v4.19.13 snapshot.
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
new file mode 100644
index 0000000..50b30ff
--- /dev/null
+++ b/arch/arm64/mm/fault.c
@@ -0,0 +1,880 @@
+/*
+ * Based on arch/arm/mm/fault.c
+ *
+ * Copyright (C) 1995 Linus Torvalds
+ * Copyright (C) 1995-2004 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/extable.h>
+#include <linux/signal.h>
+#include <linux/mm.h>
+#include <linux/hardirq.h>
+#include <linux/init.h>
+#include <linux/kprobes.h>
+#include <linux/uaccess.h>
+#include <linux/page-flags.h>
+#include <linux/sched/signal.h>
+#include <linux/sched/debug.h>
+#include <linux/highmem.h>
+#include <linux/perf_event.h>
+#include <linux/preempt.h>
+#include <linux/hugetlb.h>
+
+#include <asm/bug.h>
+#include <asm/cmpxchg.h>
+#include <asm/cpufeature.h>
+#include <asm/exception.h>
+#include <asm/debug-monitors.h>
+#include <asm/esr.h>
+#include <asm/sysreg.h>
+#include <asm/system_misc.h>
+#include <asm/pgtable.h>
+#include <asm/tlbflush.h>
+#include <asm/traps.h>
+
+#include <acpi/ghes.h>
+
+struct fault_info {
+ int (*fn)(unsigned long addr, unsigned int esr,
+ struct pt_regs *regs);
+ int sig;
+ int code;
+ const char *name;
+};
+
+static const struct fault_info fault_info[];
+
+static inline const struct fault_info *esr_to_fault_info(unsigned int esr)
+{
+ return fault_info + (esr & 63);
+}
+
+#ifdef CONFIG_KPROBES
+static inline int notify_page_fault(struct pt_regs *regs, unsigned int esr)
+{
+ int ret = 0;
+
+ /* kprobe_running() needs smp_processor_id() */
+ if (!user_mode(regs)) {
+ preempt_disable();
+ if (kprobe_running() && kprobe_fault_handler(regs, esr))
+ ret = 1;
+ preempt_enable();
+ }
+
+ return ret;
+}
+#else
+static inline int notify_page_fault(struct pt_regs *regs, unsigned int esr)
+{
+ return 0;
+}
+#endif
+
+static void data_abort_decode(unsigned int esr)
+{
+ pr_alert("Data abort info:\n");
+
+ if (esr & ESR_ELx_ISV) {
+ pr_alert(" Access size = %u byte(s)\n",
+ 1U << ((esr & ESR_ELx_SAS) >> ESR_ELx_SAS_SHIFT));
+ pr_alert(" SSE = %lu, SRT = %lu\n",
+ (esr & ESR_ELx_SSE) >> ESR_ELx_SSE_SHIFT,
+ (esr & ESR_ELx_SRT_MASK) >> ESR_ELx_SRT_SHIFT);
+ pr_alert(" SF = %lu, AR = %lu\n",
+ (esr & ESR_ELx_SF) >> ESR_ELx_SF_SHIFT,
+ (esr & ESR_ELx_AR) >> ESR_ELx_AR_SHIFT);
+ } else {
+ pr_alert(" ISV = 0, ISS = 0x%08lx\n", esr & ESR_ELx_ISS_MASK);
+ }
+
+ pr_alert(" CM = %lu, WnR = %lu\n",
+ (esr & ESR_ELx_CM) >> ESR_ELx_CM_SHIFT,
+ (esr & ESR_ELx_WNR) >> ESR_ELx_WNR_SHIFT);
+}
+
+static void mem_abort_decode(unsigned int esr)
+{
+ pr_alert("Mem abort info:\n");
+
+ pr_alert(" ESR = 0x%08x\n", esr);
+ pr_alert(" Exception class = %s, IL = %u bits\n",
+ esr_get_class_string(esr),
+ (esr & ESR_ELx_IL) ? 32 : 16);
+ pr_alert(" SET = %lu, FnV = %lu\n",
+ (esr & ESR_ELx_SET_MASK) >> ESR_ELx_SET_SHIFT,
+ (esr & ESR_ELx_FnV) >> ESR_ELx_FnV_SHIFT);
+ pr_alert(" EA = %lu, S1PTW = %lu\n",
+ (esr & ESR_ELx_EA) >> ESR_ELx_EA_SHIFT,
+ (esr & ESR_ELx_S1PTW) >> ESR_ELx_S1PTW_SHIFT);
+
+ if (esr_is_data_abort(esr))
+ data_abort_decode(esr);
+}
+
+/*
+ * Dump out the page tables associated with 'addr' in the currently active mm.
+ */
+void show_pte(unsigned long addr)
+{
+ struct mm_struct *mm;
+ pgd_t *pgdp;
+ pgd_t pgd;
+
+ if (addr < TASK_SIZE) {
+ /* TTBR0 */
+ mm = current->active_mm;
+ if (mm == &init_mm) {
+ pr_alert("[%016lx] user address but active_mm is swapper\n",
+ addr);
+ return;
+ }
+ } else if (addr >= VA_START) {
+ /* TTBR1 */
+ mm = &init_mm;
+ } else {
+ pr_alert("[%016lx] address between user and kernel address ranges\n",
+ addr);
+ return;
+ }
+
+ pr_alert("%s pgtable: %luk pages, %u-bit VAs, pgdp = %p\n",
+ mm == &init_mm ? "swapper" : "user", PAGE_SIZE / SZ_1K,
+ VA_BITS, mm->pgd);
+ pgdp = pgd_offset(mm, addr);
+ pgd = READ_ONCE(*pgdp);
+ pr_alert("[%016lx] pgd=%016llx", addr, pgd_val(pgd));
+
+ do {
+ pud_t *pudp, pud;
+ pmd_t *pmdp, pmd;
+ pte_t *ptep, pte;
+
+ if (pgd_none(pgd) || pgd_bad(pgd))
+ break;
+
+ pudp = pud_offset(pgdp, addr);
+ pud = READ_ONCE(*pudp);
+ pr_cont(", pud=%016llx", pud_val(pud));
+ if (pud_none(pud) || pud_bad(pud))
+ break;
+
+ pmdp = pmd_offset(pudp, addr);
+ pmd = READ_ONCE(*pmdp);
+ pr_cont(", pmd=%016llx", pmd_val(pmd));
+ if (pmd_none(pmd) || pmd_bad(pmd))
+ break;
+
+ ptep = pte_offset_map(pmdp, addr);
+ pte = READ_ONCE(*ptep);
+ pr_cont(", pte=%016llx", pte_val(pte));
+ pte_unmap(ptep);
+ } while(0);
+
+ pr_cont("\n");
+}
+
+/*
+ * This function sets the access flags (dirty, accessed), as well as write
+ * permission, and only to a more permissive setting.
+ *
+ * It needs to cope with hardware update of the accessed/dirty state by other
+ * agents in the system and can safely skip the __sync_icache_dcache() call as,
+ * like set_pte_at(), the PTE is never changed from no-exec to exec here.
+ *
+ * Returns whether or not the PTE actually changed.
+ */
+int ptep_set_access_flags(struct vm_area_struct *vma,
+ unsigned long address, pte_t *ptep,
+ pte_t entry, int dirty)
+{
+ pteval_t old_pteval, pteval;
+ pte_t pte = READ_ONCE(*ptep);
+
+ if (pte_same(pte, entry))
+ return 0;
+
+ /* only preserve the access flags and write permission */
+ pte_val(entry) &= PTE_RDONLY | PTE_AF | PTE_WRITE | PTE_DIRTY;
+
+ /*
+ * Setting the flags must be done atomically to avoid racing with the
+ * hardware update of the access/dirty state. The PTE_RDONLY bit must
+ * be set to the most permissive (lowest value) of *ptep and entry
+ * (calculated as: a & b == ~(~a | ~b)).
+ */
+ pte_val(entry) ^= PTE_RDONLY;
+ pteval = pte_val(pte);
+ do {
+ old_pteval = pteval;
+ pteval ^= PTE_RDONLY;
+ pteval |= pte_val(entry);
+ pteval ^= PTE_RDONLY;
+ pteval = cmpxchg_relaxed(&pte_val(*ptep), old_pteval, pteval);
+ } while (pteval != old_pteval);
+
+ flush_tlb_fix_spurious_fault(vma, address);
+ return 1;
+}
+
+static bool is_el1_instruction_abort(unsigned int esr)
+{
+ return ESR_ELx_EC(esr) == ESR_ELx_EC_IABT_CUR;
+}
+
+static inline bool is_el1_permission_fault(unsigned int esr,
+ struct pt_regs *regs,
+ unsigned long addr)
+{
+ unsigned int ec = ESR_ELx_EC(esr);
+ unsigned int fsc_type = esr & ESR_ELx_FSC_TYPE;
+
+ if (ec != ESR_ELx_EC_DABT_CUR && ec != ESR_ELx_EC_IABT_CUR)
+ return false;
+
+ if (fsc_type == ESR_ELx_FSC_PERM)
+ return true;
+
+ if (addr < TASK_SIZE && system_uses_ttbr0_pan())
+ return fsc_type == ESR_ELx_FSC_FAULT &&
+ (regs->pstate & PSR_PAN_BIT);
+
+ return false;
+}
+
+static void die_kernel_fault(const char *msg, unsigned long addr,
+ unsigned int esr, struct pt_regs *regs)
+{
+ bust_spinlocks(1);
+
+ pr_alert("Unable to handle kernel %s at virtual address %016lx\n", msg,
+ addr);
+
+ mem_abort_decode(esr);
+
+ show_pte(addr);
+ die("Oops", regs, esr);
+ bust_spinlocks(0);
+ do_exit(SIGKILL);
+}
+
+static void __do_kernel_fault(unsigned long addr, unsigned int esr,
+ struct pt_regs *regs)
+{
+ const char *msg;
+
+ /*
+ * Are we prepared to handle this kernel fault?
+ * We are almost certainly not prepared to handle instruction faults.
+ */
+ if (!is_el1_instruction_abort(esr) && fixup_exception(regs))
+ return;
+
+ if (is_el1_permission_fault(esr, regs, addr)) {
+ if (esr & ESR_ELx_WNR)
+ msg = "write to read-only memory";
+ else
+ msg = "read from unreadable memory";
+ } else if (addr < PAGE_SIZE) {
+ msg = "NULL pointer dereference";
+ } else {
+ msg = "paging request";
+ }
+
+ die_kernel_fault(msg, addr, esr, regs);
+}
+
+static void __do_user_fault(struct siginfo *info, unsigned int esr)
+{
+ current->thread.fault_address = (unsigned long)info->si_addr;
+
+ /*
+ * If the faulting address is in the kernel, we must sanitize the ESR.
+ * From userspace's point of view, kernel-only mappings don't exist
+ * at all, so we report them as level 0 translation faults.
+ * (This is not quite the way that "no mapping there at all" behaves:
+ * an alignment fault not caused by the memory type would take
+ * precedence over translation fault for a real access to empty
+ * space. Unfortunately we can't easily distinguish "alignment fault
+ * not caused by memory type" from "alignment fault caused by memory
+ * type", so we ignore this wrinkle and just return the translation
+ * fault.)
+ */
+ if (current->thread.fault_address >= TASK_SIZE) {
+ switch (ESR_ELx_EC(esr)) {
+ case ESR_ELx_EC_DABT_LOW:
+ /*
+ * These bits provide only information about the
+ * faulting instruction, which userspace knows already.
+ * We explicitly clear bits which are architecturally
+ * RES0 in case they are given meanings in future.
+ * We always report the ESR as if the fault was taken
+ * to EL1 and so ISV and the bits in ISS[23:14] are
+ * clear. (In fact it always will be a fault to EL1.)
+ */
+ esr &= ESR_ELx_EC_MASK | ESR_ELx_IL |
+ ESR_ELx_CM | ESR_ELx_WNR;
+ esr |= ESR_ELx_FSC_FAULT;
+ break;
+ case ESR_ELx_EC_IABT_LOW:
+ /*
+ * Claim a level 0 translation fault.
+ * All other bits are architecturally RES0 for faults
+ * reported with that DFSC value, so we clear them.
+ */
+ esr &= ESR_ELx_EC_MASK | ESR_ELx_IL;
+ esr |= ESR_ELx_FSC_FAULT;
+ break;
+ default:
+ /*
+ * This should never happen (entry.S only brings us
+ * into this code for insn and data aborts from a lower
+ * exception level). Fail safe by not providing an ESR
+ * context record at all.
+ */
+ WARN(1, "ESR 0x%x is not DABT or IABT from EL0\n", esr);
+ esr = 0;
+ break;
+ }
+ }
+
+ current->thread.fault_code = esr;
+ arm64_force_sig_info(info, esr_to_fault_info(esr)->name, current);
+}
+
+static void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *regs)
+{
+ /*
+ * If we are in kernel mode at this point, we have no context to
+ * handle this fault with.
+ */
+ if (user_mode(regs)) {
+ const struct fault_info *inf = esr_to_fault_info(esr);
+ struct siginfo si;
+
+ clear_siginfo(&si);
+ si.si_signo = inf->sig;
+ si.si_code = inf->code;
+ si.si_addr = (void __user *)addr;
+
+ __do_user_fault(&si, esr);
+ } else {
+ __do_kernel_fault(addr, esr, regs);
+ }
+}
+
+#define VM_FAULT_BADMAP 0x010000
+#define VM_FAULT_BADACCESS 0x020000
+
+static vm_fault_t __do_page_fault(struct mm_struct *mm, unsigned long addr,
+ unsigned int mm_flags, unsigned long vm_flags,
+ struct task_struct *tsk)
+{
+ struct vm_area_struct *vma;
+ vm_fault_t fault;
+
+ vma = find_vma(mm, addr);
+ fault = VM_FAULT_BADMAP;
+ if (unlikely(!vma))
+ goto out;
+ if (unlikely(vma->vm_start > addr))
+ goto check_stack;
+
+ /*
+ * Ok, we have a good vm_area for this memory access, so we can handle
+ * it.
+ */
+good_area:
+ /*
+ * Check that the permissions on the VMA allow for the fault which
+ * occurred.
+ */
+ if (!(vma->vm_flags & vm_flags)) {
+ fault = VM_FAULT_BADACCESS;
+ goto out;
+ }
+
+ return handle_mm_fault(vma, addr & PAGE_MASK, mm_flags);
+
+check_stack:
+ if (vma->vm_flags & VM_GROWSDOWN && !expand_stack(vma, addr))
+ goto good_area;
+out:
+ return fault;
+}
+
+static bool is_el0_instruction_abort(unsigned int esr)
+{
+ return ESR_ELx_EC(esr) == ESR_ELx_EC_IABT_LOW;
+}
+
+static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
+ struct pt_regs *regs)
+{
+ struct task_struct *tsk;
+ struct mm_struct *mm;
+ struct siginfo si;
+ vm_fault_t fault, major = 0;
+ unsigned long vm_flags = VM_READ | VM_WRITE;
+ unsigned int mm_flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
+
+ if (notify_page_fault(regs, esr))
+ return 0;
+
+ tsk = current;
+ mm = tsk->mm;
+
+ /*
+ * If we're in an interrupt or have no user context, we must not take
+ * the fault.
+ */
+ if (faulthandler_disabled() || !mm)
+ goto no_context;
+
+ if (user_mode(regs))
+ mm_flags |= FAULT_FLAG_USER;
+
+ if (is_el0_instruction_abort(esr)) {
+ vm_flags = VM_EXEC;
+ } else if ((esr & ESR_ELx_WNR) && !(esr & ESR_ELx_CM)) {
+ vm_flags = VM_WRITE;
+ mm_flags |= FAULT_FLAG_WRITE;
+ }
+
+ if (addr < TASK_SIZE && is_el1_permission_fault(esr, regs, addr)) {
+ /* regs->orig_addr_limit may be 0 if we entered from EL0 */
+ if (regs->orig_addr_limit == KERNEL_DS)
+ die_kernel_fault("access to user memory with fs=KERNEL_DS",
+ addr, esr, regs);
+
+ if (is_el1_instruction_abort(esr))
+ die_kernel_fault("execution of user memory",
+ addr, esr, regs);
+
+ if (!search_exception_tables(regs->pc))
+ die_kernel_fault("access to user memory outside uaccess routines",
+ addr, esr, regs);
+ }
+
+ perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr);
+
+ /*
+ * As per x86, we may deadlock here. However, since the kernel only
+ * validly references user space from well defined areas of the code,
+ * we can bug out early if this is from code which shouldn't.
+ */
+ if (!down_read_trylock(&mm->mmap_sem)) {
+ if (!user_mode(regs) && !search_exception_tables(regs->pc))
+ goto no_context;
+retry:
+ down_read(&mm->mmap_sem);
+ } else {
+ /*
+ * The above down_read_trylock() might have succeeded in which
+ * case, we'll have missed the might_sleep() from down_read().
+ */
+ might_sleep();
+#ifdef CONFIG_DEBUG_VM
+ if (!user_mode(regs) && !search_exception_tables(regs->pc))
+ goto no_context;
+#endif
+ }
+
+ fault = __do_page_fault(mm, addr, mm_flags, vm_flags, tsk);
+ major |= fault & VM_FAULT_MAJOR;
+
+ if (fault & VM_FAULT_RETRY) {
+ /*
+ * If we need to retry but a fatal signal is pending,
+ * handle the signal first. We do not need to release
+ * the mmap_sem because it would already be released
+ * in __lock_page_or_retry in mm/filemap.c.
+ */
+ if (fatal_signal_pending(current)) {
+ if (!user_mode(regs))
+ goto no_context;
+ return 0;
+ }
+
+ /*
+ * Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk of
+ * starvation.
+ */
+ if (mm_flags & FAULT_FLAG_ALLOW_RETRY) {
+ mm_flags &= ~FAULT_FLAG_ALLOW_RETRY;
+ mm_flags |= FAULT_FLAG_TRIED;
+ goto retry;
+ }
+ }
+ up_read(&mm->mmap_sem);
+
+ /*
+ * Handle the "normal" (no error) case first.
+ */
+ if (likely(!(fault & (VM_FAULT_ERROR | VM_FAULT_BADMAP |
+ VM_FAULT_BADACCESS)))) {
+ /*
+ * Major/minor page fault accounting is only done
+ * once. If we go through a retry, it is extremely
+ * likely that the page will be found in page cache at
+ * that point.
+ */
+ if (major) {
+ tsk->maj_flt++;
+ perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, regs,
+ addr);
+ } else {
+ tsk->min_flt++;
+ perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, regs,
+ addr);
+ }
+
+ return 0;
+ }
+
+ /*
+ * If we are in kernel mode at this point, we have no context to
+ * handle this fault with.
+ */
+ if (!user_mode(regs))
+ goto no_context;
+
+ if (fault & VM_FAULT_OOM) {
+ /*
+ * We ran out of memory, call the OOM killer, and return to
+ * userspace (which will retry the fault, or kill us if we got
+ * oom-killed).
+ */
+ pagefault_out_of_memory();
+ return 0;
+ }
+
+ clear_siginfo(&si);
+ si.si_addr = (void __user *)addr;
+
+ if (fault & VM_FAULT_SIGBUS) {
+ /*
+ * We had some memory, but were unable to successfully fix up
+ * this page fault.
+ */
+ si.si_signo = SIGBUS;
+ si.si_code = BUS_ADRERR;
+ } else if (fault & VM_FAULT_HWPOISON_LARGE) {
+ unsigned int hindex = VM_FAULT_GET_HINDEX(fault);
+
+ si.si_signo = SIGBUS;
+ si.si_code = BUS_MCEERR_AR;
+ si.si_addr_lsb = hstate_index_to_shift(hindex);
+ } else if (fault & VM_FAULT_HWPOISON) {
+ si.si_signo = SIGBUS;
+ si.si_code = BUS_MCEERR_AR;
+ si.si_addr_lsb = PAGE_SHIFT;
+ } else {
+ /*
+ * Something tried to access memory that isn't in our memory
+ * map.
+ */
+ si.si_signo = SIGSEGV;
+ si.si_code = fault == VM_FAULT_BADACCESS ?
+ SEGV_ACCERR : SEGV_MAPERR;
+ }
+
+ __do_user_fault(&si, esr);
+ return 0;
+
+no_context:
+ __do_kernel_fault(addr, esr, regs);
+ return 0;
+}
+
+static int __kprobes do_translation_fault(unsigned long addr,
+ unsigned int esr,
+ struct pt_regs *regs)
+{
+ if (addr < TASK_SIZE)
+ return do_page_fault(addr, esr, regs);
+
+ do_bad_area(addr, esr, regs);
+ return 0;
+}
+
+static int do_alignment_fault(unsigned long addr, unsigned int esr,
+ struct pt_regs *regs)
+{
+ do_bad_area(addr, esr, regs);
+ return 0;
+}
+
+static int do_bad(unsigned long addr, unsigned int esr, struct pt_regs *regs)
+{
+ return 1; /* "fault" */
+}
+
+static int do_sea(unsigned long addr, unsigned int esr, struct pt_regs *regs)
+{
+ struct siginfo info;
+ const struct fault_info *inf;
+
+ inf = esr_to_fault_info(esr);
+
+ /*
+ * Synchronous aborts may interrupt code which had interrupts masked.
+ * Before calling out into the wider kernel tell the interested
+ * subsystems.
+ */
+ if (IS_ENABLED(CONFIG_ACPI_APEI_SEA)) {
+ if (interrupts_enabled(regs))
+ nmi_enter();
+
+ ghes_notify_sea();
+
+ if (interrupts_enabled(regs))
+ nmi_exit();
+ }
+
+ clear_siginfo(&info);
+ info.si_signo = inf->sig;
+ info.si_errno = 0;
+ info.si_code = inf->code;
+ if (esr & ESR_ELx_FnV)
+ info.si_addr = NULL;
+ else
+ info.si_addr = (void __user *)addr;
+ arm64_notify_die(inf->name, regs, &info, esr);
+
+ return 0;
+}
+
+static const struct fault_info fault_info[] = {
+ { do_bad, SIGKILL, SI_KERNEL, "ttbr address size fault" },
+ { do_bad, SIGKILL, SI_KERNEL, "level 1 address size fault" },
+ { do_bad, SIGKILL, SI_KERNEL, "level 2 address size fault" },
+ { do_bad, SIGKILL, SI_KERNEL, "level 3 address size fault" },
+ { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 0 translation fault" },
+ { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 1 translation fault" },
+ { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 2 translation fault" },
+ { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 3 translation fault" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 8" },
+ { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 access flag fault" },
+ { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 access flag fault" },
+ { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 access flag fault" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 12" },
+ { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 permission fault" },
+ { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 permission fault" },
+ { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 permission fault" },
+ { do_sea, SIGBUS, BUS_OBJERR, "synchronous external abort" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 17" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 18" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 19" },
+ { do_sea, SIGKILL, SI_KERNEL, "level 0 (translation table walk)" },
+ { do_sea, SIGKILL, SI_KERNEL, "level 1 (translation table walk)" },
+ { do_sea, SIGKILL, SI_KERNEL, "level 2 (translation table walk)" },
+ { do_sea, SIGKILL, SI_KERNEL, "level 3 (translation table walk)" },
+ { do_sea, SIGBUS, BUS_OBJERR, "synchronous parity or ECC error" }, // Reserved when RAS is implemented
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 25" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 26" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 27" },
+ { do_sea, SIGKILL, SI_KERNEL, "level 0 synchronous parity error (translation table walk)" }, // Reserved when RAS is implemented
+ { do_sea, SIGKILL, SI_KERNEL, "level 1 synchronous parity error (translation table walk)" }, // Reserved when RAS is implemented
+ { do_sea, SIGKILL, SI_KERNEL, "level 2 synchronous parity error (translation table walk)" }, // Reserved when RAS is implemented
+ { do_sea, SIGKILL, SI_KERNEL, "level 3 synchronous parity error (translation table walk)" }, // Reserved when RAS is implemented
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 32" },
+ { do_alignment_fault, SIGBUS, BUS_ADRALN, "alignment fault" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 34" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 35" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 36" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 37" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 38" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 39" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 40" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 41" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 42" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 43" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 44" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 45" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 46" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 47" },
+ { do_bad, SIGKILL, SI_KERNEL, "TLB conflict abort" },
+ { do_bad, SIGKILL, SI_KERNEL, "Unsupported atomic hardware update fault" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 50" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 51" },
+ { do_bad, SIGKILL, SI_KERNEL, "implementation fault (lockdown abort)" },
+ { do_bad, SIGBUS, BUS_OBJERR, "implementation fault (unsupported exclusive)" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 54" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 55" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 56" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 57" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 58" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 59" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 60" },
+ { do_bad, SIGKILL, SI_KERNEL, "section domain fault" },
+ { do_bad, SIGKILL, SI_KERNEL, "page domain fault" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 63" },
+};
+
+int handle_guest_sea(phys_addr_t addr, unsigned int esr)
+{
+ return ghes_notify_sea();
+}
+
+asmlinkage void __exception do_mem_abort(unsigned long addr, unsigned int esr,
+ struct pt_regs *regs)
+{
+ const struct fault_info *inf = esr_to_fault_info(esr);
+ struct siginfo info;
+
+ if (!inf->fn(addr, esr, regs))
+ return;
+
+ if (!user_mode(regs)) {
+ pr_alert("Unhandled fault at 0x%016lx\n", addr);
+ mem_abort_decode(esr);
+ show_pte(addr);
+ }
+
+ clear_siginfo(&info);
+ info.si_signo = inf->sig;
+ info.si_errno = 0;
+ info.si_code = inf->code;
+ info.si_addr = (void __user *)addr;
+ arm64_notify_die(inf->name, regs, &info, esr);
+}
+
+asmlinkage void __exception do_el0_irq_bp_hardening(void)
+{
+ /* PC has already been checked in entry.S */
+ arm64_apply_bp_hardening();
+}
+
+asmlinkage void __exception do_el0_ia_bp_hardening(unsigned long addr,
+ unsigned int esr,
+ struct pt_regs *regs)
+{
+ /*
+ * We've taken an instruction abort from userspace and not yet
+ * re-enabled IRQs. If the address is a kernel address, apply
+ * BP hardening prior to enabling IRQs and pre-emption.
+ */
+ if (addr > TASK_SIZE)
+ arm64_apply_bp_hardening();
+
+ local_irq_enable();
+ do_mem_abort(addr, esr, regs);
+}
+
+
+asmlinkage void __exception do_sp_pc_abort(unsigned long addr,
+ unsigned int esr,
+ struct pt_regs *regs)
+{
+ struct siginfo info;
+
+ if (user_mode(regs)) {
+ if (instruction_pointer(regs) > TASK_SIZE)
+ arm64_apply_bp_hardening();
+ local_irq_enable();
+ }
+
+ clear_siginfo(&info);
+ info.si_signo = SIGBUS;
+ info.si_errno = 0;
+ info.si_code = BUS_ADRALN;
+ info.si_addr = (void __user *)addr;
+ arm64_notify_die("SP/PC alignment exception", regs, &info, esr);
+}
+
+int __init early_brk64(unsigned long addr, unsigned int esr,
+ struct pt_regs *regs);
+
+/*
+ * __refdata because early_brk64 is __init, but the reference to it is
+ * clobbered at arch_initcall time.
+ * See traps.c and debug-monitors.c:debug_traps_init().
+ */
+static struct fault_info __refdata debug_fault_info[] = {
+ { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware breakpoint" },
+ { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware single-step" },
+ { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware watchpoint" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 3" },
+ { do_bad, SIGTRAP, TRAP_BRKPT, "aarch32 BKPT" },
+ { do_bad, SIGKILL, SI_KERNEL, "aarch32 vector catch" },
+ { early_brk64, SIGTRAP, TRAP_BRKPT, "aarch64 BRK" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 7" },
+};
+
+void __init hook_debug_fault_code(int nr,
+ int (*fn)(unsigned long, unsigned int, struct pt_regs *),
+ int sig, int code, const char *name)
+{
+ BUG_ON(nr < 0 || nr >= ARRAY_SIZE(debug_fault_info));
+
+ debug_fault_info[nr].fn = fn;
+ debug_fault_info[nr].sig = sig;
+ debug_fault_info[nr].code = code;
+ debug_fault_info[nr].name = name;
+}
+
+asmlinkage int __exception do_debug_exception(unsigned long addr,
+ unsigned int esr,
+ struct pt_regs *regs)
+{
+ const struct fault_info *inf = debug_fault_info + DBG_ESR_EVT(esr);
+ int rv;
+
+ /*
+ * Tell lockdep we disabled irqs in entry.S. Do nothing if they were
+ * already disabled to preserve the last enabled/disabled addresses.
+ */
+ if (interrupts_enabled(regs))
+ trace_hardirqs_off();
+
+ if (user_mode(regs) && instruction_pointer(regs) > TASK_SIZE)
+ arm64_apply_bp_hardening();
+
+ if (!inf->fn(addr, esr, regs)) {
+ rv = 1;
+ } else {
+ struct siginfo info;
+
+ clear_siginfo(&info);
+ info.si_signo = inf->sig;
+ info.si_errno = 0;
+ info.si_code = inf->code;
+ info.si_addr = (void __user *)addr;
+ arm64_notify_die(inf->name, regs, &info, esr);
+ rv = 0;
+ }
+
+ if (interrupts_enabled(regs))
+ trace_hardirqs_on();
+
+ return rv;
+}
+NOKPROBE_SYMBOL(do_debug_exception);
+
+#ifdef CONFIG_ARM64_PAN
+void cpu_enable_pan(const struct arm64_cpu_capabilities *__unused)
+{
+ /*
+ * We modify PSTATE. This won't work from irq context as the PSTATE
+ * is discarded once we return from the exception.
+ */
+ WARN_ON_ONCE(in_interrupt());
+
+ sysreg_clear_set(sctlr_el1, SCTLR_EL1_SPAN, 0);
+ asm(SET_PSTATE_PAN(1));
+}
+#endif /* CONFIG_ARM64_PAN */