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filename=peterz-futex2-flags-1.patch X-Rspamd-Queue-Id: 231424003B X-Rspam-User: X-Stat-Signature: aoodqgznzofbi1mjgmihqrm4ji8aq9dc X-Rspamd-Server: rspam03 X-HE-Tag: 1695294057-277361 X-HE-Meta: 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 q9ZTp3Xy uS1Hoo5yWUEVoixIDp6OtcZwPqoNhaRSYCcqbjBEjF1lusGQRSGDJnjhnsh6Dn6QmofW/c8RZ2Pd99F/l0D7OC0phVAHOe5tXJJNJVUnSK2ClZFeMPPrNFKpBk6L1lnDlyMsP4DhOkIFSLFT0DPbPa10L6mVH5VsvI784a73MiPpjInKStr5WjC6Uj2HiNedi9MRXaFCwDZ/ykYBWT5sWcggExJJIYY1jJmHpemZrRQUcKcu7jk9sKh5dBenZYu6j7nZXplSvZgLTF7WMSy2xszaDok5jQrEKe89gO6H65KEz8oE25jChDrMXwuhh+hYRO1frKB0+RYhMn0yDPNsxqZW19Q== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: sys_futex_waitv() is part of the futex2 series (the first and only so far) of syscalls and has a flags field per futex (as opposed to flags being encoded in the futex op). This new flags field has a new namespace, which unfortunately isn't super explicit. Notably it currently takes FUTEX_32 and FUTEX_PRIVATE_FLAG. Introduce the FUTEX2 namespace to clarify this Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Thomas Gleixner Reviewed-by: André Almeida --- include/uapi/linux/futex.h | 16 +++++++++++++--- kernel/futex/syscalls.c | 7 +++---- 2 files changed, 16 insertions(+), 7 deletions(-) --- a/include/uapi/linux/futex.h +++ b/include/uapi/linux/futex.h @@ -44,10 +44,20 @@ FUTEX_PRIVATE_FLAG) /* - * Flags to specify the bit length of the futex word for futex2 syscalls. - * Currently, only 32 is supported. + * Flags for futex2 syscalls. */ -#define FUTEX_32 2 + /* 0x00 */ + /* 0x01 */ +#define FUTEX2_SIZE_U32 0x02 + /* 0x04 */ + /* 0x08 */ + /* 0x10 */ + /* 0x20 */ + /* 0x40 */ +#define FUTEX2_PRIVATE FUTEX_PRIVATE_FLAG + +/* do not use */ +#define FUTEX_32 FUTEX2_SIZE_U32 /* historical accident :-( */ /* * Max numbers of elements in a futex_waitv array --- a/kernel/futex/syscalls.c +++ b/kernel/futex/syscalls.c @@ -183,8 +183,7 @@ SYSCALL_DEFINE6(futex, u32 __user *, uad return do_futex(uaddr, op, val, tp, uaddr2, (unsigned long)utime, val3); } -/* Mask of available flags for each futex in futex_waitv list */ -#define FUTEXV_WAITER_MASK (FUTEX_32 | FUTEX_PRIVATE_FLAG) +#define FUTEX2_VALID_MASK (FUTEX2_SIZE_U32 | FUTEX2_PRIVATE) /** * futex_parse_waitv - Parse a waitv array from userspace @@ -205,10 +204,10 @@ static int futex_parse_waitv(struct fute if (copy_from_user(&aux, &uwaitv[i], sizeof(aux))) return -EFAULT; - if ((aux.flags & ~FUTEXV_WAITER_MASK) || aux.__reserved) + if ((aux.flags & ~FUTEX2_VALID_MASK) || aux.__reserved) return -EINVAL; - if (!(aux.flags & FUTEX_32)) + if (!(aux.flags & FUTEX2_SIZE_U32)) return -EINVAL; futexv[i].w.flags = aux.flags;