void swi_handler(trapframe_t *frame) { struct thread *td = curthread; td->td_frame = frame; td->td_pticks = 0; /* * Make sure the program counter is correctly aligned so we * don't take an alignment fault trying to read the opcode. */ if (__predict_false(((frame->tf_pc - INSN_SIZE) & 3) != 0)) { call_trapsignal(td, SIGILL, 0); userret(td, frame); return; } /* * Enable interrupts if they were enabled before the exception. * Since all syscalls *should* come from user mode it will always * be safe to enable them, but check anyway. */ if (td->td_md.md_spinlock_count == 0) { if (__predict_true(frame->tf_spsr & I32_bit) == 0) enable_interrupts(I32_bit); if (__predict_true(frame->tf_spsr & F32_bit) == 0) enable_interrupts(F32_bit); } syscall(td, frame); }
/* * abort_debug() handles the following abort: * * FAULT_DEBUG - Debug Event * */ static __inline void abort_debug(struct trapframe *tf, u_int fsr, u_int prefetch, u_int usermode, u_int far) { if (usermode) { struct thread *td; td = curthread; call_trapsignal(td, SIGTRAP, TRAP_BRKPT, far); userret(td, tf); } else { #ifdef KDB kdb_trap(T_BREAKPOINT, 0, tf); #else printf("No debugger in kernel.\n"); #endif } }
static void syscall(struct thread *td, trapframe_t *frame) { struct syscall_args sa; int error; #ifndef __ARM_EABI__ sa.insn = *(uint32_t *)(frame->tf_pc - INSN_SIZE); switch (sa.insn & SWI_OS_MASK) { case 0: /* XXX: we need our own one. */ break; default: call_trapsignal(td, SIGILL, 0); userret(td, frame); return; } #endif sa.nap = 4; error = syscallenter(td, &sa); KASSERT(error != 0 || td->td_ar == NULL, ("returning from syscall with td_ar set!")); syscallret(td, error, &sa); }
/* * 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); }
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); }
/* * Abort handler. * * FAR, FSR, and everything what can be lost after enabling * interrupts must be grabbed before the interrupts will be * enabled. Note that when interrupts will be enabled, we * could even migrate to another CPU ... * * TODO: move quick cases to ASM */ void abort_handler(struct trapframe *tf, int prefetch) { struct thread *td; vm_offset_t far, va; int idx, rv; uint32_t fsr; struct ksig ksig; struct proc *p; struct pcb *pcb; struct vm_map *map; struct vmspace *vm; vm_prot_t ftype; bool usermode; #ifdef INVARIANTS void *onfault; #endif td = curthread; fsr = (prefetch) ? cp15_ifsr_get(): cp15_dfsr_get(); #if __ARM_ARCH >= 7 far = (prefetch) ? cp15_ifar_get() : cp15_dfar_get(); #else far = (prefetch) ? TRAPF_PC(tf) : cp15_dfar_get(); #endif idx = FSR_TO_FAULT(fsr); usermode = TRAPF_USERMODE(tf); /* Abort came from user mode? */ if (usermode) td->td_frame = tf; CTR6(KTR_TRAP, "%s: fsr %#x (idx %u) far %#x prefetch %u usermode %d", __func__, fsr, idx, far, prefetch, usermode); /* * Firstly, handle aborts that are not directly related to mapping. */ if (__predict_false(idx == FAULT_EA_IMPREC)) { abort_imprecise(tf, fsr, prefetch, usermode); return; } if (__predict_false(idx == FAULT_DEBUG)) { abort_debug(tf, fsr, prefetch, usermode, far); return; } /* * ARM has a set of unprivileged load and store instructions * (LDRT/LDRBT/STRT/STRBT ...) which are supposed to be used in other * than user mode and OS should recognize their aborts and behave * appropriately. However, there is no way how to do that reasonably * in general unless we restrict the handling somehow. * * For now, these instructions are used only in copyin()/copyout() * like functions where usermode buffers are checked in advance that * they are not from KVA space. Thus, no action is needed here. */ #ifdef ARM_NEW_PMAP rv = pmap_fault(PCPU_GET(curpmap), far, fsr, idx, usermode); if (rv == 0) { return; } else if (rv == EFAULT) { call_trapsignal(td, SIGSEGV, SEGV_MAPERR, far); userret(td, tf); return; } #endif /* * Now, when we handled imprecise and debug aborts, the rest of * aborts should be really related to mapping. */ PCPU_INC(cnt.v_trap); #ifdef KDB if (kdb_active) { kdb_reenter(); goto out; } #endif if (__predict_false((td->td_pflags & TDP_NOFAULTING) != 0)) { /* * Due to both processor errata and lazy TLB invalidation when * access restrictions are removed from virtual pages, memory * accesses that are allowed by the physical mapping layer may * nonetheless cause one spurious page fault per virtual page. * When the thread is executing a "no faulting" section that * is bracketed by vm_fault_{disable,enable}_pagefaults(), * every page fault is treated as a spurious page fault, * unless it accesses the same virtual address as the most * recent page fault within the same "no faulting" section. */ if (td->td_md.md_spurflt_addr != far || (td->td_pflags & TDP_RESETSPUR) != 0) { td->td_md.md_spurflt_addr = far; td->td_pflags &= ~TDP_RESETSPUR; tlb_flush_local(far & ~PAGE_MASK); return; } } else { /* * If we get a page fault while in a critical section, then * it is most likely a fatal kernel page fault. The kernel * is already going to panic trying to get a sleep lock to * do the VM lookup, so just consider it a fatal trap so the * kernel can print out a useful trap message and even get * to the debugger. * * If we get a page fault while holding a non-sleepable * lock, then it is most likely a fatal kernel page fault. * If WITNESS is enabled, then it's going to whine about * bogus LORs with various VM locks, so just skip to the * fatal trap handling directly. */ if (td->td_critnest != 0 || WITNESS_CHECK(WARN_SLEEPOK | WARN_GIANTOK, NULL, "Kernel page fault") != 0) { abort_fatal(tf, idx, fsr, far, prefetch, td, &ksig); return; } } /* 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); } p = td->td_proc; if (usermode) { td->td_pticks = 0; if (td->td_cowgen != p->p_cowgen) thread_cow_update(td); } /* Invoke the appropriate handler, if necessary. */ if (__predict_false(aborts[idx].func != NULL)) { if ((aborts[idx].func)(tf, idx, fsr, far, prefetch, td, &ksig)) goto do_trapsignal; goto out; } /* * Don't pass faulting cache operation to vm_fault(). We don't want * to handle all vm stuff at this moment. */ pcb = td->td_pcb; if (__predict_false(pcb->pcb_onfault == cachebailout)) { tf->tf_r0 = far; /* return failing address */ tf->tf_pc = (register_t)pcb->pcb_onfault; return; } /* Handle remaining I-cache aborts. */ if (idx == FAULT_ICACHE) { if (abort_icache(tf, idx, fsr, far, prefetch, td, &ksig)) goto do_trapsignal; goto out; } /* * At this point, we're dealing with one of the following aborts: * * FAULT_TRAN_xx - Translation * FAULT_PERM_xx - Permission * * These are the main virtual memory-related faults signalled by * the MMU. */ /* fusubailout is used by [fs]uswintr to avoid page faulting. */ pcb = td->td_pcb; if (__predict_false(pcb->pcb_onfault == fusubailout)) { tf->tf_r0 = EFAULT; tf->tf_pc = (register_t)pcb->pcb_onfault; return; } va = trunc_page(far); if (va >= KERNBASE) { /* * Don't allow user-mode faults in kernel address space. */ if (usermode) goto nogo; map = kernel_map; } else { /* * This is a fault on non-kernel virtual memory. If curproc * is NULL or curproc->p_vmspace is NULL the fault is fatal. */ vm = (p != NULL) ? p->p_vmspace : NULL; if (vm == NULL) goto nogo; map = &vm->vm_map; if (!usermode && (td->td_intr_nesting_level != 0 || pcb->pcb_onfault == NULL)) { abort_fatal(tf, idx, fsr, far, prefetch, td, &ksig); return; } } ftype = (fsr & FSR_WNR) ? VM_PROT_WRITE : VM_PROT_READ; if (prefetch) ftype |= VM_PROT_EXECUTE; #ifdef DEBUG last_fault_code = fsr; #endif #ifndef ARM_NEW_PMAP if (pmap_fault_fixup(vmspace_pmap(td->td_proc->p_vmspace), va, ftype, usermode)) { goto out; } #endif #ifdef INVARIANTS onfault = pcb->pcb_onfault; pcb->pcb_onfault = NULL; #endif /* Fault in the page. */ rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL); #ifdef INVARIANTS pcb->pcb_onfault = onfault; #endif if (__predict_true(rv == KERN_SUCCESS)) goto out; nogo: if (!usermode) { if (td->td_intr_nesting_level == 0 && pcb->pcb_onfault != NULL) { tf->tf_r0 = rv; tf->tf_pc = (int)pcb->pcb_onfault; return; } CTR2(KTR_TRAP, "%s: vm_fault() failed with %d", __func__, rv); abort_fatal(tf, idx, fsr, far, prefetch, td, &ksig); return; } ksig.sig = SIGSEGV; ksig.code = (rv == KERN_PROTECTION_FAILURE) ? SEGV_ACCERR : SEGV_MAPERR; ksig.addr = far; do_trapsignal: call_trapsignal(td, ksig.sig, ksig.code, ksig.addr); out: if (usermode) 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); }
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); }