/*- * Copyright (C) 1995, 1996 Wolfgang Solfrank. * Copyright (C) 1995, 1996 TooLs GmbH. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by TooLs GmbH. * 4. The name of TooLs GmbH may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * * $NetBSD: trap.c,v 1.58 2002/03/04 04:07:35 dbj Exp $ */ #include __FBSDID("$FreeBSD$"); #include "opt_hwpmc_hooks.h" #include "opt_kdtrace.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef HWPMC_HOOKS #include #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static void trap_fatal(struct trapframe *frame); static void printtrap(u_int vector, struct trapframe *frame, int isfatal, int user); static int trap_pfault(struct trapframe *frame, int user); static int fix_unaligned(struct thread *td, struct trapframe *frame); static int ppc_instr_emulate(struct trapframe *frame); static int handle_onfault(struct trapframe *frame); static void syscall(struct trapframe *frame); #ifdef __powerpc64__ void handle_kernel_slb_spill(int, register_t, register_t); static int handle_user_slb_spill(pmap_t pm, vm_offset_t addr); extern int n_slbs; #endif int setfault(faultbuf); /* defined in locore.S */ /* Why are these not defined in a header? */ int badaddr(void *, size_t); int badaddr_read(void *, size_t, int *); struct powerpc_exception { u_int vector; char *name; }; #ifdef KDTRACE_HOOKS #include /* * This is a hook which is initialised by the dtrace module * to handle traps which might occur during DTrace probe * execution. */ dtrace_trap_func_t dtrace_trap_func; dtrace_doubletrap_func_t dtrace_doubletrap_func; /* * This is a hook which is initialised by the systrace module * when it is loaded. This keeps the DTrace syscall provider * implementation opaque. */ systrace_probe_func_t systrace_probe_func; /* * These hooks are necessary for the pid, usdt and fasttrap providers. */ dtrace_fasttrap_probe_ptr_t dtrace_fasttrap_probe_ptr; dtrace_pid_probe_ptr_t dtrace_pid_probe_ptr; dtrace_return_probe_ptr_t dtrace_return_probe_ptr; int (*dtrace_invop_jump_addr)(struct trapframe *); #endif static struct powerpc_exception powerpc_exceptions[] = { { 0x0100, "system reset" }, { 0x0200, "machine check" }, { 0x0300, "data storage interrupt" }, { 0x0380, "data segment exception" }, { 0x0400, "instruction storage interrupt" }, { 0x0480, "instruction segment exception" }, { 0x0500, "external interrupt" }, { 0x0600, "alignment" }, { 0x0700, "program" }, { 0x0800, "floating-point unavailable" }, { 0x0900, "decrementer" }, { 0x0c00, "system call" }, { 0x0d00, "trace" }, { 0x0e00, "floating-point assist" }, { 0x0f00, "performance monitoring" }, { 0x0f20, "altivec unavailable" }, { 0x1000, "instruction tlb miss" }, { 0x1100, "data load tlb miss" }, { 0x1200, "data store tlb miss" }, { 0x1300, "instruction breakpoint" }, { 0x1400, "system management" }, { 0x1600, "altivec assist" }, { 0x1700, "thermal management" }, { 0x2000, "run mode/trace" }, { 0x3000, NULL } }; static const char * trapname(u_int vector) { struct powerpc_exception *pe; for (pe = powerpc_exceptions; pe->vector != 0x3000; pe++) { if (pe->vector == vector) return (pe->name); } return ("unknown"); } void trap(struct trapframe *frame) { struct thread *td; struct proc *p; int sig, type, user; u_int ucode; ksiginfo_t ksi; PCPU_INC(cnt.v_trap); td = curthread; p = td->td_proc; type = ucode = frame->exc; sig = 0; user = frame->srr1 & PSL_PR; CTR3(KTR_TRAP, "trap: %s type=%s (%s)", td->td_name, trapname(type), user ? "user" : "kernel"); #ifdef HWPMC_HOOKS if (type == EXC_PERF && (pmc_intr != NULL)) { (*pmc_intr)(PCPU_GET(cpuid), frame); if (user) userret(td, frame); return; } #endif #ifdef KDTRACE_HOOKS /* * A trap can occur while DTrace executes a probe. Before * executing the probe, DTrace blocks re-scheduling and sets * a flag in it's per-cpu flags to indicate that it doesn't * want to fault. On returning from the probe, the no-fault * flag is cleared and finally re-scheduling is enabled. * * If the DTrace kernel module has registered a trap handler, * call it and if it returns non-zero, assume that it has * handled the trap and modified the trap frame so that this * function can return normally. */ /* * XXXDTRACE: add fasttrap and pid probes handlers here (if ever) */ if (dtrace_trap_func != NULL && (*dtrace_trap_func)(frame, type)) return; #endif if (user) { td->td_pticks = 0; td->td_frame = frame; if (td->td_ucred != p->p_ucred) cred_update_thread(td); /* User Mode Traps */ switch (type) { case EXC_RUNMODETRC: case EXC_TRC: frame->srr1 &= ~PSL_SE; sig = SIGTRAP; break; #ifdef __powerpc64__ case EXC_ISE: case EXC_DSE: if (handle_user_slb_spill(&p->p_vmspace->vm_pmap, (type == EXC_ISE) ? frame->srr0 : frame->cpu.aim.dar) != 0) sig = SIGSEGV; break; #endif case EXC_DSI: case EXC_ISI: sig = trap_pfault(frame, 1); break; case EXC_SC: syscall(frame); break; case EXC_FPU: KASSERT((td->td_pcb->pcb_flags & PCB_FPU) != PCB_FPU, ("FPU already enabled for thread")); enable_fpu(td); break; case EXC_VEC: KASSERT((td->td_pcb->pcb_flags & PCB_VEC) != PCB_VEC, ("Altivec already enabled for thread")); enable_vec(td); break; case EXC_VECAST_G4: case EXC_VECAST_G5: /* * We get a VPU assist exception for IEEE mode * vector operations on denormalized floats. * Emulating this is a giant pain, so for now, * just switch off IEEE mode and treat them as * zero. */ save_vec(td); td->td_pcb->pcb_vec.vscr |= ALTIVEC_VSCR_NJ; enable_vec(td); break; case EXC_ALI: if (fix_unaligned(td, frame) != 0) sig = SIGBUS; else frame->srr0 += 4; break; case EXC_PGM: /* Identify the trap reason */ if (frame->srr1 & EXC_PGM_TRAP) sig = SIGTRAP; else if (ppc_instr_emulate(frame) == 0) frame->srr0 += 4; else sig = SIGILL; break; default: trap_fatal(frame); } } else { /* Kernel Mode Traps */ KASSERT(cold || td->td_ucred != NULL, ("kernel trap doesn't have ucred")); switch (type) { #ifdef KDTRACE_HOOKS case EXC_PGM: if (frame->srr1 & EXC_PGM_TRAP) { if (*(uintptr_t *)frame->srr0 == 0x7c810808) { if (dtrace_invop_jump_addr != NULL) { dtrace_invop_jump_addr(frame); return; } } } break; #endif #ifdef __powerpc64__ case EXC_DSE: if ((frame->cpu.aim.dar & SEGMENT_MASK) == USER_ADDR) { __asm __volatile ("slbmte %0, %1" :: "r"(td->td_pcb->pcb_cpu.aim.usr_vsid), "r"(USER_SLB_SLBE)); return; } break; #endif case EXC_DSI: if (trap_pfault(frame, 0) == 0) return; break; case EXC_MCHK: if (handle_onfault(frame)) return; break; default: break; } trap_fatal(frame); } if (sig != 0) { if (p->p_sysent->sv_transtrap != NULL) sig = (p->p_sysent->sv_transtrap)(sig, type); ksiginfo_init_trap(&ksi); ksi.ksi_signo = sig; ksi.ksi_code = (int) ucode; /* XXX, not POSIX */ /* ksi.ksi_addr = ? */ ksi.ksi_trapno = type; trapsignal(td, &ksi); } userret(td, frame); } static void trap_fatal(struct trapframe *frame) { printtrap(frame->exc, frame, 1, (frame->srr1 & PSL_PR)); #ifdef KDB if ((debugger_on_panic || kdb_active) && kdb_trap(frame->exc, 0, frame)) return; #endif panic("%s trap", trapname(frame->exc)); } static void printtrap(u_int vector, struct trapframe *frame, int isfatal, int user) { printf("\n"); printf("%s %s trap:\n", isfatal ? "fatal" : "handled", user ? "user" : "kernel"); printf("\n"); printf(" exception = 0x%x (%s)\n", vector, trapname(vector)); switch (vector) { case EXC_DSE: case EXC_DSI: printf(" virtual address = 0x%" PRIxPTR "\n", frame->cpu.aim.dar); printf(" dsisr = 0x%" PRIxPTR "\n", frame->cpu.aim.dsisr); break; case EXC_ISE: case EXC_ISI: printf(" virtual address = 0x%" PRIxPTR "\n", frame->srr0); break; } printf(" srr0 = 0x%" PRIxPTR "\n", frame->srr0); printf(" srr1 = 0x%" PRIxPTR "\n", frame->srr1); printf(" lr = 0x%" PRIxPTR "\n", frame->lr); printf(" curthread = %p\n", curthread); if (curthread != NULL) printf(" pid = %d, comm = %s\n", curthread->td_proc->p_pid, curthread->td_name); printf("\n"); } /* * Handles a fatal fault when we have onfault state to recover. Returns * non-zero if there was onfault recovery state available. */ static int handle_onfault(struct trapframe *frame) { struct thread *td; faultbuf *fb; td = curthread; fb = td->td_pcb->pcb_onfault; if (fb != NULL) { frame->srr0 = (*fb)[0]; frame->fixreg[1] = (*fb)[1]; frame->fixreg[2] = (*fb)[2]; frame->fixreg[3] = 1; frame->cr = (*fb)[3]; bcopy(&(*fb)[4], &frame->fixreg[13], 19 * sizeof(register_t)); return (1); } return (0); } int cpu_fetch_syscall_args(struct thread *td, struct syscall_args *sa) { struct proc *p; struct trapframe *frame; caddr_t params; size_t argsz; int error, n, i; p = td->td_proc; frame = td->td_frame; sa->code = frame->fixreg[0]; params = (caddr_t)(frame->fixreg + FIRSTARG); n = NARGREG; if (sa->code == SYS_syscall) { /* * code is first argument, * followed by actual args. */ sa->code = *(register_t *) params; params += sizeof(register_t); n -= 1; } else if (sa->code == SYS___syscall) { /* * Like syscall, but code is a quad, * so as to maintain quad alignment * for the rest of the args. */ if (SV_PROC_FLAG(p, SV_ILP32)) { params += sizeof(register_t); sa->code = *(register_t *) params; params += sizeof(register_t); n -= 2; } else { sa->code = *(register_t *) params; params += sizeof(register_t); n -= 1; } } if (p->p_sysent->sv_mask) sa->code &= p->p_sysent->sv_mask; if (sa->code >= p->p_sysent->sv_size) sa->callp = &p->p_sysent->sv_table[0]; else sa->callp = &p->p_sysent->sv_table[sa->code]; sa->narg = sa->callp->sy_narg; if (SV_PROC_FLAG(p, SV_ILP32)) { argsz = sizeof(uint32_t); for (i = 0; i < n; i++) sa->args[i] = ((u_register_t *)(params))[i] & 0xffffffff; } else { argsz = sizeof(uint64_t); for (i = 0; i < n; i++) sa->args[i] = ((u_register_t *)(params))[i]; } if (sa->narg > n) error = copyin(MOREARGS(frame->fixreg[1]), sa->args + n, (sa->narg - n) * argsz); else error = 0; #ifdef __powerpc64__ if (SV_PROC_FLAG(p, SV_ILP32) && sa->narg > n) { /* Expand the size of arguments copied from the stack */ for (i = sa->narg; i >= n; i--) sa->args[i] = ((uint32_t *)(&sa->args[n]))[i-n]; } #endif if (error == 0) { td->td_retval[0] = 0; td->td_retval[1] = frame->fixreg[FIRSTARG + 1]; } return (error); } #include "../../kern/subr_syscall.c" void syscall(struct trapframe *frame) { struct thread *td; struct syscall_args sa; int error; td = curthread; td->td_frame = frame; #ifdef __powerpc64__ /* * Speculatively restore last user SLB segment, which we know is * invalid already, since we are likely to do copyin()/copyout(). */ __asm __volatile ("slbmte %0, %1; isync" :: "r"(td->td_pcb->pcb_cpu.aim.usr_vsid), "r"(USER_SLB_SLBE)); #endif error = syscallenter(td, &sa); syscallret(td, error, &sa); } #ifdef __powerpc64__ /* Handle kernel SLB faults -- runs in real mode, all seat belts off */ void handle_kernel_slb_spill(int type, register_t dar, register_t srr0) { struct slb *slbcache; uint64_t slbe, slbv; uint64_t esid, addr; int i; addr = (type == EXC_ISE) ? srr0 : dar; slbcache = PCPU_GET(slb); esid = (uintptr_t)addr >> ADDR_SR_SHFT; slbe = (esid << SLBE_ESID_SHIFT) | SLBE_VALID; /* See if the hardware flushed this somehow (can happen in LPARs) */ for (i = 0; i < n_slbs; i++) if (slbcache[i].slbe == (slbe | (uint64_t)i)) return; /* Not in the map, needs to actually be added */ slbv = kernel_va_to_slbv(addr); if (slbcache[USER_SLB_SLOT].slbe == 0) { for (i = 0; i < n_slbs; i++) { if (i == USER_SLB_SLOT) continue; if (!(slbcache[i].slbe & SLBE_VALID)) goto fillkernslb; } if (i == n_slbs) slbcache[USER_SLB_SLOT].slbe = 1; } /* Sacrifice a random SLB entry that is not the user entry */ i = mftb() % n_slbs; if (i == USER_SLB_SLOT) i = (i+1) % n_slbs; fillkernslb: /* Write new entry */ slbcache[i].slbv = slbv; slbcache[i].slbe = slbe | (uint64_t)i; /* Trap handler will restore from cache on exit */ } static int handle_user_slb_spill(pmap_t pm, vm_offset_t addr) { struct slb *user_entry; uint64_t esid; int i; esid = (uintptr_t)addr >> ADDR_SR_SHFT; PMAP_LOCK(pm); user_entry = user_va_to_slb_entry(pm, addr); if (user_entry == NULL) { /* allocate_vsid auto-spills it */ (void)allocate_user_vsid(pm, esid, 0); } else { /* * Check that another CPU has not already mapped this. * XXX: Per-thread SLB caches would be better. */ for (i = 0; i < pm->pm_slb_len; i++) if (pm->pm_slb[i] == user_entry) break; if (i == pm->pm_slb_len) slb_insert_user(pm, user_entry); } PMAP_UNLOCK(pm); return (0); } #endif static int trap_pfault(struct trapframe *frame, int user) { vm_offset_t eva, va; struct thread *td; struct proc *p; vm_map_t map; vm_prot_t ftype; int rv; register_t user_sr; td = curthread; p = td->td_proc; if (frame->exc == EXC_ISI) { eva = frame->srr0; ftype = VM_PROT_EXECUTE; if (frame->srr1 & SRR1_ISI_PFAULT) ftype |= VM_PROT_READ; } else { eva = frame->cpu.aim.dar; if (frame->cpu.aim.dsisr & DSISR_STORE) ftype = VM_PROT_WRITE; else ftype = VM_PROT_READ; } if (user) { map = &p->p_vmspace->vm_map; } else { if ((eva >> ADDR_SR_SHFT) == (USER_ADDR >> ADDR_SR_SHFT)) { if (p->p_vmspace == NULL) return (SIGSEGV); map = &p->p_vmspace->vm_map; user_sr = td->td_pcb->pcb_cpu.aim.usr_segm; eva &= ADDR_PIDX | ADDR_POFF; eva |= user_sr << ADDR_SR_SHFT; } else { map = kernel_map; } } va = trunc_page(eva); if (map != kernel_map) { /* * Keep swapout from messing with us during this * critical time. */ PROC_LOCK(p); ++p->p_lock; PROC_UNLOCK(p); /* Fault in the user page: */ rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL); PROC_LOCK(p); --p->p_lock; PROC_UNLOCK(p); /* * XXXDTRACE: add dtrace_doubletrap_func here? */ } 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) return (0); if (!user && handle_onfault(frame)) return (0); return (SIGSEGV); } int badaddr(void *addr, size_t size) { return (badaddr_read(addr, size, NULL)); } int badaddr_read(void *addr, size_t size, int *rptr) { struct thread *td; faultbuf env; int x; /* Get rid of any stale machine checks that have been waiting. */ __asm __volatile ("sync; isync"); td = curthread; if (setfault(env)) { td->td_pcb->pcb_onfault = 0; __asm __volatile ("sync"); return 1; } __asm __volatile ("sync"); switch (size) { case 1: x = *(volatile int8_t *)addr; break; case 2: x = *(volatile int16_t *)addr; break; case 4: x = *(volatile int32_t *)addr; break; default: panic("badaddr: invalid size (%zd)", size); } /* Make sure we took the machine check, if we caused one. */ __asm __volatile ("sync; isync"); td->td_pcb->pcb_onfault = 0; __asm __volatile ("sync"); /* To be sure. */ /* Use the value to avoid reorder. */ if (rptr) *rptr = x; return (0); } /* * For now, this only deals with the particular unaligned access case * that gcc tends to generate. Eventually it should handle all of the * possibilities that can happen on a 32-bit PowerPC in big-endian mode. */ static int fix_unaligned(struct thread *td, struct trapframe *frame) { struct thread *fputhread; int indicator, reg; double *fpr; indicator = EXC_ALI_OPCODE_INDICATOR(frame->cpu.aim.dsisr); switch (indicator) { case EXC_ALI_LFD: case EXC_ALI_STFD: reg = EXC_ALI_RST(frame->cpu.aim.dsisr); fpr = &td->td_pcb->pcb_fpu.fpr[reg]; fputhread = PCPU_GET(fputhread); /* Juggle the FPU to ensure that we've initialized * the FPRs, and that their current state is in * the PCB. */ if (fputhread != td) { if (fputhread) save_fpu(fputhread); enable_fpu(td); } save_fpu(td); if (indicator == EXC_ALI_LFD) { if (copyin((void *)frame->cpu.aim.dar, fpr, sizeof(double)) != 0) return -1; enable_fpu(td); } else { if (copyout(fpr, (void *)frame->cpu.aim.dar, sizeof(double)) != 0) return -1; } return 0; break; } return -1; } static int ppc_instr_emulate(struct trapframe *frame) { uint32_t instr; int reg; instr = fuword32((void *)frame->srr0); if ((instr & 0xfc1fffff) == 0x7c1f42a6) { /* mfpvr */ reg = (instr & ~0xfc1fffff) >> 21; frame->fixreg[reg] = mfpvr(); return (0); } return (-1); }