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/arch/arm/arm-vfp-codegen.h>
28 #include <mono/metadata/appdomain.h>
29 #include <mono/metadata/tabledefs.h>
30 #include <mono/metadata/threads.h>
31 #include <mono/metadata/debug-helpers.h>
32 #include <mono/metadata/exception.h>
33 #include <mono/metadata/mono-debug.h>
37 #include "mono/utils/mono-sigcontext.h"
40 * arch_get_restore_context:
42 * Returns a pointer to a method which restores a previously saved sigcontext.
43 * The first argument in r0 is the pointer to the context.
46 mono_arch_get_restore_context (MonoTrampInfo
**info
, gboolean aot
)
51 MonoJumpInfo
*ji
= NULL
;
52 GSList
*unwind_ops
= NULL
;
54 start
= code
= mono_global_codeman_reserve (128);
57 * Move things to their proper place so we can restore all the registers with
63 #if defined(ARM_FPU_VFP)
64 ARM_ADD_REG_IMM8 (code
, ARMREG_IP
, ctx_reg
, G_STRUCT_OFFSET (MonoContext
, fregs
));
65 ARM_FLDMD (code
, ARM_VFP_D0
, 16, ARMREG_IP
);
69 ARM_LDR_IMM (code
, ARMREG_IP
, ctx_reg
, G_STRUCT_OFFSET (MonoContext
, pc
));
70 ARM_STR_IMM (code
, ARMREG_IP
, ctx_reg
, G_STRUCT_OFFSET (MonoContext
, regs
) + (ARMREG_PC
* sizeof (mgreg_t
)));
72 /* restore everything */
73 ARM_ADD_REG_IMM8 (code
, ARMREG_IP
, ctx_reg
, G_STRUCT_OFFSET(MonoContext
, regs
));
74 ARM_LDM (code
, ARMREG_IP
, 0xffff);
79 g_assert ((code
- start
) < 128);
81 mono_arch_flush_icache (start
, code
- start
);
84 *info
= mono_tramp_info_create (g_strdup_printf ("restore_context"), start
, code
- start
, ji
, unwind_ops
);
90 * arch_get_call_filter:
92 * Returns a pointer to a method which calls an exception filter. We
93 * also use this function to call finally handlers (we pass NULL as
94 * @exc object in this case).
97 mono_arch_get_call_filter (MonoTrampInfo
**info
, gboolean aot
)
102 MonoJumpInfo
*ji
= NULL
;
103 GSList
*unwind_ops
= NULL
;
105 /* call_filter (MonoContext *ctx, unsigned long eip, gpointer exc) */
106 start
= code
= mono_global_codeman_reserve (320);
108 /* save all the regs on the stack */
109 ARM_MOV_REG_REG (code
, ARMREG_IP
, ARMREG_SP
);
110 ARM_PUSH (code
, MONO_ARM_REGSAVE_MASK
);
112 /* restore all the regs from ctx (in r0), but not sp, the stack pointer */
114 ARM_LDR_IMM (code
, ARMREG_IP
, ctx_reg
, G_STRUCT_OFFSET (MonoContext
, pc
));
115 ARM_ADD_REG_IMM8 (code
, ARMREG_LR
, ctx_reg
, G_STRUCT_OFFSET(MonoContext
, regs
) + (MONO_ARM_FIRST_SAVED_REG
* sizeof (mgreg_t
)));
116 ARM_LDM (code
, ARMREG_LR
, MONO_ARM_REGSAVE_MASK
);
117 /* call handler at eip (r1) and set the first arg with the exception (r2) */
118 ARM_MOV_REG_REG (code
, ARMREG_R0
, ARMREG_R2
);
119 ARM_MOV_REG_REG (code
, ARMREG_LR
, ARMREG_PC
);
120 ARM_MOV_REG_REG (code
, ARMREG_PC
, ARMREG_R1
);
123 ARM_POP_NWB (code
, 0xff0 | ((1 << ARMREG_SP
) | (1 << ARMREG_PC
)));
125 g_assert ((code
- start
) < 320);
127 mono_arch_flush_icache (start
, code
- start
);
130 *info
= mono_tramp_info_create (g_strdup_printf ("call_filter"), start
, code
- start
, ji
, unwind_ops
);
136 mono_arm_throw_exception (MonoObject
*exc
, mgreg_t pc
, mgreg_t sp
, mgreg_t
*int_regs
, gdouble
*fp_regs
)
138 static void (*restore_context
) (MonoContext
*);
140 gboolean rethrow
= pc
& 1;
142 if (!restore_context
)
143 restore_context
= mono_get_restore_context ();
145 pc
&= ~1; /* clear the optional rethrow bit */
146 /* adjust eip so that it point into the call instruction */
149 /*printf ("stack in throw: %p\n", esp);*/
150 MONO_CONTEXT_SET_BP (&ctx
, int_regs
[ARMREG_FP
- 4]);
151 MONO_CONTEXT_SET_SP (&ctx
, sp
);
152 MONO_CONTEXT_SET_IP (&ctx
, pc
);
153 memcpy (((guint8
*)&ctx
.regs
) + (ARMREG_R4
* sizeof (mgreg_t
)), int_regs
, 8 * sizeof (mgreg_t
));
154 memcpy (&ctx
.fregs
, fp_regs
, sizeof (double) * 16);
156 if (mono_object_isinst (exc
, mono_defaults
.exception_class
)) {
157 MonoException
*mono_ex
= (MonoException
*)exc
;
159 mono_ex
->stack_trace
= NULL
;
161 mono_handle_exception (&ctx
, exc
);
162 restore_context (&ctx
);
163 g_assert_not_reached ();
167 mono_arm_throw_exception_by_token (guint32 type_token
, mgreg_t pc
, mgreg_t sp
, mgreg_t
*int_regs
, gdouble
*fp_regs
)
169 /* Clear thumb bit */
172 mono_arm_throw_exception ((MonoObject
*)mono_exception_from_token (mono_defaults
.corlib
, type_token
), pc
, sp
, int_regs
, fp_regs
);
176 mono_arm_resume_unwind (guint32 dummy1
, mgreg_t pc
, mgreg_t sp
, mgreg_t
*int_regs
, gdouble
*fp_regs
)
180 pc
&= ~1; /* clear the optional rethrow bit */
181 /* adjust eip so that it point into the call instruction */
184 MONO_CONTEXT_SET_BP (&ctx
, int_regs
[ARMREG_FP
- 4]);
185 MONO_CONTEXT_SET_SP (&ctx
, sp
);
186 MONO_CONTEXT_SET_IP (&ctx
, pc
);
187 memcpy (((guint8
*)&ctx
.regs
) + (ARMREG_R4
* sizeof (mgreg_t
)), int_regs
, 8 * sizeof (mgreg_t
));
189 mono_resume_unwind (&ctx
);
193 * get_throw_trampoline:
195 * Returns a function pointer which can be used to raise
196 * exceptions. The returned function has the following
197 * signature: void (*func) (MonoException *exc); or
198 * void (*func) (guint32 ex_token, guint8* ip);
202 get_throw_trampoline (int size
, gboolean corlib
, gboolean rethrow
, gboolean llvm
, gboolean resume_unwind
, const char *tramp_name
, MonoTrampInfo
**info
, gboolean aot
)
206 MonoJumpInfo
*ji
= NULL
;
207 GSList
*unwind_ops
= NULL
;
210 code
= start
= mono_global_codeman_reserve (size
);
212 mono_add_unwind_op_def_cfa (unwind_ops
, code
, start
, ARMREG_SP
, 0);
214 /* save all the regs on the stack */
215 ARM_MOV_REG_REG (code
, ARMREG_IP
, ARMREG_SP
);
216 ARM_PUSH (code
, MONO_ARM_REGSAVE_MASK
);
218 cfa_offset
= MONO_ARM_NUM_SAVED_REGS
* sizeof (mgreg_t
);
219 mono_add_unwind_op_def_cfa (unwind_ops
, code
, start
, ARMREG_SP
, cfa_offset
);
220 mono_add_unwind_op_offset (unwind_ops
, code
, start
, ARMREG_LR
, - sizeof (mgreg_t
));
223 ARM_SUB_REG_IMM8 (code
, ARMREG_SP
, ARMREG_SP
, sizeof (double) * 16);
224 cfa_offset
+= sizeof (double) * 16;
225 mono_add_unwind_op_def_cfa_offset (unwind_ops
, code
, start
, cfa_offset
);
226 #if defined(ARM_FPU_VFP)
227 ARM_FSTMD (code
, ARM_VFP_D0
, 16, ARMREG_SP
);
231 ARM_SUB_REG_IMM8 (code
, ARMREG_SP
, ARMREG_SP
, 8);
233 mono_add_unwind_op_def_cfa_offset (unwind_ops
, code
, start
, cfa_offset
);
235 /* call throw_exception (exc, ip, sp, int_regs, fp_regs) */
237 ARM_ADD_REG_IMM8 (code
, ARMREG_R2
, ARMREG_SP
, cfa_offset
);
238 /* exc is already in place in r0 */
240 /* The caller ip is already in R1 */
242 /* Negate the ip adjustment done in mono_arm_throw_exception */
243 ARM_ADD_REG_IMM8 (code
, ARMREG_R1
, ARMREG_R1
, 4);
245 ARM_MOV_REG_REG (code
, ARMREG_R1
, ARMREG_LR
); /* caller ip */
248 ARM_ADD_REG_IMM8 (code
, ARMREG_R3
, ARMREG_SP
, (cfa_offset
- (MONO_ARM_NUM_SAVED_REGS
* sizeof (mgreg_t
))));
249 /* we encode rethrow in the ip */
250 ARM_ORR_REG_IMM8 (code
, ARMREG_R1
, ARMREG_R1
, rethrow
);
252 ARM_ADD_REG_IMM8 (code
, ARMREG_LR
, ARMREG_SP
, 8);
253 ARM_STR_IMM (code
, ARMREG_LR
, ARMREG_SP
, 0);
256 const char *icall_name
;
259 icall_name
= "mono_arm_resume_unwind";
261 icall_name
= "mono_arm_throw_exception_by_token";
263 icall_name
= "mono_arm_throw_exception";
265 ji
= mono_patch_info_list_prepend (ji
, code
- start
, MONO_PATCH_INFO_JIT_ICALL_ADDR
, icall_name
);
266 ARM_LDR_IMM (code
, ARMREG_IP
, ARMREG_PC
, 0);
268 *(gpointer
*)(gpointer
)code
= NULL
;
270 ARM_LDR_REG_REG (code
, ARMREG_IP
, ARMREG_PC
, ARMREG_IP
);
272 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
)));
274 ARM_MOV_REG_REG (code
, ARMREG_LR
, ARMREG_PC
);
275 ARM_MOV_REG_REG (code
, ARMREG_PC
, ARMREG_IP
);
276 /* we should never reach this breakpoint */
278 g_assert ((code
- start
) < size
);
279 mono_arch_flush_icache (start
, code
- start
);
282 *info
= mono_tramp_info_create (g_strdup_printf (tramp_name
), start
, code
- start
, ji
, unwind_ops
);
288 * arch_get_throw_exception:
290 * Returns a function pointer which can be used to raise
291 * exceptions. The returned function has the following
292 * signature: void (*func) (MonoException *exc);
293 * For example to raise an arithmetic exception you can use:
295 * x86_push_imm (code, mono_get_exception_arithmetic ());
296 * x86_call_code (code, arch_get_throw_exception ());
300 mono_arch_get_throw_exception (MonoTrampInfo
**info
, gboolean aot
)
302 return get_throw_trampoline (132, FALSE
, FALSE
, FALSE
, FALSE
, "throw_exception", info
, aot
);
306 * mono_arch_get_rethrow_exception:
308 * Returns a function pointer which can be used to rethrow
309 * exceptions. The returned function has the following
310 * signature: void (*func) (MonoException *exc);
314 mono_arch_get_rethrow_exception (MonoTrampInfo
**info
, gboolean aot
)
316 return get_throw_trampoline (132, FALSE
, TRUE
, FALSE
, FALSE
, "rethrow_exception", info
, aot
);
320 * mono_arch_get_throw_corlib_exception:
322 * Returns a function pointer which can be used to raise
323 * corlib exceptions. The returned function has the following
324 * signature: void (*func) (guint32 ex_token, guint32 offset);
325 * Here, offset is the offset which needs to be substracted from the caller IP
326 * to get the IP of the throw. Passing the offset has the advantage that it
327 * needs no relocations in the caller.
328 * On ARM, the ip is passed instead of an offset.
331 mono_arch_get_throw_corlib_exception (MonoTrampInfo
**info
, gboolean aot
)
333 return get_throw_trampoline (168, TRUE
, FALSE
, FALSE
, FALSE
, "throw_corlib_exception", info
, aot
);
337 mono_arm_get_exception_trampolines (gboolean aot
)
340 GSList
*tramps
= NULL
;
342 /* LLVM uses the normal trampolines, but with a different name */
343 get_throw_trampoline (168, TRUE
, FALSE
, FALSE
, FALSE
, "llvm_throw_corlib_exception_trampoline", &info
, aot
);
344 tramps
= g_slist_prepend (tramps
, info
);
346 get_throw_trampoline (168, TRUE
, FALSE
, TRUE
, FALSE
, "llvm_throw_corlib_exception_abs_trampoline", &info
, aot
);
347 tramps
= g_slist_prepend (tramps
, info
);
349 get_throw_trampoline (168, FALSE
, FALSE
, FALSE
, TRUE
, "llvm_resume_unwind_trampoline", &info
, aot
);
350 tramps
= g_slist_prepend (tramps
, info
);
356 mono_arch_exceptions_init (void)
362 tramp
= mono_aot_get_trampoline ("llvm_throw_corlib_exception_trampoline");
363 mono_register_jit_icall (tramp
, "llvm_throw_corlib_exception_trampoline", NULL
, TRUE
);
364 tramp
= mono_aot_get_trampoline ("llvm_throw_corlib_exception_abs_trampoline");
365 mono_register_jit_icall (tramp
, "llvm_throw_corlib_exception_abs_trampoline", NULL
, TRUE
);
366 tramp
= mono_aot_get_trampoline ("llvm_resume_unwind_trampoline");
367 mono_register_jit_icall (tramp
, "llvm_resume_unwind_trampoline", NULL
, TRUE
);
369 tramps
= mono_arm_get_exception_trampolines (FALSE
);
370 for (l
= tramps
; l
; l
= l
->next
) {
371 MonoTrampInfo
*info
= l
->data
;
373 mono_register_jit_icall (info
->code
, g_strdup (info
->name
), NULL
, TRUE
);
374 mono_save_trampoline_xdebug_info (info
);
375 mono_tramp_info_free (info
);
377 g_slist_free (tramps
);
382 * mono_arch_find_jit_info:
384 * See exceptions-amd64.c for docs;
387 mono_arch_find_jit_info (MonoDomain
*domain
, MonoJitTlsData
*jit_tls
,
388 MonoJitInfo
*ji
, MonoContext
*ctx
,
389 MonoContext
*new_ctx
, MonoLMF
**lmf
,
390 mgreg_t
**save_locations
,
391 StackFrameInfo
*frame
)
393 gpointer ip
= MONO_CONTEXT_GET_IP (ctx
);
395 memset (frame
, 0, sizeof (StackFrameInfo
));
402 gssize regs
[MONO_MAX_IREGS
+ 1];
404 guint32 unwind_info_len
;
407 frame
->type
= FRAME_TYPE_MANAGED
;
410 unwind_info
= mono_aot_get_unwind_info (ji
, &unwind_info_len
);
412 unwind_info
= mono_get_cached_unwind_info (ji
->used_regs
, &unwind_info_len
);
414 for (i
= 0; i
< 16; ++i
)
415 regs
[i
] = new_ctx
->regs
[i
];
417 mono_unwind_frame (unwind_info
, unwind_info_len
, ji
->code_start
,
418 (guint8
*)ji
->code_start
+ ji
->code_size
,
419 ip
, regs
, MONO_MAX_IREGS
,
420 save_locations
, MONO_MAX_IREGS
, &cfa
);
422 for (i
= 0; i
< 16; ++i
)
423 new_ctx
->regs
[i
] = regs
[i
];
424 new_ctx
->pc
= regs
[ARMREG_LR
];
425 new_ctx
->regs
[ARMREG_SP
] = (gsize
)cfa
;
427 if (*lmf
&& (MONO_CONTEXT_GET_SP (ctx
) >= (gpointer
)(*lmf
)->sp
)) {
428 /* remove any unused lmf */
429 *lmf
= (gpointer
)(((gsize
)(*lmf
)->previous_lmf
) & ~3);
432 /* Clear thumb bit */
435 /* we substract 1, so that the IP points into the call instruction */
441 if (((gsize
)(*lmf
)->previous_lmf
) & 2) {
443 * This LMF entry is created by the soft debug code to mark transitions to
444 * managed code done during invokes.
446 MonoLMFExt
*ext
= (MonoLMFExt
*)(*lmf
);
448 g_assert (ext
->debugger_invoke
);
450 memcpy (new_ctx
, &ext
->ctx
, sizeof (MonoContext
));
452 *lmf
= (gpointer
)(((gsize
)(*lmf
)->previous_lmf
) & ~3);
454 frame
->type
= FRAME_TYPE_DEBUGGER_INVOKE
;
459 frame
->type
= FRAME_TYPE_MANAGED_TO_NATIVE
;
461 if ((ji
= mini_jit_info_table_find (domain
, (gpointer
)(*lmf
)->ip
, NULL
))) {
466 frame
->method
= (*lmf
)->method
;
470 * The LMF is saved at the start of the method using:
471 * ARM_MOV_REG_REG (code, ARMREG_IP, ARMREG_SP)
472 * ARM_PUSH (code, 0x5ff0);
473 * So it stores the register state as it existed at the caller. We need to
474 * produce the register state which existed at the time of the call which
475 * transitioned to native call, so we save the sp/fp/ip in the LMF.
477 memcpy (&new_ctx
->regs
[0], &(*lmf
)->iregs
[0], sizeof (mgreg_t
) * 13);
478 new_ctx
->pc
= (*lmf
)->ip
;
479 new_ctx
->regs
[ARMREG_SP
] = (*lmf
)->sp
;
480 new_ctx
->regs
[ARMREG_FP
] = (*lmf
)->fp
;
482 /* Clear thumb bit */
485 /* we substract 1, so that the IP points into the call instruction */
488 *lmf
= (gpointer
)(((gsize
)(*lmf
)->previous_lmf
) & ~3);
497 mono_arch_sigctx_to_monoctx (void *sigctx
, MonoContext
*mctx
)
499 mono_sigctx_to_monoctx (sigctx
, mctx
);
503 mono_arch_monoctx_to_sigctx (MonoContext
*mctx
, void *ctx
)
505 mono_monoctx_to_sigctx (mctx
, ctx
);
511 * Called by resuming from a signal handler.
514 handle_signal_exception (gpointer obj
)
516 MonoJitTlsData
*jit_tls
= mono_native_tls_get_value (mono_jit_tls_id
);
518 static void (*restore_context
) (MonoContext
*);
520 if (!restore_context
)
521 restore_context
= mono_get_restore_context ();
523 memcpy (&ctx
, &jit_tls
->ex_ctx
, sizeof (MonoContext
));
525 mono_handle_exception (&ctx
, obj
);
527 restore_context (&ctx
);
531 * This works around a gcc 4.5 bug:
532 * https://bugs.launchpad.net/ubuntu/+source/gcc-4.5/+bug/721531
534 #if defined(__GNUC__)
535 __attribute__((noinline
))
538 get_handle_signal_exception_addr (void)
540 return handle_signal_exception
;
544 * This is the function called from the signal handler
547 mono_arch_handle_exception (void *ctx
, gpointer obj
)
549 #if defined(MONO_CROSS_COMPILE)
550 g_assert_not_reached ();
551 #elif defined(MONO_ARCH_USE_SIGACTION)
552 arm_ucontext
*sigctx
= ctx
;
554 * Handling the exception in the signal handler is problematic, since the original
555 * signal is disabled, and we could run arbitrary code though the debugger. So
556 * resume into the normal stack and do most work there if possible.
558 MonoJitTlsData
*jit_tls
= mono_native_tls_get_value (mono_jit_tls_id
);
559 guint64 sp
= UCONTEXT_REG_SP (sigctx
);
561 /* Pass the ctx parameter in TLS */
562 mono_arch_sigctx_to_monoctx (sigctx
, &jit_tls
->ex_ctx
);
563 /* The others in registers */
564 UCONTEXT_REG_R0 (sigctx
) = (gsize
)obj
;
566 /* Allocate a stack frame */
568 UCONTEXT_REG_SP (sigctx
) = sp
;
570 UCONTEXT_REG_PC (sigctx
) = (gsize
)get_handle_signal_exception_addr ();
571 #ifdef UCONTEXT_REG_CPSR
572 if ((gsize
)UCONTEXT_REG_PC (sigctx
) & 1)
573 /* Transition to thumb */
574 UCONTEXT_REG_CPSR (sigctx
) |= (1 << 5);
576 /* Transition to ARM */
577 UCONTEXT_REG_CPSR (sigctx
) &= ~(1 << 5);
585 mono_arch_sigctx_to_monoctx (ctx
, &mctx
);
587 result
= mono_handle_exception (&mctx
, obj
);
588 /* restore the context so that returning from the signal handler will invoke
591 mono_arch_monoctx_to_sigctx (&mctx
, ctx
);
597 mono_arch_ip_from_context (void *sigctx
)
599 #ifdef MONO_CROSS_COMPILE
600 g_assert_not_reached ();
602 arm_ucontext
*my_uc
= sigctx
;
603 return (void*) UCONTEXT_REG_PC (my_uc
);
608 mono_arch_setup_async_callback (MonoContext
*ctx
, void (*async_cb
)(void *fun
), gpointer user_data
)
610 mgreg_t sp
= (mgreg_t
)MONO_CONTEXT_GET_SP (ctx
);
613 g_assert (!user_data
);
615 /* Allocate a stack frame */
617 MONO_CONTEXT_SET_SP (ctx
, sp
);
618 MONO_CONTEXT_SET_IP (ctx
, async_cb
);
624 * mono_arch_setup_resume_sighandler_ctx:
626 * Setup CTX so execution continues at FUNC.
629 mono_arch_setup_resume_sighandler_ctx (MonoContext
*ctx
, gpointer func
)
631 MONO_CONTEXT_SET_IP (ctx
,func
);
632 if ((mgreg_t
)MONO_CONTEXT_GET_IP (ctx
) & 1)
633 /* Transition to thumb */
634 ctx
->cpsr
|= (1 << 5);
636 /* Transition to ARM */
637 ctx
->cpsr
&= ~(1 << 5);