/* $OpenBSD: trap.c,v 1.18 1998/03/01 15:00:59 niklas Exp $ */ /* $NetBSD: trap.c,v 1.19 1996/11/27 01:28:30 cgd Exp $ */ /* * Copyright (c) 1994, 1995, 1996 Carnegie-Mellon University. * All rights reserved. * * Author: Chris G. Demetriou * * Permission to use, copy, modify and distribute this software and * its documentation is hereby granted, provided that both the copyright * notice and this permission notice appear in all copies of the * software, derivative works or modified versions, and any portions * thereof, and that both notices appear in supporting documentation. * * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. * * Carnegie Mellon requests users of this software to return to * * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU * School of Computer Science * Carnegie Mellon University * Pittsburgh PA 15213-3890 * * any improvements or extensions that they make and grant Carnegie the * rights to redistribute these changes. */ #include #include #include #include #include #include #ifdef KTRACE #include #endif #include #include #ifdef DDB #include #endif #ifdef COMPAT_OSF1 #include #endif static __inline void userret __P((struct proc *, u_int64_t, u_quad_t)); void trap __P((const u_long, const u_long, const u_long, const u_long, struct trapframe *)); int unaligned_fixup __P((u_long, u_long, u_long, struct proc *)); void syscall __P((u_int64_t, struct trapframe *)); void child_return __P((struct proc *)); void ast __P((struct trapframe *)); u_long Sfloat_to_reg __P((u_int)); u_int reg_to_Sfloat __P((u_long)); u_long Tfloat_reg_cvt __P((u_long)); struct proc *fpcurproc; /* current user of the FPU */ void userret __P((struct proc *, u_int64_t, u_quad_t)); unsigned long Sfloat_to_reg __P((unsigned int)); unsigned int reg_to_Sfloat __P((unsigned long)); unsigned long Tfloat_reg_cvt __P((unsigned long)); #ifdef FIX_UNALIGNED_VAX_FP unsigned long Ffloat_to_reg __P((unsigned int)); unsigned int reg_to_Ffloat __P((unsigned long)); unsigned long Gfloat_reg_cvt __P((unsigned long)); #endif int unaligned_fixup __P((unsigned long, unsigned long, unsigned long, struct proc *)); /* * Define the code needed before returning to user mode, for * trap and syscall. */ void userret(p, pc, oticks) register struct proc *p; u_int64_t pc; u_quad_t oticks; { int sig, s; /* take pending signals */ while ((sig = CURSIG(p)) != 0) postsig(sig); p->p_priority = p->p_usrpri; if (want_resched) { /* * Since we are curproc, a clock interrupt could * change our priority without changing run queues * (the running process is not kept on a run queue). * If this happened after we setrunqueue ourselves but * before we switch()'ed, we might not be on the queue * indicated by our priority. */ s = splstatclock(); setrunqueue(p); p->p_stats->p_ru.ru_nivcsw++; mi_switch(); splx(s); while ((sig = CURSIG(p)) != 0) postsig(sig); } /* * If profiling, charge recent system time to the trapped pc. */ if (p->p_flag & P_PROFIL) { extern int psratio; addupc_task(p, pc, (int)(p->p_sticks - oticks) * psratio); } curpriority = p->p_priority; } char *trap_type[] = { "interrupt", /* 0 ALPHA_KENTRY_INT */ "arithmetic trap", /* 1 ALPHA_KENTRY_ARITH */ "memory management fault", /* 2 ALPHA_KENTRY_MM */ "instruction fault", /* 3 ALPHA_KENTRY_IF */ "unaligned access fault", /* 4 ALPHA_KENTRY_UNA */ "system call", /* 5 ALPHA_KENTRY_SYS */ }; int trap_types = sizeof trap_type / sizeof trap_type[0]; /* * Trap is called from locore to handle most types of processor traps. * System calls are broken out for efficiency and ASTs are broken out * to make the code a bit cleaner and more representative of the * Alpha architecture. */ /*ARGSUSED*/ void trap(a0, a1, a2, entry, framep) const unsigned long a0, a1, a2, entry; struct trapframe *framep; { register struct proc *p; register int i; u_long ucode; u_quad_t sticks; caddr_t v; int user; int typ; union sigval sv; cnt.v_trap++; p = curproc; v = 0; ucode = 0; user = (framep->tf_regs[FRAME_PS] & ALPHA_PSL_USERMODE) != 0; #ifdef DDB framep->tf_regs[FRAME_SP] = (long)framep + FRAME_SIZE*8; #endif if (user) { sticks = p->p_sticks; p->p_md.md_tf = framep; } else { #ifdef DIAGNOSTIC sticks = 0xdeadbeef; /* XXX for -Wuninitialized */ #endif } switch (entry) { case ALPHA_KENTRY_UNA: /* * If user-land, do whatever fixups, printing, and * signalling is appropriate (based on system-wide * and per-process unaligned-access-handling flags). */ if (user) { if ((i = unaligned_fixup(a0, a1, a2, p)) == 0) goto out; ucode = VM_PROT_NONE; /* XXX determine */ v = (caddr_t)a0; if (i == SIGBUS) typ = BUS_ADRALN; else typ = SEGV_MAPERR; break; } /* * Unaligned access from kernel mode is always an error, * EVEN IF A COPY FAULT HANDLER IS SET! * * It's an error if a copy fault handler is set because * the various routines which do user-initiated copies * do so in a bcopy-like manner. In other words, the * kernel never assumes that pointers provided by the * user are properly aligned, and so if the kernel * does cause an unaligned access it's a kernel bug. */ goto we_re_toast; case ALPHA_KENTRY_ARITH: /* * If user-land, just give a SIGFPE. Should do * software completion and IEEE handling, if the * user has requested that. */ if (user) { sigfpe: i = SIGFPE; v = NULL; /* XXX determine */ ucode = a0; /* exception summary */ typ = FPE_FLTINV; /* XXX? */ break; } /* Always fatal in kernel. Should never happen. */ goto we_re_toast; case ALPHA_KENTRY_IF: /* * These are always fatal in kernel, and should never * happen, unless they're breakpoints of course. */ if (!user) goto we_re_toast; switch (a0) { case ALPHA_IF_CODE_GENTRAP: if (framep->tf_regs[FRAME_A0] == -2) /* weird! */ goto sigfpe; case ALPHA_IF_CODE_BPT: case ALPHA_IF_CODE_BUGCHK: /* XXX what is the address? Guess on a1 for now */ v = (caddr_t)a1; ucode = 0; /* XXX determine */ i = SIGTRAP; typ = TRAP_BRKPT; break; case ALPHA_IF_CODE_OPDEC: /* XXX what is the address? Guess on a1 for now */ v = (caddr_t)a1; ucode = 0; /* XXX determine */ #ifdef NEW_PMAP { int instr; printf("REAL SIGILL: PC = 0x%lx, RA = 0x%lx\n", framep->tf_regs[FRAME_PC], framep->tf_regs[FRAME_RA]); printf("INSTRUCTION (%d) = 0x%lx\n", copyin((void*)framep->tf_regs[FRAME_PC] - 4, &instr, 4), instr); regdump(framep); panic("foo"); } #endif i = SIGILL; typ = ILL_ILLOPC; break; case ALPHA_IF_CODE_FEN: /* * on exit from the kernel, if proc == fpcurproc, * FP is enabled. */ if (fpcurproc == p) { printf("trap: fp disabled for fpcurproc == %p", p); goto we_re_toast; } alpha_pal_wrfen(1); if (fpcurproc) savefpstate(&fpcurproc->p_addr->u_pcb.pcb_fp); fpcurproc = p; restorefpstate(&fpcurproc->p_addr->u_pcb.pcb_fp); alpha_pal_wrfen(0); p->p_md.md_flags |= MDP_FPUSED; goto out; default: printf("trap: unknown IF type 0x%lx\n", a0); goto we_re_toast; } break; case ALPHA_KENTRY_MM: #ifdef NEW_PMAP printf("mmfault: 0x%lx, 0x%lx, %d\n", a0, a1, a2); #endif switch (a1) { case ALPHA_MMCSR_FOR: case ALPHA_MMCSR_FOE: #ifdef NEW_PMAP printf("mmfault for/foe in\n"); #endif pmap_emulate_reference(p, a0, user, 0); #ifdef NEW_PMAP printf("mmfault for/foe out\n"); #endif goto out; case ALPHA_MMCSR_FOW: #ifdef NEW_PMAP printf("mmfault fow in\n"); #endif pmap_emulate_reference(p, a0, user, 1); #ifdef NEW_PMAP printf("mmfault fow out\n"); #endif goto out; case ALPHA_MMCSR_INVALTRANS: case ALPHA_MMCSR_ACCESS: { register vm_offset_t va; register struct vmspace *vm; register vm_map_t map; vm_prot_t ftype; int rv; extern vm_map_t kernel_map; #ifdef NEW_PMAP printf("mmfault invaltrans/access in\n"); #endif /* * If it was caused by fuswintr or suswintr, * just punt. Note that we check the faulting * address against the address accessed by * [fs]uswintr, in case another fault happens * when they are running. */ if (!user && p != NULL && p->p_addr->u_pcb.pcb_onfault == (unsigned long)fswintrberr && p->p_addr->u_pcb.pcb_accessaddr == a0) { #ifdef NEW_PMAP printf("mmfault nfintr in\n"); #endif framep->tf_regs[FRAME_PC] = p->p_addr->u_pcb.pcb_onfault; p->p_addr->u_pcb.pcb_onfault = 0; #ifdef NEW_PMAP printf("mmfault nfintr out\n"); #endif goto out; } /* * It is only a kernel address space fault iff: * 1. !user and * 2. pcb_onfault not set or * 3. pcb_onfault set but kernel space data fault * The last can occur during an exec() copyin where the * argument space is lazy-allocated. */ if (!user && (a0 >= VM_MIN_KERNEL_ADDRESS || p == NULL || p->p_addr->u_pcb.pcb_onfault == 0)) map = kernel_map; else { vm = p->p_vmspace; map = &vm->vm_map; } switch (a2) { case -1: /* instruction fetch fault */ case 0: /* load instruction */ ftype = VM_PROT_READ; break; case 1: /* store instruction */ ftype = VM_PROT_WRITE; break; #ifdef DIAGNOSTIC default: /* XXX gcc -Wuninitialized */ goto we_re_toast; #endif } va = trunc_page((vm_offset_t)a0); #ifdef NEW_PMAP printf("mmfault going to vm_fault\n"); #endif rv = vm_fault(map, va, ftype, FALSE); #ifdef NEW_PMAP printf("mmfault back from vm_fault\n"); #endif /* * If this was a stack access we keep track of the * maximum accessed stack size. Also, if vm_fault * gets a protection failure it is due to accessing * the stack region outside the current limit and * we need to reflect that as an access error. */ if (map != kernel_map && (caddr_t)va >= vm->vm_maxsaddr) { if (rv == KERN_SUCCESS) { unsigned nss; nss = clrnd(btoc(USRSTACK - (unsigned long)va)); if (nss > vm->vm_ssize) vm->vm_ssize = nss; } else if (rv == KERN_PROTECTION_FAILURE) rv = KERN_INVALID_ADDRESS; } if (rv == KERN_SUCCESS) { #ifdef NEW_PMAP printf("mmfault vm_fault success\n"); #endif goto out; } if (!user) { #ifdef NEW_PMAP printf("mmfault check copyfault\n"); #endif /* Check for copyin/copyout fault */ if (p != NULL && p->p_addr->u_pcb.pcb_onfault != 0) { framep->tf_regs[FRAME_PC] = p->p_addr->u_pcb.pcb_onfault; p->p_addr->u_pcb.pcb_onfault = 0; goto out; } goto we_re_toast; } v = (caddr_t)a0; ucode = ftype; i = SIGSEGV; typ = SEGV_MAPERR; break; } default: printf("trap: unknown MMCSR value 0x%lx\n", a1); goto we_re_toast; } break; default: we_re_toast: #ifdef DDB if (kdb_trap(entry, a0, framep)) return; #endif goto dopanic; } sv.sival_ptr = v; trapsignal(p, i, ucode, typ, sv); out: if (user) userret(p, framep->tf_regs[FRAME_PC], sticks); return; dopanic: { const char *entryname = "???"; if (entry > 0 && entry < trap_types) entryname = trap_type[entry]; printf("\n"); printf("fatal %s trap:\n", user ? "user" : "kernel"); printf("\n"); printf(" trap entry = 0x%lx (%s)\n", entry, entryname); printf(" a0 = 0x%lx\n", a0); printf(" a1 = 0x%lx\n", a1); printf(" a2 = 0x%lx\n", a2); printf(" pc = 0x%lx\n", framep->tf_regs[FRAME_PC]); printf(" ra = 0x%lx\n", framep->tf_regs[FRAME_RA]); printf(" curproc = %p\n", curproc); if (curproc != NULL) printf(" pid = %d, comm = %s\n", curproc->p_pid, curproc->p_comm); printf("\n"); } /* XXX dump registers */ /* XXX kernel debugger */ panic("trap"); } /* * Process a system call. * * System calls are strange beasts. They are passed the syscall number * in v0, and the arguments in the registers (as normal). They return * an error flag in a3 (if a3 != 0 on return, the syscall had an error), * and the return value (if any) in v0. * * The assembly stub takes care of moving the call number into a register * we can get to, and moves all of the argument registers into their places * in the trap frame. On return, it restores the callee-saved registers, * a3, and v0 from the frame before returning to the user process. */ void syscall(code, framep) u_int64_t code; struct trapframe *framep; { struct sysent *callp; struct proc *p; int error, numsys; u_int64_t opc; u_quad_t sticks; u_int64_t rval[2]; u_int64_t args[10]; /* XXX */ u_int hidden, nargs; #ifdef COMPAT_OSF1 extern struct emul emul_osf1; #endif #if notdef /* can't happen, ever. */ if ((framep->tf_regs[FRAME_PS] & ALPHA_PSL_USERMODE) == 0) { panic("syscall"); #endif cnt.v_syscall++; p = curproc; p->p_md.md_tf = framep; opc = framep->tf_regs[FRAME_PC] - 4; sticks = p->p_sticks; callp = p->p_emul->e_sysent; numsys = p->p_emul->e_nsysent; #ifdef COMPAT_OSF1 if (p->p_emul == &emul_osf1) switch (code) { case OSF1_SYS_syscall: /* OSF/1 syscall() */ code = framep->tf_regs[FRAME_A0]; hidden = 1; break; default: hidden = 0; } else #endif switch(code) { case SYS_syscall: case SYS___syscall: /* * syscall() and __syscall() are handled the same on * the alpha, as everything is 64-bit aligned, anyway. */ code = framep->tf_regs[FRAME_A0]; hidden = 1; break; default: hidden = 0; } error = 0; if (code < numsys) callp += code; else callp += p->p_emul->e_nosys; nargs = callp->sy_narg + hidden; switch (nargs) { default: if (nargs > 10) /* XXX */ panic("syscall: too many args (%d)", nargs); error = copyin((caddr_t)(alpha_pal_rdusp()), &args[6], (nargs - 6) * sizeof(u_int64_t)); case 6: args[5] = framep->tf_regs[FRAME_A5]; case 5: args[4] = framep->tf_regs[FRAME_A4]; case 4: args[3] = framep->tf_regs[FRAME_A3]; case 3: args[2] = framep->tf_regs[FRAME_A2]; case 2: args[1] = framep->tf_regs[FRAME_A1]; case 1: args[0] = framep->tf_regs[FRAME_A0]; case 0: break; } #ifdef KTRACE if (KTRPOINT(p, KTR_SYSCALL)) ktrsyscall(p->p_tracep, code, callp->sy_argsize, args + hidden); #endif #ifdef SYSCALL_DEBUG scdebug_call(p, code, args + hidden); #ifdef NEW_PMAP printf("called from 0x%lx, ra 0x%lx\n", framep->tf_regs[FRAME_PC], framep->tf_regs[FRAME_RA]); #endif #endif if (error == 0) { rval[0] = 0; rval[1] = 0; error = (*callp->sy_call)(p, args + hidden, rval); } switch (error) { case 0: framep->tf_regs[FRAME_V0] = rval[0]; framep->tf_regs[FRAME_A4] = rval[1]; framep->tf_regs[FRAME_A3] = 0; break; case ERESTART: framep->tf_regs[FRAME_PC] = opc; break; case EJUSTRETURN: break; default: framep->tf_regs[FRAME_V0] = error; framep->tf_regs[FRAME_A3] = 1; break; } /* * Reinitialize proc pointer `p' as it may be different * if this is a child returning from fork syscall. */ p = curproc; #ifdef SYSCALL_DEBUG scdebug_ret(p, code, error, rval); #ifdef NEW_PMAP printf("outgoing pc 0x%lx, ra 0x%lx\n", framep->tf_regs[FRAME_PC], framep->tf_regs[FRAME_RA]); #endif #endif userret(p, framep->tf_regs[FRAME_PC], sticks); #ifdef KTRACE if (KTRPOINT(p, KTR_SYSRET)) ktrsysret(p->p_tracep, code, error, rval[0]); #endif } /* * Process the tail end of a fork() for the child. */ void child_return(p) struct proc *p; { /* * Return values in the frame set by cpu_fork(). */ userret(p, p->p_md.md_tf->tf_regs[FRAME_PC], 0); #ifdef KTRACE if (KTRPOINT(p, KTR_SYSRET)) ktrsysret(p->p_tracep, SYS_fork, 0, 0); #endif } /* * Process an asynchronous software trap. * This is relatively easy. */ void ast(framep) struct trapframe *framep; { register struct proc *p; u_quad_t sticks; p = curproc; sticks = p->p_sticks; p->p_md.md_tf = framep; if ((framep->tf_regs[FRAME_PS] & ALPHA_PSL_USERMODE) == 0) panic("ast and not user"); cnt.v_soft++; astpending = 0; if (p->p_flag & P_OWEUPC) { p->p_flag &= ~P_OWEUPC; ADDUPROF(p); } userret(p, framep->tf_regs[FRAME_PC], sticks); } /* * Unaligned access handler. It's not clear that this can get much slower... * */ const static int reg_to_framereg[32] = { FRAME_V0, FRAME_T0, FRAME_T1, FRAME_T2, FRAME_T3, FRAME_T4, FRAME_T5, FRAME_T6, FRAME_T7, FRAME_S0, FRAME_S1, FRAME_S2, FRAME_S3, FRAME_S4, FRAME_S5, FRAME_S6, FRAME_A0, FRAME_A1, FRAME_A2, FRAME_A3, FRAME_A4, FRAME_A5, FRAME_T8, FRAME_T9, FRAME_T10, FRAME_T11, FRAME_RA, FRAME_T12, FRAME_AT, FRAME_GP, FRAME_SP, -1, }; #define irp(p, reg) \ ((reg_to_framereg[(reg)] == -1) ? NULL : \ &(p)->p_md.md_tf->tf_regs[reg_to_framereg[(reg)]]) #define frp(p, reg) \ (&(p)->p_addr->u_pcb.pcb_fp.fpr_regs[(reg)]) #define dump_fp_regs() \ if (p == fpcurproc) { \ alpha_pal_wrfen(1); \ savefpstate(&fpcurproc->p_addr->u_pcb.pcb_fp); \ alpha_pal_wrfen(0); \ fpcurproc = NULL; \ } #define unaligned_load(storage, ptrf, mod) \ if (copyin((caddr_t)va, &(storage), sizeof (storage)) == 0 && \ (regptr = ptrf(p, reg)) != NULL) \ signal = 0; \ else \ break; \ *regptr = mod (storage); #define unaligned_store(storage, ptrf, mod) \ if ((regptr = ptrf(p, reg)) == NULL) \ break; \ (storage) = mod (*regptr); \ if (copyout(&(storage), (caddr_t)va, sizeof (storage)) == 0) \ signal = 0; \ else \ break; #define unaligned_load_integer(storage) \ unaligned_load(storage, irp, ) #define unaligned_store_integer(storage) \ unaligned_store(storage, irp, ) #define unaligned_load_floating(storage, mod) \ dump_fp_regs(); \ unaligned_load(storage, frp, mod) #define unaligned_store_floating(storage, mod) \ dump_fp_regs(); \ unaligned_store(storage, frp, mod) unsigned long Sfloat_to_reg(s) unsigned int s; { unsigned long sign, expn, frac; unsigned long result; sign = (s & 0x80000000) >> 31; expn = (s & 0x7f800000) >> 23; frac = (s & 0x007fffff) >> 0; /* map exponent part, as appropriate. */ if (expn == 0xff) expn = 0x7ff; else if ((expn & 0x80) != 0) expn = (0x400 | (expn & ~0x80)); else if ((expn & 0x80) == 0 && expn != 0) expn = (0x380 | (expn & ~0x80)); result = (sign << 63) | (expn << 52) | (frac << 29); return (result); } unsigned int reg_to_Sfloat(r) unsigned long r; { unsigned long sign, expn, frac; unsigned int result; sign = (r & 0x8000000000000000) >> 63; expn = (r & 0x7ff0000000000000) >> 52; frac = (r & 0x000fffffe0000000) >> 29; /* map exponent part, as appropriate. */ expn = (expn & 0x7f) | ((expn & 0x400) != 0 ? 0x80 : 0x00); result = (sign << 31) | (expn << 23) | (frac << 0); return (result); } /* * Conversion of T floating datums to and from register format * requires no bit reordering whatsoever. */ unsigned long Tfloat_reg_cvt(input) unsigned long input; { return (input); } #ifdef FIX_UNALIGNED_VAX_FP unsigned long Ffloat_to_reg(f) unsigned int f; { unsigned long sign, expn, frlo, frhi; unsigned long result; sign = (f & 0x00008000) >> 15; expn = (f & 0x00007f80) >> 7; frhi = (f & 0x0000007f) >> 0; frlo = (f & 0xffff0000) >> 16; /* map exponent part, as appropriate. */ if ((expn & 0x80) != 0) expn = (0x400 | (expn & ~0x80)); else if ((expn & 0x80) == 0 && expn != 0) expn = (0x380 | (expn & ~0x80)); result = (sign << 63) | (expn << 52) | (frhi << 45) | (frlo << 29); return (result); } unsigned int reg_to_Ffloat(r) unsigned long r; { unsigned long sign, expn, frhi, frlo; unsigned int result; sign = (r & 0x8000000000000000) >> 63; expn = (r & 0x7ff0000000000000) >> 52; frhi = (r & 0x000fe00000000000) >> 45; frlo = (r & 0x00001fffe0000000) >> 29; /* map exponent part, as appropriate. */ expn = (expn & 0x7f) | ((expn & 0x400) != 0 ? 0x80 : 0x00); result = (sign << 15) | (expn << 7) | (frhi << 0) | (frlo << 16); return (result); } /* * Conversion of G floating datums to and from register format is * symmetrical. Just swap shorts in the quad... */ unsigned long Gfloat_reg_cvt(input) unsigned long input; { unsigned long a, b, c, d; unsigned long result; a = (input & 0x000000000000ffff) >> 0; b = (input & 0x00000000ffff0000) >> 16; c = (input & 0x0000ffff00000000) >> 32; d = (input & 0xffff000000000000) >> 48; result = (a << 48) | (b << 32) | (c << 16) | (d << 0); return (result); } #endif /* FIX_UNALIGNED_VAX_FP */ extern int alpha_unaligned_print, alpha_unaligned_fix; extern int alpha_unaligned_sigbus; int unaligned_fixup(va, opcode, reg, p) unsigned long va, opcode, reg; struct proc *p; { int doprint, dofix, dosigbus; int signal, size; const char *type; unsigned long *regptr, longdata; int intdata; /* signed to get extension when storing */ struct { const char *type; /* opcode name */ int size; /* size, 0 if fixup not supported */ } tab[0x10] = { #ifdef FIX_UNALIGNED_VAX_FP { "ldf", 4 }, { "ldg", 8 }, #else { "ldf", 0 }, { "ldg", 0 }, #endif { "lds", 4 }, { "ldt", 8 }, #ifdef FIX_UNALIGNED_VAX_FP { "stf", 4 }, { "stg", 8 }, #else { "stf", 0 }, { "stg", 0 }, #endif { "sts", 4 }, { "stt", 8 }, { "ldl", 4 }, { "ldq", 8 }, { "ldl_l", 0 }, { "ldq_l", 0 }, /* can't fix */ { "stl", 4 }, { "stq", 8 }, { "stl_c", 0 }, { "stq_c", 0 }, /* can't fix */ }; int typ; /* * Figure out what actions to take. * * XXX In the future, this should have a per-process component * as well. */ doprint = alpha_unaligned_print; dofix = alpha_unaligned_fix; dosigbus = alpha_unaligned_sigbus; /* * Find out which opcode it is. Arrange to have the opcode * printed if it's an unknown opcode. */ if (opcode >= 0x20 && opcode <= 0x2f) { type = tab[opcode - 0x20].type; size = tab[opcode - 0x20].size; } else { type = "0x%lx"; size = 0; } /* * See if the user can access the memory in question. * Even if it's an unknown opcode, SEGV if the access * should have failed. */ if (!useracc((caddr_t)va, size ? size : 1, B_WRITE)) { signal = SIGSEGV; goto out; } /* * If we're supposed to be noisy, squawk now. */ if (doprint) { uprintf("pid %d (%s): unaligned access: va=0x%lx pc=0x%lx ra=0x%lx op=", p->p_pid, p->p_comm, va, p->p_md.md_tf->tf_regs[FRAME_PC], p->p_md.md_tf->tf_regs[FRAME_PC]); uprintf(type, opcode); uprintf("\n"); } /* * If we should try to fix it and know how, give it a shot. * * We never allow bad data to be unknowingly used by the * user process. That is, if we decide not to fix up an * access we cause a SIGBUS rather than letting the user * process go on without warning. * * If we're trying to do a fixup, we assume that things * will be botched. If everything works out OK, * unaligned_{load,store}_* clears the signal flag. */ signal = SIGBUS; typ = BUS_ADRALN; if (dofix && size != 0) { switch (opcode) { #ifdef FIX_UNALIGNED_VAX_FP case 0x20: /* ldf */ unaligned_load_floating(intdata, Ffloat_to_reg); break; case 0x21: /* ldg */ unaligned_load_floating(longdata, Gfloat_reg_cvt); break; #endif case 0x22: /* lds */ unaligned_load_floating(intdata, Sfloat_to_reg); break; case 0x23: /* ldt */ unaligned_load_floating(longdata, Tfloat_reg_cvt); break; #ifdef FIX_UNALIGNED_VAX_FP case 0x24: /* stf */ unaligned_store_floating(intdata, reg_to_Ffloat); break; case 0x25: /* stg */ unaligned_store_floating(longdata, Gfloat_reg_cvt); break; #endif case 0x26: /* sts */ unaligned_store_floating(intdata, reg_to_Sfloat); break; case 0x27: /* stt */ unaligned_store_floating(longdata, Tfloat_reg_cvt); break; case 0x28: /* ldl */ unaligned_load_integer(intdata); break; case 0x29: /* ldq */ unaligned_load_integer(longdata); break; case 0x2c: /* stl */ unaligned_store_integer(intdata); break; case 0x2d: /* stq */ unaligned_store_integer(longdata); break; #ifdef DIAGNOSTIC default: panic("unaligned_fixup: can't get here"); #endif } } /* * Force SIGBUS if requested. */ if (dosigbus) signal = SIGBUS; out: return (signal); }