From: Fabio Estevam <festevam@gmail.com>
To: s.hauer@pengutronix.de
Cc: barebox@lists.infradead.org
Subject: [PATCH] mx5: Implement Spectre v2 workaround for Cortex-A8
Date: Wed, 11 Jul 2018 19:29:38 -0300 [thread overview]
Message-ID: <1531348178-4168-1-git-send-email-festevam@gmail.com> (raw)
Since 4.18-rc1 kernel the following warning is seen on i.MX51 and
i.MX53:
CPU0: Spectre v2: firmware did not set auxiliary control register IBE bit, system vulnerable
Implement the suggested workaround by setting the IBE bit in the
auxiliary control register.
Based on commit 7b37a9c732bf ("ARM: Introduce ability to enable ACR::IBE
on Cortex-A8 for CVE-2017-5715") from U-Boot.
With this patch applied the kernel now reports:
CPU0: Spectre v2: using BPIALL workaround
Tested on a imx51 babbage.
Signed-off-by: Fabio Estevam <festevam@gmail.com>
---
arch/arm/include/asm/errata.h | 9 +++++++++
arch/arm/mach-imx/cpu_init.c | 3 ++-
2 files changed, 11 insertions(+), 1 deletion(-)
diff --git a/arch/arm/include/asm/errata.h b/arch/arm/include/asm/errata.h
index 98137b5..c0e0f5a 100644
--- a/arch/arm/include/asm/errata.h
+++ b/arch/arm/include/asm/errata.h
@@ -86,3 +86,12 @@ static inline void enable_arm_errata_845369_war(void)
"mcr p15, 0, r0, c15, c0, 1\n"
);
}
+
+static inline void enable_arm_errata_cortexa8_cve_2017_5715(void)
+{
+ __asm__ __volatile__ (
+ "mrc p15, 0, r0, c1, c0, 1\n"
+ "orr r0, r0, #1 << 6\n"
+ "mcr p15, 0, r0, c1, c0, 1\n"
+ );
+}
diff --git a/arch/arm/mach-imx/cpu_init.c b/arch/arm/mach-imx/cpu_init.c
index 5b93d12..e1d88c7 100644
--- a/arch/arm/mach-imx/cpu_init.c
+++ b/arch/arm/mach-imx/cpu_init.c
@@ -22,6 +22,7 @@ void imx5_cpu_lowlevel_init(void)
arm_cpu_lowlevel_init();
enable_arm_errata_709718_war();
+ enable_arm_errata_cortexa8_cve_2017_5715();
}
void imx6_cpu_lowlevel_init(void)
@@ -51,4 +52,4 @@ void vf610_cpu_lowlevel_init(void)
{
arm_cpu_lowlevel_init();
}
-#endif
\ No newline at end of file
+#endif
--
2.7.4
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next reply other threads:[~2018-07-11 22:29 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-11 22:29 Fabio Estevam [this message]
2018-07-12 8:49 ` Lucas Stach
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