linux-kernel - [PATCH 1/2] arm64: psci: Avoid printing in cpu_psci_cpu

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Message-Id: <20201106103602.9849-2-will@kernel.org>
Date:   Fri,  6 Nov 2020 10:36:01 +0000
From:   Will Deacon <will@...nel.org>
To:     linux-arm-kernel@...ts.infradead.org
Cc:     linux-kernel@...r.kernel.org, kernel-team@...roid.com,
        Will Deacon <will@...nel.org>,
        Catalin Marinas <catalin.marinas@....com>,
        Qian Cai <cai@...hat.com>,
        "Paul E. McKenney" <paulmck@...nel.org>
Subject: [PATCH 1/2] arm64: psci: Avoid printing in cpu_psci_cpu_die()

cpu_psci_cpu_die() is called in the context of the dying CPU, which
will no longer be online or tracked by RCU. It is therefore not generally
safe to call printk() if the PSCI "cpu off" request fails, so remove the
pr_crit() invocation.

Cc: Qian Cai <cai@...hat.com>
Cc: "Paul E. McKenney" <paulmck@...nel.org>
Cc: Catalin Marinas <catalin.marinas@....com>
Signed-off-by: Will Deacon <will@...nel.org>
---
 arch/arm64/kernel/psci.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c
index 43ae4e0c968f..6a4f3e37c3b4 100644
--- a/arch/arm64/kernel/psci.c
+++ b/arch/arm64/kernel/psci.c
@@ -75,8 +75,6 @@ static void cpu_psci_cpu_die(unsigned int cpu)
 		    PSCI_0_2_POWER_STATE_TYPE_SHIFT;
 
 	ret = psci_ops.cpu_off(state);
-
-	pr_crit("unable to power off CPU%u (%d)\n", cpu, ret);
 }
 
 static int cpu_psci_cpu_kill(unsigned int cpu)
-- 
2.29.1.341.ge80a0c044ae-goog