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 */
28 #include "interrupt.h"
30 #include "breakpoint.h"
33 extern char call_into_lisp_LRA[], call_into_lisp_end[];
35 extern size_t os_vm_page_size;
36 #define BREAKPOINT_INST 0x80
42 /* This must be called _after_ os_init(), so that we know what the
45 if (mmap((os_vm_address_t) call_into_lisp_LRA_page,os_vm_page_size,
46 OS_VM_PROT_ALL,MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED,-1,0)
47 == (os_vm_address_t) -1)
50 /* call_into_lisp_LRA is a collection of trampolines written in asm -
51 * see alpha-assem.S. We copy it to call_into_lisp_LRA_page where
52 * VOPs and things can find it. (I don't know why they can't find it
53 * where it was to start with.) */
54 bcopy(call_into_lisp_LRA,(void *)call_into_lisp_LRA_page,os_vm_page_size);
56 os_flush_icache((os_vm_address_t)call_into_lisp_LRA_page,
62 arch_get_bad_addr (int sig, siginfo_t *code, os_context_t *context)
66 /* Instructions are 32 bit quantities. */
68 /* fprintf(stderr,"arch_get_bad_addr %d %p %p\n",
69 sig, code, context); */
70 pc= (unsigned int *)(*os_context_pc_addr(context));
72 if (((unsigned long)pc) & 3) {
73 return NULL; /* In what case would pc be unaligned?? */
76 if ( (pc < READ_ONLY_SPACE_START ||
77 pc >= READ_ONLY_SPACE_START+READ_ONLY_SPACE_SIZE) &&
78 (pc < current_dynamic_space ||
79 pc >= current_dynamic_space + DYNAMIC_SPACE_SIZE))
82 return context->uc_mcontext.sc_traparg_a0;
86 arch_skip_instruction(os_context_t *context)
88 /* This may be complete rubbish, as (at least for traps) pc points
89 * _after_ the instruction that caused us to be here anyway.
91 ((char*)*os_context_pc_addr(context)) +=4; }
94 arch_internal_error_arguments(os_context_t *context)
96 return (unsigned char *)(*os_context_pc_addr(context)+4);
100 arch_pseudo_atomic_atomic(os_context_t *context)
102 return ((*os_context_register_addr(context,reg_ALLOC)) & 1);
105 void arch_set_pseudo_atomic_interrupted(os_context_t *context)
107 /* On coming out of an atomic section, we subtract 1 from
108 * reg_Alloc, then try to store something at that address. So,
109 * to signal that it was interrupted and a signal should be handled,
110 * we set bit 63 of reg_ALLOC here so that the end-of-atomic code
111 * will raise SIGSEGV (no ram mapped there). We catch the signal
112 * (see the appropriate *-os.c) and call interrupt_handle_pending()
113 * for the saved signal instead */
115 *os_context_register_addr(context,reg_ALLOC) |= (1L<<63);
118 void arch_clear_pseudo_atomic_interrupted(os_context_t *context)
120 *os_context_register_addr(context, reg_ALLOC) &= ~(1L<<63);
123 unsigned int arch_install_breakpoint(void *pc)
125 unsigned int *ptr = (unsigned int *)pc;
126 unsigned int result = *ptr;
127 *ptr = BREAKPOINT_INST;
129 os_flush_icache((os_vm_address_t)ptr, sizeof(unsigned int));
134 void arch_remove_breakpoint(void *pc, unsigned int orig_inst)
136 unsigned int *ptr = (unsigned int *)pc;
138 os_flush_icache((os_vm_address_t)pc, sizeof(unsigned int));
141 static unsigned int *skipped_break_addr, displaced_after_inst,
145 /* This returns a PC value. Lisp code is all in the 32-bit-addressable
146 * space, so we should be ok with an unsigned int. */
148 emulate_branch(os_context_t *context, unsigned int orig_inst)
150 int op = orig_inst >> 26;
151 int reg_a = (orig_inst >> 21) & 0x1f;
152 int reg_b = (orig_inst >> 16) & 0x1f;
154 (orig_inst&(1<<20)) ?
155 orig_inst | (-1 << 21) :
157 int next_pc = *os_context_pc_addr(context);
158 int branch = 0; /* was NULL; */
161 case 0x1a: /* jmp, jsr, jsr_coroutine, ret */
162 *os_context_register_addr(context,reg_a) =
163 *os_context_pc_addr(context);
164 *os_context_pc_addr(context) =
165 *os_context_register_addr(context,reg_b)& ~3;
168 *os_context_register_addr(context,reg_a)=*os_context_pc_addr(context);
171 case 0x31: /* fbeq */
172 if (*(os_context_float_register_addr(context,reg_a))==0) branch = 1;
174 case 0x32: /* fblt */
175 if (*os_context_float_register_addr(context,reg_a)<0) branch = 1;
177 case 0x33: /* fble */
178 if (*os_context_float_register_addr(context,reg_a)<=0) branch = 1;
181 *os_context_register_addr(context,reg_a)=*os_context_pc_addr(context);
184 case 0x35: /* fbne */
185 if (*os_context_register_addr(context,reg_a)!=0) branch = 1;
187 case 0x36: /* fbge */
188 if (*os_context_float_register_addr(context,reg_a)>=0) branch = 1;
190 case 0x37: /* fbgt */
191 if (*os_context_float_register_addr(context,reg_a)>0) branch = 1;
193 case 0x38: /* blbc */
194 if ((*os_context_register_addr(context,reg_a)&1) == 0) branch = 1;
197 if (*os_context_register_addr(context,reg_a)==0) branch = 1;
200 if (*os_context_register_addr(context,reg_a)<0) branch = 1;
203 if (*os_context_register_addr(context,reg_a)<=0) branch = 1;
205 case 0x3c: /* blbs */
206 if ((*os_context_register_addr(context,reg_a)&1)!=0) branch = 1;
209 if (*os_context_register_addr(context,reg_a)!=0) branch = 1;
212 if (*os_context_register_addr(context,reg_a)>=0) branch = 1;
215 if (*os_context_register_addr(context,reg_a)>0) branch = 1;
223 static sigset_t orig_sigmask;
225 /* Perform the instruction that we overwrote with a breakpoint. As we
226 * don't have a single-step facility, this means we have to:
227 * - put the instruction back
228 * - put a second breakpoint at the following instruction,
229 * set after_breakpoint and continue execution.
231 * When the second breakpoint is hit (very shortly thereafter, we hope)
232 * sigtrap_handler gets called again, but follows the AfterBreakpoint
234 * - puts a bpt back in the first breakpoint place (running across a
235 * breakpoint shouldn't cause it to be uninstalled)
236 * - replaces the second bpt with the instruction it was meant to be
242 void arch_do_displaced_inst(os_context_t *context,unsigned int orig_inst)
244 /* Apparent off-by-one errors ahoy. If you consult the Alpha ARM,
245 * it will tell you that after a BPT, the saved PC is the address
246 * of the instruction _after_ the instruction that caused the trap.
248 * However, we decremented PC by 4 before calling the Lisp-level
249 * handler that calls this routine (see alpha-arch.c line 322 and
250 * friends) so when we get to this point PC is actually pointing
251 * at the BPT instruction itself. This is good, because this is
252 * where we want to restart execution when we do that */
254 unsigned int *pc=(unsigned int *)(*os_context_pc_addr(context));
255 unsigned int *next_pc;
256 int op = orig_inst >> 26;;
258 orig_sigmask = *os_context_sigmask_addr(context);
259 sigaddset_blockable(os_context_sigmask_addr(context));
261 /* Put the original instruction back. */
263 os_flush_icache((os_vm_address_t)pc, sizeof(unsigned int));
264 skipped_break_addr = pc;
266 /* Figure out where we will end up after running the displaced
268 if (op == 0x1a || (op&0xf) == 0x30) /* a branch */
269 /* The cast to long is just to shut gcc up. */
270 next_pc = (unsigned int *)((long)emulate_branch(context,orig_inst));
274 /* Set the after breakpoint. */
275 displaced_after_inst = *next_pc;
276 *next_pc = BREAKPOINT_INST;
278 os_flush_icache((os_vm_address_t)next_pc, sizeof(unsigned int));
282 sigtrap_handler(int signal, siginfo_t *siginfo, os_context_t *context)
285 #ifdef LISP_FEATURE_LINUX
286 os_restore_fp_control(context);
289 /* this is different from how CMUCL does it. CMUCL used "call_pal
290 * PAL_gentrap", which doesn't do anything on Linux (unless NL0
291 * contains certain specific values). We use "bugchk" instead.
292 * It's (for our purposes) just the same as bpt but has a
293 * different opcode so we can test whether we're dealing with a
294 * breakpoint or a "system service" */
296 if ((*(unsigned int*)(*os_context_pc_addr(context)-4))==BREAKPOINT_INST) {
297 if (after_breakpoint) {
298 /* see comments above arch_do_displaced_inst. This is where
299 * we reinsert the breakpoint that we removed earlier */
301 *os_context_pc_addr(context) -=4;
302 *skipped_break_addr = BREAKPOINT_INST;
303 os_flush_icache((os_vm_address_t)skipped_break_addr,
304 sizeof(unsigned int));
305 skipped_break_addr = NULL;
306 *(unsigned int *)*os_context_pc_addr(context) =
307 displaced_after_inst;
308 os_flush_icache((os_vm_address_t)*os_context_pc_addr(context), sizeof(unsigned int));
309 *os_context_sigmask_addr(context)= orig_sigmask;
310 after_breakpoint=0; /* false */
313 code = trap_Breakpoint;
315 /* a "system service" */
316 code=*((u32 *)(*os_context_pc_addr(context)));
319 case trap_PendingInterrupt:
320 arch_skip_instruction(context);
321 interrupt_handle_pending(context);
325 fake_foreign_function_call(context);
326 lose("%%primitive halt called; the party is over.\n");
330 interrupt_internal_error(signal, siginfo, context, code==trap_Cerror);
333 case trap_Breakpoint: /* call lisp-level handler */
334 *os_context_pc_addr(context) -=4;
335 handle_breakpoint(signal, siginfo, context);
338 case trap_FunEndBreakpoint:
339 *os_context_pc_addr(context) -=4;
340 *os_context_pc_addr(context) =
341 (int)handle_fun_end_breakpoint(signal, siginfo, context);
345 fprintf(stderr, "unidentified breakpoint/trap %d\n",code);
346 interrupt_handle_now(signal, siginfo, context);
352 arch_get_fp_control()
354 return ieee_get_fp_control();
358 arch_set_fp_control(unsigned long fp)
360 ieee_set_fp_control(fp);
364 void arch_install_interrupt_handlers()
366 undoably_install_low_level_interrupt_handler(SIGTRAP, sigtrap_handler);
369 extern lispobj call_into_lisp(lispobj fun, lispobj *args, int nargs);
371 lispobj funcall0(lispobj function)
373 lispobj *args = current_control_stack_pointer;
375 return call_into_lisp(function, args, 0);
378 lispobj funcall1(lispobj function, lispobj arg0)
380 lispobj *args = current_control_stack_pointer;
382 current_control_stack_pointer += 1;
385 return call_into_lisp(function, args, 1);
388 lispobj funcall2(lispobj function, lispobj arg0, lispobj arg1)
390 lispobj *args = current_control_stack_pointer;
392 current_control_stack_pointer += 2;
396 return call_into_lisp(function, args, 2);
399 lispobj funcall3(lispobj function, lispobj arg0, lispobj arg1, lispobj arg2)
401 lispobj *args = current_control_stack_pointer;
403 current_control_stack_pointer += 3;
408 return call_into_lisp(function, args, 3);