[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>

1 files changed, 22 insertions, 63 deletions

diff --git a/arch/s390/lib/uaccess_pt.c b/arch/s390/lib/uaccess_pt.c
index b159a9d65680..dc37ea827f4e 100644
--- 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;