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root/cebix/BasiliskII/src/Unix/sigsegv.cpp
Revision: 1.7
Committed: 2002-01-15T14:58:37Z (22 years, 9 months ago) by cebix
Branch: MAIN
CVS Tags: snapshot-15012002
Changes since 1.6: +1 -1 lines
Log Message:
- documentation updates
- 2001 -> 2002
- version 0.9 -> 1.0

File Contents

# User Rev Content
1 gbeauche 1.1 /*
2     * sigsegv.cpp - SIGSEGV signals support
3     *
4     * Derived from Bruno Haible's work on his SIGSEGV library for clisp
5     * <http://clisp.sourceforge.net/>
6     *
7 cebix 1.7 * Basilisk II (C) 1997-2002 Christian Bauer
8 gbeauche 1.1 *
9     * This program is free software; you can redistribute it and/or modify
10     * it under the terms of the GNU General Public License as published by
11     * the Free Software Foundation; either version 2 of the License, or
12     * (at your option) any later version.
13     *
14     * This program is distributed in the hope that it will be useful,
15     * but WITHOUT ANY WARRANTY; without even the implied warranty of
16     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17     * GNU General Public License for more details.
18     *
19     * You should have received a copy of the GNU General Public License
20     * along with this program; if not, write to the Free Software
21     * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22     */
23    
24     #ifdef HAVE_UNISTD_H
25     #include <unistd.h>
26     #endif
27    
28     #ifdef HAVE_CONFIG_H
29     #include "config.h"
30     #endif
31    
32     #include <signal.h>
33     #include "sigsegv.h"
34    
35     // Return value type of a signal handler (standard type if not defined)
36     #ifndef RETSIGTYPE
37     #define RETSIGTYPE void
38     #endif
39    
40     // Type of the system signal handler
41     typedef RETSIGTYPE (*signal_handler)(int);
42    
43     // User's SIGSEGV handler
44     static sigsegv_handler_t sigsegv_user_handler = 0;
45    
46     // Actual SIGSEGV handler installer
47     static bool sigsegv_do_install_handler(int sig);
48    
49    
50     /*
51     * OS-dependant SIGSEGV signals support section
52     */
53    
54     #if HAVE_SIGINFO_T
55     // Generic extended signal handler
56     #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
57 gbeauche 1.5 #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, siginfo_t *sip, void *scp
58 gbeauche 1.1 #define SIGSEGV_FAULT_ADDRESS sip->si_addr
59 gbeauche 1.5 #if defined(__linux__)
60 gbeauche 1.6 #if (defined(i386) || defined(__i386__))
61     #include <sys/ucontext.h>
62     #define SIGSEGV_FAULT_INSTRUCTION (((ucontext_t *)scp)->uc_mcontext.gregs[14]) /* should use REG_EIP instead */
63     #endif
64 gbeauche 1.5 #if (defined(ia64) || defined(__ia64__))
65     #define SIGSEGV_FAULT_INSTRUCTION (((struct sigcontext *)scp)->sc_ip & ~0x3ULL) /* slot number is in bits 0 and 1 */
66     #endif
67     #endif
68 gbeauche 1.1 #endif
69    
70     #if HAVE_SIGCONTEXT_SUBTERFUGE
71     // Linux kernels prior to 2.4 ?
72     #if defined(__linux__)
73     #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
74     #if (defined(i386) || defined(__i386__))
75     #include <asm/sigcontext.h>
76     #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, struct sigcontext scs
77     #define SIGSEGV_FAULT_ADDRESS scs.cr2
78     #define SIGSEGV_FAULT_INSTRUCTION scs.eip
79     #endif
80     #if (defined(sparc) || defined(__sparc__))
81     #include <asm/sigcontext.h>
82 gbeauche 1.5 #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp, char *addr
83 gbeauche 1.1 #define SIGSEGV_FAULT_ADDRESS addr
84     #endif
85     #if (defined(powerpc) || defined(__powerpc__))
86     #include <asm/sigcontext.h>
87 gbeauche 1.4 #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, struct sigcontext *scp
88 gbeauche 1.1 #define SIGSEGV_FAULT_ADDRESS scp->regs->dar
89     #define SIGSEGV_FAULT_INSTRUCTION scp->regs->nip
90     #endif
91 gbeauche 1.4 #if (defined(alpha) || defined(__alpha__))
92     #include <asm/sigcontext.h>
93     #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
94     #define SIGSEGV_FAULT_ADDRESS get_fault_address(scp)
95     #define SIGSEGV_FAULT_INSTRUCTION scp->sc_pc
96    
97     // From Boehm's GC 6.0alpha8
98     static sigsegv_address_t get_fault_address(struct sigcontext *scp)
99     {
100     unsigned int instruction = *((unsigned int *)(scp->sc_pc));
101     unsigned long fault_address = scp->sc_regs[(instruction >> 16) & 0x1f];
102     fault_address += (signed long)(signed short)(instruction & 0xffff);
103     return (sigsegv_address_t)fault_address;
104     }
105     #endif
106 gbeauche 1.1 #endif
107    
108     // Irix 5 or 6 on MIPS
109     #if (defined(sgi) || defined(__sgi)) && (defined(SYSTYPE_SVR4) || defined(__SYSTYPE_SVR4))
110     #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
111     #define SIGSEGV_FAULT_ADDRESS scp->sc_badvaddr
112     #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
113     #endif
114    
115     // OSF/1 on Alpha
116     #if defined(__osf__)
117     #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
118     #define SIGSEGV_FAULT_ADDRESS scp->sc_traparg_a0
119     #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
120     #endif
121    
122     // AIX
123     #if defined(_AIX)
124     #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
125     #define SIGSEGV_FAULT_ADDRESS scp->sc_jmpbuf.jmp_context.o_vaddr
126     #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
127     #endif
128    
129     // NetBSD or FreeBSD
130     #if defined(__NetBSD__) || defined(__FreeBSD__)
131     #if (defined(m68k) || defined(__m68k__))
132     #include <m68k/frame.h>
133     #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
134     #define SIGSEGV_FAULT_ADDRESS ({ \
135     struct sigstate { \
136     int ss_flags; \
137     struct frame ss_frame; \
138     }; \
139     struct sigstate *state = (struct sigstate *)scp->sc_ap; \
140     char *fault_addr; \
141     switch (state->ss_frame.f_format) { \
142     case 7: /* 68040 access error */ \
143     /* "code" is sometimes unreliable (i.e. contains NULL or a bogus address), reason unknown */ \
144     fault_addr = state->ss_frame.f_fmt7.f_fa; \
145     break; \
146     default: \
147     fault_addr = (char *)code; \
148     break; \
149     } \
150     fault_addr; \
151     })
152     #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
153     #else
154     #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, void *scp, char *addr
155     #define SIGSEGV_FAULT_ADDRESS addr
156     #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGBUS)
157     #endif
158     #endif
159 gbeauche 1.4
160     // MacOS X
161     #if defined(__APPLE__) && defined(__MACH__)
162     #if (defined(ppc) || defined(__ppc__))
163     #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
164     #define SIGSEGV_FAULT_ADDRESS get_fault_address(scp)
165     #define SIGSEGV_FAULT_INSTRUCTION scp->sc_ir
166     #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGBUS)
167    
168     // From Boehm's GC 6.0alpha8
169     #define EXTRACT_OP1(iw) (((iw) & 0xFC000000) >> 26)
170     #define EXTRACT_OP2(iw) (((iw) & 0x000007FE) >> 1)
171     #define EXTRACT_REGA(iw) (((iw) & 0x001F0000) >> 16)
172     #define EXTRACT_REGB(iw) (((iw) & 0x03E00000) >> 21)
173     #define EXTRACT_REGC(iw) (((iw) & 0x0000F800) >> 11)
174     #define EXTRACT_DISP(iw) ((short *) &(iw))[1]
175    
176     static sigsegv_address_t get_fault_address(struct sigcontext *scp)
177     {
178     unsigned int instr = *((unsigned int *) scp->sc_ir);
179     unsigned int * regs = &((unsigned int *) scp->sc_regs)[2];
180     int disp = 0, tmp;
181     unsigned int baseA = 0, baseB = 0;
182     unsigned int addr, alignmask = 0xFFFFFFFF;
183    
184     switch(EXTRACT_OP1(instr)) {
185     case 38: /* stb */
186     case 39: /* stbu */
187     case 54: /* stfd */
188     case 55: /* stfdu */
189     case 52: /* stfs */
190     case 53: /* stfsu */
191     case 44: /* sth */
192     case 45: /* sthu */
193     case 47: /* stmw */
194     case 36: /* stw */
195     case 37: /* stwu */
196     tmp = EXTRACT_REGA(instr);
197     if(tmp > 0)
198     baseA = regs[tmp];
199     disp = EXTRACT_DISP(instr);
200     break;
201     case 31:
202     switch(EXTRACT_OP2(instr)) {
203     case 86: /* dcbf */
204     case 54: /* dcbst */
205     case 1014: /* dcbz */
206     case 247: /* stbux */
207     case 215: /* stbx */
208     case 759: /* stfdux */
209     case 727: /* stfdx */
210     case 983: /* stfiwx */
211     case 695: /* stfsux */
212     case 663: /* stfsx */
213     case 918: /* sthbrx */
214     case 439: /* sthux */
215     case 407: /* sthx */
216     case 661: /* stswx */
217     case 662: /* stwbrx */
218     case 150: /* stwcx. */
219     case 183: /* stwux */
220     case 151: /* stwx */
221     case 135: /* stvebx */
222     case 167: /* stvehx */
223     case 199: /* stvewx */
224     case 231: /* stvx */
225     case 487: /* stvxl */
226     tmp = EXTRACT_REGA(instr);
227     if(tmp > 0)
228     baseA = regs[tmp];
229     baseB = regs[EXTRACT_REGC(instr)];
230     /* determine Altivec alignment mask */
231     switch(EXTRACT_OP2(instr)) {
232     case 167: /* stvehx */
233     alignmask = 0xFFFFFFFE;
234     break;
235     case 199: /* stvewx */
236     alignmask = 0xFFFFFFFC;
237     break;
238     case 231: /* stvx */
239     alignmask = 0xFFFFFFF0;
240     break;
241     case 487: /* stvxl */
242     alignmask = 0xFFFFFFF0;
243     break;
244     }
245     break;
246     case 725: /* stswi */
247     tmp = EXTRACT_REGA(instr);
248     if(tmp > 0)
249     baseA = regs[tmp];
250     break;
251     default: /* ignore instruction */
252     return 0;
253     break;
254     }
255     break;
256     default: /* ignore instruction */
257     return 0;
258     break;
259     }
260    
261     addr = (baseA + baseB) + disp;
262     addr &= alignmask;
263     return (sigsegv_address_t)addr;
264     }
265     #endif
266     #endif
267 gbeauche 1.1 #endif
268    
269     // Fallbacks
270     #ifndef SIGSEGV_FAULT_INSTRUCTION
271     #define SIGSEGV_FAULT_INSTRUCTION SIGSEGV_INVALID_PC
272     #endif
273    
274 gbeauche 1.2 // SIGSEGV recovery supported ?
275     #if defined(SIGSEGV_ALL_SIGNALS) && defined(SIGSEGV_FAULT_HANDLER_ARGLIST) && defined(SIGSEGV_FAULT_ADDRESS)
276     #define HAVE_SIGSEGV_RECOVERY
277     #endif
278    
279 gbeauche 1.1
280     /*
281     * SIGSEGV global handler
282     */
283    
284 gbeauche 1.2 #ifdef HAVE_SIGSEGV_RECOVERY
285 gbeauche 1.1 static void sigsegv_handler(SIGSEGV_FAULT_HANDLER_ARGLIST)
286     {
287     // Call user's handler and reinstall the global handler, if required
288     if (sigsegv_user_handler((sigsegv_address_t)SIGSEGV_FAULT_ADDRESS, (sigsegv_address_t)SIGSEGV_FAULT_INSTRUCTION)) {
289     #if (defined(HAVE_SIGACTION) ? defined(SIGACTION_NEED_REINSTALL) : defined(SIGNAL_NEED_REINSTALL))
290     sigsegv_do_install_handler(sig);
291     #endif
292     }
293     else {
294     // FAIL: reinstall default handler for "safe" crash
295     #define FAULT_HANDLER(sig) signal(sig, SIG_DFL);
296     SIGSEGV_ALL_SIGNALS
297     #undef FAULT_HANDLER
298     }
299     }
300 gbeauche 1.2 #endif
301 gbeauche 1.1
302    
303     /*
304     * SIGSEGV handler initialization
305     */
306    
307     #if defined(HAVE_SIGINFO_T)
308     static bool sigsegv_do_install_handler(int sig)
309     {
310     // Setup SIGSEGV handler to process writes to frame buffer
311     #ifdef HAVE_SIGACTION
312     struct sigaction vosf_sa;
313     sigemptyset(&vosf_sa.sa_mask);
314     vosf_sa.sa_sigaction = sigsegv_handler;
315     vosf_sa.sa_flags = SA_SIGINFO;
316     return (sigaction(sig, &vosf_sa, 0) == 0);
317     #else
318     return (signal(sig, (signal_handler)sigsegv_handler) != SIG_ERR);
319     #endif
320     }
321 gbeauche 1.2 #endif
322    
323     #if defined(HAVE_SIGCONTEXT_SUBTERFUGE)
324 gbeauche 1.1 static bool sigsegv_do_install_handler(int sig)
325     {
326     // Setup SIGSEGV handler to process writes to frame buffer
327     #ifdef HAVE_SIGACTION
328     struct sigaction vosf_sa;
329     sigemptyset(&vosf_sa.sa_mask);
330     vosf_sa.sa_handler = (signal_handler)sigsegv_handler;
331     #if !EMULATED_68K && defined(__NetBSD__)
332     sigaddset(&vosf_sa.sa_mask, SIGALRM);
333     vosf_sa.sa_flags = SA_ONSTACK;
334     #else
335     vosf_sa.sa_flags = 0;
336     #endif
337     return (sigaction(sig, &vosf_sa, 0) == 0);
338     #else
339     return (signal(sig, (signal_handler)sigsegv_handler) != SIG_ERR);
340     #endif
341     }
342     #endif
343    
344     bool sigsegv_install_handler(sigsegv_handler_t handler)
345     {
346 gbeauche 1.2 #ifdef HAVE_SIGSEGV_RECOVERY
347 gbeauche 1.1 sigsegv_user_handler = handler;
348     bool success = true;
349     #define FAULT_HANDLER(sig) success = success && sigsegv_do_install_handler(sig);
350     SIGSEGV_ALL_SIGNALS
351     #undef FAULT_HANDLER
352     return success;
353     #else
354     // FAIL: no siginfo_t nor sigcontext subterfuge is available
355     return false;
356     #endif
357     }
358    
359    
360     /*
361     * SIGSEGV handler deinitialization
362     */
363    
364     void sigsegv_deinstall_handler(void)
365     {
366 gbeauche 1.2 #ifdef HAVE_SIGSEGV_RECOVERY
367 gbeauche 1.1 sigsegv_user_handler = 0;
368     #define FAULT_HANDLER(sig) signal(sig, SIG_DFL);
369     SIGSEGV_ALL_SIGNALS
370     #undef FAULT_HANDLER
371 gbeauche 1.2 #endif
372 gbeauche 1.1 }
373    
374     /*
375     * Test program used for configure/test
376     */
377    
378 gbeauche 1.4 #ifdef CONFIGURE_TEST_SIGSEGV_RECOVERY
379 gbeauche 1.1 #include <stdio.h>
380     #include <stdlib.h>
381     #include <fcntl.h>
382     #include <sys/mman.h>
383 gbeauche 1.4 #include "vm_alloc.h"
384 gbeauche 1.1
385     static int page_size;
386 gbeauche 1.3 static volatile char * page = 0;
387     static volatile int handler_called = 0;
388 gbeauche 1.1
389     static bool sigsegv_test_handler(sigsegv_address_t fault_address, sigsegv_address_t instruction_address)
390     {
391     handler_called++;
392     if ((fault_address - 123) != page)
393     exit(1);
394 gbeauche 1.4 if (vm_protect((char *)((unsigned long)fault_address & -page_size), page_size, VM_PAGE_READ | VM_PAGE_WRITE) != 0)
395 gbeauche 1.1 exit(1);
396     return true;
397     }
398    
399     int main(void)
400     {
401 gbeauche 1.4 if (vm_init() < 0)
402 gbeauche 1.1 return 1;
403    
404     page_size = getpagesize();
405 gbeauche 1.4 if ((page = (char *)vm_acquire(page_size)) == VM_MAP_FAILED)
406     return 1;
407    
408     if (vm_protect((char *)page, page_size, VM_PAGE_READ) < 0)
409 gbeauche 1.1 return 1;
410    
411     if (!sigsegv_install_handler(sigsegv_test_handler))
412     return 1;
413    
414     page[123] = 45;
415     page[123] = 45;
416    
417     if (handler_called != 1)
418     return 1;
419    
420 gbeauche 1.4 vm_exit();
421 gbeauche 1.1 return 0;
422     }
423     #endif