[PATCH 4.19 093/114] arm64: Add sysfs vulnerability show for spectre-v1

[Greg Kroah-Hartman]

From: Mian Yousaf Kaukab <ykaukab@xxxxxxx>

[ Upstream commit 3891ebccace188af075ce143d8b072b65e90f695 ]

spectre-v1 has been mitigated and the mitigation is always active.
Report this to userspace via sysfs

Signed-off-by: Mian Yousaf Kaukab <ykaukab@xxxxxxx>
Signed-off-by: Jeremy Linton <jeremy.linton@xxxxxxx>
Reviewed-by: Andre Przywara <andre.przywara@xxxxxxx>
Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Tested-by: Stefan Wahren <stefan.wahren@xxxxxxxx>
Acked-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Signed-off-by: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 arch/arm64/kernel/cpu_errata.c |    6 ++++++
 1 file changed, 6 insertions(+)

--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -729,3 +729,9 @@ const struct arm64_cpu_capabilities arm6
 	{
 	}
 };
+
+ssize_t cpu_show_spectre_v1(struct device *dev, struct device_attribute *attr,
+			    char *buf)
+{
+	return sprintf(buf, "Mitigation: __user pointer sanitization\n");
+}