linux-kernel - [PATCH v3 0/1] mm/mempolicy.c: forbid static or relative flags for local NUMA mode

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20161027163037.4089-1-kwapulinski.piotr@gmail.com>
Date:   Thu, 27 Oct 2016 18:30:37 +0200
From:   Piotr Kwapulinski <kwapulinski.piotr@...il.com>
To:     akpm@...ux-foundation.org
Cc:     kirill.shutemov@...ux.intel.com, vbabka@...e.cz,
        rientjes@...gle.com, mhocko@...e.com, liangchen.linux@...il.com,
        mgorman@...hsingularity.net, dave.hansen@...ux.intel.com,
        nzimmer@....com, linux-mm@...ck.org, linux-kernel@...r.kernel.org,
        linux-api@...r.kernel.org, kwapulinski.piotr@...il.com
Subject: [PATCH v3 0/1] mm/mempolicy.c: forbid static or relative flags for local NUMA mode

The MPOL_F_STATIC_NODES and MPOL_F_RELATIVE_NODES flags are irrelevant
when setting them for MPOL_LOCAL NUMA memory policy via set_mempolicy
or mbind.
Return the "invalid argument" from set_mempolicy and mbind whenever
any of these flags is passed along with MPOL_LOCAL.
It is consistent with MPOL_PREFERRED passed with empty nodemask.
It slightly shortens the execution time in paths where these flags
are used e.g. when trying to rebind the NUMA nodes for changes in
cgroups cpuset mems (mpol_rebind_preferred()) or when just printing
the mempolicy structure (/proc/PID/numa_maps).
Isolated tests done.

Signed-off-by: Piotr Kwapulinski <kwapulinski.piotr@...il.com>
---
Changes since V2:
Information from Documentation/vm/numa_memory_policy.txt removed.
Please let me know what else I should do to let this patch to be
accepted.
---
 mm/mempolicy.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 0b859af..266893e 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -276,7 +276,9 @@ static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags,
 				return ERR_PTR(-EINVAL);
 		}
 	} else if (mode == MPOL_LOCAL) {
-		if (!nodes_empty(*nodes))
+		if (!nodes_empty(*nodes) ||
+		    (flags & MPOL_F_STATIC_NODES) ||
+		    (flags & MPOL_F_RELATIVE_NODES))
 			return ERR_PTR(-EINVAL);
 		mode = MPOL_PREFERRED;
 	} else if (nodes_empty(*nodes))
-- 
2.10.0