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From: Muchun Song <songmuchun@bytedance.com>
To: corbet@lwn.net, mike.kravetz@oracle.com,
	akpm@linux-foundation.org, mcgrof@kernel.org,
	keescook@chromium.org, yzaikin@google.com
Cc: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-mm@kvack.org, duanxiongchun@bytedance.com,
	Muchun Song <songmuchun@bytedance.com>
Subject: [PATCH 2/3] sysctl: allow to set extra1 to SYSCTL_ONE
Date: Mon, 28 Feb 2022 15:10:21 +0800	[thread overview]
Message-ID: <20220228071022.26143-3-songmuchun@bytedance.com> (raw)
In-Reply-To: <20220228071022.26143-1-songmuchun@bytedance.com>

Some sysctls only allow to be enabled and cannot be set back to be
disabled. But proc_do_static_key() does not consider this situation,
which set ->extra1 to SYSCTL_ZERO unconditionally. This patch add
the ability to set ->extra1 to SYSCTL_ONE, which will be used in
the next patch.

Signed-off-by: Muchun Song <songmuchun@bytedance.com>
---
 kernel/sysctl.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 64065abf361e..ab3e9c937268 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1631,7 +1631,7 @@ int proc_do_static_key(struct ctl_table *table, int write,
 		.data   = &val,
 		.maxlen = sizeof(val),
 		.mode   = table->mode,
-		.extra1 = SYSCTL_ZERO,
+		.extra1 = table->extra1 == SYSCTL_ONE ? SYSCTL_ONE : SYSCTL_ZERO,
 		.extra2 = SYSCTL_ONE,
 	};
 
-- 
2.11.0


  parent reply	other threads:[~2022-02-28  7:11 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-02-28  7:10 [PATCH 0/3] add hugetlb_free_vmemmap sysctl Muchun Song
2022-02-28  7:10 ` [PATCH 1/3] mm: hugetlb: disable freeing vmemmap pages when struct page crosses page boundaries Muchun Song
2022-02-28  7:10 ` Muchun Song [this message]
2022-02-28  7:10 ` [PATCH 3/3] mm: hugetlb: add hugetlb_free_vmemmap sysctl Muchun Song
2022-02-28 14:41   ` Luis Chamberlain
2022-02-28 15:14     ` Muchun Song
2022-02-28 17:35   ` kernel test robot
2022-02-28 17:37   ` kernel test robot

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