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Comparing BasiliskII/src/Unix/sigsegv.cpp (file contents):
Revision 1.11 by gbeauche, 2002-05-12T13:51:22Z vs.
Revision 1.30 by gbeauche, 2003-10-13T19:56:17Z

# Line 4 | Line 4
4   *  Derived from Bruno Haible's work on his SIGSEGV library for clisp
5   *  <http://clisp.sourceforge.net/>
6   *
7 + *  MacOS X support derived from the post by Timothy J. Wood to the
8 + *  omnigroup macosx-dev list:
9 + *    Mach Exception Handlers 101 (Was Re: ptrace, gdb)
10 + *    tjw@omnigroup.com Sun, 4 Jun 2000
11 + *    www.omnigroup.com/mailman/archive/macosx-dev/2000-June/002030.html
12 + *
13   *  Basilisk II (C) 1997-2002 Christian Bauer
14   *
15   *  This program is free software; you can redistribute it and/or modify
# Line 29 | Line 35
35   #include "config.h"
36   #endif
37  
38 + #include <list>
39   #include <signal.h>
40   #include "sigsegv.h"
41  
42 + #ifndef NO_STD_NAMESPACE
43 + using std::list;
44 + #endif
45 +
46   // Return value type of a signal handler (standard type if not defined)
47   #ifndef RETSIGTYPE
48   #define RETSIGTYPE void
# Line 40 | Line 51
51   // Type of the system signal handler
52   typedef RETSIGTYPE (*signal_handler)(int);
53  
43 // Is the fault to be ignored?
44 static bool sigsegv_ignore_fault = false;
45
54   // User's SIGSEGV handler
55 < static sigsegv_handler_t sigsegv_user_handler = 0;
55 > static sigsegv_fault_handler_t sigsegv_fault_handler = 0;
56  
57   // Function called to dump state if we can't handle the fault
58 < static sigsegv_handler_t sigsegv_dump_state = 0;
58 > static sigsegv_state_dumper_t sigsegv_state_dumper = 0;
59  
60   // Actual SIGSEGV handler installer
61   static bool sigsegv_do_install_handler(int sig);
62  
63  
64   /*
65 + *  Instruction decoding aids
66 + */
67 +
68 + // Transfer size
69 + enum transfer_size_t {
70 +        SIZE_UNKNOWN,
71 +        SIZE_BYTE,
72 +        SIZE_WORD,
73 +        SIZE_LONG
74 + };
75 +
76 + // Transfer type
77 + typedef sigsegv_transfer_type_t transfer_type_t;
78 +
79 + #if (defined(powerpc) || defined(__powerpc__) || defined(__ppc__))
80 + // Addressing mode
81 + enum addressing_mode_t {
82 +        MODE_UNKNOWN,
83 +        MODE_NORM,
84 +        MODE_U,
85 +        MODE_X,
86 +        MODE_UX
87 + };
88 +
89 + // Decoded instruction
90 + struct instruction_t {
91 +        transfer_type_t         transfer_type;
92 +        transfer_size_t         transfer_size;
93 +        addressing_mode_t       addr_mode;
94 +        unsigned int            addr;
95 +        char                            ra, rd;
96 + };
97 +
98 + static void powerpc_decode_instruction(instruction_t *instruction, unsigned int nip, unsigned int * gpr)
99 + {
100 +        // Get opcode and divide into fields
101 +        unsigned int opcode = *((unsigned int *)nip);
102 +        unsigned int primop = opcode >> 26;
103 +        unsigned int exop = (opcode >> 1) & 0x3ff;
104 +        unsigned int ra = (opcode >> 16) & 0x1f;
105 +        unsigned int rb = (opcode >> 11) & 0x1f;
106 +        unsigned int rd = (opcode >> 21) & 0x1f;
107 +        signed int imm = (signed short)(opcode & 0xffff);
108 +        
109 +        // Analyze opcode
110 +        transfer_type_t transfer_type = SIGSEGV_TRANSFER_UNKNOWN;
111 +        transfer_size_t transfer_size = SIZE_UNKNOWN;
112 +        addressing_mode_t addr_mode = MODE_UNKNOWN;
113 +        switch (primop) {
114 +        case 31:
115 +                switch (exop) {
116 +                case 23:        // lwzx
117 +                        transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_LONG; addr_mode = MODE_X; break;
118 +                case 55:        // lwzux
119 +                        transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_LONG; addr_mode = MODE_UX; break;
120 +                case 87:        // lbzx
121 +                        transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_BYTE; addr_mode = MODE_X; break;
122 +                case 119:       // lbzux
123 +                        transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_BYTE; addr_mode = MODE_UX; break;
124 +                case 151:       // stwx
125 +                        transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_LONG; addr_mode = MODE_X; break;
126 +                case 183:       // stwux
127 +                        transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_LONG; addr_mode = MODE_UX; break;
128 +                case 215:       // stbx
129 +                        transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_BYTE; addr_mode = MODE_X; break;
130 +                case 247:       // stbux
131 +                        transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_BYTE; addr_mode = MODE_UX; break;
132 +                case 279:       // lhzx
133 +                        transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_X; break;
134 +                case 311:       // lhzux
135 +                        transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_UX; break;
136 +                case 343:       // lhax
137 +                        transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_X; break;
138 +                case 375:       // lhaux
139 +                        transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_UX; break;
140 +                case 407:       // sthx
141 +                        transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_WORD; addr_mode = MODE_X; break;
142 +                case 439:       // sthux
143 +                        transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_WORD; addr_mode = MODE_UX; break;
144 +                }
145 +                break;
146 +        
147 +        case 32:        // lwz
148 +                transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_LONG; addr_mode = MODE_NORM; break;
149 +        case 33:        // lwzu
150 +                transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_LONG; addr_mode = MODE_U; break;
151 +        case 34:        // lbz
152 +                transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_BYTE; addr_mode = MODE_NORM; break;
153 +        case 35:        // lbzu
154 +                transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_BYTE; addr_mode = MODE_U; break;
155 +        case 36:        // stw
156 +                transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_LONG; addr_mode = MODE_NORM; break;
157 +        case 37:        // stwu
158 +                transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_LONG; addr_mode = MODE_U; break;
159 +        case 38:        // stb
160 +                transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_BYTE; addr_mode = MODE_NORM; break;
161 +        case 39:        // stbu
162 +                transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_BYTE; addr_mode = MODE_U; break;
163 +        case 40:        // lhz
164 +                transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_NORM; break;
165 +        case 41:        // lhzu
166 +                transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_U; break;
167 +        case 42:        // lha
168 +                transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_NORM; break;
169 +        case 43:        // lhau
170 +                transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_U; break;
171 +        case 44:        // sth
172 +                transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_WORD; addr_mode = MODE_NORM; break;
173 +        case 45:        // sthu
174 +                transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_WORD; addr_mode = MODE_U; break;
175 +        }
176 +        
177 +        // Calculate effective address
178 +        unsigned int addr = 0;
179 +        switch (addr_mode) {
180 +        case MODE_X:
181 +        case MODE_UX:
182 +                if (ra == 0)
183 +                        addr = gpr[rb];
184 +                else
185 +                        addr = gpr[ra] + gpr[rb];
186 +                break;
187 +        case MODE_NORM:
188 +        case MODE_U:
189 +                if (ra == 0)
190 +                        addr = (signed int)(signed short)imm;
191 +                else
192 +                        addr = gpr[ra] + (signed int)(signed short)imm;
193 +                break;
194 +        default:
195 +                break;
196 +        }
197 +        
198 +        // Commit decoded instruction
199 +        instruction->addr = addr;
200 +        instruction->addr_mode = addr_mode;
201 +        instruction->transfer_type = transfer_type;
202 +        instruction->transfer_size = transfer_size;
203 +        instruction->ra = ra;
204 +        instruction->rd = rd;
205 + }
206 + #endif
207 +
208 +
209 + /*
210   *  OS-dependant SIGSEGV signals support section
211   */
212  
213   #if HAVE_SIGINFO_T
214   // Generic extended signal handler
215 + #define SIGSEGV_FAULT_HANDLER                   sigsegv_fault_handler
216   #if defined(__NetBSD__) || defined(__FreeBSD__)
217   #define SIGSEGV_ALL_SIGNALS                             FAULT_HANDLER(SIGBUS)
218   #else
219   #define SIGSEGV_ALL_SIGNALS                             FAULT_HANDLER(SIGSEGV)
220   #endif
221   #define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, siginfo_t *sip, void *scp
222 + #define SIGSEGV_FAULT_HANDLER_ARGLIST_1 siginfo_t *sip, void *scp
223 + #define SIGSEGV_FAULT_HANDLER_ARGS              sip, scp
224   #define SIGSEGV_FAULT_ADDRESS                   sip->si_addr
225 + #if defined(__NetBSD__) || defined(__FreeBSD__)
226 + #if (defined(i386) || defined(__i386__))
227 + #define SIGSEGV_FAULT_INSTRUCTION               (((struct sigcontext *)scp)->sc_eip)
228 + #define SIGSEGV_REGISTER_FILE                   ((unsigned int *)&(((struct sigcontext *)scp)->sc_edi)) /* EDI is the first GPR (even below EIP) in sigcontext */
229 + #define SIGSEGV_SKIP_INSTRUCTION                ix86_skip_instruction
230 + #endif
231 + #endif
232   #if defined(__linux__)
233   #if (defined(i386) || defined(__i386__))
234   #include <sys/ucontext.h>
235 < #define SIGSEGV_FAULT_INSTRUCTION               (((ucontext_t *)scp)->uc_mcontext.gregs[14]) /* should use REG_EIP instead */
236 < #define SIGSEGV_REGISTER_FILE                   (unsigned long *)(((ucontext_t *)scp)->uc_mcontext.gregs)
235 > #define SIGSEGV_CONTEXT_REGS                    (((ucontext_t *)scp)->uc_mcontext.gregs)
236 > #define SIGSEGV_FAULT_INSTRUCTION               SIGSEGV_CONTEXT_REGS[14] /* should use REG_EIP instead */
237 > #define SIGSEGV_REGISTER_FILE                   (unsigned int *)SIGSEGV_CONTEXT_REGS
238   #define SIGSEGV_SKIP_INSTRUCTION                ix86_skip_instruction
239   #endif
240 + #if (defined(x86_64) || defined(__x86_64__))
241 + #include <sys/ucontext.h>
242 + #define SIGSEGV_CONTEXT_REGS                    (((ucontext_t *)scp)->uc_mcontext.gregs)
243 + #define SIGSEGV_FAULT_INSTRUCTION               SIGSEGV_CONTEXT_REGS[16] /* should use REG_RIP instead */
244 + #define SIGSEGV_REGISTER_FILE                   (unsigned long *)SIGSEGV_CONTEXT_REGS
245 + #endif
246   #if (defined(ia64) || defined(__ia64__))
247   #define SIGSEGV_FAULT_INSTRUCTION               (((struct sigcontext *)scp)->sc_ip & ~0x3ULL) /* slot number is in bits 0 and 1 */
248   #endif
249   #if (defined(powerpc) || defined(__powerpc__))
250   #include <sys/ucontext.h>
251 < #define SIGSEGV_FAULT_INSTRUCTION               (((ucontext_t *)scp)->uc_mcontext.regs->nip)
251 > #define SIGSEGV_CONTEXT_REGS                    (((ucontext_t *)scp)->uc_mcontext.regs)
252 > #define SIGSEGV_FAULT_INSTRUCTION               (SIGSEGV_CONTEXT_REGS->nip)
253 > #define SIGSEGV_REGISTER_FILE                   (unsigned int *)&SIGSEGV_CONTEXT_REGS->nip, (unsigned int *)(SIGSEGV_CONTEXT_REGS->gpr)
254 > #define SIGSEGV_SKIP_INSTRUCTION                powerpc_skip_instruction
255   #endif
256   #endif
257   #endif
258  
259   #if HAVE_SIGCONTEXT_SUBTERFUGE
260 + #define SIGSEGV_FAULT_HANDLER                   sigsegv_fault_handler
261   // Linux kernels prior to 2.4 ?
262   #if defined(__linux__)
263   #define SIGSEGV_ALL_SIGNALS                             FAULT_HANDLER(SIGSEGV)
264   #if (defined(i386) || defined(__i386__))
265   #include <asm/sigcontext.h>
266   #define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, struct sigcontext scs
267 < #define SIGSEGV_FAULT_ADDRESS                   scs.cr2
268 < #define SIGSEGV_FAULT_INSTRUCTION               scs.eip
269 < #define SIGSEGV_REGISTER_FILE                   (unsigned long *)(&scs)
267 > #define SIGSEGV_FAULT_HANDLER_ARGLIST_1 struct sigcontext *scp
268 > #define SIGSEGV_FAULT_HANDLER_ARGS              &scs
269 > #define SIGSEGV_FAULT_ADDRESS                   scp->cr2
270 > #define SIGSEGV_FAULT_INSTRUCTION               scp->eip
271 > #define SIGSEGV_REGISTER_FILE                   (unsigned int *)scp
272   #define SIGSEGV_SKIP_INSTRUCTION                ix86_skip_instruction
273   #endif
274   #if (defined(sparc) || defined(__sparc__))
275   #include <asm/sigcontext.h>
276   #define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, int code, struct sigcontext *scp, char *addr
277 + #define SIGSEGV_FAULT_HANDLER_ARGS              sig, code, scp, addr
278   #define SIGSEGV_FAULT_ADDRESS                   addr
279   #endif
280   #if (defined(powerpc) || defined(__powerpc__))
281   #include <asm/sigcontext.h>
282   #define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, struct sigcontext *scp
283 + #define SIGSEGV_FAULT_HANDLER_ARGS              sig, scp
284   #define SIGSEGV_FAULT_ADDRESS                   scp->regs->dar
285   #define SIGSEGV_FAULT_INSTRUCTION               scp->regs->nip
286 + #define SIGSEGV_REGISTER_FILE                   (unsigned int *)&scp->regs->nip, (unsigned int *)(scp->regs->gpr)
287 + #define SIGSEGV_SKIP_INSTRUCTION                powerpc_skip_instruction
288   #endif
289   #if (defined(alpha) || defined(__alpha__))
290   #include <asm/sigcontext.h>
291   #define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, int code, struct sigcontext *scp
292 + #define SIGSEGV_FAULT_HANDLER_ARGS              sig, code, scp
293   #define SIGSEGV_FAULT_ADDRESS                   get_fault_address(scp)
294   #define SIGSEGV_FAULT_INSTRUCTION               scp->sc_pc
295  
# Line 127 | Line 308 | static sigsegv_address_t get_fault_addre
308   #if (defined(sgi) || defined(__sgi)) && (defined(SYSTYPE_SVR4) || defined(__SYSTYPE_SVR4))
309   #include <ucontext.h>
310   #define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, int code, struct sigcontext *scp
311 + #define SIGSEGV_FAULT_HANDLER_ARGS              sig, code, scp
312   #define SIGSEGV_FAULT_ADDRESS                   scp->sc_badvaddr
313   #define SIGSEGV_ALL_SIGNALS                             FAULT_HANDLER(SIGSEGV)
314   #endif
# Line 134 | Line 316 | static sigsegv_address_t get_fault_addre
316   // HP-UX
317   #if (defined(hpux) || defined(__hpux__))
318   #define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, int code, struct sigcontext *scp
319 + #define SIGSEGV_FAULT_HANDLER_ARGS              sig, code, scp
320   #define SIGSEGV_FAULT_ADDRESS                   scp->sc_sl.sl_ss.ss_narrow.ss_cr21
321   #define SIGSEGV_ALL_SIGNALS                             FAULT_HANDLER(SIGSEGV) FAULT_HANDLER(SIGBUS)
322   #endif
# Line 142 | Line 325 | static sigsegv_address_t get_fault_addre
325   #if defined(__osf__)
326   #include <ucontext.h>
327   #define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, int code, struct sigcontext *scp
328 + #define SIGSEGV_FAULT_HANDLER_ARGS              sig, code, scp
329   #define SIGSEGV_FAULT_ADDRESS                   scp->sc_traparg_a0
330   #define SIGSEGV_ALL_SIGNALS                             FAULT_HANDLER(SIGSEGV)
331   #endif
# Line 149 | Line 333 | static sigsegv_address_t get_fault_addre
333   // AIX
334   #if defined(_AIX)
335   #define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, int code, struct sigcontext *scp
336 + #define SIGSEGV_FAULT_HANDLER_ARGS              sig, code, scp
337   #define SIGSEGV_FAULT_ADDRESS                   scp->sc_jmpbuf.jmp_context.o_vaddr
338   #define SIGSEGV_ALL_SIGNALS                             FAULT_HANDLER(SIGSEGV)
339   #endif
# Line 158 | Line 343 | static sigsegv_address_t get_fault_addre
343   #if (defined(m68k) || defined(__m68k__))
344   #include <m68k/frame.h>
345   #define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, int code, struct sigcontext *scp
346 < #define SIGSEGV_FAULT_ADDRESS                   ({                                                                                                                              \
347 <        struct sigstate {                                                                                                                                                                       \
163 <                int ss_flags;                                                                                                                                                                   \
164 <                struct frame ss_frame;                                                                                                                                                  \
165 <        };                                                                                                                                                                                                      \
166 <        struct sigstate *state = (struct sigstate *)scp->sc_ap;                                                                                         \
167 <        char *fault_addr;                                                                                                                                                                       \
168 <        switch (state->ss_frame.f_format) {                                                                                                                                     \
169 <        case 7:         /* 68040 access error */                                                                                                                                \
170 <                /* "code" is sometimes unreliable (i.e. contains NULL or a bogus address), reason unknown */    \
171 <                fault_addr = state->ss_frame.f_fmt7.f_fa;                                                                                                               \
172 <                break;                                                                                                                                                                                  \
173 <        default:                                                                                                                                                                                        \
174 <                fault_addr = (char *)code;                                                                                                                                              \
175 <                break;                                                                                                                                                                                  \
176 <        }                                                                                                                                                                                                       \
177 <        fault_addr;                                                                                                                                                                                     \
178 < })
346 > #define SIGSEGV_FAULT_HANDLER_ARGS              sig, code, scp
347 > #define SIGSEGV_FAULT_ADDRESS                   get_fault_address(scp)
348   #define SIGSEGV_ALL_SIGNALS                             FAULT_HANDLER(SIGSEGV)
349 +
350 + // Use decoding scheme from BasiliskII/m68k native
351 + static sigsegv_address_t get_fault_address(struct sigcontext *scp)
352 + {
353 +        struct sigstate {
354 +                int ss_flags;
355 +                struct frame ss_frame;
356 +        };
357 +        struct sigstate *state = (struct sigstate *)scp->sc_ap;
358 +        char *fault_addr;
359 +        switch (state->ss_frame.f_format) {
360 +        case 7:         /* 68040 access error */
361 +                /* "code" is sometimes unreliable (i.e. contains NULL or a bogus address), reason unknown */
362 +                fault_addr = state->ss_frame.f_fmt7.f_fa;
363 +                break;
364 +        default:
365 +                fault_addr = (char *)code;
366 +                break;
367 +        }
368 +        return (sigsegv_address_t)fault_addr;
369 + }
370   #else
371   #define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, int code, void *scp, char *addr
372 + #define SIGSEGV_FAULT_HANDLER_ARGS              sig, code, scp, addr
373   #define SIGSEGV_FAULT_ADDRESS                   addr
374   #define SIGSEGV_ALL_SIGNALS                             FAULT_HANDLER(SIGBUS)
375   #endif
376   #endif
377  
378 < // MacOS X
378 > // MacOS X, not sure which version this works in. Under 10.1
379 > // vm_protect does not appear to work from a signal handler. Under
380 > // 10.2 signal handlers get siginfo type arguments but the si_addr
381 > // field is the address of the faulting instruction and not the
382 > // address that caused the SIGBUS. Maybe this works in 10.0? In any
383 > // case with Mach exception handlers there is a way to do what this
384 > // was meant to do.
385 > #ifndef HAVE_MACH_EXCEPTIONS
386   #if defined(__APPLE__) && defined(__MACH__)
387   #if (defined(ppc) || defined(__ppc__))
388   #define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, int code, struct sigcontext *scp
389 + #define SIGSEGV_FAULT_HANDLER_ARGS              sig, code, scp
390   #define SIGSEGV_FAULT_ADDRESS                   get_fault_address(scp)
391   #define SIGSEGV_FAULT_INSTRUCTION               scp->sc_ir
392   #define SIGSEGV_ALL_SIGNALS                             FAULT_HANDLER(SIGBUS)
393 + #define SIGSEGV_REGISTER_FILE                   (unsigned int *)&scp->sc_ir, &((unsigned int *) scp->sc_regs)[2]
394 + #define SIGSEGV_SKIP_INSTRUCTION                powerpc_skip_instruction
395  
396 < // From Boehm's GC 6.0alpha8
196 < #define EXTRACT_OP1(iw)     (((iw) & 0xFC000000) >> 26)
197 < #define EXTRACT_OP2(iw)     (((iw) & 0x000007FE) >> 1)
198 < #define EXTRACT_REGA(iw)    (((iw) & 0x001F0000) >> 16)
199 < #define EXTRACT_REGB(iw)    (((iw) & 0x03E00000) >> 21)
200 < #define EXTRACT_REGC(iw)    (((iw) & 0x0000F800) >> 11)
201 < #define EXTRACT_DISP(iw)    ((short *) &(iw))[1]
202 <
396 > // Use decoding scheme from SheepShaver
397   static sigsegv_address_t get_fault_address(struct sigcontext *scp)
398   {
399 <        unsigned int   instr = *((unsigned int *) scp->sc_ir);
400 <        unsigned int * regs = &((unsigned int *) scp->sc_regs)[2];
401 <        int            disp = 0, tmp;
402 <        unsigned int   baseA = 0, baseB = 0;
403 <        unsigned int   addr, alignmask = 0xFFFFFFFF;
404 <
405 <        switch(EXTRACT_OP1(instr)) {
406 <        case 38:   /* stb */
407 <        case 39:   /* stbu */
408 <        case 54:   /* stfd */
409 <        case 55:   /* stfdu */
410 <        case 52:   /* stfs */
411 <        case 53:   /* stfsu */
412 <        case 44:   /* sth */
413 <        case 45:   /* sthu */
414 <        case 47:   /* stmw */
415 <        case 36:   /* stw */
416 <        case 37:   /* stwu */
417 <                tmp = EXTRACT_REGA(instr);
418 <                if(tmp > 0)
419 <                        baseA = regs[tmp];
420 <                disp = EXTRACT_DISP(instr);
421 <                break;
422 <        case 31:
423 <                switch(EXTRACT_OP2(instr)) {
424 <                case 86:    /* dcbf */
425 <                case 54:    /* dcbst */
426 <                case 1014:  /* dcbz */
427 <                case 247:   /* stbux */
428 <                case 215:   /* stbx */
429 <                case 759:   /* stfdux */
430 <                case 727:   /* stfdx */
431 <                case 983:   /* stfiwx */
432 <                case 695:   /* stfsux */
433 <                case 663:   /* stfsx */
434 <                case 918:   /* sthbrx */
435 <                case 439:   /* sthux */
436 <                case 407:   /* sthx */
437 <                case 661:   /* stswx */
438 <                case 662:   /* stwbrx */
439 <                case 150:   /* stwcx. */
440 <                case 183:   /* stwux */
441 <                case 151:   /* stwx */
442 <                case 135:   /* stvebx */
443 <                case 167:   /* stvehx */
444 <                case 199:   /* stvewx */
445 <                case 231:   /* stvx */
446 <                case 487:   /* stvxl */
447 <                        tmp = EXTRACT_REGA(instr);
448 <                        if(tmp > 0)
449 <                                baseA = regs[tmp];
450 <                        baseB = regs[EXTRACT_REGC(instr)];
451 <                        /* determine Altivec alignment mask */
452 <                        switch(EXTRACT_OP2(instr)) {
453 <                        case 167:   /* stvehx */
454 <                                alignmask = 0xFFFFFFFE;
455 <                                break;
456 <                        case 199:   /* stvewx */
457 <                                alignmask = 0xFFFFFFFC;
458 <                                break;
459 <                        case 231:   /* stvx */
460 <                                alignmask = 0xFFFFFFF0;
461 <                                break;
462 <                        case 487:  /* stvxl */
463 <                                alignmask = 0xFFFFFFF0;
464 <                                break;
465 <                        }
466 <                        break;
467 <                case 725:   /* stswi */
468 <                        tmp = EXTRACT_REGA(instr);
469 <                        if(tmp > 0)
470 <                                baseA = regs[tmp];
471 <                        break;
472 <                default:   /* ignore instruction */
473 <                        return 0;
474 <                        break;
399 >        unsigned int   nip = (unsigned int) scp->sc_ir;
400 >        unsigned int * gpr = &((unsigned int *) scp->sc_regs)[2];
401 >        instruction_t  instr;
402 >
403 >        powerpc_decode_instruction(&instr, nip, gpr);
404 >        return (sigsegv_address_t)instr.addr;
405 > }
406 > #endif
407 > #endif
408 > #endif
409 > #endif
410 >
411 > #if HAVE_MACH_EXCEPTIONS
412 >
413 > // This can easily be extended to other Mach systems, but really who
414 > // uses HURD (oops GNU/HURD), Darwin/x86, NextStep, Rhapsody, or CMU
415 > // Mach 2.5/3.0?
416 > #if defined(__APPLE__) && defined(__MACH__)
417 >
418 > #include <sys/types.h>
419 > #include <stdlib.h>
420 > #include <stdio.h>
421 > #include <pthread.h>
422 >
423 > /*
424 > * If you are familiar with MIG then you will understand the frustration
425 > * that was necessary to get these embedded into C++ code by hand.
426 > */
427 > extern "C" {
428 > #include <mach/mach.h>
429 > #include <mach/mach_error.h>
430 >
431 > extern boolean_t exc_server(mach_msg_header_t *, mach_msg_header_t *);
432 > extern kern_return_t catch_exception_raise(mach_port_t, mach_port_t,
433 >        mach_port_t, exception_type_t, exception_data_t, mach_msg_type_number_t);
434 > extern kern_return_t exception_raise(mach_port_t, mach_port_t, mach_port_t,
435 >        exception_type_t, exception_data_t, mach_msg_type_number_t);
436 > extern kern_return_t exception_raise_state(mach_port_t, exception_type_t,
437 >        exception_data_t, mach_msg_type_number_t, thread_state_flavor_t *,
438 >        thread_state_t, mach_msg_type_number_t, thread_state_t, mach_msg_type_number_t *);
439 > extern kern_return_t exception_raise_state_identity(mach_port_t, mach_port_t, mach_port_t,
440 >        exception_type_t, exception_data_t, mach_msg_type_number_t, thread_state_flavor_t *,
441 >        thread_state_t, mach_msg_type_number_t, thread_state_t, mach_msg_type_number_t *);
442 > }
443 >
444 > // Could make this dynamic by looking for a result of MIG_ARRAY_TOO_LARGE
445 > #define HANDLER_COUNT 64
446 >
447 > // structure to tuck away existing exception handlers
448 > typedef struct _ExceptionPorts {
449 >        mach_msg_type_number_t maskCount;
450 >        exception_mask_t masks[HANDLER_COUNT];
451 >        exception_handler_t handlers[HANDLER_COUNT];
452 >        exception_behavior_t behaviors[HANDLER_COUNT];
453 >        thread_state_flavor_t flavors[HANDLER_COUNT];
454 > } ExceptionPorts;
455 >
456 > // exception handler thread
457 > static pthread_t exc_thread;
458 >
459 > // place where old exception handler info is stored
460 > static ExceptionPorts ports;
461 >
462 > // our exception port
463 > static mach_port_t _exceptionPort = MACH_PORT_NULL;
464 >
465 > #define MACH_CHECK_ERROR(name,ret) \
466 > if (ret != KERN_SUCCESS) { \
467 >        mach_error(#name, ret); \
468 >        exit (1); \
469 > }
470 >
471 > #define SIGSEGV_FAULT_ADDRESS                   code[1]
472 > #define SIGSEGV_FAULT_INSTRUCTION               get_fault_instruction(thread, state)
473 > #define SIGSEGV_FAULT_HANDLER                   (code[0] == KERN_PROTECTION_FAILURE) && sigsegv_fault_handler
474 > #define SIGSEGV_FAULT_HANDLER_ARGLIST   mach_port_t thread, exception_data_t code, ppc_thread_state_t *state
475 > #define SIGSEGV_FAULT_HANDLER_ARGS              thread, code, &state
476 > #define SIGSEGV_SKIP_INSTRUCTION                powerpc_skip_instruction
477 > #define SIGSEGV_REGISTER_FILE                   &state->srr0, &state->r0
478 >
479 > // Given a suspended thread, stuff the current instruction and
480 > // registers into state.
481 > //
482 > // It would have been nice to have this be ppc/x86 independant which
483 > // could have been done easily with a thread_state_t instead of
484 > // ppc_thread_state_t, but because of the way this is called it is
485 > // easier to do it this way.
486 > #if (defined(ppc) || defined(__ppc__))
487 > static inline sigsegv_address_t get_fault_instruction(mach_port_t thread, ppc_thread_state_t *state)
488 > {
489 >        kern_return_t krc;
490 >        mach_msg_type_number_t count;
491 >
492 >        count = MACHINE_THREAD_STATE_COUNT;
493 >        krc = thread_get_state(thread, MACHINE_THREAD_STATE, (thread_state_t)state, &count);
494 >        MACH_CHECK_ERROR (thread_get_state, krc);
495 >
496 >        return (sigsegv_address_t)state->srr0;
497 > }
498 > #endif
499 >
500 > // Since there can only be one exception thread running at any time
501 > // this is not a problem.
502 > #define MSG_SIZE 512
503 > static char msgbuf[MSG_SIZE];
504 > static char replybuf[MSG_SIZE];
505 >
506 > /*
507 > * This is the entry point for the exception handler thread. The job
508 > * of this thread is to wait for exception messages on the exception
509 > * port that was setup beforehand and to pass them on to exc_server.
510 > * exc_server is a MIG generated function that is a part of Mach.
511 > * Its job is to decide what to do with the exception message. In our
512 > * case exc_server calls catch_exception_raise on our behalf. After
513 > * exc_server returns, it is our responsibility to send the reply.
514 > */
515 > static void *
516 > handleExceptions(void *priv)
517 > {
518 >        mach_msg_header_t *msg, *reply;
519 >        kern_return_t krc;
520 >
521 >        msg = (mach_msg_header_t *)msgbuf;
522 >        reply = (mach_msg_header_t *)replybuf;
523 >
524 >        for (;;) {
525 >                krc = mach_msg(msg, MACH_RCV_MSG, MSG_SIZE, MSG_SIZE,
526 >                                _exceptionPort, 0, MACH_PORT_NULL);
527 >                MACH_CHECK_ERROR(mach_msg, krc);
528 >
529 >                if (!exc_server(msg, reply)) {
530 >                        fprintf(stderr, "exc_server hated the message\n");
531 >                        exit(1);
532 >                }
533 >
534 >                krc = mach_msg(reply, MACH_SEND_MSG, reply->msgh_size, 0,
535 >                                 msg->msgh_local_port, 0, MACH_PORT_NULL);
536 >                if (krc != KERN_SUCCESS) {
537 >                        fprintf(stderr, "Error sending message to original reply port, krc = %d, %s",
538 >                                krc, mach_error_string(krc));
539 >                        exit(1);
540                  }
282                break;
283        default:   /* ignore instruction */
284                return 0;
285                break;
541          }
287        
288        addr = (baseA + baseB) + disp;
289        addr &= alignmask;
290        return (sigsegv_address_t)addr;
542   }
543   #endif
544   #endif
545 < #endif
545 >
546 >
547 > /*
548 > *  Instruction skipping
549 > */
550  
551   #ifdef HAVE_SIGSEGV_SKIP_INSTRUCTION
552   // Decode and skip X86 instruction
# Line 309 | Line 564 | enum {
564          X86_REG_EDI = 4
565   };
566   #endif
567 + #if defined(__NetBSD__) || defined(__FreeBSD__)
568 + enum {
569 +        X86_REG_EIP = 10,
570 +        X86_REG_EAX = 7,
571 +        X86_REG_ECX = 6,
572 +        X86_REG_EDX = 5,
573 +        X86_REG_EBX = 4,
574 +        X86_REG_ESP = 13,
575 +        X86_REG_EBP = 2,
576 +        X86_REG_ESI = 1,
577 +        X86_REG_EDI = 0
578 + };
579 + #endif
580   // FIXME: this is partly redundant with the instruction decoding phase
581   // to discover transfer type and register number
582   static inline int ix86_step_over_modrm(unsigned char * p)
# Line 343 | Line 611 | static inline int ix86_step_over_modrm(u
611          return offset;
612   }
613  
614 < static bool ix86_skip_instruction(sigsegv_address_t fault_instruction, unsigned long * regs)
614 > static bool ix86_skip_instruction(unsigned int * regs)
615   {
616 <        unsigned char * eip = (unsigned char *)fault_instruction;
616 >        unsigned char * eip = (unsigned char *)regs[X86_REG_EIP];
617  
618          if (eip == 0)
619                  return false;
620          
621 <        // Transfer type
622 <        enum {
355 <                TYPE_UNKNOWN,
356 <                TYPE_LOAD,
357 <                TYPE_STORE
358 <        } transfer_type = TYPE_UNKNOWN;
359 <        
360 <        // Transfer size
361 <        enum {
362 <                SIZE_BYTE,
363 <                SIZE_WORD,
364 <                SIZE_LONG
365 <        } transfer_size = SIZE_LONG;
621 >        transfer_type_t transfer_type = SIGSEGV_TRANSFER_UNKNOWN;
622 >        transfer_size_t transfer_size = SIZE_LONG;
623          
624          int reg = -1;
625          int len = 0;
# Line 376 | Line 633 | static bool ix86_skip_instruction(sigseg
633  
634          // Decode instruction
635          switch (eip[0]) {
636 +        case 0x0f:
637 +            switch (eip[1]) {
638 +            case 0xb6: // MOVZX r32, r/m8
639 +            case 0xb7: // MOVZX r32, r/m16
640 +                switch (eip[2] & 0xc0) {
641 +                case 0x80:
642 +                    reg = (eip[2] >> 3) & 7;
643 +                    transfer_type = SIGSEGV_TRANSFER_LOAD;
644 +                    break;
645 +                case 0x40:
646 +                    reg = (eip[2] >> 3) & 7;
647 +                    transfer_type = SIGSEGV_TRANSFER_LOAD;
648 +                    break;
649 +                case 0x00:
650 +                    reg = (eip[2] >> 3) & 7;
651 +                    transfer_type = SIGSEGV_TRANSFER_LOAD;
652 +                    break;
653 +                }
654 +                len += 3 + ix86_step_over_modrm(eip + 2);
655 +                break;
656 +            }
657 +          break;
658          case 0x8a: // MOV r8, r/m8
659                  transfer_size = SIZE_BYTE;
660          case 0x8b: // MOV r32, r/m32 (or 16-bit operation)
661                  switch (eip[1] & 0xc0) {
662                  case 0x80:
663                          reg = (eip[1] >> 3) & 7;
664 <                        transfer_type = TYPE_LOAD;
664 >                        transfer_type = SIGSEGV_TRANSFER_LOAD;
665                          break;
666                  case 0x40:
667                          reg = (eip[1] >> 3) & 7;
668 <                        transfer_type = TYPE_LOAD;
668 >                        transfer_type = SIGSEGV_TRANSFER_LOAD;
669                          break;
670                  case 0x00:
671                          reg = (eip[1] >> 3) & 7;
672 <                        transfer_type = TYPE_LOAD;
672 >                        transfer_type = SIGSEGV_TRANSFER_LOAD;
673                          break;
674                  }
675                  len += 2 + ix86_step_over_modrm(eip + 1);
# Line 401 | Line 680 | static bool ix86_skip_instruction(sigseg
680                  switch (eip[1] & 0xc0) {
681                  case 0x80:
682                          reg = (eip[1] >> 3) & 7;
683 <                        transfer_type = TYPE_STORE;
683 >                        transfer_type = SIGSEGV_TRANSFER_STORE;
684                          break;
685                  case 0x40:
686                          reg = (eip[1] >> 3) & 7;
687 <                        transfer_type = TYPE_STORE;
687 >                        transfer_type = SIGSEGV_TRANSFER_STORE;
688                          break;
689                  case 0x00:
690                          reg = (eip[1] >> 3) & 7;
691 <                        transfer_type = TYPE_STORE;
691 >                        transfer_type = SIGSEGV_TRANSFER_STORE;
692                          break;
693                  }
694                  len += 2 + ix86_step_over_modrm(eip + 1);
695                  break;
696          }
697  
698 <        if (transfer_type == TYPE_UNKNOWN) {
698 >        if (transfer_type == SIGSEGV_TRANSFER_UNKNOWN) {
699                  // Unknown machine code, let it crash. Then patch the decoder
700                  return false;
701          }
702  
703 <        if (transfer_type == TYPE_LOAD && reg != -1) {
703 >        if (transfer_type == SIGSEGV_TRANSFER_LOAD && reg != -1) {
704                  static const int x86_reg_map[8] = {
705                          X86_REG_EAX, X86_REG_ECX, X86_REG_EDX, X86_REG_EBX,
706                          X86_REG_ESP, X86_REG_EBP, X86_REG_ESI, X86_REG_EDI
# Line 447 | Line 726 | static bool ix86_skip_instruction(sigseg
726   #if DEBUG
727          printf("%08x: %s %s access", regs[X86_REG_EIP],
728                     transfer_size == SIZE_BYTE ? "byte" : transfer_size == SIZE_WORD ? "word" : "long",
729 <                   transfer_type == TYPE_LOAD ? "read" : "write");
729 >                   transfer_type == SIGSEGV_TRANSFER_LOAD ? "read" : "write");
730          
731          if (reg != -1) {
732                  static const char * x86_reg_str_map[8] = {
733                          "eax", "ecx", "edx", "ebx",
734                          "esp", "ebp", "esi", "edi"
735                  };
736 <                printf(" %s register %%%s", transfer_type == TYPE_LOAD ? "to" : "from", x86_reg_str_map[reg]);
736 >                printf(" %s register %%%s", transfer_type == SIGSEGV_TRANSFER_LOAD ? "to" : "from", x86_reg_str_map[reg]);
737          }
738          printf(", %d bytes instruction\n", len);
739   #endif
# Line 463 | Line 742 | static bool ix86_skip_instruction(sigseg
742          return true;
743   }
744   #endif
745 +
746 + // Decode and skip PPC instruction
747 + #if (defined(powerpc) || defined(__powerpc__) || defined(__ppc__))
748 + static bool powerpc_skip_instruction(unsigned int * nip_p, unsigned int * regs)
749 + {
750 +        instruction_t instr;
751 +        powerpc_decode_instruction(&instr, *nip_p, regs);
752 +        
753 +        if (instr.transfer_type == SIGSEGV_TRANSFER_UNKNOWN) {
754 +                // Unknown machine code, let it crash. Then patch the decoder
755 +                return false;
756 +        }
757 +
758 + #if DEBUG
759 +        printf("%08x: %s %s access", *nip_p,
760 +                   instr.transfer_size == SIZE_BYTE ? "byte" : instr.transfer_size == SIZE_WORD ? "word" : "long",
761 +                   instr.transfer_type == SIGSEGV_TRANSFER_LOAD ? "read" : "write");
762 +        
763 +        if (instr.addr_mode == MODE_U || instr.addr_mode == MODE_UX)
764 +                printf(" r%d (ra = %08x)\n", instr.ra, instr.addr);
765 +        if (instr.transfer_type == SIGSEGV_TRANSFER_LOAD)
766 +                printf(" r%d (rd = 0)\n", instr.rd);
767 + #endif
768 +        
769 +        if (instr.addr_mode == MODE_U || instr.addr_mode == MODE_UX)
770 +                regs[instr.ra] = instr.addr;
771 +        if (instr.transfer_type == SIGSEGV_TRANSFER_LOAD)
772 +                regs[instr.rd] = 0;
773 +        
774 +        *nip_p += 4;
775 +        return true;
776 + }
777 + #endif
778   #endif
779  
780   // Fallbacks
781   #ifndef SIGSEGV_FAULT_INSTRUCTION
782   #define SIGSEGV_FAULT_INSTRUCTION               SIGSEGV_INVALID_PC
783   #endif
784 + #ifndef SIGSEGV_FAULT_HANDLER_ARGLIST_1
785 + #define SIGSEGV_FAULT_HANDLER_ARGLIST_1 SIGSEGV_FAULT_HANDLER_ARGLIST
786 + #endif
787  
788   // SIGSEGV recovery supported ?
789   #if defined(SIGSEGV_ALL_SIGNALS) && defined(SIGSEGV_FAULT_HANDLER_ARGLIST) && defined(SIGSEGV_FAULT_ADDRESS)
# Line 480 | Line 795 | static bool ix86_skip_instruction(sigseg
795   *  SIGSEGV global handler
796   */
797  
798 < #ifdef HAVE_SIGSEGV_RECOVERY
799 < static void sigsegv_handler(SIGSEGV_FAULT_HANDLER_ARGLIST)
798 > #if defined(HAVE_SIGSEGV_RECOVERY) || defined(HAVE_MACH_EXCEPTIONS)
799 > // This function handles the badaccess to memory.
800 > // It is called from the signal handler or the exception handler.
801 > static bool handle_badaccess(SIGSEGV_FAULT_HANDLER_ARGLIST_1)
802   {
803          sigsegv_address_t fault_address = (sigsegv_address_t)SIGSEGV_FAULT_ADDRESS;
804          sigsegv_address_t fault_instruction = (sigsegv_address_t)SIGSEGV_FAULT_INSTRUCTION;
488        bool fault_recovered = false;
805          
806          // Call user's handler and reinstall the global handler, if required
807 <        if (sigsegv_user_handler(fault_address, fault_instruction)) {
808 < #if (defined(HAVE_SIGACTION) ? defined(SIGACTION_NEED_REINSTALL) : defined(SIGNAL_NEED_REINSTALL))
809 <                sigsegv_do_install_handler(sig);
807 >        switch (sigsegv_fault_handler(fault_address, fault_instruction)) {
808 >        case SIGSEGV_RETURN_SUCCESS:
809 >                return true;
810 >
811 > #if HAVE_SIGSEGV_SKIP_INSTRUCTION
812 >        case SIGSEGV_RETURN_SKIP_INSTRUCTION:
813 >                // Call the instruction skipper with the register file
814 >                // available
815 >                if (SIGSEGV_SKIP_INSTRUCTION(SIGSEGV_REGISTER_FILE)) {
816 > #ifdef HAVE_MACH_EXCEPTIONS
817 >                        // Unlike UNIX signals where the thread state
818 >                        // is modified off of the stack, in Mach we
819 >                        // need to actually call thread_set_state to
820 >                        // have the register values updated.
821 >                        kern_return_t krc;
822 >
823 >                        krc = thread_set_state(thread,
824 >                                                                   MACHINE_THREAD_STATE, (thread_state_t)state,
825 >                                                                   MACHINE_THREAD_STATE_COUNT);
826 >                        MACH_CHECK_ERROR (thread_get_state, krc);
827 > #endif
828 >                        return true;
829 >                }
830 >                break;
831   #endif
495                fault_recovered = true;
832          }
833 < #if HAVE_SIGSEGV_SKIP_INSTRUCTION
834 <        else if (sigsegv_ignore_fault) {
835 <                // Call the instruction skipper with the register file available
836 <                if (SIGSEGV_SKIP_INSTRUCTION(fault_instruction, SIGSEGV_REGISTER_FILE))
837 <                        fault_recovered = true;
833 >        
834 >        // We can't do anything with the fault_address, dump state?
835 >        if (sigsegv_state_dumper != 0)
836 >                sigsegv_state_dumper(fault_address, fault_instruction);
837 >
838 >        return false;
839 > }
840 > #endif
841 >
842 >
843 > /*
844 > * There are two mechanisms for handling a bad memory access,
845 > * Mach exceptions and UNIX signals. The implementation specific
846 > * code appears below. Its reponsibility is to call handle_badaccess
847 > * which is the routine that handles the fault in an implementation
848 > * agnostic manner. The implementation specific code below is then
849 > * reponsible for checking whether handle_badaccess was able
850 > * to handle the memory access error and perform any implementation
851 > * specific tasks necessary afterwards.
852 > */
853 >
854 > #ifdef HAVE_MACH_EXCEPTIONS
855 > /*
856 > * We need to forward all exceptions that we do not handle.
857 > * This is important, there are many exceptions that may be
858 > * handled by other exception handlers. For example debuggers
859 > * use exceptions and the exception hander is in another
860 > * process in such a case. (Timothy J. Wood states in his
861 > * message to the list that he based this code on that from
862 > * gdb for Darwin.)
863 > */
864 > static inline kern_return_t
865 > forward_exception(mach_port_t thread_port,
866 >                                  mach_port_t task_port,
867 >                                  exception_type_t exception_type,
868 >                                  exception_data_t exception_data,
869 >                                  mach_msg_type_number_t data_count,
870 >                                  ExceptionPorts *oldExceptionPorts)
871 > {
872 >        kern_return_t kret;
873 >        unsigned int portIndex;
874 >        mach_port_t port;
875 >        exception_behavior_t behavior;
876 >        thread_state_flavor_t flavor;
877 >        thread_state_t thread_state;
878 >        mach_msg_type_number_t thread_state_count;
879 >
880 >        for (portIndex = 0; portIndex < oldExceptionPorts->maskCount; portIndex++) {
881 >                if (oldExceptionPorts->masks[portIndex] & (1 << exception_type)) {
882 >                        // This handler wants the exception
883 >                        break;
884 >                }
885 >        }
886 >
887 >        if (portIndex >= oldExceptionPorts->maskCount) {
888 >                fprintf(stderr, "No handler for exception_type = %d. Not fowarding\n", exception_type);
889 >                return KERN_FAILURE;
890 >        }
891 >
892 >        port = oldExceptionPorts->handlers[portIndex];
893 >        behavior = oldExceptionPorts->behaviors[portIndex];
894 >        flavor = oldExceptionPorts->flavors[portIndex];
895 >
896 >        /*
897 >         fprintf(stderr, "forwarding exception, port = 0x%x, behaviour = %d, flavor = %d\n", port, behavior, flavor);
898 >         */
899 >
900 >        if (behavior != EXCEPTION_DEFAULT) {
901 >                thread_state_count = THREAD_STATE_MAX;
902 >                kret = thread_get_state (thread_port, flavor, thread_state,
903 >                                                                 &thread_state_count);
904 >                MACH_CHECK_ERROR (thread_get_state, kret);
905 >        }
906 >
907 >        switch (behavior) {
908 >        case EXCEPTION_DEFAULT:
909 >          // fprintf(stderr, "forwarding to exception_raise\n");
910 >          kret = exception_raise(port, thread_port, task_port, exception_type,
911 >                                                         exception_data, data_count);
912 >          MACH_CHECK_ERROR (exception_raise, kret);
913 >          break;
914 >        case EXCEPTION_STATE:
915 >          // fprintf(stderr, "forwarding to exception_raise_state\n");
916 >          kret = exception_raise_state(port, exception_type, exception_data,
917 >                                                                   data_count, &flavor,
918 >                                                                   thread_state, thread_state_count,
919 >                                                                   thread_state, &thread_state_count);
920 >          MACH_CHECK_ERROR (exception_raise_state, kret);
921 >          break;
922 >        case EXCEPTION_STATE_IDENTITY:
923 >          // fprintf(stderr, "forwarding to exception_raise_state_identity\n");
924 >          kret = exception_raise_state_identity(port, thread_port, task_port,
925 >                                                                                        exception_type, exception_data,
926 >                                                                                        data_count, &flavor,
927 >                                                                                        thread_state, thread_state_count,
928 >                                                                                        thread_state, &thread_state_count);
929 >          MACH_CHECK_ERROR (exception_raise_state_identity, kret);
930 >          break;
931 >        default:
932 >          fprintf(stderr, "forward_exception got unknown behavior\n");
933 >          break;
934 >        }
935 >
936 >        if (behavior != EXCEPTION_DEFAULT) {
937 >                kret = thread_set_state (thread_port, flavor, thread_state,
938 >                                                                 thread_state_count);
939 >                MACH_CHECK_ERROR (thread_set_state, kret);
940 >        }
941 >
942 >        return KERN_SUCCESS;
943 > }
944 >
945 > /*
946 > * This is the code that actually handles the exception.
947 > * It is called by exc_server. For Darwin 5 Apple changed
948 > * this a bit from how this family of functions worked in
949 > * Mach. If you are familiar with that it is a little
950 > * different. The main variation that concerns us here is
951 > * that code is an array of exception specific codes and
952 > * codeCount is a count of the number of codes in the code
953 > * array. In typical Mach all exceptions have a code
954 > * and sub-code. It happens to be the case that for a
955 > * EXC_BAD_ACCESS exception the first entry is the type of
956 > * bad access that occurred and the second entry is the
957 > * faulting address so these entries correspond exactly to
958 > * how the code and sub-code are used on Mach.
959 > *
960 > * This is a MIG interface. No code in Basilisk II should
961 > * call this directley. This has to have external C
962 > * linkage because that is what exc_server expects.
963 > */
964 > kern_return_t
965 > catch_exception_raise(mach_port_t exception_port,
966 >                                          mach_port_t thread,
967 >                                          mach_port_t task,
968 >                                          exception_type_t exception,
969 >                                          exception_data_t code,
970 >                                          mach_msg_type_number_t codeCount)
971 > {
972 >        ppc_thread_state_t state;
973 >        kern_return_t krc;
974 >
975 >        if ((exception == EXC_BAD_ACCESS)  && (codeCount >= 2)) {
976 >                if (handle_badaccess(SIGSEGV_FAULT_HANDLER_ARGS))
977 >                        return KERN_SUCCESS;
978          }
979 +
980 +        // In Mach we do not need to remove the exception handler.
981 +        // If we forward the exception, eventually some exception handler
982 +        // will take care of this exception.
983 +        krc = forward_exception(thread, task, exception, code, codeCount, &ports);
984 +
985 +        return krc;
986 + }
987 + #endif
988 +
989 + #ifdef HAVE_SIGSEGV_RECOVERY
990 + // Handle bad memory accesses with signal handler
991 + static void sigsegv_handler(SIGSEGV_FAULT_HANDLER_ARGLIST)
992 + {
993 +        // Call handler and reinstall the global handler, if required
994 +        if (handle_badaccess(SIGSEGV_FAULT_HANDLER_ARGS)) {
995 + #if (defined(HAVE_SIGACTION) ? defined(SIGACTION_NEED_REINSTALL) : defined(SIGNAL_NEED_REINSTALL))
996 +                sigsegv_do_install_handler(sig);
997   #endif
998 +                return;
999 +        }
1000  
1001 <        if (!fault_recovered) {
506 <                // FAIL: reinstall default handler for "safe" crash
1001 >        // Failure: reinstall default handler for "safe" crash
1002   #define FAULT_HANDLER(sig) signal(sig, SIG_DFL);
1003 <                SIGSEGV_ALL_SIGNALS
1003 >        SIGSEGV_ALL_SIGNALS
1004   #undef FAULT_HANDLER
510                
511                // We can't do anything with the fault_address, dump state?
512                if (sigsegv_dump_state != 0)
513                        sigsegv_dump_state(fault_address, fault_instruction);
514        }
1005   }
1006   #endif
1007  
# Line 525 | Line 1015 | static bool sigsegv_do_install_handler(i
1015   {
1016          // Setup SIGSEGV handler to process writes to frame buffer
1017   #ifdef HAVE_SIGACTION
1018 <        struct sigaction vosf_sa;
1019 <        sigemptyset(&vosf_sa.sa_mask);
1020 <        vosf_sa.sa_sigaction = sigsegv_handler;
1021 <        vosf_sa.sa_flags = SA_SIGINFO;
1022 <        return (sigaction(sig, &vosf_sa, 0) == 0);
1018 >        struct sigaction sigsegv_sa;
1019 >        sigemptyset(&sigsegv_sa.sa_mask);
1020 >        sigsegv_sa.sa_sigaction = sigsegv_handler;
1021 >        sigsegv_sa.sa_flags = SA_SIGINFO;
1022 >        return (sigaction(sig, &sigsegv_sa, 0) == 0);
1023   #else
1024          return (signal(sig, (signal_handler)sigsegv_handler) != SIG_ERR);
1025   #endif
# Line 541 | Line 1031 | static bool sigsegv_do_install_handler(i
1031   {
1032          // Setup SIGSEGV handler to process writes to frame buffer
1033   #ifdef HAVE_SIGACTION
1034 <        struct sigaction vosf_sa;
1035 <        sigemptyset(&vosf_sa.sa_mask);
1036 <        vosf_sa.sa_handler = (signal_handler)sigsegv_handler;
1034 >        struct sigaction sigsegv_sa;
1035 >        sigemptyset(&sigsegv_sa.sa_mask);
1036 >        sigsegv_sa.sa_handler = (signal_handler)sigsegv_handler;
1037 >        sigsegv_sa.sa_flags = 0;
1038   #if !EMULATED_68K && defined(__NetBSD__)
1039 <        sigaddset(&vosf_sa.sa_mask, SIGALRM);
1040 <        vosf_sa.sa_flags = SA_ONSTACK;
550 < #else
551 <        vosf_sa.sa_flags = 0;
1039 >        sigaddset(&sigsegv_sa.sa_mask, SIGALRM);
1040 >        sigsegv_sa.sa_flags |= SA_ONSTACK;
1041   #endif
1042 <        return (sigaction(sig, &vosf_sa, 0) == 0);
1042 >        return (sigaction(sig, &sigsegv_sa, 0) == 0);
1043   #else
1044          return (signal(sig, (signal_handler)sigsegv_handler) != SIG_ERR);
1045   #endif
1046   }
1047   #endif
1048  
1049 < bool sigsegv_install_handler(sigsegv_handler_t handler)
1049 > #if defined(HAVE_MACH_EXCEPTIONS)
1050 > static bool sigsegv_do_install_handler(sigsegv_fault_handler_t handler)
1051   {
1052 < #ifdef HAVE_SIGSEGV_RECOVERY
1053 <        sigsegv_user_handler = handler;
1052 >        /*
1053 >         * Except for the exception port functions, this should be
1054 >         * pretty much stock Mach. If later you choose to support
1055 >         * other Mach's besides Darwin, just check for __MACH__
1056 >         * here and __APPLE__ where the actual differences are.
1057 >         */
1058 > #if defined(__APPLE__) && defined(__MACH__)
1059 >        if (sigsegv_fault_handler != NULL) {
1060 >                sigsegv_fault_handler = handler;
1061 >                return true;
1062 >        }
1063 >
1064 >        kern_return_t krc;
1065 >
1066 >        // create the the exception port
1067 >        krc = mach_port_allocate(mach_task_self(),
1068 >                          MACH_PORT_RIGHT_RECEIVE, &_exceptionPort);
1069 >        if (krc != KERN_SUCCESS) {
1070 >                mach_error("mach_port_allocate", krc);
1071 >                return false;
1072 >        }
1073 >
1074 >        // add a port send right
1075 >        krc = mach_port_insert_right(mach_task_self(),
1076 >                              _exceptionPort, _exceptionPort,
1077 >                              MACH_MSG_TYPE_MAKE_SEND);
1078 >        if (krc != KERN_SUCCESS) {
1079 >                mach_error("mach_port_insert_right", krc);
1080 >                return false;
1081 >        }
1082 >
1083 >        // get the old exception ports
1084 >        ports.maskCount = sizeof (ports.masks) / sizeof (ports.masks[0]);
1085 >        krc = thread_get_exception_ports(mach_thread_self(), EXC_MASK_BAD_ACCESS, ports.masks,
1086 >                                &ports.maskCount, ports.handlers, ports.behaviors, ports.flavors);
1087 >        if (krc != KERN_SUCCESS) {
1088 >                mach_error("thread_get_exception_ports", krc);
1089 >                return false;
1090 >        }
1091 >
1092 >        // set the new exception port
1093 >        //
1094 >        // We could have used EXCEPTION_STATE_IDENTITY instead of
1095 >        // EXCEPTION_DEFAULT to get the thread state in the initial
1096 >        // message, but it turns out that in the common case this is not
1097 >        // neccessary. If we need it we can later ask for it from the
1098 >        // suspended thread.
1099 >        //
1100 >        // Even with THREAD_STATE_NONE, Darwin provides the program
1101 >        // counter in the thread state.  The comments in the header file
1102 >        // seem to imply that you can count on the GPR's on an exception
1103 >        // as well but just to be safe I use MACHINE_THREAD_STATE because
1104 >        // you have to ask for all of the GPR's anyway just to get the
1105 >        // program counter. In any case because of update effective
1106 >        // address from immediate and update address from effective
1107 >        // addresses of ra and rb modes (as good an name as any for these
1108 >        // addressing modes) used in PPC instructions, you will need the
1109 >        // GPR state anyway.
1110 >        krc = thread_set_exception_ports(mach_thread_self(), EXC_MASK_BAD_ACCESS, _exceptionPort,
1111 >                                EXCEPTION_DEFAULT, MACHINE_THREAD_STATE);
1112 >        if (krc != KERN_SUCCESS) {
1113 >                mach_error("thread_set_exception_ports", krc);
1114 >                return false;
1115 >        }
1116 >
1117 >        // create the exception handler thread
1118 >        if (pthread_create(&exc_thread, NULL, &handleExceptions, NULL) != 0) {
1119 >                (void)fprintf(stderr, "creation of exception thread failed\n");
1120 >                return false;
1121 >        }
1122 >
1123 >        // do not care about the exception thread any longer, let is run standalone
1124 >        (void)pthread_detach(exc_thread);
1125 >
1126 >        sigsegv_fault_handler = handler;
1127 >        return true;
1128 > #else
1129 >        return false;
1130 > #endif
1131 > }
1132 > #endif
1133 >
1134 > bool sigsegv_install_handler(sigsegv_fault_handler_t handler)
1135 > {
1136 > #if defined(HAVE_SIGSEGV_RECOVERY)
1137          bool success = true;
1138   #define FAULT_HANDLER(sig) success = success && sigsegv_do_install_handler(sig);
1139          SIGSEGV_ALL_SIGNALS
1140   #undef FAULT_HANDLER
1141 +        if (success)
1142 +            sigsegv_fault_handler = handler;
1143          return success;
1144 + #elif defined(HAVE_MACH_EXCEPTIONS)
1145 +        return sigsegv_do_install_handler(handler);
1146   #else
1147          // FAIL: no siginfo_t nor sigcontext subterfuge is available
1148          return false;
# Line 579 | Line 1156 | bool sigsegv_install_handler(sigsegv_han
1156  
1157   void sigsegv_deinstall_handler(void)
1158   {
1159 +  // We do nothing for Mach exceptions, the thread would need to be
1160 +  // suspended if not already so, and we might mess with other
1161 +  // exception handlers that came after we registered ours. There is
1162 +  // no need to remove the exception handler, in fact this function is
1163 +  // not called anywhere in Basilisk II.
1164   #ifdef HAVE_SIGSEGV_RECOVERY
1165 <        sigsegv_user_handler = 0;
1165 >        sigsegv_fault_handler = 0;
1166   #define FAULT_HANDLER(sig) signal(sig, SIG_DFL);
1167          SIGSEGV_ALL_SIGNALS
1168   #undef FAULT_HANDLER
# Line 589 | Line 1171 | void sigsegv_deinstall_handler(void)
1171  
1172  
1173   /*
592 *  SIGSEGV ignore state modifier
593 */
594
595 void sigsegv_set_ignore_state(bool ignore_fault)
596 {
597        sigsegv_ignore_fault = ignore_fault;
598 }
599
600
601 /*
1174   *  Set callback function when we cannot handle the fault
1175   */
1176  
1177 < void sigsegv_set_dump_state(sigsegv_handler_t handler)
1177 > void sigsegv_set_dump_state(sigsegv_state_dumper_t handler)
1178   {
1179 <        sigsegv_dump_state = handler;
1179 >        sigsegv_state_dumper = handler;
1180   }
1181  
1182  
# Line 623 | Line 1195 | static int page_size;
1195   static volatile char * page = 0;
1196   static volatile int handler_called = 0;
1197  
1198 < static bool sigsegv_test_handler(sigsegv_address_t fault_address, sigsegv_address_t instruction_address)
1198 > static sigsegv_return_t sigsegv_test_handler(sigsegv_address_t fault_address, sigsegv_address_t instruction_address)
1199   {
1200          handler_called++;
1201          if ((fault_address - 123) != page)
1202 <                exit(1);
1202 >                exit(10);
1203          if (vm_protect((char *)((unsigned long)fault_address & -page_size), page_size, VM_PAGE_READ | VM_PAGE_WRITE) != 0)
1204 <                exit(1);
1205 <        return true;
1204 >                exit(11);
1205 >        return SIGSEGV_RETURN_SUCCESS;
1206   }
1207  
1208   #ifdef HAVE_SIGSEGV_SKIP_INSTRUCTION
1209 < static bool sigsegv_insn_handler(sigsegv_address_t fault_address, sigsegv_address_t instruction_address)
1209 > #ifdef __GNUC__
1210 > // Code range where we expect the fault to come from
1211 > static void *b_region, *e_region;
1212 > #endif
1213 >
1214 > static sigsegv_return_t sigsegv_insn_handler(sigsegv_address_t fault_address, sigsegv_address_t instruction_address)
1215   {
1216 <        return false;
1216 >        if (((unsigned long)fault_address - (unsigned long)page) < page_size) {
1217 > #ifdef __GNUC__
1218 >                // Make sure reported fault instruction address falls into
1219 >                // expected code range
1220 >                if (instruction_address != SIGSEGV_INVALID_PC
1221 >                        && ((instruction_address <  (sigsegv_address_t)b_region) ||
1222 >                                (instruction_address >= (sigsegv_address_t)e_region)))
1223 >                        return SIGSEGV_RETURN_FAILURE;
1224 > #endif
1225 >                return SIGSEGV_RETURN_SKIP_INSTRUCTION;
1226 >        }
1227 >
1228 >        return SIGSEGV_RETURN_FAILURE;
1229   }
1230   #endif
1231  
# Line 647 | Line 1236 | int main(void)
1236  
1237          page_size = getpagesize();
1238          if ((page = (char *)vm_acquire(page_size)) == VM_MAP_FAILED)
1239 <                return 1;
1239 >                return 2;
1240          
1241          if (vm_protect((char *)page, page_size, VM_PAGE_READ) < 0)
1242 <                return 1;
1242 >                return 3;
1243          
1244          if (!sigsegv_install_handler(sigsegv_test_handler))
1245 <                return 1;
1245 >                return 4;
1246          
1247          page[123] = 45;
1248          page[123] = 45;
1249          
1250          if (handler_called != 1)
1251 <                return 1;
1251 >                return 5;
1252  
1253   #ifdef HAVE_SIGSEGV_SKIP_INSTRUCTION
1254          if (!sigsegv_install_handler(sigsegv_insn_handler))
1255 <                return 1;
1255 >                return 6;
1256          
1257 <        if (vm_protect((char *)page, page_size, VM_PAGE_WRITE) < 0)
1258 <                return 1;
1257 >        if (vm_protect((char *)page, page_size, VM_PAGE_READ | VM_PAGE_WRITE) < 0)
1258 >                return 7;
1259          
1260          for (int i = 0; i < page_size; i++)
1261                  page[i] = (i + 1) % page_size;
1262          
1263          if (vm_protect((char *)page, page_size, VM_PAGE_NOACCESS) < 0)
1264 <                return 1;
1264 >                return 8;
1265          
677        sigsegv_set_ignore_state(true);
678
1266   #define TEST_SKIP_INSTRUCTION(TYPE) do {                                \
1267                  const unsigned int TAG = 0x12345678;                    \
1268                  TYPE data = *((TYPE *)(page + sizeof(TYPE)));   \
1269                  volatile unsigned int effect = data + TAG;              \
1270                  if (effect != TAG)                                                              \
1271 <                        return 1;                                                                       \
1271 >                        return 9;                                                                       \
1272          } while (0)
1273          
1274 + #ifdef __GNUC__
1275 +        b_region = &&L_b_region;
1276 +        e_region = &&L_e_region;
1277 + #endif
1278 + L_b_region:
1279          TEST_SKIP_INSTRUCTION(unsigned char);
1280          TEST_SKIP_INSTRUCTION(unsigned short);
1281          TEST_SKIP_INSTRUCTION(unsigned int);
1282 + L_e_region:
1283   #endif
1284  
1285          vm_exit();

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