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 */
38 #include "mm/memory.h"
40 #include "native/native.h"
42 #include "toolbox/list.hpp"
43 #include "toolbox/logging.h" /* XXX remove me! */
45 #include "vm/exceptions.hpp"
46 #include "vm/initialize.h"
47 #include "vm/options.h"
48 #include "vm/resolve.h"
49 #include "vm/vm.hpp" /* for vm_abort */
51 #include "vm/jit/code.hpp"
52 #include "vm/jit/disass.h"
53 #include "vm/jit/jit.hpp"
54 #include "vm/jit/patcher-common.hpp"
57 /* patcher_function_list *******************************************************
59 This is a list which maps patcher function pointers to the according
60 names of the patcher functions. It is only usefull for debugging
63 *******************************************************************************/
66 typedef struct patcher_function_list_t {
69 } patcher_function_list_t;
71 static patcher_function_list_t patcher_function_list[] = {
72 { PATCHER_initialize_class, "initialize_class" },
73 { PATCHER_resolve_class, "resolve_class" },
74 { PATCHER_resolve_native_function, "resolve_native_function" },
75 { PATCHER_invokestatic_special, "invokestatic_special" },
76 { PATCHER_invokevirtual, "invokevirtual" },
77 { PATCHER_invokeinterface, "invokeinterface" },
78 { NULL, "-UNKNOWN PATCHER FUNCTION-" }
83 /* patcher_list_create *********************************************************
85 Creates an empty patcher list for the given codeinfo.
87 *******************************************************************************/
89 void patcher_list_create(codeinfo *code)
91 code->patchers = new List<patchref_t>();
95 /* patcher_list_reset **********************************************************
97 Resets the patcher list inside a codeinfo. This is usefull when
98 resetting a codeinfo for recompiling.
100 *******************************************************************************/
102 void patcher_list_reset(codeinfo *code)
104 #if defined(ENABLE_STATISTICS)
106 size_patchref -= sizeof(patchref_t) * code->patchers->size();
109 // Free all elements of the list.
110 code->patchers->clear();
113 /* patcher_list_free ***********************************************************
115 Frees the patcher list and all its entries for the given codeinfo.
117 *******************************************************************************/
119 void patcher_list_free(codeinfo *code)
121 // Free all elements of the list.
122 patcher_list_reset(code);
124 // Free the list itself.
125 delete code->patchers;
130 * Find an entry inside the patcher list for the given codeinfo by
131 * specifying the program counter of the patcher position.
133 * NOTE: Caller should hold the patcher list lock or maintain
134 * exclusive access otherwise.
136 * @param pc Program counter to find.
138 * @return Pointer to patcher.
141 struct foo : public std::binary_function<patchref_t, void*, bool> {
142 bool operator() (const patchref_t& pr, const void* pc) const
144 return (pr.mpc == (uintptr_t) pc);
148 static patchref_t* patcher_list_find(codeinfo* code, void* pc)
150 // Search for a patcher with the given PC.
151 List<patchref_t>::iterator it = std::find_if(code->patchers->begin(), code->patchers->end(), std::bind2nd(foo(), pc));
153 if (it == code->patchers->end())
160 /* patcher_add_patch_ref *******************************************************
162 Appends a new patcher reference to the list of patching positions.
164 *******************************************************************************/
166 void patcher_add_patch_ref(jitdata *jd, functionptr patcher, void* ref, s4 disp)
174 patchmpc = cd->mcodeptr - cd->mcodebase;
177 if (patcher_list_find(code, (void*) (intptr_t) patchmpc) != NULL)
178 vm_abort("patcher_add_patch_ref: different patchers at same position.");
181 // Set patcher information (mpc is resolved later).
186 pr.patcher = patcher;
191 // Store patcher in the list (NOTE: structure is copied).
192 code->patchers->push_back(pr);
194 #if defined(ENABLE_STATISTICS)
196 size_patchref += sizeof(patchref_t);
199 #if defined(ENABLE_JIT) && (defined(__I386__) || defined(__M68K__) || defined(__SPARC_64__) || defined(__X86_64__))
201 /* XXX We can remove that when we don't use UD2 anymore on i386
204 /* On some architectures the patcher stub call instruction might
205 be longer than the actual instruction generated. On this
206 architectures we store the last patcher call position and after
207 the basic block code generation is completed, we check the
208 range and maybe generate some nop's. */
209 /* The nops are generated in codegen_emit in each codegen */
211 cd->lastmcodeptr = cd->mcodeptr + PATCHER_CALL_SIZE;
217 * Resolve all patchers in the current JIT run.
219 * @param jd JIT data-structure
221 void patcher_resolve(jitdata* jd)
223 // Get required compiler data.
224 codeinfo* code = jd->code;
226 for (List<patchref_t>::iterator it = code->patchers->begin(); it != code->patchers->end(); it++) {
227 patchref_t& pr = *it;
229 pr.mpc += (intptr_t) code->entrypoint;
230 pr.datap = (intptr_t) (pr.disp + code->entrypoint);
236 * Check if the patcher is already patched. This is done by comparing
237 * the machine instruction.
239 * @param pr Patcher structure.
241 * @return true if patched, false otherwise.
243 bool patcher_is_patched(patchref_t* pr)
245 // Validate the instruction at the patching position is the same
246 // instruction as the patcher structure contains.
247 uint32_t mcode = *((uint32_t*) pr->mpc);
249 if (mcode != pr->mcode) {
261 bool patcher_is_patched_at(void* pc)
263 codeinfo* code = code_find_codeinfo_for_pc(pc);
265 // Get the patcher for the given PC.
266 patchref_t* pr = patcher_list_find(code, pc);
269 // The given PC is not a patcher position.
273 // Validate the instruction.
274 return patcher_is_patched(pr);
278 /* patcher_handler *************************************************************
280 Handles the request to patch JIT code at the given patching
281 position. This function is normally called by the signal
284 NOTE: The patcher list lock is used to maintain exclusive
285 access of the patched position (in fact of the whole code).
286 After patching has suceeded, the patcher reference should be
287 removed from the patcher list to avoid double patching.
289 *******************************************************************************/
292 /* XXX this indent is not thread safe! */
293 /* XXX if you want it thread safe, place patcher_depth in threadobject! */
294 static int patcher_depth = 0;
295 #define TRACE_PATCHER_INDENT for (i=0; i<patcher_depth; i++) printf("\t")
296 #endif /* !defined(NDEBUG) */
298 java_handle_t *patcher_handler(u1 *pc)
305 patcher_function_list_t *l;
309 /* define the patcher function */
311 bool (*patcher_function)(patchref_t *);
313 /* search the codeinfo for the given PC */
315 code = code_find_codeinfo_for_pc(pc);
318 // Enter a mutex on the patcher list.
319 code->patchers->lock();
321 /* search the patcher information for the given PC */
323 pr = patcher_list_find(code, pc);
326 vm_abort("patcher_handler: Unable to find patcher reference.");
330 if (opt_DebugPatcher) {
331 log_println("patcher_handler: double-patching detected!");
334 code->patchers->unlock();
339 if (opt_DebugPatcher) {
340 for (l = patcher_function_list; l->patcher != NULL; l++)
341 if (l->patcher == pr->patcher)
344 TRACE_PATCHER_INDENT; printf("patching in "); method_print(code->m); printf(" at %p\n", (void *) pr->mpc);
345 TRACE_PATCHER_INDENT; printf("\tpatcher function = %s <%p>\n", l->name, (void *) (intptr_t) pr->patcher);
347 TRACE_PATCHER_INDENT;
348 printf("\tmachine code before = ");
350 # if defined(ENABLE_DISASSEMBLER)
351 disassinstr((u1*) (void*) pr->mpc);
353 printf("%x at %p (disassembler disabled)\n", *((uint32_t*) pr->mpc), (void*) pr->mpc);
357 assert(patcher_depth > 0);
361 /* cast the passed function to a patcher function */
363 patcher_function = (bool (*)(patchref_t *)) (ptrint) pr->patcher;
365 /* call the proper patcher function */
367 result = (patcher_function)(pr);
370 if (opt_DebugPatcher) {
371 assert(patcher_depth > 0);
374 TRACE_PATCHER_INDENT;
375 printf("\tmachine code after = ");
377 # if defined(ENABLE_DISASSEMBLER)
378 disassinstr((u1*) (void*) pr->mpc);
380 printf("%x at %p (disassembler disabled)\n", *((uint32_t*) pr->mpc), (void*) pr->mpc);
383 if (result == false) {
384 TRACE_PATCHER_INDENT; printf("\tPATCHER EXCEPTION!\n");
389 /* check for return value and exit accordingly */
391 if (result == false) {
392 e = exceptions_get_and_clear_exception();
394 code->patchers->unlock();
399 pr->done = true; /* XXX this is only preliminary to prevent double-patching */
401 code->patchers->unlock();
407 /* patcher_initialize_class ****************************************************
409 Initalizes a given classinfo pointer.
410 This function does not patch any data.
412 *******************************************************************************/
414 bool patcher_initialize_class(patchref_t *pr)
418 /* get stuff from the patcher reference */
420 c = (classinfo *) pr->ref;
422 /* check if the class is initialized */
424 if (!(c->state & CLASS_INITIALIZED))
425 if (!initialize_class(c))
428 /* patch back original code */
430 patcher_patch_code(pr);
436 /* patcher_resolve_class *******************************************************
438 Resolves a given unresolved class reference.
439 This function does not patch any data.
441 *******************************************************************************/
443 #ifdef ENABLE_VERIFIER
444 bool patcher_resolve_class(patchref_t *pr)
446 unresolved_class *uc;
448 /* get stuff from the patcher reference */
450 uc = (unresolved_class *) pr->ref;
452 /* resolve the class and check subtype constraints */
454 if (!resolve_class_eager_no_access_check(uc))
457 /* patch back original code */
459 patcher_patch_code(pr);
463 #endif /* ENABLE_VERIFIER */
466 /* patcher_resolve_native_function *********************************************
468 Resolves the native function for a given methodinfo.
469 This function patches one data segment word.
471 *******************************************************************************/
473 bool patcher_resolve_native_function(patchref_t *pr)
479 /* get stuff from the patcher reference */
481 m = (methodinfo *) pr->ref;
482 datap = (uint8_t *) pr->datap;
484 /* resolve native function */
486 if (!(f = native_method_resolve(m)))
489 /* patch native function pointer */
491 *((intptr_t *) datap) = (intptr_t) f;
493 /* synchronize data cache */
495 md_dcacheflush(datap, SIZEOF_VOID_P);
497 /* patch back original code */
499 patcher_patch_code(pr);
506 * These are local overrides for various environment variables in Emacs.
507 * Please do not remove this and leave it at the end of the file, where
508 * Emacs will automagically detect them.
509 * ---------------------------------------------------------------------
512 * indent-tabs-mode: t
516 * vim:noexpandtab:sw=4:ts=4: