]> git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blobdiff - arch/s390/lib/uaccess_pt.c
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux...
[mirror_ubuntu-artful-kernel.git] / arch / s390 / lib / uaccess_pt.c
index 63181671e3e3bfc4ed951dc907ffef1b99d635ae..d66215b0fde9d8d932cd31a43b3dee2e283b3a4a 100644 (file)
 #include <asm/futex.h>
 #include "uaccess.h"
 
+static inline pte_t *follow_table(struct mm_struct *mm, unsigned long addr)
+{
+       pgd_t *pgd;
+       pud_t *pud;
+       pmd_t *pmd;
+
+       pgd = pgd_offset(mm, addr);
+       if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd)))
+               return NULL;
+
+       pud = pud_offset(pgd, addr);
+       if (pud_none(*pud) || unlikely(pud_bad(*pud)))
+               return NULL;
+
+       pmd = pmd_offset(pud, addr);
+       if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd)))
+               return NULL;
+
+       return pte_offset_map(pmd, addr);
+}
+
 static int __handle_fault(struct mm_struct *mm, unsigned long address,
                          int write_access)
 {
        struct vm_area_struct *vma;
        int ret = -EFAULT;
+       int fault;
 
        if (in_atomic())
                return ret;
@@ -44,20 +66,18 @@ static int __handle_fault(struct mm_struct *mm, unsigned long address,
        }
 
 survive:
-       switch (handle_mm_fault(mm, vma, address, write_access)) {
-       case VM_FAULT_MINOR:
-               current->min_flt++;
-               break;
-       case VM_FAULT_MAJOR:
-               current->maj_flt++;
-               break;
-       case VM_FAULT_SIGBUS:
-               goto out_sigbus;
-       case VM_FAULT_OOM:
-               goto out_of_memory;
-       default:
+       fault = handle_mm_fault(mm, vma, address, write_access);
+       if (unlikely(fault & VM_FAULT_ERROR)) {
+               if (fault & VM_FAULT_OOM)
+                       goto out_of_memory;
+               else if (fault & VM_FAULT_SIGBUS)
+                       goto out_sigbus;
                BUG();
        }
+       if (fault & VM_FAULT_MAJOR)
+               current->maj_flt++;
+       else
+               current->min_flt++;
        ret = 0;
 out:
        up_read(&mm->mmap_sem);
@@ -65,7 +85,7 @@ out:
 
 out_of_memory:
        up_read(&mm->mmap_sem);
-       if (is_init(current)) {
+       if (is_global_init(current)) {
                yield();
                down_read(&mm->mmap_sem);
                goto survive;
@@ -86,8 +106,6 @@ static size_t __user_copy_pt(unsigned long uaddr, void *kptr,
 {
        struct mm_struct *mm = current->mm;
        unsigned long offset, pfn, done, size;
-       pgd_t *pgd;
-       pmd_t *pmd;
        pte_t *pte;
        void *from, *to;
 
@@ -95,15 +113,7 @@ static size_t __user_copy_pt(unsigned long uaddr, void *kptr,
 retry:
        spin_lock(&mm->page_table_lock);
        do {
-               pgd = pgd_offset(mm, uaddr);
-               if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd)))
-                       goto fault;
-
-               pmd = pmd_offset(pgd, uaddr);
-               if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd)))
-                       goto fault;
-
-               pte = pte_offset_map(pmd, uaddr);
+               pte = follow_table(mm, uaddr);
                if (!pte || !pte_present(*pte) ||
                    (write_user && !pte_write(*pte)))
                        goto fault;
@@ -143,22 +153,12 @@ static unsigned long __dat_user_addr(unsigned long uaddr)
 {
        struct mm_struct *mm = current->mm;
        unsigned long pfn, ret;
-       pgd_t *pgd;
-       pmd_t *pmd;
        pte_t *pte;
        int rc;
 
        ret = 0;
 retry:
-       pgd = pgd_offset(mm, uaddr);
-       if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd)))
-               goto fault;
-
-       pmd = pmd_offset(pgd, uaddr);
-       if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd)))
-               goto fault;
-
-       pte = pte_offset_map(pmd, uaddr);
+       pte = follow_table(mm, uaddr);
        if (!pte || !pte_present(*pte))
                goto fault;
 
@@ -230,8 +230,6 @@ static size_t strnlen_user_pt(size_t count, const char __user *src)
        unsigned long uaddr = (unsigned long) src;
        struct mm_struct *mm = current->mm;
        unsigned long offset, pfn, done, len;
-       pgd_t *pgd;
-       pmd_t *pmd;
        pte_t *pte;
        size_t len_str;
 
@@ -241,15 +239,7 @@ static size_t strnlen_user_pt(size_t count, const char __user *src)
 retry:
        spin_lock(&mm->page_table_lock);
        do {
-               pgd = pgd_offset(mm, uaddr);
-               if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd)))
-                       goto fault;
-
-               pmd = pmd_offset(pgd, uaddr);
-               if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd)))
-                       goto fault;
-
-               pte = pte_offset_map(pmd, uaddr);
+               pte = follow_table(mm, uaddr);
                if (!pte || !pte_present(*pte))
                        goto fault;
 
@@ -309,48 +299,25 @@ static size_t copy_in_user_pt(size_t n, void __user *to,
                      uaddr, done, size;
        unsigned long uaddr_from = (unsigned long) from;
        unsigned long uaddr_to = (unsigned long) to;
-       pgd_t *pgd_from, *pgd_to;
-       pmd_t *pmd_from, *pmd_to;
        pte_t *pte_from, *pte_to;
        int write_user;
 
+       if (segment_eq(get_fs(), KERNEL_DS)) {
+               memcpy((void __force *) to, (void __force *) from, n);
+               return 0;
+       }
        done = 0;
 retry:
        spin_lock(&mm->page_table_lock);
        do {
-               pgd_from = pgd_offset(mm, uaddr_from);
-               if (pgd_none(*pgd_from) || unlikely(pgd_bad(*pgd_from))) {
-                       uaddr = uaddr_from;
-                       write_user = 0;
-                       goto fault;
-               }
-               pgd_to = pgd_offset(mm, uaddr_to);
-               if (pgd_none(*pgd_to) || unlikely(pgd_bad(*pgd_to))) {
-                       uaddr = uaddr_to;
-                       write_user = 1;
-                       goto fault;
-               }
-
-               pmd_from = pmd_offset(pgd_from, uaddr_from);
-               if (pmd_none(*pmd_from) || unlikely(pmd_bad(*pmd_from))) {
-                       uaddr = uaddr_from;
-                       write_user = 0;
-                       goto fault;
-               }
-               pmd_to = pmd_offset(pgd_to, uaddr_to);
-               if (pmd_none(*pmd_to) || unlikely(pmd_bad(*pmd_to))) {
-                       uaddr = uaddr_to;
-                       write_user = 1;
-                       goto fault;
-               }
-
-               pte_from = pte_offset_map(pmd_from, uaddr_from);
+               pte_from = follow_table(mm, uaddr_from);
                if (!pte_from || !pte_present(*pte_from)) {
                        uaddr = uaddr_from;
                        write_user = 0;
                        goto fault;
                }
-               pte_to = pte_offset_map(pmd_to, uaddr_to);
+
+               pte_to = follow_table(mm, uaddr_to);
                if (!pte_to || !pte_present(*pte_to) || !pte_write(*pte_to)) {
                        uaddr = uaddr_to;
                        write_user = 1;
@@ -398,18 +365,10 @@ fault:
                     : "0" (-EFAULT), "d" (oparg), "a" (uaddr),         \
                       "m" (*uaddr) : "cc" );
 
-int futex_atomic_op_pt(int op, int __user *uaddr, int oparg, int *old)
+static int __futex_atomic_op_pt(int op, int __user *uaddr, int oparg, int *old)
 {
        int oldval = 0, newval, ret;
 
-       spin_lock(&current->mm->page_table_lock);
-       uaddr = (int __user *) __dat_user_addr((unsigned long) uaddr);
-       if (!uaddr) {
-               spin_unlock(&current->mm->page_table_lock);
-               return -EFAULT;
-       }
-       get_page(virt_to_page(uaddr));
-       spin_unlock(&current->mm->page_table_lock);
        switch (op) {
        case FUTEX_OP_SET:
                __futex_atomic_op("lr %2,%5\n",
@@ -434,15 +393,17 @@ int futex_atomic_op_pt(int op, int __user *uaddr, int oparg, int *old)
        default:
                ret = -ENOSYS;
        }
-       put_page(virt_to_page(uaddr));
-       *old = oldval;
+       if (ret == 0)
+               *old = oldval;
        return ret;
 }
 
-int futex_atomic_cmpxchg_pt(int __user *uaddr, int oldval, int newval)
+int futex_atomic_op_pt(int op, int __user *uaddr, int oparg, int *old)
 {
        int ret;
 
+       if (segment_eq(get_fs(), KERNEL_DS))
+               return __futex_atomic_op_pt(op, uaddr, oparg, old);
        spin_lock(&current->mm->page_table_lock);
        uaddr = (int __user *) __dat_user_addr((unsigned long) uaddr);
        if (!uaddr) {
@@ -451,13 +412,40 @@ int futex_atomic_cmpxchg_pt(int __user *uaddr, int oldval, int newval)
        }
        get_page(virt_to_page(uaddr));
        spin_unlock(&current->mm->page_table_lock);
-       asm volatile("   cs   %1,%4,0(%5)\n"
-                    "0: lr   %0,%1\n"
-                    "1:\n"
-                    EX_TABLE(0b,1b)
+       ret = __futex_atomic_op_pt(op, uaddr, oparg, old);
+       put_page(virt_to_page(uaddr));
+       return ret;
+}
+
+static int __futex_atomic_cmpxchg_pt(int __user *uaddr, int oldval, int newval)
+{
+       int ret;
+
+       asm volatile("0: cs   %1,%4,0(%5)\n"
+                    "1: lr   %0,%1\n"
+                    "2:\n"
+                    EX_TABLE(0b,2b) EX_TABLE(1b,2b)
                     : "=d" (ret), "+d" (oldval), "=m" (*uaddr)
                     : "0" (-EFAULT), "d" (newval), "a" (uaddr), "m" (*uaddr)
                     : "cc", "memory" );
+       return ret;
+}
+
+int futex_atomic_cmpxchg_pt(int __user *uaddr, int oldval, int newval)
+{
+       int ret;
+
+       if (segment_eq(get_fs(), KERNEL_DS))
+               return __futex_atomic_cmpxchg_pt(uaddr, oldval, newval);
+       spin_lock(&current->mm->page_table_lock);
+       uaddr = (int __user *) __dat_user_addr((unsigned long) uaddr);
+       if (!uaddr) {
+               spin_unlock(&current->mm->page_table_lock);
+               return -EFAULT;
+       }
+       get_page(virt_to_page(uaddr));
+       spin_unlock(&current->mm->page_table_lock);
+       ret = __futex_atomic_cmpxchg_pt(uaddr, oldval, newval);
        put_page(virt_to_page(uaddr));
        return ret;
 }