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root/cebix/BasiliskII/src/Unix/sigsegv.cpp
Revision: 1.37
Committed: 2003-12-20T07:43:56Z (20 years, 10 months ago) by gbeauche
Branch: MAIN
Changes since 1.36: +8 -2 lines
Log Message:
Fix subterfuge mode on IRIX/mips. Get PC in both modes for Irix too

File Contents

# User Rev Content
1 gbeauche 1.1 /*
2     * sigsegv.cpp - SIGSEGV signals support
3     *
4     * Derived from Bruno Haible's work on his SIGSEGV library for clisp
5     * <http://clisp.sourceforge.net/>
6     *
7 gbeauche 1.27 * 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 cebix 1.7 * Basilisk II (C) 1997-2002 Christian Bauer
14 gbeauche 1.1 *
15     * This program is free software; you can redistribute it and/or modify
16     * it under the terms of the GNU General Public License as published by
17     * the Free Software Foundation; either version 2 of the License, or
18     * (at your option) any later version.
19     *
20     * This program is distributed in the hope that it will be useful,
21     * but WITHOUT ANY WARRANTY; without even the implied warranty of
22     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
23     * GNU General Public License for more details.
24     *
25     * You should have received a copy of the GNU General Public License
26     * along with this program; if not, write to the Free Software
27     * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
28     */
29    
30     #ifdef HAVE_UNISTD_H
31     #include <unistd.h>
32     #endif
33    
34     #ifdef HAVE_CONFIG_H
35     #include "config.h"
36     #endif
37    
38 gbeauche 1.22 #include <list>
39 gbeauche 1.1 #include <signal.h>
40     #include "sigsegv.h"
41    
42 gbeauche 1.22 #ifndef NO_STD_NAMESPACE
43     using std::list;
44     #endif
45    
46 gbeauche 1.1 // Return value type of a signal handler (standard type if not defined)
47     #ifndef RETSIGTYPE
48     #define RETSIGTYPE void
49     #endif
50    
51     // Type of the system signal handler
52     typedef RETSIGTYPE (*signal_handler)(int);
53    
54     // User's SIGSEGV handler
55 gbeauche 1.12 static sigsegv_fault_handler_t sigsegv_fault_handler = 0;
56 gbeauche 1.1
57 gbeauche 1.10 // Function called to dump state if we can't handle the fault
58 gbeauche 1.12 static sigsegv_state_dumper_t sigsegv_state_dumper = 0;
59 gbeauche 1.10
60 gbeauche 1.1 // Actual SIGSEGV handler installer
61     static bool sigsegv_do_install_handler(int sig);
62    
63    
64     /*
65 gbeauche 1.14 * Instruction decoding aids
66     */
67    
68     // Transfer size
69     enum transfer_size_t {
70     SIZE_UNKNOWN,
71     SIZE_BYTE,
72 gbeauche 1.34 SIZE_WORD, // 2 bytes
73     SIZE_LONG, // 4 bytes
74     SIZE_QUAD, // 8 bytes
75 gbeauche 1.14 };
76    
77 gbeauche 1.23 // Transfer type
78     typedef sigsegv_transfer_type_t transfer_type_t;
79    
80 gbeauche 1.14 #if (defined(powerpc) || defined(__powerpc__) || defined(__ppc__))
81     // Addressing mode
82     enum addressing_mode_t {
83     MODE_UNKNOWN,
84     MODE_NORM,
85     MODE_U,
86     MODE_X,
87     MODE_UX
88     };
89    
90     // Decoded instruction
91     struct instruction_t {
92     transfer_type_t transfer_type;
93     transfer_size_t transfer_size;
94     addressing_mode_t addr_mode;
95     unsigned int addr;
96     char ra, rd;
97     };
98    
99     static void powerpc_decode_instruction(instruction_t *instruction, unsigned int nip, unsigned int * gpr)
100     {
101     // Get opcode and divide into fields
102     unsigned int opcode = *((unsigned int *)nip);
103     unsigned int primop = opcode >> 26;
104     unsigned int exop = (opcode >> 1) & 0x3ff;
105     unsigned int ra = (opcode >> 16) & 0x1f;
106     unsigned int rb = (opcode >> 11) & 0x1f;
107     unsigned int rd = (opcode >> 21) & 0x1f;
108     signed int imm = (signed short)(opcode & 0xffff);
109    
110     // Analyze opcode
111 gbeauche 1.22 transfer_type_t transfer_type = SIGSEGV_TRANSFER_UNKNOWN;
112 gbeauche 1.14 transfer_size_t transfer_size = SIZE_UNKNOWN;
113     addressing_mode_t addr_mode = MODE_UNKNOWN;
114     switch (primop) {
115     case 31:
116     switch (exop) {
117     case 23: // lwzx
118 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_LONG; addr_mode = MODE_X; break;
119 gbeauche 1.14 case 55: // lwzux
120 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_LONG; addr_mode = MODE_UX; break;
121 gbeauche 1.14 case 87: // lbzx
122 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_BYTE; addr_mode = MODE_X; break;
123 gbeauche 1.14 case 119: // lbzux
124 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_BYTE; addr_mode = MODE_UX; break;
125 gbeauche 1.14 case 151: // stwx
126 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_LONG; addr_mode = MODE_X; break;
127 gbeauche 1.14 case 183: // stwux
128 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_LONG; addr_mode = MODE_UX; break;
129 gbeauche 1.14 case 215: // stbx
130 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_BYTE; addr_mode = MODE_X; break;
131 gbeauche 1.14 case 247: // stbux
132 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_BYTE; addr_mode = MODE_UX; break;
133 gbeauche 1.14 case 279: // lhzx
134 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_X; break;
135 gbeauche 1.14 case 311: // lhzux
136 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_UX; break;
137 gbeauche 1.14 case 343: // lhax
138 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_X; break;
139 gbeauche 1.14 case 375: // lhaux
140 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_UX; break;
141 gbeauche 1.14 case 407: // sthx
142 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_WORD; addr_mode = MODE_X; break;
143 gbeauche 1.14 case 439: // sthux
144 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_WORD; addr_mode = MODE_UX; break;
145 gbeauche 1.14 }
146     break;
147    
148     case 32: // lwz
149 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_LONG; addr_mode = MODE_NORM; break;
150 gbeauche 1.14 case 33: // lwzu
151 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_LONG; addr_mode = MODE_U; break;
152 gbeauche 1.14 case 34: // lbz
153 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_BYTE; addr_mode = MODE_NORM; break;
154 gbeauche 1.14 case 35: // lbzu
155 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_BYTE; addr_mode = MODE_U; break;
156 gbeauche 1.14 case 36: // stw
157 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_LONG; addr_mode = MODE_NORM; break;
158 gbeauche 1.14 case 37: // stwu
159 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_LONG; addr_mode = MODE_U; break;
160 gbeauche 1.14 case 38: // stb
161 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_BYTE; addr_mode = MODE_NORM; break;
162 gbeauche 1.14 case 39: // stbu
163 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_BYTE; addr_mode = MODE_U; break;
164 gbeauche 1.14 case 40: // lhz
165 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_NORM; break;
166 gbeauche 1.14 case 41: // lhzu
167 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_U; break;
168 gbeauche 1.14 case 42: // lha
169 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_NORM; break;
170 gbeauche 1.14 case 43: // lhau
171 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_U; break;
172 gbeauche 1.14 case 44: // sth
173 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_WORD; addr_mode = MODE_NORM; break;
174 gbeauche 1.14 case 45: // sthu
175 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_WORD; addr_mode = MODE_U; break;
176 gbeauche 1.14 }
177    
178     // Calculate effective address
179     unsigned int addr = 0;
180     switch (addr_mode) {
181     case MODE_X:
182     case MODE_UX:
183     if (ra == 0)
184     addr = gpr[rb];
185     else
186     addr = gpr[ra] + gpr[rb];
187     break;
188     case MODE_NORM:
189     case MODE_U:
190     if (ra == 0)
191     addr = (signed int)(signed short)imm;
192     else
193     addr = gpr[ra] + (signed int)(signed short)imm;
194     break;
195     default:
196     break;
197     }
198    
199     // Commit decoded instruction
200     instruction->addr = addr;
201     instruction->addr_mode = addr_mode;
202     instruction->transfer_type = transfer_type;
203     instruction->transfer_size = transfer_size;
204     instruction->ra = ra;
205     instruction->rd = rd;
206     }
207     #endif
208    
209    
210     /*
211 gbeauche 1.1 * OS-dependant SIGSEGV signals support section
212     */
213    
214     #if HAVE_SIGINFO_T
215     // Generic extended signal handler
216 cebix 1.8 #if defined(__NetBSD__) || defined(__FreeBSD__)
217     #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGBUS)
218     #else
219 gbeauche 1.1 #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
220 cebix 1.8 #endif
221 gbeauche 1.5 #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, siginfo_t *sip, void *scp
222 gbeauche 1.30 #define SIGSEGV_FAULT_HANDLER_ARGLIST_1 siginfo_t *sip, void *scp
223     #define SIGSEGV_FAULT_HANDLER_ARGS sip, scp
224 gbeauche 1.1 #define SIGSEGV_FAULT_ADDRESS sip->si_addr
225 gbeauche 1.37 #if (defined(sgi) || defined(__sgi))
226     #include <ucontext.h>
227     #define SIGSEGV_CONTEXT_REGS (((ucontext_t *)scp)->uc_mcontext.gregs)
228     #define SIGSEGV_FAULT_INSTRUCTION (unsigned long)SIGSEGV_CONTEXT_REGS[CTX_EPC]
229     #endif
230 gbeauche 1.32 #if defined(__sun__)
231     #if (defined(sparc) || defined(__sparc__))
232     #include <sys/ucontext.h>
233     #define SIGSEGV_CONTEXT_REGS (((ucontext_t *)scp)->uc_mcontext.gregs)
234     #define SIGSEGV_FAULT_INSTRUCTION SIGSEGV_CONTEXT_REGS[REG_PC]
235     #endif
236     #endif
237 gbeauche 1.33 #if defined(__FreeBSD__)
238 gbeauche 1.17 #if (defined(i386) || defined(__i386__))
239     #define SIGSEGV_FAULT_INSTRUCTION (((struct sigcontext *)scp)->sc_eip)
240 gbeauche 1.34 #define SIGSEGV_REGISTER_FILE ((unsigned long *)&(((struct sigcontext *)scp)->sc_edi)) /* EDI is the first GPR (even below EIP) in sigcontext */
241 gbeauche 1.17 #define SIGSEGV_SKIP_INSTRUCTION ix86_skip_instruction
242 gbeauche 1.19 #endif
243 gbeauche 1.17 #endif
244 gbeauche 1.5 #if defined(__linux__)
245 gbeauche 1.6 #if (defined(i386) || defined(__i386__))
246     #include <sys/ucontext.h>
247 gbeauche 1.14 #define SIGSEGV_CONTEXT_REGS (((ucontext_t *)scp)->uc_mcontext.gregs)
248     #define SIGSEGV_FAULT_INSTRUCTION SIGSEGV_CONTEXT_REGS[14] /* should use REG_EIP instead */
249 gbeauche 1.34 #define SIGSEGV_REGISTER_FILE (unsigned long *)SIGSEGV_CONTEXT_REGS
250 gbeauche 1.10 #define SIGSEGV_SKIP_INSTRUCTION ix86_skip_instruction
251 gbeauche 1.6 #endif
252 gbeauche 1.20 #if (defined(x86_64) || defined(__x86_64__))
253     #include <sys/ucontext.h>
254     #define SIGSEGV_CONTEXT_REGS (((ucontext_t *)scp)->uc_mcontext.gregs)
255     #define SIGSEGV_FAULT_INSTRUCTION SIGSEGV_CONTEXT_REGS[16] /* should use REG_RIP instead */
256     #define SIGSEGV_REGISTER_FILE (unsigned long *)SIGSEGV_CONTEXT_REGS
257 gbeauche 1.34 #define SIGSEGV_SKIP_INSTRUCTION ix86_skip_instruction
258 gbeauche 1.20 #endif
259 gbeauche 1.5 #if (defined(ia64) || defined(__ia64__))
260     #define SIGSEGV_FAULT_INSTRUCTION (((struct sigcontext *)scp)->sc_ip & ~0x3ULL) /* slot number is in bits 0 and 1 */
261     #endif
262 gbeauche 1.9 #if (defined(powerpc) || defined(__powerpc__))
263     #include <sys/ucontext.h>
264 gbeauche 1.14 #define SIGSEGV_CONTEXT_REGS (((ucontext_t *)scp)->uc_mcontext.regs)
265     #define SIGSEGV_FAULT_INSTRUCTION (SIGSEGV_CONTEXT_REGS->nip)
266     #define SIGSEGV_REGISTER_FILE (unsigned int *)&SIGSEGV_CONTEXT_REGS->nip, (unsigned int *)(SIGSEGV_CONTEXT_REGS->gpr)
267 gbeauche 1.13 #define SIGSEGV_SKIP_INSTRUCTION powerpc_skip_instruction
268 gbeauche 1.9 #endif
269 gbeauche 1.5 #endif
270 gbeauche 1.1 #endif
271    
272     #if HAVE_SIGCONTEXT_SUBTERFUGE
273     // Linux kernels prior to 2.4 ?
274     #if defined(__linux__)
275     #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
276     #if (defined(i386) || defined(__i386__))
277     #include <asm/sigcontext.h>
278     #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, struct sigcontext scs
279 gbeauche 1.30 #define SIGSEGV_FAULT_HANDLER_ARGLIST_1 struct sigcontext *scp
280     #define SIGSEGV_FAULT_HANDLER_ARGS &scs
281     #define SIGSEGV_FAULT_ADDRESS scp->cr2
282     #define SIGSEGV_FAULT_INSTRUCTION scp->eip
283 gbeauche 1.34 #define SIGSEGV_REGISTER_FILE (unsigned long *)scp
284 gbeauche 1.10 #define SIGSEGV_SKIP_INSTRUCTION ix86_skip_instruction
285 gbeauche 1.1 #endif
286     #if (defined(sparc) || defined(__sparc__))
287     #include <asm/sigcontext.h>
288 gbeauche 1.5 #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp, char *addr
289 gbeauche 1.30 #define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp, addr
290 gbeauche 1.1 #define SIGSEGV_FAULT_ADDRESS addr
291     #endif
292     #if (defined(powerpc) || defined(__powerpc__))
293     #include <asm/sigcontext.h>
294 gbeauche 1.4 #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, struct sigcontext *scp
295 gbeauche 1.30 #define SIGSEGV_FAULT_HANDLER_ARGS sig, scp
296 gbeauche 1.1 #define SIGSEGV_FAULT_ADDRESS scp->regs->dar
297     #define SIGSEGV_FAULT_INSTRUCTION scp->regs->nip
298 gbeauche 1.14 #define SIGSEGV_REGISTER_FILE (unsigned int *)&scp->regs->nip, (unsigned int *)(scp->regs->gpr)
299 gbeauche 1.13 #define SIGSEGV_SKIP_INSTRUCTION powerpc_skip_instruction
300 gbeauche 1.1 #endif
301 gbeauche 1.4 #if (defined(alpha) || defined(__alpha__))
302     #include <asm/sigcontext.h>
303     #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
304 gbeauche 1.30 #define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp
305 gbeauche 1.4 #define SIGSEGV_FAULT_ADDRESS get_fault_address(scp)
306     #define SIGSEGV_FAULT_INSTRUCTION scp->sc_pc
307     #endif
308 gbeauche 1.1 #endif
309    
310     // Irix 5 or 6 on MIPS
311 gbeauche 1.37 #if (defined(sgi) || defined(__sgi)) && (defined(SYSTYPE_SVR4) || defined(_SYSTYPE_SVR4))
312 gbeauche 1.11 #include <ucontext.h>
313 gbeauche 1.1 #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
314 gbeauche 1.30 #define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp
315 gbeauche 1.37 #define SIGSEGV_FAULT_ADDRESS (unsigned long)scp->sc_badvaddr
316     #define SIGSEGV_FAULT_INSTRUCTION (unsigned long)scp->sc_pc
317 gbeauche 1.1 #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
318     #endif
319    
320 gbeauche 1.11 // HP-UX
321     #if (defined(hpux) || defined(__hpux__))
322     #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
323 gbeauche 1.30 #define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp
324 gbeauche 1.11 #define SIGSEGV_FAULT_ADDRESS scp->sc_sl.sl_ss.ss_narrow.ss_cr21
325     #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV) FAULT_HANDLER(SIGBUS)
326     #endif
327    
328 gbeauche 1.1 // OSF/1 on Alpha
329     #if defined(__osf__)
330 gbeauche 1.11 #include <ucontext.h>
331 gbeauche 1.1 #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
332 gbeauche 1.30 #define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp
333 gbeauche 1.1 #define SIGSEGV_FAULT_ADDRESS scp->sc_traparg_a0
334     #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
335     #endif
336    
337     // AIX
338     #if defined(_AIX)
339     #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
340 gbeauche 1.30 #define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp
341 gbeauche 1.1 #define SIGSEGV_FAULT_ADDRESS scp->sc_jmpbuf.jmp_context.o_vaddr
342     #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
343     #endif
344    
345 gbeauche 1.33 // NetBSD
346     #if defined(__NetBSD__)
347 gbeauche 1.1 #if (defined(m68k) || defined(__m68k__))
348     #include <m68k/frame.h>
349     #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
350 gbeauche 1.30 #define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp
351 gbeauche 1.14 #define SIGSEGV_FAULT_ADDRESS get_fault_address(scp)
352 gbeauche 1.1 #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
353 gbeauche 1.14
354     // Use decoding scheme from BasiliskII/m68k native
355     static sigsegv_address_t get_fault_address(struct sigcontext *scp)
356     {
357     struct sigstate {
358     int ss_flags;
359     struct frame ss_frame;
360     };
361     struct sigstate *state = (struct sigstate *)scp->sc_ap;
362     char *fault_addr;
363     switch (state->ss_frame.f_format) {
364     case 7: /* 68040 access error */
365     /* "code" is sometimes unreliable (i.e. contains NULL or a bogus address), reason unknown */
366     fault_addr = state->ss_frame.f_fmt7.f_fa;
367     break;
368     default:
369     fault_addr = (char *)code;
370     break;
371     }
372     return (sigsegv_address_t)fault_addr;
373     }
374 gbeauche 1.33 #endif
375     #if (defined(alpha) || defined(__alpha__))
376     #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
377     #define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp
378     #define SIGSEGV_FAULT_ADDRESS get_fault_address(scp)
379     #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGBUS)
380     #endif
381     #if (defined(i386) || defined(__i386__))
382     #error "FIXME: need to decode instruction and compute EA"
383     #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
384     #define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp
385     #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
386     #endif
387     #endif
388     #if defined(__FreeBSD__)
389     #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGBUS)
390     #if (defined(i386) || defined(__i386__))
391     #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp, char *addr
392 gbeauche 1.30 #define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp, addr
393 gbeauche 1.1 #define SIGSEGV_FAULT_ADDRESS addr
394 gbeauche 1.33 #define SIGSEGV_FAULT_INSTRUCTION scp->sc_eip
395 gbeauche 1.34 #define SIGSEGV_REGISTER_FILE ((unsigned long *)&scp->sc_edi)
396 gbeauche 1.33 #define SIGSEGV_SKIP_INSTRUCTION ix86_skip_instruction
397 gbeauche 1.1 #endif
398     #endif
399 gbeauche 1.33
400     // Extract fault address out of a sigcontext
401     #if (defined(alpha) || defined(__alpha__))
402     // From Boehm's GC 6.0alpha8
403     static sigsegv_address_t get_fault_address(struct sigcontext *scp)
404     {
405     unsigned int instruction = *((unsigned int *)(scp->sc_pc));
406     unsigned long fault_address = scp->sc_regs[(instruction >> 16) & 0x1f];
407     fault_address += (signed long)(signed short)(instruction & 0xffff);
408     return (sigsegv_address_t)fault_address;
409     }
410     #endif
411    
412 gbeauche 1.4
413 gbeauche 1.27 // MacOS X, not sure which version this works in. Under 10.1
414     // vm_protect does not appear to work from a signal handler. Under
415     // 10.2 signal handlers get siginfo type arguments but the si_addr
416     // field is the address of the faulting instruction and not the
417     // address that caused the SIGBUS. Maybe this works in 10.0? In any
418     // case with Mach exception handlers there is a way to do what this
419     // was meant to do.
420     #ifndef HAVE_MACH_EXCEPTIONS
421 gbeauche 1.4 #if defined(__APPLE__) && defined(__MACH__)
422     #if (defined(ppc) || defined(__ppc__))
423     #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
424 gbeauche 1.27 #define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp
425 gbeauche 1.4 #define SIGSEGV_FAULT_ADDRESS get_fault_address(scp)
426     #define SIGSEGV_FAULT_INSTRUCTION scp->sc_ir
427     #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGBUS)
428 gbeauche 1.14 #define SIGSEGV_REGISTER_FILE (unsigned int *)&scp->sc_ir, &((unsigned int *) scp->sc_regs)[2]
429     #define SIGSEGV_SKIP_INSTRUCTION powerpc_skip_instruction
430 gbeauche 1.4
431 gbeauche 1.14 // Use decoding scheme from SheepShaver
432 gbeauche 1.4 static sigsegv_address_t get_fault_address(struct sigcontext *scp)
433     {
434 gbeauche 1.14 unsigned int nip = (unsigned int) scp->sc_ir;
435     unsigned int * gpr = &((unsigned int *) scp->sc_regs)[2];
436     instruction_t instr;
437    
438     powerpc_decode_instruction(&instr, nip, gpr);
439     return (sigsegv_address_t)instr.addr;
440 gbeauche 1.4 }
441     #endif
442     #endif
443 gbeauche 1.1 #endif
444 gbeauche 1.27 #endif
445    
446     #if HAVE_MACH_EXCEPTIONS
447    
448     // This can easily be extended to other Mach systems, but really who
449     // uses HURD (oops GNU/HURD), Darwin/x86, NextStep, Rhapsody, or CMU
450     // Mach 2.5/3.0?
451     #if defined(__APPLE__) && defined(__MACH__)
452    
453     #include <sys/types.h>
454     #include <stdlib.h>
455     #include <stdio.h>
456     #include <pthread.h>
457    
458     /*
459     * If you are familiar with MIG then you will understand the frustration
460     * that was necessary to get these embedded into C++ code by hand.
461     */
462     extern "C" {
463     #include <mach/mach.h>
464     #include <mach/mach_error.h>
465    
466     extern boolean_t exc_server(mach_msg_header_t *, mach_msg_header_t *);
467     extern kern_return_t catch_exception_raise(mach_port_t, mach_port_t,
468     mach_port_t, exception_type_t, exception_data_t, mach_msg_type_number_t);
469     extern kern_return_t exception_raise(mach_port_t, mach_port_t, mach_port_t,
470     exception_type_t, exception_data_t, mach_msg_type_number_t);
471     extern kern_return_t exception_raise_state(mach_port_t, exception_type_t,
472     exception_data_t, mach_msg_type_number_t, thread_state_flavor_t *,
473     thread_state_t, mach_msg_type_number_t, thread_state_t, mach_msg_type_number_t *);
474     extern kern_return_t exception_raise_state_identity(mach_port_t, mach_port_t, mach_port_t,
475     exception_type_t, exception_data_t, mach_msg_type_number_t, thread_state_flavor_t *,
476     thread_state_t, mach_msg_type_number_t, thread_state_t, mach_msg_type_number_t *);
477     }
478    
479     // Could make this dynamic by looking for a result of MIG_ARRAY_TOO_LARGE
480     #define HANDLER_COUNT 64
481    
482     // structure to tuck away existing exception handlers
483     typedef struct _ExceptionPorts {
484     mach_msg_type_number_t maskCount;
485     exception_mask_t masks[HANDLER_COUNT];
486     exception_handler_t handlers[HANDLER_COUNT];
487     exception_behavior_t behaviors[HANDLER_COUNT];
488     thread_state_flavor_t flavors[HANDLER_COUNT];
489     } ExceptionPorts;
490    
491     // exception handler thread
492     static pthread_t exc_thread;
493    
494     // place where old exception handler info is stored
495     static ExceptionPorts ports;
496    
497     // our exception port
498     static mach_port_t _exceptionPort = MACH_PORT_NULL;
499    
500     #define MACH_CHECK_ERROR(name,ret) \
501     if (ret != KERN_SUCCESS) { \
502     mach_error(#name, ret); \
503     exit (1); \
504     }
505    
506     #define SIGSEGV_FAULT_ADDRESS code[1]
507     #define SIGSEGV_FAULT_INSTRUCTION get_fault_instruction(thread, state)
508 gbeauche 1.31 #define SIGSEGV_FAULT_HANDLER_INVOKE(ADDR, IP) ((code[0] == KERN_PROTECTION_FAILURE) ? sigsegv_fault_handler(ADDR, IP) : SIGSEGV_RETURN_FAILURE)
509 gbeauche 1.27 #define SIGSEGV_FAULT_HANDLER_ARGLIST mach_port_t thread, exception_data_t code, ppc_thread_state_t *state
510     #define SIGSEGV_FAULT_HANDLER_ARGS thread, code, &state
511     #define SIGSEGV_SKIP_INSTRUCTION powerpc_skip_instruction
512     #define SIGSEGV_REGISTER_FILE &state->srr0, &state->r0
513    
514     // Given a suspended thread, stuff the current instruction and
515     // registers into state.
516     //
517     // It would have been nice to have this be ppc/x86 independant which
518     // could have been done easily with a thread_state_t instead of
519     // ppc_thread_state_t, but because of the way this is called it is
520     // easier to do it this way.
521     #if (defined(ppc) || defined(__ppc__))
522     static inline sigsegv_address_t get_fault_instruction(mach_port_t thread, ppc_thread_state_t *state)
523     {
524     kern_return_t krc;
525     mach_msg_type_number_t count;
526    
527     count = MACHINE_THREAD_STATE_COUNT;
528     krc = thread_get_state(thread, MACHINE_THREAD_STATE, (thread_state_t)state, &count);
529     MACH_CHECK_ERROR (thread_get_state, krc);
530    
531     return (sigsegv_address_t)state->srr0;
532     }
533     #endif
534    
535     // Since there can only be one exception thread running at any time
536     // this is not a problem.
537     #define MSG_SIZE 512
538     static char msgbuf[MSG_SIZE];
539     static char replybuf[MSG_SIZE];
540    
541     /*
542     * This is the entry point for the exception handler thread. The job
543     * of this thread is to wait for exception messages on the exception
544     * port that was setup beforehand and to pass them on to exc_server.
545     * exc_server is a MIG generated function that is a part of Mach.
546     * Its job is to decide what to do with the exception message. In our
547     * case exc_server calls catch_exception_raise on our behalf. After
548     * exc_server returns, it is our responsibility to send the reply.
549     */
550     static void *
551     handleExceptions(void *priv)
552     {
553     mach_msg_header_t *msg, *reply;
554     kern_return_t krc;
555    
556     msg = (mach_msg_header_t *)msgbuf;
557     reply = (mach_msg_header_t *)replybuf;
558    
559     for (;;) {
560     krc = mach_msg(msg, MACH_RCV_MSG, MSG_SIZE, MSG_SIZE,
561     _exceptionPort, 0, MACH_PORT_NULL);
562     MACH_CHECK_ERROR(mach_msg, krc);
563    
564     if (!exc_server(msg, reply)) {
565     fprintf(stderr, "exc_server hated the message\n");
566     exit(1);
567     }
568    
569     krc = mach_msg(reply, MACH_SEND_MSG, reply->msgh_size, 0,
570     msg->msgh_local_port, 0, MACH_PORT_NULL);
571     if (krc != KERN_SUCCESS) {
572     fprintf(stderr, "Error sending message to original reply port, krc = %d, %s",
573     krc, mach_error_string(krc));
574     exit(1);
575     }
576     }
577     }
578     #endif
579     #endif
580 gbeauche 1.1
581 gbeauche 1.14
582     /*
583     * Instruction skipping
584     */
585    
586 gbeauche 1.10 #ifdef HAVE_SIGSEGV_SKIP_INSTRUCTION
587     // Decode and skip X86 instruction
588 gbeauche 1.34 #if (defined(i386) || defined(__i386__)) || defined(__x86_64__)
589 gbeauche 1.10 #if defined(__linux__)
590     enum {
591 gbeauche 1.34 #if (defined(i386) || defined(__i386__))
592 gbeauche 1.10 X86_REG_EIP = 14,
593     X86_REG_EAX = 11,
594     X86_REG_ECX = 10,
595     X86_REG_EDX = 9,
596     X86_REG_EBX = 8,
597     X86_REG_ESP = 7,
598     X86_REG_EBP = 6,
599     X86_REG_ESI = 5,
600     X86_REG_EDI = 4
601 gbeauche 1.34 #endif
602     #if defined(__x86_64__)
603     X86_REG_R8 = 0,
604     X86_REG_R9 = 1,
605     X86_REG_R10 = 2,
606     X86_REG_R11 = 3,
607     X86_REG_R12 = 4,
608     X86_REG_R13 = 5,
609     X86_REG_R14 = 6,
610     X86_REG_R15 = 7,
611     X86_REG_EDI = 8,
612     X86_REG_ESI = 9,
613     X86_REG_EBP = 10,
614     X86_REG_EBX = 11,
615     X86_REG_EDX = 12,
616     X86_REG_EAX = 13,
617     X86_REG_ECX = 14,
618     X86_REG_ESP = 15,
619     X86_REG_EIP = 16
620     #endif
621 gbeauche 1.10 };
622     #endif
623 gbeauche 1.17 #if defined(__NetBSD__) || defined(__FreeBSD__)
624     enum {
625 gbeauche 1.34 #if (defined(i386) || defined(__i386__))
626 gbeauche 1.17 X86_REG_EIP = 10,
627     X86_REG_EAX = 7,
628     X86_REG_ECX = 6,
629     X86_REG_EDX = 5,
630     X86_REG_EBX = 4,
631     X86_REG_ESP = 13,
632     X86_REG_EBP = 2,
633     X86_REG_ESI = 1,
634     X86_REG_EDI = 0
635 gbeauche 1.34 #endif
636 gbeauche 1.17 };
637     #endif
638 gbeauche 1.10 // FIXME: this is partly redundant with the instruction decoding phase
639     // to discover transfer type and register number
640     static inline int ix86_step_over_modrm(unsigned char * p)
641     {
642     int mod = (p[0] >> 6) & 3;
643     int rm = p[0] & 7;
644     int offset = 0;
645    
646     // ModR/M Byte
647     switch (mod) {
648     case 0: // [reg]
649     if (rm == 5) return 4; // disp32
650     break;
651     case 1: // disp8[reg]
652     offset = 1;
653     break;
654     case 2: // disp32[reg]
655     offset = 4;
656     break;
657     case 3: // register
658     return 0;
659     }
660    
661     // SIB Byte
662     if (rm == 4) {
663     if (mod == 0 && (p[1] & 7) == 5)
664     offset = 5; // disp32[index]
665     else
666     offset++;
667     }
668    
669     return offset;
670     }
671    
672 gbeauche 1.34 static bool ix86_skip_instruction(unsigned long * regs)
673 gbeauche 1.10 {
674 gbeauche 1.14 unsigned char * eip = (unsigned char *)regs[X86_REG_EIP];
675 gbeauche 1.10
676     if (eip == 0)
677     return false;
678    
679 gbeauche 1.22 transfer_type_t transfer_type = SIGSEGV_TRANSFER_UNKNOWN;
680 gbeauche 1.14 transfer_size_t transfer_size = SIZE_LONG;
681 gbeauche 1.10
682     int reg = -1;
683     int len = 0;
684 gbeauche 1.34
685     #if DEBUG
686     printf("IP: %p [%02x %02x %02x %02x...]\n",
687     eip, eip[0], eip[1], eip[2], eip[3]);
688     #endif
689    
690 gbeauche 1.10 // Operand size prefix
691     if (*eip == 0x66) {
692     eip++;
693     len++;
694     transfer_size = SIZE_WORD;
695     }
696    
697 gbeauche 1.34 // REX prefix
698     #if defined(__x86_64__)
699     struct rex_t {
700     unsigned char W;
701     unsigned char R;
702     unsigned char X;
703     unsigned char B;
704     };
705     rex_t rex = { 0, 0, 0, 0 };
706     bool has_rex = false;
707     if ((*eip & 0xf0) == 0x40) {
708     has_rex = true;
709     const unsigned char b = *eip;
710     rex.W = b & (1 << 3);
711     rex.R = b & (1 << 2);
712     rex.X = b & (1 << 1);
713     rex.B = b & (1 << 0);
714     #if DEBUG
715     printf("REX: %c,%c,%c,%c\n",
716     rex.W ? 'W' : '_',
717     rex.R ? 'R' : '_',
718     rex.X ? 'X' : '_',
719     rex.B ? 'B' : '_');
720     #endif
721     eip++;
722     len++;
723     if (rex.W)
724     transfer_size = SIZE_QUAD;
725     }
726     #else
727     const bool has_rex = false;
728     #endif
729    
730 gbeauche 1.10 // Decode instruction
731     switch (eip[0]) {
732 gbeauche 1.17 case 0x0f:
733 gbeauche 1.18 switch (eip[1]) {
734     case 0xb6: // MOVZX r32, r/m8
735     case 0xb7: // MOVZX r32, r/m16
736 gbeauche 1.17 switch (eip[2] & 0xc0) {
737     case 0x80:
738     reg = (eip[2] >> 3) & 7;
739 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_LOAD;
740 gbeauche 1.17 break;
741     case 0x40:
742     reg = (eip[2] >> 3) & 7;
743 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_LOAD;
744 gbeauche 1.17 break;
745     case 0x00:
746     reg = (eip[2] >> 3) & 7;
747 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_LOAD;
748 gbeauche 1.17 break;
749     }
750     len += 3 + ix86_step_over_modrm(eip + 2);
751 gbeauche 1.18 break;
752 gbeauche 1.17 }
753     break;
754 gbeauche 1.10 case 0x8a: // MOV r8, r/m8
755     transfer_size = SIZE_BYTE;
756     case 0x8b: // MOV r32, r/m32 (or 16-bit operation)
757     switch (eip[1] & 0xc0) {
758     case 0x80:
759     reg = (eip[1] >> 3) & 7;
760 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_LOAD;
761 gbeauche 1.10 break;
762     case 0x40:
763     reg = (eip[1] >> 3) & 7;
764 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_LOAD;
765 gbeauche 1.10 break;
766     case 0x00:
767     reg = (eip[1] >> 3) & 7;
768 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_LOAD;
769 gbeauche 1.10 break;
770     }
771     len += 2 + ix86_step_over_modrm(eip + 1);
772     break;
773     case 0x88: // MOV r/m8, r8
774     transfer_size = SIZE_BYTE;
775     case 0x89: // MOV r/m32, r32 (or 16-bit operation)
776     switch (eip[1] & 0xc0) {
777     case 0x80:
778     reg = (eip[1] >> 3) & 7;
779 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_STORE;
780 gbeauche 1.10 break;
781     case 0x40:
782     reg = (eip[1] >> 3) & 7;
783 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_STORE;
784 gbeauche 1.10 break;
785     case 0x00:
786     reg = (eip[1] >> 3) & 7;
787 gbeauche 1.22 transfer_type = SIGSEGV_TRANSFER_STORE;
788 gbeauche 1.10 break;
789     }
790     len += 2 + ix86_step_over_modrm(eip + 1);
791     break;
792     }
793    
794 gbeauche 1.22 if (transfer_type == SIGSEGV_TRANSFER_UNKNOWN) {
795 gbeauche 1.10 // Unknown machine code, let it crash. Then patch the decoder
796     return false;
797     }
798    
799 gbeauche 1.34 #if defined(__x86_64__)
800     if (rex.R)
801     reg += 8;
802     #endif
803    
804 gbeauche 1.22 if (transfer_type == SIGSEGV_TRANSFER_LOAD && reg != -1) {
805 gbeauche 1.34 static const int x86_reg_map[] = {
806 gbeauche 1.10 X86_REG_EAX, X86_REG_ECX, X86_REG_EDX, X86_REG_EBX,
807 gbeauche 1.34 X86_REG_ESP, X86_REG_EBP, X86_REG_ESI, X86_REG_EDI,
808     #if defined(__x86_64__)
809     X86_REG_R8, X86_REG_R9, X86_REG_R10, X86_REG_R11,
810     X86_REG_R12, X86_REG_R13, X86_REG_R14, X86_REG_R15,
811     #endif
812 gbeauche 1.10 };
813    
814 gbeauche 1.34 if (reg < 0 || reg >= (sizeof(x86_reg_map)/sizeof(x86_reg_map[0]) - 1))
815 gbeauche 1.10 return false;
816    
817 gbeauche 1.34 // Set 0 to the relevant register part
818     // NOTE: this is only valid for MOV alike instructions
819 gbeauche 1.10 int rloc = x86_reg_map[reg];
820     switch (transfer_size) {
821     case SIZE_BYTE:
822 gbeauche 1.36 if (has_rex || reg < 4)
823     regs[rloc] = (regs[rloc] & ~0x00ffL);
824     else {
825     rloc = x86_reg_map[reg - 4];
826     regs[rloc] = (regs[rloc] & ~0xff00L);
827     }
828 gbeauche 1.10 break;
829     case SIZE_WORD:
830 gbeauche 1.34 regs[rloc] = (regs[rloc] & ~0xffffL);
831 gbeauche 1.10 break;
832     case SIZE_LONG:
833 gbeauche 1.34 case SIZE_QUAD: // zero-extension
834 gbeauche 1.10 regs[rloc] = 0;
835     break;
836     }
837     }
838    
839     #if DEBUG
840 gbeauche 1.15 printf("%08x: %s %s access", regs[X86_REG_EIP],
841 gbeauche 1.34 transfer_size == SIZE_BYTE ? "byte" :
842     transfer_size == SIZE_WORD ? "word" :
843     transfer_size == SIZE_LONG ? "long" :
844     transfer_size == SIZE_QUAD ? "quad" : "unknown",
845 gbeauche 1.22 transfer_type == SIGSEGV_TRANSFER_LOAD ? "read" : "write");
846 gbeauche 1.10
847     if (reg != -1) {
848 gbeauche 1.34 static const char * x86_byte_reg_str_map[] = {
849     "al", "cl", "dl", "bl",
850     "spl", "bpl", "sil", "dil",
851     "r8b", "r9b", "r10b", "r11b",
852     "r12b", "r13b", "r14b", "r15b",
853     "ah", "ch", "dh", "bh",
854     };
855     static const char * x86_word_reg_str_map[] = {
856     "ax", "cx", "dx", "bx",
857     "sp", "bp", "si", "di",
858     "r8w", "r9w", "r10w", "r11w",
859     "r12w", "r13w", "r14w", "r15w",
860     };
861     static const char *x86_long_reg_str_map[] = {
862     "eax", "ecx", "edx", "ebx",
863     "esp", "ebp", "esi", "edi",
864     "r8d", "r9d", "r10d", "r11d",
865     "r12d", "r13d", "r14d", "r15d",
866     };
867     static const char *x86_quad_reg_str_map[] = {
868     "rax", "rcx", "rdx", "rbx",
869     "rsp", "rbp", "rsi", "rdi",
870     "r8", "r9", "r10", "r11",
871     "r12", "r13", "r14", "r15",
872 gbeauche 1.10 };
873 gbeauche 1.34 const char * reg_str = NULL;
874     switch (transfer_size) {
875     case SIZE_BYTE:
876     reg_str = x86_byte_reg_str_map[(!has_rex && reg >= 4 ? 12 : 0) + reg];
877     break;
878     case SIZE_WORD: reg_str = x86_word_reg_str_map[reg]; break;
879     case SIZE_LONG: reg_str = x86_long_reg_str_map[reg]; break;
880     case SIZE_QUAD: reg_str = x86_quad_reg_str_map[reg]; break;
881     }
882     if (reg_str)
883     printf(" %s register %%%s",
884     transfer_type == SIGSEGV_TRANSFER_LOAD ? "to" : "from",
885     reg_str);
886 gbeauche 1.10 }
887     printf(", %d bytes instruction\n", len);
888     #endif
889    
890     regs[X86_REG_EIP] += len;
891 gbeauche 1.13 return true;
892     }
893     #endif
894 gbeauche 1.14
895 gbeauche 1.13 // Decode and skip PPC instruction
896 gbeauche 1.14 #if (defined(powerpc) || defined(__powerpc__) || defined(__ppc__))
897     static bool powerpc_skip_instruction(unsigned int * nip_p, unsigned int * regs)
898 gbeauche 1.13 {
899 gbeauche 1.14 instruction_t instr;
900     powerpc_decode_instruction(&instr, *nip_p, regs);
901 gbeauche 1.13
902 gbeauche 1.22 if (instr.transfer_type == SIGSEGV_TRANSFER_UNKNOWN) {
903 gbeauche 1.13 // Unknown machine code, let it crash. Then patch the decoder
904     return false;
905     }
906    
907     #if DEBUG
908 gbeauche 1.14 printf("%08x: %s %s access", *nip_p,
909     instr.transfer_size == SIZE_BYTE ? "byte" : instr.transfer_size == SIZE_WORD ? "word" : "long",
910 gbeauche 1.22 instr.transfer_type == SIGSEGV_TRANSFER_LOAD ? "read" : "write");
911 gbeauche 1.14
912     if (instr.addr_mode == MODE_U || instr.addr_mode == MODE_UX)
913     printf(" r%d (ra = %08x)\n", instr.ra, instr.addr);
914 gbeauche 1.22 if (instr.transfer_type == SIGSEGV_TRANSFER_LOAD)
915 gbeauche 1.14 printf(" r%d (rd = 0)\n", instr.rd);
916     #endif
917    
918     if (instr.addr_mode == MODE_U || instr.addr_mode == MODE_UX)
919     regs[instr.ra] = instr.addr;
920 gbeauche 1.22 if (instr.transfer_type == SIGSEGV_TRANSFER_LOAD)
921 gbeauche 1.14 regs[instr.rd] = 0;
922 gbeauche 1.13
923 gbeauche 1.14 *nip_p += 4;
924 gbeauche 1.10 return true;
925     }
926     #endif
927     #endif
928    
929 gbeauche 1.1 // Fallbacks
930     #ifndef SIGSEGV_FAULT_INSTRUCTION
931     #define SIGSEGV_FAULT_INSTRUCTION SIGSEGV_INVALID_PC
932     #endif
933 gbeauche 1.30 #ifndef SIGSEGV_FAULT_HANDLER_ARGLIST_1
934     #define SIGSEGV_FAULT_HANDLER_ARGLIST_1 SIGSEGV_FAULT_HANDLER_ARGLIST
935     #endif
936 gbeauche 1.31 #ifndef SIGSEGV_FAULT_HANDLER_INVOKE
937     #define SIGSEGV_FAULT_HANDLER_INVOKE(ADDR, IP) sigsegv_fault_handler(ADDR, IP)
938     #endif
939 gbeauche 1.1
940 gbeauche 1.2 // SIGSEGV recovery supported ?
941     #if defined(SIGSEGV_ALL_SIGNALS) && defined(SIGSEGV_FAULT_HANDLER_ARGLIST) && defined(SIGSEGV_FAULT_ADDRESS)
942     #define HAVE_SIGSEGV_RECOVERY
943     #endif
944    
945 gbeauche 1.1
946     /*
947     * SIGSEGV global handler
948     */
949    
950 gbeauche 1.27 #if defined(HAVE_SIGSEGV_RECOVERY) || defined(HAVE_MACH_EXCEPTIONS)
951     // This function handles the badaccess to memory.
952     // It is called from the signal handler or the exception handler.
953 gbeauche 1.30 static bool handle_badaccess(SIGSEGV_FAULT_HANDLER_ARGLIST_1)
954 gbeauche 1.1 {
955 gbeauche 1.10 sigsegv_address_t fault_address = (sigsegv_address_t)SIGSEGV_FAULT_ADDRESS;
956     sigsegv_address_t fault_instruction = (sigsegv_address_t)SIGSEGV_FAULT_INSTRUCTION;
957    
958 gbeauche 1.1 // Call user's handler and reinstall the global handler, if required
959 gbeauche 1.31 switch (SIGSEGV_FAULT_HANDLER_INVOKE(fault_address, fault_instruction)) {
960 gbeauche 1.24 case SIGSEGV_RETURN_SUCCESS:
961 gbeauche 1.27 return true;
962    
963 gbeauche 1.10 #if HAVE_SIGSEGV_SKIP_INSTRUCTION
964 gbeauche 1.24 case SIGSEGV_RETURN_SKIP_INSTRUCTION:
965 gbeauche 1.27 // Call the instruction skipper with the register file
966     // available
967     if (SIGSEGV_SKIP_INSTRUCTION(SIGSEGV_REGISTER_FILE)) {
968     #ifdef HAVE_MACH_EXCEPTIONS
969     // Unlike UNIX signals where the thread state
970     // is modified off of the stack, in Mach we
971     // need to actually call thread_set_state to
972     // have the register values updated.
973     kern_return_t krc;
974    
975     krc = thread_set_state(thread,
976     MACHINE_THREAD_STATE, (thread_state_t)state,
977     MACHINE_THREAD_STATE_COUNT);
978     MACH_CHECK_ERROR (thread_get_state, krc);
979     #endif
980     return true;
981     }
982 gbeauche 1.24 break;
983     #endif
984 gbeauche 1.10 }
985 gbeauche 1.27
986     // We can't do anything with the fault_address, dump state?
987     if (sigsegv_state_dumper != 0)
988     sigsegv_state_dumper(fault_address, fault_instruction);
989    
990     return false;
991     }
992     #endif
993    
994    
995     /*
996     * There are two mechanisms for handling a bad memory access,
997     * Mach exceptions and UNIX signals. The implementation specific
998     * code appears below. Its reponsibility is to call handle_badaccess
999     * which is the routine that handles the fault in an implementation
1000     * agnostic manner. The implementation specific code below is then
1001     * reponsible for checking whether handle_badaccess was able
1002     * to handle the memory access error and perform any implementation
1003     * specific tasks necessary afterwards.
1004     */
1005    
1006     #ifdef HAVE_MACH_EXCEPTIONS
1007     /*
1008     * We need to forward all exceptions that we do not handle.
1009     * This is important, there are many exceptions that may be
1010     * handled by other exception handlers. For example debuggers
1011     * use exceptions and the exception hander is in another
1012     * process in such a case. (Timothy J. Wood states in his
1013     * message to the list that he based this code on that from
1014     * gdb for Darwin.)
1015     */
1016     static inline kern_return_t
1017     forward_exception(mach_port_t thread_port,
1018     mach_port_t task_port,
1019     exception_type_t exception_type,
1020     exception_data_t exception_data,
1021     mach_msg_type_number_t data_count,
1022     ExceptionPorts *oldExceptionPorts)
1023     {
1024     kern_return_t kret;
1025     unsigned int portIndex;
1026     mach_port_t port;
1027     exception_behavior_t behavior;
1028     thread_state_flavor_t flavor;
1029     thread_state_t thread_state;
1030     mach_msg_type_number_t thread_state_count;
1031    
1032     for (portIndex = 0; portIndex < oldExceptionPorts->maskCount; portIndex++) {
1033     if (oldExceptionPorts->masks[portIndex] & (1 << exception_type)) {
1034     // This handler wants the exception
1035     break;
1036     }
1037     }
1038    
1039     if (portIndex >= oldExceptionPorts->maskCount) {
1040     fprintf(stderr, "No handler for exception_type = %d. Not fowarding\n", exception_type);
1041     return KERN_FAILURE;
1042     }
1043    
1044     port = oldExceptionPorts->handlers[portIndex];
1045     behavior = oldExceptionPorts->behaviors[portIndex];
1046     flavor = oldExceptionPorts->flavors[portIndex];
1047    
1048     /*
1049     fprintf(stderr, "forwarding exception, port = 0x%x, behaviour = %d, flavor = %d\n", port, behavior, flavor);
1050     */
1051    
1052     if (behavior != EXCEPTION_DEFAULT) {
1053     thread_state_count = THREAD_STATE_MAX;
1054     kret = thread_get_state (thread_port, flavor, thread_state,
1055     &thread_state_count);
1056     MACH_CHECK_ERROR (thread_get_state, kret);
1057     }
1058    
1059     switch (behavior) {
1060     case EXCEPTION_DEFAULT:
1061     // fprintf(stderr, "forwarding to exception_raise\n");
1062     kret = exception_raise(port, thread_port, task_port, exception_type,
1063     exception_data, data_count);
1064     MACH_CHECK_ERROR (exception_raise, kret);
1065     break;
1066     case EXCEPTION_STATE:
1067     // fprintf(stderr, "forwarding to exception_raise_state\n");
1068     kret = exception_raise_state(port, exception_type, exception_data,
1069     data_count, &flavor,
1070     thread_state, thread_state_count,
1071     thread_state, &thread_state_count);
1072     MACH_CHECK_ERROR (exception_raise_state, kret);
1073     break;
1074     case EXCEPTION_STATE_IDENTITY:
1075     // fprintf(stderr, "forwarding to exception_raise_state_identity\n");
1076     kret = exception_raise_state_identity(port, thread_port, task_port,
1077     exception_type, exception_data,
1078     data_count, &flavor,
1079     thread_state, thread_state_count,
1080     thread_state, &thread_state_count);
1081     MACH_CHECK_ERROR (exception_raise_state_identity, kret);
1082     break;
1083     default:
1084     fprintf(stderr, "forward_exception got unknown behavior\n");
1085     break;
1086     }
1087    
1088     if (behavior != EXCEPTION_DEFAULT) {
1089     kret = thread_set_state (thread_port, flavor, thread_state,
1090     thread_state_count);
1091     MACH_CHECK_ERROR (thread_set_state, kret);
1092     }
1093    
1094     return KERN_SUCCESS;
1095     }
1096    
1097     /*
1098     * This is the code that actually handles the exception.
1099     * It is called by exc_server. For Darwin 5 Apple changed
1100     * this a bit from how this family of functions worked in
1101     * Mach. If you are familiar with that it is a little
1102     * different. The main variation that concerns us here is
1103     * that code is an array of exception specific codes and
1104     * codeCount is a count of the number of codes in the code
1105     * array. In typical Mach all exceptions have a code
1106     * and sub-code. It happens to be the case that for a
1107     * EXC_BAD_ACCESS exception the first entry is the type of
1108     * bad access that occurred and the second entry is the
1109     * faulting address so these entries correspond exactly to
1110     * how the code and sub-code are used on Mach.
1111     *
1112     * This is a MIG interface. No code in Basilisk II should
1113     * call this directley. This has to have external C
1114     * linkage because that is what exc_server expects.
1115     */
1116     kern_return_t
1117     catch_exception_raise(mach_port_t exception_port,
1118     mach_port_t thread,
1119     mach_port_t task,
1120     exception_type_t exception,
1121     exception_data_t code,
1122     mach_msg_type_number_t codeCount)
1123     {
1124     ppc_thread_state_t state;
1125     kern_return_t krc;
1126    
1127     if ((exception == EXC_BAD_ACCESS) && (codeCount >= 2)) {
1128     if (handle_badaccess(SIGSEGV_FAULT_HANDLER_ARGS))
1129     return KERN_SUCCESS;
1130     }
1131    
1132     // In Mach we do not need to remove the exception handler.
1133     // If we forward the exception, eventually some exception handler
1134     // will take care of this exception.
1135     krc = forward_exception(thread, task, exception, code, codeCount, &ports);
1136    
1137     return krc;
1138     }
1139     #endif
1140    
1141     #ifdef HAVE_SIGSEGV_RECOVERY
1142     // Handle bad memory accesses with signal handler
1143     static void sigsegv_handler(SIGSEGV_FAULT_HANDLER_ARGLIST)
1144     {
1145     // Call handler and reinstall the global handler, if required
1146     if (handle_badaccess(SIGSEGV_FAULT_HANDLER_ARGS)) {
1147     #if (defined(HAVE_SIGACTION) ? defined(SIGACTION_NEED_REINSTALL) : defined(SIGNAL_NEED_REINSTALL))
1148     sigsegv_do_install_handler(sig);
1149     #endif
1150     return;
1151     }
1152 gbeauche 1.10
1153 gbeauche 1.27 // Failure: reinstall default handler for "safe" crash
1154 gbeauche 1.1 #define FAULT_HANDLER(sig) signal(sig, SIG_DFL);
1155 gbeauche 1.27 SIGSEGV_ALL_SIGNALS
1156 gbeauche 1.1 #undef FAULT_HANDLER
1157     }
1158 gbeauche 1.2 #endif
1159 gbeauche 1.1
1160    
1161     /*
1162     * SIGSEGV handler initialization
1163     */
1164    
1165     #if defined(HAVE_SIGINFO_T)
1166     static bool sigsegv_do_install_handler(int sig)
1167     {
1168     // Setup SIGSEGV handler to process writes to frame buffer
1169     #ifdef HAVE_SIGACTION
1170 gbeauche 1.22 struct sigaction sigsegv_sa;
1171     sigemptyset(&sigsegv_sa.sa_mask);
1172     sigsegv_sa.sa_sigaction = sigsegv_handler;
1173     sigsegv_sa.sa_flags = SA_SIGINFO;
1174     return (sigaction(sig, &sigsegv_sa, 0) == 0);
1175 gbeauche 1.1 #else
1176     return (signal(sig, (signal_handler)sigsegv_handler) != SIG_ERR);
1177     #endif
1178     }
1179 gbeauche 1.2 #endif
1180    
1181     #if defined(HAVE_SIGCONTEXT_SUBTERFUGE)
1182 gbeauche 1.1 static bool sigsegv_do_install_handler(int sig)
1183     {
1184     // Setup SIGSEGV handler to process writes to frame buffer
1185     #ifdef HAVE_SIGACTION
1186 gbeauche 1.22 struct sigaction sigsegv_sa;
1187     sigemptyset(&sigsegv_sa.sa_mask);
1188     sigsegv_sa.sa_handler = (signal_handler)sigsegv_handler;
1189     sigsegv_sa.sa_flags = 0;
1190 gbeauche 1.1 #if !EMULATED_68K && defined(__NetBSD__)
1191 gbeauche 1.22 sigaddset(&sigsegv_sa.sa_mask, SIGALRM);
1192     sigsegv_sa.sa_flags |= SA_ONSTACK;
1193 gbeauche 1.1 #endif
1194 gbeauche 1.22 return (sigaction(sig, &sigsegv_sa, 0) == 0);
1195 gbeauche 1.1 #else
1196     return (signal(sig, (signal_handler)sigsegv_handler) != SIG_ERR);
1197     #endif
1198     }
1199     #endif
1200    
1201 gbeauche 1.27 #if defined(HAVE_MACH_EXCEPTIONS)
1202     static bool sigsegv_do_install_handler(sigsegv_fault_handler_t handler)
1203     {
1204     /*
1205     * Except for the exception port functions, this should be
1206     * pretty much stock Mach. If later you choose to support
1207     * other Mach's besides Darwin, just check for __MACH__
1208     * here and __APPLE__ where the actual differences are.
1209     */
1210     #if defined(__APPLE__) && defined(__MACH__)
1211     if (sigsegv_fault_handler != NULL) {
1212     sigsegv_fault_handler = handler;
1213     return true;
1214     }
1215    
1216     kern_return_t krc;
1217    
1218     // create the the exception port
1219     krc = mach_port_allocate(mach_task_self(),
1220     MACH_PORT_RIGHT_RECEIVE, &_exceptionPort);
1221     if (krc != KERN_SUCCESS) {
1222     mach_error("mach_port_allocate", krc);
1223     return false;
1224     }
1225    
1226     // add a port send right
1227     krc = mach_port_insert_right(mach_task_self(),
1228     _exceptionPort, _exceptionPort,
1229     MACH_MSG_TYPE_MAKE_SEND);
1230     if (krc != KERN_SUCCESS) {
1231     mach_error("mach_port_insert_right", krc);
1232     return false;
1233     }
1234    
1235     // get the old exception ports
1236     ports.maskCount = sizeof (ports.masks) / sizeof (ports.masks[0]);
1237     krc = thread_get_exception_ports(mach_thread_self(), EXC_MASK_BAD_ACCESS, ports.masks,
1238     &ports.maskCount, ports.handlers, ports.behaviors, ports.flavors);
1239     if (krc != KERN_SUCCESS) {
1240     mach_error("thread_get_exception_ports", krc);
1241     return false;
1242     }
1243    
1244     // set the new exception port
1245     //
1246     // We could have used EXCEPTION_STATE_IDENTITY instead of
1247     // EXCEPTION_DEFAULT to get the thread state in the initial
1248     // message, but it turns out that in the common case this is not
1249     // neccessary. If we need it we can later ask for it from the
1250     // suspended thread.
1251     //
1252     // Even with THREAD_STATE_NONE, Darwin provides the program
1253     // counter in the thread state. The comments in the header file
1254     // seem to imply that you can count on the GPR's on an exception
1255     // as well but just to be safe I use MACHINE_THREAD_STATE because
1256     // you have to ask for all of the GPR's anyway just to get the
1257     // program counter. In any case because of update effective
1258     // address from immediate and update address from effective
1259     // addresses of ra and rb modes (as good an name as any for these
1260     // addressing modes) used in PPC instructions, you will need the
1261     // GPR state anyway.
1262     krc = thread_set_exception_ports(mach_thread_self(), EXC_MASK_BAD_ACCESS, _exceptionPort,
1263     EXCEPTION_DEFAULT, MACHINE_THREAD_STATE);
1264     if (krc != KERN_SUCCESS) {
1265     mach_error("thread_set_exception_ports", krc);
1266     return false;
1267     }
1268    
1269     // create the exception handler thread
1270     if (pthread_create(&exc_thread, NULL, &handleExceptions, NULL) != 0) {
1271     (void)fprintf(stderr, "creation of exception thread failed\n");
1272     return false;
1273     }
1274    
1275     // do not care about the exception thread any longer, let is run standalone
1276     (void)pthread_detach(exc_thread);
1277    
1278     sigsegv_fault_handler = handler;
1279     return true;
1280     #else
1281     return false;
1282     #endif
1283     }
1284     #endif
1285    
1286 gbeauche 1.12 bool sigsegv_install_handler(sigsegv_fault_handler_t handler)
1287 gbeauche 1.1 {
1288 gbeauche 1.27 #if defined(HAVE_SIGSEGV_RECOVERY)
1289 gbeauche 1.1 bool success = true;
1290     #define FAULT_HANDLER(sig) success = success && sigsegv_do_install_handler(sig);
1291     SIGSEGV_ALL_SIGNALS
1292     #undef FAULT_HANDLER
1293 gbeauche 1.27 if (success)
1294     sigsegv_fault_handler = handler;
1295 gbeauche 1.1 return success;
1296 gbeauche 1.27 #elif defined(HAVE_MACH_EXCEPTIONS)
1297     return sigsegv_do_install_handler(handler);
1298 gbeauche 1.1 #else
1299     // FAIL: no siginfo_t nor sigcontext subterfuge is available
1300     return false;
1301     #endif
1302     }
1303    
1304    
1305     /*
1306     * SIGSEGV handler deinitialization
1307     */
1308    
1309     void sigsegv_deinstall_handler(void)
1310     {
1311 gbeauche 1.27 // We do nothing for Mach exceptions, the thread would need to be
1312     // suspended if not already so, and we might mess with other
1313     // exception handlers that came after we registered ours. There is
1314     // no need to remove the exception handler, in fact this function is
1315     // not called anywhere in Basilisk II.
1316 gbeauche 1.2 #ifdef HAVE_SIGSEGV_RECOVERY
1317 gbeauche 1.12 sigsegv_fault_handler = 0;
1318 gbeauche 1.1 #define FAULT_HANDLER(sig) signal(sig, SIG_DFL);
1319     SIGSEGV_ALL_SIGNALS
1320     #undef FAULT_HANDLER
1321 gbeauche 1.2 #endif
1322 gbeauche 1.1 }
1323    
1324 gbeauche 1.10
1325     /*
1326     * Set callback function when we cannot handle the fault
1327     */
1328    
1329 gbeauche 1.12 void sigsegv_set_dump_state(sigsegv_state_dumper_t handler)
1330 gbeauche 1.10 {
1331 gbeauche 1.12 sigsegv_state_dumper = handler;
1332 gbeauche 1.10 }
1333    
1334    
1335 gbeauche 1.1 /*
1336     * Test program used for configure/test
1337     */
1338    
1339 gbeauche 1.4 #ifdef CONFIGURE_TEST_SIGSEGV_RECOVERY
1340 gbeauche 1.1 #include <stdio.h>
1341     #include <stdlib.h>
1342     #include <fcntl.h>
1343     #include <sys/mman.h>
1344 gbeauche 1.4 #include "vm_alloc.h"
1345 gbeauche 1.1
1346 gbeauche 1.32 const int REF_INDEX = 123;
1347     const int REF_VALUE = 45;
1348    
1349 gbeauche 1.1 static int page_size;
1350 gbeauche 1.3 static volatile char * page = 0;
1351     static volatile int handler_called = 0;
1352 gbeauche 1.1
1353 gbeauche 1.32 #ifdef __GNUC__
1354     // Code range where we expect the fault to come from
1355     static void *b_region, *e_region;
1356     #endif
1357    
1358 gbeauche 1.24 static sigsegv_return_t sigsegv_test_handler(sigsegv_address_t fault_address, sigsegv_address_t instruction_address)
1359 gbeauche 1.1 {
1360     handler_called++;
1361 gbeauche 1.32 if ((fault_address - REF_INDEX) != page)
1362 gbeauche 1.29 exit(10);
1363 gbeauche 1.32 #ifdef __GNUC__
1364     // Make sure reported fault instruction address falls into
1365     // expected code range
1366     if (instruction_address != SIGSEGV_INVALID_PC
1367     && ((instruction_address < (sigsegv_address_t)b_region) ||
1368     (instruction_address >= (sigsegv_address_t)e_region)))
1369     exit(11);
1370     #endif
1371 gbeauche 1.4 if (vm_protect((char *)((unsigned long)fault_address & -page_size), page_size, VM_PAGE_READ | VM_PAGE_WRITE) != 0)
1372 gbeauche 1.32 exit(12);
1373 gbeauche 1.24 return SIGSEGV_RETURN_SUCCESS;
1374 gbeauche 1.1 }
1375    
1376 gbeauche 1.10 #ifdef HAVE_SIGSEGV_SKIP_INSTRUCTION
1377 gbeauche 1.24 static sigsegv_return_t sigsegv_insn_handler(sigsegv_address_t fault_address, sigsegv_address_t instruction_address)
1378 gbeauche 1.10 {
1379 gbeauche 1.28 if (((unsigned long)fault_address - (unsigned long)page) < page_size) {
1380     #ifdef __GNUC__
1381     // Make sure reported fault instruction address falls into
1382     // expected code range
1383     if (instruction_address != SIGSEGV_INVALID_PC
1384     && ((instruction_address < (sigsegv_address_t)b_region) ||
1385     (instruction_address >= (sigsegv_address_t)e_region)))
1386     return SIGSEGV_RETURN_FAILURE;
1387     #endif
1388 gbeauche 1.26 return SIGSEGV_RETURN_SKIP_INSTRUCTION;
1389 gbeauche 1.28 }
1390    
1391 gbeauche 1.24 return SIGSEGV_RETURN_FAILURE;
1392 gbeauche 1.10 }
1393 gbeauche 1.34
1394     // More sophisticated tests for instruction skipper
1395     static bool arch_insn_skipper_tests()
1396     {
1397     #if (defined(i386) || defined(__i386__)) || defined(__x86_64__)
1398     static const unsigned char code[] = {
1399     0x8a, 0x00, // mov (%eax),%al
1400     0x8a, 0x2c, 0x18, // mov (%eax,%ebx,1),%ch
1401     0x88, 0x20, // mov %ah,(%eax)
1402     0x88, 0x08, // mov %cl,(%eax)
1403     0x66, 0x8b, 0x00, // mov (%eax),%ax
1404     0x66, 0x8b, 0x0c, 0x18, // mov (%eax,%ebx,1),%cx
1405     0x66, 0x89, 0x00, // mov %ax,(%eax)
1406     0x66, 0x89, 0x0c, 0x18, // mov %cx,(%eax,%ebx,1)
1407     0x8b, 0x00, // mov (%eax),%eax
1408     0x8b, 0x0c, 0x18, // mov (%eax,%ebx,1),%ecx
1409     0x89, 0x00, // mov %eax,(%eax)
1410     0x89, 0x0c, 0x18, // mov %ecx,(%eax,%ebx,1)
1411     #if defined(__x86_64__)
1412     0x44, 0x8a, 0x00, // mov (%rax),%r8b
1413     0x44, 0x8a, 0x20, // mov (%rax),%r12b
1414     0x42, 0x8a, 0x3c, 0x10, // mov (%rax,%r10,1),%dil
1415     0x44, 0x88, 0x00, // mov %r8b,(%rax)
1416     0x44, 0x88, 0x20, // mov %r12b,(%rax)
1417     0x42, 0x88, 0x3c, 0x10, // mov %dil,(%rax,%r10,1)
1418     0x66, 0x44, 0x8b, 0x00, // mov (%rax),%r8w
1419     0x66, 0x42, 0x8b, 0x0c, 0x10, // mov (%rax,%r10,1),%cx
1420     0x66, 0x44, 0x89, 0x00, // mov %r8w,(%rax)
1421     0x66, 0x42, 0x89, 0x0c, 0x10, // mov %cx,(%rax,%r10,1)
1422     0x44, 0x8b, 0x00, // mov (%rax),%r8d
1423     0x42, 0x8b, 0x0c, 0x10, // mov (%rax,%r10,1),%ecx
1424     0x44, 0x89, 0x00, // mov %r8d,(%rax)
1425     0x42, 0x89, 0x0c, 0x10, // mov %ecx,(%rax,%r10,1)
1426     0x48, 0x8b, 0x08, // mov (%rax),%rcx
1427     0x4c, 0x8b, 0x18, // mov (%rax),%r11
1428     0x4a, 0x8b, 0x0c, 0x10, // mov (%rax,%r10,1),%rcx
1429     0x4e, 0x8b, 0x1c, 0x10, // mov (%rax,%r10,1),%r11
1430     0x48, 0x89, 0x08, // mov %rcx,(%rax)
1431     0x4c, 0x89, 0x18, // mov %r11,(%rax)
1432     0x4a, 0x89, 0x0c, 0x10, // mov %rcx,(%rax,%r10,1)
1433     0x4e, 0x89, 0x1c, 0x10, // mov %r11,(%rax,%r10,1)
1434     #endif
1435     0 // end
1436     };
1437     const int N_REGS = 20;
1438     unsigned long regs[N_REGS];
1439     for (int i = 0; i < N_REGS; i++)
1440     regs[i] = i;
1441     const unsigned long start_code = (unsigned long)&code;
1442     regs[X86_REG_EIP] = start_code;
1443     while ((regs[X86_REG_EIP] - start_code) < (sizeof(code) - 1)
1444     && ix86_skip_instruction(regs))
1445     ; /* simply iterate */
1446     return (regs[X86_REG_EIP] - start_code) == (sizeof(code) - 1);
1447     #endif
1448     return true;
1449     }
1450 gbeauche 1.10 #endif
1451    
1452 gbeauche 1.1 int main(void)
1453     {
1454 gbeauche 1.4 if (vm_init() < 0)
1455 gbeauche 1.1 return 1;
1456    
1457     page_size = getpagesize();
1458 gbeauche 1.4 if ((page = (char *)vm_acquire(page_size)) == VM_MAP_FAILED)
1459 gbeauche 1.29 return 2;
1460 gbeauche 1.4
1461 gbeauche 1.32 memset((void *)page, 0, page_size);
1462 gbeauche 1.4 if (vm_protect((char *)page, page_size, VM_PAGE_READ) < 0)
1463 gbeauche 1.29 return 3;
1464 gbeauche 1.1
1465     if (!sigsegv_install_handler(sigsegv_test_handler))
1466 gbeauche 1.29 return 4;
1467 gbeauche 1.1
1468 gbeauche 1.32 #ifdef __GNUC__
1469     b_region = &&L_b_region1;
1470     e_region = &&L_e_region1;
1471     #endif
1472     L_b_region1:
1473     page[REF_INDEX] = REF_VALUE;
1474     if (page[REF_INDEX] != REF_VALUE)
1475     exit(20);
1476     page[REF_INDEX] = REF_VALUE;
1477     L_e_region1:
1478    
1479 gbeauche 1.1 if (handler_called != 1)
1480 gbeauche 1.29 return 5;
1481 gbeauche 1.10
1482     #ifdef HAVE_SIGSEGV_SKIP_INSTRUCTION
1483     if (!sigsegv_install_handler(sigsegv_insn_handler))
1484 gbeauche 1.29 return 6;
1485 gbeauche 1.10
1486 gbeauche 1.17 if (vm_protect((char *)page, page_size, VM_PAGE_READ | VM_PAGE_WRITE) < 0)
1487 gbeauche 1.29 return 7;
1488 gbeauche 1.10
1489     for (int i = 0; i < page_size; i++)
1490     page[i] = (i + 1) % page_size;
1491    
1492     if (vm_protect((char *)page, page_size, VM_PAGE_NOACCESS) < 0)
1493 gbeauche 1.29 return 8;
1494 gbeauche 1.10
1495     #define TEST_SKIP_INSTRUCTION(TYPE) do { \
1496 gbeauche 1.34 const unsigned long TAG = 0x12345678 | \
1497     (sizeof(long) == 8 ? 0x9abcdef0UL << 31 : 0); \
1498 gbeauche 1.10 TYPE data = *((TYPE *)(page + sizeof(TYPE))); \
1499 gbeauche 1.34 volatile unsigned long effect = data + TAG; \
1500 gbeauche 1.10 if (effect != TAG) \
1501 gbeauche 1.29 return 9; \
1502 gbeauche 1.10 } while (0)
1503    
1504 gbeauche 1.28 #ifdef __GNUC__
1505 gbeauche 1.32 b_region = &&L_b_region2;
1506     e_region = &&L_e_region2;
1507 gbeauche 1.28 #endif
1508 gbeauche 1.32 L_b_region2:
1509 gbeauche 1.10 TEST_SKIP_INSTRUCTION(unsigned char);
1510     TEST_SKIP_INSTRUCTION(unsigned short);
1511     TEST_SKIP_INSTRUCTION(unsigned int);
1512 gbeauche 1.34 TEST_SKIP_INSTRUCTION(unsigned long);
1513 gbeauche 1.32 L_e_region2:
1514 gbeauche 1.1
1515 gbeauche 1.34 if (!arch_insn_skipper_tests())
1516     return 20;
1517 gbeauche 1.35 #endif
1518 gbeauche 1.34
1519 gbeauche 1.4 vm_exit();
1520 gbeauche 1.1 return 0;
1521     }
1522     #endif