2 * exceptions-mips.c: exception support for MIPS
5 * Mark Mason (mason@broadcom.com)
7 * Based on exceptions-ppc.c by:
8 * Dietmar Maurer (dietmar@ximian.com)
9 * Paolo Molaro (lupus@ximian.com)
12 * (C) 2001 Ximian, Inc.
20 #include <mono/arch/mips/mips-codegen.h>
21 #include <mono/metadata/appdomain.h>
22 #include <mono/metadata/tabledefs.h>
23 #include <mono/metadata/threads.h>
24 #include <mono/metadata/debug-helpers.h>
25 #include <mono/metadata/exception.h>
26 #include <mono/metadata/mono-debug.h>
29 #include "mini-mips.h"
31 #define GENERIC_EXCEPTION_SIZE 256
34 * mono_arch_get_restore_context:
36 * Returns a pointer to a method which restores a previously saved MonoContext.
37 * The first argument in a0 is the pointer to the MonoContext.
40 mono_arch_get_restore_context (MonoTrampInfo **info, gboolean aot)
44 static guint8 start [512];
45 static int inited = 0;
46 guint32 iregs_to_restore;
57 mips_move (code, mips_at, mips_a0);
59 iregs_to_restore = (MONO_ARCH_CALLEE_SAVED_REGS \
60 | (1 << mips_sp) | (1 << mips_ra));
61 for (i = 0; i < MONO_SAVED_GREGS; ++i) {
62 //if (iregs_to_restore & (1 << i)) {
63 if (i != mips_zero && i != mips_at) {
64 MIPS_LW (code, i, mips_at, G_STRUCT_OFFSET (MonoContext, sc_regs[i]));
68 /* Get the address to return to */
69 mips_lw (code, mips_t9, mips_at, G_STRUCT_OFFSET (MonoContext, sc_pc));
71 /* jump to the saved IP */
72 mips_jr (code, mips_t9);
76 mips_break (code, 0xff);
78 g_assert ((code - start) < sizeof(start));
79 mono_arch_flush_icache (start, code - start);
80 mono_profiler_code_buffer_new (start, code - start, MONO_PROFILER_CODE_BUFFER_EXCEPTION_HANDLING, NULL);
85 * mono_arch_get_call_filter:
87 * Returns a pointer to a method which calls an exception filter. We
88 * also use this function to call finally handlers (we pass NULL as
89 * @exc object in this case).
91 * This function is invoked as
92 * call_handler (MonoContext *ctx, handler)
94 * Where 'handler' is a function to be invoked as:
98 mono_arch_get_call_filter (MonoTrampInfo **info, gboolean aot)
100 static guint8 start [320];
101 static int inited = 0;
117 g_assert ((alloc_size & (MIPS_STACK_ALIGNMENT-1)) == 0);
119 mips_addiu (code, mips_sp, mips_sp, -alloc_size);
120 mips_sw (code, mips_ra, mips_sp, alloc_size + MIPS_RET_ADDR_OFFSET);
122 /* Save global registers on stack (s0 - s7) */
124 MIPS_SW (code, mips_s0, mips_sp, offset); offset += IREG_SIZE;
125 MIPS_SW (code, mips_s1, mips_sp, offset); offset += IREG_SIZE;
126 MIPS_SW (code, mips_s2, mips_sp, offset); offset += IREG_SIZE;
127 MIPS_SW (code, mips_s3, mips_sp, offset); offset += IREG_SIZE;
128 MIPS_SW (code, mips_s4, mips_sp, offset); offset += IREG_SIZE;
129 MIPS_SW (code, mips_s5, mips_sp, offset); offset += IREG_SIZE;
130 MIPS_SW (code, mips_s6, mips_sp, offset); offset += IREG_SIZE;
131 MIPS_SW (code, mips_s7, mips_sp, offset); offset += IREG_SIZE;
132 MIPS_SW (code, mips_fp, mips_sp, offset); offset += IREG_SIZE;
134 /* Restore global registers from MonoContext, including the frame pointer */
135 MIPS_LW (code, mips_s0, mips_a0, G_STRUCT_OFFSET (MonoContext, sc_regs[mips_s0]));
136 MIPS_LW (code, mips_s1, mips_a0, G_STRUCT_OFFSET (MonoContext, sc_regs[mips_s1]));
137 MIPS_LW (code, mips_s2, mips_a0, G_STRUCT_OFFSET (MonoContext, sc_regs[mips_s2]));
138 MIPS_LW (code, mips_s3, mips_a0, G_STRUCT_OFFSET (MonoContext, sc_regs[mips_s3]));
139 MIPS_LW (code, mips_s4, mips_a0, G_STRUCT_OFFSET (MonoContext, sc_regs[mips_s4]));
140 MIPS_LW (code, mips_s5, mips_a0, G_STRUCT_OFFSET (MonoContext, sc_regs[mips_s5]));
141 MIPS_LW (code, mips_s6, mips_a0, G_STRUCT_OFFSET (MonoContext, sc_regs[mips_s6]));
142 MIPS_LW (code, mips_s7, mips_a0, G_STRUCT_OFFSET (MonoContext, sc_regs[mips_s7]));
143 MIPS_LW (code, mips_fp, mips_a0, G_STRUCT_OFFSET (MonoContext, sc_regs[mips_fp]));
145 /* a1 is the handler to call */
146 mips_move (code, mips_t9, mips_a1);
148 /* jump to the saved IP */
149 mips_jalr (code, mips_t9, mips_ra);
152 /* restore all regs from the stack */
154 MIPS_LW (code, mips_s0, mips_sp, offset); offset += IREG_SIZE;
155 MIPS_LW (code, mips_s1, mips_sp, offset); offset += IREG_SIZE;
156 MIPS_LW (code, mips_s2, mips_sp, offset); offset += IREG_SIZE;
157 MIPS_LW (code, mips_s3, mips_sp, offset); offset += IREG_SIZE;
158 MIPS_LW (code, mips_s4, mips_sp, offset); offset += IREG_SIZE;
159 MIPS_LW (code, mips_s5, mips_sp, offset); offset += IREG_SIZE;
160 MIPS_LW (code, mips_s6, mips_sp, offset); offset += IREG_SIZE;
161 MIPS_LW (code, mips_s7, mips_sp, offset); offset += IREG_SIZE;
162 MIPS_LW (code, mips_fp, mips_sp, offset); offset += IREG_SIZE;
165 mips_lw (code, mips_ra, mips_sp, alloc_size + MIPS_RET_ADDR_OFFSET);
166 mips_addiu (code, mips_sp, mips_sp, alloc_size);
167 mips_jr (code, mips_ra);
170 g_assert ((code - start) < sizeof(start));
171 mono_arch_flush_icache (start, code - start);
172 mono_profiler_code_buffer_new (start, code - start, MONO_PROFILER_CODE_BUFFER_EXCEPTION_HANDLING, NULL);
177 throw_exception (MonoObject *exc, unsigned long eip, unsigned long esp, gboolean rethrow)
181 #ifdef DEBUG_EXCEPTIONS
182 g_print ("throw_exception: exc=%p eip=%p esp=%p rethrow=%d\n",
183 exc, (void *)eip, (void *) esp, rethrow);
186 /* adjust eip so that it point into the call instruction */
189 memset (&ctx, 0, sizeof (MonoContext));
191 /*g_print ("stack in throw: %p\n", esp);*/
192 memcpy (&ctx.sc_regs, (void *)(esp + MIPS_STACK_PARAM_OFFSET),
193 sizeof (gulong) * MONO_SAVED_GREGS);
194 memset (&ctx.sc_fpregs, 0, sizeof (mips_freg) * MONO_SAVED_FREGS);
195 MONO_CONTEXT_SET_IP (&ctx, eip);
197 if (mono_object_isinst (exc, mono_defaults.exception_class)) {
198 MonoException *mono_ex = (MonoException*)exc;
200 mono_ex->stack_trace = NULL;
202 mono_handle_exception (&ctx, exc);
203 #ifdef DEBUG_EXCEPTIONS
204 g_print ("throw_exception: restore to pc=%p sp=%p fp=%p ctx=%p\n",
205 (void *) ctx.sc_pc, (void *) ctx.sc_regs[mips_sp],
206 (void *) ctx.sc_regs[mips_fp], &ctx);
208 mono_restore_context (&ctx);
210 g_assert_not_reached ();
214 * arch_get_throw_exception_generic:
216 * Returns a function pointer which can be used to raise
217 * exceptions. The returned function has the following
218 * signature: void (*func) (MonoException *exc); or
219 * void (*func) (char *exc_name);
223 mono_arch_get_throw_exception_generic (guint8 *start, int size, int corlib, gboolean rethrow)
226 int alloc_size, pos, i;
230 //g_print ("mono_arch_get_throw_exception_generic: code=%p\n", code);
233 /* XXX - save all the FP regs on the stack ? */
235 pos += MONO_MAX_IREGS * sizeof(guint32);
237 alloc_size = MIPS_MINIMAL_STACK_SIZE + pos + 64;
238 // align to MIPS_STACK_ALIGNMENT bytes
239 alloc_size += MIPS_STACK_ALIGNMENT - 1;
240 alloc_size &= ~(MIPS_STACK_ALIGNMENT - 1);
242 g_assert ((alloc_size & (MIPS_STACK_ALIGNMENT-1)) == 0);
243 mips_addiu (code, mips_sp, mips_sp, -alloc_size);
244 mips_sw (code, mips_ra, mips_sp, alloc_size + MIPS_RET_ADDR_OFFSET);
246 /* Save all the regs on the stack */
247 for (i = 0; i < MONO_MAX_IREGS; i++) {
249 MIPS_SW (code, i, mips_sp, i*IREG_SIZE + MIPS_STACK_PARAM_OFFSET);
251 mips_addiu (code, mips_at, mips_sp, alloc_size);
252 MIPS_SW (code, mips_at, mips_sp, i*IREG_SIZE + MIPS_STACK_PARAM_OFFSET);
257 mips_move (code, mips_a1, mips_a0);
258 mips_load (code, mips_a0, mono_defaults.corlib);
259 mips_load (code, mips_t9, mono_exception_from_token);
260 mips_jalr (code, mips_t9, mips_ra);
262 mips_move (code, mips_a0, mips_v0);
264 /* call throw_exception (exc, ip, sp, rethrow) */
266 /* exc is already in place in a0 */
270 mips_lw (code, mips_a1, mips_sp, alloc_size + MIPS_RET_ADDR_OFFSET);
272 mips_move (code, mips_a1, mips_ra);
274 /* current sp & rethrow */
275 mips_move (code, mips_a2, mips_sp);
276 mips_addiu (code, mips_a3, mips_zero, rethrow);
278 mips_load (code, mips_t9, throw_exception);
279 mips_jr (code, mips_t9);
281 /* we should never reach this breakpoint */
282 mips_break (code, 0xfe);
284 g_assert ((code - start) < size);
285 mono_arch_flush_icache (start, code - start);
286 mono_profiler_code_buffer_new (start, code - start, MONO_PROFILER_CODE_BUFFER_EXCEPTION_HANDLING, NULL);
291 * mono_arch_get_rethrow_exception:
293 * Returns a function pointer which can be used to rethrow
294 * exceptions. The returned function has the following
295 * signature: void (*func) (MonoException *exc);
299 mono_arch_get_rethrow_exception (MonoTrampInfo **info, gboolean aot)
301 static guint8 start [GENERIC_EXCEPTION_SIZE];
302 static int inited = 0;
310 mono_arch_get_throw_exception_generic (start, sizeof (start), FALSE, TRUE);
316 * arch_get_throw_exception:
318 * Returns a function pointer which can be used to raise
319 * exceptions. The returned function has the following
320 * signature: void (*func) (MonoException *exc);
321 * For example to raise an arithmetic exception you can use:
323 * x86_push_imm (code, mono_get_exception_arithmetic ());
324 * x86_call_code (code, arch_get_throw_exception ());
328 mono_arch_get_throw_exception (MonoTrampInfo **info, gboolean aot)
330 static guint8 start [GENERIC_EXCEPTION_SIZE];
331 static int inited = 0;
339 mono_arch_get_throw_exception_generic (start, sizeof (start), FALSE, FALSE);
345 mono_arch_get_throw_exception_by_name (void)
347 guint8 *start, *code;
350 /* Not used on MIPS */
351 start = code = mono_global_codeman_reserve (size);
352 mips_break (code, 0xfd);
353 mono_arch_flush_icache (start, code - start);
354 mono_profiler_code_buffer_new (start, code - start, MONO_PROFILER_CODE_BUFFER_EXCEPTION_HANDLING, NULL);
359 * mono_arch_get_throw_corlib_exception:
361 * Returns a function pointer which can be used to raise
362 * corlib exceptions. The returned function has the following
363 * signature: void (*func) (guint32 ex_token, guint32 offset);
364 * On MIPS, the offset argument is missing.
367 mono_arch_get_throw_corlib_exception (MonoTrampInfo **info, gboolean aot)
369 static guint8 start [GENERIC_EXCEPTION_SIZE];
370 static int inited = 0;
378 mono_arch_get_throw_exception_generic (start, sizeof (start), TRUE, FALSE);
384 * mono_arch_find_jit_info:
386 * This function is used to gather information from @ctx, and store it in @frame_info.
387 * It unwinds one stack frame, and stores the resulting context into @new_ctx. @lmf
388 * is modified if needed.
389 * Returns TRUE on success, FALSE otherwise.
392 mono_arch_find_jit_info (MonoDomain *domain, MonoJitTlsData *jit_tls,
393 MonoJitInfo *ji, MonoContext *ctx,
394 MonoContext *new_ctx, MonoLMF **lmf,
395 mgreg_t **save_locations,
396 StackFrameInfo *frame)
398 memset (frame, 0, sizeof (StackFrameInfo));
405 gpointer ip = MONO_CONTEXT_GET_IP (ctx);
406 mgreg_t regs [MONO_MAX_IREGS + 1];
408 guint32 unwind_info_len;
411 frame->type = FRAME_TYPE_MANAGED;
413 unwind_info = mono_jinfo_get_unwind_info (ji, &unwind_info_len);
415 for (i = 0; i < MONO_MAX_IREGS; ++i)
416 regs [i] = new_ctx->sc_regs [i];
418 mono_unwind_frame (unwind_info, unwind_info_len, ji->code_start,
419 (guint8*)ji->code_start + ji->code_size,
420 ip, NULL, regs, MONO_MAX_IREGS,
421 save_locations, MONO_MAX_IREGS, &cfa);
423 for (i = 0; i < MONO_MAX_IREGS; ++i)
424 new_ctx->sc_regs [i] = regs [i];
425 new_ctx->sc_pc = regs [mips_ra];
426 new_ctx->sc_regs [mips_sp] = (mgreg_t)cfa;
428 /* we substract 8, so that the IP points into the call instruction */
429 MONO_CONTEXT_SET_IP (new_ctx, new_ctx->sc_pc - 8);
431 /* Sanity check -- we should have made progress here */
432 g_assert (MONO_CONTEXT_GET_SP (new_ctx) != MONO_CONTEXT_GET_SP (ctx));
436 if (((mgreg_t)(*lmf)->previous_lmf) & 2) {
438 * This LMF entry is created by the soft debug code to mark transitions to
439 * managed code done during invokes.
441 MonoLMFExt *ext = (MonoLMFExt*)(*lmf);
443 g_assert (ext->debugger_invoke);
445 memcpy (new_ctx, &ext->ctx, sizeof (MonoContext));
447 *lmf = (gpointer)(((gsize)(*lmf)->previous_lmf) & ~3);
449 frame->type = FRAME_TYPE_DEBUGGER_INVOKE;
454 if (!(*lmf)->method) {
455 #ifdef DEBUG_EXCEPTIONS
456 g_print ("mono_arch_find_jit_info: bad lmf @ %p\n", (void *) *lmf);
460 g_assert (((*lmf)->magic == MIPS_LMF_MAGIC1) || ((*lmf)->magic == MIPS_LMF_MAGIC2));
462 ji = mini_jit_info_table_find (domain, (gpointer)(*lmf)->eip, NULL);
464 // FIXME: This can happen with multiple appdomains (bug #444383)
469 frame->type = FRAME_TYPE_MANAGED_TO_NATIVE;
471 memcpy (&new_ctx->sc_regs, (*lmf)->iregs, sizeof (gulong) * MONO_SAVED_GREGS);
472 memcpy (&new_ctx->sc_fpregs, (*lmf)->fregs, sizeof (float) * MONO_SAVED_FREGS);
473 MONO_CONTEXT_SET_IP (new_ctx, (*lmf)->eip);
474 /* ensure that we've made progress */
475 g_assert (new_ctx->sc_pc != ctx->sc_pc);
477 *lmf = (gpointer)(((gsize)(*lmf)->previous_lmf) & ~3);
486 mono_arch_ip_from_context (void *sigctx)
488 return (gpointer)(gsize)UCONTEXT_REG_PC (sigctx);
494 * Called by resuming from a signal handler.
497 handle_signal_exception (gpointer obj)
499 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
502 memcpy (&ctx, &jit_tls->ex_ctx, sizeof (MonoContext));
504 mono_handle_exception (&ctx, obj);
506 mono_restore_context (&ctx);
510 * This is the function called from the signal handler
513 mono_arch_handle_exception (void *ctx, gpointer obj)
515 #if defined(MONO_CROSS_COMPILE)
516 g_assert_not_reached ();
517 #elif defined(MONO_ARCH_USE_SIGACTION)
521 * Handling the exception in the signal handler is problematic, since the original
522 * signal is disabled, and we could run arbitrary code though the debugger. So
523 * resume into the normal stack and do most work there if possible.
525 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
526 guint64 sp = UCONTEXT_GREGS (sigctx) [mips_sp];
528 /* Pass the ctx parameter in TLS */
529 mono_sigctx_to_monoctx (sigctx, &jit_tls->ex_ctx);
530 /* The others in registers */
531 UCONTEXT_GREGS (sigctx)[mips_a0] = (gsize)obj;
533 /* Allocate a stack frame */
535 UCONTEXT_GREGS (sigctx)[mips_sp] = sp;
537 UCONTEXT_REG_PC (sigctx) = (gsize)handle_signal_exception;
544 mono_sigctx_to_monoctx (ctx, &mctx);
546 result = mono_handle_exception (&mctx, obj);
547 /* restore the context so that returning from the signal handler will invoke
550 mono_monoctx_to_sigctx (&mctx, ctx);
556 * mono_arch_setup_resume_sighandler_ctx:
558 * Setup CTX so execution continues at FUNC.
561 mono_arch_setup_resume_sighandler_ctx (MonoContext *ctx, gpointer func)
563 MONO_CONTEXT_SET_IP (ctx,func);