Commit 92613085 authored by André Almeida's avatar André Almeida Committed by Thomas Gleixner
Browse files

futex: Consistently use fshared as boolean 



Since fshared is only conveying true/false values, declare it as bool.

In get_futex_key() the usage of fshared can be restricted to the first part
of the function. If fshared is false the function is terminated early and
the subsequent code can use a constant 'true' instead of the variable.

Signed-off-by: default avatarAndré Almeida <andrealmeid@collabora.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200702202843.520764-5-andrealmeid@collabora.com
parent d7c5ed73

kernel/futex.c

+5 −5
Original line number Diff line number Diff line
@@ -476,7 +476,7 @@ static u64 get_inode_sequence_number(struct inode *inode) 
/**

 * get_futex_key() - Get parameters which are the keys for a futex

 * @uaddr:	virtual address of the futex

 * @fshared:	0 for a PROCESS_PRIVATE futex, 1 for PROCESS_SHARED

 * @fshared:	false for a PROCESS_PRIVATE futex, true for PROCESS_SHARED

 * @key:	address where result is stored.

 * @rw:		mapping needs to be read/write (values: FUTEX_READ,

 *              FUTEX_WRITE)
@@ -500,8 +500,8 @@ static u64 get_inode_sequence_number(struct inode *inode) 
 *

 * lock_page() might sleep, the caller should not hold a spinlock.

 */

static int

get_futex_key(u32 __user *uaddr, int fshared, union futex_key *key, enum futex_access rw)

static int get_futex_key(u32 __user *uaddr, bool fshared, union futex_key *key,

			 enum futex_access rw)

{

	unsigned long address = (unsigned long)uaddr;

	struct mm_struct *mm = current->mm;
@@ -538,7 +538,7 @@ get_futex_key(u32 __user *uaddr, int fshared, union futex_key *key, enum futex_a 


again:

	/* Ignore any VERIFY_READ mapping (futex common case) */

	if (unlikely(should_fail_futex(fshared)))

	if (unlikely(should_fail_futex(true)))

		return -EFAULT;



	err = get_user_pages_fast(address, 1, FOLL_WRITE, &page);
@@ -626,7 +626,7 @@ again: 
		 * A RO anonymous page will never change and thus doesn't make

		 * sense for futex operations.

		 */

		if (unlikely(should_fail_futex(fshared)) || ro) {

		if (unlikely(should_fail_futex(true)) || ro) {

			err = -EFAULT;

			goto out;

		}

CRA Git | Maintained and supported by SUSTech CRA and CCSE