From: Kurt Kanzenbach <kurt@linutronix.de>
Date: Fri, 25 Jun 2021 08:10:59 +0000 (+0200)
Subject: Linux: Add FUTEX_LOCK_PI2
X-Git-Tag: glibc-2.35~463
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=dd5adb515c105e4ad1619825babe85d75a7a755c;p=thirdparty%2Fglibc.git

Linux: Add FUTEX_LOCK_PI2

Linux v5.14.0 introduced a new futex operation called FUTEX_LOCK_PI2.

This kernel feature can be used to implement
pthread_mutex_clocklock(MONOTONIC)/PI.

Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
---

diff --git a/sysdeps/unix/sysv/linux/kernel-features.h b/sysdeps/unix/sysv/linux/kernel-features.h
index 3930e143224..ffb6af196b8 100644
--- a/sysdeps/unix/sysv/linux/kernel-features.h
+++ b/sysdeps/unix/sysv/linux/kernel-features.h
@@ -220,4 +220,12 @@
 # define __ASSUME_FACCESSAT2 0
 #endif
 
+/* The FUTEX_LOCK_PI2 operation was introduced across all architectures in Linux
+   5.14.  */
+#if __LINUX_KERNEL_VERSION >= 0x050e00
+# define __ASSUME_FUTEX_LOCK_PI2 1
+#else
+# define __ASSUME_FUTEX_LOCK_PI2 0
+#endif
+
 #endif /* kernel-features.h */