static __inline int prefetch_abort_fixup(trapframe_t *tf, struct ksig *ksig) { #ifdef CPU_ABORT_FIXUP_REQUIRED int error; /* Call the cpu specific prefetch abort fixup routine */ error = cpu_prefetchabt_fixup(tf); if (__predict_true(error != ABORT_FIXUP_FAILED)) return (error); /* * Oops, couldn't fix up the instruction */ printf( "prefetch_abort_fixup: fixup for %s mode prefetch abort failed.\n", TRAP_USERMODE(tf) ? "user" : "kernel"); printf("pc = 0x%08x, opcode 0x%08x, insn = ", tf->tf_pc, *((u_int *)tf->tf_pc)); disassemble(tf->tf_pc); /* Die now if this happened in kernel mode */ if (!TRAP_USERMODE(tf)) dab_fatal(tf, 0, tf->tf_pc, NULL, ksig); return (error); #else return (ABORT_FIXUP_OK); #endif /* CPU_ABORT_FIXUP_REQUIRED */ }
/* * dab_fatal() handles the following data aborts: * * FAULT_WRTBUF_0 - Vector Exception * FAULT_WRTBUF_1 - Terminal Exception * * We should never see these on a properly functioning system. * * This function is also called by the other handlers if they * detect a fatal problem. * * Note: If 'l' is NULL, we assume we're dealing with a prefetch abort. */ static int dab_fatal(struct trapframe *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig) { const char *mode; #ifdef KDTRACE_HOOKS if (!TRAP_USERMODE(tf)) { if (dtrace_trap_func != NULL && (*dtrace_trap_func)(tf, far & FAULT_TYPE_MASK)) return (0); } #endif mode = TRAP_USERMODE(tf) ? "user" : "kernel"; disable_interrupts(PSR_I|PSR_F); if (td != NULL) { printf("Fatal %s mode data abort: '%s'\n", mode, data_aborts[fsr & FAULT_TYPE_MASK].desc); printf("trapframe: %p\nFSR=%08x, FAR=", tf, fsr); if ((fsr & FAULT_IMPRECISE) == 0) printf("%08x, ", far); else printf("Invalid, "); printf("spsr=%08x\n", tf->tf_spsr); } else { printf("Fatal %s mode prefetch abort at 0x%08x\n", mode, tf->tf_pc); printf("trapframe: %p, spsr=%08x\n", tf, tf->tf_spsr); } printf("r0 =%08x, r1 =%08x, r2 =%08x, r3 =%08x\n", tf->tf_r0, tf->tf_r1, tf->tf_r2, tf->tf_r3); printf("r4 =%08x, r5 =%08x, r6 =%08x, r7 =%08x\n", tf->tf_r4, tf->tf_r5, tf->tf_r6, tf->tf_r7); printf("r8 =%08x, r9 =%08x, r10=%08x, r11=%08x\n", tf->tf_r8, tf->tf_r9, tf->tf_r10, tf->tf_r11); printf("r12=%08x, ", tf->tf_r12); if (TRAP_USERMODE(tf)) printf("usp=%08x, ulr=%08x", tf->tf_usr_sp, tf->tf_usr_lr); else printf("ssp=%08x, slr=%08x", tf->tf_svc_sp, tf->tf_svc_lr); printf(", pc =%08x\n\n", tf->tf_pc); #ifdef KDB if (debugger_on_panic || kdb_active) if (kdb_trap(fsr, 0, tf)) return (0); #endif panic("Fatal abort"); /*NOTREACHED*/ }
/* * dab_align() handles the following data aborts: * * FAULT_ALIGN_0 - Alignment fault * FAULT_ALIGN_1 - Alignment fault * * These faults are fatal if they happen in kernel mode. Otherwise, we * deliver a bus error to the process. */ static int dab_align(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig) { /* Alignment faults are always fatal if they occur in kernel mode */ if (!TRAP_USERMODE(tf)) { if (!td || !td->td_pcb->pcb_onfault) dab_fatal(tf, fsr, far, td, ksig); tf->tf_r0 = EFAULT; tf->tf_pc = (int)td->td_pcb->pcb_onfault; return (0); } /* pcb_onfault *must* be NULL at this point */ /* See if the cpu state needs to be fixed up */ (void) data_abort_fixup(tf, fsr, far, td, ksig); /* Deliver a bus error signal to the process */ ksig->code = 0; ksig->signb = SIGBUS; td->td_frame = tf; return (1); }
/* * dab_fatal() handles the following data aborts: * * FAULT_WRTBUF_0 - Vector Exception * FAULT_WRTBUF_1 - Terminal Exception * * We should never see these on a properly functioning system. * * This function is also called by the other handlers if they * detect a fatal problem. * * Note: If 'l' is NULL, we assume we're dealing with a prefetch abort. */ static int dab_fatal(trapframe_t *tf, u_int fsr, u_int far, struct lwp *l, ksiginfo_t *ksi) { const char * const mode = TRAP_USERMODE(tf) ? "user" : "kernel"; if (l != NULL) { printf("Fatal %s mode data abort: '%s'\n", mode, data_aborts[fsr & FAULT_TYPE_MASK].desc); printf("trapframe: %p\nFSR=%08x, FAR=", tf, fsr); if ((fsr & FAULT_IMPRECISE) == 0) printf("%08x, ", far); else printf("Invalid, "); printf("spsr=%08x\n", tf->tf_spsr); } else { printf("Fatal %s mode prefetch abort at 0x%08x\n", mode, tf->tf_pc); printf("trapframe: %p, spsr=%08x\n", tf, tf->tf_spsr); } printf("r0 =%08x, r1 =%08x, r2 =%08x, r3 =%08x\n", tf->tf_r0, tf->tf_r1, tf->tf_r2, tf->tf_r3); printf("r4 =%08x, r5 =%08x, r6 =%08x, r7 =%08x\n", tf->tf_r4, tf->tf_r5, tf->tf_r6, tf->tf_r7); printf("r8 =%08x, r9 =%08x, r10=%08x, r11=%08x\n", tf->tf_r8, tf->tf_r9, tf->tf_r10, tf->tf_r11); printf("r12=%08x, ", tf->tf_r12); if (TRAP_USERMODE(tf)) printf("usp=%08x, ulr=%08x", tf->tf_usr_sp, tf->tf_usr_lr); else printf("ssp=%08x, slr=%08x", tf->tf_svc_sp, tf->tf_svc_lr); printf(", pc =%08x\n\n", tf->tf_pc); #if defined(DDB) || defined(KGDB) kdb_trap(T_FAULT, tf); #endif panic("Fatal abort"); /*NOTREACHED*/ }
static inline int prefetch_abort_fixup(trapframe_t *tf) { #ifdef CPU_ABORT_FIXUP_REQUIRED int error; /* Call the CPU specific prefetch abort fixup routine */ error = cpu_prefetchabt_fixup(tf); if (__predict_true(error != ABORT_FIXUP_FAILED)) return (error); /* * Oops, couldn't fix up the instruction */ printf("%s: fixup for %s mode prefetch abort failed.\n", __func__, TRAP_USERMODE(tf) ? "user" : "kernel"); #ifdef THUMB_CODE if (tf->tf_spsr & PSR_T_bit) { printf("pc = 0x%08x, opcode 0x%04x, 0x%04x, insn = ", tf->tf_pc, *((uint16 *)(tf->tf_pc & ~1)), *((uint16 *)((tf->tf_pc + 2) & ~1))); } else #endif { printf("pc = 0x%08x, opcode 0x%08x, insn = ", tf->tf_pc, *((u_int *)tf->tf_pc)); } disassemble(tf->tf_pc); /* Die now if this happened in kernel mode */ if (!TRAP_USERMODE(tf)) dab_fatal(tf, 0, tf->tf_pc, NULL, NULL); return (error); #else return (ABORT_FIXUP_OK); #endif /* CPU_ABORT_FIXUP_REQUIRED */ }
void data_abort_handler(struct trapframe *tf) { struct lwp * const l = curlwp; struct proc * const p = l->l_proc; vm_prot_t atype; bool usrmode, twopages; struct vm_map *map; vaddr_t va; vsize_t asize; /* * Data aborts in kernel mode are possible (copyout etc), so * we hope the compiler (or programmer) has ensured that * R14_svc gets saved. * * We may need to fix up an STM or LDM instruction. This * involves seeing if the base was being written back, and if * so resetting it (by counting the number of registers being * transferred) before retrying (ARM 2 ds pp 10 & 33). */ /* Enable interrupts if they were enabled before the trap. */ if ((tf->tf_r15 & R15_IRQ_DISABLE) == 0) int_on(); curcpu()->ci_data.cpu_ntrap++; if ((tf->tf_r15 & R15_MODE) == R15_MODE_USR) { lwp_settrapframe(l, tf); LWP_CACHE_CREDS(l, p); } data_abort_fixup(tf); va = data_abort_address(tf, &asize); atype = data_abort_atype(tf); usrmode = data_abort_usrmode(tf); twopages = (trunc_page(va) != round_page(va + asize) - PAGE_SIZE); if (!usrmode && va >= VM_MIN_KERNEL_ADDRESS) map = kernel_map; else map = &p->p_vmspace->vm_map; do_fault(tf, l, map, va, atype); if (twopages) do_fault(tf, l, map, va + asize - 4, atype); if (TRAP_USERMODE(tf)) userret(l); }
void prefetch_abort_handler(struct trapframe *tf) { struct lwp * const l = curlwp; struct proc * const p = l->l_proc; /* Enable interrupts if they were enabled before the trap. */ if ((tf->tf_r15 & R15_IRQ_DISABLE) == 0) int_on(); /* * XXX Not done yet: * Check if the page being requested is already present. If * so, call the undefined instruction handler instead (ARM3 ds * p15). */ curcpu()->ci_data.cpu_ntrap++; if (TRAP_USERMODE(tf)) { lwp_settrapframe(l, tf); LWP_CACHE_CREDS(l, p); } else { #ifdef DDB db_printf("Prefetch abort in kernel mode\n"); kdb_trap(T_FAULT, tf); #else #ifdef DEBUG printf("Prefetch abort:\n"); printregs(tf); #endif panic("prefetch abort in kernel mode"); #endif } /* User-mode prefetch abort */ vaddr_t pc = tf->tf_r15 & R15_PC; do_fault(tf, l, &p->p_vmspace->vm_map, pc, VM_PROT_EXECUTE); userret(l); }
/* * dab_align() handles the following data aborts: * * FAULT_ALIGN_0 - Alignment fault * FAULT_ALIGN_0 - Alignment fault * * These faults are fatal if they happen in kernel mode. Otherwise, we * deliver a bus error to the process. */ static int dab_align(trapframe_t *tf, u_int fsr, u_int far, struct lwp *l, ksiginfo_t *ksi) { /* Alignment faults are always fatal if they occur in kernel mode */ if (!TRAP_USERMODE(tf)) dab_fatal(tf, fsr, far, l, NULL); /* pcb_onfault *must* be NULL at this point */ KDASSERT(((struct pcb *)lwp_getpcb(l))->pcb_onfault == NULL); /* See if the CPU state needs to be fixed up */ (void) data_abort_fixup(tf, fsr, far, l); /* Deliver a bus error signal to the process */ KSI_INIT_TRAP(ksi); ksi->ksi_signo = SIGBUS; ksi->ksi_code = BUS_ADRALN; ksi->ksi_addr = (uint32_t *)(intptr_t)far; ksi->ksi_trap = fsr; lwp_settrapframe(l, tf); return (1); }
/* * void prefetch_abort_handler(struct trapframe *tf) * * Abort handler called when instruction execution occurs at * a non existent or restricted (access permissions) memory page. * If the address is invalid and we were in SVC mode then panic as * the kernel should never prefetch abort. * If the address is invalid and the page is mapped then the user process * does no have read permission so send it a signal. * Otherwise fault the page in and try again. */ static void prefetch_abort_handler(struct trapframe *tf) { struct thread *td; struct proc * p; struct vm_map *map; vm_offset_t fault_pc, va; int error = 0; struct ksig ksig; #if 0 /* Update vmmeter statistics */ uvmexp.traps++; #endif #if 0 printf("prefetch abort handler: %p %p\n", (void*)tf->tf_pc, (void*)tf->tf_usr_lr); #endif td = curthread; p = td->td_proc; PCPU_INC(cnt.v_trap); if (TRAP_USERMODE(tf)) { td->td_frame = tf; if (td->td_cowgen != td->td_proc->p_cowgen) thread_cow_update(td); } fault_pc = tf->tf_pc; if (td->td_md.md_spinlock_count == 0) { if (__predict_true(tf->tf_spsr & PSR_I) == 0) enable_interrupts(PSR_I); if (__predict_true(tf->tf_spsr & PSR_F) == 0) enable_interrupts(PSR_F); } /* Prefetch aborts cannot happen in kernel mode */ if (__predict_false(!TRAP_USERMODE(tf))) dab_fatal(tf, 0, tf->tf_pc, NULL, &ksig); td->td_pticks = 0; /* Ok validate the address, can only execute in USER space */ if (__predict_false(fault_pc >= VM_MAXUSER_ADDRESS || (fault_pc < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW))) { ksig.signb = SIGSEGV; ksig.code = 0; goto do_trapsignal; } map = &td->td_proc->p_vmspace->vm_map; va = trunc_page(fault_pc); /* * See if the pmap can handle this fault on its own... */ #ifdef DEBUG last_fault_code = -1; #endif if (pmap_fault_fixup(map->pmap, va, VM_PROT_READ, 1)) goto out; error = vm_fault(map, va, VM_PROT_READ | VM_PROT_EXECUTE, VM_FAULT_NORMAL); if (__predict_true(error == 0)) goto out; if (error == ENOMEM) { printf("VM: pid %d (%s), uid %d killed: " "out of swap\n", td->td_proc->p_pid, td->td_name, (td->td_proc->p_ucred) ? td->td_proc->p_ucred->cr_uid : -1); ksig.signb = SIGKILL; } else { ksig.signb = SIGSEGV; } ksig.code = 0; do_trapsignal: call_trapsignal(td, ksig.signb, ksig.code); out: userret(td, tf); }
/* * dab_buserr() handles the following data aborts: * * FAULT_BUSERR_0 - External Abort on Linefetch -- Section * FAULT_BUSERR_1 - External Abort on Linefetch -- Page * FAULT_BUSERR_2 - External Abort on Non-linefetch -- Section * FAULT_BUSERR_3 - External Abort on Non-linefetch -- Page * FAULT_BUSTRNL1 - External abort on Translation -- Level 1 * FAULT_BUSTRNL2 - External abort on Translation -- Level 2 * * If pcb_onfault is set, flag the fault and return to the handler. * If the fault occurred in user mode, give the process a SIGBUS. * * Note: On XScale, FAULT_BUSERR_0, FAULT_BUSERR_1, and FAULT_BUSERR_2 * can be flagged as imprecise in the FSR. This causes a real headache * since some of the machine state is lost. In this case, tf->tf_pc * may not actually point to the offending instruction. In fact, if * we've taken a double abort fault, it generally points somewhere near * the top of "data_abort_entry" in exception.S. * * In all other cases, these data aborts are considered fatal. */ static int dab_buserr(struct trapframe *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig) { struct pcb *pcb = td->td_pcb; #ifdef __XSCALE__ if ((fsr & FAULT_IMPRECISE) != 0 && (tf->tf_spsr & PSR_MODE) == PSR_ABT32_MODE) { /* * Oops, an imprecise, double abort fault. We've lost the * r14_abt/spsr_abt values corresponding to the original * abort, and the spsr saved in the trapframe indicates * ABT mode. */ tf->tf_spsr &= ~PSR_MODE; /* * We use a simple heuristic to determine if the double abort * happened as a result of a kernel or user mode access. * If the current trapframe is at the top of the kernel stack, * the fault _must_ have come from user mode. */ if (tf != ((struct trapframe *)pcb->pcb_regs.sf_sp) - 1) { /* * Kernel mode. We're either about to die a * spectacular death, or pcb_onfault will come * to our rescue. Either way, the current value * of tf->tf_pc is irrelevant. */ tf->tf_spsr |= PSR_SVC32_MODE; if (pcb->pcb_onfault == NULL) printf("\nKernel mode double abort!\n"); } else { /* * User mode. We've lost the program counter at the * time of the fault (not that it was accurate anyway; * it's not called an imprecise fault for nothing). * About all we can do is copy r14_usr to tf_pc and * hope for the best. The process is about to get a * SIGBUS, so it's probably history anyway. */ tf->tf_spsr |= PSR_USR32_MODE; tf->tf_pc = tf->tf_usr_lr; } } /* FAR is invalid for imprecise exceptions */ if ((fsr & FAULT_IMPRECISE) != 0) far = 0; #endif /* __XSCALE__ */ if (pcb->pcb_onfault) { tf->tf_r0 = EFAULT; tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; return (0); } /* * At this point, if the fault happened in kernel mode, we're toast */ if (!TRAP_USERMODE(tf)) dab_fatal(tf, fsr, far, td, ksig); /* Deliver a bus error signal to the process */ ksig->signb = SIGBUS; ksig->code = 0; td->td_frame = tf; return (1); }
void abort_handler(struct trapframe *tf, int type) { struct vm_map *map; struct pcb *pcb; struct thread *td; u_int user, far, fsr; vm_prot_t ftype; void *onfault; vm_offset_t va; int error = 0; struct ksig ksig; struct proc *p; if (type == 1) return (prefetch_abort_handler(tf)); /* Grab FAR/FSR before enabling interrupts */ far = cpu_faultaddress(); fsr = cpu_faultstatus(); #if 0 printf("data abort: fault address=%p (from pc=%p lr=%p)\n", (void*)far, (void*)tf->tf_pc, (void*)tf->tf_svc_lr); #endif /* Update vmmeter statistics */ #if 0 vmexp.traps++; #endif td = curthread; p = td->td_proc; PCPU_INC(cnt.v_trap); /* Data abort came from user mode? */ user = TRAP_USERMODE(tf); if (user) { td->td_pticks = 0; td->td_frame = tf; if (td->td_cowgen != td->td_proc->p_cowgen) thread_cow_update(td); } /* Grab the current pcb */ pcb = td->td_pcb; /* Re-enable interrupts if they were enabled previously */ if (td->td_md.md_spinlock_count == 0) { if (__predict_true(tf->tf_spsr & PSR_I) == 0) enable_interrupts(PSR_I); if (__predict_true(tf->tf_spsr & PSR_F) == 0) enable_interrupts(PSR_F); } /* Invoke the appropriate handler, if necessary */ if (__predict_false(data_aborts[fsr & FAULT_TYPE_MASK].func != NULL)) { if ((data_aborts[fsr & FAULT_TYPE_MASK].func)(tf, fsr, far, td, &ksig)) { 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. */ /* * 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. * XXX: It would be nice to be able to support Thumb at some point. */ if (__predict_false((tf->tf_pc & 3) != 0)) { if (user) { /* * Give the user an illegal instruction signal. */ /* Deliver a SIGILL to the process */ ksig.signb = SIGILL; ksig.code = 0; goto do_trapsignal; } /* * The kernel never executes Thumb code. */ printf("\ndata_abort_fault: Misaligned Kernel-mode " "Program Counter\n"); dab_fatal(tf, fsr, far, td, &ksig); } va = trunc_page((vm_offset_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 == 0 && (va >= VM_MIN_KERNEL_ADDRESS || (va < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW)) && __predict_true((pcb->pcb_onfault == NULL || (ReadWord(tf->tf_pc) & 0x05200000) != 0x04200000))) { map = kernel_map; /* Was the fault due to the FPE/IPKDB ? */ if (__predict_false((tf->tf_spsr & PSR_MODE)==PSR_UND32_MODE)) { /* * 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 = 1; ksig.signb = SIGSEGV; ksig.code = 0; goto do_trapsignal; } } else { map = &td->td_proc->p_vmspace->vm_map; } /* * We need to know whether the page should be mapped as R or R/W. * On armv4, the fault status register does not indicate whether * the access was a read or write. 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 faulting instruction to determine if it was a write. */ if (IS_PERMISSION_FAULT(fsr)) ftype = VM_PROT_WRITE; else { u_int insn = ReadWord(tf->tf_pc); if (((insn & 0x0c100000) == 0x04000000) || /* STR/STRB */ ((insn & 0x0e1000b0) == 0x000000b0) || /* STRH/STRD */ ((insn & 0x0a100000) == 0x08000000)) { /* STM/CDT */ 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 (td->td_critnest != 0 || WITNESS_CHECK(WARN_SLEEPOK | WARN_GIANTOK, NULL, "Kernel page fault") != 0) goto fatal_pagefault; if (pmap_fault_fixup(vmspace_pmap(td->td_proc->p_vmspace), va, ftype, user)) { goto out; } onfault = pcb->pcb_onfault; pcb->pcb_onfault = NULL; error = vm_fault(map, va, ftype, VM_FAULT_NORMAL); pcb->pcb_onfault = onfault; if (__predict_true(error == 0)) goto out; fatal_pagefault: if (user == 0) { if (pcb->pcb_onfault) { tf->tf_r0 = error; tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; return; } printf("\nvm_fault(%p, %x, %x, 0) -> %x\n", map, va, ftype, error); dab_fatal(tf, fsr, far, td, &ksig); } if (error == ENOMEM) { printf("VM: pid %d (%s), uid %d killed: " "out of swap\n", td->td_proc->p_pid, td->td_name, (td->td_proc->p_ucred) ? td->td_proc->p_ucred->cr_uid : -1); ksig.signb = SIGKILL; } else { ksig.signb = SIGSEGV; } ksig.code = 0; do_trapsignal: call_trapsignal(td, ksig.signb, ksig.code); out: /* If returning to user mode, make sure to invoke userret() */ if (user) userret(td, tf); }
/* * void prefetch_abort_handler(trapframe_t *tf) * * Abort handler called when instruction execution occurs at * a non existent or restricted (access permissions) memory page. * If the address is invalid and we were in SVC mode then panic as * the kernel should never prefetch abort. * If the address is invalid and the page is mapped then the user process * does no have read permission so send it a signal. * Otherwise fault the page in and try again. */ void prefetch_abort_handler(trapframe_t *tf) { struct thread *td; struct proc * p; struct vm_map *map; vm_offset_t fault_pc, va; int error = 0; struct ksig ksig; #if 0 /* Update vmmeter statistics */ uvmexp.traps++; #endif #if 0 printf("prefetch abort handler: %p %p\n", (void*)tf->tf_pc, (void*)tf->tf_usr_lr); #endif td = curthread; p = td->td_proc; PCPU_INC(cnt.v_trap); if (TRAP_USERMODE(tf)) { td->td_frame = tf; if (td->td_ucred != td->td_proc->p_ucred) cred_update_thread(td); } fault_pc = tf->tf_pc; if (td->td_md.md_spinlock_count == 0) { if (__predict_true(tf->tf_spsr & I32_bit) == 0) enable_interrupts(I32_bit); if (__predict_true(tf->tf_spsr & F32_bit) == 0) enable_interrupts(F32_bit); } /* See if the cpu state needs to be fixed up */ switch (prefetch_abort_fixup(tf, &ksig)) { case ABORT_FIXUP_RETURN: return; case ABORT_FIXUP_FAILED: /* Deliver a SIGILL to the process */ ksig.signb = SIGILL; ksig.code = 0; td->td_frame = tf; goto do_trapsignal; default: break; } /* Prefetch aborts cannot happen in kernel mode */ if (__predict_false(!TRAP_USERMODE(tf))) dab_fatal(tf, 0, tf->tf_pc, NULL, &ksig); td->td_pticks = 0; /* Ok validate the address, can only execute in USER space */ if (__predict_false(fault_pc >= VM_MAXUSER_ADDRESS || (fault_pc < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW))) { ksig.signb = SIGSEGV; ksig.code = 0; goto do_trapsignal; } map = &td->td_proc->p_vmspace->vm_map; va = trunc_page(fault_pc); /* * See if the pmap can handle this fault on its own... */ #ifdef DEBUG last_fault_code = -1; #endif if (pmap_fault_fixup(map->pmap, va, VM_PROT_READ, 1)) goto out; if (map != kernel_map) { PROC_LOCK(p); p->p_lock++; PROC_UNLOCK(p); } error = vm_fault(map, va, VM_PROT_READ | VM_PROT_EXECUTE, VM_FAULT_NORMAL); if (map != kernel_map) { PROC_LOCK(p); p->p_lock--; PROC_UNLOCK(p); } if (__predict_true(error == 0)) goto out; if (error == ENOMEM) { printf("VM: pid %d (%s), uid %d killed: " "out of swap\n", td->td_proc->p_pid, td->td_name, (td->td_proc->p_ucred) ? td->td_proc->p_ucred->cr_uid : -1); ksig.signb = SIGKILL; } else { ksig.signb = SIGSEGV; } ksig.code = 0; do_trapsignal: call_trapsignal(td, ksig.signb, ksig.code); out: userret(td, tf); }
/* * void prefetch_abort_handler(trapframe_t *tf) * * Abort handler called when instruction execution occurs at * a non existent or restricted (access permissions) memory page. * If the address is invalid and we were in SVC mode then panic as * the kernel should never prefetch abort. * If the address is invalid and the page is mapped then the user process * does no have read permission so send it a signal. * Otherwise fault the page in and try again. */ void prefetch_abort_handler(trapframe_t *tf) { struct lwp *l; struct pcb *pcb __diagused; struct vm_map *map; vaddr_t fault_pc, va; ksiginfo_t ksi; int error, user; UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); /* Update vmmeter statistics */ curcpu()->ci_data.cpu_ntrap++; l = curlwp; pcb = lwp_getpcb(l); if ((user = TRAP_USERMODE(tf)) != 0) LWP_CACHE_CREDS(l, l->l_proc); /* * Enable IRQ's (disabled by the abort) This always comes * from user mode so we know interrupts were not disabled. * But we check anyway. */ KASSERT(!TRAP_USERMODE(tf) || (tf->tf_spsr & IF32_bits) == 0); if (__predict_true((tf->tf_spsr & I32_bit) != IF32_bits)) restore_interrupts(tf->tf_spsr & IF32_bits); /* See if the CPU state needs to be fixed up */ switch (prefetch_abort_fixup(tf)) { case ABORT_FIXUP_RETURN: KASSERT(!TRAP_USERMODE(tf) || (tf->tf_spsr & IF32_bits) == 0); 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) tf->tf_pc; lwp_settrapframe(l, tf); goto do_trapsignal; default: break; } /* Prefetch aborts cannot happen in kernel mode */ if (__predict_false(!user)) dab_fatal(tf, 0, tf->tf_pc, NULL, NULL); /* Get fault address */ fault_pc = tf->tf_pc; lwp_settrapframe(l, tf); UVMHIST_LOG(maphist, " (pc=0x%x, l=0x%x, tf=0x%x)", fault_pc, l, tf, 0); /* Ok validate the address, can only execute in USER space */ if (__predict_false(fault_pc >= VM_MAXUSER_ADDRESS || (fault_pc < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW))) { KSI_INIT_TRAP(&ksi); ksi.ksi_signo = SIGSEGV; ksi.ksi_code = SEGV_ACCERR; ksi.ksi_addr = (uint32_t *)(intptr_t) fault_pc; ksi.ksi_trap = fault_pc; goto do_trapsignal; } map = &l->l_proc->p_vmspace->vm_map; va = trunc_page(fault_pc); /* * See if the pmap can handle this fault on its own... */ #ifdef DEBUG last_fault_code = -1; #endif if (pmap_fault_fixup(map->pmap, va, VM_PROT_READ|VM_PROT_EXECUTE, 1)) { UVMHIST_LOG (maphist, " <- emulated", 0, 0, 0, 0); goto out; } #ifdef DIAGNOSTIC if (__predict_false(curcpu()->ci_intr_depth > 0)) { printf("\nNon-emulated prefetch abort with intr_depth > 0\n"); dab_fatal(tf, 0, tf->tf_pc, NULL, NULL); } #endif KASSERT(pcb->pcb_onfault == NULL); error = uvm_fault(map, va, VM_PROT_READ|VM_PROT_EXECUTE); if (__predict_true(error == 0)) { UVMHIST_LOG (maphist, " <- uvm", 0, 0, 0, 0); goto out; } KSI_INIT_TRAP(&ksi); UVMHIST_LOG (maphist, " <- fatal (%d)", error, 0, 0, 0); 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 = SEGV_MAPERR; ksi.ksi_addr = (uint32_t *)(intptr_t) fault_pc; ksi.ksi_trap = fault_pc; do_trapsignal: call_trapsignal(l, tf, &ksi); out: KASSERT(!TRAP_USERMODE(tf) || (tf->tf_spsr & IF32_bits) == 0); userret(l); }
/* * dab_buserr() handles the following data aborts: * * FAULT_BUSERR_0 - External Abort on Linefetch -- Section * FAULT_BUSERR_1 - External Abort on Linefetch -- Page * FAULT_BUSERR_2 - External Abort on Non-linefetch -- Section * FAULT_BUSERR_3 - External Abort on Non-linefetch -- Page * FAULT_BUSTRNL1 - External abort on Translation -- Level 1 * FAULT_BUSTRNL2 - External abort on Translation -- Level 2 * * If pcb_onfault is set, flag the fault and return to the handler. * If the fault occurred in user mode, give the process a SIGBUS. * * Note: On XScale, FAULT_BUSERR_0, FAULT_BUSERR_1, and FAULT_BUSERR_2 * can be flagged as imprecise in the FSR. This causes a real headache * since some of the machine state is lost. In this case, tf->tf_pc * may not actually point to the offending instruction. In fact, if * we've taken a double abort fault, it generally points somewhere near * the top of "data_abort_entry" in exception.S. * * In all other cases, these data aborts are considered fatal. */ static int dab_buserr(trapframe_t *tf, u_int fsr, u_int far, struct lwp *l, ksiginfo_t *ksi) { struct pcb *pcb = lwp_getpcb(l); #ifdef __XSCALE__ if ((fsr & FAULT_IMPRECISE) != 0 && (tf->tf_spsr & PSR_MODE) == PSR_ABT32_MODE) { /* * Oops, an imprecise, double abort fault. We've lost the * r14_abt/spsr_abt values corresponding to the original * abort, and the spsr saved in the trapframe indicates * ABT mode. */ tf->tf_spsr &= ~PSR_MODE; /* * We use a simple heuristic to determine if the double abort * happened as a result of a kernel or user mode access. * If the current trapframe is at the top of the kernel stack, * the fault _must_ have come from user mode. */ if (tf != ((trapframe_t *)pcb->pcb_ksp) - 1) { /* * Kernel mode. We're either about to die a * spectacular death, or pcb_onfault will come * to our rescue. Either way, the current value * of tf->tf_pc is irrelevant. */ tf->tf_spsr |= PSR_SVC32_MODE; if (pcb->pcb_onfault == NULL) printf("\nKernel mode double abort!\n"); } else { /* * User mode. We've lost the program counter at the * time of the fault (not that it was accurate anyway; * it's not called an imprecise fault for nothing). * About all we can do is copy r14_usr to tf_pc and * hope for the best. The process is about to get a * SIGBUS, so it's probably history anyway. */ tf->tf_spsr |= PSR_USR32_MODE; tf->tf_pc = tf->tf_usr_lr; #ifdef THUMB_CODE tf->tf_spsr &= ~PSR_T_bit; if (tf->tf_usr_lr & 1) tf->tf_spsr |= PSR_T_bit; #endif } } /* FAR is invalid for imprecise exceptions */ if ((fsr & FAULT_IMPRECISE) != 0) far = 0; #endif /* __XSCALE__ */ if (pcb->pcb_onfault) { KDASSERT(TRAP_USERMODE(tf) == 0); tf->tf_r0 = EFAULT; tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault; return (0); } /* See if the CPU state needs to be fixed up */ (void) data_abort_fixup(tf, fsr, far, l); /* * At this point, if the fault happened in kernel mode, we're toast */ if (!TRAP_USERMODE(tf)) dab_fatal(tf, fsr, far, l, NULL); /* Deliver a bus error signal to the process */ KSI_INIT_TRAP(ksi); ksi->ksi_signo = SIGBUS; ksi->ksi_code = BUS_ADRERR; ksi->ksi_addr = (uint32_t *)(intptr_t)far; ksi->ksi_trap = fsr; lwp_settrapframe(l, tf); return (1); }
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); } }