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.
27 #include "interrupt.h"
29 #include "breakpoint.h"
31 #define BREAKPOINT_INST 0xcc /* INT3 */
33 unsigned long fast_random_state = 1;
39 * hacking signal contexts
41 * (This depends both on architecture, which determines what we might
42 * want to get to, and on OS, which determines how we get to it.)
46 context_eflags_addr(os_context_t *context)
49 /* KLUDGE: As of kernel 2.2.14 on Red Hat 6.2, there's code in the
50 * <sys/ucontext.h> file to define symbolic names for offsets into
51 * gregs[], but it's conditional on __USE_GNU and not defined, so
52 * we need to do this nasty absolute index magic number thing
54 return &context->uc_mcontext.gregs[16];
55 #elif defined __FreeBSD__
56 return &context->uc_mcontext.mc_eflags;
57 #elif defined __OpenBSD__
58 return &context->sc_eflags;
64 void arch_skip_instruction(os_context_t *context)
66 /* Assuming we get here via an INT3 xxx instruction, the PC now
67 * points to the interrupt code (a Lisp value) so we just move
68 * past it. Skip the code; after that, if the code is an
69 * error-trap or cerror-trap then skip the data bytes that follow. */
74 FSHOW((stderr, "[arch_skip_inst at %x]\n", *os_context_pc_addr(context)));
76 /* Get and skip the Lisp interrupt code. */
77 code = *(char*)(*os_context_pc_addr(context))++;
82 /* Lisp error arg vector length */
83 vlen = *(char*)(*os_context_pc_addr(context))++;
84 /* Skip Lisp error arg data bytes. */
86 (char*)(*os_context_pc_addr(context))++;
90 case trap_Breakpoint: /* not tested */
91 case trap_FunctionEndBreakpoint: /* not tested */
94 case trap_PendingInterrupt:
96 /* only needed to skip the Code */
100 fprintf(stderr,"[arch_skip_inst invalid code %d\n]\n",code);
105 "[arch_skip_inst resuming at %x]\n",
106 *os_context_pc_addr(context)));
110 arch_internal_error_arguments(os_context_t *context)
112 return 1 + (unsigned char *)(*os_context_pc_addr(context));
116 arch_pseudo_atomic_atomic(os_context_t *context)
118 return SymbolValue(PSEUDO_ATOMIC_ATOMIC);
122 arch_set_pseudo_atomic_interrupted(os_context_t *context)
124 SetSymbolValue(PSEUDO_ATOMIC_INTERRUPTED, make_fixnum(1));
128 * This stuff seems to get called for TRACE and debug activity.
132 arch_install_breakpoint(void *pc)
134 unsigned long result = *(unsigned long*)pc;
136 *(char*)pc = BREAKPOINT_INST; /* x86 INT3 */
137 *((char*)pc+1) = trap_Breakpoint; /* Lisp trap code */
143 arch_remove_breakpoint(void *pc, unsigned long orig_inst)
145 *((char *)pc) = orig_inst & 0xff;
146 *((char *)pc + 1) = (orig_inst & 0xff00) >> 8;
149 /* When single stepping, single_stepping holds the original instruction
151 unsigned int *single_stepping=NULL;
153 unsigned int single_step_save1;
154 unsigned int single_step_save2;
155 unsigned int single_step_save3;
159 arch_do_displaced_inst(os_context_t *context, unsigned long orig_inst)
161 unsigned int *pc = (unsigned int*)(*os_context_pc_addr(context));
163 /* Put the original instruction back. */
164 *((char *)pc) = orig_inst & 0xff;
165 *((char *)pc + 1) = (orig_inst & 0xff00) >> 8;
168 *context_eflags_addr(context) |= 0x100;
170 /* Install helper instructions for the single step:
171 * pushf; or [esp],0x100; popf. */
172 single_step_save1 = *(pc-3);
173 single_step_save2 = *(pc-2);
174 single_step_save3 = *(pc-1);
175 *(pc-3) = 0x9c909090;
176 *(pc-2) = 0x00240c81;
177 *(pc-1) = 0x9d000001;
180 single_stepping = (unsigned int*)pc;
183 *os_context_pc_addr(context) = (char *)pc - 9;
188 sigtrap_handler(int signal, siginfo_t *info, void *void_context)
190 int code = info->si_code;
191 os_context_t *context = (os_context_t*)void_context;
194 SHOW("entering sigtrap_handler(..)"); /* REMOVEME */
196 if (single_stepping && (signal==SIGTRAP))
198 /* fprintf(stderr,"* single step trap %x\n", single_stepping); */
201 /* Un-install single step helper instructions. */
202 *(single_stepping-3) = single_step_save1;
203 *(single_stepping-2) = single_step_save2;
204 *(single_stepping-1) = single_step_save3;
206 *context_eflags_addr(context) ^= 0x100;
208 /* Re-install the breakpoint if possible. */
209 if (*os_context_pc_addr(context) == (int)single_stepping + 1) {
210 fprintf(stderr, "warning: couldn't reinstall breakpoint\n");
212 char *ptr = (char*)single_stepping;
213 *((char *)single_stepping) = BREAKPOINT_INST; /* x86 INT3 */
214 *((char *)single_stepping+1) = trap_Breakpoint;
217 single_stepping = NULL;
221 /* This is just for info in case the monitor wants to print an
223 current_control_stack_pointer =
224 (lispobj*)*os_context_sp_addr(context);
226 /* On entry %eip points just after the INT3 byte and aims at the
227 * 'kind' value (eg trap_Cerror). For error-trap and Cerror-trap a
228 * number of bytes will follow, the first is the length of the byte
229 * arguments to follow. */
230 trap = *(unsigned char *)(*os_context_pc_addr(context));
233 case trap_PendingInterrupt:
234 FSHOW((stderr, "<trap pending interrupt>\n"));
235 arch_skip_instruction(context);
236 interrupt_handle_pending(context);
240 /* Note: the old CMU CL code tried to save FPU state
241 * here, and restore it after we do our thing, but there
242 * seems to be no point in doing that, since we're just
243 * going to lose(..) anyway. */
244 SHOW("in trap_Halt case of sigtrap_handler(..)"); /* REMOVEME */
245 fake_foreign_function_call(context);
246 lose("%%primitive halt called; the party is over.");
250 FSHOW((stderr, "<trap error/cerror %d>\n", code));
251 interrupt_internal_error(signal, info, context, code==trap_Cerror);
254 case trap_Breakpoint:
255 (char*)(*os_context_pc_addr(context)) -= 1;
256 handle_breakpoint(signal, info, context);
259 case trap_FunctionEndBreakpoint:
260 (char*)(*os_context_pc_addr(context)) -= 1;
261 *os_context_pc_addr(context) =
262 (int)handle_function_end_breakpoint(signal, info, context);
266 FSHOW((stderr,"[C--trap default %d %d %x]\n",
267 signal, code, context));
268 interrupt_handle_now(signal, info, context);
271 SHOW("leaving sigtrap_handler(..)"); /* REMOVEME */
275 arch_install_interrupt_handlers()
277 interrupt_install_low_level_handler(SIGILL , sigtrap_handler);
278 interrupt_install_low_level_handler(SIGTRAP, sigtrap_handler);
281 /* This is implemented in assembly language and called from C: */
283 call_into_lisp(lispobj fun, lispobj *args, int nargs);
285 /* These functions are an interface to the Lisp call-in facility.
286 * Since this is C we can know nothing about the calling environment.
287 * The control stack might be the C stack if called from the monitor
288 * or the Lisp stack if called as a result of an interrupt or maybe
289 * even a separate stack. The args are most likely on that stack but
290 * could be in registers depending on what the compiler likes. So we
291 * copy the args into a portable vector and let the assembly language
292 * call-in function figure it out. */
294 funcall0(lispobj function)
296 lispobj *args = NULL;
298 return call_into_lisp(function, args, 0);
301 funcall1(lispobj function, lispobj arg0)
305 return call_into_lisp(function, args, 1);
308 funcall2(lispobj function, lispobj arg0, lispobj arg1)
313 return call_into_lisp(function, args, 2);
316 funcall3(lispobj function, lispobj arg0, lispobj arg1, lispobj arg2)
322 return call_into_lisp(function, args, 3);