Re: [PATCH v1 02/14] futex: Extend the FUTEX2 flags
From: "Arnd Bergmann" <arnd@arndb.de>
Date: 2023-07-21 15:48:04
Also in:
linux-arch, linux-mm, lkml
On Fri, Jul 21, 2023, at 12:22, Peter Zijlstra wrote:
quoted hunk ↗ jump to hunk
* 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;
This looks slightly confusing, how about defining another
FUTEX2_SIZEMASK (or similar) macro to clarify that
"aux.flags & FUTEX2_64" is a mask operation that can
match the FUTEX2_{8,16,32,64} values?
Arnd