From 12fdbe23b2901fa84d0ef35d53aeec112a930edf Mon Sep 17 00:00:00 2001 From: Michael Kerrisk Date: Wed, 14 Jan 2015 12:11:41 +0100 Subject: [PATCH] futex.2: Rearrange order FUTEX_UNLOCK_PI in list of operations Signed-off-by: Michael Kerrisk --- man2/futex.2 | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/man2/futex.2 b/man2/futex.2 index 1c9e98ca4..dd5b5d1da 100644 --- a/man2/futex.2 +++ b/man2/futex.2 @@ -689,13 +689,20 @@ arguments are ignored. .\" Documentation/robust-futexes.txt, is not an error as such. However, .\" I'm not yet sure of how to describe it in the man page.) .TP -.BR FUTEX_UNLOCK_PI " (since Linux 2.6.18)" -.\" commit c87e2837be82df479a6bae9f155c43516d2feebc -.\" FIXME to complete -[As yet undocumented] -.TP .BR FUTEX_TRYLOCK_PI " (since Linux 2.6.18)" .\" commit c87e2837be82df479a6bae9f155c43516d2feebc +This operation tries to acquire the futex at +.IR uaddr . +It deals with the +situation where the TID value at +.I uaddr +is 0, but the +.B FUTEX_HAS_WAITER +bit is set. +User space cannot handle this race free. +.TP +.BR FUTEX_UNLOCK_PI " (since Linux 2.6.18)" +.\" commit c87e2837be82df479a6bae9f155c43516d2feebc .\" FIXME to complete [As yet undocumented] .TP