_access_check(uc))
474 /* patch back original code */
476 patcher_patch_code(pr);
480 #endif /* ENABLE_VERIFIER */
483 /* patcher_resolve_native_function *********************************************
485 Resolves the native function for a given methodinfo.
486 This function patches one data segment word.
488 *******************************************************************************/
490 bool patcher_resolve_native_function(patchref_t *pr)
495 /* get stuff from the patcher reference */
497 m = (methodinfo *) pr->ref;
498 datap = (uint8_t *) pr->datap;
500 /* resolve native function */
502 NativeMethods& nm = VM::get_current()->get_nativemethods();
503 void* f = nm.resolve_method(m);
508 /* patch native function pointer */
510 *((intptr_t*) datap) = (intptr_t) f;
512 /* synchronize data cache */
514 md_dcacheflush(datap, SIZEOF_VOID_P);
516 /* patch back original code */
518 patcher_patch_code(pr);
525 * These are local overrides for various environment variables in Emacs.
526 * Please do not remove this and leave it at the end of the file, where
527 * Emacs will automagically detect them.
528 * ---------------------------------------------------------------------
531 * indent-tabs-mode: t
535 * vim:noexpandtab:sw=4:ts=4: