From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Qian Cai <cai@redhat.com>, Sasha Levin <sashal@kernel.org>,
Will Deacon <will@kernel.org>,
linux-arm-kernel@lists.infradead.org,
"Paul E . McKenney" <paulmck@kernel.org>
Subject: [PATCH AUTOSEL 5.8 29/29] arm64/smp: Move rcu_cpu_starting() earlier
Date: Mon, 2 Nov 2020 20:19:28 -0500 [thread overview]
Message-ID: <20201103011928.183145-29-sashal@kernel.org> (raw)
In-Reply-To: <20201103011928.183145-1-sashal@kernel.org>
From: Qian Cai <cai@redhat.com>
[ Upstream commit ce3d31ad3cac765484463b4f5a0b6b1f8f1a963e ]
The call to rcu_cpu_starting() in secondary_start_kernel() is not early
enough in the CPU-hotplug onlining process, which results in lockdep
splats as follows:
WARNING: suspicious RCU usage
-----------------------------
kernel/locking/lockdep.c:3497 RCU-list traversed in non-reader section!!
other info that might help us debug this:
RCU used illegally from offline CPU!
rcu_scheduler_active = 1, debug_locks = 1
no locks held by swapper/1/0.
Call trace:
dump_backtrace+0x0/0x3c8
show_stack+0x14/0x60
dump_stack+0x14c/0x1c4
lockdep_rcu_suspicious+0x134/0x14c
__lock_acquire+0x1c30/0x2600
lock_acquire+0x274/0xc48
_raw_spin_lock+0xc8/0x140
vprintk_emit+0x90/0x3d0
vprintk_default+0x34/0x40
vprintk_func+0x378/0x590
printk+0xa8/0xd4
__cpuinfo_store_cpu+0x71c/0x868
cpuinfo_store_cpu+0x2c/0xc8
secondary_start_kernel+0x244/0x318
This is avoided by moving the call to rcu_cpu_starting up near the
beginning of the secondary_start_kernel() function.
Signed-off-by: Qian Cai <cai@redhat.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/lkml/160223032121.7002.1269740091547117869.tip-bot2@tip-bot2/
Link: https://lore.kernel.org/r/20201028182614.13655-1-cai@redhat.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/arm64/kernel/smp.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 8cd6316a0d833..3e0fd4e6bcdcb 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -214,6 +214,7 @@ asmlinkage notrace void secondary_start_kernel(void)
if (system_uses_irq_prio_masking())
init_gic_priority_masking();
+ rcu_cpu_starting(cpu);
preempt_disable();
trace_hardirqs_off();
--
2.27.0
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prev parent reply other threads:[~2020-11-03 1:29 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-03 1:19 [PATCH AUTOSEL 5.8 01/29] ARM: dts: sun4i-a10: fix cpu_alert temperature Sasha Levin
2020-11-03 1:19 ` [PATCH AUTOSEL 5.8 02/29] arm64: dts: meson-axg: add USB nodes Sasha Levin
2020-11-03 1:19 ` [PATCH AUTOSEL 5.8 03/29] arm64: dts: meson-axg-s400: enable USB OTG Sasha Levin
2020-11-03 1:19 ` [PATCH AUTOSEL 5.8 04/29] arm64: dts: meson: add missing g12 rng clock Sasha Levin
2020-11-03 1:19 ` [PATCH AUTOSEL 5.8 05/29] arm64: dts: amlogic: meson-g12: use the G12A specific dwmac compatible Sasha Levin
2020-11-03 1:19 ` [PATCH AUTOSEL 5.8 10/29] ARM: dts: mmp3: Add power domain for the camera Sasha Levin
2020-11-03 1:19 ` [PATCH AUTOSEL 5.8 11/29] drm/sun4i: frontend: Rework a bit the phase data Sasha Levin
2020-11-03 1:19 ` [PATCH AUTOSEL 5.8 12/29] drm/sun4i: frontend: Reuse the ch0 phase for RGB formats Sasha Levin
2020-11-03 1:19 ` [PATCH AUTOSEL 5.8 13/29] drm/sun4i: frontend: Fix the scaler phase on A33 Sasha Levin
2020-11-03 1:19 ` Sasha Levin [this message]
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