1 /* src/vm/jit/patcher-common.c - 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
32 #include "codegen.h" /* for PATCHER_NOPS */
35 #include "mm/memory.h"
37 #include "native/native.h"
39 #include "threads/lock-common.h"
41 #include "toolbox/list.h"
42 #include "toolbox/logging.h" /* XXX remove me! */
44 #include "vm/exceptions.hpp"
45 #include "vm/initialize.h"
46 #include "vm/options.h"
47 #include "vm/resolve.h"
48 #include "vm/vm.hpp" /* for vm_abort */
50 #include "vm/jit/code.h"
51 #include "vm/jit/disass.h"
52 #include "vm/jit/jit.h"
53 #include "vm/jit/patcher-common.h"
56 /* patcher_function_list *******************************************************
58 This is a list which maps patcher function pointers to the according
59 names of the patcher functions. It is only usefull for debugging
62 *******************************************************************************/
65 typedef struct patcher_function_list_t {
68 } patcher_function_list_t;
70 static patcher_function_list_t patcher_function_list[] = {
71 { PATCHER_initialize_class, "initialize_class" },
72 { PATCHER_resolve_class, "resolve_class" },
73 { PATCHER_resolve_native_function, "resolve_native_function" },
74 { PATCHER_invokestatic_special, "invokestatic_special" },
75 { PATCHER_invokevirtual, "invokevirtual" },
76 { PATCHER_invokeinterface, "invokeinterface" },
77 { NULL, "-UNKNOWN PATCHER FUNCTION-" }
82 /* patcher_list_create *********************************************************
84 Creates an empty patcher list for the given codeinfo.
86 *******************************************************************************/
88 void patcher_list_create(codeinfo *code)
90 code->patchers = list_create(OFFSET(patchref_t, linkage));
94 /* patcher_list_reset **********************************************************
96 Resets the patcher list inside a codeinfo. This is usefull when
97 resetting a codeinfo for recompiling.
99 *******************************************************************************/
101 void patcher_list_reset(codeinfo *code)
105 /* free all elements of the list */
107 while((pr = list_first(code->patchers)) != NULL) {
108 list_remove(code->patchers, pr);
110 FREE(pr, patchref_t);
112 #if defined(ENABLE_STATISTICS)
114 size_patchref -= sizeof(patchref_t);
119 /* patcher_list_free ***********************************************************
121 Frees the patcher list and all its entries for the given codeinfo.
123 *******************************************************************************/
125 void patcher_list_free(codeinfo *code)
127 /* free all elements of the list */
129 patcher_list_reset(code);
131 /* free the list itself */
133 FREE(code->patchers, list_t);
137 /* patcher_list_find ***********************************************************
139 Find an entry inside the patcher list for the given codeinfo
140 by specifying the program counter of the patcher position.
142 NOTE: Caller should hold the patcher list lock or maintain
143 exclusive access otherwise.
145 *******************************************************************************/
147 static patchref_t *patcher_list_find(codeinfo *code, u1 *pc)
151 /* walk through all patcher references for the given codeinfo */
153 pr = list_first(code->patchers);
157 /*#define TRACE_PATCHER_FIND*/
158 #ifdef TRACE_PATCHER_FIND
159 log_println("patcher_list_find: %p == %p", pr->mpc, pc);
162 if (pr->mpc == (ptrint) pc)
165 pr = list_next(code->patchers, pr);
172 /* patcher_add_patch_ref *******************************************************
174 Appends a new patcher reference to the list of patching positions.
176 *******************************************************************************/
178 void patcher_add_patch_ref(jitdata *jd, functionptr patcher, void* ref, s4 disp)
187 patchmpc = cd->mcodeptr - cd->mcodebase;
190 if (patcher_list_find(code, (u1 *) (intptr_t) patchmpc) != NULL)
191 vm_abort("patcher_add_patch_ref: different patchers at same position.");
194 /* allocate patchref on heap (at least freed together with codeinfo) */
196 pr = NEW(patchref_t);
197 list_add_first(code->patchers, pr);
199 #if defined(ENABLE_STATISTICS)
201 size_patchref += sizeof(patchref_t);
204 /* set patcher information (mpc is resolved later) */
208 pr->patcher = patcher;
213 #if defined(ENABLE_JIT) && (defined(__I386__) || defined(__M68K__) || defined(__SPARC_64__) || defined(__X86_64__))
215 /* XXX We can remove that when we don't use UD2 anymore on i386
218 /* On some architectures the patcher stub call instruction might
219 be longer than the actual instruction generated. On this
220 architectures we store the last patcher call position and after
221 the basic block code generation is completed, we check the
222 range and maybe generate some nop's. */
223 /* The nops are generated in codegen_emit in each codegen */
225 cd->lastmcodeptr = cd->mcodeptr + PATCHER_CALL_SIZE;
231 * Resolve all patchers in the current JIT run.
233 * @param jd JIT data-structure
235 void patcher_resolve(jitdata* jd)
240 /* Get required compiler data. */
244 for (pr = list_first(code->patchers); pr != NULL; pr = list_next(code->patchers, pr)) {
245 pr->mpc += (intptr_t) code->entrypoint;
246 pr->datap = (intptr_t) (pr->disp + code->entrypoint);
252 * Check if the patcher is already patched. This is done by comparing
253 * the machine instruction.
255 * @param pr Patcher structure.
257 * @return true if patched, false otherwise.
259 bool patcher_is_patched(patchref_t* pr)
261 // Validate the instruction at the patching position is the same
262 // instruction as the patcher structure contains.
263 uint32_t mcode = *((uint32_t*) pr->mpc);
265 if (mcode != pr->mcode) {
277 bool patcher_is_patched_at(void* pc)
279 codeinfo* code = code_find_codeinfo_for_pc(pc);
281 // Get the patcher for the given PC.
282 patchref_t* pr = patcher_list_find(code, pc);
285 // The given PC is not a patcher position.
289 // Validate the instruction.
290 return patcher_is_patched(pr);
294 /* patcher_handler *************************************************************
296 Handles the request to patch JIT code at the given patching
297 position. This function is normally called by the signal
300 NOTE: The patcher list lock is used to maintain exclusive
301 access of the patched position (in fact of the whole code).
302 After patching has suceeded, the patcher reference should be
303 removed from the patcher list to avoid double patching.
305 *******************************************************************************/
308 /* XXX this indent is not thread safe! */
309 /* XXX if you want it thread safe, place patcher_depth in threadobject! */
310 static int patcher_depth = 0;
311 #define TRACE_PATCHER_INDENT for (i=0; i<patcher_depth; i++) printf("\t")
312 #endif /* !defined(NDEBUG) */
314 java_handle_t *patcher_handler(u1 *pc)
321 patcher_function_list_t *l;
325 /* define the patcher function */
327 bool (*patcher_function)(patchref_t *);
329 /* search the codeinfo for the given PC */
331 code = code_find_codeinfo_for_pc(pc);
334 /* enter a monitor on the patcher list */
336 LOCK_MONITOR_ENTER(code->patchers);
338 /* search the patcher information for the given PC */
340 pr = patcher_list_find(code, pc);
343 vm_abort("patcher_handler: Unable to find patcher reference.");
347 if (opt_DebugPatcher) {
348 log_println("patcher_handler: double-patching detected!");
351 LOCK_MONITOR_EXIT(code->patchers);
356 if (opt_DebugPatcher) {
357 for (l = patcher_function_list; l->patcher != NULL; l++)
358 if (l->patcher == pr->patcher)
361 TRACE_PATCHER_INDENT; printf("patching in "); method_print(code->m); printf(" at %p\n", (void *) pr->mpc);
362 TRACE_PATCHER_INDENT; printf("\tpatcher function = %s <%p>\n", l->name, (void *) (intptr_t) pr->patcher);
364 TRACE_PATCHER_INDENT;
365 printf("\tmachine code before = ");
367 # if defined(ENABLE_DISASSEMBLER)
368 disassinstr((void *) pr->mpc);
370 printf("%x at %p (disassembler disabled)\n", *((uint32_t*) pr->mpc), (void*) pr->mpc);
374 assert(patcher_depth > 0);
378 /* cast the passed function to a patcher function */
380 patcher_function = (bool (*)(patchref_t *)) (ptrint) pr->patcher;
382 /* call the proper patcher function */
384 result = (patcher_function)(pr);
387 if (opt_DebugPatcher) {
388 assert(patcher_depth > 0);
391 TRACE_PATCHER_INDENT;
392 printf("\tmachine code after = ");
394 # if defined(ENABLE_DISASSEMBLER)
395 disassinstr((void *) pr->mpc);
397 printf("%x at %p (disassembler disabled)\n", *((uint32_t*) pr->mpc), (void*) pr->mpc);
400 if (result == false) {
401 TRACE_PATCHER_INDENT; printf("\tPATCHER EXCEPTION!\n");
406 /* check for return value and exit accordingly */
408 if (result == false) {
409 e = exceptions_get_and_clear_exception();
411 LOCK_MONITOR_EXIT(code->patchers);
416 pr->done = true; /* XXX this is only preliminary to prevent double-patching */
418 LOCK_MONITOR_EXIT(code->patchers);
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)
496 /* get stuff from the patcher reference */
498 m = (methodinfo *) pr->ref;
499 datap = (uint8_t *) pr->datap;
501 /* resolve native function */
503 if (!(f = native_method_resolve(m)))
506 /* patch native function pointer */
508 *((intptr_t *) datap) = (intptr_t) f;
510 /* synchronize data cache */
512 md_dcacheflush(datap, SIZEOF_VOID_P);
514 /* patch back original code */
516 patcher_patch_code(pr);
523 * These are local overrides for various environment variables in Emacs.
524 * Please do not remove this and leave it at the end of the file, where
525 * Emacs will automagically detect them.
526 * ---------------------------------------------------------------------
529 * indent-tabs-mode: t
533 * vim:noexpandtab:sw=4:ts=4: