[S390] Introduce follow_table in uaccess_pt.c

Define and use follow_table inline in uaccess_pt.c to simplify
the code.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/arch/s390/lib/uaccess_pt.c b/arch/s390/lib/uaccess_pt.c
index b159a9d656807f9283102e5cbeee2d9920ab9b27..dc37ea827f4e329ebb031cab0eae458f38447c73 100644 (file)
--- a/arch/s390/lib/uaccess_pt.c
+++ b/arch/s390/lib/uaccess_pt.c
@@ -15,6 +15,22 @@
 #include <asm/futex.h>
 #include "uaccess.h"
 
+static inline pte_t *follow_table(struct mm_struct *mm, unsigned long addr)
+{
+       pgd_t *pgd;
+       pmd_t *pmd;
+
+       pgd = pgd_offset(mm, addr);
+       if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd)))
+               return NULL;
+
+       pmd = pmd_offset(pgd, 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)
 {
@@ -85,8 +101,6 @@ 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;
 
@@ -94,15 +108,7 @@ 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;
@@ -142,22 +148,12 @@ 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;
 
@@ -229,8 +225,6 @@ 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;
 
@@ -240,15 +234,7 @@ 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;
 
@@ -308,8 +294,6 @@ 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;
 
@@ -317,39 +301,14 @@ static size_t copy_in_user_pt(size_t n, void __user *to,
 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;