2 * This software is part of the SBCL system. See the README file for
5 * This software is derived from the CMU CL system, which was
6 * written at Carnegie Mellon University and released into the
7 * public domain. The software is in the public domain and is
8 * provided with absolutely no warranty. See the COPYING and CREDITS
9 * files for more information.
12 /* Note that although superficially it appears that we use
13 * os_context_t like we ought to, we actually just assume its a
14 * ucontext in places. Naughty */
18 #include <asm/pal.h> /* for PAL_gentrap */
29 #include "interrupt.h"
31 #include "breakpoint.h"
34 extern char call_into_lisp_LRA[], call_into_lisp_end[];
35 extern size_t os_vm_page_size;
36 #define BREAKPOINT_INST 0x80
41 /* This must be called _after_ os_init, so we know what the page
43 if(mmap((os_vm_address_t) call_into_lisp_LRA_page,os_vm_page_size,
44 OS_VM_PROT_ALL,MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED,-1,0)
45 == (os_vm_address_t) -1)
48 /* call_into_lisp_LRA is a collection of trampolines written in asm -
49 * see alpha-assem.S. We copy it to call_into_lisp_LRA_page where
50 * VOPs and things can find it. (I don't know why they can't find it
51 * where it was to start with.) */
52 bcopy(call_into_lisp_LRA,(void *)call_into_lisp_LRA_page,os_vm_page_size);
54 os_flush_icache((os_vm_address_t)call_into_lisp_LRA_page,
60 arch_get_bad_addr (int sig, siginfo_t *code, os_context_t *context)
64 /* Instructions are 32 bit quantities. */
66 /* fprintf(stderr,"arch_get_bad_addr %d %p %p\n",
67 sig, code, context); */
68 pc= (unsigned int *)(*os_context_pc_addr(context));
70 if(((unsigned long)pc) & 3) {
71 return NULL; /* In what case would pc be unaligned?? */
74 if( (pc < READ_ONLY_SPACE_START ||
75 pc >= READ_ONLY_SPACE_START+READ_ONLY_SPACE_SIZE) &&
76 (pc < current_dynamic_space ||
77 pc >= current_dynamic_space + DYNAMIC_SPACE_SIZE))
82 if(((badinst>>27)!=0x16) /* STL or STQ */
83 && ((badinst>>27)!=0x13)) /* STS or STT */
84 return NULL; /* Otherwise forget about address. */
86 return (os_vm_address_t)
87 (*os_context_register_addr(context,((badinst>>16)&0x1f))
92 arch_skip_instruction(os_context_t *context)
94 /* This may be complete rubbish, as (at least for traps) pc points
95 * _after_ the instruction that caused us to be here anyway.
97 ((char*)*os_context_pc_addr(context)) +=4; }
100 arch_internal_error_arguments(os_context_t *context)
102 return (unsigned char *)(*os_context_pc_addr(context)+4);
106 arch_pseudo_atomic_atomic(os_context_t *context)
108 return ((*os_context_register_addr(context,reg_ALLOC)) & 1);
111 void arch_set_pseudo_atomic_interrupted(os_context_t *context)
113 /* On coming out of an atomic section, we subtract 1 from
114 * reg_Alloc, then try to store something at that address. On
115 * OSF/1 we add 1 to reg_Alloc here so that the end-of-atomic code
116 * will raise SIGTRAP for "unaligned access". Linux catches
117 * unaligned accesses in the kernel and fixes them up[1], so there
118 * we toggle bit 63 instead. The resulting address is somewhere
119 * out in no-man's land, so we get SIGSEGV when we try to access
120 * it. We catch whichever signal it is (see the appropriate
121 * *-os.c) and call interrupt_handle_pending() from it */
123 /* [1] This behaviour can be changed with osf_setsysinfo, but cmucl
127 *os_context_register_addr(context,reg_ALLOC) |= (1L<<63);
129 *os_context_register_addr(context,reg_ALLOC) |= 2;
133 /* XXX but is the caller of this storing all 64 bits? */
134 unsigned long arch_install_breakpoint(void *pc)
136 unsigned int *ptr = (unsigned int *)pc;
137 unsigned long result = (unsigned long) *ptr;
138 *ptr = BREAKPOINT_INST;
140 os_flush_icache((os_vm_address_t)ptr, sizeof(unsigned long));
145 void arch_remove_breakpoint(void *pc, unsigned long orig_inst)
147 /* was (unsigned int) but gcc complains. Changed to mirror
148 * install_breakpoint() above */
149 unsigned long *ptr=(unsigned long *)pc;
151 os_flush_icache((os_vm_address_t)pc, sizeof(unsigned long));
154 static unsigned int *skipped_break_addr, displaced_after_inst,
158 /* This returns a PC value. Lisp code is all in the 32-bit-addressable
159 * space, so we should be ok with an unsigned int. */
161 emulate_branch(os_context_t *context,unsigned long orig_inst)
163 int op = orig_inst >> 26;
164 int reg_a = (orig_inst >> 21) & 0x1f;
165 int reg_b = (orig_inst >> 16) & 0x1f;
167 (orig_inst&(1<<20)) ?
168 orig_inst | (-1 << 21) :
170 int next_pc = *os_context_pc_addr(context);
171 int branch = 0; /* was NULL; */
174 case 0x1a: /* jmp, jsr, jsr_coroutine, ret */
175 *os_context_register_addr(context,reg_a) =
176 *os_context_pc_addr(context);
177 *os_context_pc_addr(context) =
178 *os_context_register_addr(context,reg_b)& ~3;
181 *os_context_register_addr(context,reg_a)=*os_context_pc_addr(context);
184 case 0x31: /* fbeq */
185 if(*(os_context_fpregister_addr(context,reg_a))==0) branch = 1;
187 case 0x32: /* fblt */
188 if(*os_context_fpregister_addr(context,reg_a)<0) branch = 1;
190 case 0x33: /* fble */
191 if(*os_context_fpregister_addr(context,reg_a)<=0) branch = 1;
194 *os_context_register_addr(context,reg_a)=*os_context_pc_addr(context);
197 case 0x35: /* fbne */
198 if(*os_context_register_addr(context,reg_a)!=0) branch = 1;
200 case 0x36: /* fbge */
201 if(*os_context_fpregister_addr(context,reg_a)>=0) branch = 1;
203 case 0x37: /* fbgt */
204 if(*os_context_fpregister_addr(context,reg_a)>0) branch = 1;
206 case 0x38: /* blbc */
207 if((*os_context_register_addr(context,reg_a)&1) == 0) branch = 1;
210 if(*os_context_register_addr(context,reg_a)==0) branch = 1;
213 if(*os_context_register_addr(context,reg_a)<0) branch = 1;
216 if(*os_context_register_addr(context,reg_a)<=0) branch = 1;
218 case 0x3c: /* blbs */
219 if((*os_context_register_addr(context,reg_a)&1)!=0) branch = 1;
222 if(*os_context_register_addr(context,reg_a)!=0) branch = 1;
225 if(*os_context_register_addr(context,reg_a)>=0) branch = 1;
228 if(*os_context_register_addr(context,reg_a)>0) branch = 1;
236 static sigset_t orig_sigmask;
238 /* Perform the instruction that we overwrote with a breakpoint. As we
239 * don't have a single-step facility, this means we have to:
240 * - put the instruction back
241 * - put a second breakpoint at the following instruction,
242 * set after_breakpoint and continue execution.
244 * When the second breakpoint is hit (very shortly thereafter, we hope)
245 * sigtrap_handler gets called again, but follows the AfterBreakpoint
247 * - puts a bpt back in the first breakpoint place (running across a
248 * breakpoint shouldn't cause it to be uninstalled)
249 * - replaces the second bpt with the instruction it was meant to be
255 void arch_do_displaced_inst(os_context_t *context,unsigned int orig_inst)
257 /* Apparent off-by-one errors ahoy. If you consult the Alpha ARM,
258 * it will tell you that after a BPT, the saved PC is the address
259 * of the instruction _after_ the instruction that caused the trap.
261 * However, we decremented PC by 4 before calling the Lisp-level
262 * handler that calls this routine (see alpha-arch.c line 322 and
263 * friends) so when we get to this point PC is actually pointing
264 * at the BPT instruction itself. This is good, because this is
265 * where we want to restart execution when we do that */
267 unsigned int *pc=(unsigned int *)(*os_context_pc_addr(context));
268 unsigned int *next_pc;
269 int op = orig_inst >> 26;;
271 orig_sigmask = *os_context_sigmask_addr(context);
272 sigaddset_blockable(os_context_sigmask_addr(context));
274 /* Put the original instruction back. */
276 os_flush_icache((os_vm_address_t)pc, sizeof(unsigned long));
277 skipped_break_addr = pc;
279 /* Figure out where we will end up after running the displaced
281 if(op == 0x1a || (op&0xf) == 0x30) /* a branch */
282 /* The cast to long is just to shut gcc up. */
283 next_pc = (unsigned int *)((long)emulate_branch(context,orig_inst));
287 /* Set the after breakpoint. */
288 displaced_after_inst = *next_pc;
289 *next_pc = BREAKPOINT_INST;
291 os_flush_icache((os_vm_address_t)next_pc, sizeof(unsigned long));
295 sigtrap_handler(int signal, siginfo_t *siginfo, os_context_t *context)
299 /* Don't disallow recursive breakpoint traps. Otherwise, we can't */
300 /* use debugger breakpoints anywhere in here. */
301 sigset_t *mask=(os_context_sigmask_addr(context));
304 /* this is different from how CMUCL does it. CMUCL used "call_pal
305 * PAL_gentrap", which doesn't do anything on Linux (unless NL0
306 * contains certain specific values). We use "bugchk" instead.
307 * It's (for our purposes) just the same as bpt but has a
308 * different opcode so we can test whether we're dealing with a
309 * breakpoint or a "system service" */
311 if((*(unsigned int*)(*os_context_pc_addr(context)-4))== BREAKPOINT_INST) {
312 if(after_breakpoint) {
313 /* see comments above arch_do_displaced_inst. This is where
314 * we reinsert the breakpoint that we removed earlier */
316 *os_context_pc_addr(context) -=4;
317 *skipped_break_addr = BREAKPOINT_INST;
318 os_flush_icache((os_vm_address_t)skipped_break_addr,
319 sizeof(unsigned long));
320 skipped_break_addr = NULL;
321 *(unsigned int *)*os_context_pc_addr(context) =
322 displaced_after_inst;
323 os_flush_icache((os_vm_address_t)*os_context_pc_addr(context), sizeof(unsigned long));
324 *os_context_sigmask_addr(context)= orig_sigmask;
325 after_breakpoint=0; /* false */
328 code = trap_Breakpoint;
330 /* a "system service" */
331 code=*((u32 *)(*os_context_pc_addr(context)));
334 case trap_PendingInterrupt:
335 arch_skip_instruction(context);
336 interrupt_handle_pending(context);
340 fake_foreign_function_call(context);
341 lose("%%primitive halt called; the party is over.\n");
345 interrupt_internal_error(signal, siginfo, context, code==trap_Cerror);
348 case trap_Breakpoint: /* call lisp-level handler */
349 *os_context_pc_addr(context) -=4;
350 handle_breakpoint(signal, siginfo, context);
353 case trap_FunEndBreakpoint:
354 *os_context_pc_addr(context) -=4;
355 *os_context_pc_addr(context) =
356 (int)handle_fun_end_breakpoint(signal, siginfo, context);
360 fprintf(stderr, "unidetified breakpoint/trap %d\n",code);
361 interrupt_handle_now(signal, siginfo, context);
366 static void sigfpe_handler(int signal, int code, os_context_t *context)
368 /* what should this contain? interesting question. If it really
369 * is empty, why don't we just ignore the signal? -dan 2001.08.10
373 void arch_install_interrupt_handlers()
375 undoably_install_low_level_interrupt_handler(SIGTRAP, sigtrap_handler);
376 undoably_install_low_level_interrupt_handler(SIGFPE, sigfpe_handler);
379 extern lispobj call_into_lisp(lispobj fun, lispobj *args, int nargs);
381 lispobj funcall0(lispobj function)
383 lispobj *args = current_control_stack_pointer;
385 return call_into_lisp(function, args, 0);
388 lispobj funcall1(lispobj function, lispobj arg0)
390 lispobj *args = current_control_stack_pointer;
392 current_control_stack_pointer += 1;
395 return call_into_lisp(function, args, 1);
398 lispobj funcall2(lispobj function, lispobj arg0, lispobj arg1)
400 lispobj *args = current_control_stack_pointer;
402 current_control_stack_pointer += 2;
406 return call_into_lisp(function, args, 2);
409 lispobj funcall3(lispobj function, lispobj arg0, lispobj arg1, lispobj arg2)
411 lispobj *args = current_control_stack_pointer;
413 current_control_stack_pointer += 3;
418 return call_into_lisp(function, args, 3);