maccess: remove strncpy_from_unsafe

All users are gone now. Signed-off-by: Christoph Hellwig <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Cc: Alexei Starovoitov <[email protected]> Cc: Daniel Borkmann <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Masami Hiramatsu <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Linus Torvalds <[email protected]>
nelseric · Jun 9, 2020 · 7676fbf · 7676fbf
1 parent 9de1fec
commit 7676fbf
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Showing 2 changed files with 1 addition and 39 deletions.
diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
@@ -311,7 +311,6 @@ extern long probe_user_read(void *dst, const void __user *src, size_t size);
 extern long notrace probe_kernel_write(void *dst, const void *src, size_t size);
 extern long notrace probe_user_write(void __user *dst, const void *src, size_t size);
 
-extern long strncpy_from_unsafe(char *dst, const void *unsafe_addr, long count);
 long strncpy_from_kernel_nofault(char *dst, const void *unsafe_addr,
 		long count);
 

diff --git a/mm/maccess.c b/mm/maccess.c
@@ -8,8 +8,6 @@
 
 static long __probe_kernel_read(void *dst, const void *src, size_t size,
 		bool strict);
-static long __strncpy_from_unsafe(char *dst, const void *unsafe_addr,
-		long count, bool strict);
 
 bool __weak probe_kernel_read_allowed(const void *unsafe_src, size_t size,
 		bool strict)
@@ -157,35 +155,6 @@ long probe_user_write(void __user *dst, const void *src, size_t size)
 }
 EXPORT_SYMBOL_GPL(probe_user_write);
 
-/**
- * strncpy_from_unsafe: - Copy a NUL terminated string from unsafe address.
- * @dst:   Destination address, in kernel space.  This buffer must be at
- *         least @count bytes long.
- * @unsafe_addr: Unsafe address.
- * @count: Maximum number of bytes to copy, including the trailing NUL.
- *
- * Copies a NUL-terminated string from unsafe address to kernel buffer.
- *
- * On success, returns the length of the string INCLUDING the trailing NUL.
- *
- * If access fails, returns -EFAULT (some data may have been copied
- * and the trailing NUL added).
- *
- * If @count is smaller than the length of the string, copies @count-1 bytes,
- * sets the last byte of @dst buffer to NUL and returns @count.
- *
- * Same as strncpy_from_kernel_nofault() except that for architectures with
- * not fully separated user and kernel address spaces this function also works
- * for user address tanges.
- *
- * DO NOT USE THIS FUNCTION - it is broken on architectures with entirely
- * separate kernel and user address spaces, and also a bad idea otherwise.
- */
-long strncpy_from_unsafe(char *dst, const void *unsafe_addr, long count)
-{
-	return __strncpy_from_unsafe(dst, unsafe_addr, count, false);
-}
-
 /**
  * strncpy_from_kernel_nofault: - Copy a NUL terminated string from unsafe
  *				 address.
@@ -205,20 +174,14 @@ long strncpy_from_unsafe(char *dst, const void *unsafe_addr, long count)
  * sets the last byte of @dst buffer to NUL and returns @count.
  */
 long strncpy_from_kernel_nofault(char *dst, const void *unsafe_addr, long count)
-{
-	return __strncpy_from_unsafe(dst, unsafe_addr, count, true);
-}
-
-static long __strncpy_from_unsafe(char *dst, const void *unsafe_addr,
-		long count, bool strict)
 {
 	mm_segment_t old_fs = get_fs();
 	const void *src = unsafe_addr;
 	long ret;
 
 	if (unlikely(count <= 0))
 		return 0;
-	if (!probe_kernel_read_allowed(unsafe_addr, count, strict))
+	if (!probe_kernel_read_allowed(unsafe_addr, count, true))
 		return -EFAULT;
 
 	set_fs(KERNEL_DS);