Commit fc3562d7 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Linus Torvalds
Browse files

maccess: move user access routines together 



Move kernel access vs user access routines together to ease upcoming
ifdefs.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarAndrew 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/20200521152301.2587579-18-hch@lst.de


Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 98a23609

mm/maccess.c

+56 −56
Original line number Diff line number Diff line
@@ -46,34 +46,6 @@ long probe_kernel_read(void *dst, const void *src, size_t size) 
}

EXPORT_SYMBOL_GPL(probe_kernel_read);



/**

 * probe_user_read(): safely attempt to read from a user-space location

 * @dst: pointer to the buffer that shall take the data

 * @src: address to read from. This must be a user address.

 * @size: size of the data chunk

 *

 * Safely read from user address @src to the buffer at @dst. If a kernel fault

 * happens, handle that and return -EFAULT.

 */

long probe_user_read(void *dst, const void __user *src, size_t size)

{

	long ret = -EFAULT;

	mm_segment_t old_fs = get_fs();



	set_fs(USER_DS);

	if (access_ok(src, size)) {

		pagefault_disable();

		ret = __copy_from_user_inatomic(dst, src, size);

		pagefault_enable();

	}

	set_fs(old_fs);



	if (ret)

		return -EFAULT;

	return 0;

}

EXPORT_SYMBOL_GPL(probe_user_read);



/**

 * probe_kernel_write(): safely attempt to write to a location

 * @dst: address to write to
@@ -99,34 +71,6 @@ long probe_kernel_write(void *dst, const void *src, size_t size) 
	return 0;

}



/**

 * probe_user_write(): safely attempt to write to a user-space location

 * @dst: address to write to

 * @src: pointer to the data that shall be written

 * @size: size of the data chunk

 *

 * Safely write to address @dst from the buffer at @src.  If a kernel fault

 * happens, handle that and return -EFAULT.

 */

long probe_user_write(void __user *dst, const void *src, size_t size)

{

	long ret = -EFAULT;

	mm_segment_t old_fs = get_fs();



	set_fs(USER_DS);

	if (access_ok(dst, size)) {

		pagefault_disable();

		ret = __copy_to_user_inatomic(dst, src, size);

		pagefault_enable();

	}

	set_fs(old_fs);



	if (ret)

		return -EFAULT;

	return 0;

}

EXPORT_SYMBOL_GPL(probe_user_write);



/**

 * strncpy_from_kernel_nofault: - Copy a NUL terminated string from unsafe

 *				 address.
@@ -170,6 +114,62 @@ long strncpy_from_kernel_nofault(char *dst, const void *unsafe_addr, long count) 
	return ret ? -EFAULT : src - unsafe_addr;

}



/**

 * probe_user_read(): safely attempt to read from a user-space location

 * @dst: pointer to the buffer that shall take the data

 * @src: address to read from. This must be a user address.

 * @size: size of the data chunk

 *

 * Safely read from user address @src to the buffer at @dst. If a kernel fault

 * happens, handle that and return -EFAULT.

 */

long probe_user_read(void *dst, const void __user *src, size_t size)

{

	long ret = -EFAULT;

	mm_segment_t old_fs = get_fs();



	set_fs(USER_DS);

	if (access_ok(src, size)) {

		pagefault_disable();

		ret = __copy_from_user_inatomic(dst, src, size);

		pagefault_enable();

	}

	set_fs(old_fs);



	if (ret)

		return -EFAULT;

	return 0;

}

EXPORT_SYMBOL_GPL(probe_user_read);



/**

 * probe_user_write(): safely attempt to write to a user-space location

 * @dst: address to write to

 * @src: pointer to the data that shall be written

 * @size: size of the data chunk

 *

 * Safely write to address @dst from the buffer at @src.  If a kernel fault

 * happens, handle that and return -EFAULT.

 */

long probe_user_write(void __user *dst, const void *src, size_t size)

{

	long ret = -EFAULT;

	mm_segment_t old_fs = get_fs();



	set_fs(USER_DS);

	if (access_ok(dst, size)) {

		pagefault_disable();

		ret = __copy_to_user_inatomic(dst, src, size);

		pagefault_enable();

	}

	set_fs(old_fs);



	if (ret)

		return -EFAULT;

	return 0;

}

EXPORT_SYMBOL_GPL(probe_user_write);



/**

 * strncpy_from_user_nofault: - Copy a NUL terminated string from unsafe user

 *				address.