From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8EE47CE79A9 for ; Tue, 19 Sep 2023 20:52:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233270AbjISUwZ (ORCPT ); Tue, 19 Sep 2023 16:52:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48284 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229690AbjISUwV (ORCPT ); Tue, 19 Sep 2023 16:52:21 -0400 Received: from 66-220-144-178.mail-mxout.facebook.com (66-220-144-178.mail-mxout.facebook.com [66.220.144.178]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3A50FBD for ; Tue, 19 Sep 2023 13:52:14 -0700 (PDT) Received: by devbig1114.prn1.facebook.com (Postfix, from userid 425415) id 51999C361C1D; Tue, 19 Sep 2023 13:51:59 -0700 (PDT) From: Stefan Roesch To: kernel-team@fb.com Cc: shr@devkernel.io, akpm@linux-foundation.org, david@redhat.com, hannes@cmpxchg.org, riel@surriel.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Carl Klemm Subject: [PATCH v1 1/2] mm/ksm: support fork/exec for prctl Date: Tue, 19 Sep 2023 13:51:57 -0700 Message-Id: <20230919205158.1897353-2-shr@devkernel.io> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20230919205158.1897353-1-shr@devkernel.io> References: <20230919205158.1897353-1-shr@devkernel.io> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org A process can enable KSM with the prctl system call. When the process is forked the KSM flag is inherited by the child process. However if the process is executing an exec system call directly after the fork, the KSM setting is cleared. This patch addresses this problem. Signed-off-by: Stefan Roesch Reported-by: Carl Klemm --- include/linux/sched/coredump.h | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/include/linux/sched/coredump.h b/include/linux/sched/coredum= p.h index 0ee96ea7a0e9..205aa9917394 100644 --- a/include/linux/sched/coredump.h +++ b/include/linux/sched/coredump.h @@ -87,8 +87,11 @@ static inline int get_dumpable(struct mm_struct *mm) =20 #define MMF_DISABLE_THP_MASK (1 << MMF_DISABLE_THP) =20 +#define MMF_VM_MERGE_ANY 29 +#define MMF_VM_MERGE_ANY_MASK (1 << MMF_VM_MERGE_ANY) + #define MMF_INIT_MASK (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK |\ - MMF_DISABLE_THP_MASK | MMF_HAS_MDWE_MASK) + MMF_DISABLE_THP_MASK | MMF_HAS_MDWE_MASK |\ + MMF_VM_MERGE_ANY_MASK) =20 -#define MMF_VM_MERGE_ANY 29 #endif /* _LINUX_SCHED_COREDUMP_H */ --=20 2.39.3