v4.19.13 snapshot.
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
new file mode 100644
index 0000000..b9da093
--- /dev/null
+++ b/arch/arm64/kernel/traps.c
@@ -0,0 +1,805 @@
+/*
+ * 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;
+
+ pr_debug("%s(regs = %p tsk = %p)\n", __func__, regs, tsk);
+
+ 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
+
+ skip = !!regs;
+ 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();
+ __show_regs(regs);
+ pr_emerg("Process %.*s (pid: %d, stack limit = 0x%p)\n",
+ TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk),
+ end_of_stack(tsk));
+
+ if (!user_mode(regs)) {
+ dump_backtrace(regs, tsk);
+ 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);
+
+ 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));
+
+ die("Oops - bad mode", regs, 0);
+ 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);
+}