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root/cebix/BasiliskII/src/Unix/sigsegv.cpp
Revision: 1.4
Committed: 2001-06-26T22:35:41Z (23 years, 3 months ago) by gbeauche
Branch: MAIN
Changes since 1.3: +134 -9 lines
Log Message: 
- added SIGSEGV support for Linux/Alpha (to be checked), Darwin/PPC
- added uniform virtual memory allocation
  (supports mmap(), vm_allocate(), or fallbacks to malloc()/free())
- cleaned up memory allocation in main_unix.cpp

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     * Basilisk II (C) 1997-2001 Christian Bauer
8     *
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     #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, siginfo_t *sip, void *
58     #define SIGSEGV_FAULT_ADDRESS sip->si_addr
59     #endif
60    
61     #if HAVE_SIGCONTEXT_SUBTERFUGE
62     // Linux kernels prior to 2.4 ?
63     #if defined(__linux__)
64     #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
65     #if (defined(i386) || defined(__i386__))
66     #include <asm/sigcontext.h>
67     #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, struct sigcontext scs
68     #define SIGSEGV_FAULT_ADDRESS scs.cr2
69     #define SIGSEGV_FAULT_INSTRUCTION scs.eip
70     #endif
71     #if (defined(sparc) || defined(__sparc__))
72     #include <asm/sigcontext.h>
73 gbeauche 1.4 #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp, char* addr
74 gbeauche 1.1 #define SIGSEGV_FAULT_ADDRESS addr
75     #endif
76     #if (defined(powerpc) || defined(__powerpc__))
77     #include <asm/sigcontext.h>
78 gbeauche 1.4 #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, struct sigcontext *scp
79 gbeauche 1.1 #define SIGSEGV_FAULT_ADDRESS scp->regs->dar
80     #define SIGSEGV_FAULT_INSTRUCTION scp->regs->nip
81     #endif
82 gbeauche 1.4 #if (defined(alpha) || defined(__alpha__))
83     #include <asm/sigcontext.h>
84     #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
85     #define SIGSEGV_FAULT_ADDRESS get_fault_address(scp)
86     #define SIGSEGV_FAULT_INSTRUCTION scp->sc_pc
87    
88     // From Boehm's GC 6.0alpha8
89     static sigsegv_address_t get_fault_address(struct sigcontext *scp)
90     {
91     unsigned int instruction = *((unsigned int *)(scp->sc_pc));
92     unsigned long fault_address = scp->sc_regs[(instruction >> 16) & 0x1f];
93     fault_address += (signed long)(signed short)(instruction & 0xffff);
94     return (sigsegv_address_t)fault_address;
95     }
96     #endif
97 gbeauche 1.1 #endif
98    
99     // Irix 5 or 6 on MIPS
100     #if (defined(sgi) || defined(__sgi)) && (defined(SYSTYPE_SVR4) || defined(__SYSTYPE_SVR4))
101     #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
102     #define SIGSEGV_FAULT_ADDRESS scp->sc_badvaddr
103     #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
104     #endif
105    
106     // OSF/1 on Alpha
107     #if defined(__osf__)
108     #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
109     #define SIGSEGV_FAULT_ADDRESS scp->sc_traparg_a0
110     #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
111     #endif
112    
113     // AIX
114     #if defined(_AIX)
115     #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
116     #define SIGSEGV_FAULT_ADDRESS scp->sc_jmpbuf.jmp_context.o_vaddr
117     #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
118     #endif
119    
120     // NetBSD or FreeBSD
121     #if defined(__NetBSD__) || defined(__FreeBSD__)
122     #if (defined(m68k) || defined(__m68k__))
123     #include <m68k/frame.h>
124     #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
125     #define SIGSEGV_FAULT_ADDRESS ({ \
126     struct sigstate { \
127     int ss_flags; \
128     struct frame ss_frame; \
129     }; \
130     struct sigstate *state = (struct sigstate *)scp->sc_ap; \
131     char *fault_addr; \
132     switch (state->ss_frame.f_format) { \
133     case 7: /* 68040 access error */ \
134     /* "code" is sometimes unreliable (i.e. contains NULL or a bogus address), reason unknown */ \
135     fault_addr = state->ss_frame.f_fmt7.f_fa; \
136     break; \
137     default: \
138     fault_addr = (char *)code; \
139     break; \
140     } \
141     fault_addr; \
142     })
143     #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
144     #else
145     #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, void *scp, char *addr
146     #define SIGSEGV_FAULT_ADDRESS addr
147     #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGBUS)
148     #endif
149     #endif
150 gbeauche 1.4
151     // MacOS X
152     #if defined(__APPLE__) && defined(__MACH__)
153     #if (defined(ppc) || defined(__ppc__))
154     #define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
155     #define SIGSEGV_FAULT_ADDRESS get_fault_address(scp)
156     #define SIGSEGV_FAULT_INSTRUCTION scp->sc_ir
157     #define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGBUS)
158    
159     // From Boehm's GC 6.0alpha8
160     #define EXTRACT_OP1(iw) (((iw) & 0xFC000000) >> 26)
161     #define EXTRACT_OP2(iw) (((iw) & 0x000007FE) >> 1)
162     #define EXTRACT_REGA(iw) (((iw) & 0x001F0000) >> 16)
163     #define EXTRACT_REGB(iw) (((iw) & 0x03E00000) >> 21)
164     #define EXTRACT_REGC(iw) (((iw) & 0x0000F800) >> 11)
165     #define EXTRACT_DISP(iw) ((short *) &(iw))[1]
166    
167     static sigsegv_address_t get_fault_address(struct sigcontext *scp)
168     {
169     unsigned int instr = *((unsigned int *) scp->sc_ir);
170     unsigned int * regs = &((unsigned int *) scp->sc_regs)[2];
171     int disp = 0, tmp;
172     unsigned int baseA = 0, baseB = 0;
173     unsigned int addr, alignmask = 0xFFFFFFFF;
174    
175     switch(EXTRACT_OP1(instr)) {
176     case 38: /* stb */
177     case 39: /* stbu */
178     case 54: /* stfd */
179     case 55: /* stfdu */
180     case 52: /* stfs */
181     case 53: /* stfsu */
182     case 44: /* sth */
183     case 45: /* sthu */
184     case 47: /* stmw */
185     case 36: /* stw */
186     case 37: /* stwu */
187     tmp = EXTRACT_REGA(instr);
188     if(tmp > 0)
189     baseA = regs[tmp];
190     disp = EXTRACT_DISP(instr);
191     break;
192     case 31:
193     switch(EXTRACT_OP2(instr)) {
194     case 86: /* dcbf */
195     case 54: /* dcbst */
196     case 1014: /* dcbz */
197     case 247: /* stbux */
198     case 215: /* stbx */
199     case 759: /* stfdux */
200     case 727: /* stfdx */
201     case 983: /* stfiwx */
202     case 695: /* stfsux */
203     case 663: /* stfsx */
204     case 918: /* sthbrx */
205     case 439: /* sthux */
206     case 407: /* sthx */
207     case 661: /* stswx */
208     case 662: /* stwbrx */
209     case 150: /* stwcx. */
210     case 183: /* stwux */
211     case 151: /* stwx */
212     case 135: /* stvebx */
213     case 167: /* stvehx */
214     case 199: /* stvewx */
215     case 231: /* stvx */
216     case 487: /* stvxl */
217     tmp = EXTRACT_REGA(instr);
218     if(tmp > 0)
219     baseA = regs[tmp];
220     baseB = regs[EXTRACT_REGC(instr)];
221     /* determine Altivec alignment mask */
222     switch(EXTRACT_OP2(instr)) {
223     case 167: /* stvehx */
224     alignmask = 0xFFFFFFFE;
225     break;
226     case 199: /* stvewx */
227     alignmask = 0xFFFFFFFC;
228     break;
229     case 231: /* stvx */
230     alignmask = 0xFFFFFFF0;
231     break;
232     case 487: /* stvxl */
233     alignmask = 0xFFFFFFF0;
234     break;
235     }
236     break;
237     case 725: /* stswi */
238     tmp = EXTRACT_REGA(instr);
239     if(tmp > 0)
240     baseA = regs[tmp];
241     break;
242     default: /* ignore instruction */
243     return 0;
244     break;
245     }
246     break;
247     default: /* ignore instruction */
248     return 0;
249     break;
250     }
251    
252     addr = (baseA + baseB) + disp;
253     addr &= alignmask;
254     return (sigsegv_address_t)addr;
255     }
256     #endif
257     #endif
258 gbeauche 1.1 #endif
259    
260     // Fallbacks
261     #ifndef SIGSEGV_FAULT_INSTRUCTION
262     #define SIGSEGV_FAULT_INSTRUCTION SIGSEGV_INVALID_PC
263     #endif
264    
265 gbeauche 1.2 // SIGSEGV recovery supported ?
266     #if defined(SIGSEGV_ALL_SIGNALS) && defined(SIGSEGV_FAULT_HANDLER_ARGLIST) && defined(SIGSEGV_FAULT_ADDRESS)
267     #define HAVE_SIGSEGV_RECOVERY
268     #endif
269    
270 gbeauche 1.1
271     /*
272     * SIGSEGV global handler
273     */
274    
275 gbeauche 1.2 #ifdef HAVE_SIGSEGV_RECOVERY
276 gbeauche 1.1 static void sigsegv_handler(SIGSEGV_FAULT_HANDLER_ARGLIST)
277     {
278     // Call user's handler and reinstall the global handler, if required
279     if (sigsegv_user_handler((sigsegv_address_t)SIGSEGV_FAULT_ADDRESS, (sigsegv_address_t)SIGSEGV_FAULT_INSTRUCTION)) {
280     #if (defined(HAVE_SIGACTION) ? defined(SIGACTION_NEED_REINSTALL) : defined(SIGNAL_NEED_REINSTALL))
281     sigsegv_do_install_handler(sig);
282     #endif
283     }
284     else {
285     // FAIL: reinstall default handler for "safe" crash
286     #define FAULT_HANDLER(sig) signal(sig, SIG_DFL);
287     SIGSEGV_ALL_SIGNALS
288     #undef FAULT_HANDLER
289     }
290     }
291 gbeauche 1.2 #endif
292 gbeauche 1.1
293    
294     /*
295     * SIGSEGV handler initialization
296     */
297    
298     #if defined(HAVE_SIGINFO_T)
299     static bool sigsegv_do_install_handler(int sig)
300     {
301     // Setup SIGSEGV handler to process writes to frame buffer
302     #ifdef HAVE_SIGACTION
303     struct sigaction vosf_sa;
304     sigemptyset(&vosf_sa.sa_mask);
305     vosf_sa.sa_sigaction = sigsegv_handler;
306     vosf_sa.sa_flags = SA_SIGINFO;
307     return (sigaction(sig, &vosf_sa, 0) == 0);
308     #else
309     return (signal(sig, (signal_handler)sigsegv_handler) != SIG_ERR);
310     #endif
311     }
312 gbeauche 1.2 #endif
313    
314     #if defined(HAVE_SIGCONTEXT_SUBTERFUGE)
315 gbeauche 1.1 static bool sigsegv_do_install_handler(int sig)
316     {
317     // Setup SIGSEGV handler to process writes to frame buffer
318     #ifdef HAVE_SIGACTION
319     struct sigaction vosf_sa;
320     sigemptyset(&vosf_sa.sa_mask);
321     vosf_sa.sa_handler = (signal_handler)sigsegv_handler;
322     #if !EMULATED_68K && defined(__NetBSD__)
323     sigaddset(&vosf_sa.sa_mask, SIGALRM);
324     vosf_sa.sa_flags = SA_ONSTACK;
325     #else
326     vosf_sa.sa_flags = 0;
327     #endif
328     return (sigaction(sig, &vosf_sa, 0) == 0);
329     #else
330     return (signal(sig, (signal_handler)sigsegv_handler) != SIG_ERR);
331     #endif
332     }
333     #endif
334    
335     bool sigsegv_install_handler(sigsegv_handler_t handler)
336     {
337 gbeauche 1.2 #ifdef HAVE_SIGSEGV_RECOVERY
338 gbeauche 1.1 sigsegv_user_handler = handler;
339     bool success = true;
340     #define FAULT_HANDLER(sig) success = success && sigsegv_do_install_handler(sig);
341     SIGSEGV_ALL_SIGNALS
342     #undef FAULT_HANDLER
343     return success;
344     #else
345     // FAIL: no siginfo_t nor sigcontext subterfuge is available
346     return false;
347     #endif
348     }
349    
350    
351     /*
352     * SIGSEGV handler deinitialization
353     */
354    
355     void sigsegv_deinstall_handler(void)
356     {
357 gbeauche 1.2 #ifdef HAVE_SIGSEGV_RECOVERY
358 gbeauche 1.1 sigsegv_user_handler = 0;
359     #define FAULT_HANDLER(sig) signal(sig, SIG_DFL);
360     SIGSEGV_ALL_SIGNALS
361     #undef FAULT_HANDLER
362 gbeauche 1.2 #endif
363 gbeauche 1.1 }
364    
365     /*
366     * Test program used for configure/test
367     */
368    
369 gbeauche 1.4 #ifdef CONFIGURE_TEST_SIGSEGV_RECOVERY
370 gbeauche 1.1 #include <stdio.h>
371     #include <stdlib.h>
372     #include <fcntl.h>
373     #include <sys/mman.h>
374 gbeauche 1.4 #include "vm_alloc.h"
375 gbeauche 1.1
376     static int page_size;
377 gbeauche 1.3 static volatile char * page = 0;
378     static volatile int handler_called = 0;
379 gbeauche 1.1
380     static bool sigsegv_test_handler(sigsegv_address_t fault_address, sigsegv_address_t instruction_address)
381     {
382     handler_called++;
383     if ((fault_address - 123) != page)
384     exit(1);
385 gbeauche 1.4 if (vm_protect((char *)((unsigned long)fault_address & -page_size), page_size, VM_PAGE_READ | VM_PAGE_WRITE) != 0)
386 gbeauche 1.1 exit(1);
387     return true;
388     }
389    
390     int main(void)
391     {
392 gbeauche 1.4 if (vm_init() < 0)
393 gbeauche 1.1 return 1;
394    
395     page_size = getpagesize();
396 gbeauche 1.4 if ((page = (char *)vm_acquire(page_size)) == VM_MAP_FAILED)
397     return 1;
398    
399     if (vm_protect((char *)page, page_size, VM_PAGE_READ) < 0)
400 gbeauche 1.1 return 1;
401    
402     if (!sigsegv_install_handler(sigsegv_test_handler))
403     return 1;
404    
405     page[123] = 45;
406     page[123] = 45;
407    
408     if (handler_called != 1)
409     return 1;
410    
411 gbeauche 1.4 vm_exit();
412 gbeauche 1.1 return 0;
413     }
414     #endif