Initial commit: OpenHarmony-v4.0-ReleaseOpenHarmony-v4.0-Release

1 files changed, 332 insertions, 0 deletions

diff --git a/arch/mips/mm/fault.c b/arch/mips/mm/fault.c
new file mode 100644
index 000000000..7c871b14e
--- /dev/null
+++ b/arch/mips/mm/fault.c
@@ -0,0 +1,332 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 1995 - 2000 by Ralf Baechle
+ */
+#include <linux/context_tracking.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/ptrace.h>
+#include <linux/ratelimit.h>
+#include <linux/mman.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/kprobes.h>
+#include <linux/perf_event.h>
+#include <linux/uaccess.h>
+
+#include <asm/branch.h>
+#include <asm/mmu_context.h>
+#include <asm/ptrace.h>
+#include <asm/highmem.h>                /* For VMALLOC_END */
+#include <linux/kdebug.h>
+
+int show_unhandled_signals = 1;
+
+/*
+ * This routine handles page faults.  It determines the address,
+ * and the problem, and then passes it off to one of the appropriate
+ * routines.
+ */
+static void __kprobes __do_page_fault(struct pt_regs *regs, unsigned long write,
+        unsigned long address)
+{
+        struct vm_area_struct * vma = NULL;
+        struct task_struct *tsk = current;
+        struct mm_struct *mm = tsk->mm;
+        const int field = sizeof(unsigned long) * 2;
+        int si_code;
+        vm_fault_t fault;
+        unsigned int flags = FAULT_FLAG_DEFAULT;
+
+        static DEFINE_RATELIMIT_STATE(ratelimit_state, 5 * HZ, 10);
+
+#if 0
+        printk("Cpu%d[%s:%d:%0*lx:%ld:%0*lx]\n", raw_smp_processor_id(),
+               current->comm, current->pid, field, address, write,
+               field, regs->cp0_epc);
+#endif
+
+#ifdef CONFIG_KPROBES
+        /*
+         * This is to notify the fault handler of the kprobes.
+         */
+        if (notify_die(DIE_PAGE_FAULT, "page fault", regs, -1,
+                       current->thread.trap_nr, SIGSEGV) == NOTIFY_STOP)
+                return;
+#endif
+
+        si_code = SEGV_MAPERR;
+
+        /*
+         * We fault-in kernel-space virtual memory on-demand. The
+         * 'reference' page table is init_mm.pgd.
+         *
+         * NOTE! We MUST NOT take any locks for this case. We may
+         * be in an interrupt or a critical region, and should
+         * only copy the information from the master page table,
+         * nothing more.
+         */
+#ifdef CONFIG_64BIT
+# define VMALLOC_FAULT_TARGET no_context
+#else
+# define VMALLOC_FAULT_TARGET vmalloc_fault
+#endif
+
+        if (unlikely(address >= VMALLOC_START && address <= VMALLOC_END))
+                goto VMALLOC_FAULT_TARGET;
+#ifdef MODULE_START
+        if (unlikely(address >= MODULE_START && address < MODULE_END))
+                goto VMALLOC_FAULT_TARGET;
+#endif
+
+        /*
+         * If we're in an interrupt or have no user
+         * context, we must not take the fault..
+         */
+        if (faulthandler_disabled() || !mm)
+                goto bad_area_nosemaphore;
+
+        if (user_mode(regs))
+                flags |= FAULT_FLAG_USER;
+
+        perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
+retry:
+        mmap_read_lock(mm);
+        vma = find_vma(mm, address);
+        if (!vma)
+                goto bad_area;
+        if (vma->vm_start <= address)
+                goto good_area;
+        if (!(vma->vm_flags & VM_GROWSDOWN))
+                goto bad_area;
+        if (expand_stack(vma, address))
+                goto bad_area;
+/*
+ * Ok, we have a good vm_area for this memory access, so
+ * we can handle it..
+ */
+good_area:
+        si_code = SEGV_ACCERR;
+
+        if (write) {
+                if (!(vma->vm_flags & VM_WRITE))
+                        goto bad_area;
+                flags |= FAULT_FLAG_WRITE;
+        } else {
+                if (cpu_has_rixi) {
+                        if (address == regs->cp0_epc && !(vma->vm_flags & VM_EXEC)) {
+#if 0
+                                pr_notice("Cpu%d[%s:%d:%0*lx:%ld:%0*lx] XI violation\n",
+                                          raw_smp_processor_id(),
+                                          current->comm, current->pid,
+                                          field, address, write,
+                                          field, regs->cp0_epc);
+#endif
+                                goto bad_area;
+                        }
+                        if (!(vma->vm_flags & VM_READ) &&
+                            exception_epc(regs) != address) {
+#if 0
+                                pr_notice("Cpu%d[%s:%d:%0*lx:%ld:%0*lx] RI violation\n",
+                                          raw_smp_processor_id(),
+                                          current->comm, current->pid,
+                                          field, address, write,
+                                          field, regs->cp0_epc);
+#endif
+                                goto bad_area;
+                        }
+                } else {
+                        if (unlikely(!vma_is_accessible(vma)))
+                                goto bad_area;
+                }
+        }
+
+        /*
+         * If for any reason at all we couldn't handle the fault,
+         * make sure we exit gracefully rather than endlessly redo
+         * the fault.
+         */
+        fault = handle_mm_fault(vma, address, flags, regs);
+
+        if (fault_signal_pending(fault, regs))
+                return;
+
+        if (unlikely(fault & VM_FAULT_ERROR)) {
+                if (fault & VM_FAULT_OOM)
+                        goto out_of_memory;
+                else if (fault & VM_FAULT_SIGSEGV)
+                        goto bad_area;
+                else if (fault & VM_FAULT_SIGBUS)
+                        goto do_sigbus;
+                BUG();
+        }
+        if (flags & FAULT_FLAG_ALLOW_RETRY) {
+                if (fault & VM_FAULT_RETRY) {
+                        flags |= FAULT_FLAG_TRIED;
+
+                        /*
+                         * No need to mmap_read_unlock(mm) as we would
+                         * have already released it in __lock_page_or_retry
+                         * in mm/filemap.c.
+                         */
+
+                        goto retry;
+                }
+        }
+
+        mmap_read_unlock(mm);
+        return;
+
+/*
+ * Something tried to access memory that isn't in our memory map..
+ * Fix it, but check if it's kernel or user first..
+ */
+bad_area:
+        mmap_read_unlock(mm);
+
+bad_area_nosemaphore:
+        /* User mode accesses just cause a SIGSEGV */
+        if (user_mode(regs)) {
+                tsk->thread.cp0_badvaddr = address;
+                tsk->thread.error_code = write;
+                if (show_unhandled_signals &&
+                    unhandled_signal(tsk, SIGSEGV) &&
+                    __ratelimit(&ratelimit_state)) {
+                        pr_info("do_page_fault(): sending SIGSEGV to %s for invalid %s %0*lx\n",
+                                tsk->comm,
+                                write ? "write access to" : "read access from",
+                                field, address);
+                        pr_info("epc = %0*lx in", field,
+                                (unsigned long) regs->cp0_epc);
+                        print_vma_addr(KERN_CONT " ", regs->cp0_epc);
+                        pr_cont("\n");
+                        pr_info("ra  = %0*lx in", field,
+                                (unsigned long) regs->regs[31]);
+                        print_vma_addr(KERN_CONT " ", regs->regs[31]);
+                        pr_cont("\n");
+                }
+                current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;
+                force_sig_fault(SIGSEGV, si_code, (void __user *)address);
+                return;
+        }
+
+no_context:
+        /* Are we prepared to handle this kernel fault?  */
+        if (fixup_exception(regs)) {
+                current->thread.cp0_baduaddr = address;
+                return;
+        }
+
+        /*
+         * Oops. The kernel tried to access some bad page. We'll have to
+         * terminate things with extreme prejudice.
+         */
+        bust_spinlocks(1);
+
+        printk(KERN_ALERT "CPU %d Unable to handle kernel paging request at "
+               "virtual address %0*lx, epc == %0*lx, ra == %0*lx\n",
+               raw_smp_processor_id(), field, address, field, regs->cp0_epc,
+               field,  regs->regs[31]);
+        die("Oops", regs);
+
+out_of_memory:
+        /*
+         * We ran out of memory, call the OOM killer, and return the userspace
+         * (which will retry the fault, or kill us if we got oom-killed).
+         */
+        mmap_read_unlock(mm);
+        if (!user_mode(regs))
+                goto no_context;
+        pagefault_out_of_memory();
+        return;
+
+do_sigbus:
+        mmap_read_unlock(mm);
+
+        /* Kernel mode? Handle exceptions or die */
+        if (!user_mode(regs))
+                goto no_context;
+
+        /*
+         * Send a sigbus, regardless of whether we were in kernel
+         * or user mode.
+         */
+#if 0
+        printk("do_page_fault() #3: sending SIGBUS to %s for "
+               "invalid %s\n%0*lx (epc == %0*lx, ra == %0*lx)\n",
+               tsk->comm,
+               write ? "write access to" : "read access from",
+               field, address,
+               field, (unsigned long) regs->cp0_epc,
+               field, (unsigned long) regs->regs[31]);
+#endif
+        current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;
+        tsk->thread.cp0_badvaddr = address;
+        force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)address);
+
+        return;
+#ifndef CONFIG_64BIT
+vmalloc_fault:
+        {
+                /*
+                 * Synchronize this task's top level page-table
+                 * with the 'reference' page table.
+                 *
+                 * Do _not_ use "tsk" here. We might be inside
+                 * an interrupt in the middle of a task switch..
+                 */
+                int offset = pgd_index(address);
+                pgd_t *pgd, *pgd_k;
+                p4d_t *p4d, *p4d_k;
+                pud_t *pud, *pud_k;
+                pmd_t *pmd, *pmd_k;
+                pte_t *pte_k;
+
+                pgd = (pgd_t *) pgd_current[raw_smp_processor_id()] + offset;
+                pgd_k = init_mm.pgd + offset;
+
+                if (!pgd_present(*pgd_k))
+                        goto no_context;
+                set_pgd(pgd, *pgd_k);
+
+                p4d = p4d_offset(pgd, address);
+                p4d_k = p4d_offset(pgd_k, address);
+                if (!p4d_present(*p4d_k))
+                        goto no_context;
+
+                pud = pud_offset(p4d, address);
+                pud_k = pud_offset(p4d_k, address);
+                if (!pud_present(*pud_k))
+                        goto no_context;
+
+                pmd = pmd_offset(pud, address);
+                pmd_k = pmd_offset(pud_k, address);
+                if (!pmd_present(*pmd_k))
+                        goto no_context;
+                set_pmd(pmd, *pmd_k);
+
+                pte_k = pte_offset_kernel(pmd_k, address);
+                if (!pte_present(*pte_k))
+                        goto no_context;
+                return;
+        }
+#endif
+}
+
+asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
+        unsigned long write, unsigned long address)
+{
+        enum ctx_state prev_state;
+
+        prev_state = exception_enter();
+        __do_page_fault(regs, write, address);
+        exception_exit(prev_state);
+}