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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: "Paul E. McKenney" <paulmck@kernel.org>,
	Sasha Levin <sashal@kernel.org>,
	frederic@kernel.org, quic_neeraju@quicinc.com,
	josh@joshtriplett.org, rcu@vger.kernel.org
Subject: [PATCH AUTOSEL 5.10 04/27] rcu: Suppress smp_processor_id() complaint in synchronize_rcu_expedited_wait()
Date: Sun, 26 Feb 2023 09:49:51 -0500	[thread overview]
Message-ID: <20230226145014.828855-4-sashal@kernel.org> (raw)
In-Reply-To: <20230226145014.828855-1-sashal@kernel.org>

From: "Paul E. McKenney" <paulmck@kernel.org>

[ Upstream commit 2d7f00b2f01301d6e41fd4a28030dab0442265be ]

The normal grace period's RCU CPU stall warnings are invoked from the
scheduling-clock interrupt handler, and can thus invoke smp_processor_id()
with impunity, which allows them to directly invoke dump_cpu_task().
In contrast, the expedited grace period's RCU CPU stall warnings are
invoked from process context, which causes the dump_cpu_task() function's
calls to smp_processor_id() to complain bitterly in debug kernels.

This commit therefore causes synchronize_rcu_expedited_wait() to disable
preemption around its call to dump_cpu_task().

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 kernel/rcu/tree_exp.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h
index 0dc16345e668c..ef6570137dcd5 100644
--- a/kernel/rcu/tree_exp.h
+++ b/kernel/rcu/tree_exp.h
@@ -564,7 +564,9 @@ static void synchronize_rcu_expedited_wait(void)
 				mask = leaf_node_cpu_bit(rnp, cpu);
 				if (!(READ_ONCE(rnp->expmask) & mask))
 					continue;
+				preempt_disable(); // For smp_processor_id() in dump_cpu_task().
 				dump_cpu_task(cpu);
+				preempt_enable();
 			}
 		}
 		jiffies_stall = 3 * rcu_jiffies_till_stall_check() + 3;
-- 
2.39.0


  parent reply	other threads:[~2023-02-26 15:35 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-02-26 14:49 [PATCH AUTOSEL 5.10 01/27] wifi: ath9k: Fix use-after-free in ath9k_hif_usb_disconnect() Sasha Levin
2023-02-26 14:49 ` [PATCH AUTOSEL 5.10 02/27] wifi: brcmfmac: Fix potential stack-out-of-bounds in brcmf_c_preinit_dcmds() Sasha Levin
2023-02-26 14:49 ` [PATCH AUTOSEL 5.10 03/27] rcu: Make RCU_LOCKDEP_WARN() avoid early lockdep checks Sasha Levin
2023-02-26 14:49 ` Sasha Levin [this message]
2023-02-26 14:49 ` [PATCH AUTOSEL 5.10 05/27] rcu-tasks: Make rude RCU-Tasks work well with CPU hotplug Sasha Levin
2023-02-26 14:49 ` [PATCH AUTOSEL 5.10 06/27] wifi: ath11k: debugfs: fix to work with multiple PCI devices Sasha Levin
2023-02-26 14:49 ` [PATCH AUTOSEL 5.10 07/27] thermal: intel: Fix unsigned comparison with less than zero Sasha Levin
2023-02-26 14:49 ` [PATCH AUTOSEL 5.10 08/27] timers: Prevent union confusion from unexpected restart_syscall() Sasha Levin
2023-02-26 14:49 ` [PATCH AUTOSEL 5.10 09/27] x86/bugs: Reset speculation control settings on init Sasha Levin
2023-02-26 14:49 ` [PATCH AUTOSEL 5.10 10/27] wifi: brcmfmac: ensure CLM version is null-terminated to prevent stack-out-of-bounds Sasha Levin
2023-02-26 14:49 ` [PATCH AUTOSEL 5.10 11/27] wifi: mt7601u: fix an integer underflow Sasha Levin
2023-02-26 14:49 ` [PATCH AUTOSEL 5.10 12/27] inet: fix fast path in __inet_hash_connect() Sasha Levin
2023-02-26 14:50 ` [PATCH AUTOSEL 5.10 13/27] ice: add missing checks for PF vsi type Sasha Levin
2023-02-26 14:50 ` [PATCH AUTOSEL 5.10 14/27] ACPI: Don't build ACPICA with '-Os' Sasha Levin
2023-02-26 14:50 ` [PATCH AUTOSEL 5.10 15/27] clocksource: Suspend the watchdog temporarily when high read latency detected Sasha Levin
2023-02-26 14:50 ` [PATCH AUTOSEL 5.10 16/27] crypto: hisilicon: Wipe entire pool on error Sasha Levin
2023-02-26 14:50 ` [PATCH AUTOSEL 5.10 17/27] netpoll: Remove 4s sleep during carrier detection Sasha Levin
2023-02-26 14:50 ` [PATCH AUTOSEL 5.10 18/27] net: bcmgenet: Add a check for oversized packets Sasha Levin
2023-02-26 14:50 ` [PATCH AUTOSEL 5.10 19/27] m68k: Check syscall_trace_enter() return code Sasha Levin
2023-02-26 14:50 ` [PATCH AUTOSEL 5.10 20/27] wifi: mt76: dma: free rx_head in mt76_dma_rx_cleanup Sasha Levin
2023-02-26 14:50 ` [PATCH AUTOSEL 5.10 21/27] ACPI: video: Fix Lenovo Ideapad Z570 DMI match Sasha Levin
2023-02-26 14:50 ` [PATCH AUTOSEL 5.10 22/27] net/mlx5: fw_tracer: Fix debug print Sasha Levin
2023-02-26 14:50 ` [PATCH AUTOSEL 5.10 23/27] coda: Avoid partial allocation of sig_inputArgs Sasha Levin
2023-02-26 14:50 ` [PATCH AUTOSEL 5.10 24/27] uaccess: Add minimum bounds check on kernel buffer size Sasha Levin
2023-02-26 14:50 ` [PATCH AUTOSEL 5.10 25/27] PM: EM: fix memory leak with using debugfs_lookup() Sasha Levin
2023-02-26 14:50 ` [PATCH AUTOSEL 5.10 26/27] Bluetooth: btusb: Add VID:PID 13d3:3529 for Realtek RTL8821CE Sasha Levin
2023-02-26 14:50 ` [PATCH AUTOSEL 5.10 27/27] devlink: health: Fix nla_nest_end in error flow Sasha Levin

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