maccess: remove strncpy_from_unsafe

All users are gone now.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200521152301.2587579-16-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 1 insertions, 39 deletions

diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
index bb3ab8227850..4183e585dee6 100644
--- 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
index f784da7ed2ad..85d124628b0e 100644
--- 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)
@@ -158,35 +156,6 @@ 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.
  * @dst:   Destination address, in kernel space.  This buffer must be at
@@ -206,19 +175,13 @@ 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)
 {
-	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);