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 5BD38E7D0A2 for ; Thu, 21 Sep 2023 17:28:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230253AbjIUR2p (ORCPT ); Thu, 21 Sep 2023 13:28:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54970 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230249AbjIUR16 (ORCPT ); Thu, 21 Sep 2023 13:27:58 -0400 Received: from 66-220-144-179.mail-mxout.facebook.com (66-220-144-179.mail-mxout.facebook.com [66.220.144.179]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4A48224853 for ; Thu, 21 Sep 2023 10:11:30 -0700 (PDT) Received: by devbig1114.prn1.facebook.com (Postfix, from userid 425415) id 74B35C502489; Thu, 21 Sep 2023 09:47:11 -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 v3 1/2] mm/ksm: support fork/exec for prctl Date: Thu, 21 Sep 2023 09:47:08 -0700 Message-Id: <20230921164709.3627565-2-shr@devkernel.io> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20230921164709.3627565-1-shr@devkernel.io> References: <20230921164709.3627565-1-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 Fixes: d7597f59d1d3 ("mm: add new api to enable ksm per process") Reviewed-by: David Hildenbrand Reported-by: Carl Klemm Tested-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