From 9f6c40c0e6cb8b27c4727cb9c099559007dc2d3a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=D0=9C=D0=B0=D1=80=D0=BA=20=D0=9A=D0=BE=D1=80=D0=B5=D0=BD?=
 =?UTF-8?q?=D0=B1=D0=B5=D1=80=D0=B3?= <socketpair@gmail.com>
Date: Mon, 13 Aug 2012 14:25:13 +0200
Subject: [PATCH] futex.2: Consolidate error descriptions to ERRORS

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
---
 man2/futex.2 | 39 ++++++++++++++++++++++++---------------
 1 file changed, 24 insertions(+), 15 deletions(-)

diff --git a/man2/futex.2 b/man2/futex.2
index 0235cbc74..fed044922 100644
--- a/man2/futex.2
+++ b/man2/futex.2
@@ -165,8 +165,6 @@ but first checks whether the location
 .I uaddr
 still contains the value
 .IR val3 .
-If not, the operation fails with the error
-.BR EAGAIN .
 The argument
 .I timeout
 is ignored.
@@ -179,18 +177,6 @@ the returned value for a successful call can have differing meanings.
 Returns 0 if the process was woken by a
 .B FUTEX_WAKE
 call.
-In case of timeout,
-the operation fails with the error
-.BR ETIMEDOUT .
-If the futex was not equal to the expected value,
-the operation fails with the error
-.BR EWOULDBLOCK .
-Signals (see
-.BR signal (7))
-or other spurious wakeups cause
-.B FUTEX_WAIT
-to fail with the error
-.BR EINTR .
 .TP
 .B FUTEX_WAKE
 Returns the number of processes woken up.
@@ -214,7 +200,10 @@ No read access to futex memory.
 .TP
 .B EAGAIN
 .B FUTEX_CMP_REQUEUE
-found an unexpected futex value.
+detect that the value at
+.I uaddr
+is not equal to the expected value
+.IR val3 .
 (This probably indicates a race;
 use the safe
 .B FUTEX_WAKE
@@ -225,6 +214,12 @@ Error in getting
 .I timeout
 information from userspace.
 .TP
+.B EINTR
+.B FUTEX_WAIT
+operation was interrupted by signal (see
+.BR signal (7)
+) or by other spurious wakeup.
+.TP
 .B EINVAL
 An operation was not defined or error in page alignment.
 .TP
@@ -234,6 +229,20 @@ The system limit on the total number of open files has been reached.
 .B ENOSYS
 Invalid operation specified in
 .IR op .
+.TP
+.B ETIMEDOUT
+Timeout during the
+.B FUTEX_WAIT
+operation.
+.TP
+.B EWOULDBLOCK
+The value, pointed to by
+.I uaddr
+was not equal to the expected value
+.I val
+at the moment of calling
+.B FUTEX_WAIT
+operation.
 .SH "VERSIONS"
 .PP
 Initial futex support was merged in Linux 2.5.7 but with different semantics