/*ARGSUSED*/ void trap(struct frame *fp, int type, unsigned code, unsigned v) { extern char fubail[], subail[]; struct lwp *l; struct proc *p; struct pcb *pcb; void *onfault; ksiginfo_t ksi; int s; int rv; u_quad_t sticks = 0 /* XXX initialiser works around compiler bug */; static int panicking __diagused; curcpu()->ci_data.cpu_ntrap++; l = curlwp; p = l->l_proc; pcb = lwp_getpcb(l); KSI_INIT_TRAP(&ksi); ksi.ksi_trap = type & ~T_USER; if (USERMODE(fp->f_sr)) { type |= T_USER; sticks = p->p_sticks; l->l_md.md_regs = fp->f_regs; LWP_CACHE_CREDS(l, p); } switch (type) { default: dopanic: /* * Let the kernel debugger see the trap frame that * caused us to panic. This is a convenience so * one can see registers at the point of failure. */ s = splhigh(); panicking = 1; printf("trap type %d, code = 0x%x, v = 0x%x\n", type, code, v); printf("%s program counter = 0x%x\n", (type & T_USER) ? "user" : "kernel", fp->f_pc); #ifdef KGDB /* If connected, step or cont returns 1 */ if (kgdb_trap(type, (db_regs_t *)fp)) goto kgdb_cont; #endif #ifdef DDB (void)kdb_trap(type, (db_regs_t *)fp); #endif #ifdef KGDB kgdb_cont: #endif splx(s); if (panicstr) { printf("trap during panic!\n"); #ifdef DEBUG /* XXX should be a machine-dependent hook */ printf("(press a key)\n"); (void)cngetc(); #endif } regdump((struct trapframe *)fp, 128); type &= ~T_USER; if ((u_int)type < trap_types) panic(trap_type[type]); panic("trap"); case T_BUSERR: /* kernel bus error */ onfault = pcb->pcb_onfault; if (onfault == NULL) goto dopanic; rv = EFAULT; /* FALLTHROUGH */ copyfault: /* * If we have arranged to catch this fault in any of the * copy to/from user space routines, set PC to return to * indicated location and set flag informing buserror code * that it may need to clean up stack frame. */ fp->f_stackadj = exframesize[fp->f_format]; fp->f_format = fp->f_vector = 0; fp->f_pc = (int)onfault; fp->f_regs[D0] = rv; return; case T_BUSERR|T_USER: /* bus error */ case T_ADDRERR|T_USER: /* address error */ ksi.ksi_addr = (void *)v; ksi.ksi_signo = SIGBUS; ksi.ksi_code = (type == (T_BUSERR|T_USER)) ? BUS_OBJERR : BUS_ADRERR; break; case T_COPERR: /* kernel coprocessor violation */ case T_FMTERR|T_USER: /* do all RTE errors come in as T_USER? */ case T_FMTERR: /* ...just in case... */ /* * The user has most likely trashed the RTE or FP state info * in the stack frame of a signal handler. */ printf("pid %d: kernel %s exception\n", p->p_pid, type==T_COPERR ? "coprocessor" : "format"); type |= T_USER; mutex_enter(p->p_lock); SIGACTION(p, SIGILL).sa_handler = SIG_DFL; sigdelset(&p->p_sigctx.ps_sigignore, SIGILL); sigdelset(&p->p_sigctx.ps_sigcatch, SIGILL); sigdelset(&l->l_sigmask, SIGILL); mutex_exit(p->p_lock); ksi.ksi_signo = SIGILL; ksi.ksi_addr = (void *)(int)fp->f_format; /* XXX was ILL_RESAD_FAULT */ ksi.ksi_code = (type == T_COPERR) ? ILL_COPROC : ILL_ILLOPC; break; case T_COPERR|T_USER: /* user coprocessor violation */ /* What is a proper response here? */ ksi.ksi_signo = SIGFPE; ksi.ksi_code = FPE_FLTINV; break; case T_FPERR|T_USER: /* 68881 exceptions */ /* * We pass along the 68881 status register which locore stashed * in code for us. */ ksi.ksi_signo = SIGFPE; ksi.ksi_code = fpsr2siginfocode(code); break; #ifdef M68040 case T_FPEMULI|T_USER: /* unimplemented FP instruction */ case T_FPEMULD|T_USER: /* unimplemented FP data type */ /* XXX need to FSAVE */ printf("pid %d(%s): unimplemented FP %s at %x (EA %x)\n", p->p_pid, p->p_comm, fp->f_format == 2 ? "instruction" : "data type", fp->f_pc, fp->f_fmt2.f_iaddr); /* XXX need to FRESTORE */ ksi.ksi_signo = SIGFPE; ksi.ksi_code = FPE_FLTINV; break; #endif case T_ILLINST|T_USER: /* illegal instruction fault */ case T_PRIVINST|T_USER: /* privileged instruction fault */ ksi.ksi_addr = (void *)(int)fp->f_format; /* XXX was ILL_PRIVIN_FAULT */ ksi.ksi_signo = SIGILL; ksi.ksi_code = (type == (T_PRIVINST|T_USER)) ? ILL_PRVOPC : ILL_ILLOPC; break; case T_ZERODIV|T_USER: /* Divide by zero */ ksi.ksi_addr = (void *)(int)fp->f_format; /* XXX was FPE_INTDIV_TRAP */ ksi.ksi_signo = SIGFPE; ksi.ksi_code = FPE_FLTDIV; break; case T_CHKINST|T_USER: /* CHK instruction trap */ ksi.ksi_addr = (void *)(int)fp->f_format; /* XXX was FPE_SUBRNG_TRAP */ ksi.ksi_signo = SIGFPE; break; case T_TRAPVINST|T_USER: /* TRAPV instruction trap */ ksi.ksi_addr = (void *)(int)fp->f_format; /* XXX was FPE_INTOVF_TRAP */ ksi.ksi_signo = SIGFPE; break; /* * XXX: Trace traps are a nightmare. * * HP-UX uses trap #1 for breakpoints, * NetBSD/m68k uses trap #2, * SUN 3.x uses trap #15, * DDB and KGDB uses trap #15 (for kernel breakpoints; * handled elsewhere). * * NetBSD and HP-UX traps both get mapped by locore.s into T_TRACE. * SUN 3.x traps get passed through as T_TRAP15 and are not really * supported yet. * * XXX: We should never get kernel-mode T_TRAP15 * XXX: because locore.s now gives them special treatment. */ case T_TRAP15: /* kernel breakpoint */ #ifdef DEBUG printf("unexpected kernel trace trap, type = %d\n", type); printf("program counter = 0x%x\n", fp->f_pc); #endif fp->f_sr &= ~PSL_T; return; case T_TRACE|T_USER: /* user trace trap */ #ifdef COMPAT_SUNOS /* * SunOS uses Trap #2 for a "CPU cache flush". * Just flush the on-chip caches and return. */ if (p->p_emul == &emul_sunos) { ICIA(); DCIU(); return; } #endif /* FALLTHROUGH */ case T_TRACE: /* tracing a trap instruction */ case T_TRAP15|T_USER: /* SUN user trace trap */ fp->f_sr &= ~PSL_T; ksi.ksi_signo = SIGTRAP; break; case T_ASTFLT: /* system async trap, cannot happen */ goto dopanic; case T_ASTFLT|T_USER: /* user async trap */ astpending = 0; /* * We check for software interrupts first. This is because * they are at a higher level than ASTs, and on a VAX would * interrupt the AST. We assume that if we are processing * an AST that we must be at IPL0 so we don't bother to * check. Note that we ensure that we are at least at SIR * IPL while processing the SIR. */ spl1(); /* fall into... */ case T_SSIR: /* software interrupt */ case T_SSIR|T_USER: /* * If this was not an AST trap, we are all done. */ if (type != (T_ASTFLT|T_USER)) { curcpu()->ci_data.cpu_ntrap--; return; } spl0(); if (l->l_pflag & LP_OWEUPC) { l->l_pflag &= ~LP_OWEUPC; ADDUPROF(l); } if (curcpu()->ci_want_resched) preempt(); goto out; case T_MMUFLT: /* kernel mode page fault */ /* * If we were doing profiling ticks or other user mode * stuff from interrupt code, Just Say No. */ onfault = pcb->pcb_onfault; if (onfault == fubail || onfault == subail) { rv = EFAULT; goto copyfault; } /* fall into ... */ case T_MMUFLT|T_USER: /* page fault */ { vaddr_t va; struct vmspace *vm = p->p_vmspace; struct vm_map *map; vm_prot_t ftype; extern struct vm_map *kernel_map; onfault = pcb->pcb_onfault; #ifdef DEBUG if ((mmudebug & MDB_WBFOLLOW) || MDB_ISPID(p->p_pid)) printf("trap: T_MMUFLT pid=%d, code=%x, v=%x, pc=%x, sr=%x\n", p->p_pid, code, v, fp->f_pc, fp->f_sr); #endif /* * It is only a kernel address space fault iff: * 1. (type & T_USER) == 0 and * 2. pcb_onfault not set or * 3. pcb_onfault set but supervisor space data fault * The last can occur during an exec() copyin where the * argument space is lazy-allocated. */ if ((type & T_USER) == 0 && (onfault == NULL || KDFAULT(code))) map = kernel_map; else { map = vm ? &vm->vm_map : kernel_map; } if (WRFAULT(code)) ftype = VM_PROT_WRITE; else ftype = VM_PROT_READ; va = trunc_page((vaddr_t)v); if (map == kernel_map && va == 0) { printf("trap: bad kernel %s access at 0x%x\n", (ftype & VM_PROT_WRITE) ? "read/write" : "read", v); goto dopanic; } #ifdef DIAGNOSTIC if (interrupt_depth && !panicking) { printf("trap: calling uvm_fault() from interrupt!\n"); goto dopanic; } #endif pcb->pcb_onfault = NULL; rv = uvm_fault(map, va, ftype); pcb->pcb_onfault = onfault; #ifdef DEBUG if (rv && MDB_ISPID(p->p_pid)) printf("uvm_fault(%p, 0x%lx, 0x%x) -> 0x%x\n", map, va, ftype, rv); #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 (rv == 0) { if (map != kernel_map && (void *)va >= vm->vm_maxsaddr) uvm_grow(p, va); if (type == T_MMUFLT) { if (ucas_ras_check(&fp->F_t)) { return; } #ifdef M68040 if (cputype == CPU_68040) (void) writeback(fp, 1); #endif return; } goto out; } if (rv == EACCES) { ksi.ksi_code = SEGV_ACCERR; rv = EFAULT; } else ksi.ksi_code = SEGV_MAPERR; if (type == T_MMUFLT) { if (onfault) goto copyfault; printf("uvm_fault(%p, 0x%lx, 0x%x) -> 0x%x\n", map, va, ftype, rv); printf(" type %x, code [mmu,,ssw]: %x\n", type, code); goto dopanic; } ksi.ksi_addr = (void *)v; switch (rv) { case ENOMEM: printf("UVM: pid %d (%s), uid %d killed: out of swap\n", p->p_pid, p->p_comm, l->l_cred ? kauth_cred_geteuid(l->l_cred) : -1); ksi.ksi_signo = SIGKILL; break; case EINVAL: ksi.ksi_signo = SIGBUS; ksi.ksi_code = BUS_ADRERR; break; case EACCES: ksi.ksi_signo = SIGSEGV; ksi.ksi_code = SEGV_ACCERR; break; default: ksi.ksi_signo = SIGSEGV; ksi.ksi_code = SEGV_MAPERR; break; } break; } } trapsignal(l, &ksi); if ((type & T_USER) == 0) return; out: userret(l, fp, sticks, v, 1); }
/*ARGSUSED*/ void trap(struct trapframe *tf, int type, u_int code, u_int v) { struct lwp *l; struct proc *p; struct pcb *pcb; ksiginfo_t ksi; int tmp; int rv; u_quad_t sticks; void *onfault; curcpu()->ci_data.cpu_ntrap++; l = curlwp; p = l->l_proc; pcb = lwp_getpcb(l); onfault = pcb->pcb_onfault; KSI_INIT_TRAP(&ksi); ksi.ksi_trap = type & ~T_USER; KASSERT(pcb != NULL); if (USERMODE(tf->tf_sr)) { type |= T_USER; sticks = p->p_sticks; l->l_md.md_regs = tf->tf_regs; LWP_CACHE_CREDS(l, p); } else { sticks = 0; /* XXX: Detect trap recursion? */ } switch (type) { default: dopanic: printf("trap type=0x%x, code=0x%x, v=0x%x\n", type, code, v); /* * Let the kernel debugger see the trap frame that * caused us to panic. This is a convenience so * one can see registers at the point of failure. */ tmp = splhigh(); #ifdef KGDB /* If connected, step or cont returns 1 */ if (kgdb_trap(type, tf)) goto kgdb_cont; #endif #ifdef DDB (void) kdb_trap(type, (db_regs_t *) tf); #endif #ifdef KGDB kgdb_cont: #endif splx(tmp); if (panicstr) { /* * Note: panic is smart enough to do: * boot(RB_AUTOBOOT | RB_NOSYNC, NULL) * if we call it again. */ panic("trap during panic!"); } regdump(tf, 128); type &= ~T_USER; if ((u_int)type < trap_types) panic(trap_type[type]); panic("trap type 0x%x", type); case T_BUSERR: /* kernel bus error */ if (onfault == NULL) goto dopanic; rv = EFAULT; /*FALLTHROUGH*/ copyfault: /* * If we have arranged to catch this fault in any of the * copy to/from user space routines, set PC to return to * indicated location and set flag informing buserror code * that it may need to clean up stack frame. */ tf->tf_stackadj = exframesize[tf->tf_format]; tf->tf_format = tf->tf_vector = 0; tf->tf_pc = (int)onfault; tf->tf_regs[D0] = rv; goto done; case T_BUSERR|T_USER: /* bus error */ case T_ADDRERR|T_USER: /* address error */ ksi.ksi_addr = (void *)v; ksi.ksi_signo = SIGBUS; ksi.ksi_code = (type == (T_BUSERR|T_USER)) ? BUS_OBJERR : BUS_ADRERR; break; case T_COPERR: /* kernel coprocessor violation */ case T_FMTERR|T_USER: /* do all RTE errors come in as T_USER? */ case T_FMTERR: /* ...just in case... */ /* * The user has most likely trashed the RTE or FP state info * in the stack frame of a signal handler. */ printf("pid %d: kernel %s exception\n", p->p_pid, type==T_COPERR ? "coprocessor" : "format"); type |= T_USER; mutex_enter(p->p_lock); SIGACTION(p, SIGILL).sa_handler = SIG_DFL; sigdelset(&p->p_sigctx.ps_sigignore, SIGILL); sigdelset(&p->p_sigctx.ps_sigcatch, SIGILL); sigdelset(&l->l_sigmask, SIGILL); mutex_exit(p->p_lock); ksi.ksi_signo = SIGILL; ksi.ksi_addr = (void *)(int)tf->tf_format; ksi.ksi_code = (type == T_COPERR) ? ILL_COPROC : ILL_ILLOPC; break; case T_COPERR|T_USER: /* user coprocessor violation */ /* What is a proper response here? */ ksi.ksi_signo = SIGFPE; ksi.ksi_code = FPE_FLTINV; break; case T_FPERR|T_USER: /* 68881 exceptions */ /* * We pass along the 68881 status register which locore stashed * in code for us. */ ksi.ksi_signo = SIGFPE; ksi.ksi_code = fpsr2siginfocode(code); break; case T_FPEMULI: /* FPU faults in supervisor mode */ case T_FPEMULD: if (nofault) /* Doing FPU probe? */ longjmp(nofault); goto dopanic; case T_FPEMULI|T_USER: /* unimplemented FP instruction */ case T_FPEMULD|T_USER: /* unimplemented FP data type */ #ifdef FPU_EMULATE if (fpu_emulate(tf, &pcb->pcb_fpregs, &ksi) == 0) ; /* XXX - Deal with tracing? (tf->tf_sr & PSL_T) */ #else uprintf("pid %d killed: no floating point support\n", p->p_pid); ksi.ksi_signo = SIGILL; ksi.ksi_code = ILL_ILLOPC; #endif break; case T_ILLINST|T_USER: /* illegal instruction fault */ case T_PRIVINST|T_USER: /* privileged instruction fault */ ksi.ksi_addr = (void *)(int)tf->tf_format; ksi.ksi_signo = SIGILL; ksi.ksi_code = (type == (T_PRIVINST|T_USER)) ? ILL_PRVOPC : ILL_ILLOPC; break; case T_ZERODIV|T_USER: /* Divide by zero */ ksi.ksi_code = FPE_FLTDIV; case T_CHKINST|T_USER: /* CHK instruction trap */ case T_TRAPVINST|T_USER: /* TRAPV instruction trap */ ksi.ksi_addr = (void *)(int)tf->tf_format; ksi.ksi_signo = SIGFPE; break; /* * XXX: Trace traps are a nightmare. * * HP-UX uses trap #1 for breakpoints, * NetBSD/m68k uses trap #2, * SUN 3.x uses trap #15, * DDB and KGDB uses trap #15 (for kernel breakpoints; * handled elsewhere). * * NetBSD and HP-UX traps both get mapped by locore.s into T_TRACE. * SUN 3.x traps get passed through as T_TRAP15 and are not really * supported yet. * * XXX: We should never get kernel-mode T_TRAP15 * XXX: because locore.s now gives them special treatment. */ case T_TRAP15: /* kernel breakpoint */ tf->tf_sr &= ~PSL_T; goto done; case T_TRACE|T_USER: /* user trace trap */ #ifdef COMPAT_SUNOS /* * SunOS uses Trap #2 for a "CPU cache flush" * Just flush the on-chip caches and return. * XXX - Too bad NetBSD uses trap 2... */ if (p->p_emul == &emul_sunos) { /* get out fast */ goto done; } #endif /* FALLTHROUGH */ case T_TRACE: /* tracing a trap instruction */ case T_TRAP15|T_USER: /* SUN user trace trap */ tf->tf_sr &= ~PSL_T; ksi.ksi_signo = SIGTRAP; break; case T_ASTFLT: /* system async trap, cannot happen */ goto dopanic; case T_ASTFLT|T_USER: /* user async trap */ astpending = 0; /* T_SSIR is not used on a Sun2. */ if (l->l_pflag & LP_OWEUPC) { l->l_pflag &= ~LP_OWEUPC; ADDUPROF(l); } if (curcpu()->ci_want_resched) preempt(); goto douret; case T_MMUFLT: /* kernel mode page fault */ /* Hacks to avoid calling VM code from debugger. */ #ifdef DDB if (db_recover != 0) goto dopanic; #endif #ifdef KGDB if (kgdb_recover != 0) goto dopanic; #endif /* * If we were doing profiling ticks or other user mode * stuff from interrupt code, Just Say No. */ if (onfault == (void *)fubail || onfault == (void *)subail) { #ifdef DEBUG if (mmudebug & MDB_CPFAULT) { printf("trap: copyfault fu/su bail\n"); Debugger(); } #endif rv = EFAULT; goto copyfault; } /*FALLTHROUGH*/ case T_MMUFLT|T_USER: { /* page fault */ vaddr_t va; struct vmspace *vm = p->p_vmspace; struct vm_map *map; vm_prot_t ftype; extern struct vm_map *kernel_map; #ifdef DEBUG if ((mmudebug & MDB_WBFOLLOW) || MDB_ISPID(p->p_pid)) printf("trap: T_MMUFLT pid=%d, code=0x%x, v=0x%x, pc=0x%x, sr=0x%x\n", p->p_pid, code, v, tf->tf_pc, tf->tf_sr); #endif /* * It is only a kernel address space fault iff: * 1. (type & T_USER) == 0 and: (2 or 3) * 2. pcb_onfault not set or * 3. pcb_onfault set but supervisor space data fault * The last can occur during an exec() copyin where the * argument space is lazy-allocated. */ map = &vm->vm_map; if ((type & T_USER) == 0) { /* supervisor mode fault */ if (onfault == NULL || KDFAULT(code)) map = kernel_map; } if (WRFAULT(code)) ftype = VM_PROT_WRITE; else ftype = VM_PROT_READ; va = m68k_trunc_page((vaddr_t)v); /* * Need to resolve the fault. * * We give the pmap code a chance to resolve faults by * reloading translations that it was forced to unload. * This function does that, and calls vm_fault if it * could not resolve the fault by reloading the MMU. * This function may also, for example, disallow any * faults in the kernel text segment, etc. */ pcb->pcb_onfault = NULL; rv = _pmap_fault(map, va, ftype); pcb->pcb_onfault = onfault; #ifdef DEBUG if (rv && MDB_ISPID(p->p_pid)) { printf("vm_fault(%p, 0x%lx, 0x%x) -> 0x%x\n", map, va, ftype, rv); if (mmudebug & MDB_WBFAILED) Debugger(); } #endif /* DEBUG */ /* * 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 (rv == 0) { if (map != kernel_map && (void *)va >= vm->vm_maxsaddr) uvm_grow(p, va); if ((type & T_USER) == 0 && ucas_ras_check(tf)) { return; } goto finish; } if (rv == EACCES) { ksi.ksi_code = SEGV_ACCERR; rv = EFAULT; } else ksi.ksi_code = SEGV_MAPERR; if ((type & T_USER) == 0) { /* supervisor mode fault */ if (onfault) { #ifdef DEBUG if (mmudebug & MDB_CPFAULT) { printf("trap: copyfault pcb_onfault\n"); Debugger(); } #endif goto copyfault; } printf("vm_fault(%p, 0x%lx, 0x%x) -> 0x%x\n", map, va, ftype, rv); goto dopanic; } ksi.ksi_addr = (void *)v; switch (rv) { case ENOMEM: printf("UVM: pid %d (%s), uid %d killed: out of swap\n", p->p_pid, p->p_comm, l->l_cred ? kauth_cred_geteuid(l->l_cred) : -1); ksi.ksi_signo = SIGKILL; break; case EINVAL: ksi.ksi_signo = SIGBUS; ksi.ksi_code = BUS_ADRERR; break; case EACCES: ksi.ksi_signo = SIGSEGV; ksi.ksi_code = SEGV_ACCERR; break; default: ksi.ksi_signo = SIGSEGV; ksi.ksi_code = SEGV_MAPERR; break; } break; } /* T_MMUFLT */ } /* switch */ finish: /* If trap was from supervisor mode, just return. */ if ((type & T_USER) == 0) goto done; /* Post a signal if necessary. */ if (ksi.ksi_signo) trapsignal(l, &ksi); douret: userret(l, tf, sticks); done:; /* XXX: Detect trap recursion? */ }
void data_abort_handler(trapframe_t *tf) { struct vm_map *map; struct lwp * const l = curlwp; struct cpu_info * const ci = curcpu(); u_int far, fsr; vm_prot_t ftype; void *onfault; vaddr_t va; int error; ksiginfo_t ksi; UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); /* Grab FAR/FSR before enabling interrupts */ far = cpu_faultaddress(); fsr = cpu_faultstatus(); /* Update vmmeter statistics */ ci->ci_data.cpu_ntrap++; /* Re-enable interrupts if they were enabled previously */ KASSERT(!TRAP_USERMODE(tf) || (tf->tf_spsr & IF32_bits) == 0); if (__predict_true((tf->tf_spsr & IF32_bits) != IF32_bits)) restore_interrupts(tf->tf_spsr & IF32_bits); /* Get the current lwp structure */ UVMHIST_LOG(maphist, " (l=%#x, far=%#x, fsr=%#x", l, far, fsr, 0); UVMHIST_LOG(maphist, " tf=%#x, pc=%#x)", tf, tf->tf_pc, 0, 0); /* Data abort came from user mode? */ bool user = (TRAP_USERMODE(tf) != 0); if (user) LWP_CACHE_CREDS(l, l->l_proc); /* Grab the current pcb */ struct pcb * const pcb = lwp_getpcb(l); curcpu()->ci_abt_evs[fsr & FAULT_TYPE_MASK].ev_count++; /* Invoke the appropriate handler, if necessary */ if (__predict_false(data_aborts[fsr & FAULT_TYPE_MASK].func != NULL)) { #ifdef DIAGNOSTIC printf("%s: data_aborts fsr=0x%x far=0x%x\n", __func__, fsr, far); #endif if ((data_aborts[fsr & FAULT_TYPE_MASK].func)(tf, fsr, far, l, &ksi)) goto do_trapsignal; goto out; } /* * At this point, we're dealing with one of the following data aborts: * * FAULT_TRANS_S - Translation -- Section * FAULT_TRANS_P - Translation -- Page * FAULT_DOMAIN_S - Domain -- Section * FAULT_DOMAIN_P - Domain -- Page * FAULT_PERM_S - Permission -- Section * FAULT_PERM_P - Permission -- Page * * These are the main virtual memory-related faults signalled by * the MMU. */ /* fusubailout is used by [fs]uswintr to avoid page faulting */ if (__predict_false(pcb->pcb_onfault == fusubailout)) { tf->tf_r0 = EFAULT; tf->tf_pc = (intptr_t) pcb->pcb_onfault; return; } if (user) { lwp_settrapframe(l, tf); } /* * Make sure the Program Counter is sane. We could fall foul of * someone executing Thumb code, in which case the PC might not * be word-aligned. This would cause a kernel alignment fault * further down if we have to decode the current instruction. */ #ifdef THUMB_CODE /* * XXX: It would be nice to be able to support Thumb in the kernel * at some point. */ if (__predict_false(!user && (tf->tf_pc & 3) != 0)) { printf("\n%s: Misaligned Kernel-mode Program Counter\n", __func__); dab_fatal(tf, fsr, far, l, NULL); } #else if (__predict_false((tf->tf_pc & 3) != 0)) { if (user) { /* * Give the user an illegal instruction signal. */ /* Deliver a SIGILL to the process */ KSI_INIT_TRAP(&ksi); ksi.ksi_signo = SIGILL; ksi.ksi_code = ILL_ILLOPC; ksi.ksi_addr = (uint32_t *)(intptr_t) far; ksi.ksi_trap = fsr; goto do_trapsignal; } /* * The kernel never executes Thumb code. */ printf("\n%s: Misaligned Kernel-mode Program Counter\n", __func__); dab_fatal(tf, fsr, far, l, NULL); } #endif /* See if the CPU state needs to be fixed up */ switch (data_abort_fixup(tf, fsr, far, l)) { case ABORT_FIXUP_RETURN: return; case ABORT_FIXUP_FAILED: /* Deliver a SIGILL to the process */ KSI_INIT_TRAP(&ksi); ksi.ksi_signo = SIGILL; ksi.ksi_code = ILL_ILLOPC; ksi.ksi_addr = (uint32_t *)(intptr_t) far; ksi.ksi_trap = fsr; goto do_trapsignal; default: break; } va = trunc_page((vaddr_t)far); /* * It is only a kernel address space fault iff: * 1. user == 0 and * 2. pcb_onfault not set or * 3. pcb_onfault set and not LDRT/LDRBT/STRT/STRBT instruction. */ if (!user && (va >= VM_MIN_KERNEL_ADDRESS || (va < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW)) && __predict_true((pcb->pcb_onfault == NULL || (read_insn(tf->tf_pc, false) & 0x05200000) != 0x04200000))) { map = kernel_map; /* Was the fault due to the FPE/IPKDB ? */ if (__predict_false((tf->tf_spsr & PSR_MODE)==PSR_UND32_MODE)) { KSI_INIT_TRAP(&ksi); ksi.ksi_signo = SIGSEGV; ksi.ksi_code = SEGV_ACCERR; ksi.ksi_addr = (uint32_t *)(intptr_t) far; ksi.ksi_trap = fsr; /* * Force exit via userret() * This is necessary as the FPE is an extension to * userland that actually runs in a priveledged mode * but uses USR mode permissions for its accesses. */ user = true; goto do_trapsignal; } } else { map = &l->l_proc->p_vmspace->vm_map; } /* * We need to know whether the page should be mapped as R or R/W. * Before ARMv6, the MMU did not give us the info as to whether the * fault was caused by a read or a write. * * However, we know that a permission fault can only be the result of * a write to a read-only location, so we can deal with those quickly. * * Otherwise we need to disassemble the instruction responsible to * determine if it was a write. */ if (CPU_IS_ARMV6_P() || CPU_IS_ARMV7_P()) { ftype = (fsr & FAULT_WRITE) ? VM_PROT_WRITE : VM_PROT_READ; } else if (IS_PERMISSION_FAULT(fsr)) { ftype = VM_PROT_WRITE; } else { #ifdef THUMB_CODE /* Fast track the ARM case. */ if (__predict_false(tf->tf_spsr & PSR_T_bit)) { u_int insn = read_thumb_insn(tf->tf_pc, user); u_int insn_f8 = insn & 0xf800; u_int insn_fe = insn & 0xfe00; if (insn_f8 == 0x6000 || /* STR(1) */ insn_f8 == 0x7000 || /* STRB(1) */ insn_f8 == 0x8000 || /* STRH(1) */ insn_f8 == 0x9000 || /* STR(3) */ insn_f8 == 0xc000 || /* STM */ insn_fe == 0x5000 || /* STR(2) */ insn_fe == 0x5200 || /* STRH(2) */ insn_fe == 0x5400) /* STRB(2) */ ftype = VM_PROT_WRITE; else ftype = VM_PROT_READ; } else #endif { u_int insn = read_insn(tf->tf_pc, user); if (((insn & 0x0c100000) == 0x04000000) || /* STR[B] */ ((insn & 0x0e1000b0) == 0x000000b0) || /* STR[HD]*/ ((insn & 0x0a100000) == 0x08000000) || /* STM/CDT*/ ((insn & 0x0f9000f0) == 0x01800090)) /* STREX[BDH] */ ftype = VM_PROT_WRITE; else if ((insn & 0x0fb00ff0) == 0x01000090)/* SWP */ ftype = VM_PROT_READ | VM_PROT_WRITE; else ftype = VM_PROT_READ; } } /* * See if the fault is as a result of ref/mod emulation, * or domain mismatch. */ #ifdef DEBUG last_fault_code = fsr; #endif if (pmap_fault_fixup(map->pmap, va, ftype, user)) { UVMHIST_LOG(maphist, " <- ref/mod emul", 0, 0, 0, 0); goto out; } if (__predict_false(curcpu()->ci_intr_depth > 0)) { if (pcb->pcb_onfault) { tf->tf_r0 = EINVAL; tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; return; } printf("\nNon-emulated page fault with intr_depth > 0\n"); dab_fatal(tf, fsr, far, l, NULL); } onfault = pcb->pcb_onfault; pcb->pcb_onfault = NULL; error = uvm_fault(map, va, ftype); pcb->pcb_onfault = onfault; if (__predict_true(error == 0)) { if (user) uvm_grow(l->l_proc, va); /* Record any stack growth */ else ucas_ras_check(tf); UVMHIST_LOG(maphist, " <- uvm", 0, 0, 0, 0); goto out; } if (user == 0) { if (pcb->pcb_onfault) { tf->tf_r0 = error; tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; return; } printf("\nuvm_fault(%p, %lx, %x) -> %x\n", map, va, ftype, error); dab_fatal(tf, fsr, far, l, NULL); } KSI_INIT_TRAP(&ksi); if (error == ENOMEM) { printf("UVM: pid %d (%s), uid %d killed: " "out of swap\n", l->l_proc->p_pid, l->l_proc->p_comm, l->l_cred ? kauth_cred_geteuid(l->l_cred) : -1); ksi.ksi_signo = SIGKILL; } else ksi.ksi_signo = SIGSEGV; ksi.ksi_code = (error == EACCES) ? SEGV_ACCERR : SEGV_MAPERR; ksi.ksi_addr = (uint32_t *)(intptr_t) far; ksi.ksi_trap = fsr; UVMHIST_LOG(maphist, " <- error (%d)", error, 0, 0, 0); do_trapsignal: call_trapsignal(l, tf, &ksi); out: /* If returning to user mode, make sure to invoke userret() */ if (user) userret(l); }
/* * General page fault handler. */ void do_fault(struct trapframe *tf, struct lwp *l, struct vm_map *map, vaddr_t va, vm_prot_t atype) { int error; if (pmap_fault(map->pmap, va, atype)) return; struct pcb * const pcb = lwp_getpcb(l); void * const onfault = pcb->pcb_onfault; const bool user = TRAP_USERMODE(tf); if (cpu_intr_p()) { KASSERT(!user); error = EFAULT; } else { pcb->pcb_onfault = NULL; error = uvm_fault(map, va, atype); pcb->pcb_onfault = onfault; } if (error != 0) { ksiginfo_t ksi; if (onfault != NULL) { tf->tf_r0 = error; tf->tf_r15 = (tf->tf_r15 & ~R15_PC) | (register_t)onfault; return; } #ifdef DDB if (db_validating) { db_faulted = true; tf->tf_r15 += INSN_SIZE; return; } #endif if (!user) { #ifdef DDB db_printf("Unhandled data abort in kernel mode\n"); kdb_trap(T_FAULT, tf); #else #ifdef DEBUG printf("Unhandled data abort:\n"); printregs(tf); #endif panic("unhandled data abort in kernel mode"); #endif } KSI_INIT_TRAP(&ksi); if (error == ENOMEM) { printf("UVM: pid %d (%s), uid %d killed: " "out of swap\n", l->l_proc->p_pid, l->l_proc->p_comm, l->l_cred ? kauth_cred_geteuid(l->l_cred) : -1); ksi.ksi_signo = SIGKILL; } else ksi.ksi_signo = SIGSEGV; ksi.ksi_code = (error == EPERM) ? SEGV_ACCERR : SEGV_MAPERR; ksi.ksi_addr = (void *) va; trapsignal(l, &ksi); } else if (!user) { ucas_ras_check(tf); } }