1 files changed, 259 insertions, 0 deletions
diff --git a/arch/um/kernel/skas/uaccess.c b/arch/um/kernel/skas/uaccess.c
new file mode 100644
index 00000000000..7575ec489b6
--- /dev/null
+++ b/arch/um/kernel/skas/uaccess.c
@@ -0,0 +1,259 @@
+/*
+ * Copyright (C) 2002 - 2003 Jeff Dike (jdike@addtoit.com)
+ * Licensed under the GPL
+ */
+
+#include "linux/stddef.h"
+#include "linux/kernel.h"
+#include "linux/string.h"
+#include "linux/fs.h"
+#include "linux/highmem.h"
+#include "asm/page.h"
+#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,
+			     pte_t *pte_out);
+
+static unsigned long maybe_map(unsigned long virt, int is_write)
+{
+	pte_t pte;
+	int err;
+
+	void *phys = um_virt_to_phys(current, virt, &pte);
+	int dummy_code;
+
+	if(IS_ERR(phys) || (is_write && !pte_write(pte))){
+		err = handle_page_fault(virt, 0, is_write, 1, &dummy_code);
+		if(err)
+			return(0);
+		phys = um_virt_to_phys(current, virt, NULL);
+	}
+	return((unsigned long) phys);
+}
+
+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;
+	int n;
+
+	addr = maybe_map(addr, is_write);
+	if(addr == -1)
+		return(-1);
+
+	page = phys_to_page(addr);
+	addr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
+	n = (*op)(addr, len, arg);
+	kunmap(page);
+
+	return(n);
+}
+
+static void do_buffer_op(void *jmpbuf, void *arg_ptr)
+{
+	va_list args;
+	unsigned long addr;
+	int len, is_write, size, remain, n;
+	int (*op)(unsigned long, int, void *);
+	void *arg;
+	int *res;
+
+	/* Some old gccs recognize __va_copy, but not va_copy */
+	__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);
+	size = min(PAGE_ALIGN(addr) - addr, (unsigned long) len);
+	remain = len;
+
+	current->thread.fault_catcher = jmpbuf;
+	n = do_op(addr, size, is_write, op, arg);
+	if(n != 0){
+		*res = (n < 0 ? remain : 0);
+		goto out;
+	}
+
+	addr += size;
+	remain -= size;
+	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){
+			*res = (n < 0 ? remain : 0);
+			goto out;
+		}
+
+		addr += PAGE_SIZE;
+		remain -= PAGE_SIZE;
+	}
+	if(remain == 0){
+		*res = 0;
+		goto out;
+	}
+
+	n = do_op(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);
+
+	return(addr + len - (unsigned long) current->thread.fault_addr);
+}
+
+static int copy_chunk_from_user(unsigned long from, int len, void *arg)
+{
+	unsigned long *to_ptr = arg, to = *to_ptr;
+
+	memcpy((void *) to, (void *) from, len);
+	*to_ptr += len;
+	return(0);
+}
+
+int copy_from_user_skas(void *to, const void __user *from, int n)
+{
+	if(segment_eq(get_fs(), KERNEL_DS)){
+		memcpy(to, (__force void*)from, n);
+		return(0);
+	}
+
+	return(access_ok_skas(VERIFY_READ, from, n) ?
+	       buffer_op((unsigned long) from, n, 0, copy_chunk_from_user, &to):
+	       n);
+}
+
+static int copy_chunk_to_user(unsigned long to, int len, void *arg)
+{
+	unsigned long *from_ptr = arg, from = *from_ptr;
+
+	memcpy((void *) to, (void *) from, len);
+	*from_ptr += len;
+	return(0);
+}
+
+int copy_to_user_skas(void __user *to, const void *from, int n)
+{
+	if(segment_eq(get_fs(), KERNEL_DS)){
+		memcpy((__force void*)to, from, n);
+		return(0);
+	}
+
+	return(access_ok_skas(VERIFY_WRITE, to, n) ?
+	       buffer_op((unsigned long) to, n, 1, copy_chunk_to_user, &from) :
+	       n);
+}
+
+static int strncpy_chunk_from_user(unsigned long from, int len, void *arg)
+{
+	char **to_ptr = arg, *to = *to_ptr;
+	int n;
+
+	strncpy(to, (void *) from, len);
+	n = strnlen(to, len);
+	*to_ptr += n;
+
+	if(n < len)
+	        return(1);
+	return(0);
+}
+
+int strncpy_from_user_skas(char *dst, const char __user *src, int count)
+{
+	int n;
+	char *ptr = dst;
+
+	if(segment_eq(get_fs(), KERNEL_DS)){
+		strncpy(dst, (__force void*)src, count);
+		return(strnlen(dst, count));
+	}
+
+	if(!access_ok_skas(VERIFY_READ, src, 1))
+		return(-EFAULT);
+
+	n = buffer_op((unsigned long) src, count, 0, strncpy_chunk_from_user,
+		      &ptr);
+	if(n != 0)
+		return(-EFAULT);
+	return(strnlen(dst, count));
+}
+
+static int clear_chunk(unsigned long addr, int len, void *unused)
+{
+	memset((void *) addr, 0, len);
+	return(0);
+}
+
+int __clear_user_skas(void __user *mem, int len)
+{
+	return(buffer_op((unsigned long) mem, len, 1, clear_chunk, NULL));
+}
+
+int clear_user_skas(void __user *mem, int len)
+{
+	if(segment_eq(get_fs(), KERNEL_DS)){
+		memset((__force void*)mem, 0, len);
+		return(0);
+	}
+
+	return(access_ok_skas(VERIFY_WRITE, mem, len) ?
+	       buffer_op((unsigned long) mem, len, 1, clear_chunk, NULL) : len);
+}
+
+static int strnlen_chunk(unsigned long str, int len, void *arg)
+{
+	int *len_ptr = arg, n;
+
+	n = strnlen((void *) str, len);
+	*len_ptr += n;
+
+	if(n < len)
+		return(1);
+	return(0);
+}
+
+int strnlen_user_skas(const void __user *str, int len)
+{
+	int count = 0, n;
+
+	if(segment_eq(get_fs(), KERNEL_DS))
+		return(strnlen((__force char*)str, len) + 1);
+
+	n = buffer_op((unsigned long) str, len, 0, strnlen_chunk, &count);
+	if(n == 0)
+		return(count + 1);
+	return(-EFAULT);
+}
+
+/*
+ * Overrides for Emacs so that we follow Linus's tabbing style.
+ * Emacs will notice this stuff at the end of the file and automatically
+ * adjust the settings for this buffer only.  This must remain at the end
+ * of the file.
+ * ---------------------------------------------------------------------------
+ * Local variables:
+ * c-file-style: "linux"
+ * End:
+ */