Commit d6d08d24 authored by peterz@infradead.org's avatar peterz@infradead.org Committed by Peter Zijlstra
Browse files

futex: Extend the FUTEX2 flags 



Add the definition for the missing but always intended extra sizes,
and add a NUMA flag for the planned numa extention.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarAndré Almeida <andrealmeid@igalia.com>
Link: https://lore.kernel.org/r/20230921105247.617057368@noisy.programming.kicks-ass.net
parent 4923954b

include/uapi/linux/futex.h

+18 −3
Original line number Diff line number Diff line
@@ -45,17 +45,32 @@ 


/*

 * Flags for futex2 syscalls.

 *

 * NOTE: these are not pure flags, they can also be seen as:

 *

 *   union {

 *     u32  flags;

 *     struct {

 *       u32 size    : 2,

 *           numa    : 1,

 *                   : 4,

 *           private : 1;

 *     };

 *   };

 */

			/*	0x00 */

			/*	0x01 */

#define FUTEX2_SIZE_U8		0x00

#define FUTEX2_SIZE_U16		0x01

#define FUTEX2_SIZE_U32		0x02

			/*	0x04 */

#define FUTEX2_SIZE_U64		0x03

#define FUTEX2_NUMA		0x04

			/*	0x08 */

			/*	0x10 */

			/*	0x20 */

			/*	0x40 */

#define FUTEX2_PRIVATE		FUTEX_PRIVATE_FLAG



#define FUTEX2_SIZE_MASK	0x03



/* do not use */

#define FUTEX_32		FUTEX2_SIZE_U32 /* historical accident :-( */

kernel/futex/syscalls.c

+7 −2
Original line number Diff line number Diff line
@@ -183,7 +183,7 @@ SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val, 
	return do_futex(uaddr, op, val, tp, uaddr2, (unsigned long)utime, val3);

}



#define FUTEX2_VALID_MASK (FUTEX2_SIZE_U32 | FUTEX2_PRIVATE)

#define FUTEX2_VALID_MASK (FUTEX2_SIZE_MASK | FUTEX2_PRIVATE)



/**

 * futex_parse_waitv - Parse a waitv array from userspace
@@ -207,7 +207,12 @@ static int futex_parse_waitv(struct futex_vector *futexv, 
		if ((aux.flags & ~FUTEX2_VALID_MASK) || aux.__reserved)

			return -EINVAL;



		if (!(aux.flags & FUTEX2_SIZE_U32))

		if (!IS_ENABLED(CONFIG_64BIT) || in_compat_syscall()) {

			if ((aux.flags & FUTEX2_SIZE_MASK) == FUTEX2_SIZE_U64)

				return -EINVAL;

		}



		if ((aux.flags & FUTEX2_SIZE_MASK) != FUTEX2_SIZE_U32)

			return -EINVAL;



		futexv[i].w.flags = aux.flags;