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root/cebix/BasiliskII/src/Unix/sigsegv.cpp

Comparing BasiliskII/src/Unix/sigsegv.cpp (file contents):
Revision 1.3 by gbeauche, 2001-06-05T12:16:34Z vs.
Revision 1.32 by gbeauche, 2003-10-21T21:59:41Z

#	Line 4 | Line 4
4		*  Derived from Bruno Haible's work on his SIGSEGV library for clisp
5		*  <http://clisp.sourceforge.net/>
6		*
7	<	*  Basilisk II (C) 1997-2001 Christian Bauer
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
16		*  it under the terms of the GNU General Public License as published by
#	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 41 | Line 52
52		typedef RETSIGTYPE (*signal_handler)(int);
53
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_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	+	#if defined(__NetBSD__) || defined(__FreeBSD__)
216	+	#define SIGSEGV_ALL_SIGNALS                             FAULT_HANDLER(SIGBUS)
217	+	#else
218		#define SIGSEGV_ALL_SIGNALS                             FAULT_HANDLER(SIGSEGV)
219	<	#define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, siginfo_t *sip, void *
219	>	#endif
220	>	#define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, siginfo_t *sip, void *scp
221	>	#define SIGSEGV_FAULT_HANDLER_ARGLIST_1 siginfo_t *sip, void *scp
222	>	#define SIGSEGV_FAULT_HANDLER_ARGS              sip, scp
223		#define SIGSEGV_FAULT_ADDRESS                   sip->si_addr
224	+	#if defined(__sun__)
225	+	#if (defined(sparc) || defined(__sparc__))
226	+	#include <sys/ucontext.h>
227	+	#define SIGSEGV_CONTEXT_REGS                    (((ucontext_t *)scp)->uc_mcontext.gregs)
228	+	#define SIGSEGV_FAULT_INSTRUCTION               SIGSEGV_CONTEXT_REGS[REG_PC]
229	+	#endif
230	+	#endif
231	+	#if defined(__NetBSD__) || defined(__FreeBSD__)
232	+	#if (defined(i386) || defined(__i386__))
233	+	#define SIGSEGV_FAULT_INSTRUCTION               (((struct sigcontext *)scp)->sc_eip)
234	+	#define SIGSEGV_REGISTER_FILE                   ((unsigned int *)&(((struct sigcontext *)scp)->sc_edi)) /* EDI is the first GPR (even below EIP) in sigcontext */
235	+	#define SIGSEGV_SKIP_INSTRUCTION                ix86_skip_instruction
236	+	#endif
237	+	#endif
238	+	#if defined(__linux__)
239	+	#if (defined(i386) || defined(__i386__))
240	+	#include <sys/ucontext.h>
241	+	#define SIGSEGV_CONTEXT_REGS                    (((ucontext_t *)scp)->uc_mcontext.gregs)
242	+	#define SIGSEGV_FAULT_INSTRUCTION               SIGSEGV_CONTEXT_REGS[14] /* should use REG_EIP instead */
243	+	#define SIGSEGV_REGISTER_FILE                   (unsigned int *)SIGSEGV_CONTEXT_REGS
244	+	#define SIGSEGV_SKIP_INSTRUCTION                ix86_skip_instruction
245	+	#endif
246	+	#if (defined(x86_64) || defined(__x86_64__))
247	+	#include <sys/ucontext.h>
248	+	#define SIGSEGV_CONTEXT_REGS                    (((ucontext_t *)scp)->uc_mcontext.gregs)
249	+	#define SIGSEGV_FAULT_INSTRUCTION               SIGSEGV_CONTEXT_REGS[16] /* should use REG_RIP instead */
250	+	#define SIGSEGV_REGISTER_FILE                   (unsigned long *)SIGSEGV_CONTEXT_REGS
251	+	#endif
252	+	#if (defined(ia64) || defined(__ia64__))
253	+	#define SIGSEGV_FAULT_INSTRUCTION               (((struct sigcontext *)scp)->sc_ip & ~0x3ULL) /* slot number is in bits 0 and 1 */
254	+	#endif
255	+	#if (defined(powerpc) || defined(__powerpc__))
256	+	#include <sys/ucontext.h>
257	+	#define SIGSEGV_CONTEXT_REGS                    (((ucontext_t *)scp)->uc_mcontext.regs)
258	+	#define SIGSEGV_FAULT_INSTRUCTION               (SIGSEGV_CONTEXT_REGS->nip)
259	+	#define SIGSEGV_REGISTER_FILE                   (unsigned int *)&SIGSEGV_CONTEXT_REGS->nip, (unsigned int *)(SIGSEGV_CONTEXT_REGS->gpr)
260	+	#define SIGSEGV_SKIP_INSTRUCTION                powerpc_skip_instruction
261	+	#endif
262	+	#endif
263		#endif
264
265		#if HAVE_SIGCONTEXT_SUBTERFUGE
#	Line 65 | Line 269 | static bool sigsegv_do_install_handler(i
269		#if (defined(i386) || defined(__i386__))
270		#include <asm/sigcontext.h>
271		#define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, struct sigcontext scs
272	<	#define SIGSEGV_FAULT_ADDRESS                   scs.cr2
273	<	#define SIGSEGV_FAULT_INSTRUCTION               scs.eip
272	>	#define SIGSEGV_FAULT_HANDLER_ARGLIST_1 struct sigcontext *scp
273	>	#define SIGSEGV_FAULT_HANDLER_ARGS              &scs
274	>	#define SIGSEGV_FAULT_ADDRESS                   scp->cr2
275	>	#define SIGSEGV_FAULT_INSTRUCTION               scp->eip
276	>	#define SIGSEGV_REGISTER_FILE                   (unsigned int *)scp
277	>	#define SIGSEGV_SKIP_INSTRUCTION                ix86_skip_instruction
278		#endif
279		#if (defined(sparc) || defined(__sparc__))
280		#include <asm/sigcontext.h>
281	<	#define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, int code, struct sigcontext* scp, char* addr
281	>	#define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, int code, struct sigcontext *scp, char *addr
282	>	#define SIGSEGV_FAULT_HANDLER_ARGS              sig, code, scp, addr
283		#define SIGSEGV_FAULT_ADDRESS                   addr
284		#endif
285		#if (defined(powerpc) || defined(__powerpc__))
286		#include <asm/sigcontext.h>
287	<	#define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, struct sigcontext* scp
287	>	#define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, struct sigcontext *scp
288	>	#define SIGSEGV_FAULT_HANDLER_ARGS              sig, scp
289		#define SIGSEGV_FAULT_ADDRESS                   scp->regs->dar
290		#define SIGSEGV_FAULT_INSTRUCTION               scp->regs->nip
291	+	#define SIGSEGV_REGISTER_FILE                   (unsigned int *)&scp->regs->nip, (unsigned int *)(scp->regs->gpr)
292	+	#define SIGSEGV_SKIP_INSTRUCTION                powerpc_skip_instruction
293	+	#endif
294	+	#if (defined(alpha) || defined(__alpha__))
295	+	#include <asm/sigcontext.h>
296	+	#define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, int code, struct sigcontext *scp
297	+	#define SIGSEGV_FAULT_HANDLER_ARGS              sig, code, scp
298	+	#define SIGSEGV_FAULT_ADDRESS                   get_fault_address(scp)
299	+	#define SIGSEGV_FAULT_INSTRUCTION               scp->sc_pc
300	+
301	+	// From Boehm's GC 6.0alpha8
302	+	static sigsegv_address_t get_fault_address(struct sigcontext *scp)
303	+	{
304	+	unsigned int instruction = *((unsigned int *)(scp->sc_pc));
305	+	unsigned long fault_address = scp->sc_regs[(instruction >> 16) & 0x1f];
306	+	fault_address += (signed long)(signed short)(instruction & 0xffff);
307	+	return (sigsegv_address_t)fault_address;
308	+	}
309		#endif
310		#endif
311
312		// Irix 5 or 6 on MIPS
313		#if (defined(sgi) || defined(__sgi)) && (defined(SYSTYPE_SVR4) || defined(__SYSTYPE_SVR4))
314	+	#include <ucontext.h>
315		#define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, int code, struct sigcontext *scp
316	+	#define SIGSEGV_FAULT_HANDLER_ARGS              sig, code, scp
317		#define SIGSEGV_FAULT_ADDRESS                   scp->sc_badvaddr
318		#define SIGSEGV_ALL_SIGNALS                             FAULT_HANDLER(SIGSEGV)
319		#endif
320
321	+	// HP-UX
322	+	#if (defined(hpux) || defined(__hpux__))
323	+	#define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, int code, struct sigcontext *scp
324	+	#define SIGSEGV_FAULT_HANDLER_ARGS              sig, code, scp
325	+	#define SIGSEGV_FAULT_ADDRESS                   scp->sc_sl.sl_ss.ss_narrow.ss_cr21
326	+	#define SIGSEGV_ALL_SIGNALS                             FAULT_HANDLER(SIGSEGV) FAULT_HANDLER(SIGBUS)
327	+	#endif
328	+
329		// OSF/1 on Alpha
330		#if defined(__osf__)
331	+	#include <ucontext.h>
332		#define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, int code, struct sigcontext *scp
333	+	#define SIGSEGV_FAULT_HANDLER_ARGS              sig, code, scp
334		#define SIGSEGV_FAULT_ADDRESS                   scp->sc_traparg_a0
335		#define SIGSEGV_ALL_SIGNALS                             FAULT_HANDLER(SIGSEGV)
336		#endif
#	Line 98 | Line 338 | static bool sigsegv_do_install_handler(i
338		// AIX
339		#if defined(_AIX)
340		#define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, int code, struct sigcontext *scp
341	+	#define SIGSEGV_FAULT_HANDLER_ARGS              sig, code, scp
342		#define SIGSEGV_FAULT_ADDRESS                   scp->sc_jmpbuf.jmp_context.o_vaddr
343		#define SIGSEGV_ALL_SIGNALS                             FAULT_HANDLER(SIGSEGV)
344		#endif
#	Line 107 | Line 348 | static bool sigsegv_do_install_handler(i
348		#if (defined(m68k) || defined(__m68k__))
349		#include <m68k/frame.h>
350		#define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, int code, struct sigcontext *scp
351	<	#define SIGSEGV_FAULT_ADDRESS                   ({                                                                                                                              \
352	<	struct sigstate {                                                                                                                                                                       \
112	<	int ss_flags;                                                                                                                                                                   \
113	<	struct frame ss_frame;                                                                                                                                                  \
114	<	};                                                                                                                                                                                                      \
115	<	struct sigstate *state = (struct sigstate *)scp->sc_ap;                                                                                         \
116	<	char *fault_addr;                                                                                                                                                                       \
117	<	switch (state->ss_frame.f_format) {                                                                                                                                     \
118	<	case 7:         /* 68040 access error */                                                                                                                                \
119	<	/* "code" is sometimes unreliable (i.e. contains NULL or a bogus address), reason unknown */    \
120	<	fault_addr = state->ss_frame.f_fmt7.f_fa;                                                                                                               \
121	<	break;                                                                                                                                                                                  \
122	<	default:                                                                                                                                                                                        \
123	<	fault_addr = (char *)code;                                                                                                                                              \
124	<	break;                                                                                                                                                                                  \
125	<	}                                                                                                                                                                                                       \
126	<	fault_addr;                                                                                                                                                                                     \
127	<	})
351	>	#define SIGSEGV_FAULT_HANDLER_ARGS              sig, code, scp
352	>	#define SIGSEGV_FAULT_ADDRESS                   get_fault_address(scp)
353		#define SIGSEGV_ALL_SIGNALS                             FAULT_HANDLER(SIGSEGV)
354	+
355	+	// Use decoding scheme from BasiliskII/m68k native
356	+	static sigsegv_address_t get_fault_address(struct sigcontext *scp)
357	+	{
358	+	struct sigstate {
359	+	int ss_flags;
360	+	struct frame ss_frame;
361	+	};
362	+	struct sigstate *state = (struct sigstate *)scp->sc_ap;
363	+	char *fault_addr;
364	+	switch (state->ss_frame.f_format) {
365	+	case 7:         /* 68040 access error */
366	+	/* "code" is sometimes unreliable (i.e. contains NULL or a bogus address), reason unknown */
367	+	fault_addr = state->ss_frame.f_fmt7.f_fa;
368	+	break;
369	+	default:
370	+	fault_addr = (char *)code;
371	+	break;
372	+	}
373	+	return (sigsegv_address_t)fault_addr;
374	+	}
375		#else
376		#define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, int code, void *scp, char *addr
377	+	#define SIGSEGV_FAULT_HANDLER_ARGS              sig, code, scp, addr
378		#define SIGSEGV_FAULT_ADDRESS                   addr
379		#define SIGSEGV_ALL_SIGNALS                             FAULT_HANDLER(SIGBUS)
380		#endif
381		#endif
382	+
383	+	// MacOS X, not sure which version this works in. Under 10.1
384	+	// vm_protect does not appear to work from a signal handler. Under
385	+	// 10.2 signal handlers get siginfo type arguments but the si_addr
386	+	// field is the address of the faulting instruction and not the
387	+	// address that caused the SIGBUS. Maybe this works in 10.0? In any
388	+	// case with Mach exception handlers there is a way to do what this
389	+	// was meant to do.
390	+	#ifndef HAVE_MACH_EXCEPTIONS
391	+	#if defined(__APPLE__) && defined(__MACH__)
392	+	#if (defined(ppc) || defined(__ppc__))
393	+	#define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, int code, struct sigcontext *scp
394	+	#define SIGSEGV_FAULT_HANDLER_ARGS              sig, code, scp
395	+	#define SIGSEGV_FAULT_ADDRESS                   get_fault_address(scp)
396	+	#define SIGSEGV_FAULT_INSTRUCTION               scp->sc_ir
397	+	#define SIGSEGV_ALL_SIGNALS                             FAULT_HANDLER(SIGBUS)
398	+	#define SIGSEGV_REGISTER_FILE                   (unsigned int *)&scp->sc_ir, &((unsigned int *) scp->sc_regs)[2]
399	+	#define SIGSEGV_SKIP_INSTRUCTION                powerpc_skip_instruction
400	+
401	+	// Use decoding scheme from SheepShaver
402	+	static sigsegv_address_t get_fault_address(struct sigcontext *scp)
403	+	{
404	+	unsigned int   nip = (unsigned int) scp->sc_ir;
405	+	unsigned int * gpr = &((unsigned int *) scp->sc_regs)[2];
406	+	instruction_t  instr;
407	+
408	+	powerpc_decode_instruction(&instr, nip, gpr);
409	+	return (sigsegv_address_t)instr.addr;
410	+	}
411	+	#endif
412	+	#endif
413	+	#endif
414	+	#endif
415	+
416	+	#if HAVE_MACH_EXCEPTIONS
417	+
418	+	// This can easily be extended to other Mach systems, but really who
419	+	// uses HURD (oops GNU/HURD), Darwin/x86, NextStep, Rhapsody, or CMU
420	+	// Mach 2.5/3.0?
421	+	#if defined(__APPLE__) && defined(__MACH__)
422	+
423	+	#include <sys/types.h>
424	+	#include <stdlib.h>
425	+	#include <stdio.h>
426	+	#include <pthread.h>
427	+
428	+	/*
429	+	* If you are familiar with MIG then you will understand the frustration
430	+	* that was necessary to get these embedded into C++ code by hand.
431	+	*/
432	+	extern "C" {
433	+	#include <mach/mach.h>
434	+	#include <mach/mach_error.h>
435	+
436	+	extern boolean_t exc_server(mach_msg_header_t *, mach_msg_header_t *);
437	+	extern kern_return_t catch_exception_raise(mach_port_t, mach_port_t,
438	+	mach_port_t, exception_type_t, exception_data_t, mach_msg_type_number_t);
439	+	extern kern_return_t exception_raise(mach_port_t, mach_port_t, mach_port_t,
440	+	exception_type_t, exception_data_t, mach_msg_type_number_t);
441	+	extern kern_return_t exception_raise_state(mach_port_t, exception_type_t,
442	+	exception_data_t, mach_msg_type_number_t, thread_state_flavor_t *,
443	+	thread_state_t, mach_msg_type_number_t, thread_state_t, mach_msg_type_number_t *);
444	+	extern kern_return_t exception_raise_state_identity(mach_port_t, mach_port_t, mach_port_t,
445	+	exception_type_t, exception_data_t, mach_msg_type_number_t, thread_state_flavor_t *,
446	+	thread_state_t, mach_msg_type_number_t, thread_state_t, mach_msg_type_number_t *);
447	+	}
448	+
449	+	// Could make this dynamic by looking for a result of MIG_ARRAY_TOO_LARGE
450	+	#define HANDLER_COUNT 64
451	+
452	+	// structure to tuck away existing exception handlers
453	+	typedef struct _ExceptionPorts {
454	+	mach_msg_type_number_t maskCount;
455	+	exception_mask_t masks[HANDLER_COUNT];
456	+	exception_handler_t handlers[HANDLER_COUNT];
457	+	exception_behavior_t behaviors[HANDLER_COUNT];
458	+	thread_state_flavor_t flavors[HANDLER_COUNT];
459	+	} ExceptionPorts;
460	+
461	+	// exception handler thread
462	+	static pthread_t exc_thread;
463	+
464	+	// place where old exception handler info is stored
465	+	static ExceptionPorts ports;
466	+
467	+	// our exception port
468	+	static mach_port_t _exceptionPort = MACH_PORT_NULL;
469	+
470	+	#define MACH_CHECK_ERROR(name,ret) \
471	+	if (ret != KERN_SUCCESS) { \
472	+	mach_error(#name, ret); \
473	+	exit (1); \
474	+	}
475	+
476	+	#define SIGSEGV_FAULT_ADDRESS                   code[1]
477	+	#define SIGSEGV_FAULT_INSTRUCTION               get_fault_instruction(thread, state)
478	+	#define SIGSEGV_FAULT_HANDLER_INVOKE(ADDR, IP)  ((code[0] == KERN_PROTECTION_FAILURE) ? sigsegv_fault_handler(ADDR, IP) : SIGSEGV_RETURN_FAILURE)
479	+	#define SIGSEGV_FAULT_HANDLER_ARGLIST   mach_port_t thread, exception_data_t code, ppc_thread_state_t *state
480	+	#define SIGSEGV_FAULT_HANDLER_ARGS              thread, code, &state
481	+	#define SIGSEGV_SKIP_INSTRUCTION                powerpc_skip_instruction
482	+	#define SIGSEGV_REGISTER_FILE                   &state->srr0, &state->r0
483	+
484	+	// Given a suspended thread, stuff the current instruction and
485	+	// registers into state.
486	+	//
487	+	// It would have been nice to have this be ppc/x86 independant which
488	+	// could have been done easily with a thread_state_t instead of
489	+	// ppc_thread_state_t, but because of the way this is called it is
490	+	// easier to do it this way.
491	+	#if (defined(ppc) || defined(__ppc__))
492	+	static inline sigsegv_address_t get_fault_instruction(mach_port_t thread, ppc_thread_state_t *state)
493	+	{
494	+	kern_return_t krc;
495	+	mach_msg_type_number_t count;
496	+
497	+	count = MACHINE_THREAD_STATE_COUNT;
498	+	krc = thread_get_state(thread, MACHINE_THREAD_STATE, (thread_state_t)state, &count);
499	+	MACH_CHECK_ERROR (thread_get_state, krc);
500	+
501	+	return (sigsegv_address_t)state->srr0;
502	+	}
503	+	#endif
504	+
505	+	// Since there can only be one exception thread running at any time
506	+	// this is not a problem.
507	+	#define MSG_SIZE 512
508	+	static char msgbuf[MSG_SIZE];
509	+	static char replybuf[MSG_SIZE];
510	+
511	+	/*
512	+	* This is the entry point for the exception handler thread. The job
513	+	* of this thread is to wait for exception messages on the exception
514	+	* port that was setup beforehand and to pass them on to exc_server.
515	+	* exc_server is a MIG generated function that is a part of Mach.
516	+	* Its job is to decide what to do with the exception message. In our
517	+	* case exc_server calls catch_exception_raise on our behalf. After
518	+	* exc_server returns, it is our responsibility to send the reply.
519	+	*/
520	+	static void *
521	+	handleExceptions(void *priv)
522	+	{
523	+	mach_msg_header_t *msg, *reply;
524	+	kern_return_t krc;
525	+
526	+	msg = (mach_msg_header_t *)msgbuf;
527	+	reply = (mach_msg_header_t *)replybuf;
528	+
529	+	for (;;) {
530	+	krc = mach_msg(msg, MACH_RCV_MSG, MSG_SIZE, MSG_SIZE,
531	+	_exceptionPort, 0, MACH_PORT_NULL);
532	+	MACH_CHECK_ERROR(mach_msg, krc);
533	+
534	+	if (!exc_server(msg, reply)) {
535	+	fprintf(stderr, "exc_server hated the message\n");
536	+	exit(1);
537	+	}
538	+
539	+	krc = mach_msg(reply, MACH_SEND_MSG, reply->msgh_size, 0,
540	+	msg->msgh_local_port, 0, MACH_PORT_NULL);
541	+	if (krc != KERN_SUCCESS) {
542	+	fprintf(stderr, "Error sending message to original reply port, krc = %d, %s",
543	+	krc, mach_error_string(krc));
544	+	exit(1);
545	+	}
546	+	}
547	+	}
548	+	#endif
549	+	#endif
550	+
551	+
552	+	/*
553	+	*  Instruction skipping
554	+	*/
555	+
556	+	#ifdef HAVE_SIGSEGV_SKIP_INSTRUCTION
557	+	// Decode and skip X86 instruction
558	+	#if (defined(i386) || defined(__i386__))
559	+	#if defined(__linux__)
560	+	enum {
561	+	X86_REG_EIP = 14,
562	+	X86_REG_EAX = 11,
563	+	X86_REG_ECX = 10,
564	+	X86_REG_EDX = 9,
565	+	X86_REG_EBX = 8,
566	+	X86_REG_ESP = 7,
567	+	X86_REG_EBP = 6,
568	+	X86_REG_ESI = 5,
569	+	X86_REG_EDI = 4
570	+	};
571	+	#endif
572	+	#if defined(__NetBSD__) || defined(__FreeBSD__)
573	+	enum {
574	+	X86_REG_EIP = 10,
575	+	X86_REG_EAX = 7,
576	+	X86_REG_ECX = 6,
577	+	X86_REG_EDX = 5,
578	+	X86_REG_EBX = 4,
579	+	X86_REG_ESP = 13,
580	+	X86_REG_EBP = 2,
581	+	X86_REG_ESI = 1,
582	+	X86_REG_EDI = 0
583	+	};
584	+	#endif
585	+	// FIXME: this is partly redundant with the instruction decoding phase
586	+	// to discover transfer type and register number
587	+	static inline int ix86_step_over_modrm(unsigned char * p)
588	+	{
589	+	int mod = (p[0] >> 6) & 3;
590	+	int rm = p[0] & 7;
591	+	int offset = 0;
592	+
593	+	// ModR/M Byte
594	+	switch (mod) {
595	+	case 0: // [reg]
596	+	if (rm == 5) return 4; // disp32
597	+	break;
598	+	case 1: // disp8[reg]
599	+	offset = 1;
600	+	break;
601	+	case 2: // disp32[reg]
602	+	offset = 4;
603	+	break;
604	+	case 3: // register
605	+	return 0;
606	+	}
607	+
608	+	// SIB Byte
609	+	if (rm == 4) {
610	+	if (mod == 0 && (p[1] & 7) == 5)
611	+	offset = 5; // disp32[index]
612	+	else
613	+	offset++;
614	+	}
615	+
616	+	return offset;
617	+	}
618	+
619	+	static bool ix86_skip_instruction(unsigned int * regs)
620	+	{
621	+	unsigned char * eip = (unsigned char *)regs[X86_REG_EIP];
622	+
623	+	if (eip == 0)
624	+	return false;
625	+
626	+	transfer_type_t transfer_type = SIGSEGV_TRANSFER_UNKNOWN;
627	+	transfer_size_t transfer_size = SIZE_LONG;
628	+
629	+	int reg = -1;
630	+	int len = 0;
631	+
632	+	// Operand size prefix
633	+	if (*eip == 0x66) {
634	+	eip++;
635	+	len++;
636	+	transfer_size = SIZE_WORD;
637	+	}
638	+
639	+	// Decode instruction
640	+	switch (eip[0]) {
641	+	case 0x0f:
642	+	switch (eip[1]) {
643	+	case 0xb6: // MOVZX r32, r/m8
644	+	case 0xb7: // MOVZX r32, r/m16
645	+	switch (eip[2] & 0xc0) {
646	+	case 0x80:
647	+	reg = (eip[2] >> 3) & 7;
648	+	transfer_type = SIGSEGV_TRANSFER_LOAD;
649	+	break;
650	+	case 0x40:
651	+	reg = (eip[2] >> 3) & 7;
652	+	transfer_type = SIGSEGV_TRANSFER_LOAD;
653	+	break;
654	+	case 0x00:
655	+	reg = (eip[2] >> 3) & 7;
656	+	transfer_type = SIGSEGV_TRANSFER_LOAD;
657	+	break;
658	+	}
659	+	len += 3 + ix86_step_over_modrm(eip + 2);
660	+	break;
661	+	}
662	+	break;
663	+	case 0x8a: // MOV r8, r/m8
664	+	transfer_size = SIZE_BYTE;
665	+	case 0x8b: // MOV r32, r/m32 (or 16-bit operation)
666	+	switch (eip[1] & 0xc0) {
667	+	case 0x80:
668	+	reg = (eip[1] >> 3) & 7;
669	+	transfer_type = SIGSEGV_TRANSFER_LOAD;
670	+	break;
671	+	case 0x40:
672	+	reg = (eip[1] >> 3) & 7;
673	+	transfer_type = SIGSEGV_TRANSFER_LOAD;
674	+	break;
675	+	case 0x00:
676	+	reg = (eip[1] >> 3) & 7;
677	+	transfer_type = SIGSEGV_TRANSFER_LOAD;
678	+	break;
679	+	}
680	+	len += 2 + ix86_step_over_modrm(eip + 1);
681	+	break;
682	+	case 0x88: // MOV r/m8, r8
683	+	transfer_size = SIZE_BYTE;
684	+	case 0x89: // MOV r/m32, r32 (or 16-bit operation)
685	+	switch (eip[1] & 0xc0) {
686	+	case 0x80:
687	+	reg = (eip[1] >> 3) & 7;
688	+	transfer_type = SIGSEGV_TRANSFER_STORE;
689	+	break;
690	+	case 0x40:
691	+	reg = (eip[1] >> 3) & 7;
692	+	transfer_type = SIGSEGV_TRANSFER_STORE;
693	+	break;
694	+	case 0x00:
695	+	reg = (eip[1] >> 3) & 7;
696	+	transfer_type = SIGSEGV_TRANSFER_STORE;
697	+	break;
698	+	}
699	+	len += 2 + ix86_step_over_modrm(eip + 1);
700	+	break;
701	+	}
702	+
703	+	if (transfer_type == SIGSEGV_TRANSFER_UNKNOWN) {
704	+	// Unknown machine code, let it crash. Then patch the decoder
705	+	return false;
706	+	}
707	+
708	+	if (transfer_type == SIGSEGV_TRANSFER_LOAD && reg != -1) {
709	+	static const int x86_reg_map[8] = {
710	+	X86_REG_EAX, X86_REG_ECX, X86_REG_EDX, X86_REG_EBX,
711	+	X86_REG_ESP, X86_REG_EBP, X86_REG_ESI, X86_REG_EDI
712	+	};
713	+
714	+	if (reg < 0 || reg >= 8)
715	+	return false;
716	+
717	+	int rloc = x86_reg_map[reg];
718	+	switch (transfer_size) {
719	+	case SIZE_BYTE:
720	+	regs[rloc] = (regs[rloc] & ~0xff);
721	+	break;
722	+	case SIZE_WORD:
723	+	regs[rloc] = (regs[rloc] & ~0xffff);
724	+	break;
725	+	case SIZE_LONG:
726	+	regs[rloc] = 0;
727	+	break;
728	+	}
729	+	}
730	+
731	+	#if DEBUG
732	+	printf("%08x: %s %s access", regs[X86_REG_EIP],
733	+	transfer_size == SIZE_BYTE ? "byte" : transfer_size == SIZE_WORD ? "word" : "long",
734	+	transfer_type == SIGSEGV_TRANSFER_LOAD ? "read" : "write");
735	+
736	+	if (reg != -1) {
737	+	static const char * x86_reg_str_map[8] = {
738	+	"eax", "ecx", "edx", "ebx",
739	+	"esp", "ebp", "esi", "edi"
740	+	};
741	+	printf(" %s register %%%s", transfer_type == SIGSEGV_TRANSFER_LOAD ? "to" : "from", x86_reg_str_map[reg]);
742	+	}
743	+	printf(", %d bytes instruction\n", len);
744	+	#endif
745	+
746	+	regs[X86_REG_EIP] += len;
747	+	return true;
748	+	}
749	+	#endif
750	+
751	+	// Decode and skip PPC instruction
752	+	#if (defined(powerpc) || defined(__powerpc__) || defined(__ppc__))
753	+	static bool powerpc_skip_instruction(unsigned int * nip_p, unsigned int * regs)
754	+	{
755	+	instruction_t instr;
756	+	powerpc_decode_instruction(&instr, *nip_p, regs);
757	+
758	+	if (instr.transfer_type == SIGSEGV_TRANSFER_UNKNOWN) {
759	+	// Unknown machine code, let it crash. Then patch the decoder
760	+	return false;
761	+	}
762	+
763	+	#if DEBUG
764	+	printf("%08x: %s %s access", *nip_p,
765	+	instr.transfer_size == SIZE_BYTE ? "byte" : instr.transfer_size == SIZE_WORD ? "word" : "long",
766	+	instr.transfer_type == SIGSEGV_TRANSFER_LOAD ? "read" : "write");
767	+
768	+	if (instr.addr_mode == MODE_U || instr.addr_mode == MODE_UX)
769	+	printf(" r%d (ra = %08x)\n", instr.ra, instr.addr);
770	+	if (instr.transfer_type == SIGSEGV_TRANSFER_LOAD)
771	+	printf(" r%d (rd = 0)\n", instr.rd);
772	+	#endif
773	+
774	+	if (instr.addr_mode == MODE_U || instr.addr_mode == MODE_UX)
775	+	regs[instr.ra] = instr.addr;
776	+	if (instr.transfer_type == SIGSEGV_TRANSFER_LOAD)
777	+	regs[instr.rd] = 0;
778	+
779	+	*nip_p += 4;
780	+	return true;
781	+	}
782	+	#endif
783		#endif
784
785		// Fallbacks
786		#ifndef SIGSEGV_FAULT_INSTRUCTION
787		#define SIGSEGV_FAULT_INSTRUCTION               SIGSEGV_INVALID_PC
788		#endif
789	+	#ifndef SIGSEGV_FAULT_HANDLER_ARGLIST_1
790	+	#define SIGSEGV_FAULT_HANDLER_ARGLIST_1 SIGSEGV_FAULT_HANDLER_ARGLIST
791	+	#endif
792	+	#ifndef SIGSEGV_FAULT_HANDLER_INVOKE
793	+	#define SIGSEGV_FAULT_HANDLER_INVOKE(ADDR, IP)  sigsegv_fault_handler(ADDR, IP)
794	+	#endif
795
796		// SIGSEGV recovery supported ?
797		#if defined(SIGSEGV_ALL_SIGNALS) && defined(SIGSEGV_FAULT_HANDLER_ARGLIST) && defined(SIGSEGV_FAULT_ADDRESS)
#	Line 149 | Line 803 | static bool sigsegv_do_install_handler(i
803		*  SIGSEGV global handler
804		*/
805
806	+	#if defined(HAVE_SIGSEGV_RECOVERY) || defined(HAVE_MACH_EXCEPTIONS)
807	+	// This function handles the badaccess to memory.
808	+	// It is called from the signal handler or the exception handler.
809	+	static bool handle_badaccess(SIGSEGV_FAULT_HANDLER_ARGLIST_1)
810	+	{
811	+	sigsegv_address_t fault_address = (sigsegv_address_t)SIGSEGV_FAULT_ADDRESS;
812	+	sigsegv_address_t fault_instruction = (sigsegv_address_t)SIGSEGV_FAULT_INSTRUCTION;
813	+
814	+	// Call user's handler and reinstall the global handler, if required
815	+	switch (SIGSEGV_FAULT_HANDLER_INVOKE(fault_address, fault_instruction)) {
816	+	case SIGSEGV_RETURN_SUCCESS:
817	+	return true;
818	+
819	+	#if HAVE_SIGSEGV_SKIP_INSTRUCTION
820	+	case SIGSEGV_RETURN_SKIP_INSTRUCTION:
821	+	// Call the instruction skipper with the register file
822	+	// available
823	+	if (SIGSEGV_SKIP_INSTRUCTION(SIGSEGV_REGISTER_FILE)) {
824	+	#ifdef HAVE_MACH_EXCEPTIONS
825	+	// Unlike UNIX signals where the thread state
826	+	// is modified off of the stack, in Mach we
827	+	// need to actually call thread_set_state to
828	+	// have the register values updated.
829	+	kern_return_t krc;
830	+
831	+	krc = thread_set_state(thread,
832	+	MACHINE_THREAD_STATE, (thread_state_t)state,
833	+	MACHINE_THREAD_STATE_COUNT);
834	+	MACH_CHECK_ERROR (thread_get_state, krc);
835	+	#endif
836	+	return true;
837	+	}
838	+	break;
839	+	#endif
840	+	}
841	+
842	+	// We can't do anything with the fault_address, dump state?
843	+	if (sigsegv_state_dumper != 0)
844	+	sigsegv_state_dumper(fault_address, fault_instruction);
845	+
846	+	return false;
847	+	}
848	+	#endif
849	+
850	+
851	+	/*
852	+	* There are two mechanisms for handling a bad memory access,
853	+	* Mach exceptions and UNIX signals. The implementation specific
854	+	* code appears below. Its reponsibility is to call handle_badaccess
855	+	* which is the routine that handles the fault in an implementation
856	+	* agnostic manner. The implementation specific code below is then
857	+	* reponsible for checking whether handle_badaccess was able
858	+	* to handle the memory access error and perform any implementation
859	+	* specific tasks necessary afterwards.
860	+	*/
861	+
862	+	#ifdef HAVE_MACH_EXCEPTIONS
863	+	/*
864	+	* We need to forward all exceptions that we do not handle.
865	+	* This is important, there are many exceptions that may be
866	+	* handled by other exception handlers. For example debuggers
867	+	* use exceptions and the exception hander is in another
868	+	* process in such a case. (Timothy J. Wood states in his
869	+	* message to the list that he based this code on that from
870	+	* gdb for Darwin.)
871	+	*/
872	+	static inline kern_return_t
873	+	forward_exception(mach_port_t thread_port,
874	+	mach_port_t task_port,
875	+	exception_type_t exception_type,
876	+	exception_data_t exception_data,
877	+	mach_msg_type_number_t data_count,
878	+	ExceptionPorts *oldExceptionPorts)
879	+	{
880	+	kern_return_t kret;
881	+	unsigned int portIndex;
882	+	mach_port_t port;
883	+	exception_behavior_t behavior;
884	+	thread_state_flavor_t flavor;
885	+	thread_state_t thread_state;
886	+	mach_msg_type_number_t thread_state_count;
887	+
888	+	for (portIndex = 0; portIndex < oldExceptionPorts->maskCount; portIndex++) {
889	+	if (oldExceptionPorts->masks[portIndex] & (1 << exception_type)) {
890	+	// This handler wants the exception
891	+	break;
892	+	}
893	+	}
894	+
895	+	if (portIndex >= oldExceptionPorts->maskCount) {
896	+	fprintf(stderr, "No handler for exception_type = %d. Not fowarding\n", exception_type);
897	+	return KERN_FAILURE;
898	+	}
899	+
900	+	port = oldExceptionPorts->handlers[portIndex];
901	+	behavior = oldExceptionPorts->behaviors[portIndex];
902	+	flavor = oldExceptionPorts->flavors[portIndex];
903	+
904	+	/*
905	+	fprintf(stderr, "forwarding exception, port = 0x%x, behaviour = %d, flavor = %d\n", port, behavior, flavor);
906	+	*/
907	+
908	+	if (behavior != EXCEPTION_DEFAULT) {
909	+	thread_state_count = THREAD_STATE_MAX;
910	+	kret = thread_get_state (thread_port, flavor, thread_state,
911	+	&thread_state_count);
912	+	MACH_CHECK_ERROR (thread_get_state, kret);
913	+	}
914	+
915	+	switch (behavior) {
916	+	case EXCEPTION_DEFAULT:
917	+	// fprintf(stderr, "forwarding to exception_raise\n");
918	+	kret = exception_raise(port, thread_port, task_port, exception_type,
919	+	exception_data, data_count);
920	+	MACH_CHECK_ERROR (exception_raise, kret);
921	+	break;
922	+	case EXCEPTION_STATE:
923	+	// fprintf(stderr, "forwarding to exception_raise_state\n");
924	+	kret = exception_raise_state(port, exception_type, exception_data,
925	+	data_count, &flavor,
926	+	thread_state, thread_state_count,
927	+	thread_state, &thread_state_count);
928	+	MACH_CHECK_ERROR (exception_raise_state, kret);
929	+	break;
930	+	case EXCEPTION_STATE_IDENTITY:
931	+	// fprintf(stderr, "forwarding to exception_raise_state_identity\n");
932	+	kret = exception_raise_state_identity(port, thread_port, task_port,
933	+	exception_type, exception_data,
934	+	data_count, &flavor,
935	+	thread_state, thread_state_count,
936	+	thread_state, &thread_state_count);
937	+	MACH_CHECK_ERROR (exception_raise_state_identity, kret);
938	+	break;
939	+	default:
940	+	fprintf(stderr, "forward_exception got unknown behavior\n");
941	+	break;
942	+	}
943	+
944	+	if (behavior != EXCEPTION_DEFAULT) {
945	+	kret = thread_set_state (thread_port, flavor, thread_state,
946	+	thread_state_count);
947	+	MACH_CHECK_ERROR (thread_set_state, kret);
948	+	}
949	+
950	+	return KERN_SUCCESS;
951	+	}
952	+
953	+	/*
954	+	* This is the code that actually handles the exception.
955	+	* It is called by exc_server. For Darwin 5 Apple changed
956	+	* this a bit from how this family of functions worked in
957	+	* Mach. If you are familiar with that it is a little
958	+	* different. The main variation that concerns us here is
959	+	* that code is an array of exception specific codes and
960	+	* codeCount is a count of the number of codes in the code
961	+	* array. In typical Mach all exceptions have a code
962	+	* and sub-code. It happens to be the case that for a
963	+	* EXC_BAD_ACCESS exception the first entry is the type of
964	+	* bad access that occurred and the second entry is the
965	+	* faulting address so these entries correspond exactly to
966	+	* how the code and sub-code are used on Mach.
967	+	*
968	+	* This is a MIG interface. No code in Basilisk II should
969	+	* call this directley. This has to have external C
970	+	* linkage because that is what exc_server expects.
971	+	*/
972	+	kern_return_t
973	+	catch_exception_raise(mach_port_t exception_port,
974	+	mach_port_t thread,
975	+	mach_port_t task,
976	+	exception_type_t exception,
977	+	exception_data_t code,
978	+	mach_msg_type_number_t codeCount)
979	+	{
980	+	ppc_thread_state_t state;
981	+	kern_return_t krc;
982	+
983	+	if ((exception == EXC_BAD_ACCESS)  && (codeCount >= 2)) {
984	+	if (handle_badaccess(SIGSEGV_FAULT_HANDLER_ARGS))
985	+	return KERN_SUCCESS;
986	+	}
987	+
988	+	// In Mach we do not need to remove the exception handler.
989	+	// If we forward the exception, eventually some exception handler
990	+	// will take care of this exception.
991	+	krc = forward_exception(thread, task, exception, code, codeCount, &ports);
992	+
993	+	return krc;
994	+	}
995	+	#endif
996	+
997		#ifdef HAVE_SIGSEGV_RECOVERY
998	+	// Handle bad memory accesses with signal handler
999		static void sigsegv_handler(SIGSEGV_FAULT_HANDLER_ARGLIST)
1000		{
1001	<	// Call user's handler and reinstall the global handler, if required
1002	<	if (sigsegv_user_handler((sigsegv_address_t)SIGSEGV_FAULT_ADDRESS, (sigsegv_address_t)SIGSEGV_FAULT_INSTRUCTION)) {
1001	>	// Call handler and reinstall the global handler, if required
1002	>	if (handle_badaccess(SIGSEGV_FAULT_HANDLER_ARGS)) {
1003		#if (defined(HAVE_SIGACTION) ? defined(SIGACTION_NEED_REINSTALL) : defined(SIGNAL_NEED_REINSTALL))
1004		sigsegv_do_install_handler(sig);
1005		#endif
1006	+	return;
1007		}
1008	<	else {
1009	<	// FAIL: reinstall default handler for "safe" crash
1008	>
1009	>	// Failure: reinstall default handler for "safe" crash
1010		#define FAULT_HANDLER(sig) signal(sig, SIG_DFL);
1011	<	SIGSEGV_ALL_SIGNALS
1011	>	SIGSEGV_ALL_SIGNALS
1012		#undef FAULT_HANDLER
166	–	}
1013		}
1014		#endif
1015
#	Line 177 | Line 1023 | static bool sigsegv_do_install_handler(i
1023		{
1024		// Setup SIGSEGV handler to process writes to frame buffer
1025		#ifdef HAVE_SIGACTION
1026	<	struct sigaction vosf_sa;
1027	<	sigemptyset(&vosf_sa.sa_mask);
1028	<	vosf_sa.sa_sigaction = sigsegv_handler;
1029	<	vosf_sa.sa_flags = SA_SIGINFO;
1030	<	return (sigaction(sig, &vosf_sa, 0) == 0);
1026	>	struct sigaction sigsegv_sa;
1027	>	sigemptyset(&sigsegv_sa.sa_mask);
1028	>	sigsegv_sa.sa_sigaction = sigsegv_handler;
1029	>	sigsegv_sa.sa_flags = SA_SIGINFO;
1030	>	return (sigaction(sig, &sigsegv_sa, 0) == 0);
1031		#else
1032		return (signal(sig, (signal_handler)sigsegv_handler) != SIG_ERR);
1033		#endif
#	Line 193 | Line 1039 | static bool sigsegv_do_install_handler(i
1039		{
1040		// Setup SIGSEGV handler to process writes to frame buffer
1041		#ifdef HAVE_SIGACTION
1042	<	struct sigaction vosf_sa;
1043	<	sigemptyset(&vosf_sa.sa_mask);
1044	<	vosf_sa.sa_handler = (signal_handler)sigsegv_handler;
1042	>	struct sigaction sigsegv_sa;
1043	>	sigemptyset(&sigsegv_sa.sa_mask);
1044	>	sigsegv_sa.sa_handler = (signal_handler)sigsegv_handler;
1045	>	sigsegv_sa.sa_flags = 0;
1046		#if !EMULATED_68K && defined(__NetBSD__)
1047	<	sigaddset(&vosf_sa.sa_mask, SIGALRM);
1048	<	vosf_sa.sa_flags = SA_ONSTACK;
202	<	#else
203	<	vosf_sa.sa_flags = 0;
1047	>	sigaddset(&sigsegv_sa.sa_mask, SIGALRM);
1048	>	sigsegv_sa.sa_flags |= SA_ONSTACK;
1049		#endif
1050	<	return (sigaction(sig, &vosf_sa, 0) == 0);
1050	>	return (sigaction(sig, &sigsegv_sa, 0) == 0);
1051		#else
1052		return (signal(sig, (signal_handler)sigsegv_handler) != SIG_ERR);
1053		#endif
1054		}
1055		#endif
1056
1057	<	bool sigsegv_install_handler(sigsegv_handler_t handler)
1057	>	#if defined(HAVE_MACH_EXCEPTIONS)
1058	>	static bool sigsegv_do_install_handler(sigsegv_fault_handler_t handler)
1059		{
1060	<	#ifdef HAVE_SIGSEGV_RECOVERY
1061	<	sigsegv_user_handler = handler;
1060	>	/*
1061	>	* Except for the exception port functions, this should be
1062	>	* pretty much stock Mach. If later you choose to support
1063	>	* other Mach's besides Darwin, just check for __MACH__
1064	>	* here and __APPLE__ where the actual differences are.
1065	>	*/
1066	>	#if defined(__APPLE__) && defined(__MACH__)
1067	>	if (sigsegv_fault_handler != NULL) {
1068	>	sigsegv_fault_handler = handler;
1069	>	return true;
1070	>	}
1071	>
1072	>	kern_return_t krc;
1073	>
1074	>	// create the the exception port
1075	>	krc = mach_port_allocate(mach_task_self(),
1076	>	MACH_PORT_RIGHT_RECEIVE, &_exceptionPort);
1077	>	if (krc != KERN_SUCCESS) {
1078	>	mach_error("mach_port_allocate", krc);
1079	>	return false;
1080	>	}
1081	>
1082	>	// add a port send right
1083	>	krc = mach_port_insert_right(mach_task_self(),
1084	>	_exceptionPort, _exceptionPort,
1085	>	MACH_MSG_TYPE_MAKE_SEND);
1086	>	if (krc != KERN_SUCCESS) {
1087	>	mach_error("mach_port_insert_right", krc);
1088	>	return false;
1089	>	}
1090	>
1091	>	// get the old exception ports
1092	>	ports.maskCount = sizeof (ports.masks) / sizeof (ports.masks[0]);
1093	>	krc = thread_get_exception_ports(mach_thread_self(), EXC_MASK_BAD_ACCESS, ports.masks,
1094	>	&ports.maskCount, ports.handlers, ports.behaviors, ports.flavors);
1095	>	if (krc != KERN_SUCCESS) {
1096	>	mach_error("thread_get_exception_ports", krc);
1097	>	return false;
1098	>	}
1099	>
1100	>	// set the new exception port
1101	>	//
1102	>	// We could have used EXCEPTION_STATE_IDENTITY instead of
1103	>	// EXCEPTION_DEFAULT to get the thread state in the initial
1104	>	// message, but it turns out that in the common case this is not
1105	>	// neccessary. If we need it we can later ask for it from the
1106	>	// suspended thread.
1107	>	//
1108	>	// Even with THREAD_STATE_NONE, Darwin provides the program
1109	>	// counter in the thread state.  The comments in the header file
1110	>	// seem to imply that you can count on the GPR's on an exception
1111	>	// as well but just to be safe I use MACHINE_THREAD_STATE because
1112	>	// you have to ask for all of the GPR's anyway just to get the
1113	>	// program counter. In any case because of update effective
1114	>	// address from immediate and update address from effective
1115	>	// addresses of ra and rb modes (as good an name as any for these
1116	>	// addressing modes) used in PPC instructions, you will need the
1117	>	// GPR state anyway.
1118	>	krc = thread_set_exception_ports(mach_thread_self(), EXC_MASK_BAD_ACCESS, _exceptionPort,
1119	>	EXCEPTION_DEFAULT, MACHINE_THREAD_STATE);
1120	>	if (krc != KERN_SUCCESS) {
1121	>	mach_error("thread_set_exception_ports", krc);
1122	>	return false;
1123	>	}
1124	>
1125	>	// create the exception handler thread
1126	>	if (pthread_create(&exc_thread, NULL, &handleExceptions, NULL) != 0) {
1127	>	(void)fprintf(stderr, "creation of exception thread failed\n");
1128	>	return false;
1129	>	}
1130	>
1131	>	// do not care about the exception thread any longer, let is run standalone
1132	>	(void)pthread_detach(exc_thread);
1133	>
1134	>	sigsegv_fault_handler = handler;
1135	>	return true;
1136	>	#else
1137	>	return false;
1138	>	#endif
1139	>	}
1140	>	#endif
1141	>
1142	>	bool sigsegv_install_handler(sigsegv_fault_handler_t handler)
1143	>	{
1144	>	#if defined(HAVE_SIGSEGV_RECOVERY)
1145		bool success = true;
1146		#define FAULT_HANDLER(sig) success = success && sigsegv_do_install_handler(sig);
1147		SIGSEGV_ALL_SIGNALS
1148		#undef FAULT_HANDLER
1149	+	if (success)
1150	+	sigsegv_fault_handler = handler;
1151		return success;
1152	+	#elif defined(HAVE_MACH_EXCEPTIONS)
1153	+	return sigsegv_do_install_handler(handler);
1154		#else
1155		// FAIL: no siginfo_t nor sigcontext subterfuge is available
1156		return false;
#	Line 231 | Line 1164 | bool sigsegv_install_handler(sigsegv_han
1164
1165		void sigsegv_deinstall_handler(void)
1166		{
1167	+	// We do nothing for Mach exceptions, the thread would need to be
1168	+	// suspended if not already so, and we might mess with other
1169	+	// exception handlers that came after we registered ours. There is
1170	+	// no need to remove the exception handler, in fact this function is
1171	+	// not called anywhere in Basilisk II.
1172		#ifdef HAVE_SIGSEGV_RECOVERY
1173	<	sigsegv_user_handler = 0;
1173	>	sigsegv_fault_handler = 0;
1174		#define FAULT_HANDLER(sig) signal(sig, SIG_DFL);
1175		SIGSEGV_ALL_SIGNALS
1176		#undef FAULT_HANDLER
1177		#endif
1178		}
1179
1180	+
1181	+	/*
1182	+	*  Set callback function when we cannot handle the fault
1183	+	*/
1184	+
1185	+	void sigsegv_set_dump_state(sigsegv_state_dumper_t handler)
1186	+	{
1187	+	sigsegv_state_dumper = handler;
1188	+	}
1189	+
1190	+
1191		/*
1192		*  Test program used for configure/test
1193		*/
1194
1195	<	#ifdef CONFIGURE_TEST
1195	>	#ifdef CONFIGURE_TEST_SIGSEGV_RECOVERY
1196		#include <stdio.h>
1197		#include <stdlib.h>
249	–	#include <unistd.h>
1198		#include <fcntl.h>
1199		#include <sys/mman.h>
1200	+	#include "vm_alloc.h"
1201	+
1202	+	const int REF_INDEX = 123;
1203	+	const int REF_VALUE = 45;
1204
1205		static int page_size;
1206		static volatile char * page = 0;
1207		static volatile int handler_called = 0;
1208
1209	<	static bool sigsegv_test_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_test_handler(sigsegv_address_t fault_address, sigsegv_address_t instruction_address)
1215		{
1216		handler_called++;
1217	<	if ((fault_address - 123) != page)
1218	<	exit(1);
1219	<	if (mprotect((char *)((unsigned long)fault_address & -page_size), page_size, PROT_READ | PROT_WRITE) != 0)
1220	<	exit(1);
1221	<	return true;
1217	>	if ((fault_address - REF_INDEX) != page)
1218	>	exit(10);
1219	>	#ifdef __GNUC__
1220	>	// Make sure reported fault instruction address falls into
1221	>	// expected code range
1222	>	if (instruction_address != SIGSEGV_INVALID_PC
1223	>	&& ((instruction_address <  (sigsegv_address_t)b_region) ||
1224	>	(instruction_address >= (sigsegv_address_t)e_region)))
1225	>	exit(11);
1226	>	#endif
1227	>	if (vm_protect((char *)((unsigned long)fault_address & -page_size), page_size, VM_PAGE_READ | VM_PAGE_WRITE) != 0)
1228	>	exit(12);
1229	>	return SIGSEGV_RETURN_SUCCESS;
1230		}
1231
1232	+	#ifdef HAVE_SIGSEGV_SKIP_INSTRUCTION
1233	+	static sigsegv_return_t sigsegv_insn_handler(sigsegv_address_t fault_address, sigsegv_address_t instruction_address)
1234	+	{
1235	+	if (((unsigned long)fault_address - (unsigned long)page) < page_size) {
1236	+	#ifdef __GNUC__
1237	+	// Make sure reported fault instruction address falls into
1238	+	// expected code range
1239	+	if (instruction_address != SIGSEGV_INVALID_PC
1240	+	&& ((instruction_address <  (sigsegv_address_t)b_region) ||
1241	+	(instruction_address >= (sigsegv_address_t)e_region)))
1242	+	return SIGSEGV_RETURN_FAILURE;
1243	+	#endif
1244	+	return SIGSEGV_RETURN_SKIP_INSTRUCTION;
1245	+	}
1246	+
1247	+	return SIGSEGV_RETURN_FAILURE;
1248	+	}
1249	+	#endif
1250	+
1251		int main(void)
1252		{
1253	<	int zero_fd = open("/dev/zero", O_RDWR);
270	<	if (zero_fd < 0)
1253	>	if (vm_init() < 0)
1254		return 1;
1255
1256		page_size = getpagesize();
1257	<	page = (char *)mmap(0, page_size, PROT_READ, MAP_PRIVATE, zero_fd, 0);
1258	<	if (page == MAP_FAILED)
276	<	return 1;
1257	>	if ((page = (char *)vm_acquire(page_size)) == VM_MAP_FAILED)
1258	>	return 2;
1259
1260	<	if (!sigsegv_install_handler(sigsegv_test_handler))
1261	<	return 1;
1260	>	memset((void *)page, 0, page_size);
1261	>	if (vm_protect((char *)page, page_size, VM_PAGE_READ) < 0)
1262	>	return 3;
1263
1264	<	page[123] = 45;
1265	<	page[123] = 45;
1264	>	if (!sigsegv_install_handler(sigsegv_test_handler))
1265	>	return 4;
1266
1267	+	#ifdef __GNUC__
1268	+	b_region = &&L_b_region1;
1269	+	e_region = &&L_e_region1;
1270	+	#endif
1271	+	L_b_region1:
1272	+	page[REF_INDEX] = REF_VALUE;
1273	+	if (page[REF_INDEX] != REF_VALUE)
1274	+	exit(20);
1275	+	page[REF_INDEX] = REF_VALUE;
1276	+	L_e_region1:
1277	+
1278		if (handler_called != 1)
1279	<	return 1;
1279	>	return 5;
1280	>
1281	>	#ifdef HAVE_SIGSEGV_SKIP_INSTRUCTION
1282	>	if (!sigsegv_install_handler(sigsegv_insn_handler))
1283	>	return 6;
1284	>
1285	>	if (vm_protect((char *)page, page_size, VM_PAGE_READ | VM_PAGE_WRITE) < 0)
1286	>	return 7;
1287	>
1288	>	for (int i = 0; i < page_size; i++)
1289	>	page[i] = (i + 1) % page_size;
1290	>
1291	>	if (vm_protect((char *)page, page_size, VM_PAGE_NOACCESS) < 0)
1292	>	return 8;
1293	>
1294	>	#define TEST_SKIP_INSTRUCTION(TYPE) do {                                \
1295	>	const unsigned int TAG = 0x12345678;                    \
1296	>	TYPE data = *((TYPE *)(page + sizeof(TYPE)));   \
1297	>	volatile unsigned int effect = data + TAG;              \
1298	>	if (effect != TAG)                                                              \
1299	>	return 9;                                                                       \
1300	>	} while (0)
1301	>
1302	>	#ifdef __GNUC__
1303	>	b_region = &&L_b_region2;
1304	>	e_region = &&L_e_region2;
1305	>	#endif
1306	>	L_b_region2:
1307	>	TEST_SKIP_INSTRUCTION(unsigned char);
1308	>	TEST_SKIP_INSTRUCTION(unsigned short);
1309	>	TEST_SKIP_INSTRUCTION(unsigned int);
1310	>	L_e_region2:
1311	>	#endif
1312
1313	+	vm_exit();
1314		return 0;
1315		}
1316		#endif
1317	+
1318	+
1319	+
1320	+
1321	+
1322	+
1323	+
1324	+
1325	+
1326	+
1327	+
1328	+
1329	+
1330	+
1331	+

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