/* * exceptions-ppc.c: exception support for PowerPC * * Authors: * Dietmar Maurer (dietmar@ximian.com) * Paolo Molaro (lupus@ximian.com) * * (C) 2001 Ximian, Inc. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include "mini.h" #include "mini-ppc.h" /* struct sigcontext { int sc_onstack; // sigstack state to restore int sc_mask; // signal mask to restore int sc_ir; // pc int sc_psw; // processor status word int sc_sp; // stack pointer if sc_regs == NULL void *sc_regs; // (kernel private) saved state }; struct ucontext { int uc_onstack; sigset_t uc_sigmask; // signal mask used by this context stack_t uc_stack; // stack used by this context struct ucontext *uc_link; // pointer to resuming context size_t uc_mcsize; // size of the machine context passed in mcontext_t uc_mcontext; // machine specific context }; typedef struct ppc_exception_state { unsigned long dar; // Fault registers for coredump unsigned long dsisr; unsigned long exception;// number of powerpc exception taken unsigned long pad0; // align to 16 bytes unsigned long pad1[4]; // space in PCB "just in case" } ppc_exception_state_t; typedef struct ppc_vector_state { unsigned long save_vr[32][4]; unsigned long save_vscr[4]; unsigned int save_pad5[4]; unsigned int save_vrvalid; // VRs that have been saved unsigned int save_pad6[7]; } ppc_vector_state_t; typedef struct ppc_float_state { double fpregs[32]; unsigned int fpscr_pad; // fpscr is 64 bits, 32 bits of rubbish unsigned int fpscr; // floating point status register } ppc_float_state_t; typedef struct ppc_thread_state { unsigned int srr0; // Instruction address register (PC) unsigned int srr1; // Machine state register (supervisor) unsigned int r0; unsigned int r1; unsigned int r2; ... unsigned int r31; unsigned int cr; // Condition register unsigned int xer; // User's integer exception register unsigned int lr; // Link register unsigned int ctr; // Count register unsigned int mq; // MQ register (601 only) unsigned int vrsave; // Vector Save Register } ppc_thread_state_t; struct mcontext { ppc_exception_state_t es; ppc_thread_state_t ss; ppc_float_state_t fs; ppc_vector_state_t vs; }; typedef struct mcontext * mcontext_t; Linux/PPC instead has: struct sigcontext { unsigned long _unused[4]; int signal; unsigned long handler; unsigned long oldmask; struct pt_regs *regs; }; struct pt_regs { unsigned long gpr[32]; unsigned long nip; unsigned long msr; unsigned long orig_gpr3; // Used for restarting system calls unsigned long ctr; unsigned long link; unsigned long xer; unsigned long ccr; unsigned long mq; // 601 only (not used at present) // Used on APUS to hold IPL value. unsigned long trap; // Reason for being here // N.B. for critical exceptions on 4xx, the dar and dsisr // fields are overloaded to hold srr0 and srr1. unsigned long dar; // Fault registers unsigned long dsisr; // on 4xx/Book-E used for ESR unsigned long result; // Result of a system call }; struct mcontext { elf_gregset_t mc_gregs; elf_fpregset_t mc_fregs; unsigned long mc_pad[2]; elf_vrregset_t mc_vregs __attribute__((__aligned__(16))); }; struct ucontext { unsigned long uc_flags; struct ucontext *uc_link; stack_t uc_stack; int uc_pad[7]; struct mcontext *uc_regs; // points to uc_mcontext field sigset_t uc_sigmask; // glibc has 1024-bit signal masks, ours are 64-bit int uc_maskext[30]; int uc_pad2[3]; struct mcontext uc_mcontext; }; #define ELF_NGREG 48 // includes nip, msr, lr, etc. #define ELF_NFPREG 33 // includes fpscr // General registers typedef unsigned long elf_greg_t; typedef elf_greg_t elf_gregset_t[ELF_NGREG]; // Floating point registers typedef double elf_fpreg_t; typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG]; */ #define restore_regs_from_context(ctx_reg,ip_reg,tmp_reg) do { \ int reg; \ ppc_lwz (code, ip_reg, G_STRUCT_OFFSET (MonoContext, sc_ir), ctx_reg); \ ppc_lmw (code, ppc_r13, ctx_reg, G_STRUCT_OFFSET (MonoContext, regs)); \ for (reg = 0; reg < MONO_SAVED_FREGS; ++reg) { \ ppc_lfd (code, (14 + reg), G_STRUCT_OFFSET(MonoLMF, fregs) + reg * sizeof (gdouble), ctx_reg); \ } \ } while (0) /* nothing to do */ #define setup_context(ctx) /* * arch_get_restore_context: * * Returns a pointer to a method which restores a previously saved sigcontext. * The first argument in r3 is the pointer to the context. */ gpointer mono_arch_get_restore_context (void) { guint8 *code; static guint8 *start = NULL; if (start) return start; code = start = mono_global_codeman_reserve (128); restore_regs_from_context (ppc_r3, ppc_r4, ppc_r5); /* restore also the stack pointer */ ppc_lwz (code, ppc_sp, G_STRUCT_OFFSET (MonoContext, sc_sp), ppc_r3); //ppc_break (code); /* jump to the saved IP */ ppc_mtctr (code, ppc_r4); ppc_bcctr (code, PPC_BR_ALWAYS, 0); /* never reached */ ppc_break (code); g_assert ((code - start) < 128); mono_arch_flush_icache (start, code - start); return start; } /* * mono_arch_get_call_filter: * * Returns a pointer to a method which calls an exception filter. We * also use this function to call finally handlers (we pass NULL as * @exc object in this case). */ gpointer mono_arch_get_call_filter (void) { static guint8 *start = NULL; guint8 *code; int alloc_size, pos, i; if (start) return start; /* call_filter (MonoContext *ctx, unsigned long eip, gpointer exc) */ code = start = mono_global_codeman_reserve (320); /* save all the regs on the stack */ pos = 0; for (i = 31; i >= 14; --i) { pos += sizeof (gdouble); ppc_stfd (code, i, -pos, ppc_sp); } pos += sizeof (gulong) * MONO_SAVED_GREGS; ppc_stmw (code, ppc_r13, ppc_sp, -pos); ppc_mflr (code, ppc_r0); ppc_stw (code, ppc_r0, PPC_RET_ADDR_OFFSET, ppc_sp); alloc_size = PPC_MINIMAL_STACK_SIZE + pos + 64; // align to PPC_STACK_ALIGNMENT bytes alloc_size += PPC_STACK_ALIGNMENT - 1; alloc_size &= ~(PPC_STACK_ALIGNMENT - 1); /* allocate stack frame and set link from sp in ctx */ g_assert ((alloc_size & (PPC_STACK_ALIGNMENT-1)) == 0); ppc_lwz (code, ppc_r0, G_STRUCT_OFFSET (MonoContext, sc_sp), ppc_r3); ppc_lwzx (code, ppc_r0, ppc_r0, ppc_r0); ppc_stwu (code, ppc_r0, -alloc_size, ppc_sp); /* restore all the regs from ctx (in r3), but not r1, the stack pointer */ restore_regs_from_context (ppc_r3, ppc_r6, ppc_r7); /* call handler at eip (r4) and set the first arg with the exception (r5) */ ppc_mtctr (code, ppc_r4); ppc_mr (code, ppc_r3, ppc_r5); ppc_bcctrl (code, PPC_BR_ALWAYS, 0); /* epilog */ ppc_lwz (code, ppc_r0, alloc_size + PPC_RET_ADDR_OFFSET, ppc_sp); ppc_mtlr (code, ppc_r0); ppc_addic (code, ppc_sp, ppc_sp, alloc_size); /* restore all the regs from the stack */ pos = 0; for (i = 31; i >= 14; --i) { pos += sizeof (double); ppc_lfd (code, i, -pos, ppc_sp); } pos += sizeof (gulong) * MONO_SAVED_GREGS; ppc_lmw (code, ppc_r13, ppc_sp, -pos); ppc_blr (code); g_assert ((code - start) < 320); mono_arch_flush_icache (start, code - start); return start; } static void throw_exception (MonoObject *exc, unsigned long eip, unsigned long esp, gulong *int_regs, gdouble *fp_regs, gboolean rethrow) { static void (*restore_context) (MonoContext *); MonoContext ctx; if (!restore_context) restore_context = mono_arch_get_restore_context (); /* adjust eip so that it point into the call instruction */ eip -= 4; setup_context (&ctx); /*printf ("stack in throw: %p\n", esp);*/ MONO_CONTEXT_SET_BP (&ctx, esp); MONO_CONTEXT_SET_IP (&ctx, eip); memcpy (&ctx.regs, int_regs, sizeof (gulong) * MONO_SAVED_GREGS); memcpy (&ctx.fregs, fp_regs, sizeof (double) * MONO_SAVED_FREGS); if (mono_object_isinst (exc, mono_defaults.exception_class)) { MonoException *mono_ex = (MonoException*)exc; if (!rethrow) mono_ex->stack_trace = NULL; } mono_handle_exception (&ctx, exc, (gpointer)eip, FALSE); restore_context (&ctx); g_assert_not_reached (); } /** * arch_get_throw_exception_generic: * * Returns a function pointer which can be used to raise * exceptions. The returned function has the following * signature: void (*func) (MonoException *exc); or * void (*func) (char *exc_name); * */ static gpointer mono_arch_get_throw_exception_generic (guint8 *start, int size, int by_name, gboolean rethrow) { guint8 *code; int alloc_size, pos, i; code = start; /* save all the regs on the stack */ pos = 0; for (i = 31; i >= 14; --i) { pos += sizeof (gdouble); ppc_stfd (code, i, -pos, ppc_sp); } pos += sizeof (gulong) * MONO_SAVED_GREGS; ppc_stmw (code, ppc_r13, ppc_sp, -pos); ppc_mflr (code, ppc_r0); ppc_stw (code, ppc_r0, PPC_RET_ADDR_OFFSET, ppc_sp); alloc_size = PPC_MINIMAL_STACK_SIZE + pos + 64; // align to PPC_STACK_ALIGNMENT bytes alloc_size += PPC_STACK_ALIGNMENT - 1; alloc_size &= ~(PPC_STACK_ALIGNMENT - 1); g_assert ((alloc_size & (PPC_STACK_ALIGNMENT-1)) == 0); ppc_stwu (code, ppc_sp, -alloc_size, ppc_sp); //ppc_break (code); if (by_name) { ppc_mr (code, ppc_r5, ppc_r3); ppc_load (code, ppc_r3, (guint32)mono_defaults.corlib); ppc_load (code, ppc_r4, "System"); ppc_load (code, ppc_r0, mono_exception_from_name); ppc_mtctr (code, ppc_r0); ppc_bcctrl (code, PPC_BR_ALWAYS, 0); } /* call throw_exception (exc, ip, sp, int_regs, fp_regs) */ /* caller sp */ ppc_lwz (code, ppc_r5, 0, ppc_sp); /* exc is already in place in r3 */ if (by_name) ppc_lwz (code, ppc_r4, PPC_RET_ADDR_OFFSET, ppc_r5); else ppc_mr (code, ppc_r4, ppc_r0); /* caller ip */ /* pointer to the saved fp regs */ pos = alloc_size - sizeof (double) * MONO_SAVED_FREGS; ppc_addi (code, ppc_r7, ppc_sp, pos); /* pointer to the saved int regs */ pos -= sizeof (gulong) * MONO_SAVED_GREGS; ppc_addi (code, ppc_r6, ppc_sp, pos); ppc_li (code, ppc_r8, rethrow); ppc_load (code, ppc_r0, throw_exception); ppc_mtctr (code, ppc_r0); ppc_bcctrl (code, PPC_BR_ALWAYS, 0); /* we should never reach this breakpoint */ ppc_break (code); g_assert ((code - start) < size); mono_arch_flush_icache (start, code - start); return start; } /** * mono_arch_get_rethrow_exception: * * Returns a function pointer which can be used to rethrow * exceptions. The returned function has the following * signature: void (*func) (MonoException *exc); * */ gpointer mono_arch_get_rethrow_exception (void) { static guint8 *start = NULL; static int inited = 0; if (inited) return start; start = mono_global_codeman_reserve (132); mono_arch_get_throw_exception_generic (start, 132, FALSE, TRUE); inited = 1; return start; } /** * arch_get_throw_exception: * * Returns a function pointer which can be used to raise * exceptions. The returned function has the following * signature: void (*func) (MonoException *exc); * For example to raise an arithmetic exception you can use: * * x86_push_imm (code, mono_get_exception_arithmetic ()); * x86_call_code (code, arch_get_throw_exception ()); * */ gpointer mono_arch_get_throw_exception (void) { static guint8 *start = NULL; static int inited = 0; if (inited) return start; start = mono_global_codeman_reserve (132); mono_arch_get_throw_exception_generic (start, 132, FALSE, FALSE); inited = 1; return start; } /** * arch_get_throw_exception_by_name: * * Returns a function pointer which can be used to raise * corlib exceptions. The returned function has the following * signature: void (*func) (char *exc_name); * For example to raise an arithmetic exception you can use: * * x86_push_imm (code, "ArithmeticException"); * x86_call_code (code, arch_get_throw_exception_by_name ()); * */ gpointer mono_arch_get_throw_exception_by_name (void) { static guint8 *start = NULL; static int inited = 0; if (inited) return start; start = mono_global_codeman_reserve (168); mono_arch_get_throw_exception_generic (start, 168, TRUE, FALSE); inited = 1; return start; } static MonoArray * glist_to_array (GList *list, MonoClass *eclass) { MonoDomain *domain = mono_domain_get (); MonoArray *res; int len, i; if (!list) return NULL; len = g_list_length (list); res = mono_array_new (domain, eclass, len); for (i = 0; list; list = list->next, i++) mono_array_set (res, gpointer, i, list->data); return res; } /* mono_arch_find_jit_info: * * This function is used to gather information from @ctx. It return the * MonoJitInfo of the corresponding function, unwinds one stack frame and * stores the resulting context into @new_ctx. It also stores a string * describing the stack location into @trace (if not NULL), and modifies * the @lmf if necessary. @native_offset return the IP offset from the * start of the function or -1 if that info is not available. */ MonoJitInfo * mono_arch_find_jit_info (MonoDomain *domain, MonoJitTlsData *jit_tls, MonoJitInfo *res, MonoJitInfo *prev_ji, MonoContext *ctx, MonoContext *new_ctx, MonoLMF **lmf, gboolean *managed) { MonoJitInfo *ji; gpointer ip = MONO_CONTEXT_GET_IP (ctx); MonoPPCStackFrame *sframe; /* Avoid costly table lookup during stack overflow */ if (prev_ji && (ip > prev_ji->code_start && ((guint8*)ip < ((guint8*)prev_ji->code_start) + prev_ji->code_size))) ji = prev_ji; else ji = mono_jit_info_table_find (domain, ip); if (managed) *managed = FALSE; if (ji != NULL) { gint32 address; int offset, i; *new_ctx = *ctx; setup_context (new_ctx); if (*lmf && (MONO_CONTEXT_GET_SP (ctx) >= (gpointer)(*lmf)->ebp)) { /* remove any unused lmf */ *lmf = (*lmf)->previous_lmf; } address = (char *)ip - (char *)ji->code_start; if (managed) if (!ji->method->wrapper_type) *managed = TRUE; sframe = (MonoPPCStackFrame*)MONO_CONTEXT_GET_SP (ctx); MONO_CONTEXT_SET_BP (new_ctx, sframe->sp); if (ji->method->save_lmf) { memcpy (&new_ctx->fregs, (char*)sframe->sp - sizeof (double) * MONO_SAVED_FREGS, sizeof (double) * MONO_SAVED_FREGS); memcpy (&new_ctx->regs, (char*)sframe->sp - sizeof (double) * MONO_SAVED_FREGS - sizeof (gulong) * MONO_SAVED_GREGS, sizeof (gulong) * MONO_SAVED_GREGS); } else if (ji->used_regs) { /* keep updated with emit_prolog in mini-ppc.c */ offset = 0; /* FIXME handle floating point args for (i = 31; i >= 14; --i) { if (ji->used_fregs & (1 << i)) { offset += sizeof (double); new_ctx->fregs [i - 14] = *(gulong*)((char*)sframe->sp - offset); } }*/ for (i = 31; i >= 13; --i) { if (ji->used_regs & (1 << i)) { offset += sizeof (gulong); new_ctx->regs [i - 13] = *(gulong*)((char*)sframe->sp - offset); } } } /* the calling IP is in the parent frame */ sframe = (MonoPPCStackFrame*)sframe->sp; /* we substract 4, so that the IP points into the call instruction */ MONO_CONTEXT_SET_IP (new_ctx, sframe->lr - 4); return ji; } else if (*lmf) { *new_ctx = *ctx; setup_context (new_ctx); if ((ji = mono_jit_info_table_find (domain, (gpointer)(*lmf)->eip))) { } else { if (!(*lmf)->method) return (gpointer)-1; memset (res, 0, sizeof (MonoJitInfo)); res->method = (*lmf)->method; } /*sframe = (MonoPPCStackFrame*)MONO_CONTEXT_GET_SP (ctx); MONO_CONTEXT_SET_BP (new_ctx, sframe->sp); MONO_CONTEXT_SET_IP (new_ctx, sframe->lr);*/ MONO_CONTEXT_SET_BP (new_ctx, (*lmf)->ebp); MONO_CONTEXT_SET_IP (new_ctx, (*lmf)->eip); memcpy (&new_ctx->regs, (*lmf)->iregs, sizeof (gulong) * MONO_SAVED_GREGS); memcpy (&new_ctx->fregs, (*lmf)->fregs, sizeof (double) * MONO_SAVED_FREGS); /* FIXME: what about trampoline LMF frames? see exceptions-x86.c */ *lmf = (*lmf)->previous_lmf; return ji ? ji : res; } return NULL; } /* * This is the function called from the signal handler */ void mono_arch_sigctx_to_monoctx (void *ctx, MonoContext *mctx) { os_ucontext *uc = ctx; mctx->sc_ir = UCONTEXT_REG_NIP(uc); mctx->sc_sp = UCONTEXT_REG_Rn(uc, 1); memcpy (&mctx->regs, &UCONTEXT_REG_Rn(uc, 13), sizeof (gulong) * MONO_SAVED_GREGS); memcpy (&mctx->fregs, &UCONTEXT_REG_FPRn(uc, 14), sizeof (double) * MONO_SAVED_FREGS); } void mono_arch_monoctx_to_sigctx (MonoContext *mctx, void *ctx) { os_ucontext *uc = ctx; UCONTEXT_REG_NIP(uc) = mctx->sc_ir; UCONTEXT_REG_Rn(uc, 1) = mctx->sc_sp; memcpy (&UCONTEXT_REG_Rn(uc, 13), &mctx->regs, sizeof (gulong) * MONO_SAVED_GREGS); memcpy (&UCONTEXT_REG_FPRn(uc, 14), &mctx->fregs, sizeof (double) * MONO_SAVED_FREGS); } gpointer mono_arch_ip_from_context (void *sigctx) { os_ucontext *uc = sigctx; return (gpointer)UCONTEXT_REG_NIP(uc); } #ifndef __APPLE__ static void altstack_handle_and_restore (void *sigctx, gpointer obj, gboolean test_only) { void (*restore_context) (MonoContext *); MonoContext mctx; restore_context = mono_arch_get_restore_context (); mono_arch_sigctx_to_monoctx (sigctx, &mctx); mono_handle_exception (&mctx, obj, (gpointer)mctx.sc_ir, test_only); restore_context (&mctx); } void mono_arch_handle_altstack_exception (void *sigctx, gpointer fault_addr, gboolean stack_ovf) { #ifdef MONO_ARCH_USE_SIGACTION ucontext_t *uc = (ucontext_t*)sigctx; ucontext_t *uc_copy; MonoJitInfo *ji = mono_jit_info_table_find (mono_domain_get (), mono_arch_ip_from_context (sigctx)); gpointer *sp; int frame_size; if (stack_ovf) { const char *method; /* we don't do much now, but we can warn the user with a useful message */ fprintf (stderr, "Stack overflow: IP: %p, SP: %p\n", mono_arch_ip_from_context (sigctx), (gpointer)UCONTEXT_REG_Rn(uc, 1)); if (ji && ji->method) method = mono_method_full_name (ji->method, TRUE); else method = "Unmanaged"; fprintf (stderr, "At %s\n", method); abort (); } if (!ji) mono_handle_native_sigsegv (SIGSEGV, sigctx); /* setup a call frame on the real stack so that control is returned there * and exception handling can continue. * The frame looks like: * ucontext struct * ... * 224 is the size of the red zone */ frame_size = sizeof (ucontext_t) + sizeof (gpointer) * 16 + 224; frame_size += 15; frame_size &= ~15; sp = (gpointer)(UCONTEXT_REG_Rn(uc, 1) & ~15); sp = (gpointer)((char*)sp - frame_size); /* may need to adjust pointers in the new struct copy, depending on the OS */ uc_copy = (ucontext_t*)(sp + 16); memcpy (uc_copy, uc, sizeof (os_ucontext)); #ifdef __linux__ uc_copy->uc_mcontext.uc_regs = (gpointer)((char*)uc_copy + ((char*)uc->uc_mcontext.uc_regs - (char*)uc)); #endif g_assert (mono_arch_ip_from_context (uc) == mono_arch_ip_from_context (uc_copy)); /* at the return form the signal handler execution starts in altstack_handle_and_restore() */ UCONTEXT_REG_LNK(uc) = UCONTEXT_REG_NIP(uc); UCONTEXT_REG_NIP(uc) = (unsigned long)altstack_handle_and_restore; UCONTEXT_REG_Rn(uc, 1) = (unsigned long)sp; UCONTEXT_REG_Rn(uc, PPC_FIRST_ARG_REG) = (unsigned long)(sp + 16); UCONTEXT_REG_Rn(uc, PPC_FIRST_ARG_REG + 1) = 0; UCONTEXT_REG_Rn(uc, PPC_FIRST_ARG_REG + 2) = 0; #endif } #endif gboolean mono_arch_handle_exception (void *ctx, gpointer obj, gboolean test_only) { MonoContext mctx; gboolean result; mono_arch_sigctx_to_monoctx (ctx, &mctx); result = mono_handle_exception (&mctx, obj, (gpointer)mctx.sc_ir, test_only); /* restore the context so that returning from the signal handler will invoke * the catch clause */ mono_arch_monoctx_to_sigctx (&mctx, ctx); return result; } gboolean mono_arch_has_unwind_info (gconstpointer addr) { return FALSE; }