2 * exceptions-arm.c: exception support for ARM
5 * Dietmar Maurer (dietmar@ximian.com)
6 * Paolo Molaro (lupus@ximian.com)
8 * (C) 2001 Ximian, Inc.
16 #ifndef MONO_CROSS_COMPILE
17 #ifdef HAVE_ASM_SIGCONTEXT_H
18 #include <asm/sigcontext.h>
19 #endif /* def HAVE_ASM_SIGCONTEXT_H */
22 #ifdef HAVE_UCONTEXT_H
24 #endif /* def HAVE_UCONTEXT_H */
26 #include <mono/arch/arm/arm-codegen.h>
27 #include <mono/metadata/appdomain.h>
28 #include <mono/metadata/tabledefs.h>
29 #include <mono/metadata/threads.h>
30 #include <mono/metadata/debug-helpers.h>
31 #include <mono/metadata/exception.h>
32 #include <mono/metadata/mono-debug.h>
36 #include "mono/utils/mono-sigcontext.h"
39 * arch_get_restore_context:
41 * Returns a pointer to a method which restores a previously saved sigcontext.
42 * The first argument in r0 is the pointer to the context.
45 mono_arch_get_restore_context (MonoTrampInfo
**info
, gboolean aot
)
50 MonoJumpInfo
*ji
= NULL
;
51 GSList
*unwind_ops
= NULL
;
53 start
= code
= mono_global_codeman_reserve (128);
56 * Move things to their proper place so we can restore all the registers with
63 ARM_LDR_IMM (code
, ARMREG_IP
, ctx_reg
, G_STRUCT_OFFSET (MonoContext
, eip
));
64 ARM_STR_IMM (code
, ARMREG_IP
, ctx_reg
, G_STRUCT_OFFSET (MonoContext
, regs
) + (ARMREG_PC
* sizeof (mgreg_t
)));
66 ARM_LDR_IMM (code
, ARMREG_IP
, ctx_reg
, G_STRUCT_OFFSET (MonoContext
, esp
));
67 ARM_STR_IMM (code
, ARMREG_IP
, ctx_reg
, G_STRUCT_OFFSET (MonoContext
, regs
) + (ARMREG_SP
* sizeof (mgreg_t
)));
69 /* restore everything */
70 ARM_ADD_REG_IMM8 (code
, ARMREG_IP
, ctx_reg
, G_STRUCT_OFFSET(MonoContext
, regs
));
71 ARM_LDM (code
, ARMREG_IP
, 0xffff);
76 g_assert ((code
- start
) < 128);
78 mono_arch_flush_icache (start
, code
- start
);
81 *info
= mono_tramp_info_create (g_strdup_printf ("restore_context"), start
, code
- start
, ji
, unwind_ops
);
87 * arch_get_call_filter:
89 * Returns a pointer to a method which calls an exception filter. We
90 * also use this function to call finally handlers (we pass NULL as
91 * @exc object in this case).
94 mono_arch_get_call_filter (MonoTrampInfo
**info
, gboolean aot
)
99 MonoJumpInfo
*ji
= NULL
;
100 GSList
*unwind_ops
= NULL
;
102 /* call_filter (MonoContext *ctx, unsigned long eip, gpointer exc) */
103 start
= code
= mono_global_codeman_reserve (320);
105 /* save all the regs on the stack */
106 ARM_MOV_REG_REG (code
, ARMREG_IP
, ARMREG_SP
);
107 ARM_PUSH (code
, MONO_ARM_REGSAVE_MASK
);
109 /* restore all the regs from ctx (in r0), but not sp, the stack pointer */
111 ARM_LDR_IMM (code
, ARMREG_IP
, ctx_reg
, G_STRUCT_OFFSET (MonoContext
, eip
));
112 ARM_ADD_REG_IMM8 (code
, ARMREG_LR
, ctx_reg
, G_STRUCT_OFFSET(MonoContext
, regs
) + (MONO_ARM_FIRST_SAVED_REG
* sizeof (mgreg_t
)));
113 ARM_LDM (code
, ARMREG_LR
, MONO_ARM_REGSAVE_MASK
);
114 /* call handler at eip (r1) and set the first arg with the exception (r2) */
115 ARM_MOV_REG_REG (code
, ARMREG_R0
, ARMREG_R2
);
116 ARM_MOV_REG_REG (code
, ARMREG_LR
, ARMREG_PC
);
117 ARM_MOV_REG_REG (code
, ARMREG_PC
, ARMREG_R1
);
120 ARM_POP_NWB (code
, 0xff0 | ((1 << ARMREG_SP
) | (1 << ARMREG_PC
)));
122 g_assert ((code
- start
) < 320);
124 mono_arch_flush_icache (start
, code
- start
);
127 *info
= mono_tramp_info_create (g_strdup_printf ("call_filter"), start
, code
- start
, ji
, unwind_ops
);
133 mono_arm_throw_exception (MonoObject
*exc
, unsigned long eip
, unsigned long esp
, gulong
*int_regs
, gdouble
*fp_regs
)
135 static void (*restore_context
) (MonoContext
*);
137 gboolean rethrow
= eip
& 1;
139 if (!restore_context
)
140 restore_context
= mono_get_restore_context ();
142 eip
&= ~1; /* clear the optional rethrow bit */
143 /* adjust eip so that it point into the call instruction */
146 /*printf ("stack in throw: %p\n", esp);*/
147 MONO_CONTEXT_SET_BP (&ctx
, int_regs
[ARMREG_FP
- 4]);
148 MONO_CONTEXT_SET_SP (&ctx
, esp
);
149 MONO_CONTEXT_SET_IP (&ctx
, eip
);
150 memcpy (((guint8
*)&ctx
.regs
) + (ARMREG_R4
* sizeof (mgreg_t
)), int_regs
, 8 * sizeof (mgreg_t
));
151 /* memcpy (&ctx.fregs, fp_regs, sizeof (double) * MONO_SAVED_FREGS); */
153 if (mono_object_isinst (exc
, mono_defaults
.exception_class
)) {
154 MonoException
*mono_ex
= (MonoException
*)exc
;
156 mono_ex
->stack_trace
= NULL
;
158 mono_handle_exception (&ctx
, exc
, (gpointer
)(eip
+ 4), FALSE
);
159 restore_context (&ctx
);
160 g_assert_not_reached ();
164 mono_arm_throw_exception_by_token (guint32 type_token
, unsigned long eip
, unsigned long esp
, gulong
*int_regs
, gdouble
*fp_regs
)
166 /* Clear thumb bit */
169 mono_arm_throw_exception ((MonoObject
*)mono_exception_from_token (mono_defaults
.corlib
, type_token
), eip
, esp
, int_regs
, fp_regs
);
173 mono_arm_resume_unwind (guint32 dummy1
, unsigned long eip
, unsigned long esp
, gulong
*int_regs
, gdouble
*fp_regs
)
177 eip
&= ~1; /* clear the optional rethrow bit */
178 /* adjust eip so that it point into the call instruction */
181 MONO_CONTEXT_SET_BP (&ctx
, int_regs
[ARMREG_FP
- 4]);
182 MONO_CONTEXT_SET_SP (&ctx
, esp
);
183 MONO_CONTEXT_SET_IP (&ctx
, eip
);
184 memcpy (((guint8
*)&ctx
.regs
) + (ARMREG_R4
* sizeof (mgreg_t
)), int_regs
, 8 * sizeof (mgreg_t
));
186 mono_resume_unwind (&ctx
);
190 * get_throw_trampoline:
192 * Returns a function pointer which can be used to raise
193 * exceptions. The returned function has the following
194 * signature: void (*func) (MonoException *exc); or
195 * void (*func) (guint32 ex_token, guint8* ip);
199 get_throw_trampoline (int size
, gboolean corlib
, gboolean rethrow
, gboolean llvm
, gboolean resume_unwind
, const char *tramp_name
, MonoTrampInfo
**info
, gboolean aot
)
203 MonoJumpInfo
*ji
= NULL
;
204 GSList
*unwind_ops
= NULL
;
206 code
= start
= mono_global_codeman_reserve (size
);
208 mono_add_unwind_op_def_cfa (unwind_ops
, code
, start
, ARMREG_SP
, 0);
210 /* save all the regs on the stack */
211 ARM_MOV_REG_REG (code
, ARMREG_IP
, ARMREG_SP
);
212 ARM_PUSH (code
, MONO_ARM_REGSAVE_MASK
);
214 mono_add_unwind_op_def_cfa (unwind_ops
, code
, start
, ARMREG_SP
, MONO_ARM_NUM_SAVED_REGS
* sizeof (mgreg_t
));
215 mono_add_unwind_op_offset (unwind_ops
, code
, start
, ARMREG_LR
, - sizeof (mgreg_t
));
217 /* call throw_exception (exc, ip, sp, int_regs, fp_regs) */
219 ARM_ADD_REG_IMM8 (code
, ARMREG_R2
, ARMREG_SP
, MONO_ARM_NUM_SAVED_REGS
* sizeof (mgreg_t
));
220 /* exc is already in place in r0 */
222 /* The caller ip is already in R1 */
224 /* Negate the ip adjustment done in mono_arm_throw_exception */
225 ARM_ADD_REG_IMM8 (code
, ARMREG_R1
, ARMREG_R1
, 4);
227 ARM_MOV_REG_REG (code
, ARMREG_R1
, ARMREG_LR
); /* caller ip */
229 /* FIXME: pointer to the saved fp regs */
230 /*pos = alloc_size - sizeof (double) * MONO_SAVED_FREGS;
231 ppc_addi (code, ppc_r7, ppc_sp, pos);*/
232 /* pointer to the saved int regs */
233 ARM_MOV_REG_REG (code
, ARMREG_R3
, ARMREG_SP
); /* the pushed regs */
234 /* we encode rethrow in the ip, so we avoid args on the stack */
235 ARM_ORR_REG_IMM8 (code
, ARMREG_R1
, ARMREG_R1
, rethrow
);
238 const char *icall_name
;
241 icall_name
= "mono_arm_resume_unwind";
243 icall_name
= "mono_arm_throw_exception_by_token";
245 icall_name
= "mono_arm_throw_exception";
247 ji
= mono_patch_info_list_prepend (ji
, code
- start
, MONO_PATCH_INFO_JIT_ICALL_ADDR
, icall_name
);
248 ARM_LDR_IMM (code
, ARMREG_IP
, ARMREG_PC
, 0);
250 *(gpointer
*)(gpointer
)code
= NULL
;
252 ARM_LDR_REG_REG (code
, ARMREG_IP
, ARMREG_PC
, ARMREG_IP
);
254 code
= mono_arm_emit_load_imm (code
, ARMREG_IP
, GPOINTER_TO_UINT (resume_unwind
? (gpointer
)mono_arm_resume_unwind
: (corlib
? (gpointer
)mono_arm_throw_exception_by_token
: (gpointer
)mono_arm_throw_exception
)));
256 ARM_MOV_REG_REG (code
, ARMREG_LR
, ARMREG_PC
);
257 ARM_MOV_REG_REG (code
, ARMREG_PC
, ARMREG_IP
);
258 /* we should never reach this breakpoint */
260 g_assert ((code
- start
) < size
);
261 mono_arch_flush_icache (start
, code
- start
);
264 *info
= mono_tramp_info_create (g_strdup_printf (tramp_name
), start
, code
- start
, ji
, unwind_ops
);
270 * arch_get_throw_exception:
272 * Returns a function pointer which can be used to raise
273 * exceptions. The returned function has the following
274 * signature: void (*func) (MonoException *exc);
275 * For example to raise an arithmetic exception you can use:
277 * x86_push_imm (code, mono_get_exception_arithmetic ());
278 * x86_call_code (code, arch_get_throw_exception ());
282 mono_arch_get_throw_exception (MonoTrampInfo
**info
, gboolean aot
)
284 return get_throw_trampoline (132, FALSE
, FALSE
, FALSE
, FALSE
, "throw_exception", info
, aot
);
288 * mono_arch_get_rethrow_exception:
290 * Returns a function pointer which can be used to rethrow
291 * exceptions. The returned function has the following
292 * signature: void (*func) (MonoException *exc);
296 mono_arch_get_rethrow_exception (MonoTrampInfo
**info
, gboolean aot
)
298 return get_throw_trampoline (132, FALSE
, TRUE
, FALSE
, FALSE
, "rethrow_exception", info
, aot
);
302 * mono_arch_get_throw_corlib_exception:
304 * Returns a function pointer which can be used to raise
305 * corlib exceptions. The returned function has the following
306 * signature: void (*func) (guint32 ex_token, guint32 offset);
307 * Here, offset is the offset which needs to be substracted from the caller IP
308 * to get the IP of the throw. Passing the offset has the advantage that it
309 * needs no relocations in the caller.
310 * On ARM, the ip is passed instead of an offset.
313 mono_arch_get_throw_corlib_exception (MonoTrampInfo
**info
, gboolean aot
)
315 return get_throw_trampoline (168, TRUE
, FALSE
, FALSE
, FALSE
, "throw_corlib_exception", info
, aot
);
319 mono_arm_get_exception_trampolines (gboolean aot
)
322 GSList
*tramps
= NULL
;
324 /* LLVM uses the normal trampolines, but with a different name */
325 get_throw_trampoline (168, TRUE
, FALSE
, FALSE
, FALSE
, "llvm_throw_corlib_exception_trampoline", &info
, aot
);
326 tramps
= g_slist_prepend (tramps
, info
);
328 get_throw_trampoline (168, TRUE
, FALSE
, TRUE
, FALSE
, "llvm_throw_corlib_exception_abs_trampoline", &info
, aot
);
329 tramps
= g_slist_prepend (tramps
, info
);
331 get_throw_trampoline (168, FALSE
, FALSE
, FALSE
, TRUE
, "llvm_resume_unwind_trampoline", &info
, aot
);
332 tramps
= g_slist_prepend (tramps
, info
);
338 mono_arch_exceptions_init (void)
344 tramp
= mono_aot_get_trampoline ("llvm_throw_corlib_exception_trampoline");
345 mono_register_jit_icall (tramp
, "llvm_throw_corlib_exception_trampoline", NULL
, TRUE
);
346 tramp
= mono_aot_get_trampoline ("llvm_throw_corlib_exception_abs_trampoline");
347 mono_register_jit_icall (tramp
, "llvm_throw_corlib_exception_abs_trampoline", NULL
, TRUE
);
348 tramp
= mono_aot_get_trampoline ("llvm_resume_unwind_trampoline");
349 mono_register_jit_icall (tramp
, "llvm_resume_unwind_trampoline", NULL
, TRUE
);
351 tramps
= mono_arm_get_exception_trampolines (FALSE
);
352 for (l
= tramps
; l
; l
= l
->next
) {
353 MonoTrampInfo
*info
= l
->data
;
355 mono_register_jit_icall (info
->code
, g_strdup (info
->name
), NULL
, TRUE
);
356 mono_save_trampoline_xdebug_info (info
);
357 mono_tramp_info_free (info
);
359 g_slist_free (tramps
);
364 * mono_arch_find_jit_info:
366 * See exceptions-amd64.c for docs;
369 mono_arch_find_jit_info (MonoDomain
*domain
, MonoJitTlsData
*jit_tls
,
370 MonoJitInfo
*ji
, MonoContext
*ctx
,
371 MonoContext
*new_ctx
, MonoLMF
**lmf
,
372 mgreg_t
**save_locations
,
373 StackFrameInfo
*frame
)
375 gpointer ip
= MONO_CONTEXT_GET_IP (ctx
);
377 memset (frame
, 0, sizeof (StackFrameInfo
));
384 gssize regs
[MONO_MAX_IREGS
+ 1];
386 guint32 unwind_info_len
;
389 frame
->type
= FRAME_TYPE_MANAGED
;
392 unwind_info
= mono_aot_get_unwind_info (ji
, &unwind_info_len
);
394 unwind_info
= mono_get_cached_unwind_info (ji
->used_regs
, &unwind_info_len
);
396 for (i
= 0; i
< 16; ++i
)
397 regs
[i
] = new_ctx
->regs
[i
];
398 regs
[ARMREG_SP
] = new_ctx
->esp
;
400 mono_unwind_frame (unwind_info
, unwind_info_len
, ji
->code_start
,
401 (guint8
*)ji
->code_start
+ ji
->code_size
,
402 ip
, regs
, MONO_MAX_IREGS
,
403 save_locations
, MONO_MAX_IREGS
, &cfa
);
405 for (i
= 0; i
< 16; ++i
)
406 new_ctx
->regs
[i
] = regs
[i
];
407 new_ctx
->eip
= regs
[ARMREG_LR
];
408 new_ctx
->esp
= (gsize
)cfa
;
410 if (*lmf
&& (MONO_CONTEXT_GET_SP (ctx
) >= (gpointer
)(*lmf
)->esp
)) {
411 /* remove any unused lmf */
412 *lmf
= (gpointer
)(((gsize
)(*lmf
)->previous_lmf
) & ~3);
415 /* Clear thumb bit */
418 /* we substract 1, so that the IP points into the call instruction */
424 if (((gsize
)(*lmf
)->previous_lmf
) & 2) {
426 * This LMF entry is created by the soft debug code to mark transitions to
427 * managed code done during invokes.
429 MonoLMFExt
*ext
= (MonoLMFExt
*)(*lmf
);
431 g_assert (ext
->debugger_invoke
);
433 memcpy (new_ctx
, &ext
->ctx
, sizeof (MonoContext
));
435 *lmf
= (gpointer
)(((gsize
)(*lmf
)->previous_lmf
) & ~3);
437 frame
->type
= FRAME_TYPE_DEBUGGER_INVOKE
;
442 frame
->type
= FRAME_TYPE_MANAGED_TO_NATIVE
;
444 if ((ji
= mini_jit_info_table_find (domain
, (gpointer
)(*lmf
)->eip
, NULL
))) {
449 frame
->method
= (*lmf
)->method
;
453 * The LMF is saved at the start of the method using:
454 * ARM_MOV_REG_REG (code, ARMREG_IP, ARMREG_SP)
455 * ARM_PUSH (code, 0x5ff0);
456 * So it stores the register state as it existed at the caller.
458 memcpy (&new_ctx
->regs
[0], &(*lmf
)->iregs
[0], sizeof (mgreg_t
) * 13);
460 new_ctx
->regs
[ARMREG_LR
] = (*lmf
)->iregs
[ARMREG_LR
- 1];
461 new_ctx
->esp
= (*lmf
)->iregs
[ARMREG_IP
];
462 new_ctx
->eip
= new_ctx
->regs
[ARMREG_LR
];
464 /* Clear thumb bit */
467 /* we substract 1, so that the IP points into the call instruction */
470 *lmf
= (gpointer
)(((gsize
)(*lmf
)->previous_lmf
) & ~3);
479 mono_arch_sigctx_to_monoctx (void *sigctx
, MonoContext
*mctx
)
481 #ifdef MONO_CROSS_COMPILE
482 g_assert_not_reached ();
484 g_assert_not_reached ();
486 arm_ucontext
*my_uc
= sigctx
;
488 mctx
->eip
= UCONTEXT_REG_PC (my_uc
);
489 mctx
->esp
= UCONTEXT_REG_SP (my_uc
);
490 memcpy (&mctx
->regs
, &UCONTEXT_REG_R0 (my_uc
), sizeof (mgreg_t
) * 16);
495 mono_arch_monoctx_to_sigctx (MonoContext
*mctx
, void *ctx
)
497 #ifdef MONO_CROSS_COMPILE
498 g_assert_not_reached ();
500 g_assert_not_reached ();
502 arm_ucontext
*my_uc
= ctx
;
504 UCONTEXT_REG_PC (my_uc
) = mctx
->eip
;
505 UCONTEXT_REG_SP (my_uc
) = mctx
->regs
[ARMREG_FP
];
506 /* The upper registers are not guaranteed to be valid */
507 memcpy (&UCONTEXT_REG_R0 (my_uc
), &mctx
->regs
, sizeof (mgreg_t
) * 12);
514 * Called by resuming from a signal handler.
517 handle_signal_exception (gpointer obj
, gboolean test_only
)
519 MonoJitTlsData
*jit_tls
= TlsGetValue (mono_jit_tls_id
);
521 static void (*restore_context
) (MonoContext
*);
523 if (!restore_context
)
524 restore_context
= mono_get_restore_context ();
526 memcpy (&ctx
, &jit_tls
->ex_ctx
, sizeof (MonoContext
));
528 mono_handle_exception (&ctx
, obj
, MONO_CONTEXT_GET_IP (&ctx
), test_only
);
530 restore_context (&ctx
);
534 * This works around a gcc 4.5 bug:
535 * https://bugs.launchpad.net/ubuntu/+source/gcc-4.5/+bug/721531
537 #if defined(__GNUC__)
538 __attribute__((noinline
))
541 get_handle_signal_exception_addr (void)
543 return handle_signal_exception
;
547 * This is the function called from the signal handler
550 mono_arch_handle_exception (void *ctx
, gpointer obj
, gboolean test_only
)
552 #if defined(MONO_CROSS_COMPILE)
553 g_assert_not_reached ();
554 #elif defined(MONO_ARCH_USE_SIGACTION)
555 arm_ucontext
*sigctx
= ctx
;
557 * Handling the exception in the signal handler is problematic, since the original
558 * signal is disabled, and we could run arbitrary code though the debugger. So
559 * resume into the normal stack and do most work there if possible.
561 MonoJitTlsData
*jit_tls
= TlsGetValue (mono_jit_tls_id
);
562 guint64 sp
= UCONTEXT_REG_SP (sigctx
);
564 /* Pass the ctx parameter in TLS */
565 mono_arch_sigctx_to_monoctx (sigctx
, &jit_tls
->ex_ctx
);
566 /* The others in registers */
567 UCONTEXT_REG_R0 (sigctx
) = (gsize
)obj
;
568 UCONTEXT_REG_R1 (sigctx
) = test_only
;
570 /* Allocate a stack frame */
572 UCONTEXT_REG_SP (sigctx
) = sp
;
574 UCONTEXT_REG_PC (sigctx
) = (gsize
)get_handle_signal_exception_addr ();
575 #ifdef UCONTEXT_REG_CPSR
576 if ((gsize
)UCONTEXT_REG_PC (sigctx
) & 1)
577 /* Transition to thumb */
578 UCONTEXT_REG_CPSR (sigctx
) |= (1 << 5);
580 /* Transition to ARM */
581 UCONTEXT_REG_CPSR (sigctx
) &= ~(1 << 5);
589 mono_arch_sigctx_to_monoctx (ctx
, &mctx
);
591 result
= mono_handle_exception (&mctx
, obj
, (gpointer
)mctx
.eip
, test_only
);
592 /* restore the context so that returning from the signal handler will invoke
595 mono_arch_monoctx_to_sigctx (&mctx
, ctx
);
601 mono_arch_ip_from_context (void *sigctx
)
603 #ifdef MONO_CROSS_COMPILE
604 g_assert_not_reached ();
606 g_assert_not_reached ();
608 arm_ucontext
*my_uc
= sigctx
;
609 return (void*) UCONTEXT_REG_PC (my_uc
);