[PATCH v1 02/14] futex: Extend the FUTEX2 flags
From: Peter Zijlstra <peterz@infradead.org>
Date: 2023-07-21 11:01:05
Also in:
linux-arch, linux-mm, lkml
Add the definition for the missing but always intended extra sizes, and add a NUMA flag for the planned numa extention. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> --- include/uapi/linux/futex.h | 7 ++++--- kernel/futex/syscalls.c | 9 +++++++-- 2 files changed, 11 insertions(+), 5 deletions(-)
--- a/include/uapi/linux/futex.h
+++ b/include/uapi/linux/futex.h@@ -46,10 +46,11 @@ /* * Flags for futex2 syscalls. */ - /* 0x00 */ - /* 0x01 */ +#define FUTEX2_8 0x00 +#define FUTEX2_16 0x01 #define FUTEX2_32 0x02 - /* 0x04 */ +#define FUTEX2_64 0x03 +#define FUTEX2_NUMA 0x04 /* 0x08 */ /* 0x10 */ /* 0x20 */ --- a/kernel/futex/syscalls.c +++ b/kernel/futex/syscalls.c
@@ -183,7 +183,7 @@ SYSCALL_DEFINE6(futex, u32 __user *, uad return do_futex(uaddr, op, val, tp, uaddr2, (unsigned long)utime, val3); } -#define FUTEX2_MASK (FUTEX2_32 | FUTEX2_PRIVATE) +#define FUTEX2_MASK (FUTEX2_64 | FUTEX2_PRIVATE) /** * futex_parse_waitv - Parse a waitv array from userspace
@@ -207,7 +207,12 @@ static int futex_parse_waitv(struct fute if ((aux.flags & ~FUTEX2_MASK) || aux.__reserved) return -EINVAL; - if (!(aux.flags & FUTEX2_32)) + if (!IS_ENABLED(CONFIG_64BIT) || in_compat_syscall()) { + if ((aux.flags & FUTEX2_64) == FUTEX2_64) + return -EINVAL; + } + + if ((aux.flags & FUTEX2_64) != FUTEX2_32) return -EINVAL; futexv[i].w.flags = aux.flags;