1 /* src/vm/jit/patcher-common.cpp - architecture independent code patching stuff
3 Copyright (C) 1996-2011
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/breakpoint.hpp"
47 #include "vm/exceptions.hpp"
48 #include "vm/hook.hpp"
49 #include "vm/initialize.hpp"
50 #include "vm/options.h"
52 #include "vm/resolve.hpp"
54 #include "vm/jit/code.hpp"
55 #include "vm/jit/disass.h"
56 #include "vm/jit/jit.hpp"
57 #include "vm/jit/patcher-common.hpp"
60 /* patcher_function_list *******************************************************
62 This is a list which maps patcher function pointers to the according
63 names of the patcher functions. It is only usefull for debugging
66 *******************************************************************************/
69 typedef struct patcher_function_list_t {
72 } patcher_function_list_t;
74 static patcher_function_list_t patcher_function_list[] = {
75 { PATCHER_initialize_class, "initialize_class" },
76 #ifdef ENABLE_VERIFIER
77 { PATCHER_resolve_class, "resolve_class" },
78 #endif /* ENABLE_VERIFIER */
79 { PATCHER_resolve_native_function, "resolve_native_function" },
80 { PATCHER_invokestatic_special, "invokestatic_special" },
81 { PATCHER_invokevirtual, "invokevirtual" },
82 { PATCHER_invokeinterface, "invokeinterface" },
83 { PATCHER_breakpoint, "breakpoint" },
84 { NULL, "-UNKNOWN PATCHER FUNCTION-" }
89 /* patcher_list_create *********************************************************
91 Creates an empty patcher list for the given codeinfo.
93 *******************************************************************************/
95 void patcher_list_create(codeinfo *code)
97 code->patchers = new LockedList<patchref_t>();
101 /* patcher_list_reset **********************************************************
103 Resets the patcher list inside a codeinfo. This is usefull when
104 resetting a codeinfo for recompiling.
106 *******************************************************************************/
108 void patcher_list_reset(codeinfo *code)
110 #if defined(ENABLE_STATISTICS)
112 size_patchref -= sizeof(patchref_t) * code->patchers->size();
115 // Free all elements of the list.
116 code->patchers->clear();
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.
128 patcher_list_reset(code);
130 // Free the list itself.
131 delete code->patchers;
136 * Find an entry inside the patcher list for the given codeinfo by
137 * specifying the program counter of the patcher position.
139 * NOTE: Caller should hold the patcher list lock or maintain
140 * exclusive access otherwise.
142 * @param pc Program counter to find.
144 * @return Pointer to patcher.
147 struct foo : public std::binary_function<patchref_t, void*, bool> {
148 bool operator() (const patchref_t& pr, const void* pc) const
150 return (pr.mpc == (uintptr_t) pc);
154 static patchref_t* patcher_list_find(codeinfo* code, void* pc)
156 // Search for a patcher with the given PC.
157 List<patchref_t>::iterator it = std::find_if(code->patchers->begin(), code->patchers->end(), std::bind2nd(foo(), pc));
159 if (it == code->patchers->end())
167 * Show the content of the whole patcher reference list for
168 * debugging purposes.
170 * @param code The codeinfo containing the patcher list.
173 void patcher_list_show(codeinfo *code)
175 for (List<patchref_t>::iterator it = code->patchers->begin(); it != code->patchers->end(); it++) {
176 patchref_t& pr = *it;
178 // Lookup name in patcher function list.
179 patcher_function_list_t* l;
180 for (l = patcher_function_list; l->patcher != NULL; l++)
181 if (l->patcher == pr.patcher)
184 // Display information about patcher.
185 printf("\tpatcher pc:"PRINTF_FORMAT_INTPTR_T, pr.mpc);
186 printf(" datap:"PRINTF_FORMAT_INTPTR_T, pr.datap);
187 printf(" ref:"PRINTF_FORMAT_INTPTR_T, (intptr_t) pr.ref);
188 #if PATCHER_CALL_SIZE == 4
189 printf(" mcode:%08x", (uint32_t) pr.mcode);
190 #elif PATCHER_CALL_SIZE == 2
191 printf(" mcode:%04x", (uint16_t) pr.mcode);
193 # error Unknown PATCHER_CALL_SIZE
195 printf(" type:%s\n", l->name);
197 // Display machine code of patched position.
198 #if 0 && defined(ENABLE_DISASSEMBLER)
199 printf("\t\tcurrent -> ");
200 disassinstr((uint8_t*) pr.mpc);
201 printf("\t\tapplied -> ");
202 disassinstr((uint8_t*) &(pr.mcode));
209 /* patcher_add_patch_ref *******************************************************
211 Appends a new patcher reference to the list of patching positions.
213 Returns a pointer to the newly created patchref_t.
215 *******************************************************************************/
217 patchref_t *patcher_add_patch_ref(jitdata *jd, functionptr patcher, void* ref, s4 disp)
219 codegendata *cd = jd->cd;
220 codeinfo *code = jd->code;
222 #if defined(ALIGN_PATCHER_TRAP)
223 emit_patcher_alignment(cd);
226 int32_t patchmpc = cd->mcodeptr - cd->mcodebase;
229 if (patcher_list_find(code, (void*) (intptr_t) patchmpc) != NULL)
230 os::abort("patcher_add_patch_ref: different patchers at same position.");
233 #if defined(USES_PATCHABLE_MEMORY_BARRIER)
237 // Set patcher information (mpc is resolved later).
245 pr.patcher = patcher;
250 // Store patcher in the list (NOTE: structure is copied).
251 code->patchers->push_back(pr);
253 #if defined(ENABLE_STATISTICS)
255 size_patchref += sizeof(patchref_t);
258 #if defined(ENABLE_JIT) && (defined(__I386__) || defined(__M68K__) || defined(__SPARC_64__) || defined(__X86_64__))
260 /* XXX We can remove that when we don't use UD2 anymore on i386
263 /* On some architectures the patcher stub call instruction might
264 be longer than the actual instruction generated. On this
265 architectures we store the last patcher call position and after
266 the basic block code generation is completed, we check the
267 range and maybe generate some nop's. */
268 /* The nops are generated in codegen_emit in each codegen */
270 cd->lastmcodeptr = cd->mcodeptr + PATCHER_CALL_SIZE;
273 return &code->patchers->back();
278 * Resolve all patchers in the current JIT run.
280 * @param jd JIT data-structure
282 void patcher_resolve(jitdata* jd)
284 // Get required compiler data.
285 codeinfo* code = jd->code;
287 for (List<patchref_t>::iterator it = code->patchers->begin(); it != code->patchers->end(); it++) {
288 patchref_t& pr = *it;
290 pr.mpc += (intptr_t) code->entrypoint;
291 pr.datap = (intptr_t) (pr.disp + code->entrypoint);
297 * Check if the patcher is already patched. This is done by comparing
298 * the machine instruction.
300 * @param pr Patcher structure.
302 * @return true if patched, false otherwise.
304 bool patcher_is_patched(patchref_t* pr)
306 // Validate the instruction at the patching position is the same
307 // instruction as the patcher structure contains.
308 uint32_t mcode = *((uint32_t*) pr->mpc);
310 #if PATCHER_CALL_SIZE == 4
311 if (mcode != pr->mcode) {
312 #elif PATCHER_CALL_SIZE == 2
313 if ((uint16_t) mcode != (uint16_t) pr->mcode) {
315 #error Unknown PATCHER_CALL_SIZE
328 bool patcher_is_patched_at(void* pc)
330 codeinfo* code = code_find_codeinfo_for_pc(pc);
332 // Get the patcher for the given PC.
333 patchref_t* pr = patcher_list_find(code, pc);
336 // The given PC is not a patcher position.
340 // Validate the instruction.
341 return patcher_is_patched(pr);
345 /* patcher_handler *************************************************************
347 Handles the request to patch JIT code at the given patching
348 position. This function is normally called by the signal
351 NOTE: The patcher list lock is used to maintain exclusive
352 access of the patched position (in fact of the whole code).
353 After patching has suceeded, the patcher reference should be
354 removed from the patcher list to avoid double patching.
356 *******************************************************************************/
359 /* XXX this indent is not thread safe! */
360 /* XXX if you want it thread safe, place patcher_depth in threadobject! */
361 static int patcher_depth = 0;
362 #define TRACE_PATCHER_INDENT for (i=0; i<patcher_depth; i++) printf("\t")
363 #endif /* !defined(NDEBUG) */
365 bool patcher_handler(u1 *pc)
371 patcher_function_list_t *l;
375 /* define the patcher function */
377 bool (*patcher_function)(patchref_t *);
379 /* search the codeinfo for the given PC */
381 code = code_find_codeinfo_for_pc(pc);
384 // Enter a mutex on the patcher list.
385 code->patchers->lock();
387 /* search the patcher information for the given PC */
389 pr = patcher_list_find(code, pc);
392 os::abort("patcher_handler: Unable to find patcher reference.");
396 if (opt_DebugPatcher) {
397 log_println("patcher_handler: double-patching detected!");
400 code->patchers->unlock();
405 if (opt_DebugPatcher) {
406 for (l = patcher_function_list; l->patcher != NULL; l++)
407 if (l->patcher == pr->patcher)
410 TRACE_PATCHER_INDENT; printf("patching in "); method_print(code->m); printf(" at %p\n", (void *) pr->mpc);
411 TRACE_PATCHER_INDENT; printf("\tpatcher function = %s <%p>\n", l->name, (void *) (intptr_t) pr->patcher);
413 TRACE_PATCHER_INDENT;
414 printf("\tmachine code before = ");
416 # if defined(ENABLE_DISASSEMBLER)
417 disassinstr((u1*) (void*) pr->mpc);
419 printf("%x at %p (disassembler disabled)\n", *((uint32_t*) pr->mpc), (void*) pr->mpc);
423 assert(patcher_depth > 0);
427 /* cast the passed function to a patcher function */
429 patcher_function = (bool (*)(patchref_t *)) (ptrint) pr->patcher;
431 /* call the proper patcher function */
433 result = (patcher_function)(pr);
436 if (opt_DebugPatcher) {
437 assert(patcher_depth > 0);
440 TRACE_PATCHER_INDENT;
441 printf("\tmachine code after = ");
443 # if defined(ENABLE_DISASSEMBLER)
444 disassinstr((u1*) (void*) pr->mpc);
446 printf("%x at %p (disassembler disabled)\n", *((uint32_t*) pr->mpc), (void*) pr->mpc);
449 if (result == false) {
450 TRACE_PATCHER_INDENT; printf("\tPATCHER EXCEPTION!\n");
455 // Check return value and mangle the pending exception.
457 resolve_handle_pending_exception(true);
459 // XXX This is only preliminary to prevent double-patching.
463 code->patchers->unlock();
469 /* patcher_initialize_class ****************************************************
471 Initalizes a given classinfo pointer.
472 This function does not patch any data.
474 *******************************************************************************/
476 bool patcher_initialize_class(patchref_t *pr)
480 /* get stuff from the patcher reference */
482 c = (classinfo *) pr->ref;
484 /* check if the class is initialized */
486 if (!(c->state & CLASS_INITIALIZED))
487 if (!initialize_class(c))
490 /* patch back original code */
492 patcher_patch_code(pr);
498 /* patcher_resolve_class *******************************************************
500 Resolves a given unresolved class reference.
501 This function does not patch any data.
503 *******************************************************************************/
505 #ifdef ENABLE_VERIFIER
506 bool patcher_resolve_class(patchref_t *pr)
508 unresolved_class *uc;
510 /* get stuff from the patcher reference */
512 uc = (unresolved_class *) pr->ref;
514 /* resolve the class and check subtype constraints */
516 if (!resolve_class_eager_no_access_check(uc))
519 /* patch back original code */
521 patcher_patch_code(pr);
525 #endif /* ENABLE_VERIFIER */
528 /* patcher_resolve_native_function *********************************************
530 Resolves the native function for a given methodinfo.
531 This function patches one data segment word.
533 *******************************************************************************/
535 bool patcher_resolve_native_function(patchref_t *pr)
540 /* get stuff from the patcher reference */
542 m = (methodinfo *) pr->ref;
543 datap = (uint8_t *) pr->datap;
545 /* resolve native function */
547 NativeMethods& nm = VM::get_current()->get_nativemethods();
548 void* f = nm.resolve_method(m);
553 /* patch native function pointer */
555 *((intptr_t*) datap) = (intptr_t) f;
557 /* synchronize data cache */
559 md_dcacheflush(datap, SIZEOF_VOID_P);
561 /* patch back original code */
563 patcher_patch_code(pr);
570 * Deals with breakpoint instructions (ICMD_BREAKPOINT) compiled
571 * into a JIT method. This patcher might never patch back the
572 * original machine code because breakpoints are kept active.
574 bool patcher_breakpoint(patchref_t *pr)
576 // Get stuff from the patcher reference.
577 Breakpoint* breakp = (Breakpoint*) pr->ref;
579 // Hook point when a breakpoint was triggered.
580 Hook::breakpoint(breakp);
582 // In case the breakpoint wants to be kept active, we simply
583 // fail to "patch" at this point.
584 if (!breakp->is_oneshot)
587 // Patch back original code.
588 patcher_patch_code(pr);
595 * These are local overrides for various environment variables in Emacs.
596 * Please do not remove this and leave it at the end of the file, where
597 * Emacs will automagically detect them.
598 * ---------------------------------------------------------------------
601 * indent-tabs-mode: t
605 * vim:noexpandtab:sw=4:ts=4: