2 * exceptions-ppc.c: exception support for PowerPC
5 * Dietmar Maurer (dietmar@ximian.com)
6 * Paolo Molaro (lupus@ximian.com)
7 * Andreas Faerber <andreas.faerber@web.de>
9 * (C) 2001 Ximian, Inc.
10 * (C) 2007-2008 Andreas Faerber
22 #include <mono/arch/ppc/ppc-codegen.h>
23 #include <mono/metadata/appdomain.h>
24 #include <mono/metadata/tabledefs.h>
25 #include <mono/metadata/threads.h>
26 #include <mono/metadata/debug-helpers.h>
27 #include <mono/metadata/exception.h>
28 #include <mono/metadata/mono-debug.h>
36 int sc_onstack; // sigstack state to restore
37 int sc_mask; // signal mask to restore
39 int sc_psw; // processor status word
40 int sc_sp; // stack pointer if sc_regs == NULL
41 void *sc_regs; // (kernel private) saved state
46 sigset_t uc_sigmask; // signal mask used by this context
47 stack_t uc_stack; // stack used by this context
48 struct ucontext *uc_link; // pointer to resuming context
49 size_t uc_mcsize; // size of the machine context passed in
50 mcontext_t uc_mcontext; // machine specific context
53 typedef struct ppc_exception_state {
54 unsigned long dar; // Fault registers for coredump
56 unsigned long exception;// number of powerpc exception taken
57 unsigned long pad0; // align to 16 bytes
59 unsigned long pad1[4]; // space in PCB "just in case"
60 } ppc_exception_state_t;
62 typedef struct ppc_vector_state {
63 unsigned long save_vr[32][4];
64 unsigned long save_vscr[4];
65 unsigned int save_pad5[4];
66 unsigned int save_vrvalid; // VRs that have been saved
67 unsigned int save_pad6[7];
70 typedef struct ppc_float_state {
73 unsigned int fpscr_pad; // fpscr is 64 bits, 32 bits of rubbish
74 unsigned int fpscr; // floating point status register
77 typedef struct ppc_thread_state {
78 unsigned int srr0; // Instruction address register (PC)
79 unsigned int srr1; // Machine state register (supervisor)
85 unsigned int cr; // Condition register
86 unsigned int xer; // User's integer exception register
87 unsigned int lr; // Link register
88 unsigned int ctr; // Count register
89 unsigned int mq; // MQ register (601 only)
91 unsigned int vrsave; // Vector Save Register
95 ppc_exception_state_t es;
96 ppc_thread_state_t ss;
98 ppc_vector_state_t vs;
101 typedef struct mcontext * mcontext_t;
103 Linux/PPC instead has:
105 unsigned long _unused[4];
107 unsigned long handler;
108 unsigned long oldmask;
109 struct pt_regs *regs;
112 unsigned long gpr[32];
115 unsigned long orig_gpr3; // Used for restarting system calls
120 unsigned long mq; // 601 only (not used at present)
121 // Used on APUS to hold IPL value.
122 unsigned long trap; // Reason for being here
123 // N.B. for critical exceptions on 4xx, the dar and dsisr
124 // fields are overloaded to hold srr0 and srr1.
125 unsigned long dar; // Fault registers
126 unsigned long dsisr; // on 4xx/Book-E used for ESR
127 unsigned long result; // Result of a system call
130 elf_gregset_t mc_gregs;
131 elf_fpregset_t mc_fregs;
132 unsigned long mc_pad[2];
133 elf_vrregset_t mc_vregs __attribute__((__aligned__(16)));
137 unsigned long uc_flags;
138 struct ucontext *uc_link;
141 struct mcontext *uc_regs; // points to uc_mcontext field
143 // glibc has 1024-bit signal masks, ours are 64-bit
146 struct mcontext uc_mcontext;
149 #define ELF_NGREG 48 // includes nip, msr, lr, etc.
150 #define ELF_NFPREG 33 // includes fpscr
153 typedef unsigned long elf_greg_t;
154 typedef elf_greg_t elf_gregset_t[ELF_NGREG];
156 // Floating point registers
157 typedef double elf_fpreg_t;
158 typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG];
164 #define restore_regs_from_context(ctx_reg,ip_reg,tmp_reg) do { \
166 ppc_ldptr (code, ip_reg, G_STRUCT_OFFSET (MonoContext, sc_ir), ctx_reg); \
167 ppc_load_multiple_regs (code, ppc_r13, G_STRUCT_OFFSET (MonoContext, regs), ctx_reg); \
168 for (reg = 0; reg < MONO_SAVED_FREGS; ++reg) { \
169 ppc_lfd (code, (14 + reg), \
170 G_STRUCT_OFFSET(MonoContext, fregs) + reg * sizeof (gdouble), ctx_reg); \
175 #define setup_context(ctx)
177 #ifdef PPC_USES_FUNCTION_DESCRIPTOR
179 mono_ppc_create_pre_code_ftnptr (guint8 *code)
181 MonoPPCFunctionDescriptor *ftnptr = (MonoPPCFunctionDescriptor*)code;
183 code += sizeof (MonoPPCFunctionDescriptor);
193 * arch_get_restore_context:
195 * Returns a pointer to a method which restores a previously saved sigcontext.
196 * The first argument in r3 is the pointer to the context.
199 mono_arch_get_restore_context (MonoTrampInfo **info, gboolean aot)
201 guint8 *start, *code;
202 int size = MONO_PPC_32_64_CASE (128, 172) + PPC_FTNPTR_SIZE;
203 MonoJumpInfo *ji = NULL;
204 GSList *unwind_ops = NULL;
206 code = start = mono_global_codeman_reserve (size);
208 code = mono_ppc_create_pre_code_ftnptr (code);
209 restore_regs_from_context (ppc_r3, ppc_r4, ppc_r5);
210 /* restore also the stack pointer */
211 ppc_ldptr (code, ppc_sp, G_STRUCT_OFFSET (MonoContext, sc_sp), ppc_r3);
213 /* jump to the saved IP */
214 ppc_mtctr (code, ppc_r4);
215 ppc_bcctr (code, PPC_BR_ALWAYS, 0);
219 g_assert ((code - start) <= size);
220 mono_arch_flush_icache (start, code - start);
223 *info = mono_tramp_info_create ("restore_context", start, code - start, ji, unwind_ops);
228 #define SAVED_REGS_LENGTH (sizeof (gdouble) * MONO_SAVED_FREGS + sizeof (gpointer) * MONO_SAVED_GREGS)
229 #define ALIGN_STACK_FRAME_SIZE(s) (((s) + MONO_ARCH_FRAME_ALIGNMENT - 1) & ~(MONO_ARCH_FRAME_ALIGNMENT - 1))
230 /* The 64 bytes here are for outgoing arguments and a bit of spare.
231 We don't use it all, but it doesn't hurt. */
232 #define REG_SAVE_STACK_FRAME_SIZE (ALIGN_STACK_FRAME_SIZE (SAVED_REGS_LENGTH + PPC_MINIMAL_STACK_SIZE + 64))
235 emit_save_saved_regs (guint8 *code, int pos)
239 for (i = 31; i >= 14; --i) {
240 pos -= sizeof (gdouble);
241 ppc_stfd (code, i, pos, ppc_sp);
243 pos -= sizeof (gpointer) * MONO_SAVED_GREGS;
244 ppc_store_multiple_regs (code, ppc_r13, pos, ppc_sp);
250 * mono_arch_get_call_filter:
252 * Returns a pointer to a method which calls an exception filter. We
253 * also use this function to call finally handlers (we pass NULL as
254 * @exc object in this case).
257 mono_arch_get_call_filter (MonoTrampInfo **info, gboolean aot)
259 guint8 *start, *code;
260 int alloc_size, pos, i;
261 int size = MONO_PPC_32_64_CASE (320, 500) + PPC_FTNPTR_SIZE;
262 MonoJumpInfo *ji = NULL;
263 GSList *unwind_ops = NULL;
265 /* call_filter (MonoContext *ctx, unsigned long eip, gpointer exc) */
266 code = start = mono_global_codeman_reserve (size);
268 code = mono_ppc_create_pre_code_ftnptr (code);
271 ppc_mflr (code, ppc_r0);
272 ppc_stptr (code, ppc_r0, PPC_RET_ADDR_OFFSET, ppc_sp);
274 alloc_size = REG_SAVE_STACK_FRAME_SIZE;
276 /* allocate stack frame and set link from sp in ctx */
277 g_assert ((alloc_size & (MONO_ARCH_FRAME_ALIGNMENT-1)) == 0);
278 ppc_ldptr (code, ppc_r0, G_STRUCT_OFFSET (MonoContext, sc_sp), ppc_r3);
279 ppc_ldptr_indexed (code, ppc_r0, ppc_r0, ppc_r0);
280 ppc_stptr_update (code, ppc_r0, -alloc_size, ppc_sp);
282 code = emit_save_saved_regs (code, alloc_size);
284 /* restore all the regs from ctx (in r3), but not r1, the stack pointer */
285 restore_regs_from_context (ppc_r3, ppc_r6, ppc_r7);
286 /* call handler at eip (r4) and set the first arg with the exception (r5) */
287 ppc_mtctr (code, ppc_r4);
288 ppc_mr (code, ppc_r3, ppc_r5);
289 ppc_bcctrl (code, PPC_BR_ALWAYS, 0);
292 ppc_ldptr (code, ppc_r0, alloc_size + PPC_RET_ADDR_OFFSET, ppc_sp);
293 ppc_mtlr (code, ppc_r0);
295 /* restore all the regs from the stack */
297 for (i = 31; i >= 14; --i) {
298 pos -= sizeof (gdouble);
299 ppc_lfd (code, i, pos, ppc_sp);
301 pos -= sizeof (gpointer) * MONO_SAVED_GREGS;
302 ppc_load_multiple_regs (code, ppc_r13, pos, ppc_sp);
304 ppc_addic (code, ppc_sp, ppc_sp, alloc_size);
307 g_assert ((code - start) < size);
308 mono_arch_flush_icache (start, code - start);
311 *info = mono_tramp_info_create ("call_filter", start, code - start, ji, unwind_ops);
317 mono_ppc_throw_exception (MonoObject *exc, unsigned long eip, unsigned long esp, mgreg_t *int_regs, gdouble *fp_regs, gboolean rethrow)
321 /* adjust eip so that it point into the call instruction */
324 setup_context (&ctx);
326 /*printf ("stack in throw: %p\n", esp);*/
327 MONO_CONTEXT_SET_BP (&ctx, esp);
328 MONO_CONTEXT_SET_IP (&ctx, eip);
329 memcpy (&ctx.regs, int_regs, sizeof (mgreg_t) * MONO_SAVED_GREGS);
330 memcpy (&ctx.fregs, fp_regs, sizeof (double) * MONO_SAVED_FREGS);
332 if (mono_object_isinst (exc, mono_defaults.exception_class)) {
333 MonoException *mono_ex = (MonoException*)exc;
335 mono_ex->stack_trace = NULL;
337 mono_handle_exception (&ctx, exc);
338 mono_restore_context (&ctx);
340 g_assert_not_reached ();
344 * arch_get_throw_exception_generic:
346 * Returns a function pointer which can be used to raise
347 * exceptions. The returned function has the following
348 * signature: void (*func) (MonoException *exc); or
349 * void (*func) (guint32 ex_token, gpointer ip)
353 mono_arch_get_throw_exception_generic (int size, MonoTrampInfo **info, int corlib, gboolean rethrow, gboolean aot)
355 guint8 *start, *code;
357 MonoJumpInfo *ji = NULL;
358 GSList *unwind_ops = NULL;
360 code = start = mono_global_codeman_reserve (size);
362 code = mono_ppc_create_pre_code_ftnptr (code);
366 ppc_mr (code, ppc_r0, ppc_r4);
368 ppc_mflr (code, ppc_r0);
369 ppc_stptr (code, ppc_r0, PPC_RET_ADDR_OFFSET, ppc_sp);
371 alloc_size = REG_SAVE_STACK_FRAME_SIZE;
373 g_assert ((alloc_size & (MONO_ARCH_FRAME_ALIGNMENT-1)) == 0);
374 ppc_stptr_update (code, ppc_sp, -alloc_size, ppc_sp);
376 code = emit_save_saved_regs (code, alloc_size);
380 ppc_mr (code, ppc_r4, ppc_r3);
383 code = mono_arch_emit_load_aotconst (start, code, &ji, MONO_PATCH_INFO_IMAGE, mono_defaults.corlib);
384 ppc_mr (code, ppc_r3, ppc_r12);
385 code = mono_arch_emit_load_aotconst (start, code, &ji, MONO_PATCH_INFO_JIT_ICALL_ADDR, "mono_exception_from_token");
386 #ifdef PPC_USES_FUNCTION_DESCRIPTOR
387 ppc_ldptr (code, ppc_r2, sizeof (gpointer), ppc_r12);
388 ppc_ldptr (code, ppc_r12, 0, ppc_r12);
390 ppc_mtctr (code, ppc_r12);
391 ppc_bcctrl (code, PPC_BR_ALWAYS, 0);
393 ppc_load (code, ppc_r3, (gulong)mono_defaults.corlib);
394 ppc_load_func (code, PPC_CALL_REG, mono_exception_from_token);
395 ppc_mtctr (code, PPC_CALL_REG);
396 ppc_bcctrl (code, PPC_BR_ALWAYS, 0);
400 /* call throw_exception (exc, ip, sp, int_regs, fp_regs) */
402 ppc_ldptr (code, ppc_r5, 0, ppc_sp);
403 /* exc is already in place in r3 */
405 ppc_ldptr (code, ppc_r4, PPC_RET_ADDR_OFFSET, ppc_r5);
407 ppc_mr (code, ppc_r4, ppc_r0); /* caller ip */
408 /* pointer to the saved fp regs */
409 pos = alloc_size - sizeof (gdouble) * MONO_SAVED_FREGS;
410 ppc_addi (code, ppc_r7, ppc_sp, pos);
411 /* pointer to the saved int regs */
412 pos -= sizeof (gpointer) * MONO_SAVED_GREGS;
413 ppc_addi (code, ppc_r6, ppc_sp, pos);
414 ppc_li (code, ppc_r8, rethrow);
417 // This can be called from runtime code, which can't guarantee that
418 // r30 contains the got address.
419 // So emit the got address loading code too
420 code = mono_arch_emit_load_got_addr (start, code, NULL, &ji);
421 code = mono_arch_emit_load_aotconst (start, code, &ji, MONO_PATCH_INFO_JIT_ICALL_ADDR, "mono_ppc_throw_exception");
422 #ifdef PPC_USES_FUNCTION_DESCRIPTOR
423 ppc_ldptr (code, ppc_r2, sizeof (gpointer), ppc_r12);
424 ppc_ldptr (code, ppc_r12, 0, ppc_r12);
426 ppc_mtctr (code, ppc_r12);
427 ppc_bcctrl (code, PPC_BR_ALWAYS, 0);
429 ppc_load_func (code, PPC_CALL_REG, mono_ppc_throw_exception);
430 ppc_mtctr (code, PPC_CALL_REG);
431 ppc_bcctrl (code, PPC_BR_ALWAYS, 0);
433 /* we should never reach this breakpoint */
435 g_assert ((code - start) <= size);
436 mono_arch_flush_icache (start, code - start);
439 *info = mono_tramp_info_create (corlib ? "throw_corlib_exception" : (rethrow ? "rethrow_exception" : "throw_exception"), start, code - start, ji, unwind_ops);
445 * mono_arch_get_rethrow_exception:
447 * Returns a function pointer which can be used to rethrow
448 * exceptions. The returned function has the following
449 * signature: void (*func) (MonoException *exc);
453 mono_arch_get_rethrow_exception (MonoTrampInfo **info, gboolean aot)
455 int size = MONO_PPC_32_64_CASE (132, 224) + PPC_FTNPTR_SIZE;
459 return mono_arch_get_throw_exception_generic (size, info, FALSE, TRUE, aot);
463 * arch_get_throw_exception:
465 * Returns a function pointer which can be used to raise
466 * exceptions. The returned function has the following
467 * signature: void (*func) (MonoException *exc);
468 * For example to raise an arithmetic exception you can use:
470 * x86_push_imm (code, mono_get_exception_arithmetic ());
471 * x86_call_code (code, arch_get_throw_exception ());
475 mono_arch_get_throw_exception (MonoTrampInfo **info, gboolean aot)
477 int size = MONO_PPC_32_64_CASE (132, 224) + PPC_FTNPTR_SIZE;
481 return mono_arch_get_throw_exception_generic (size, info, FALSE, FALSE, aot);
485 * mono_arch_get_throw_corlib_exception:
487 * Returns a function pointer which can be used to raise
488 * corlib exceptions. The returned function has the following
489 * signature: void (*func) (guint32 ex_token, guint32 offset);
490 * On PPC, we pass the ip instead of the offset
493 mono_arch_get_throw_corlib_exception (MonoTrampInfo **info, gboolean aot)
495 int size = MONO_PPC_32_64_CASE (168, 304) + PPC_FTNPTR_SIZE;
499 return mono_arch_get_throw_exception_generic (size, info, TRUE, FALSE, aot);
503 * mono_arch_find_jit_info:
505 * See exceptions-amd64.c for docs.
508 mono_arch_find_jit_info (MonoDomain *domain, MonoJitTlsData *jit_tls,
509 MonoJitInfo *ji, MonoContext *ctx,
510 MonoContext *new_ctx, MonoLMF **lmf,
511 mgreg_t **save_locations,
512 StackFrameInfo *frame)
514 gpointer ip = MONO_CONTEXT_GET_IP (ctx);
515 MonoPPCStackFrame *sframe;
517 memset (frame, 0, sizeof (StackFrameInfo));
521 setup_context (new_ctx);
525 mgreg_t regs [ppc_lr + 1];
527 guint32 unwind_info_len;
530 frame->type = FRAME_TYPE_MANAGED;
532 unwind_info = mono_jinfo_get_unwind_info (ji, &unwind_info_len);
534 sframe = (MonoPPCStackFrame*)MONO_CONTEXT_GET_SP (ctx);
535 MONO_CONTEXT_SET_BP (new_ctx, sframe->sp);
536 if (jinfo_get_method (ji)->save_lmf) {
537 /* sframe->sp points just past the end of the LMF */
538 guint8 *lmf_addr = (guint8*)sframe->sp - sizeof (MonoLMF);
539 memcpy (&new_ctx->fregs, lmf_addr + G_STRUCT_OFFSET (MonoLMF, fregs), sizeof (double) * MONO_SAVED_FREGS);
540 memcpy (&new_ctx->regs, lmf_addr + G_STRUCT_OFFSET (MonoLMF, iregs), sizeof (mgreg_t) * MONO_SAVED_GREGS);
541 /* the calling IP is in the parent frame */
542 sframe = (MonoPPCStackFrame*)sframe->sp;
543 /* we substract 4, so that the IP points into the call instruction */
544 MONO_CONTEXT_SET_IP (new_ctx, sframe->lr - 4);
546 regs [ppc_lr] = ctx->sc_ir;
547 regs [ppc_sp] = ctx->sc_sp;
548 for (i = 0; i < MONO_SAVED_GREGS; ++i)
549 regs [ppc_r13 + i] = ctx->regs [i];
551 mono_unwind_frame (unwind_info, unwind_info_len, ji->code_start,
552 (guint8*)ji->code_start + ji->code_size,
553 ip, NULL, regs, ppc_lr + 1,
554 save_locations, MONO_MAX_IREGS, &cfa);
556 /* we substract 4, so that the IP points into the call instruction */
557 MONO_CONTEXT_SET_IP (new_ctx, regs [ppc_lr] - 4);
558 MONO_CONTEXT_SET_BP (new_ctx, cfa);
560 for (i = 0; i < MONO_SAVED_GREGS; ++i)
561 new_ctx->regs [i] = regs [ppc_r13 + i];
567 if ((ji = mini_jit_info_table_find (domain, (gpointer)(*lmf)->eip, NULL))) {
572 /* Trampoline lmf frame */
573 frame->method = (*lmf)->method;
576 /*sframe = (MonoPPCStackFrame*)MONO_CONTEXT_GET_SP (ctx);
577 MONO_CONTEXT_SET_BP (new_ctx, sframe->sp);
578 MONO_CONTEXT_SET_IP (new_ctx, sframe->lr);*/
579 MONO_CONTEXT_SET_BP (new_ctx, (*lmf)->ebp);
580 MONO_CONTEXT_SET_IP (new_ctx, (*lmf)->eip);
581 memcpy (&new_ctx->regs, (*lmf)->iregs, sizeof (mgreg_t) * MONO_SAVED_GREGS);
582 memcpy (&new_ctx->fregs, (*lmf)->fregs, sizeof (double) * MONO_SAVED_FREGS);
585 frame->type = FRAME_TYPE_MANAGED_TO_NATIVE;
587 /* FIXME: what about trampoline LMF frames? see exceptions-x86.c */
589 *lmf = (*lmf)->previous_lmf;
598 mono_arch_ip_from_context (void *sigctx)
600 #ifdef MONO_CROSS_COMPILE
601 g_assert_not_reached ();
603 os_ucontext *uc = sigctx;
604 return (gpointer)UCONTEXT_REG_NIP(uc);
609 mono_ppc_set_func_into_sigctx (void *sigctx, void *func)
611 #ifdef MONO_CROSS_COMPILE
612 g_assert_not_reached ();
613 #elif defined(PPC_USES_FUNCTION_DESCRIPTOR)
614 /* Have to set both the ip and the TOC reg */
615 os_ucontext *uc = sigctx;
617 UCONTEXT_REG_NIP(uc) = ((gsize*)func) [0];
618 UCONTEXT_REG_Rn (uc, 2) = ((gsize*)func)[1];
620 g_assert_not_reached ();
625 altstack_handle_and_restore (void *sigctx, gpointer obj)
629 mono_sigctx_to_monoctx (sigctx, &mctx);
630 mono_handle_exception (&mctx, obj);
631 mono_restore_context (&mctx);
635 mono_arch_handle_altstack_exception (void *sigctx, gpointer fault_addr, gboolean stack_ovf)
637 #ifdef MONO_CROSS_COMPILE
638 g_assert_not_reached ();
640 #ifdef MONO_ARCH_USE_SIGACTION
641 os_ucontext *uc = (ucontext_t*)sigctx;
642 os_ucontext *uc_copy;
643 MonoJitInfo *ji = mini_jit_info_table_find (mono_domain_get (), mono_arch_ip_from_context (sigctx), NULL);
649 /* we don't do much now, but we can warn the user with a useful message */
650 fprintf (stderr, "Stack overflow: IP: %p, SP: %p\n", mono_arch_ip_from_context (sigctx), (gpointer)UCONTEXT_REG_Rn(uc, 1));
651 if (ji && jinfo_get_method (ji))
652 method = mono_method_full_name (jinfo_get_method (ji), TRUE);
654 method = "Unmanaged";
655 fprintf (stderr, "At %s\n", method);
659 mono_handle_native_sigsegv (SIGSEGV, sigctx);
660 /* setup a call frame on the real stack so that control is returned there
661 * and exception handling can continue.
662 * The frame looks like:
665 * 224 is the size of the red zone
667 frame_size = sizeof (ucontext_t) + sizeof (gpointer) * 16 + 224;
670 sp = (gpointer)(UCONTEXT_REG_Rn(uc, 1) & ~15);
671 sp = (gpointer)((char*)sp - frame_size);
672 /* may need to adjust pointers in the new struct copy, depending on the OS */
673 uc_copy = (ucontext_t*)(sp + 16);
674 memcpy (uc_copy, uc, sizeof (os_ucontext));
675 #if defined(__linux__) && !defined(__mono_ppc64__)
676 uc_copy->uc_mcontext.uc_regs = (gpointer)((char*)uc_copy + ((char*)uc->uc_mcontext.uc_regs - (char*)uc));
678 g_assert (mono_arch_ip_from_context (uc) == mono_arch_ip_from_context (uc_copy));
679 /* at the return form the signal handler execution starts in altstack_handle_and_restore() */
680 UCONTEXT_REG_LNK(uc) = UCONTEXT_REG_NIP(uc);
681 #ifdef PPC_USES_FUNCTION_DESCRIPTOR
683 MonoPPCFunctionDescriptor *handler_ftnptr = (MonoPPCFunctionDescriptor*)altstack_handle_and_restore;
685 UCONTEXT_REG_NIP(uc) = (gulong)handler_ftnptr->code;
686 UCONTEXT_REG_Rn(uc, 2) = (gulong)handler_ftnptr->toc;
689 UCONTEXT_REG_NIP(uc) = (unsigned long)altstack_handle_and_restore;
691 UCONTEXT_REG_Rn(uc, 1) = (unsigned long)sp;
692 UCONTEXT_REG_Rn(uc, PPC_FIRST_ARG_REG) = (unsigned long)(sp + 16);
693 UCONTEXT_REG_Rn(uc, PPC_FIRST_ARG_REG + 1) = 0;
694 UCONTEXT_REG_Rn(uc, PPC_FIRST_ARG_REG + 2) = 0;
697 #endif /* !MONO_CROSS_COMPILE */
703 * Called by resuming from a signal handler.
706 handle_signal_exception (gpointer obj)
708 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
711 memcpy (&ctx, &jit_tls->ex_ctx, sizeof (MonoContext));
713 mono_handle_exception (&ctx, obj);
715 mono_restore_context (&ctx);
719 setup_ucontext_return (void *uc, gpointer func)
721 #if !defined(MONO_CROSS_COMPILE)
722 UCONTEXT_REG_LNK(uc) = UCONTEXT_REG_NIP(uc);
723 #ifdef PPC_USES_FUNCTION_DESCRIPTOR
725 MonoPPCFunctionDescriptor *handler_ftnptr = (MonoPPCFunctionDescriptor*)func;
727 UCONTEXT_REG_NIP(uc) = (gulong)handler_ftnptr->code;
728 UCONTEXT_REG_Rn(uc, 2) = (gulong)handler_ftnptr->toc;
731 UCONTEXT_REG_NIP(uc) = (unsigned long)func;
737 mono_arch_handle_exception (void *ctx, gpointer obj)
739 #if defined(MONO_ARCH_USE_SIGACTION) && defined(UCONTEXT_REG_Rn)
741 * Handling the exception in the signal handler is problematic, since the original
742 * signal is disabled, and we could run arbitrary code though the debugger. So
743 * resume into the normal stack and do most work there if possible.
745 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
751 /* Pass the ctx parameter in TLS */
752 mono_sigctx_to_monoctx (sigctx, &jit_tls->ex_ctx);
753 /* The others in registers */
754 UCONTEXT_REG_Rn (sigctx, PPC_FIRST_ARG_REG) = (gsize)obj;
756 /* Allocate a stack frame below the red zone */
757 /* Similar to mono_arch_handle_altstack_exception () */
761 sp = (mgreg_t)(UCONTEXT_REG_Rn(uc, 1) & ~15);
762 sp = (mgreg_t)(sp - frame_size);
763 UCONTEXT_REG_Rn(uc, 1) = (mgreg_t)sp;
764 setup_ucontext_return (uc, handle_signal_exception);
771 mono_sigctx_to_monoctx (ctx, &mctx);
773 result = mono_handle_exception (&mctx, obj);
774 /* restore the context so that returning from the signal handler will invoke
777 mono_monoctx_to_sigctx (&mctx, ctx);