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

Comparing BasiliskII/src/Unix/sigsegv.cpp (file contents):
Revision 1.2 by gbeauche, 2001-05-21T03:21:54Z vs.
Revision 1.33 by gbeauche, 2003-10-21T23:10:19Z

#	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(__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		#endif
301		#endif
302
303		// Irix 5 or 6 on MIPS
304		#if (defined(sgi) || defined(__sgi)) && (defined(SYSTYPE_SVR4) || defined(__SYSTYPE_SVR4))
305	+	#include <ucontext.h>
306		#define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, int code, struct sigcontext *scp
307	+	#define SIGSEGV_FAULT_HANDLER_ARGS              sig, code, scp
308		#define SIGSEGV_FAULT_ADDRESS                   scp->sc_badvaddr
309		#define SIGSEGV_ALL_SIGNALS                             FAULT_HANDLER(SIGSEGV)
310		#endif
311
312	+	// HP-UX
313	+	#if (defined(hpux) || defined(__hpux__))
314	+	#define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, int code, struct sigcontext *scp
315	+	#define SIGSEGV_FAULT_HANDLER_ARGS              sig, code, scp
316	+	#define SIGSEGV_FAULT_ADDRESS                   scp->sc_sl.sl_ss.ss_narrow.ss_cr21
317	+	#define SIGSEGV_ALL_SIGNALS                             FAULT_HANDLER(SIGSEGV) FAULT_HANDLER(SIGBUS)
318	+	#endif
319	+
320		// OSF/1 on Alpha
321		#if defined(__osf__)
322	+	#include <ucontext.h>
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_traparg_a0
326		#define SIGSEGV_ALL_SIGNALS                             FAULT_HANDLER(SIGSEGV)
327		#endif
#	Line 98 | Line 329 | static bool sigsegv_do_install_handler(i
329		// AIX
330		#if defined(_AIX)
331		#define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, int code, struct sigcontext *scp
332	+	#define SIGSEGV_FAULT_HANDLER_ARGS              sig, code, scp
333		#define SIGSEGV_FAULT_ADDRESS                   scp->sc_jmpbuf.jmp_context.o_vaddr
334		#define SIGSEGV_ALL_SIGNALS                             FAULT_HANDLER(SIGSEGV)
335		#endif
336
337	<	// NetBSD or FreeBSD
338	<	#if defined(__NetBSD__) || defined(__FreeBSD__)
337	>	// NetBSD
338	>	#if defined(__NetBSD__)
339		#if (defined(m68k) || defined(__m68k__))
340		#include <m68k/frame.h>
341		#define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, int code, struct sigcontext *scp
342	<	#define SIGSEGV_FAULT_ADDRESS                   ({                                                                                                                              \
343	<	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	<	})
342	>	#define SIGSEGV_FAULT_HANDLER_ARGS              sig, code, scp
343	>	#define SIGSEGV_FAULT_ADDRESS                   get_fault_address(scp)
344		#define SIGSEGV_ALL_SIGNALS                             FAULT_HANDLER(SIGSEGV)
345	<	#else
346	<	#define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, int code, void *scp, char *addr
345	>
346	>	// Use decoding scheme from BasiliskII/m68k native
347	>	static sigsegv_address_t get_fault_address(struct sigcontext *scp)
348	>	{
349	>	struct sigstate {
350	>	int ss_flags;
351	>	struct frame ss_frame;
352	>	};
353	>	struct sigstate *state = (struct sigstate *)scp->sc_ap;
354	>	char *fault_addr;
355	>	switch (state->ss_frame.f_format) {
356	>	case 7:         /* 68040 access error */
357	>	/* "code" is sometimes unreliable (i.e. contains NULL or a bogus address), reason unknown */
358	>	fault_addr = state->ss_frame.f_fmt7.f_fa;
359	>	break;
360	>	default:
361	>	fault_addr = (char *)code;
362	>	break;
363	>	}
364	>	return (sigsegv_address_t)fault_addr;
365	>	}
366	>	#endif
367	>	#if (defined(alpha) || defined(__alpha__))
368	>	#define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, int code, struct sigcontext *scp
369	>	#define SIGSEGV_FAULT_HANDLER_ARGS              sig, code, scp
370	>	#define SIGSEGV_FAULT_ADDRESS                   get_fault_address(scp)
371	>	#define SIGSEGV_ALL_SIGNALS                             FAULT_HANDLER(SIGBUS)
372	>	#endif
373	>	#if (defined(i386) || defined(__i386__))
374	>	#error "FIXME: need to decode instruction and compute EA"
375	>	#define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, int code, struct sigcontext *scp
376	>	#define SIGSEGV_FAULT_HANDLER_ARGS              sig, code, scp
377	>	#define SIGSEGV_ALL_SIGNALS                             FAULT_HANDLER(SIGSEGV)
378	>	#endif
379	>	#endif
380	>	#if defined(__FreeBSD__)
381	>	#define SIGSEGV_ALL_SIGNALS                             FAULT_HANDLER(SIGBUS)
382	>	#if (defined(i386) || defined(__i386__))
383	>	#define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, int code, struct sigcontext *scp, char *addr
384	>	#define SIGSEGV_FAULT_HANDLER_ARGS              sig, code, scp, addr
385		#define SIGSEGV_FAULT_ADDRESS                   addr
386	+	#define SIGSEGV_FAULT_INSTRUCTION               scp->sc_eip
387	+	#define SIGSEGV_REGISTER_FILE                   ((unsigned int *)&scp->sc_edi)
388	+	#define SIGSEGV_SKIP_INSTRUCTION                ix86_skip_instruction
389	+	#endif
390	+	#endif
391	+
392	+	// Extract fault address out of a sigcontext
393	+	#if (defined(alpha) || defined(__alpha__))
394	+	// From Boehm's GC 6.0alpha8
395	+	static sigsegv_address_t get_fault_address(struct sigcontext *scp)
396	+	{
397	+	unsigned int instruction = *((unsigned int *)(scp->sc_pc));
398	+	unsigned long fault_address = scp->sc_regs[(instruction >> 16) & 0x1f];
399	+	fault_address += (signed long)(signed short)(instruction & 0xffff);
400	+	return (sigsegv_address_t)fault_address;
401	+	}
402	+	#endif
403	+
404	+
405	+	// MacOS X, not sure which version this works in. Under 10.1
406	+	// vm_protect does not appear to work from a signal handler. Under
407	+	// 10.2 signal handlers get siginfo type arguments but the si_addr
408	+	// field is the address of the faulting instruction and not the
409	+	// address that caused the SIGBUS. Maybe this works in 10.0? In any
410	+	// case with Mach exception handlers there is a way to do what this
411	+	// was meant to do.
412	+	#ifndef HAVE_MACH_EXCEPTIONS
413	+	#if defined(__APPLE__) && defined(__MACH__)
414	+	#if (defined(ppc) || defined(__ppc__))
415	+	#define SIGSEGV_FAULT_HANDLER_ARGLIST   int sig, int code, struct sigcontext *scp
416	+	#define SIGSEGV_FAULT_HANDLER_ARGS              sig, code, scp
417	+	#define SIGSEGV_FAULT_ADDRESS                   get_fault_address(scp)
418	+	#define SIGSEGV_FAULT_INSTRUCTION               scp->sc_ir
419		#define SIGSEGV_ALL_SIGNALS                             FAULT_HANDLER(SIGBUS)
420	+	#define SIGSEGV_REGISTER_FILE                   (unsigned int *)&scp->sc_ir, &((unsigned int *) scp->sc_regs)[2]
421	+	#define SIGSEGV_SKIP_INSTRUCTION                powerpc_skip_instruction
422	+
423	+	// Use decoding scheme from SheepShaver
424	+	static sigsegv_address_t get_fault_address(struct sigcontext *scp)
425	+	{
426	+	unsigned int   nip = (unsigned int) scp->sc_ir;
427	+	unsigned int * gpr = &((unsigned int *) scp->sc_regs)[2];
428	+	instruction_t  instr;
429	+
430	+	powerpc_decode_instruction(&instr, nip, gpr);
431	+	return (sigsegv_address_t)instr.addr;
432	+	}
433	+	#endif
434	+	#endif
435	+	#endif
436	+	#endif
437	+
438	+	#if HAVE_MACH_EXCEPTIONS
439	+
440	+	// This can easily be extended to other Mach systems, but really who
441	+	// uses HURD (oops GNU/HURD), Darwin/x86, NextStep, Rhapsody, or CMU
442	+	// Mach 2.5/3.0?
443	+	#if defined(__APPLE__) && defined(__MACH__)
444	+
445	+	#include <sys/types.h>
446	+	#include <stdlib.h>
447	+	#include <stdio.h>
448	+	#include <pthread.h>
449	+
450	+	/*
451	+	* If you are familiar with MIG then you will understand the frustration
452	+	* that was necessary to get these embedded into C++ code by hand.
453	+	*/
454	+	extern "C" {
455	+	#include <mach/mach.h>
456	+	#include <mach/mach_error.h>
457	+
458	+	extern boolean_t exc_server(mach_msg_header_t *, mach_msg_header_t *);
459	+	extern kern_return_t catch_exception_raise(mach_port_t, mach_port_t,
460	+	mach_port_t, exception_type_t, exception_data_t, mach_msg_type_number_t);
461	+	extern kern_return_t exception_raise(mach_port_t, mach_port_t, mach_port_t,
462	+	exception_type_t, exception_data_t, mach_msg_type_number_t);
463	+	extern kern_return_t exception_raise_state(mach_port_t, exception_type_t,
464	+	exception_data_t, mach_msg_type_number_t, thread_state_flavor_t *,
465	+	thread_state_t, mach_msg_type_number_t, thread_state_t, mach_msg_type_number_t *);
466	+	extern kern_return_t exception_raise_state_identity(mach_port_t, mach_port_t, mach_port_t,
467	+	exception_type_t, exception_data_t, mach_msg_type_number_t, thread_state_flavor_t *,
468	+	thread_state_t, mach_msg_type_number_t, thread_state_t, mach_msg_type_number_t *);
469	+	}
470	+
471	+	// Could make this dynamic by looking for a result of MIG_ARRAY_TOO_LARGE
472	+	#define HANDLER_COUNT 64
473	+
474	+	// structure to tuck away existing exception handlers
475	+	typedef struct _ExceptionPorts {
476	+	mach_msg_type_number_t maskCount;
477	+	exception_mask_t masks[HANDLER_COUNT];
478	+	exception_handler_t handlers[HANDLER_COUNT];
479	+	exception_behavior_t behaviors[HANDLER_COUNT];
480	+	thread_state_flavor_t flavors[HANDLER_COUNT];
481	+	} ExceptionPorts;
482	+
483	+	// exception handler thread
484	+	static pthread_t exc_thread;
485	+
486	+	// place where old exception handler info is stored
487	+	static ExceptionPorts ports;
488	+
489	+	// our exception port
490	+	static mach_port_t _exceptionPort = MACH_PORT_NULL;
491	+
492	+	#define MACH_CHECK_ERROR(name,ret) \
493	+	if (ret != KERN_SUCCESS) { \
494	+	mach_error(#name, ret); \
495	+	exit (1); \
496	+	}
497	+
498	+	#define SIGSEGV_FAULT_ADDRESS                   code[1]
499	+	#define SIGSEGV_FAULT_INSTRUCTION               get_fault_instruction(thread, state)
500	+	#define SIGSEGV_FAULT_HANDLER_INVOKE(ADDR, IP)  ((code[0] == KERN_PROTECTION_FAILURE) ? sigsegv_fault_handler(ADDR, IP) : SIGSEGV_RETURN_FAILURE)
501	+	#define SIGSEGV_FAULT_HANDLER_ARGLIST   mach_port_t thread, exception_data_t code, ppc_thread_state_t *state
502	+	#define SIGSEGV_FAULT_HANDLER_ARGS              thread, code, &state
503	+	#define SIGSEGV_SKIP_INSTRUCTION                powerpc_skip_instruction
504	+	#define SIGSEGV_REGISTER_FILE                   &state->srr0, &state->r0
505	+
506	+	// Given a suspended thread, stuff the current instruction and
507	+	// registers into state.
508	+	//
509	+	// It would have been nice to have this be ppc/x86 independant which
510	+	// could have been done easily with a thread_state_t instead of
511	+	// ppc_thread_state_t, but because of the way this is called it is
512	+	// easier to do it this way.
513	+	#if (defined(ppc) || defined(__ppc__))
514	+	static inline sigsegv_address_t get_fault_instruction(mach_port_t thread, ppc_thread_state_t *state)
515	+	{
516	+	kern_return_t krc;
517	+	mach_msg_type_number_t count;
518	+
519	+	count = MACHINE_THREAD_STATE_COUNT;
520	+	krc = thread_get_state(thread, MACHINE_THREAD_STATE, (thread_state_t)state, &count);
521	+	MACH_CHECK_ERROR (thread_get_state, krc);
522	+
523	+	return (sigsegv_address_t)state->srr0;
524	+	}
525	+	#endif
526	+
527	+	// Since there can only be one exception thread running at any time
528	+	// this is not a problem.
529	+	#define MSG_SIZE 512
530	+	static char msgbuf[MSG_SIZE];
531	+	static char replybuf[MSG_SIZE];
532	+
533	+	/*
534	+	* This is the entry point for the exception handler thread. The job
535	+	* of this thread is to wait for exception messages on the exception
536	+	* port that was setup beforehand and to pass them on to exc_server.
537	+	* exc_server is a MIG generated function that is a part of Mach.
538	+	* Its job is to decide what to do with the exception message. In our
539	+	* case exc_server calls catch_exception_raise on our behalf. After
540	+	* exc_server returns, it is our responsibility to send the reply.
541	+	*/
542	+	static void *
543	+	handleExceptions(void *priv)
544	+	{
545	+	mach_msg_header_t *msg, *reply;
546	+	kern_return_t krc;
547	+
548	+	msg = (mach_msg_header_t *)msgbuf;
549	+	reply = (mach_msg_header_t *)replybuf;
550	+
551	+	for (;;) {
552	+	krc = mach_msg(msg, MACH_RCV_MSG, MSG_SIZE, MSG_SIZE,
553	+	_exceptionPort, 0, MACH_PORT_NULL);
554	+	MACH_CHECK_ERROR(mach_msg, krc);
555	+
556	+	if (!exc_server(msg, reply)) {
557	+	fprintf(stderr, "exc_server hated the message\n");
558	+	exit(1);
559	+	}
560	+
561	+	krc = mach_msg(reply, MACH_SEND_MSG, reply->msgh_size, 0,
562	+	msg->msgh_local_port, 0, MACH_PORT_NULL);
563	+	if (krc != KERN_SUCCESS) {
564	+	fprintf(stderr, "Error sending message to original reply port, krc = %d, %s",
565	+	krc, mach_error_string(krc));
566	+	exit(1);
567	+	}
568	+	}
569	+	}
570	+	#endif
571	+	#endif
572	+
573	+
574	+	/*
575	+	*  Instruction skipping
576	+	*/
577	+
578	+	#ifdef HAVE_SIGSEGV_SKIP_INSTRUCTION
579	+	// Decode and skip X86 instruction
580	+	#if (defined(i386) || defined(__i386__))
581	+	#if defined(__linux__)
582	+	enum {
583	+	X86_REG_EIP = 14,
584	+	X86_REG_EAX = 11,
585	+	X86_REG_ECX = 10,
586	+	X86_REG_EDX = 9,
587	+	X86_REG_EBX = 8,
588	+	X86_REG_ESP = 7,
589	+	X86_REG_EBP = 6,
590	+	X86_REG_ESI = 5,
591	+	X86_REG_EDI = 4
592	+	};
593	+	#endif
594	+	#if defined(__NetBSD__) || defined(__FreeBSD__)
595	+	enum {
596	+	X86_REG_EIP = 10,
597	+	X86_REG_EAX = 7,
598	+	X86_REG_ECX = 6,
599	+	X86_REG_EDX = 5,
600	+	X86_REG_EBX = 4,
601	+	X86_REG_ESP = 13,
602	+	X86_REG_EBP = 2,
603	+	X86_REG_ESI = 1,
604	+	X86_REG_EDI = 0
605	+	};
606	+	#endif
607	+	// FIXME: this is partly redundant with the instruction decoding phase
608	+	// to discover transfer type and register number
609	+	static inline int ix86_step_over_modrm(unsigned char * p)
610	+	{
611	+	int mod = (p[0] >> 6) & 3;
612	+	int rm = p[0] & 7;
613	+	int offset = 0;
614	+
615	+	// ModR/M Byte
616	+	switch (mod) {
617	+	case 0: // [reg]
618	+	if (rm == 5) return 4; // disp32
619	+	break;
620	+	case 1: // disp8[reg]
621	+	offset = 1;
622	+	break;
623	+	case 2: // disp32[reg]
624	+	offset = 4;
625	+	break;
626	+	case 3: // register
627	+	return 0;
628	+	}
629	+
630	+	// SIB Byte
631	+	if (rm == 4) {
632	+	if (mod == 0 && (p[1] & 7) == 5)
633	+	offset = 5; // disp32[index]
634	+	else
635	+	offset++;
636	+	}
637	+
638	+	return offset;
639	+	}
640	+
641	+	static bool ix86_skip_instruction(unsigned int * regs)
642	+	{
643	+	unsigned char * eip = (unsigned char *)regs[X86_REG_EIP];
644	+
645	+	if (eip == 0)
646	+	return false;
647	+
648	+	transfer_type_t transfer_type = SIGSEGV_TRANSFER_UNKNOWN;
649	+	transfer_size_t transfer_size = SIZE_LONG;
650	+
651	+	int reg = -1;
652	+	int len = 0;
653	+
654	+	// Operand size prefix
655	+	if (*eip == 0x66) {
656	+	eip++;
657	+	len++;
658	+	transfer_size = SIZE_WORD;
659	+	}
660	+
661	+	// Decode instruction
662	+	switch (eip[0]) {
663	+	case 0x0f:
664	+	switch (eip[1]) {
665	+	case 0xb6: // MOVZX r32, r/m8
666	+	case 0xb7: // MOVZX r32, r/m16
667	+	switch (eip[2] & 0xc0) {
668	+	case 0x80:
669	+	reg = (eip[2] >> 3) & 7;
670	+	transfer_type = SIGSEGV_TRANSFER_LOAD;
671	+	break;
672	+	case 0x40:
673	+	reg = (eip[2] >> 3) & 7;
674	+	transfer_type = SIGSEGV_TRANSFER_LOAD;
675	+	break;
676	+	case 0x00:
677	+	reg = (eip[2] >> 3) & 7;
678	+	transfer_type = SIGSEGV_TRANSFER_LOAD;
679	+	break;
680	+	}
681	+	len += 3 + ix86_step_over_modrm(eip + 2);
682	+	break;
683	+	}
684	+	break;
685	+	case 0x8a: // MOV r8, r/m8
686	+	transfer_size = SIZE_BYTE;
687	+	case 0x8b: // MOV r32, r/m32 (or 16-bit operation)
688	+	switch (eip[1] & 0xc0) {
689	+	case 0x80:
690	+	reg = (eip[1] >> 3) & 7;
691	+	transfer_type = SIGSEGV_TRANSFER_LOAD;
692	+	break;
693	+	case 0x40:
694	+	reg = (eip[1] >> 3) & 7;
695	+	transfer_type = SIGSEGV_TRANSFER_LOAD;
696	+	break;
697	+	case 0x00:
698	+	reg = (eip[1] >> 3) & 7;
699	+	transfer_type = SIGSEGV_TRANSFER_LOAD;
700	+	break;
701	+	}
702	+	len += 2 + ix86_step_over_modrm(eip + 1);
703	+	break;
704	+	case 0x88: // MOV r/m8, r8
705	+	transfer_size = SIZE_BYTE;
706	+	case 0x89: // MOV r/m32, r32 (or 16-bit operation)
707	+	switch (eip[1] & 0xc0) {
708	+	case 0x80:
709	+	reg = (eip[1] >> 3) & 7;
710	+	transfer_type = SIGSEGV_TRANSFER_STORE;
711	+	break;
712	+	case 0x40:
713	+	reg = (eip[1] >> 3) & 7;
714	+	transfer_type = SIGSEGV_TRANSFER_STORE;
715	+	break;
716	+	case 0x00:
717	+	reg = (eip[1] >> 3) & 7;
718	+	transfer_type = SIGSEGV_TRANSFER_STORE;
719	+	break;
720	+	}
721	+	len += 2 + ix86_step_over_modrm(eip + 1);
722	+	break;
723	+	}
724	+
725	+	if (transfer_type == SIGSEGV_TRANSFER_UNKNOWN) {
726	+	// Unknown machine code, let it crash. Then patch the decoder
727	+	return false;
728	+	}
729	+
730	+	if (transfer_type == SIGSEGV_TRANSFER_LOAD && reg != -1) {
731	+	static const int x86_reg_map[8] = {
732	+	X86_REG_EAX, X86_REG_ECX, X86_REG_EDX, X86_REG_EBX,
733	+	X86_REG_ESP, X86_REG_EBP, X86_REG_ESI, X86_REG_EDI
734	+	};
735	+
736	+	if (reg < 0 || reg >= 8)
737	+	return false;
738	+
739	+	int rloc = x86_reg_map[reg];
740	+	switch (transfer_size) {
741	+	case SIZE_BYTE:
742	+	regs[rloc] = (regs[rloc] & ~0xff);
743	+	break;
744	+	case SIZE_WORD:
745	+	regs[rloc] = (regs[rloc] & ~0xffff);
746	+	break;
747	+	case SIZE_LONG:
748	+	regs[rloc] = 0;
749	+	break;
750	+	}
751	+	}
752	+
753	+	#if DEBUG
754	+	printf("%08x: %s %s access", regs[X86_REG_EIP],
755	+	transfer_size == SIZE_BYTE ? "byte" : transfer_size == SIZE_WORD ? "word" : "long",
756	+	transfer_type == SIGSEGV_TRANSFER_LOAD ? "read" : "write");
757	+
758	+	if (reg != -1) {
759	+	static const char * x86_reg_str_map[8] = {
760	+	"eax", "ecx", "edx", "ebx",
761	+	"esp", "ebp", "esi", "edi"
762	+	};
763	+	printf(" %s register %%%s", transfer_type == SIGSEGV_TRANSFER_LOAD ? "to" : "from", x86_reg_str_map[reg]);
764	+	}
765	+	printf(", %d bytes instruction\n", len);
766		#endif
767	+
768	+	regs[X86_REG_EIP] += len;
769	+	return true;
770	+	}
771	+	#endif
772	+
773	+	// Decode and skip PPC instruction
774	+	#if (defined(powerpc) || defined(__powerpc__) || defined(__ppc__))
775	+	static bool powerpc_skip_instruction(unsigned int * nip_p, unsigned int * regs)
776	+	{
777	+	instruction_t instr;
778	+	powerpc_decode_instruction(&instr, *nip_p, regs);
779	+
780	+	if (instr.transfer_type == SIGSEGV_TRANSFER_UNKNOWN) {
781	+	// Unknown machine code, let it crash. Then patch the decoder
782	+	return false;
783	+	}
784	+
785	+	#if DEBUG
786	+	printf("%08x: %s %s access", *nip_p,
787	+	instr.transfer_size == SIZE_BYTE ? "byte" : instr.transfer_size == SIZE_WORD ? "word" : "long",
788	+	instr.transfer_type == SIGSEGV_TRANSFER_LOAD ? "read" : "write");
789	+
790	+	if (instr.addr_mode == MODE_U || instr.addr_mode == MODE_UX)
791	+	printf(" r%d (ra = %08x)\n", instr.ra, instr.addr);
792	+	if (instr.transfer_type == SIGSEGV_TRANSFER_LOAD)
793	+	printf(" r%d (rd = 0)\n", instr.rd);
794	+	#endif
795	+
796	+	if (instr.addr_mode == MODE_U || instr.addr_mode == MODE_UX)
797	+	regs[instr.ra] = instr.addr;
798	+	if (instr.transfer_type == SIGSEGV_TRANSFER_LOAD)
799	+	regs[instr.rd] = 0;
800	+
801	+	*nip_p += 4;
802	+	return true;
803	+	}
804		#endif
805		#endif
806
#	Line 138 | Line 808 | static bool sigsegv_do_install_handler(i
808		#ifndef SIGSEGV_FAULT_INSTRUCTION
809		#define SIGSEGV_FAULT_INSTRUCTION               SIGSEGV_INVALID_PC
810		#endif
811	+	#ifndef SIGSEGV_FAULT_HANDLER_ARGLIST_1
812	+	#define SIGSEGV_FAULT_HANDLER_ARGLIST_1 SIGSEGV_FAULT_HANDLER_ARGLIST
813	+	#endif
814	+	#ifndef SIGSEGV_FAULT_HANDLER_INVOKE
815	+	#define SIGSEGV_FAULT_HANDLER_INVOKE(ADDR, IP)  sigsegv_fault_handler(ADDR, IP)
816	+	#endif
817
818		// SIGSEGV recovery supported ?
819		#if defined(SIGSEGV_ALL_SIGNALS) && defined(SIGSEGV_FAULT_HANDLER_ARGLIST) && defined(SIGSEGV_FAULT_ADDRESS)
#	Line 149 | Line 825 | static bool sigsegv_do_install_handler(i
825		*  SIGSEGV global handler
826		*/
827
828	+	#if defined(HAVE_SIGSEGV_RECOVERY) || defined(HAVE_MACH_EXCEPTIONS)
829	+	// This function handles the badaccess to memory.
830	+	// It is called from the signal handler or the exception handler.
831	+	static bool handle_badaccess(SIGSEGV_FAULT_HANDLER_ARGLIST_1)
832	+	{
833	+	sigsegv_address_t fault_address = (sigsegv_address_t)SIGSEGV_FAULT_ADDRESS;
834	+	sigsegv_address_t fault_instruction = (sigsegv_address_t)SIGSEGV_FAULT_INSTRUCTION;
835	+
836	+	// Call user's handler and reinstall the global handler, if required
837	+	switch (SIGSEGV_FAULT_HANDLER_INVOKE(fault_address, fault_instruction)) {
838	+	case SIGSEGV_RETURN_SUCCESS:
839	+	return true;
840	+
841	+	#if HAVE_SIGSEGV_SKIP_INSTRUCTION
842	+	case SIGSEGV_RETURN_SKIP_INSTRUCTION:
843	+	// Call the instruction skipper with the register file
844	+	// available
845	+	if (SIGSEGV_SKIP_INSTRUCTION(SIGSEGV_REGISTER_FILE)) {
846	+	#ifdef HAVE_MACH_EXCEPTIONS
847	+	// Unlike UNIX signals where the thread state
848	+	// is modified off of the stack, in Mach we
849	+	// need to actually call thread_set_state to
850	+	// have the register values updated.
851	+	kern_return_t krc;
852	+
853	+	krc = thread_set_state(thread,
854	+	MACHINE_THREAD_STATE, (thread_state_t)state,
855	+	MACHINE_THREAD_STATE_COUNT);
856	+	MACH_CHECK_ERROR (thread_get_state, krc);
857	+	#endif
858	+	return true;
859	+	}
860	+	break;
861	+	#endif
862	+	}
863	+
864	+	// We can't do anything with the fault_address, dump state?
865	+	if (sigsegv_state_dumper != 0)
866	+	sigsegv_state_dumper(fault_address, fault_instruction);
867	+
868	+	return false;
869	+	}
870	+	#endif
871	+
872	+
873	+	/*
874	+	* There are two mechanisms for handling a bad memory access,
875	+	* Mach exceptions and UNIX signals. The implementation specific
876	+	* code appears below. Its reponsibility is to call handle_badaccess
877	+	* which is the routine that handles the fault in an implementation
878	+	* agnostic manner. The implementation specific code below is then
879	+	* reponsible for checking whether handle_badaccess was able
880	+	* to handle the memory access error and perform any implementation
881	+	* specific tasks necessary afterwards.
882	+	*/
883	+
884	+	#ifdef HAVE_MACH_EXCEPTIONS
885	+	/*
886	+	* We need to forward all exceptions that we do not handle.
887	+	* This is important, there are many exceptions that may be
888	+	* handled by other exception handlers. For example debuggers
889	+	* use exceptions and the exception hander is in another
890	+	* process in such a case. (Timothy J. Wood states in his
891	+	* message to the list that he based this code on that from
892	+	* gdb for Darwin.)
893	+	*/
894	+	static inline kern_return_t
895	+	forward_exception(mach_port_t thread_port,
896	+	mach_port_t task_port,
897	+	exception_type_t exception_type,
898	+	exception_data_t exception_data,
899	+	mach_msg_type_number_t data_count,
900	+	ExceptionPorts *oldExceptionPorts)
901	+	{
902	+	kern_return_t kret;
903	+	unsigned int portIndex;
904	+	mach_port_t port;
905	+	exception_behavior_t behavior;
906	+	thread_state_flavor_t flavor;
907	+	thread_state_t thread_state;
908	+	mach_msg_type_number_t thread_state_count;
909	+
910	+	for (portIndex = 0; portIndex < oldExceptionPorts->maskCount; portIndex++) {
911	+	if (oldExceptionPorts->masks[portIndex] & (1 << exception_type)) {
912	+	// This handler wants the exception
913	+	break;
914	+	}
915	+	}
916	+
917	+	if (portIndex >= oldExceptionPorts->maskCount) {
918	+	fprintf(stderr, "No handler for exception_type = %d. Not fowarding\n", exception_type);
919	+	return KERN_FAILURE;
920	+	}
921	+
922	+	port = oldExceptionPorts->handlers[portIndex];
923	+	behavior = oldExceptionPorts->behaviors[portIndex];
924	+	flavor = oldExceptionPorts->flavors[portIndex];
925	+
926	+	/*
927	+	fprintf(stderr, "forwarding exception, port = 0x%x, behaviour = %d, flavor = %d\n", port, behavior, flavor);
928	+	*/
929	+
930	+	if (behavior != EXCEPTION_DEFAULT) {
931	+	thread_state_count = THREAD_STATE_MAX;
932	+	kret = thread_get_state (thread_port, flavor, thread_state,
933	+	&thread_state_count);
934	+	MACH_CHECK_ERROR (thread_get_state, kret);
935	+	}
936	+
937	+	switch (behavior) {
938	+	case EXCEPTION_DEFAULT:
939	+	// fprintf(stderr, "forwarding to exception_raise\n");
940	+	kret = exception_raise(port, thread_port, task_port, exception_type,
941	+	exception_data, data_count);
942	+	MACH_CHECK_ERROR (exception_raise, kret);
943	+	break;
944	+	case EXCEPTION_STATE:
945	+	// fprintf(stderr, "forwarding to exception_raise_state\n");
946	+	kret = exception_raise_state(port, exception_type, exception_data,
947	+	data_count, &flavor,
948	+	thread_state, thread_state_count,
949	+	thread_state, &thread_state_count);
950	+	MACH_CHECK_ERROR (exception_raise_state, kret);
951	+	break;
952	+	case EXCEPTION_STATE_IDENTITY:
953	+	// fprintf(stderr, "forwarding to exception_raise_state_identity\n");
954	+	kret = exception_raise_state_identity(port, thread_port, task_port,
955	+	exception_type, exception_data,
956	+	data_count, &flavor,
957	+	thread_state, thread_state_count,
958	+	thread_state, &thread_state_count);
959	+	MACH_CHECK_ERROR (exception_raise_state_identity, kret);
960	+	break;
961	+	default:
962	+	fprintf(stderr, "forward_exception got unknown behavior\n");
963	+	break;
964	+	}
965	+
966	+	if (behavior != EXCEPTION_DEFAULT) {
967	+	kret = thread_set_state (thread_port, flavor, thread_state,
968	+	thread_state_count);
969	+	MACH_CHECK_ERROR (thread_set_state, kret);
970	+	}
971	+
972	+	return KERN_SUCCESS;
973	+	}
974	+
975	+	/*
976	+	* This is the code that actually handles the exception.
977	+	* It is called by exc_server. For Darwin 5 Apple changed
978	+	* this a bit from how this family of functions worked in
979	+	* Mach. If you are familiar with that it is a little
980	+	* different. The main variation that concerns us here is
981	+	* that code is an array of exception specific codes and
982	+	* codeCount is a count of the number of codes in the code
983	+	* array. In typical Mach all exceptions have a code
984	+	* and sub-code. It happens to be the case that for a
985	+	* EXC_BAD_ACCESS exception the first entry is the type of
986	+	* bad access that occurred and the second entry is the
987	+	* faulting address so these entries correspond exactly to
988	+	* how the code and sub-code are used on Mach.
989	+	*
990	+	* This is a MIG interface. No code in Basilisk II should
991	+	* call this directley. This has to have external C
992	+	* linkage because that is what exc_server expects.
993	+	*/
994	+	kern_return_t
995	+	catch_exception_raise(mach_port_t exception_port,
996	+	mach_port_t thread,
997	+	mach_port_t task,
998	+	exception_type_t exception,
999	+	exception_data_t code,
1000	+	mach_msg_type_number_t codeCount)
1001	+	{
1002	+	ppc_thread_state_t state;
1003	+	kern_return_t krc;
1004	+
1005	+	if ((exception == EXC_BAD_ACCESS)  && (codeCount >= 2)) {
1006	+	if (handle_badaccess(SIGSEGV_FAULT_HANDLER_ARGS))
1007	+	return KERN_SUCCESS;
1008	+	}
1009	+
1010	+	// In Mach we do not need to remove the exception handler.
1011	+	// If we forward the exception, eventually some exception handler
1012	+	// will take care of this exception.
1013	+	krc = forward_exception(thread, task, exception, code, codeCount, &ports);
1014	+
1015	+	return krc;
1016	+	}
1017	+	#endif
1018	+
1019		#ifdef HAVE_SIGSEGV_RECOVERY
1020	+	// Handle bad memory accesses with signal handler
1021		static void sigsegv_handler(SIGSEGV_FAULT_HANDLER_ARGLIST)
1022		{
1023	<	// Call user's handler and reinstall the global handler, if required
1024	<	if (sigsegv_user_handler((sigsegv_address_t)SIGSEGV_FAULT_ADDRESS, (sigsegv_address_t)SIGSEGV_FAULT_INSTRUCTION)) {
1023	>	// Call handler and reinstall the global handler, if required
1024	>	if (handle_badaccess(SIGSEGV_FAULT_HANDLER_ARGS)) {
1025		#if (defined(HAVE_SIGACTION) ? defined(SIGACTION_NEED_REINSTALL) : defined(SIGNAL_NEED_REINSTALL))
1026		sigsegv_do_install_handler(sig);
1027		#endif
1028	+	return;
1029		}
1030	<	else {
1031	<	// FAIL: reinstall default handler for "safe" crash
1030	>
1031	>	// Failure: reinstall default handler for "safe" crash
1032		#define FAULT_HANDLER(sig) signal(sig, SIG_DFL);
1033	<	SIGSEGV_ALL_SIGNALS
1033	>	SIGSEGV_ALL_SIGNALS
1034		#undef FAULT_HANDLER
166	–	}
1035		}
1036		#endif
1037
#	Line 177 | Line 1045 | static bool sigsegv_do_install_handler(i
1045		{
1046		// Setup SIGSEGV handler to process writes to frame buffer
1047		#ifdef HAVE_SIGACTION
1048	<	struct sigaction vosf_sa;
1049	<	sigemptyset(&vosf_sa.sa_mask);
1050	<	vosf_sa.sa_sigaction = sigsegv_handler;
1051	<	vosf_sa.sa_flags = SA_SIGINFO;
1052	<	return (sigaction(sig, &vosf_sa, 0) == 0);
1048	>	struct sigaction sigsegv_sa;
1049	>	sigemptyset(&sigsegv_sa.sa_mask);
1050	>	sigsegv_sa.sa_sigaction = sigsegv_handler;
1051	>	sigsegv_sa.sa_flags = SA_SIGINFO;
1052	>	return (sigaction(sig, &sigsegv_sa, 0) == 0);
1053		#else
1054		return (signal(sig, (signal_handler)sigsegv_handler) != SIG_ERR);
1055		#endif
#	Line 193 | Line 1061 | static bool sigsegv_do_install_handler(i
1061		{
1062		// Setup SIGSEGV handler to process writes to frame buffer
1063		#ifdef HAVE_SIGACTION
1064	<	struct sigaction vosf_sa;
1065	<	sigemptyset(&vosf_sa.sa_mask);
1066	<	vosf_sa.sa_handler = (signal_handler)sigsegv_handler;
1064	>	struct sigaction sigsegv_sa;
1065	>	sigemptyset(&sigsegv_sa.sa_mask);
1066	>	sigsegv_sa.sa_handler = (signal_handler)sigsegv_handler;
1067	>	sigsegv_sa.sa_flags = 0;
1068		#if !EMULATED_68K && defined(__NetBSD__)
1069	<	sigaddset(&vosf_sa.sa_mask, SIGALRM);
1070	<	vosf_sa.sa_flags = SA_ONSTACK;
202	<	#else
203	<	vosf_sa.sa_flags = 0;
1069	>	sigaddset(&sigsegv_sa.sa_mask, SIGALRM);
1070	>	sigsegv_sa.sa_flags |= SA_ONSTACK;
1071		#endif
1072	<	return (sigaction(sig, &vosf_sa, 0) == 0);
1072	>	return (sigaction(sig, &sigsegv_sa, 0) == 0);
1073		#else
1074		return (signal(sig, (signal_handler)sigsegv_handler) != SIG_ERR);
1075		#endif
1076		}
1077		#endif
1078
1079	<	bool sigsegv_install_handler(sigsegv_handler_t handler)
1079	>	#if defined(HAVE_MACH_EXCEPTIONS)
1080	>	static bool sigsegv_do_install_handler(sigsegv_fault_handler_t handler)
1081		{
1082	<	#ifdef HAVE_SIGSEGV_RECOVERY
1083	<	sigsegv_user_handler = handler;
1082	>	/*
1083	>	* Except for the exception port functions, this should be
1084	>	* pretty much stock Mach. If later you choose to support
1085	>	* other Mach's besides Darwin, just check for __MACH__
1086	>	* here and __APPLE__ where the actual differences are.
1087	>	*/
1088	>	#if defined(__APPLE__) && defined(__MACH__)
1089	>	if (sigsegv_fault_handler != NULL) {
1090	>	sigsegv_fault_handler = handler;
1091	>	return true;
1092	>	}
1093	>
1094	>	kern_return_t krc;
1095	>
1096	>	// create the the exception port
1097	>	krc = mach_port_allocate(mach_task_self(),
1098	>	MACH_PORT_RIGHT_RECEIVE, &_exceptionPort);
1099	>	if (krc != KERN_SUCCESS) {
1100	>	mach_error("mach_port_allocate", krc);
1101	>	return false;
1102	>	}
1103	>
1104	>	// add a port send right
1105	>	krc = mach_port_insert_right(mach_task_self(),
1106	>	_exceptionPort, _exceptionPort,
1107	>	MACH_MSG_TYPE_MAKE_SEND);
1108	>	if (krc != KERN_SUCCESS) {
1109	>	mach_error("mach_port_insert_right", krc);
1110	>	return false;
1111	>	}
1112	>
1113	>	// get the old exception ports
1114	>	ports.maskCount = sizeof (ports.masks) / sizeof (ports.masks[0]);
1115	>	krc = thread_get_exception_ports(mach_thread_self(), EXC_MASK_BAD_ACCESS, ports.masks,
1116	>	&ports.maskCount, ports.handlers, ports.behaviors, ports.flavors);
1117	>	if (krc != KERN_SUCCESS) {
1118	>	mach_error("thread_get_exception_ports", krc);
1119	>	return false;
1120	>	}
1121	>
1122	>	// set the new exception port
1123	>	//
1124	>	// We could have used EXCEPTION_STATE_IDENTITY instead of
1125	>	// EXCEPTION_DEFAULT to get the thread state in the initial
1126	>	// message, but it turns out that in the common case this is not
1127	>	// neccessary. If we need it we can later ask for it from the
1128	>	// suspended thread.
1129	>	//
1130	>	// Even with THREAD_STATE_NONE, Darwin provides the program
1131	>	// counter in the thread state.  The comments in the header file
1132	>	// seem to imply that you can count on the GPR's on an exception
1133	>	// as well but just to be safe I use MACHINE_THREAD_STATE because
1134	>	// you have to ask for all of the GPR's anyway just to get the
1135	>	// program counter. In any case because of update effective
1136	>	// address from immediate and update address from effective
1137	>	// addresses of ra and rb modes (as good an name as any for these
1138	>	// addressing modes) used in PPC instructions, you will need the
1139	>	// GPR state anyway.
1140	>	krc = thread_set_exception_ports(mach_thread_self(), EXC_MASK_BAD_ACCESS, _exceptionPort,
1141	>	EXCEPTION_DEFAULT, MACHINE_THREAD_STATE);
1142	>	if (krc != KERN_SUCCESS) {
1143	>	mach_error("thread_set_exception_ports", krc);
1144	>	return false;
1145	>	}
1146	>
1147	>	// create the exception handler thread
1148	>	if (pthread_create(&exc_thread, NULL, &handleExceptions, NULL) != 0) {
1149	>	(void)fprintf(stderr, "creation of exception thread failed\n");
1150	>	return false;
1151	>	}
1152	>
1153	>	// do not care about the exception thread any longer, let is run standalone
1154	>	(void)pthread_detach(exc_thread);
1155	>
1156	>	sigsegv_fault_handler = handler;
1157	>	return true;
1158	>	#else
1159	>	return false;
1160	>	#endif
1161	>	}
1162	>	#endif
1163	>
1164	>	bool sigsegv_install_handler(sigsegv_fault_handler_t handler)
1165	>	{
1166	>	#if defined(HAVE_SIGSEGV_RECOVERY)
1167		bool success = true;
1168		#define FAULT_HANDLER(sig) success = success && sigsegv_do_install_handler(sig);
1169		SIGSEGV_ALL_SIGNALS
1170		#undef FAULT_HANDLER
1171	+	if (success)
1172	+	sigsegv_fault_handler = handler;
1173		return success;
1174	+	#elif defined(HAVE_MACH_EXCEPTIONS)
1175	+	return sigsegv_do_install_handler(handler);
1176		#else
1177		// FAIL: no siginfo_t nor sigcontext subterfuge is available
1178		return false;
#	Line 231 | Line 1186 | bool sigsegv_install_handler(sigsegv_han
1186
1187		void sigsegv_deinstall_handler(void)
1188		{
1189	+	// We do nothing for Mach exceptions, the thread would need to be
1190	+	// suspended if not already so, and we might mess with other
1191	+	// exception handlers that came after we registered ours. There is
1192	+	// no need to remove the exception handler, in fact this function is
1193	+	// not called anywhere in Basilisk II.
1194		#ifdef HAVE_SIGSEGV_RECOVERY
1195	<	sigsegv_user_handler = 0;
1195	>	sigsegv_fault_handler = 0;
1196		#define FAULT_HANDLER(sig) signal(sig, SIG_DFL);
1197		SIGSEGV_ALL_SIGNALS
1198		#undef FAULT_HANDLER
1199		#endif
1200		}
1201
1202	+
1203	+	/*
1204	+	*  Set callback function when we cannot handle the fault
1205	+	*/
1206	+
1207	+	void sigsegv_set_dump_state(sigsegv_state_dumper_t handler)
1208	+	{
1209	+	sigsegv_state_dumper = handler;
1210	+	}
1211	+
1212	+
1213		/*
1214		*  Test program used for configure/test
1215		*/
1216
1217	<	#ifdef CONFIGURE_TEST
1217	>	#ifdef CONFIGURE_TEST_SIGSEGV_RECOVERY
1218		#include <stdio.h>
1219		#include <stdlib.h>
249	–	#include <unistd.h>
1220		#include <fcntl.h>
1221		#include <sys/mman.h>
1222	+	#include "vm_alloc.h"
1223	+
1224	+	const int REF_INDEX = 123;
1225	+	const int REF_VALUE = 45;
1226
253	–	static caddr_t page = 0;
1227		static int page_size;
1228	<	static int handler_called = 0;
1228	>	static volatile char * page = 0;
1229	>	static volatile int handler_called = 0;
1230	>
1231	>	#ifdef __GNUC__
1232	>	// Code range where we expect the fault to come from
1233	>	static void *b_region, *e_region;
1234	>	#endif
1235
1236	<	static bool sigsegv_test_handler(sigsegv_address_t fault_address, sigsegv_address_t instruction_address)
1236	>	static sigsegv_return_t sigsegv_test_handler(sigsegv_address_t fault_address, sigsegv_address_t instruction_address)
1237		{
1238		handler_called++;
1239	<	if ((fault_address - 123) != page)
1240	<	exit(1);
1241	<	if (mprotect((caddr_t)((unsigned long)fault_address & -page_size), page_size, PROT_READ | PROT_WRITE) != 0)
1242	<	exit(1);
1243	<	return true;
1239	>	if ((fault_address - REF_INDEX) != page)
1240	>	exit(10);
1241	>	#ifdef __GNUC__
1242	>	// Make sure reported fault instruction address falls into
1243	>	// expected code range
1244	>	if (instruction_address != SIGSEGV_INVALID_PC
1245	>	&& ((instruction_address <  (sigsegv_address_t)b_region) ||
1246	>	(instruction_address >= (sigsegv_address_t)e_region)))
1247	>	exit(11);
1248	>	#endif
1249	>	if (vm_protect((char *)((unsigned long)fault_address & -page_size), page_size, VM_PAGE_READ | VM_PAGE_WRITE) != 0)
1250	>	exit(12);
1251	>	return SIGSEGV_RETURN_SUCCESS;
1252	>	}
1253	>
1254	>	#ifdef HAVE_SIGSEGV_SKIP_INSTRUCTION
1255	>	static sigsegv_return_t sigsegv_insn_handler(sigsegv_address_t fault_address, sigsegv_address_t instruction_address)
1256	>	{
1257	>	if (((unsigned long)fault_address - (unsigned long)page) < page_size) {
1258	>	#ifdef __GNUC__
1259	>	// Make sure reported fault instruction address falls into
1260	>	// expected code range
1261	>	if (instruction_address != SIGSEGV_INVALID_PC
1262	>	&& ((instruction_address <  (sigsegv_address_t)b_region) ||
1263	>	(instruction_address >= (sigsegv_address_t)e_region)))
1264	>	return SIGSEGV_RETURN_FAILURE;
1265	>	#endif
1266	>	return SIGSEGV_RETURN_SKIP_INSTRUCTION;
1267	>	}
1268	>
1269	>	return SIGSEGV_RETURN_FAILURE;
1270		}
1271	+	#endif
1272
1273		int main(void)
1274		{
1275	<	int zero_fd = open("/dev/zero", O_RDWR);
270	<	if (zero_fd < 0)
1275	>	if (vm_init() < 0)
1276		return 1;
1277
1278		page_size = getpagesize();
1279	<	page = (caddr_t)mmap(0, page_size, PROT_READ, MAP_PRIVATE, zero_fd, 0);
1280	<	if (page == MAP_FAILED)
276	<	return 1;
1279	>	if ((page = (char *)vm_acquire(page_size)) == VM_MAP_FAILED)
1280	>	return 2;
1281
1282	<	if (!sigsegv_install_handler(sigsegv_test_handler))
1283	<	return 1;
1282	>	memset((void *)page, 0, page_size);
1283	>	if (vm_protect((char *)page, page_size, VM_PAGE_READ) < 0)
1284	>	return 3;
1285
1286	<	page[123] = 45;
1287	<	page[123] = 45;
1286	>	if (!sigsegv_install_handler(sigsegv_test_handler))
1287	>	return 4;
1288
1289	+	#ifdef __GNUC__
1290	+	b_region = &&L_b_region1;
1291	+	e_region = &&L_e_region1;
1292	+	#endif
1293	+	L_b_region1:
1294	+	page[REF_INDEX] = REF_VALUE;
1295	+	if (page[REF_INDEX] != REF_VALUE)
1296	+	exit(20);
1297	+	page[REF_INDEX] = REF_VALUE;
1298	+	L_e_region1:
1299	+
1300		if (handler_called != 1)
1301	<	return 1;
1301	>	return 5;
1302
1303	+	#ifdef HAVE_SIGSEGV_SKIP_INSTRUCTION
1304	+	if (!sigsegv_install_handler(sigsegv_insn_handler))
1305	+	return 6;
1306	+
1307	+	if (vm_protect((char *)page, page_size, VM_PAGE_READ | VM_PAGE_WRITE) < 0)
1308	+	return 7;
1309	+
1310	+	for (int i = 0; i < page_size; i++)
1311	+	page[i] = (i + 1) % page_size;
1312	+
1313	+	if (vm_protect((char *)page, page_size, VM_PAGE_NOACCESS) < 0)
1314	+	return 8;
1315	+
1316	+	#define TEST_SKIP_INSTRUCTION(TYPE) do {                                \
1317	+	const unsigned int TAG = 0x12345678;                    \
1318	+	TYPE data = *((TYPE *)(page + sizeof(TYPE)));   \
1319	+	volatile unsigned int effect = data + TAG;              \
1320	+	if (effect != TAG)                                                              \
1321	+	return 9;                                                                       \
1322	+	} while (0)
1323	+
1324	+	#ifdef __GNUC__
1325	+	b_region = &&L_b_region2;
1326	+	e_region = &&L_e_region2;
1327	+	#endif
1328	+	L_b_region2:
1329	+	TEST_SKIP_INSTRUCTION(unsigned char);
1330	+	TEST_SKIP_INSTRUCTION(unsigned short);
1331	+	TEST_SKIP_INSTRUCTION(unsigned int);
1332	+	L_e_region2:
1333	+	#endif
1334	+
1335	+	vm_exit();
1336		return 0;
1337		}
1338		#endif
1339	+
1340	+
1341	+
1342	+
1343	+
1344	+
1345	+
1346	+
1347	+
1348	+
1349	+
1350	+
1351	+
1352	+
1353	+

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