From fd376c6b2a3ddf63b8444cda0f57587daaa6b45b Mon Sep 17 00:00:00 2001 From: Michael Kerrisk Date: Wed, 14 Oct 2020 08:05:15 +0200 Subject: [PATCH] seccomp.2, seccomp_unotify.2: Clarify that there can be only one SECCOMP_FILTER_FLAG_NEW_LISTENER Reported-by: Christian Brauner Signed-off-by: Michael Kerrisk --- man2/seccomp.2 | 11 +++++++++++ man2/seccomp_unotify.2 | 1 + 2 files changed, 12 insertions(+) diff --git a/man2/seccomp.2 b/man2/seccomp.2 index 1de791ce5..35eb1dd1f 100644 --- a/man2/seccomp.2 +++ b/man2/seccomp.2 @@ -225,6 +225,11 @@ return a new user-space notification file descriptor. When the filter returns .BR SECCOMP_RET_USER_NOTIF a notification will be sent to this file descriptor. +.IP +At most one seccomp filter using the +.BR SECCOMP_FILTER_FLAG_NEW_LISTENER +flag can be installed for a thread. +.IP See .BR seccomp_unotify (2) for further details. @@ -801,6 +806,12 @@ capability in its user namespace, or had not set before using .BR SECCOMP_SET_MODE_FILTER . .TP +.BR EBUSY +While installing a new filter, the +.BR SECCOMP_FILTER_FLAG_NEW_LISTENER +flag was specified, +but a previous filter had already been installed with that flag. +.TP .BR EFAULT .IR args was not a valid address. diff --git a/man2/seccomp_unotify.2 b/man2/seccomp_unotify.2 index f31ac5379..a85ec5ac5 100644 --- a/man2/seccomp_unotify.2 +++ b/man2/seccomp_unotify.2 @@ -92,6 +92,7 @@ Consequently, the return value of the (successful) .BR seccomp (2) call is a new "listening" file descriptor that can be used to receive notifications. +Only one such "listener" can be established. .IP \(bu In cases where it is appropriate, the seccomp filter returns the action value .BR SECCOMP_RET_USER_NOTIF .