1 files changed, 71 insertions, 69 deletions

diff --git a/arch/um/kernel/skas/uaccess.c b/arch/um/kernel/skas/uaccess.c
index 1d8b119f2d0e..e22c96993db3 100644
--- a/arch/um/kernel/skas/uaccess.c
+++ b/arch/um/kernel/skas/uaccess.c
@@ -3,128 +3,130 @@
  * Licensed under the GPL
  */
 
-#include "linux/err.h"
-#include "linux/highmem.h"
-#include "linux/mm.h"
-#include "asm/current.h"
-#include "asm/page.h"
-#include "asm/pgtable.h"
+#include <linux/err.h>
+#include <linux/highmem.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <asm/current.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
 #include "kern_util.h"
 #include "os.h"
 
-extern void *um_virt_to_phys(struct task_struct *task, unsigned long addr,
-                             pte_t *pte_out);
-
-static unsigned long maybe_map(unsigned long virt, int is_write)
+pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr)
 {
-        pte_t pte;
-        int err;
+        pgd_t *pgd;
+        pud_t *pud;
+        pmd_t *pmd;
+
+        if (mm == NULL)
+                return NULL;
+
+        pgd = pgd_offset(mm, addr);
+        if (!pgd_present(*pgd))
+                return NULL;
+
+        pud = pud_offset(pgd, addr);
+        if (!pud_present(*pud))
+                return NULL;
 
-        void *phys = um_virt_to_phys(current, virt, &pte);
-        int dummy_code;
+        pmd = pmd_offset(pud, addr);
+        if (!pmd_present(*pmd))
+                return NULL;
+
+        return pte_offset_kernel(pmd, addr);
+}
+
+static pte_t *maybe_map(unsigned long virt, int is_write)
+{
+        pte_t *pte = virt_to_pte(current->mm, virt);
+        int err, dummy_code;
 
-        if (IS_ERR(phys) || (is_write && !pte_write(pte))) {
+        if ((pte == NULL) || !pte_present(*pte) ||
+            (is_write && !pte_write(*pte))) {
                 err = handle_page_fault(virt, 0, is_write, 1, &dummy_code);
                 if (err)
-                        return -1UL;
-                phys = um_virt_to_phys(current, virt, NULL);
+                        return NULL;
+                pte = virt_to_pte(current->mm, virt);
         }
-        if (IS_ERR(phys))
-                phys = (void *) -1;
+        if (!pte_present(*pte))
+                pte = NULL;
 
-        return (unsigned long) phys;
+        return pte;
 }
 
 static int do_op_one_page(unsigned long addr, int len, int is_write,
                  int (*op)(unsigned long addr, int len, void *arg), void *arg)
 {
+        jmp_buf buf;
         struct page *page;
-        int n;
+        pte_t *pte;
+        int n, faulted;
 
-        addr = maybe_map(addr, is_write);
-        if (addr == -1UL)
+        pte = maybe_map(addr, is_write);
+        if (pte == NULL)
                 return -1;
 
-        page = phys_to_page(addr);
+        page = pte_page(*pte);
         addr = (unsigned long) kmap_atomic(page, KM_UML_USERCOPY) +
                 (addr & ~PAGE_MASK);
 
-        n = (*op)(addr, len, arg);
+        current->thread.fault_catcher = &buf;
+
+        faulted = UML_SETJMP(&buf);
+        if (faulted == 0)
+                n = (*op)(addr, len, arg);
+        else
+                n = -1;
+
+        current->thread.fault_catcher = NULL;
 
         kunmap_atomic(page, KM_UML_USERCOPY);
 
         return n;
 }
 
-static void do_buffer_op(void *jmpbuf, void *arg_ptr)
+static int buffer_op(unsigned long addr, int len, int is_write,
+                     int (*op)(unsigned long, int, void *), void *arg)
 {
-        va_list args;
-        unsigned long addr;
-        int len, is_write, size, remain, n;
-        int (*op)(unsigned long, int, void *);
-        void *arg;
-        int *res;
-
-        va_copy(args, *(va_list *)arg_ptr);
-        addr = va_arg(args, unsigned long);
-        len = va_arg(args, int);
-        is_write = va_arg(args, int);
-        op = va_arg(args, void *);
-        arg = va_arg(args, void *);
-        res = va_arg(args, int *);
-        va_end(args);
+        int size, remain, n;
+
         size = min(PAGE_ALIGN(addr) - addr, (unsigned long) len);
         remain = len;
 
-        current->thread.fault_catcher = jmpbuf;
         n = do_op_one_page(addr, size, is_write, op, arg);
         if (n != 0) {
-                *res = (n < 0 ? remain : 0);
+                remain = (n < 0 ? remain : 0);
                 goto out;
         }
 
         addr += size;
         remain -= size;
-        if (remain == 0) {
-                *res = 0;
+        if (remain == 0)
                 goto out;
-        }
 
-        while(addr < ((addr + remain) & PAGE_MASK)) {
+        while (addr < ((addr + remain) & PAGE_MASK)) {
                 n = do_op_one_page(addr, PAGE_SIZE, is_write, op, arg);
                 if (n != 0) {
-                        *res = (n < 0 ? remain : 0);
+                        remain = (n < 0 ? remain : 0);
                         goto out;
                 }
 
                 addr += PAGE_SIZE;
                 remain -= PAGE_SIZE;
         }
-        if (remain == 0) {
-                *res = 0;
+        if (remain == 0)
                 goto out;
-        }
 
         n = do_op_one_page(addr, remain, is_write, op, arg);
-        if (n != 0)
-                *res = (n < 0 ? remain : 0);
-        else *res = 0;
- out:
-        current->thread.fault_catcher = NULL;
-}
-
-static int buffer_op(unsigned long addr, int len, int is_write,
-                     int (*op)(unsigned long addr, int len, void *arg),
-                     void *arg)
-{
-        int faulted, res;
-
-        faulted = setjmp_wrapper(do_buffer_op, addr, len, is_write, op, arg,
-                                 &res);
-        if (!faulted)
-                return res;
+        if (n != 0) {
+                remain = (n < 0 ? remain : 0);
+                goto out;
+        }
 
-        return addr + len - (unsigned long) current->thread.fault_addr;
+        return 0;
+ out:
+        return remain;
 }
 
 static int copy_chunk_from_user(unsigned long from, int len, void *arg)