/* $FreeBSD$ */ /* $NetBSD: trap.c,v 1.31 1998/03/26 02:21:46 thorpej 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 "opt_fix_unaligned_vax_fp.h" */ #include "opt_ddb.h" #include "opt_ktrace.h" #include "opt_simos.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef KTRACE #include #include #endif #ifdef DDB #include #endif #include /* for handle_opdec() */ unsigned long Sfloat_to_reg(unsigned int); unsigned int reg_to_Sfloat(unsigned long); unsigned long Tfloat_reg_cvt(unsigned long); #ifdef FIX_UNALIGNED_VAX_FP unsigned long Ffloat_to_reg(unsigned int); unsigned int reg_to_Ffloat(unsigned long); unsigned long Gfloat_reg_cvt(unsigned long); #endif int unaligned_fixup(unsigned long, unsigned long, unsigned long, struct thread *); int handle_opdec(struct thread *td, u_int64_t *ucodep); static void printtrap(const unsigned long, const unsigned long, const unsigned long, const unsigned long, struct trapframe *, int, int); #ifdef WITNESS extern char *syscallnames[]; #endif static const char *arith_exceptions[] = { "software completion", "invalid operation", "division by zero", "overflow", "underflow", "inexact result", "integer overflow", }; static const char *instruction_faults[] = { "bpt", "bugchk", "gentrap", "FEN", "opDec" }; static const char *interrupt_types[] = { "interprocessor", "clock", "correctable error", "machine check", "I/O device", "performance counter" }; static const char *mmfault_types[] = { "translation not valid", "access violation", "fault on read", "fault on execute", "fault on write" }; static const char *mmfault_causes[] = { "instruction fetch", "load instructon", "store instruction" }; static void printtrap(a0, a1, a2, entry, framep, isfatal, user) const unsigned long a0, a1, a2, entry; struct trapframe *framep; int isfatal, user; { char ubuf[64]; const char *entryname; unsigned long i; switch (entry) { case ALPHA_KENTRY_INT: entryname = "interrupt"; break; case ALPHA_KENTRY_ARITH: entryname = "arithmetic trap"; break; case ALPHA_KENTRY_MM: entryname = "memory management fault"; break; case ALPHA_KENTRY_IF: entryname = "instruction fault"; break; case ALPHA_KENTRY_UNA: entryname = "unaligned access fault"; break; case ALPHA_KENTRY_SYS: entryname = "system call"; break; default: snprintf(ubuf, sizeof(ubuf), "type %lx", entry); entryname = (const char *) ubuf; break; } printf("\n"); printf("%s %s trap:\n", isfatal? "fatal" : "handled", user ? "user" : "kernel"); printf("\n"); printf(" trap entry = 0x%lx (%s)\n", entry, entryname); #ifdef SMP printf(" cpuid = %d\n", PCPU_GET(cpuid)); #endif switch (entry) { case ALPHA_KENTRY_INT: printf(" interrupt type = "); if (a0 < 5) { printf("%s\n", interrupt_types[a0]); if (a0 > 1) { printf(" vector = 0x%lx\n", a1); if (a0 < 3) printf(" logout area = 0x%lx\n", a2); } } else printf("0x%lx (unknown)\n", a0); break; case ALPHA_KENTRY_ARITH: printf(" exception type = "); for (i = 0; i < 7; i++) if (a0 & (1 << i)) { printf("%s", arith_exceptions[i]); if (a0 & (~0 - (1 << i))) printf(", "); } printf("\n"); printf(" register mask = 0x%lx", a1); break; case ALPHA_KENTRY_MM: printf(" faulting va = 0x%lx\n", a0); printf(" type = "); if (a1 < 5) printf("%s\n", mmfault_types[a1]); else printf("0x%lx (unknown)\n", a1); printf(" cause = "); i = a2 + 1; if (i < 3) printf("%s\n", mmfault_causes[i]); else printf("0x%lx (unknown)\n", a2); break; case ALPHA_KENTRY_IF: printf(" fault type = "); if (a0 < 5) printf("%s\n", instruction_faults[a0]); else printf("0x%lx (unknown)\n", a0); break; case ALPHA_KENTRY_UNA: printf(" faulting va = 0x%lx\n", a0); printf(" opcode = 0x%lx\n", a1); printf(" register = 0x%lx\n", a2); break; default: printf(" a0 = 0x%lx\n", a0); printf(" a1 = 0x%lx\n", a1); printf(" a2 = 0x%lx\n", a2); break; } printf(" pc = 0x%lx\n", framep->tf_regs[FRAME_PC]); printf(" ra = 0x%lx\n", framep->tf_regs[FRAME_RA]); printf(" sp = 0x%lx\n", framep->tf_regs[FRAME_SP]); if (curthread != NULL && (curthread->td_proc->p_flag & P_KTHREAD) == 0) printf(" usp = 0x%lx\n", alpha_pal_rdusp()); printf(" curthread = %p\n", curthread); if (curthread != NULL) printf(" pid = %d, comm = %s\n", curthread->td_proc->p_pid, curthread->td_proc->p_comm); printf("\n"); } /* * 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 thread *td; register struct proc *p; register int i; u_int64_t ucode; u_int sticks; int user; #ifdef SMP register_t s; #endif /* * Find our per-cpu globals. */ #ifdef SMP s = intr_disable(); #endif pcpup = (struct pcpu *) alpha_pal_rdval(); td = curthread; #ifdef SMP if (td == NULL) { printtrap(a0, a1, a2, entry, framep, 1, 0); cpu_halt(); } td->td_md.md_kernnest++; intr_restore(s); #endif p = td->td_proc; /* GIANT_REQUIRED; * Giant hasn't been acquired yet. */ cnt.v_trap++; ucode = 0; user = (framep->tf_regs[FRAME_PS] & ALPHA_PSL_USERMODE) != 0; CTR5(KTR_TRAP, "%s trap: pid %d, (%lx, %lx, %lx)", user ? "user" : "kernel", p->p_pid, a0, a1, a2); if (user) { sticks = td->td_kse->ke_sticks; td->td_frame = framep; if (td->td_ucred != p->p_ucred) cred_update_thread(td); } else { sticks = 0; /* XXX bogus -Wuninitialized warning */ KASSERT(cold || td->td_ucred != NULL, ("kernel trap doesn't have ucred")); } #ifdef DIAGNOSTIC if (user) alpha_fpstate_check(td); #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) { mtx_lock(&Giant); i = unaligned_fixup(a0, a1, a2, td); mtx_unlock(&Giant); if (i == 0) goto out; ucode = a0; /* VA */ 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 dopanic; case ALPHA_KENTRY_ARITH: /* * If user-land, give a SIGFPE if software completion * is not requested or if the completion fails. */ if (user) { mtx_lock(&Giant); if (a0 & EXCSUM_SWC) if (fp_software_completion(a1, td)) { mtx_unlock(&Giant); goto out; } mtx_unlock(&Giant); i = SIGFPE; ucode = a0; /* exception summary */ break; } /* Always fatal in kernel. Should never happen. */ goto dopanic; case ALPHA_KENTRY_IF: /* * These are always fatal in kernel, and should never happen. */ if (!user) { #ifdef DDB /* * ...unless, of course, DDB is configured; BUGCHK * is used to invoke the kernel debugger, and we * might have set a breakpoint. */ if (a0 == ALPHA_IF_CODE_BUGCHK || a0 == ALPHA_IF_CODE_BPT #ifdef SIMOS || a0 == ALPHA_IF_CODE_GENTRAP #endif ) { if (kdb_trap(a0, a1, a2, entry, framep)) goto out; } /* * If we get here, DDB did _not_ handle the * trap, and we need to PANIC! */ #endif goto dopanic; } i = 0; switch (a0) { case ALPHA_IF_CODE_GENTRAP: if (framep->tf_regs[FRAME_A0] == -2) { /* weird! */ i = SIGFPE; ucode = a0; /* exception summary */ break; } /* FALLTHROUTH */ case ALPHA_IF_CODE_BPT: case ALPHA_IF_CODE_BUGCHK: if (td->td_md.md_flags & (MDP_STEP1|MDP_STEP2)) { mtx_lock(&Giant); ptrace_clear_single_step(td); td->td_frame->tf_regs[FRAME_PC] -= 4; mtx_unlock(&Giant); } ucode = a0; /* trap type */ i = SIGTRAP; break; case ALPHA_IF_CODE_OPDEC: i = handle_opdec(td, &ucode); if (i == 0) goto out; break; case ALPHA_IF_CODE_FEN: /* * on exit from the kernel, if thread == fpcurthread, * FP is enabled. */ if (PCPU_GET(fpcurthread) == td) { printf("trap: fp disabled for fpcurthread == %p", td); goto dopanic; } alpha_fpstate_switch(td); goto out; default: printf("trap: unknown IF type 0x%lx\n", a0); goto dopanic; } break; case ALPHA_KENTRY_MM: switch (a1) { case ALPHA_MMCSR_FOR: case ALPHA_MMCSR_FOE: case ALPHA_MMCSR_FOW: pmap_emulate_reference(p->p_vmspace, a0, user, a1 == ALPHA_MMCSR_FOW); goto out; case ALPHA_MMCSR_INVALTRANS: case ALPHA_MMCSR_ACCESS: { register vm_offset_t va; register struct vmspace *vm = NULL; register vm_map_t map; vm_prot_t ftype = 0; int rv; /* * 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 && td != NULL && td->td_pcb->pcb_onfault == (unsigned long)fswintrberr && td->td_pcb->pcb_accessaddr == a0) { framep->tf_regs[FRAME_PC] = td->td_pcb->pcb_onfault; td->td_pcb->pcb_onfault = 0; 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. * * For the purposes of the Linux emulator, we allow * kernel accesses to a small region of the * user stack which the emulator uses to * translate syscall arguments. */ if (!user && ((a0 >= VM_MIN_KERNEL_ADDRESS) || (td == NULL) || (td->td_pcb->pcb_onfault == 0))) { if (a0 >= trunc_page(PS_STRINGS - szsigcode - SPARE_USRSPACE) && a0 < round_page(PS_STRINGS - szsigcode)) { vm = p->p_vmspace; map = &vm->vm_map; } else { 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 dopanic; #endif } va = trunc_page((vm_offset_t)a0); if (map != kernel_map) { /* * Keep swapout from messing with us * during thiscritical time. */ PROC_LOCK(p); ++p->p_lock; PROC_UNLOCK(p); /* Fault in the user page: */ rv = vm_fault(map, va, ftype, (ftype & VM_PROT_WRITE) ? VM_FAULT_DIRTY : VM_FAULT_NORMAL); PROC_LOCK(p); --p->p_lock; PROC_UNLOCK(p); } else { /* * Don't have to worry about process * locking or stacks in the kernel. */ rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL); } if (rv == KERN_SUCCESS) goto out; if (!user) { /* Check for copyin/copyout fault */ if (td != NULL && td->td_pcb->pcb_onfault != 0) { framep->tf_regs[FRAME_PC] = td->td_pcb->pcb_onfault; td->td_pcb->pcb_onfault = 0; goto out; } goto dopanic; } ucode = a0; i = SIGSEGV; #ifdef DEBUG printtrap(a0, a1, a2, entry, framep, 1, user); #endif break; } default: printf("trap: unknown MMCSR value 0x%lx\n", a1); goto dopanic; } break; default: goto dopanic; } #ifdef DEBUG printtrap(a0, a1, a2, entry, framep, 1, user); #endif framep->tf_regs[FRAME_TRAPARG_A0] = a0; framep->tf_regs[FRAME_TRAPARG_A1] = a1; framep->tf_regs[FRAME_TRAPARG_A2] = a2; trapsignal(p, i, ucode); out: if (user) { framep->tf_regs[FRAME_SP] = alpha_pal_rdusp(); userret(td, framep, sticks); mtx_assert(&Giant, MA_NOTOWNED); #ifdef DIAGNOSTIC cred_free_thread(td); #endif } return; dopanic: printtrap(a0, a1, a2, entry, framep, 1, user); /* XXX dump registers */ #ifdef DDB kdb_trap(a0, a1, a2, entry, framep); #endif 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 thread *td; struct proc *p; int error = 0; u_int64_t opc; u_int sticks; u_int64_t args[10]; /* XXX */ u_int hidden = 0, nargs; #ifdef SMP register_t s; #endif /* * Find our per-cpu globals. */ #ifdef SMP s = intr_disable(); #endif pcpup = (struct pcpu *) alpha_pal_rdval(); td = curthread; #ifdef SMP td->td_md.md_kernnest++; intr_restore(s); #endif p = td->td_proc; framep->tf_regs[FRAME_TRAPARG_A0] = 0; framep->tf_regs[FRAME_TRAPARG_A1] = 0; framep->tf_regs[FRAME_TRAPARG_A2] = 0; #if notdef /* can't happen, ever. */ if ((framep->tf_regs[FRAME_PS] & ALPHA_PSL_USERMODE) == 0) panic("syscall"); #endif cnt.v_syscall++; td->td_frame = framep; opc = framep->tf_regs[FRAME_PC] - 4; sticks = td->td_kse->ke_sticks; if (td->td_ucred != p->p_ucred) cred_update_thread(td); #ifdef DIAGNOSTIC alpha_fpstate_check(td); #endif if (p->p_sysent->sv_prepsyscall) { /* (*p->p_sysent->sv_prepsyscall)(framep, args, &code, ¶ms); */ panic("prepsyscall"); } else { /* * syscall() and __syscall() are handled the same on * the alpha, as everything is 64-bit aligned, anyway. */ if (code == SYS_syscall || code == SYS___syscall) { /* * Code is first argument, followed by actual args. */ code = framep->tf_regs[FRAME_A0]; hidden = 1; } } if (p->p_sysent->sv_mask) code &= p->p_sysent->sv_mask; if (code >= p->p_sysent->sv_size) callp = &p->p_sysent->sv_table[0]; else callp = &p->p_sysent->sv_table[code]; nargs = (callp->sy_narg & SYF_ARGMASK) + 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(td, KTR_SYSCALL)) ktrsyscall(code, (callp->sy_narg & SYF_ARGMASK), args + hidden); #endif /* * Try to run the syscall without the MP lock if the syscall * is MP safe */ if ((callp->sy_narg & SYF_MPSAFE) == 0) mtx_lock(&Giant); if (error == 0) { td->td_retval[0] = 0; td->td_retval[1] = 0; STOPEVENT(p, S_SCE, (callp->sy_narg & SYF_ARGMASK)); error = (*callp->sy_call)(td, args + hidden); } switch (error) { case 0: framep->tf_regs[FRAME_V0] = td->td_retval[0]; framep->tf_regs[FRAME_A4] = td->td_retval[1]; framep->tf_regs[FRAME_A3] = 0; break; case ERESTART: framep->tf_regs[FRAME_PC] = opc; break; case EJUSTRETURN: break; default: if (p->p_sysent->sv_errsize) { if (error >= p->p_sysent->sv_errsize) error = -1; /* XXX */ else error = p->p_sysent->sv_errtbl[error]; } framep->tf_regs[FRAME_V0] = error; framep->tf_regs[FRAME_A3] = 1; break; } userret(td, framep, sticks); /* * Release Giant if we had to get it. */ if ((callp->sy_narg & SYF_MPSAFE) == 0) mtx_unlock(&Giant); #ifdef KTRACE if (KTRPOINT(td, KTR_SYSRET)) ktrsysret(code, error, td->td_retval[0]); #endif /* * This works because errno is findable through the * register set. If we ever support an emulation where this * is not the case, this code will need to be revisited. */ STOPEVENT(p, S_SCX, code); #ifdef DIAGNOSTIC cred_free_thread(td); #endif #ifdef WITNESS if (witness_list(td)) { panic("system call %s returning with mutex(s) held\n", syscallnames[code]); } #endif mtx_assert(&sched_lock, MA_NOTOWNED); mtx_assert(&Giant, MA_NOTOWNED); } /* * 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(td, reg) \ ((reg_to_framereg[(reg)] == -1) ? NULL : \ &(td)->td_frame->tf_regs[reg_to_framereg[(reg)]]) #define frp(td, reg) \ (&(td)->td_pcb->pcb_fp.fpr_regs[(reg)]) #define unaligned_load(storage, ptrf, mod) \ if (copyin((caddr_t)va, &(storage), sizeof (storage)) == 0 && \ (regptr = ptrf(td, reg)) != NULL) \ signal = 0; \ else \ break; \ *regptr = mod (storage); #define unaligned_store(storage, ptrf, mod) \ if ((regptr = ptrf(td, reg)) == NULL) \ (storage) = 0; \ else \ (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) \ alpha_fpstate_save(td, 1); \ unaligned_load(storage, frp, mod) #define unaligned_store_floating(storage, mod) \ alpha_fpstate_save(td, 0); \ 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; struct unaligned_fixup_data { const char *type; /* opcode name */ int size; /* size, 0 if fixup not supported */ }; int unaligned_fixup(va, opcode, reg, td) unsigned long va, opcode, reg; struct thread *td; { int doprint, dofix, dosigbus; int signal, size; const char *type; struct proc *p; unsigned long *regptr, longdata, uac; int intdata; /* signed to get extension when storing */ u_int16_t worddata; /* unsigned to _avoid_ extension */ const struct unaligned_fixup_data tab_0c[0x2] = { { "ldwu", 2 }, { "stw", 2 }, }; const struct unaligned_fixup_data tab_20[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 */ }; /* * Figure out what actions to take. * */ if (td) { uac = td->td_md.md_flags & MDP_UAC_MASK; p = td->td_proc; } else { uac = 0; p = NULL; } doprint = alpha_unaligned_print && !(uac & MDP_UAC_NOPRINT); dofix = alpha_unaligned_fix && !(uac & MDP_UAC_NOFIX); dosigbus = alpha_unaligned_sigbus | (uac & MDP_UAC_SIGBUS); /* * Find out which opcode it is. Arrange to have the opcode * printed if it's an unknown opcode. */ if (opcode >= 0x0c && opcode <= 0x0d) { type = tab_0c[opcode - 0x0c].type; size = tab_0c[opcode - 0x0c].size; } else if (opcode >= 0x20 && opcode <= 0x2f) { type = tab_20[opcode - 0x20].type; size = tab_20[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, VM_PROT_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, td->td_frame->tf_regs[FRAME_PC], td->td_frame->tf_regs[FRAME_RA]); 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; if (dofix && size != 0) { switch (opcode) { case 0x0c: /* ldwu */ /* XXX ONLY WORKS ON LITTLE-ENDIAN ALPHA */ unaligned_load_integer(worddata); break; case 0x0d: /* stw */ /* XXX ONLY WORKS ON LITTLE-ENDIAN ALPHA */ unaligned_store_integer(worddata); break; #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); } /* * Reserved/unimplemented instruction (opDec fault) handler * * Argument is the process that caused it. No useful information * is passed to the trap handler other than the fault type. The * address of the instruction that caused the fault is 4 less than * the PC stored in the trap frame. * * If the instruction is emulated successfully, this function returns 0. * Otherwise, this function returns the signal to deliver to the process, * and fills in *ucodep with the code to be delivered. */ int handle_opdec(td, ucodep) struct thread *td; u_int64_t *ucodep; { alpha_instruction inst; register_t *regptr, memaddr; u_int64_t inst_pc; int sig; /* * Read USP into frame in case it's going to be used or modified. * This keeps us from having to check for it in lots of places * later. */ td->td_frame->tf_regs[FRAME_SP] = alpha_pal_rdusp(); inst_pc = memaddr = td->td_frame->tf_regs[FRAME_PC] - 4; if (copyin((caddr_t)inst_pc, &inst, sizeof (inst)) != 0) { /* * really, this should never happen, but in case it * does we handle it. */ printf("WARNING: handle_opdec() couldn't fetch instruction\n"); goto sigsegv; } switch (inst.generic_format.opcode) { case op_ldbu: case op_ldwu: case op_stw: case op_stb: regptr = irp(td, inst.mem_format.rs); if (regptr != NULL) memaddr = *regptr; else memaddr = 0; memaddr += inst.mem_format.displacement; regptr = irp(td, inst.mem_format.rd); if (inst.mem_format.opcode == op_ldwu || inst.mem_format.opcode == op_stw) { if (memaddr & 0x01) { sig = unaligned_fixup(memaddr, inst.mem_format.opcode, inst.mem_format.rd, td); if (sig) goto unaligned_fixup_sig; break; } } if (inst.mem_format.opcode == op_ldbu) { u_int8_t b; /* XXX ONLY WORKS ON LITTLE-ENDIAN ALPHA */ if (copyin((caddr_t)memaddr, &b, sizeof (b)) != 0) goto sigsegv; if (regptr != NULL) *regptr = b; } else if (inst.mem_format.opcode == op_ldwu) { u_int16_t w; /* XXX ONLY WORKS ON LITTLE-ENDIAN ALPHA */ if (copyin((caddr_t)memaddr, &w, sizeof (w)) != 0) goto sigsegv; if (regptr != NULL) *regptr = w; } else if (inst.mem_format.opcode == op_stw) { u_int16_t w; /* XXX ONLY WORKS ON LITTLE-ENDIAN ALPHA */ w = (regptr != NULL) ? *regptr : 0; if (copyout(&w, (caddr_t)memaddr, sizeof (w)) != 0) goto sigsegv; } else if (inst.mem_format.opcode == op_stb) { u_int8_t b; /* XXX ONLY WORKS ON LITTLE-ENDIAN ALPHA */ b = (regptr != NULL) ? *regptr : 0; if (copyout(&b, (caddr_t)memaddr, sizeof (b)) != 0) goto sigsegv; } break; case op_intmisc: if (inst.operate_generic_format.function == op_sextb && inst.operate_generic_format.ra == 31) { int8_t b; if (inst.operate_generic_format.is_lit) { b = inst.operate_lit_format.literal; } else { if (inst.operate_reg_format.sbz != 0) goto sigill; regptr = irp(td, inst.operate_reg_format.rt); b = (regptr != NULL) ? *regptr : 0; } regptr = irp(td, inst.operate_generic_format.rc); if (regptr != NULL) *regptr = b; break; } if (inst.operate_generic_format.function == op_sextw && inst.operate_generic_format.ra == 31) { int16_t w; if (inst.operate_generic_format.is_lit) { w = inst.operate_lit_format.literal; } else { if (inst.operate_reg_format.sbz != 0) goto sigill; regptr = irp(td, inst.operate_reg_format.rt); w = (regptr != NULL) ? *regptr : 0; } regptr = irp(td, inst.operate_generic_format.rc); if (regptr != NULL) *regptr = w; break; } goto sigill; default: goto sigill; } /* * Write back USP. Note that in the error cases below, * nothing will have been successfully modified so we don't * have to write it out. */ alpha_pal_wrusp(td->td_frame->tf_regs[FRAME_SP]); return (0); sigill: *ucodep = ALPHA_IF_CODE_OPDEC; /* trap type */ return (SIGILL); sigsegv: sig = SIGSEGV; td->td_frame->tf_regs[FRAME_PC] = inst_pc; /* re-run instr. */ unaligned_fixup_sig: *ucodep = memaddr; /* faulting address */ return (sig); }