From 0609e200246bfd3b7516091c491bec4308349055 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Tue, 31 May 2022 09:53:42 +0100 Subject: [PATCH] ARM: 9209/1: Spectre-BHB: avoid pr_info() every time a CPU comes out of idle Jon reports that the Spectre-BHB init code is filling up the kernel log with spurious notifications about which mitigation has been enabled, every time any CPU comes out of a low power state. Given that Spectre-BHB mitigations are system wide, only a single mitigation can be enabled, and we already print an error if two types of CPUs coexist in a single system that require different Spectre-BHB mitigations. This means that the pr_info() that describes the selected mitigation does not need to be emitted for each CPU anyway, and so we can simply emit it only once. In order to clarify the above in the log message, update it to describe that the selected mitigation will be enabled on all CPUs, including ones that are unaffected. If another CPU comes up later that is affected and requires a different mitigation, we report an error as before. Fixes: b9baf5c8c5c3 ("ARM: Spectre-BHB workaround") Tested-by: Jon Hunter Signed-off-by: Ard Biesheuvel Signed-off-by: Russell King (Oracle) --- arch/arm/mm/proc-v7-bugs.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/arm/mm/proc-v7-bugs.c b/arch/arm/mm/proc-v7-bugs.c index fb9f3eb..9edb0c5 100644 --- a/arch/arm/mm/proc-v7-bugs.c +++ b/arch/arm/mm/proc-v7-bugs.c @@ -209,10 +209,10 @@ static int spectre_bhb_install_workaround(int method) return SPECTRE_VULNERABLE; spectre_bhb_method = method; - } - pr_info("CPU%u: Spectre BHB: using %s workaround\n", - smp_processor_id(), spectre_bhb_method_name(method)); + pr_info("CPU%u: Spectre BHB: enabling %s workaround for all CPUs\n", + smp_processor_id(), spectre_bhb_method_name(method)); + } return SPECTRE_MITIGATED; } -- 2.7.4