1062 lines
26 KiB
C
1062 lines
26 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Based on arch/arm/kernel/traps.c
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*
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* Copyright (C) 1995-2009 Russell King
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* Copyright (C) 2012 ARM Ltd.
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*/
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#include <linux/bug.h>
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#include <linux/context_tracking.h>
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#include <linux/signal.h>
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#include <linux/personality.h>
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#include <linux/kallsyms.h>
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#include <linux/kprobes.h>
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#include <linux/spinlock.h>
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#include <linux/uaccess.h>
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#include <linux/hardirq.h>
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#include <linux/kdebug.h>
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#include <linux/module.h>
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#include <linux/kexec.h>
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#include <linux/delay.h>
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#include <linux/init.h>
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#include <linux/sched/signal.h>
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#include <linux/sched/debug.h>
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#include <linux/sched/task_stack.h>
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#include <linux/sizes.h>
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#include <linux/syscalls.h>
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#include <linux/mm_types.h>
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#include <linux/kasan.h>
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#include <asm/atomic.h>
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#include <asm/bug.h>
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#include <asm/cpufeature.h>
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#include <asm/daifflags.h>
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#include <asm/debug-monitors.h>
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#include <asm/esr.h>
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#include <asm/insn.h>
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#include <asm/traps.h>
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#include <asm/smp.h>
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#include <asm/stack_pointer.h>
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#include <asm/stacktrace.h>
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#include <asm/exception.h>
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#include <asm/system_misc.h>
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#include <asm/sysreg.h>
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static const char *handler[]= {
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"Synchronous Abort",
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"IRQ",
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"FIQ",
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"Error"
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};
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int show_unhandled_signals = 0;
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static void dump_backtrace_entry(unsigned long where)
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{
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printk(" %pS\n", (void *)where);
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}
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static void dump_kernel_instr(const char *lvl, struct pt_regs *regs)
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{
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unsigned long addr = instruction_pointer(regs);
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char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str;
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int i;
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if (user_mode(regs))
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return;
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for (i = -4; i < 1; i++) {
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unsigned int val, bad;
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bad = aarch64_insn_read(&((u32 *)addr)[i], &val);
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if (!bad)
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p += sprintf(p, i == 0 ? "(%08x) " : "%08x ", val);
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else {
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p += sprintf(p, "bad PC value");
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break;
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}
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}
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printk("%sCode: %s\n", lvl, str);
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}
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void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
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{
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struct stackframe frame;
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int skip = 0;
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pr_debug("%s(regs = %p tsk = %p)\n", __func__, regs, tsk);
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if (regs) {
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if (user_mode(regs))
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return;
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skip = 1;
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}
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if (!tsk)
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tsk = current;
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if (!try_get_task_stack(tsk))
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return;
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if (tsk == current) {
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start_backtrace(&frame,
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(unsigned long)__builtin_frame_address(0),
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(unsigned long)dump_backtrace);
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} else {
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/*
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* task blocked in __switch_to
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*/
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start_backtrace(&frame,
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thread_saved_fp(tsk),
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thread_saved_pc(tsk));
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}
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printk("Call trace:\n");
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do {
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/* skip until specified stack frame */
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if (!skip) {
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dump_backtrace_entry(frame.pc);
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} else if (frame.fp == regs->regs[29]) {
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skip = 0;
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/*
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* Mostly, this is the case where this function is
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* called in panic/abort. As exception handler's
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* stack frame does not contain the corresponding pc
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* at which an exception has taken place, use regs->pc
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* instead.
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*/
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dump_backtrace_entry(regs->pc);
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}
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} while (!unwind_frame(tsk, &frame));
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put_task_stack(tsk);
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}
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void show_stack(struct task_struct *tsk, unsigned long *sp)
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{
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dump_backtrace(NULL, tsk);
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barrier();
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}
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#ifdef CONFIG_PREEMPT
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#define S_PREEMPT " PREEMPT"
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#else
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#define S_PREEMPT ""
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#endif
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#define S_SMP " SMP"
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static int __die(const char *str, int err, struct pt_regs *regs)
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{
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static int die_counter;
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int ret;
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pr_emerg("Internal error: %s: %x [#%d]" S_PREEMPT S_SMP "\n",
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str, err, ++die_counter);
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/* trap and error numbers are mostly meaningless on ARM */
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ret = notify_die(DIE_OOPS, str, regs, err, 0, SIGSEGV);
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if (ret == NOTIFY_STOP)
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return ret;
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print_modules();
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show_regs(regs);
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dump_kernel_instr(KERN_EMERG, regs);
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return ret;
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}
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static DEFINE_RAW_SPINLOCK(die_lock);
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/*
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* This function is protected against re-entrancy.
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*/
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void die(const char *str, struct pt_regs *regs, int err)
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{
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int ret;
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unsigned long flags;
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raw_spin_lock_irqsave(&die_lock, flags);
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oops_enter();
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console_verbose();
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bust_spinlocks(1);
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ret = __die(str, err, regs);
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if (regs && kexec_should_crash(current))
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crash_kexec(regs);
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bust_spinlocks(0);
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add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
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oops_exit();
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if (in_interrupt())
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panic("Fatal exception in interrupt");
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if (panic_on_oops)
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panic("Fatal exception");
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raw_spin_unlock_irqrestore(&die_lock, flags);
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if (ret != NOTIFY_STOP)
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make_task_dead(SIGSEGV);
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}
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static void arm64_show_signal(int signo, const char *str)
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{
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static DEFINE_RATELIMIT_STATE(rs, DEFAULT_RATELIMIT_INTERVAL,
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DEFAULT_RATELIMIT_BURST);
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struct task_struct *tsk = current;
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unsigned int esr = tsk->thread.fault_code;
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struct pt_regs *regs = task_pt_regs(tsk);
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/* Leave if the signal won't be shown */
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if (!show_unhandled_signals ||
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!unhandled_signal(tsk, signo) ||
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!__ratelimit(&rs))
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return;
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pr_info("%s[%d]: unhandled exception: ", tsk->comm, task_pid_nr(tsk));
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if (esr)
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pr_cont("%s, ESR 0x%08x, ", esr_get_class_string(esr), esr);
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pr_cont("%s", str);
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print_vma_addr(KERN_CONT " in ", regs->pc);
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pr_cont("\n");
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__show_regs(regs);
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}
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void arm64_force_sig_fault(int signo, int code, void __user *addr,
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const char *str)
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{
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arm64_show_signal(signo, str);
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if (signo == SIGKILL)
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force_sig(SIGKILL);
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else
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force_sig_fault(signo, code, addr);
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}
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void arm64_force_sig_mceerr(int code, void __user *addr, short lsb,
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const char *str)
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{
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arm64_show_signal(SIGBUS, str);
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force_sig_mceerr(code, addr, lsb);
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}
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void arm64_force_sig_ptrace_errno_trap(int errno, void __user *addr,
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const char *str)
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{
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arm64_show_signal(SIGTRAP, str);
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force_sig_ptrace_errno_trap(errno, addr);
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}
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void arm64_notify_die(const char *str, struct pt_regs *regs,
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int signo, int sicode, void __user *addr,
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int err)
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{
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if (user_mode(regs)) {
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WARN_ON(regs != current_pt_regs());
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current->thread.fault_address = 0;
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current->thread.fault_code = err;
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arm64_force_sig_fault(signo, sicode, addr, str);
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} else {
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die(str, regs, err);
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}
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}
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void arm64_skip_faulting_instruction(struct pt_regs *regs, unsigned long size)
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{
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regs->pc += size;
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/*
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* If we were single stepping, we want to get the step exception after
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* we return from the trap.
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*/
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if (user_mode(regs))
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user_fastforward_single_step(current);
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}
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static LIST_HEAD(undef_hook);
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static DEFINE_RAW_SPINLOCK(undef_lock);
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void register_undef_hook(struct undef_hook *hook)
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{
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unsigned long flags;
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raw_spin_lock_irqsave(&undef_lock, flags);
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list_add(&hook->node, &undef_hook);
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raw_spin_unlock_irqrestore(&undef_lock, flags);
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}
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void unregister_undef_hook(struct undef_hook *hook)
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{
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unsigned long flags;
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raw_spin_lock_irqsave(&undef_lock, flags);
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list_del(&hook->node);
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raw_spin_unlock_irqrestore(&undef_lock, flags);
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}
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static int call_undef_hook(struct pt_regs *regs)
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{
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struct undef_hook *hook;
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unsigned long flags;
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u32 instr;
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int (*fn)(struct pt_regs *regs, u32 instr) = NULL;
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void __user *pc = (void __user *)instruction_pointer(regs);
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if (!user_mode(regs)) {
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__le32 instr_le;
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if (probe_kernel_address((__force __le32 *)pc, instr_le))
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goto exit;
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instr = le32_to_cpu(instr_le);
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} else if (compat_thumb_mode(regs)) {
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/* 16-bit Thumb instruction */
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__le16 instr_le;
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if (get_user(instr_le, (__le16 __user *)pc))
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goto exit;
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instr = le16_to_cpu(instr_le);
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if (aarch32_insn_is_wide(instr)) {
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u32 instr2;
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if (get_user(instr_le, (__le16 __user *)(pc + 2)))
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goto exit;
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instr2 = le16_to_cpu(instr_le);
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instr = (instr << 16) | instr2;
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}
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} else {
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/* 32-bit ARM instruction */
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__le32 instr_le;
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if (get_user(instr_le, (__le32 __user *)pc))
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goto exit;
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instr = le32_to_cpu(instr_le);
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}
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raw_spin_lock_irqsave(&undef_lock, flags);
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list_for_each_entry(hook, &undef_hook, node)
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if ((instr & hook->instr_mask) == hook->instr_val &&
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(regs->pstate & hook->pstate_mask) == hook->pstate_val)
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fn = hook->fn;
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raw_spin_unlock_irqrestore(&undef_lock, flags);
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exit:
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return fn ? fn(regs, instr) : 1;
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}
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void force_signal_inject(int signal, int code, unsigned long address)
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{
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const char *desc;
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struct pt_regs *regs = current_pt_regs();
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if (WARN_ON(!user_mode(regs)))
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return;
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switch (signal) {
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case SIGILL:
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desc = "undefined instruction";
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break;
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case SIGSEGV:
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desc = "illegal memory access";
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break;
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default:
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desc = "unknown or unrecoverable error";
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break;
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}
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/* Force signals we don't understand to SIGKILL */
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if (WARN_ON(signal != SIGKILL &&
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siginfo_layout(signal, code) != SIL_FAULT)) {
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signal = SIGKILL;
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}
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arm64_notify_die(desc, regs, signal, code, (void __user *)address, 0);
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}
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/*
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* Set up process info to signal segmentation fault - called on access error.
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*/
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void arm64_notify_segfault(unsigned long addr)
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{
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int code;
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down_read(¤t->mm->mmap_sem);
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if (find_vma(current->mm, addr) == NULL)
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code = SEGV_MAPERR;
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else
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code = SEGV_ACCERR;
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up_read(¤t->mm->mmap_sem);
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force_signal_inject(SIGSEGV, code, addr);
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}
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asmlinkage void __exception do_undefinstr(struct pt_regs *regs)
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{
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/* check for AArch32 breakpoint instructions */
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if (!aarch32_break_handler(regs))
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return;
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if (call_undef_hook(regs) == 0)
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return;
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BUG_ON(!user_mode(regs));
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force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc);
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}
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#define __user_cache_maint(insn, address, res) \
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if (address >= user_addr_max()) { \
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res = -EFAULT; \
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} else { \
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uaccess_ttbr0_enable(); \
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asm volatile ( \
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"1: " insn ", %1\n" \
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" mov %w0, #0\n" \
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"2:\n" \
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" .pushsection .fixup,\"ax\"\n" \
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" .align 2\n" \
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"3: mov %w0, %w2\n" \
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" b 2b\n" \
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" .popsection\n" \
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_ASM_EXTABLE(1b, 3b) \
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: "=r" (res) \
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: "r" (address), "i" (-EFAULT)); \
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uaccess_ttbr0_disable(); \
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}
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static void user_cache_maint_handler(unsigned int esr, struct pt_regs *regs)
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{
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unsigned long address;
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int rt = ESR_ELx_SYS64_ISS_RT(esr);
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int crm = (esr & ESR_ELx_SYS64_ISS_CRM_MASK) >> ESR_ELx_SYS64_ISS_CRM_SHIFT;
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int ret = 0;
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address = untagged_addr(pt_regs_read_reg(regs, rt));
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switch (crm) {
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case ESR_ELx_SYS64_ISS_CRM_DC_CVAU: /* DC CVAU, gets promoted */
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__user_cache_maint("dc civac", address, ret);
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break;
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case ESR_ELx_SYS64_ISS_CRM_DC_CVAC: /* DC CVAC, gets promoted */
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__user_cache_maint("dc civac", address, ret);
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break;
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case ESR_ELx_SYS64_ISS_CRM_DC_CVADP: /* DC CVADP */
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__user_cache_maint("sys 3, c7, c13, 1", address, ret);
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break;
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case ESR_ELx_SYS64_ISS_CRM_DC_CVAP: /* DC CVAP */
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__user_cache_maint("sys 3, c7, c12, 1", address, ret);
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break;
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case ESR_ELx_SYS64_ISS_CRM_DC_CIVAC: /* DC CIVAC */
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__user_cache_maint("dc civac", address, ret);
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break;
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case ESR_ELx_SYS64_ISS_CRM_IC_IVAU: /* IC IVAU */
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__user_cache_maint("ic ivau", address, ret);
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break;
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default:
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force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc);
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return;
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}
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if (ret)
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arm64_notify_segfault(address);
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else
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arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE);
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}
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static void ctr_read_handler(unsigned int esr, struct pt_regs *regs)
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{
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int rt = ESR_ELx_SYS64_ISS_RT(esr);
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unsigned long val = arm64_ftr_reg_user_value(&arm64_ftr_reg_ctrel0);
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if (cpus_have_const_cap(ARM64_WORKAROUND_1542419)) {
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/* Hide DIC so that we can trap the unnecessary maintenance...*/
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val &= ~BIT(CTR_DIC_SHIFT);
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/* ... and fake IminLine to reduce the number of traps. */
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val &= ~CTR_IMINLINE_MASK;
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val |= (PAGE_SHIFT - 2) & CTR_IMINLINE_MASK;
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}
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pt_regs_write_reg(regs, rt, val);
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|
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arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE);
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}
|
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|
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static void cntvct_read_handler(unsigned int esr, struct pt_regs *regs)
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{
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int rt = ESR_ELx_SYS64_ISS_RT(esr);
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pt_regs_write_reg(regs, rt, arch_timer_read_counter());
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arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE);
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}
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|
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static void cntfrq_read_handler(unsigned int esr, struct pt_regs *regs)
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{
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int rt = ESR_ELx_SYS64_ISS_RT(esr);
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pt_regs_write_reg(regs, rt, arch_timer_get_rate());
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arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE);
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}
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|
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static void mrs_handler(unsigned int esr, struct pt_regs *regs)
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{
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u32 sysreg, rt;
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|
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rt = ESR_ELx_SYS64_ISS_RT(esr);
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sysreg = esr_sys64_to_sysreg(esr);
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|
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if (do_emulate_mrs(regs, sysreg, rt) != 0)
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force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc);
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}
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|
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static void wfi_handler(unsigned int esr, struct pt_regs *regs)
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{
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arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE);
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}
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|
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struct sys64_hook {
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unsigned int esr_mask;
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unsigned int esr_val;
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void (*handler)(unsigned int esr, struct pt_regs *regs);
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};
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|
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static const 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 CNTVCTSS_EL0 */
|
|
.esr_mask = ESR_ELx_SYS64_ISS_SYS_OP_MASK,
|
|
.esr_val = ESR_ELx_SYS64_ISS_SYS_CNTVCTSS,
|
|
.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,
|
|
},
|
|
{
|
|
/* Trap read access to CPUID registers */
|
|
.esr_mask = ESR_ELx_SYS64_ISS_SYS_MRS_OP_MASK,
|
|
.esr_val = ESR_ELx_SYS64_ISS_SYS_MRS_OP_VAL,
|
|
.handler = mrs_handler,
|
|
},
|
|
{
|
|
/* Trap WFI instructions executed in userspace */
|
|
.esr_mask = ESR_ELx_WFx_MASK,
|
|
.esr_val = ESR_ELx_WFx_WFI_VAL,
|
|
.handler = wfi_handler,
|
|
},
|
|
{},
|
|
};
|
|
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
#define PSTATE_IT_1_0_SHIFT 25
|
|
#define PSTATE_IT_1_0_MASK (0x3 << PSTATE_IT_1_0_SHIFT)
|
|
#define PSTATE_IT_7_2_SHIFT 10
|
|
#define PSTATE_IT_7_2_MASK (0x3f << PSTATE_IT_7_2_SHIFT)
|
|
|
|
static u32 compat_get_it_state(struct pt_regs *regs)
|
|
{
|
|
u32 it, pstate = regs->pstate;
|
|
|
|
it = (pstate & PSTATE_IT_1_0_MASK) >> PSTATE_IT_1_0_SHIFT;
|
|
it |= ((pstate & PSTATE_IT_7_2_MASK) >> PSTATE_IT_7_2_SHIFT) << 2;
|
|
|
|
return it;
|
|
}
|
|
|
|
static void compat_set_it_state(struct pt_regs *regs, u32 it)
|
|
{
|
|
u32 pstate_it;
|
|
|
|
pstate_it = (it << PSTATE_IT_1_0_SHIFT) & PSTATE_IT_1_0_MASK;
|
|
pstate_it |= ((it >> 2) << PSTATE_IT_7_2_SHIFT) & PSTATE_IT_7_2_MASK;
|
|
|
|
regs->pstate &= ~PSR_AA32_IT_MASK;
|
|
regs->pstate |= pstate_it;
|
|
}
|
|
|
|
static bool cp15_cond_valid(unsigned int esr, struct pt_regs *regs)
|
|
{
|
|
int cond;
|
|
|
|
/* Only a T32 instruction can trap without CV being set */
|
|
if (!(esr & ESR_ELx_CV)) {
|
|
u32 it;
|
|
|
|
it = compat_get_it_state(regs);
|
|
if (!it)
|
|
return true;
|
|
|
|
cond = it >> 4;
|
|
} else {
|
|
cond = (esr & ESR_ELx_COND_MASK) >> ESR_ELx_COND_SHIFT;
|
|
}
|
|
|
|
return aarch32_opcode_cond_checks[cond](regs->pstate);
|
|
}
|
|
|
|
static void advance_itstate(struct pt_regs *regs)
|
|
{
|
|
u32 it;
|
|
|
|
/* ARM mode */
|
|
if (!(regs->pstate & PSR_AA32_T_BIT) ||
|
|
!(regs->pstate & PSR_AA32_IT_MASK))
|
|
return;
|
|
|
|
it = compat_get_it_state(regs);
|
|
|
|
/*
|
|
* If this is the last instruction of the block, wipe the IT
|
|
* state. Otherwise advance it.
|
|
*/
|
|
if (!(it & 7))
|
|
it = 0;
|
|
else
|
|
it = (it & 0xe0) | ((it << 1) & 0x1f);
|
|
|
|
compat_set_it_state(regs, it);
|
|
}
|
|
|
|
static void arm64_compat_skip_faulting_instruction(struct pt_regs *regs,
|
|
unsigned int sz)
|
|
{
|
|
advance_itstate(regs);
|
|
arm64_skip_faulting_instruction(regs, sz);
|
|
}
|
|
|
|
static void compat_cntfrq_read_handler(unsigned int esr, struct pt_regs *regs)
|
|
{
|
|
int reg = (esr & ESR_ELx_CP15_32_ISS_RT_MASK) >> ESR_ELx_CP15_32_ISS_RT_SHIFT;
|
|
|
|
pt_regs_write_reg(regs, reg, arch_timer_get_rate());
|
|
arm64_compat_skip_faulting_instruction(regs, 4);
|
|
}
|
|
|
|
static const struct sys64_hook cp15_32_hooks[] = {
|
|
{
|
|
.esr_mask = ESR_ELx_CP15_32_ISS_SYS_MASK,
|
|
.esr_val = ESR_ELx_CP15_32_ISS_SYS_CNTFRQ,
|
|
.handler = compat_cntfrq_read_handler,
|
|
},
|
|
{},
|
|
};
|
|
|
|
static void compat_cntvct_read_handler(unsigned int esr, struct pt_regs *regs)
|
|
{
|
|
int rt = (esr & ESR_ELx_CP15_64_ISS_RT_MASK) >> ESR_ELx_CP15_64_ISS_RT_SHIFT;
|
|
int rt2 = (esr & ESR_ELx_CP15_64_ISS_RT2_MASK) >> ESR_ELx_CP15_64_ISS_RT2_SHIFT;
|
|
u64 val = arch_timer_read_counter();
|
|
|
|
pt_regs_write_reg(regs, rt, lower_32_bits(val));
|
|
pt_regs_write_reg(regs, rt2, upper_32_bits(val));
|
|
arm64_compat_skip_faulting_instruction(regs, 4);
|
|
}
|
|
|
|
static const struct sys64_hook cp15_64_hooks[] = {
|
|
{
|
|
.esr_mask = ESR_ELx_CP15_64_ISS_SYS_MASK,
|
|
.esr_val = ESR_ELx_CP15_64_ISS_SYS_CNTVCT,
|
|
.handler = compat_cntvct_read_handler,
|
|
},
|
|
{
|
|
.esr_mask = ESR_ELx_CP15_64_ISS_SYS_MASK,
|
|
.esr_val = ESR_ELx_CP15_64_ISS_SYS_CNTVCTSS,
|
|
.handler = compat_cntvct_read_handler,
|
|
},
|
|
{},
|
|
};
|
|
|
|
asmlinkage void __exception do_cp15instr(unsigned int esr, struct pt_regs *regs)
|
|
{
|
|
const struct sys64_hook *hook, *hook_base;
|
|
|
|
if (!cp15_cond_valid(esr, regs)) {
|
|
/*
|
|
* There is no T16 variant of a CP access, so we
|
|
* always advance PC by 4 bytes.
|
|
*/
|
|
arm64_compat_skip_faulting_instruction(regs, 4);
|
|
return;
|
|
}
|
|
|
|
switch (ESR_ELx_EC(esr)) {
|
|
case ESR_ELx_EC_CP15_32:
|
|
hook_base = cp15_32_hooks;
|
|
break;
|
|
case ESR_ELx_EC_CP15_64:
|
|
hook_base = cp15_64_hooks;
|
|
break;
|
|
default:
|
|
do_undefinstr(regs);
|
|
return;
|
|
}
|
|
|
|
for (hook = hook_base; hook->handler; hook++)
|
|
if ((hook->esr_mask & esr) == hook->esr_val) {
|
|
hook->handler(esr, regs);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* New cp15 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);
|
|
}
|
|
#endif
|
|
|
|
asmlinkage void __exception do_sysinstr(unsigned int esr, struct pt_regs *regs)
|
|
{
|
|
const 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_PAC] = "PAC",
|
|
[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_ERET] = "ERET/ERETAA/ERETAB",
|
|
[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)
|
|
{
|
|
void __user *pc = (void __user *)instruction_pointer(regs);
|
|
|
|
current->thread.fault_address = 0;
|
|
current->thread.fault_code = esr;
|
|
|
|
arm64_force_sig_fault(SIGILL, ILL_ILLOPC, pc,
|
|
"Bad EL0 synchronous exception");
|
|
}
|
|
|
|
#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.
|
|
*
|
|
* Neoverse-N1 #1349291 means a non-KVM SError reported as
|
|
* Unrecoverable should be treated as Uncontainable. We
|
|
* call arm64_serror_panic() in both cases.
|
|
*/
|
|
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)
|
|
{
|
|
const bool was_in_nmi = in_nmi();
|
|
|
|
if (!was_in_nmi)
|
|
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);
|
|
|
|
if (!was_in_nmi)
|
|
nmi_exit();
|
|
}
|
|
|
|
asmlinkage void enter_from_user_mode(void)
|
|
{
|
|
CT_WARN_ON(ct_state() != CONTEXT_USER);
|
|
user_exit_irqoff();
|
|
}
|
|
NOKPROBE_SYMBOL(enter_from_user_mode);
|
|
|
|
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)
|
|
{
|
|
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 = {
|
|
.fn = bug_handler,
|
|
.imm = BUG_BRK_IMM,
|
|
};
|
|
|
|
#ifdef CONFIG_KASAN_SW_TAGS
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#define KASAN_ESR_RECOVER 0x20
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#define KASAN_ESR_WRITE 0x10
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#define KASAN_ESR_SIZE_MASK 0x0f
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#define KASAN_ESR_SIZE(esr) (1 << ((esr) & KASAN_ESR_SIZE_MASK))
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static int kasan_handler(struct pt_regs *regs, unsigned int esr)
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{
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bool recover = esr & KASAN_ESR_RECOVER;
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bool write = esr & KASAN_ESR_WRITE;
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size_t size = KASAN_ESR_SIZE(esr);
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u64 addr = regs->regs[0];
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u64 pc = regs->pc;
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kasan_report(addr, size, write, pc);
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/*
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* The instrumentation allows to control whether we can proceed after
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* a crash was detected. This is done by passing the -recover flag to
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* the compiler. Disabling recovery allows to generate more compact
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* code.
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*
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* Unfortunately disabling recovery doesn't work for the kernel right
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* now. KASAN reporting is disabled in some contexts (for example when
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* the allocator accesses slab object metadata; this is controlled by
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* current->kasan_depth). All these accesses are detected by the tool,
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* even though the reports for them are not printed.
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*
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* This is something that might be fixed at some point in the future.
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*/
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if (!recover)
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die("Oops - KASAN", regs, 0);
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/* If thread survives, skip over the brk instruction and continue: */
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arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE);
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return DBG_HOOK_HANDLED;
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}
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static struct break_hook kasan_break_hook = {
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.fn = kasan_handler,
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.imm = KASAN_BRK_IMM,
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.mask = KASAN_BRK_MASK,
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};
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#endif
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/*
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* Initial handler for AArch64 BRK exceptions
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* This handler only used until debug_traps_init().
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*/
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int __init early_brk64(unsigned long addr, unsigned int esr,
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struct pt_regs *regs)
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{
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#ifdef CONFIG_KASAN_SW_TAGS
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unsigned int comment = esr & ESR_ELx_BRK64_ISS_COMMENT_MASK;
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if ((comment & ~KASAN_BRK_MASK) == KASAN_BRK_IMM)
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return kasan_handler(regs, esr) != DBG_HOOK_HANDLED;
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#endif
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return bug_handler(regs, esr) != DBG_HOOK_HANDLED;
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}
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/* This registration must happen early, before debug_traps_init(). */
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void __init trap_init(void)
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{
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register_kernel_break_hook(&bug_break_hook);
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#ifdef CONFIG_KASAN_SW_TAGS
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register_kernel_break_hook(&kasan_break_hook);
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#endif
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}
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