vserver 1.9.3

[linux-2.6.git] / arch / um / kernel / skas / uaccess.c

diff --git a/arch/um/kernel/skas/uaccess.c b/arch/um/kernel/skas/uaccess.c
index ea82f19..77048cd 100644 (file)
--- a/arch/um/kernel/skas/uaccess.c
+++ b/arch/um/kernel/skas/uaccess.c
@@ -1,4 +1,4 @@
-/* 
+/*
  * Copyright (C) 2002 - 2003 Jeff Dike (jdike@addtoit.com)
  * Licensed under the GPL
  */
@@ -12,8 +12,9 @@
 #include "asm/pgtable.h"
 #include "asm/uaccess.h"
 #include "kern_util.h"
+#include "user_util.h"
 
-extern void *um_virt_to_phys(struct task_struct *task, unsigned long addr, 
+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)
@@ -25,7 +26,7 @@ static unsigned long maybe_map(unsigned long virt, int is_write)
        int dummy_code;
 
        if(IS_ERR(phys) || (is_write && !pte_write(pte))){
-               err = handle_page_fault(virt, 0, is_write, 0, &dummy_code);
+               err = handle_page_fault(virt, 0, is_write, 1, &dummy_code);
                if(err)
                        return(0);
                phys = um_virt_to_phys(current, virt, NULL);
@@ -33,7 +34,7 @@ static unsigned long maybe_map(unsigned long virt, int is_write)
        return((unsigned long) phys);
 }
 
-static int do_op(unsigned long addr, int len, int is_write, 
+static int do_op(unsigned long addr, int len, int is_write,
                 int (*op)(unsigned long addr, int len, void *arg), void *arg)
 {
        struct page *page;
@@ -51,37 +52,67 @@ static int do_op(unsigned long addr, int len, int is_write,
        return(n);
 }
 
-static int buffer_op(unsigned long addr, int len, int is_write,
-                    int (*op)(unsigned long addr, int len, void *arg),
-                    void *arg)
+static void do_buffer_op(void *jmpbuf, void *arg_ptr)
 {
+       va_list args = *((va_list *) arg_ptr);
+       unsigned long addr = va_arg(args, unsigned long);
+       int len = va_arg(args, int);
+       int is_write = va_arg(args, int);
+       int (*op)(unsigned long, int, void *) = va_arg(args, void *);
+       void *arg = va_arg(args, void *);
+       int *res = va_arg(args, int *);
        int size = min(PAGE_ALIGN(addr) - addr, (unsigned long) len);
        int remain = len, n;
 
+       current->thread.fault_catcher = jmpbuf;
        n = do_op(addr, size, is_write, op, arg);
-       if(n != 0)
-               return(n < 0 ? remain : 0);
+       if(n != 0){
+               *res = (n < 0 ? remain : 0);
+               goto out;
+       }
 
        addr += size;
        remain -= size;
-       if(remain == 0) 
-               return(0);
+       if(remain == 0){
+               *res = 0;
+               goto out;
+       }
 
        while(addr < ((addr + remain) & PAGE_MASK)){
                n = do_op(addr, PAGE_SIZE, is_write, op, arg);
-               if(n != 0)
-                       return(n < 0 ? remain : 0);
+               if(n != 0){
+                       *res = (n < 0 ? remain : 0);
+                       goto out;
+               }
 
                addr += PAGE_SIZE;
                remain -= PAGE_SIZE;
        }
-       if(remain == 0)
-               return(0);
+       if(remain == 0){
+               *res = 0;
+               goto out;
+       }
 
        n = do_op(addr, remain, is_write, op, arg);
        if(n != 0)
-               return(n < 0 ? remain : 0);
-       return(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);
+
+       return(addr + len - (unsigned long) current->thread.fault_addr);
 }
 
 static int copy_chunk_from_user(unsigned long from, int len, void *arg)
@@ -135,7 +166,7 @@ static int strncpy_chunk_from_user(unsigned long from, int len, void *arg)
        n = strnlen(to, len);
        *to_ptr += n;
 
-       if(n < len) 
+       if(n < len)
                return(1);
        return(0);
 }
@@ -153,7 +184,7 @@ int strncpy_from_user_skas(char *dst, const char *src, int count)
        if(!access_ok_skas(VERIFY_READ, src, 1))
                return(-EFAULT);
 
-       n = buffer_op((unsigned long) src, count, 0, strncpy_chunk_from_user, 
+       n = buffer_op((unsigned long) src, count, 0, strncpy_chunk_from_user,
                      &ptr);
        if(n != 0)
                return(-EFAULT);
@@ -178,7 +209,7 @@ int clear_user_skas(void *mem, int len)
                return(0);
        }
 
-       return(access_ok_skas(VERIFY_WRITE, mem, len) ? 
+       return(access_ok_skas(VERIFY_WRITE, mem, len) ?
               buffer_op((unsigned long) mem, len, 1, clear_chunk, NULL) : len);
 }