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.
23 #include "interrupt.h"
25 #include "breakpoint.h"
27 #define BREAKPOINT_INST 0xcc /* INT3 */
29 unsigned long fast_random_state = 1;
35 * hacking signal contexts
37 * (This depends both on architecture, which determines what we might
38 * want to get to, and on OS, which determines how we get to it.)
42 context_eflags_addr(os_context_t *context)
45 /* KLUDGE: As of kernel 2.2.14 on Red Hat 6.2, there's code in the
46 * <sys/ucontext.h> file to define symbolic names for offsets into
47 * gregs[], but it's conditional on __USE_GNU and not defined, so
48 * we need to do this nasty absolute index magic number thing
50 return &context->uc_mcontext.gregs[16];
51 #elif defined __FreeBSD__
52 return &context->uc_mcontext.mc_eflags;
53 #elif defined __OpenBSD__
54 return &context->sc_eflags;
60 void arch_skip_instruction(os_context_t *context)
62 /* Assuming we get here via an INT3 xxx instruction, the PC now
63 * points to the interrupt code (a Lisp value) so we just move
64 * past it. Skip the code; after that, if the code is an
65 * error-trap or cerror-trap then skip the data bytes that follow. */
70 FSHOW((stderr, "[arch_skip_inst at %x]\n", *os_context_pc_addr(context)));
72 /* Get and skip the Lisp interrupt code. */
73 code = *(char*)(*os_context_pc_addr(context))++;
78 /* Lisp error arg vector length */
79 vlen = *(char*)(*os_context_pc_addr(context))++;
80 /* Skip Lisp error arg data bytes. */
82 ( (char*)(*os_context_pc_addr(context)) )++;
86 case trap_Breakpoint: /* not tested */
87 case trap_FunctionEndBreakpoint: /* not tested */
90 case trap_PendingInterrupt:
92 /* only needed to skip the Code */
96 fprintf(stderr,"[arch_skip_inst invalid code %d\n]\n",code);
101 "[arch_skip_inst resuming at %x]\n",
102 *os_context_pc_addr(context)));
106 arch_internal_error_arguments(os_context_t *context)
108 return 1 + (unsigned char *)(*os_context_pc_addr(context));
112 arch_pseudo_atomic_atomic(os_context_t *context)
114 return SymbolValue(PSEUDO_ATOMIC_ATOMIC);
118 arch_set_pseudo_atomic_interrupted(os_context_t *context)
120 SetSymbolValue(PSEUDO_ATOMIC_INTERRUPTED, make_fixnum(1));
124 * This stuff seems to get called for TRACE and debug activity.
128 arch_install_breakpoint(void *pc)
130 unsigned long result = *(unsigned long*)pc;
132 *(char*)pc = BREAKPOINT_INST; /* x86 INT3 */
133 *((char*)pc+1) = trap_Breakpoint; /* Lisp trap code */
139 arch_remove_breakpoint(void *pc, unsigned long orig_inst)
141 *((char *)pc) = orig_inst & 0xff;
142 *((char *)pc + 1) = (orig_inst & 0xff00) >> 8;
145 /* When single stepping, single_stepping holds the original instruction
147 unsigned int *single_stepping = NULL;
148 #ifdef CANNOT_GET_TO_SINGLE_STEP_FLAG
149 unsigned int single_step_save1;
150 unsigned int single_step_save2;
151 unsigned int single_step_save3;
155 arch_do_displaced_inst(os_context_t *context, unsigned long orig_inst)
157 unsigned int *pc = (unsigned int*)(*os_context_pc_addr(context));
159 /* Put the original instruction back. */
160 *((char *)pc) = orig_inst & 0xff;
161 *((char *)pc + 1) = (orig_inst & 0xff00) >> 8;
163 #ifdef CANNOT_GET_TO_SINGLE_STEP_FLAG
164 /* Install helper instructions for the single step:
165 * pushf; or [esp],0x100; popf. */
166 single_step_save1 = *(pc-3);
167 single_step_save2 = *(pc-2);
168 single_step_save3 = *(pc-1);
169 *(pc-3) = 0x9c909090;
170 *(pc-2) = 0x00240c81;
171 *(pc-1) = 0x9d000001;
173 *context_eflags_addr(context) |= 0x100;
176 single_stepping = (unsigned int*)pc;
178 #ifdef CANNOT_GET_TO_SINGLE_STEP_FLAG
179 *os_context_pc_addr(context) = (char *)pc - 9;
184 sigtrap_handler(int signal, siginfo_t *info, void *void_context)
186 int code = info->si_code;
187 os_context_t *context = (os_context_t*)void_context;
190 if (single_stepping && (signal==SIGTRAP))
192 /* fprintf(stderr,"* single step trap %x\n", single_stepping); */
194 #ifdef CANNOT_GET_TO_SINGLE_STEP_FLAG
195 /* Un-install single step helper instructions. */
196 *(single_stepping-3) = single_step_save1;
197 *(single_stepping-2) = single_step_save2;
198 *(single_stepping-1) = single_step_save3;
200 *context_eflags_addr(context) ^= 0x100;
202 /* Re-install the breakpoint if possible. */
203 if (*os_context_pc_addr(context) == (int)single_stepping + 1) {
204 fprintf(stderr, "warning: couldn't reinstall breakpoint\n");
206 *((char *)single_stepping) = BREAKPOINT_INST; /* x86 INT3 */
207 *((char *)single_stepping+1) = trap_Breakpoint;
210 single_stepping = NULL;
214 /* This is just for info in case the monitor wants to print an
216 current_control_stack_pointer =
217 (lispobj *)*os_context_sp_addr(context);
219 /* On entry %eip points just after the INT3 byte and aims at the
220 * 'kind' value (eg trap_Cerror). For error-trap and Cerror-trap a
221 * number of bytes will follow, the first is the length of the byte
222 * arguments to follow. */
223 trap = *(unsigned char *)(*os_context_pc_addr(context));
226 case trap_PendingInterrupt:
227 FSHOW((stderr, "<trap pending interrupt>\n"));
228 arch_skip_instruction(context);
229 interrupt_handle_pending(context);
233 /* Note: the old CMU CL code tried to save FPU state
234 * here, and restore it after we do our thing, but there
235 * seems to be no point in doing that, since we're just
236 * going to lose(..) anyway. */
237 fake_foreign_function_call(context);
238 lose("%%PRIMITIVE HALT called; the party is over.");
242 FSHOW((stderr, "<trap error/cerror %d>\n", code));
243 interrupt_internal_error(signal, info, context, code==trap_Cerror);
246 case trap_Breakpoint:
247 (char*)(*os_context_pc_addr(context)) -= 1;
248 handle_breakpoint(signal, info, context);
251 case trap_FunctionEndBreakpoint:
252 (char*)(*os_context_pc_addr(context)) -= 1;
253 *os_context_pc_addr(context) =
254 (int)handle_function_end_breakpoint(signal, info, context);
258 FSHOW((stderr,"[C--trap default %d %d %x]\n",
259 signal, code, context));
260 interrupt_handle_now(signal, info, context);
266 arch_install_interrupt_handlers()
268 interrupt_install_low_level_handler(SIGILL , sigtrap_handler);
269 interrupt_install_low_level_handler(SIGTRAP, sigtrap_handler);
272 /* This is implemented in assembly language and called from C: */
274 call_into_lisp(lispobj fun, lispobj *args, int nargs);
276 /* These functions are an interface to the Lisp call-in facility.
277 * Since this is C we can know nothing about the calling environment.
278 * The control stack might be the C stack if called from the monitor
279 * or the Lisp stack if called as a result of an interrupt or maybe
280 * even a separate stack. The args are most likely on that stack but
281 * could be in registers depending on what the compiler likes. So we
282 * copy the args into a portable vector and let the assembly language
283 * call-in function figure it out. */
285 funcall0(lispobj function)
287 lispobj *args = NULL;
289 return call_into_lisp(function, args, 0);
292 funcall1(lispobj function, lispobj arg0)
296 return call_into_lisp(function, args, 1);
299 funcall2(lispobj function, lispobj arg0, lispobj arg1)
304 return call_into_lisp(function, args, 2);
307 funcall3(lispobj function, lispobj arg0, lispobj arg1, lispobj arg2)
313 return call_into_lisp(function, args, 3);