From: Jinjie Ruan <ruanjinjie@huawei.com>
To: <viro@zeniv.linux.org.uk>, <brauner@kernel.org>, <jack@suse.cz>,
<bcrl@kvack.org>, <tytso@mit.edu>, <adilger.kernel@dilger.ca>,
<libaokun@linux.alibaba.com>, <ojaswin@linux.ibm.com>,
<ritesh.list@gmail.com>, <yi.zhang@huawei.com>,
<sforshee@kernel.org>, <pmladek@suse.com>, <rostedt@goodmis.org>,
<andriy.shevchenko@linux.intel.com>, <linux@rasmusvillemoes.dk>,
<senozhatsky@chromium.org>, <akpm@linux-foundation.org>,
<davem@davemloft.net>, <edumazet@google.com>, <kuba@kernel.org>,
<pabeni@redhat.com>, <horms@kernel.org>, <kuniyu@google.com>,
<willemb@google.com>, <jhs@mojatatu.com>, <jiri@resnulli.us>,
<kees@kernel.org>, <cyphar@cyphar.com>, <tglx@kernel.org>,
<ruanjinjie@huawei.com>, <sdf@fomichev.me>, <nb@tipi-net.de>,
<liuhangbin@gmail.com>, <da-x@monatomic.org>, <jeff@garzik.org>,
<linux-fsdevel@vger.kernel.org>, <linux-aio@kvack.org>,
<linux-kernel@vger.kernel.org>, <linux-ext4@vger.kernel.org>,
<netdev@vger.kernel.org>
Subject: [PATCH v2 05/12] pidfs: Use test_bit_acquire() for attr flag tests
Date: Tue, 1 Sep 2026 10:42:27 +0800 [thread overview]
Message-ID: <20260901024234.135119-6-ruanjinjie@huawei.com> (raw)
In-Reply-To: <20260901024234.135119-1-ruanjinjie@huawei.com>
Replace test_bit() + smp_rmb() with test_bit_acquire() for
PIDFS_ATTR_BIT_EXIT and PIDFS_ATTR_BIT_COREDUMP tests in pidfd_info().
The acquire semantics ensure that if the flag is observed set, the
associated attr fields written before smp_wmb() + set_bit() are
also visible.
Writers keep smp_wmb() + set_bit() since no release bitop exists.
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Assisted-by: DeepSeek:DeepSeek-V3
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
fs/pidfs.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/fs/pidfs.c b/fs/pidfs.c
index a6a643f15d08..2cd0fab73180 100644
--- a/fs/pidfs.c
+++ b/fs/pidfs.c
@@ -393,8 +393,7 @@ static long pidfd_info(struct file *file, unsigned int cmd, unsigned long arg)
attr = READ_ONCE(pid->attr);
if (mask & PIDFD_INFO_EXIT) {
- if (test_bit(PIDFS_ATTR_BIT_EXIT, &attr->attr_mask)) {
- smp_rmb();
+ if (test_bit_acquire(PIDFS_ATTR_BIT_EXIT, &attr->attr_mask)) {
kinfo.mask |= PIDFD_INFO_EXIT;
#ifdef CONFIG_CGROUPS
kinfo.cgroupid = attr->cgroupid;
@@ -405,8 +404,7 @@ static long pidfd_info(struct file *file, unsigned int cmd, unsigned long arg)
}
if (mask & PIDFD_INFO_COREDUMP) {
- if (test_bit(PIDFS_ATTR_BIT_COREDUMP, &attr->attr_mask)) {
- smp_rmb();
+ if (test_bit_acquire(PIDFS_ATTR_BIT_COREDUMP, &attr->attr_mask)) {
kinfo.mask |= PIDFD_INFO_COREDUMP | PIDFD_INFO_COREDUMP_SIGNAL | PIDFD_INFO_COREDUMP_CODE;
kinfo.coredump_mask = attr->coredump_mask;
kinfo.coredump_signal = attr->coredump_signal;
--
2.34.1
next prev parent reply other threads:[~2026-09-01 2:42 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-01 2:42 [PATCH v2 00/12] Convert barrier pairs to acquire/release for better performance Jinjie Ruan
2026-09-01 2:42 ` [PATCH v2 01/12] user_namespace: Use acquire/release for nr_extents synchronization Jinjie Ruan
2026-09-02 2:42 ` sashiko-bot
2026-09-01 2:42 ` [PATCH v2 02/12] lib/vsprintf: Use acquire/release for ptr_key publication Jinjie Ruan
2026-09-02 2:42 ` sashiko-bot
2026-09-01 2:42 ` [PATCH v2 03/12] fs: aio: Use acquire/release for ring->tail publication Jinjie Ruan
2026-09-02 2:42 ` sashiko-bot
2026-09-01 2:42 ` [PATCH v2 04/12] fs: Use acquire/release for fdtable resize synchronization Jinjie Ruan
2026-09-02 2:42 ` sashiko-bot
2026-09-01 2:42 ` Jinjie Ruan [this message]
2026-09-02 2:42 ` [PATCH v2 05/12] pidfs: Use test_bit_acquire() for attr flag tests sashiko-bot
2026-09-01 2:42 ` [PATCH v2 06/12] super: Use acquire for SB_BORN check in super_cache_count() Jinjie Ruan
2026-09-02 2:42 ` sashiko-bot
2026-09-01 2:42 ` [PATCH v2 07/12] ext4: Fix out-of-bounds read in ext4_get_group_info() Jinjie Ruan
2026-09-01 6:44 ` Zhang Yi
2026-09-01 13:55 ` Jan Kara
2026-09-02 2:42 ` sashiko-bot
2026-09-01 2:42 ` [PATCH v2 08/12] ext4: Convert group-count barrier protocol to acquire/release Jinjie Ruan
2026-09-02 2:42 ` sashiko-bot
2026-09-01 2:42 ` [PATCH v2 09/12] soreuseport: publish num_socks with acquire/release Jinjie Ruan
2026-09-02 2:42 ` sashiko-bot
2026-09-01 2:42 ` [PATCH v2 10/12] net: sched: act_gact: use acquire/release for tcfg_ptype Jinjie Ruan
2026-09-02 2:42 ` sashiko-bot
2026-09-01 2:42 ` [PATCH v2 11/12] 8021q: Fix data race when publishing vlan net_device pointers Jinjie Ruan
2026-09-01 14:58 ` Jakub Kicinski
2026-09-02 2:42 ` sashiko-bot
2026-09-01 2:42 ` [PATCH v2 12/12] 8021q: publish vlan_devices_arrays entries with acquire/release Jinjie Ruan
2026-09-02 2:42 ` sashiko-bot
2026-09-01 3:06 ` [PATCH v2 00/12] Convert barrier pairs to acquire/release for better performance Kuniyuki Iwashima
2026-09-01 3:15 ` Jinjie Ruan
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