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root/cebix/BasiliskII/src/Unix/sigsegv.cpp
Revision: 1.9
Committed: 2002-03-16T21:36:12Z (22 years, 8 months ago) by gbeauche
Branch: MAIN
Changes since 1.8: +4 -0 lines
Log Message:
- Add fault instruction recovery for Linux/ppc and siginfo_t handlers

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 cebix 1.8 #if defined(__NetBSD__) || defined(__FreeBSD__)
57     #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGBUS)
58     #else
59 gbeauche 1.1 #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
60 cebix 1.8 #endif
61 gbeauche 1.5 #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, siginfo_t *sip, void *scp
62 gbeauche 1.1 #define SIGSEGV_FAULT_ADDRESS sip->si_addr
63 gbeauche 1.5 #if defined(__linux__)
64 gbeauche 1.6 #if (defined(i386) || defined(__i386__))
65     #include <sys/ucontext.h>
66     #define SIGSEGV_FAULT_INSTRUCTION (((ucontext_t *)scp)->uc_mcontext.gregs[14]) /* should use REG_EIP instead */
67     #endif
68 gbeauche 1.5 #if (defined(ia64) || defined(__ia64__))
69     #define SIGSEGV_FAULT_INSTRUCTION (((struct sigcontext *)scp)->sc_ip & ~0x3ULL) /* slot number is in bits 0 and 1 */
70     #endif
71 gbeauche 1.9 #if (defined(powerpc) || defined(__powerpc__))
72     #include <sys/ucontext.h>
73     #define SIGSEGV_FAULT_INSTRUCTION (((ucontext_t *)scp)->uc_mcontext.regs->nip)
74     #endif
75 gbeauche 1.5 #endif
76 gbeauche 1.1 #endif
77    
78     #if HAVE_SIGCONTEXT_SUBTERFUGE
79     // Linux kernels prior to 2.4 ?
80     #if defined(__linux__)
81     #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
82     #if (defined(i386) || defined(__i386__))
83     #include <asm/sigcontext.h>
84     #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, struct sigcontext scs
85     #define SIGSEGV_FAULT_ADDRESS scs.cr2
86     #define SIGSEGV_FAULT_INSTRUCTION scs.eip
87     #endif
88     #if (defined(sparc) || defined(__sparc__))
89     #include <asm/sigcontext.h>
90 gbeauche 1.5 #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp, char *addr
91 gbeauche 1.1 #define SIGSEGV_FAULT_ADDRESS addr
92     #endif
93     #if (defined(powerpc) || defined(__powerpc__))
94     #include <asm/sigcontext.h>
95 gbeauche 1.4 #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, struct sigcontext *scp
96 gbeauche 1.1 #define SIGSEGV_FAULT_ADDRESS scp->regs->dar
97     #define SIGSEGV_FAULT_INSTRUCTION scp->regs->nip
98     #endif
99 gbeauche 1.4 #if (defined(alpha) || defined(__alpha__))
100     #include <asm/sigcontext.h>
101     #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
102     #define SIGSEGV_FAULT_ADDRESS get_fault_address(scp)
103     #define SIGSEGV_FAULT_INSTRUCTION scp->sc_pc
104    
105     // From Boehm's GC 6.0alpha8
106     static sigsegv_address_t get_fault_address(struct sigcontext *scp)
107     {
108     unsigned int instruction = *((unsigned int *)(scp->sc_pc));
109     unsigned long fault_address = scp->sc_regs[(instruction >> 16) & 0x1f];
110     fault_address += (signed long)(signed short)(instruction & 0xffff);
111     return (sigsegv_address_t)fault_address;
112     }
113     #endif
114 gbeauche 1.1 #endif
115    
116     // Irix 5 or 6 on MIPS
117     #if (defined(sgi) || defined(__sgi)) && (defined(SYSTYPE_SVR4) || defined(__SYSTYPE_SVR4))
118     #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
119     #define SIGSEGV_FAULT_ADDRESS scp->sc_badvaddr
120     #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
121     #endif
122    
123     // OSF/1 on Alpha
124     #if defined(__osf__)
125     #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
126     #define SIGSEGV_FAULT_ADDRESS scp->sc_traparg_a0
127     #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
128     #endif
129    
130     // AIX
131     #if defined(_AIX)
132     #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
133     #define SIGSEGV_FAULT_ADDRESS scp->sc_jmpbuf.jmp_context.o_vaddr
134     #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
135     #endif
136    
137     // NetBSD or FreeBSD
138     #if defined(__NetBSD__) || defined(__FreeBSD__)
139     #if (defined(m68k) || defined(__m68k__))
140     #include <m68k/frame.h>
141     #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
142     #define SIGSEGV_FAULT_ADDRESS ({ \
143     struct sigstate { \
144     int ss_flags; \
145     struct frame ss_frame; \
146     }; \
147     struct sigstate *state = (struct sigstate *)scp->sc_ap; \
148     char *fault_addr; \
149     switch (state->ss_frame.f_format) { \
150     case 7: /* 68040 access error */ \
151     /* "code" is sometimes unreliable (i.e. contains NULL or a bogus address), reason unknown */ \
152     fault_addr = state->ss_frame.f_fmt7.f_fa; \
153     break; \
154     default: \
155     fault_addr = (char *)code; \
156     break; \
157     } \
158     fault_addr; \
159     })
160     #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
161     #else
162     #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, void *scp, char *addr
163     #define SIGSEGV_FAULT_ADDRESS addr
164     #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGBUS)
165     #endif
166     #endif
167 gbeauche 1.4
168     // MacOS X
169     #if defined(__APPLE__) && defined(__MACH__)
170     #if (defined(ppc) || defined(__ppc__))
171     #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
172     #define SIGSEGV_FAULT_ADDRESS get_fault_address(scp)
173     #define SIGSEGV_FAULT_INSTRUCTION scp->sc_ir
174     #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGBUS)
175    
176     // From Boehm's GC 6.0alpha8
177     #define EXTRACT_OP1(iw) (((iw) & 0xFC000000) >> 26)
178     #define EXTRACT_OP2(iw) (((iw) & 0x000007FE) >> 1)
179     #define EXTRACT_REGA(iw) (((iw) & 0x001F0000) >> 16)
180     #define EXTRACT_REGB(iw) (((iw) & 0x03E00000) >> 21)
181     #define EXTRACT_REGC(iw) (((iw) & 0x0000F800) >> 11)
182     #define EXTRACT_DISP(iw) ((short *) &(iw))[1]
183    
184     static sigsegv_address_t get_fault_address(struct sigcontext *scp)
185     {
186     unsigned int instr = *((unsigned int *) scp->sc_ir);
187     unsigned int * regs = &((unsigned int *) scp->sc_regs)[2];
188     int disp = 0, tmp;
189     unsigned int baseA = 0, baseB = 0;
190     unsigned int addr, alignmask = 0xFFFFFFFF;
191    
192     switch(EXTRACT_OP1(instr)) {
193     case 38: /* stb */
194     case 39: /* stbu */
195     case 54: /* stfd */
196     case 55: /* stfdu */
197     case 52: /* stfs */
198     case 53: /* stfsu */
199     case 44: /* sth */
200     case 45: /* sthu */
201     case 47: /* stmw */
202     case 36: /* stw */
203     case 37: /* stwu */
204     tmp = EXTRACT_REGA(instr);
205     if(tmp > 0)
206     baseA = regs[tmp];
207     disp = EXTRACT_DISP(instr);
208     break;
209     case 31:
210     switch(EXTRACT_OP2(instr)) {
211     case 86: /* dcbf */
212     case 54: /* dcbst */
213     case 1014: /* dcbz */
214     case 247: /* stbux */
215     case 215: /* stbx */
216     case 759: /* stfdux */
217     case 727: /* stfdx */
218     case 983: /* stfiwx */
219     case 695: /* stfsux */
220     case 663: /* stfsx */
221     case 918: /* sthbrx */
222     case 439: /* sthux */
223     case 407: /* sthx */
224     case 661: /* stswx */
225     case 662: /* stwbrx */
226     case 150: /* stwcx. */
227     case 183: /* stwux */
228     case 151: /* stwx */
229     case 135: /* stvebx */
230     case 167: /* stvehx */
231     case 199: /* stvewx */
232     case 231: /* stvx */
233     case 487: /* stvxl */
234     tmp = EXTRACT_REGA(instr);
235     if(tmp > 0)
236     baseA = regs[tmp];
237     baseB = regs[EXTRACT_REGC(instr)];
238     /* determine Altivec alignment mask */
239     switch(EXTRACT_OP2(instr)) {
240     case 167: /* stvehx */
241     alignmask = 0xFFFFFFFE;
242     break;
243     case 199: /* stvewx */
244     alignmask = 0xFFFFFFFC;
245     break;
246     case 231: /* stvx */
247     alignmask = 0xFFFFFFF0;
248     break;
249     case 487: /* stvxl */
250     alignmask = 0xFFFFFFF0;
251     break;
252     }
253     break;
254     case 725: /* stswi */
255     tmp = EXTRACT_REGA(instr);
256     if(tmp > 0)
257     baseA = regs[tmp];
258     break;
259     default: /* ignore instruction */
260     return 0;
261     break;
262     }
263     break;
264     default: /* ignore instruction */
265     return 0;
266     break;
267     }
268    
269     addr = (baseA + baseB) + disp;
270     addr &= alignmask;
271     return (sigsegv_address_t)addr;
272     }
273     #endif
274     #endif
275 gbeauche 1.1 #endif
276    
277     // Fallbacks
278     #ifndef SIGSEGV_FAULT_INSTRUCTION
279     #define SIGSEGV_FAULT_INSTRUCTION SIGSEGV_INVALID_PC
280     #endif
281    
282 gbeauche 1.2 // SIGSEGV recovery supported ?
283     #if defined(SIGSEGV_ALL_SIGNALS) && defined(SIGSEGV_FAULT_HANDLER_ARGLIST) && defined(SIGSEGV_FAULT_ADDRESS)
284     #define HAVE_SIGSEGV_RECOVERY
285     #endif
286    
287 gbeauche 1.1
288     /*
289     * SIGSEGV global handler
290     */
291    
292 gbeauche 1.2 #ifdef HAVE_SIGSEGV_RECOVERY
293 gbeauche 1.1 static void sigsegv_handler(SIGSEGV_FAULT_HANDLER_ARGLIST)
294     {
295     // Call user's handler and reinstall the global handler, if required
296     if (sigsegv_user_handler((sigsegv_address_t)SIGSEGV_FAULT_ADDRESS, (sigsegv_address_t)SIGSEGV_FAULT_INSTRUCTION)) {
297     #if (defined(HAVE_SIGACTION) ? defined(SIGACTION_NEED_REINSTALL) : defined(SIGNAL_NEED_REINSTALL))
298     sigsegv_do_install_handler(sig);
299     #endif
300     }
301     else {
302     // FAIL: reinstall default handler for "safe" crash
303     #define FAULT_HANDLER(sig) signal(sig, SIG_DFL);
304     SIGSEGV_ALL_SIGNALS
305     #undef FAULT_HANDLER
306     }
307     }
308 gbeauche 1.2 #endif
309 gbeauche 1.1
310    
311     /*
312     * SIGSEGV handler initialization
313     */
314    
315     #if defined(HAVE_SIGINFO_T)
316     static bool sigsegv_do_install_handler(int sig)
317     {
318     // Setup SIGSEGV handler to process writes to frame buffer
319     #ifdef HAVE_SIGACTION
320     struct sigaction vosf_sa;
321     sigemptyset(&vosf_sa.sa_mask);
322     vosf_sa.sa_sigaction = sigsegv_handler;
323     vosf_sa.sa_flags = SA_SIGINFO;
324     return (sigaction(sig, &vosf_sa, 0) == 0);
325     #else
326     return (signal(sig, (signal_handler)sigsegv_handler) != SIG_ERR);
327     #endif
328     }
329 gbeauche 1.2 #endif
330    
331     #if defined(HAVE_SIGCONTEXT_SUBTERFUGE)
332 gbeauche 1.1 static bool sigsegv_do_install_handler(int sig)
333     {
334     // Setup SIGSEGV handler to process writes to frame buffer
335     #ifdef HAVE_SIGACTION
336     struct sigaction vosf_sa;
337     sigemptyset(&vosf_sa.sa_mask);
338     vosf_sa.sa_handler = (signal_handler)sigsegv_handler;
339     #if !EMULATED_68K && defined(__NetBSD__)
340     sigaddset(&vosf_sa.sa_mask, SIGALRM);
341     vosf_sa.sa_flags = SA_ONSTACK;
342     #else
343     vosf_sa.sa_flags = 0;
344     #endif
345     return (sigaction(sig, &vosf_sa, 0) == 0);
346     #else
347     return (signal(sig, (signal_handler)sigsegv_handler) != SIG_ERR);
348     #endif
349     }
350     #endif
351    
352     bool sigsegv_install_handler(sigsegv_handler_t handler)
353     {
354 gbeauche 1.2 #ifdef HAVE_SIGSEGV_RECOVERY
355 gbeauche 1.1 sigsegv_user_handler = handler;
356     bool success = true;
357     #define FAULT_HANDLER(sig) success = success && sigsegv_do_install_handler(sig);
358     SIGSEGV_ALL_SIGNALS
359     #undef FAULT_HANDLER
360     return success;
361     #else
362     // FAIL: no siginfo_t nor sigcontext subterfuge is available
363     return false;
364     #endif
365     }
366    
367    
368     /*
369     * SIGSEGV handler deinitialization
370     */
371    
372     void sigsegv_deinstall_handler(void)
373     {
374 gbeauche 1.2 #ifdef HAVE_SIGSEGV_RECOVERY
375 gbeauche 1.1 sigsegv_user_handler = 0;
376     #define FAULT_HANDLER(sig) signal(sig, SIG_DFL);
377     SIGSEGV_ALL_SIGNALS
378     #undef FAULT_HANDLER
379 gbeauche 1.2 #endif
380 gbeauche 1.1 }
381    
382     /*
383     * Test program used for configure/test
384     */
385    
386 gbeauche 1.4 #ifdef CONFIGURE_TEST_SIGSEGV_RECOVERY
387 gbeauche 1.1 #include <stdio.h>
388     #include <stdlib.h>
389     #include <fcntl.h>
390     #include <sys/mman.h>
391 gbeauche 1.4 #include "vm_alloc.h"
392 gbeauche 1.1
393     static int page_size;
394 gbeauche 1.3 static volatile char * page = 0;
395     static volatile int handler_called = 0;
396 gbeauche 1.1
397     static bool sigsegv_test_handler(sigsegv_address_t fault_address, sigsegv_address_t instruction_address)
398     {
399     handler_called++;
400     if ((fault_address - 123) != page)
401     exit(1);
402 gbeauche 1.4 if (vm_protect((char *)((unsigned long)fault_address & -page_size), page_size, VM_PAGE_READ | VM_PAGE_WRITE) != 0)
403 gbeauche 1.1 exit(1);
404     return true;
405     }
406    
407     int main(void)
408     {
409 gbeauche 1.4 if (vm_init() < 0)
410 gbeauche 1.1 return 1;
411    
412     page_size = getpagesize();
413 gbeauche 1.4 if ((page = (char *)vm_acquire(page_size)) == VM_MAP_FAILED)
414     return 1;
415    
416     if (vm_protect((char *)page, page_size, VM_PAGE_READ) < 0)
417 gbeauche 1.1 return 1;
418    
419     if (!sigsegv_install_handler(sigsegv_test_handler))
420     return 1;
421    
422     page[123] = 45;
423     page[123] = 45;
424    
425     if (handler_called != 1)
426     return 1;
427    
428 gbeauche 1.4 vm_exit();
429 gbeauche 1.1 return 0;
430     }
431     #endif