diff options
Diffstat (limited to 'arch/arm64/kernel/traps.c')
| -rw-r--r-- | arch/arm64/kernel/traps.c | 816 |
1 files changed, 816 insertions, 0 deletions
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c new file mode 100644 index 000000000..965595fe6 --- /dev/null +++ b/arch/arm64/kernel/traps.c @@ -0,0 +1,816 @@ +/* + * Based on arch/arm/kernel/traps.c + * + * Copyright (C) 1995-2009 Russell King + * Copyright (C) 2012 ARM Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/bug.h> +#include <linux/signal.h> +#include <linux/personality.h> +#include <linux/kallsyms.h> +#include <linux/spinlock.h> +#include <linux/uaccess.h> +#include <linux/hardirq.h> +#include <linux/kdebug.h> +#include <linux/module.h> +#include <linux/kexec.h> +#include <linux/delay.h> +#include <linux/init.h> +#include <linux/sched/signal.h> +#include <linux/sched/debug.h> +#include <linux/sched/task_stack.h> +#include <linux/sizes.h> +#include <linux/syscalls.h> +#include <linux/mm_types.h> + +#include <asm/atomic.h> +#include <asm/bug.h> +#include <asm/cpufeature.h> +#include <asm/daifflags.h> +#include <asm/debug-monitors.h> +#include <asm/esr.h> +#include <asm/insn.h> +#include <asm/traps.h> +#include <asm/smp.h> +#include <asm/stack_pointer.h> +#include <asm/stacktrace.h> +#include <asm/exception.h> +#include <asm/system_misc.h> +#include <asm/sysreg.h> + +static const char *handler[]= { + "Synchronous Abort", + "IRQ", + "FIQ", + "Error" +}; + +int show_unhandled_signals = 0; + +static void dump_backtrace_entry(unsigned long where) +{ + printk(" %pS\n", (void *)where); +} + +static void __dump_instr(const char *lvl, struct pt_regs *regs) +{ + unsigned long addr = instruction_pointer(regs); + char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str; + int i; + + for (i = -4; i < 1; i++) { + unsigned int val, bad; + + bad = get_user(val, &((u32 *)addr)[i]); + + if (!bad) + p += sprintf(p, i == 0 ? "(%08x) " : "%08x ", val); + else { + p += sprintf(p, "bad PC value"); + break; + } + } + printk("%sCode: %s\n", lvl, str); +} + +static void dump_instr(const char *lvl, struct pt_regs *regs) +{ + if (!user_mode(regs)) { + mm_segment_t fs = get_fs(); + set_fs(KERNEL_DS); + __dump_instr(lvl, regs); + set_fs(fs); + } else { + __dump_instr(lvl, regs); + } +} + +void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) +{ + struct stackframe frame; + int skip = 0; + + pr_debug("%s(regs = %p tsk = %p)\n", __func__, regs, tsk); + + if (regs) { + if (user_mode(regs)) + return; + skip = 1; + } + + if (!tsk) + tsk = current; + + if (!try_get_task_stack(tsk)) + return; + + if (tsk == current) { + frame.fp = (unsigned long)__builtin_frame_address(0); + frame.pc = (unsigned long)dump_backtrace; + } else { + /* + * task blocked in __switch_to + */ + frame.fp = thread_saved_fp(tsk); + frame.pc = thread_saved_pc(tsk); + } +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + frame.graph = tsk->curr_ret_stack; +#endif + + printk("Call trace:\n"); + do { + /* skip until specified stack frame */ + if (!skip) { + dump_backtrace_entry(frame.pc); + } else if (frame.fp == regs->regs[29]) { + skip = 0; + /* + * Mostly, this is the case where this function is + * called in panic/abort. As exception handler's + * stack frame does not contain the corresponding pc + * at which an exception has taken place, use regs->pc + * instead. + */ + dump_backtrace_entry(regs->pc); + } + } while (!unwind_frame(tsk, &frame)); + + put_task_stack(tsk); +} + +void show_stack(struct task_struct *tsk, unsigned long *sp) +{ + dump_backtrace(NULL, tsk); + barrier(); +} + +#ifdef CONFIG_PREEMPT +#define S_PREEMPT " PREEMPT" +#else +#define S_PREEMPT "" +#endif +#define S_SMP " SMP" + +static int __die(const char *str, int err, struct pt_regs *regs) +{ + struct task_struct *tsk = current; + static int die_counter; + int ret; + + pr_emerg("Internal error: %s: %x [#%d]" S_PREEMPT S_SMP "\n", + str, err, ++die_counter); + + /* trap and error numbers are mostly meaningless on ARM */ + ret = notify_die(DIE_OOPS, str, regs, err, 0, SIGSEGV); + if (ret == NOTIFY_STOP) + return ret; + + print_modules(); + pr_emerg("Process %.*s (pid: %d, stack limit = 0x%p)\n", + TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk), + end_of_stack(tsk)); + show_regs(regs); + + if (!user_mode(regs)) + dump_instr(KERN_EMERG, regs); + + return ret; +} + +static DEFINE_RAW_SPINLOCK(die_lock); + +/* + * This function is protected against re-entrancy. + */ +void die(const char *str, struct pt_regs *regs, int err) +{ + int ret; + unsigned long flags; + + raw_spin_lock_irqsave(&die_lock, flags); + + oops_enter(); + + console_verbose(); + bust_spinlocks(1); + ret = __die(str, err, regs); + + if (regs && kexec_should_crash(current)) + crash_kexec(regs); + + bust_spinlocks(0); + add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); + oops_exit(); + + if (in_interrupt()) + panic("Fatal exception in interrupt"); + if (panic_on_oops) + panic("Fatal exception"); + + raw_spin_unlock_irqrestore(&die_lock, flags); + + if (ret != NOTIFY_STOP) + do_exit(SIGSEGV); +} + +static bool show_unhandled_signals_ratelimited(void) +{ + static DEFINE_RATELIMIT_STATE(rs, DEFAULT_RATELIMIT_INTERVAL, + DEFAULT_RATELIMIT_BURST); + return show_unhandled_signals && __ratelimit(&rs); +} + +void arm64_force_sig_info(struct siginfo *info, const char *str, + struct task_struct *tsk) +{ + unsigned int esr = tsk->thread.fault_code; + struct pt_regs *regs = task_pt_regs(tsk); + + if (!unhandled_signal(tsk, info->si_signo)) + goto send_sig; + + if (!show_unhandled_signals_ratelimited()) + goto send_sig; + + pr_info("%s[%d]: unhandled exception: ", tsk->comm, task_pid_nr(tsk)); + if (esr) + pr_cont("%s, ESR 0x%08x, ", esr_get_class_string(esr), esr); + + pr_cont("%s", str); + print_vma_addr(KERN_CONT " in ", regs->pc); + pr_cont("\n"); + __show_regs(regs); + +send_sig: + force_sig_info(info->si_signo, info, tsk); +} + +void arm64_notify_die(const char *str, struct pt_regs *regs, + struct siginfo *info, int err) +{ + if (user_mode(regs)) { + WARN_ON(regs != current_pt_regs()); + current->thread.fault_address = 0; + current->thread.fault_code = err; + arm64_force_sig_info(info, str, current); + } else { + die(str, regs, err); + } +} + +void arm64_skip_faulting_instruction(struct pt_regs *regs, unsigned long size) +{ + regs->pc += size; + + /* + * If we were single stepping, we want to get the step exception after + * we return from the trap. + */ + if (user_mode(regs)) + user_fastforward_single_step(current); +} + +static LIST_HEAD(undef_hook); +static DEFINE_RAW_SPINLOCK(undef_lock); + +void register_undef_hook(struct undef_hook *hook) +{ + unsigned long flags; + + raw_spin_lock_irqsave(&undef_lock, flags); + list_add(&hook->node, &undef_hook); + raw_spin_unlock_irqrestore(&undef_lock, flags); +} + +void unregister_undef_hook(struct undef_hook *hook) +{ + unsigned long flags; + + raw_spin_lock_irqsave(&undef_lock, flags); + list_del(&hook->node); + raw_spin_unlock_irqrestore(&undef_lock, flags); +} + +static int call_undef_hook(struct pt_regs *regs) +{ + struct undef_hook *hook; + unsigned long flags; + u32 instr; + int (*fn)(struct pt_regs *regs, u32 instr) = NULL; + void __user *pc = (void __user *)instruction_pointer(regs); + + if (!user_mode(regs)) { + __le32 instr_le; + if (probe_kernel_address((__force __le32 *)pc, instr_le)) + goto exit; + instr = le32_to_cpu(instr_le); + } else if (compat_thumb_mode(regs)) { + /* 16-bit Thumb instruction */ + __le16 instr_le; + if (get_user(instr_le, (__le16 __user *)pc)) + goto exit; + instr = le16_to_cpu(instr_le); + if (aarch32_insn_is_wide(instr)) { + u32 instr2; + + if (get_user(instr_le, (__le16 __user *)(pc + 2))) + goto exit; + instr2 = le16_to_cpu(instr_le); + instr = (instr << 16) | instr2; + } + } else { + /* 32-bit ARM instruction */ + __le32 instr_le; + if (get_user(instr_le, (__le32 __user *)pc)) + goto exit; + instr = le32_to_cpu(instr_le); + } + + raw_spin_lock_irqsave(&undef_lock, flags); + list_for_each_entry(hook, &undef_hook, node) + if ((instr & hook->instr_mask) == hook->instr_val && + (regs->pstate & hook->pstate_mask) == hook->pstate_val) + fn = hook->fn; + + raw_spin_unlock_irqrestore(&undef_lock, flags); +exit: + return fn ? fn(regs, instr) : 1; +} + +void force_signal_inject(int signal, int code, unsigned long address) +{ + siginfo_t info; + const char *desc; + struct pt_regs *regs = current_pt_regs(); + + clear_siginfo(&info); + + switch (signal) { + case SIGILL: + desc = "undefined instruction"; + break; + case SIGSEGV: + desc = "illegal memory access"; + break; + default: + desc = "unknown or unrecoverable error"; + break; + } + + /* Force signals we don't understand to SIGKILL */ + if (WARN_ON(signal != SIGKILL && + siginfo_layout(signal, code) != SIL_FAULT)) { + signal = SIGKILL; + } + + info.si_signo = signal; + info.si_errno = 0; + info.si_code = code; + info.si_addr = (void __user *)address; + + arm64_notify_die(desc, regs, &info, 0); +} + +/* + * Set up process info to signal segmentation fault - called on access error. + */ +void arm64_notify_segfault(unsigned long addr) +{ + int code; + + down_read(¤t->mm->mmap_sem); + if (find_vma(current->mm, addr) == NULL) + code = SEGV_MAPERR; + else + code = SEGV_ACCERR; + up_read(¤t->mm->mmap_sem); + + force_signal_inject(SIGSEGV, code, addr); +} + +asmlinkage void __exception do_undefinstr(struct pt_regs *regs) +{ + /* check for AArch32 breakpoint instructions */ + if (!aarch32_break_handler(regs)) + return; + + if (call_undef_hook(regs) == 0) + return; + + force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc); + BUG_ON(!user_mode(regs)); +} + +void cpu_enable_cache_maint_trap(const struct arm64_cpu_capabilities *__unused) +{ + sysreg_clear_set(sctlr_el1, SCTLR_EL1_UCI, 0); +} + +#define __user_cache_maint(insn, address, res) \ + if (address >= user_addr_max()) { \ + res = -EFAULT; \ + } else { \ + uaccess_ttbr0_enable(); \ + asm volatile ( \ + "1: " insn ", %1\n" \ + " mov %w0, #0\n" \ + "2:\n" \ + " .pushsection .fixup,\"ax\"\n" \ + " .align 2\n" \ + "3: mov %w0, %w2\n" \ + " b 2b\n" \ + " .popsection\n" \ + _ASM_EXTABLE(1b, 3b) \ + : "=r" (res) \ + : "r" (address), "i" (-EFAULT)); \ + uaccess_ttbr0_disable(); \ + } + +static void user_cache_maint_handler(unsigned int esr, struct pt_regs *regs) +{ + unsigned long address; + int rt = (esr & ESR_ELx_SYS64_ISS_RT_MASK) >> ESR_ELx_SYS64_ISS_RT_SHIFT; + int crm = (esr & ESR_ELx_SYS64_ISS_CRM_MASK) >> ESR_ELx_SYS64_ISS_CRM_SHIFT; + int ret = 0; + + address = untagged_addr(pt_regs_read_reg(regs, rt)); + + switch (crm) { + case ESR_ELx_SYS64_ISS_CRM_DC_CVAU: /* DC CVAU, gets promoted */ + __user_cache_maint("dc civac", address, ret); + break; + case ESR_ELx_SYS64_ISS_CRM_DC_CVAC: /* DC CVAC, gets promoted */ + __user_cache_maint("dc civac", address, ret); + break; + case ESR_ELx_SYS64_ISS_CRM_DC_CVAP: /* DC CVAP */ + __user_cache_maint("sys 3, c7, c12, 1", address, ret); + break; + case ESR_ELx_SYS64_ISS_CRM_DC_CIVAC: /* DC CIVAC */ + __user_cache_maint("dc civac", address, ret); + break; + case ESR_ELx_SYS64_ISS_CRM_IC_IVAU: /* IC IVAU */ + __user_cache_maint("ic ivau", address, ret); + break; + default: + force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc); + return; + } + + if (ret) + arm64_notify_segfault(address); + else + arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE); +} + +static void ctr_read_handler(unsigned int esr, struct pt_regs *regs) +{ + int rt = (esr & ESR_ELx_SYS64_ISS_RT_MASK) >> ESR_ELx_SYS64_ISS_RT_SHIFT; + unsigned long val = arm64_ftr_reg_user_value(&arm64_ftr_reg_ctrel0); + + if (cpus_have_const_cap(ARM64_WORKAROUND_1542419)) { + /* Hide DIC so that we can trap the unnecessary maintenance...*/ + val &= ~BIT(CTR_DIC_SHIFT); + + /* ... and fake IminLine to reduce the number of traps. */ + val &= ~CTR_IMINLINE_MASK; + val |= (PAGE_SHIFT - 2) & CTR_IMINLINE_MASK; + } + + pt_regs_write_reg(regs, rt, val); + + arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE); +} + +static void cntvct_read_handler(unsigned int esr, struct pt_regs *regs) +{ + int rt = (esr & ESR_ELx_SYS64_ISS_RT_MASK) >> ESR_ELx_SYS64_ISS_RT_SHIFT; + + pt_regs_write_reg(regs, rt, arch_counter_get_cntvct()); + arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE); +} + +static void cntfrq_read_handler(unsigned int esr, struct pt_regs *regs) +{ + int rt = (esr & ESR_ELx_SYS64_ISS_RT_MASK) >> ESR_ELx_SYS64_ISS_RT_SHIFT; + + pt_regs_write_reg(regs, rt, arch_timer_get_rate()); + arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE); +} + +struct sys64_hook { + unsigned int esr_mask; + unsigned int esr_val; + void (*handler)(unsigned int esr, struct pt_regs *regs); +}; + +static struct sys64_hook sys64_hooks[] = { + { + .esr_mask = ESR_ELx_SYS64_ISS_EL0_CACHE_OP_MASK, + .esr_val = ESR_ELx_SYS64_ISS_EL0_CACHE_OP_VAL, + .handler = user_cache_maint_handler, + }, + { + /* Trap read access to CTR_EL0 */ + .esr_mask = ESR_ELx_SYS64_ISS_SYS_OP_MASK, + .esr_val = ESR_ELx_SYS64_ISS_SYS_CTR_READ, + .handler = ctr_read_handler, + }, + { + /* Trap read access to CNTVCT_EL0 */ + .esr_mask = ESR_ELx_SYS64_ISS_SYS_OP_MASK, + .esr_val = ESR_ELx_SYS64_ISS_SYS_CNTVCT, + .handler = cntvct_read_handler, + }, + { + /* Trap read access to CNTFRQ_EL0 */ + .esr_mask = ESR_ELx_SYS64_ISS_SYS_OP_MASK, + .esr_val = ESR_ELx_SYS64_ISS_SYS_CNTFRQ, + .handler = cntfrq_read_handler, + }, + {}, +}; + +asmlinkage void __exception do_sysinstr(unsigned int esr, struct pt_regs *regs) +{ + struct sys64_hook *hook; + + for (hook = sys64_hooks; hook->handler; hook++) + if ((hook->esr_mask & esr) == hook->esr_val) { + hook->handler(esr, regs); + return; + } + + /* + * New SYS instructions may previously have been undefined at EL0. Fall + * back to our usual undefined instruction handler so that we handle + * these consistently. + */ + do_undefinstr(regs); +} + +static const char *esr_class_str[] = { + [0 ... ESR_ELx_EC_MAX] = "UNRECOGNIZED EC", + [ESR_ELx_EC_UNKNOWN] = "Unknown/Uncategorized", + [ESR_ELx_EC_WFx] = "WFI/WFE", + [ESR_ELx_EC_CP15_32] = "CP15 MCR/MRC", + [ESR_ELx_EC_CP15_64] = "CP15 MCRR/MRRC", + [ESR_ELx_EC_CP14_MR] = "CP14 MCR/MRC", + [ESR_ELx_EC_CP14_LS] = "CP14 LDC/STC", + [ESR_ELx_EC_FP_ASIMD] = "ASIMD", + [ESR_ELx_EC_CP10_ID] = "CP10 MRC/VMRS", + [ESR_ELx_EC_CP14_64] = "CP14 MCRR/MRRC", + [ESR_ELx_EC_ILL] = "PSTATE.IL", + [ESR_ELx_EC_SVC32] = "SVC (AArch32)", + [ESR_ELx_EC_HVC32] = "HVC (AArch32)", + [ESR_ELx_EC_SMC32] = "SMC (AArch32)", + [ESR_ELx_EC_SVC64] = "SVC (AArch64)", + [ESR_ELx_EC_HVC64] = "HVC (AArch64)", + [ESR_ELx_EC_SMC64] = "SMC (AArch64)", + [ESR_ELx_EC_SYS64] = "MSR/MRS (AArch64)", + [ESR_ELx_EC_SVE] = "SVE", + [ESR_ELx_EC_IMP_DEF] = "EL3 IMP DEF", + [ESR_ELx_EC_IABT_LOW] = "IABT (lower EL)", + [ESR_ELx_EC_IABT_CUR] = "IABT (current EL)", + [ESR_ELx_EC_PC_ALIGN] = "PC Alignment", + [ESR_ELx_EC_DABT_LOW] = "DABT (lower EL)", + [ESR_ELx_EC_DABT_CUR] = "DABT (current EL)", + [ESR_ELx_EC_SP_ALIGN] = "SP Alignment", + [ESR_ELx_EC_FP_EXC32] = "FP (AArch32)", + [ESR_ELx_EC_FP_EXC64] = "FP (AArch64)", + [ESR_ELx_EC_SERROR] = "SError", + [ESR_ELx_EC_BREAKPT_LOW] = "Breakpoint (lower EL)", + [ESR_ELx_EC_BREAKPT_CUR] = "Breakpoint (current EL)", + [ESR_ELx_EC_SOFTSTP_LOW] = "Software Step (lower EL)", + [ESR_ELx_EC_SOFTSTP_CUR] = "Software Step (current EL)", + [ESR_ELx_EC_WATCHPT_LOW] = "Watchpoint (lower EL)", + [ESR_ELx_EC_WATCHPT_CUR] = "Watchpoint (current EL)", + [ESR_ELx_EC_BKPT32] = "BKPT (AArch32)", + [ESR_ELx_EC_VECTOR32] = "Vector catch (AArch32)", + [ESR_ELx_EC_BRK64] = "BRK (AArch64)", +}; + +const char *esr_get_class_string(u32 esr) +{ + return esr_class_str[ESR_ELx_EC(esr)]; +} + +/* + * bad_mode handles the impossible case in the exception vector. This is always + * fatal. + */ +asmlinkage void bad_mode(struct pt_regs *regs, int reason, unsigned int esr) +{ + console_verbose(); + + pr_crit("Bad mode in %s handler detected on CPU%d, code 0x%08x -- %s\n", + handler[reason], smp_processor_id(), esr, + esr_get_class_string(esr)); + + local_daif_mask(); + panic("bad mode"); +} + +/* + * bad_el0_sync handles unexpected, but potentially recoverable synchronous + * exceptions taken from EL0. Unlike bad_mode, this returns. + */ +asmlinkage void bad_el0_sync(struct pt_regs *regs, int reason, unsigned int esr) +{ + siginfo_t info; + void __user *pc = (void __user *)instruction_pointer(regs); + + clear_siginfo(&info); + info.si_signo = SIGILL; + info.si_errno = 0; + info.si_code = ILL_ILLOPC; + info.si_addr = pc; + + current->thread.fault_address = 0; + current->thread.fault_code = esr; + + arm64_force_sig_info(&info, "Bad EL0 synchronous exception", current); +} + +#ifdef CONFIG_VMAP_STACK + +DEFINE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)], overflow_stack) + __aligned(16); + +asmlinkage void handle_bad_stack(struct pt_regs *regs) +{ + unsigned long tsk_stk = (unsigned long)current->stack; + unsigned long irq_stk = (unsigned long)this_cpu_read(irq_stack_ptr); + unsigned long ovf_stk = (unsigned long)this_cpu_ptr(overflow_stack); + unsigned int esr = read_sysreg(esr_el1); + unsigned long far = read_sysreg(far_el1); + + console_verbose(); + pr_emerg("Insufficient stack space to handle exception!"); + + pr_emerg("ESR: 0x%08x -- %s\n", esr, esr_get_class_string(esr)); + pr_emerg("FAR: 0x%016lx\n", far); + + pr_emerg("Task stack: [0x%016lx..0x%016lx]\n", + tsk_stk, tsk_stk + THREAD_SIZE); + pr_emerg("IRQ stack: [0x%016lx..0x%016lx]\n", + irq_stk, irq_stk + THREAD_SIZE); + pr_emerg("Overflow stack: [0x%016lx..0x%016lx]\n", + ovf_stk, ovf_stk + OVERFLOW_STACK_SIZE); + + __show_regs(regs); + + /* + * We use nmi_panic to limit the potential for recusive overflows, and + * to get a better stack trace. + */ + nmi_panic(NULL, "kernel stack overflow"); + cpu_park_loop(); +} +#endif + +void __noreturn arm64_serror_panic(struct pt_regs *regs, u32 esr) +{ + console_verbose(); + + pr_crit("SError Interrupt on CPU%d, code 0x%08x -- %s\n", + smp_processor_id(), esr, esr_get_class_string(esr)); + if (regs) + __show_regs(regs); + + nmi_panic(regs, "Asynchronous SError Interrupt"); + + cpu_park_loop(); + unreachable(); +} + +bool arm64_is_fatal_ras_serror(struct pt_regs *regs, unsigned int esr) +{ + u32 aet = arm64_ras_serror_get_severity(esr); + + switch (aet) { + case ESR_ELx_AET_CE: /* corrected error */ + case ESR_ELx_AET_UEO: /* restartable, not yet consumed */ + /* + * The CPU can make progress. We may take UEO again as + * a more severe error. + */ + return false; + + case ESR_ELx_AET_UEU: /* Uncorrected Unrecoverable */ + case ESR_ELx_AET_UER: /* Uncorrected Recoverable */ + /* + * The CPU can't make progress. The exception may have + * been imprecise. + */ + return true; + + case ESR_ELx_AET_UC: /* Uncontainable or Uncategorized error */ + default: + /* Error has been silently propagated */ + arm64_serror_panic(regs, esr); + } +} + +asmlinkage void do_serror(struct pt_regs *regs, unsigned int esr) +{ + nmi_enter(); + + /* non-RAS errors are not containable */ + if (!arm64_is_ras_serror(esr) || arm64_is_fatal_ras_serror(regs, esr)) + arm64_serror_panic(regs, esr); + + nmi_exit(); +} + +void __pte_error(const char *file, int line, unsigned long val) +{ + pr_err("%s:%d: bad pte %016lx.\n", file, line, val); +} + +void __pmd_error(const char *file, int line, unsigned long val) +{ + pr_err("%s:%d: bad pmd %016lx.\n", file, line, val); +} + +void __pud_error(const char *file, int line, unsigned long val) +{ + pr_err("%s:%d: bad pud %016lx.\n", file, line, val); +} + +void __pgd_error(const char *file, int line, unsigned long val) +{ + pr_err("%s:%d: bad pgd %016lx.\n", file, line, val); +} + +/* GENERIC_BUG traps */ + +int is_valid_bugaddr(unsigned long addr) +{ + /* + * bug_handler() only called for BRK #BUG_BRK_IMM. + * So the answer is trivial -- any spurious instances with no + * bug table entry will be rejected by report_bug() and passed + * back to the debug-monitors code and handled as a fatal + * unexpected debug exception. + */ + return 1; +} + +static int bug_handler(struct pt_regs *regs, unsigned int esr) +{ + if (user_mode(regs)) + return DBG_HOOK_ERROR; + + switch (report_bug(regs->pc, regs)) { + case BUG_TRAP_TYPE_BUG: + die("Oops - BUG", regs, 0); + break; + + case BUG_TRAP_TYPE_WARN: + break; + + default: + /* unknown/unrecognised bug trap type */ + return DBG_HOOK_ERROR; + } + + /* If thread survives, skip over the BUG instruction and continue: */ + arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE); + return DBG_HOOK_HANDLED; +} + +static struct break_hook bug_break_hook = { + .esr_val = 0xf2000000 | BUG_BRK_IMM, + .esr_mask = 0xffffffff, + .fn = bug_handler, +}; + +/* + * Initial handler for AArch64 BRK exceptions + * This handler only used until debug_traps_init(). + */ +int __init early_brk64(unsigned long addr, unsigned int esr, + struct pt_regs *regs) +{ + return bug_handler(regs, esr) != DBG_HOOK_HANDLED; +} + +/* This registration must happen early, before debug_traps_init(). */ +void __init trap_init(void) +{ + register_break_hook(&bug_break_hook); +} |