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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/um/kernel/skas/uaccess.c
downloadblackbird-op-linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
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Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/um/kernel/skas/uaccess.c')
-rw-r--r--arch/um/kernel/skas/uaccess.c259
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 000000000000..7575ec489b63
--- /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:
+ */
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