4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
commit ff348355e9c72493947be337bb4fae4fc1a41eba upstream.
Now that we have the security feature flags we can make the
information displayed in the "meltdown" file more informative.
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/kernel/security.c | 30 ++++++++++++++++++++++++++++--
1 file changed, 28 insertions(+), 2 deletions(-)
--- a/arch/powerpc/kernel/security.c
+++ b/arch/powerpc/kernel/security.c
@@ -6,6 +6,7 @@
#include <linux/kernel.h>
#include <linux/device.h>
+#include <linux/seq_buf.h>
#include <asm/security_features.h>
@@ -19,8 +20,33 @@ unsigned long powerpc_security_features
ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr, char *buf)
{
- if (rfi_flush)
- return sprintf(buf, "Mitigation: RFI Flush\n");
+ bool thread_priv;
+
+ thread_priv = security_ftr_enabled(SEC_FTR_L1D_THREAD_PRIV);
+
+ if (rfi_flush || thread_priv) {
+ struct seq_buf s;
+ seq_buf_init(&s, buf, PAGE_SIZE - 1);
+
+ seq_buf_printf(&s, "Mitigation: ");
+
+ if (rfi_flush)
+ seq_buf_printf(&s, "RFI Flush");
+
+ if (rfi_flush && thread_priv)
+ seq_buf_printf(&s, ", ");
+
+ if (thread_priv)
+ seq_buf_printf(&s, "L1D private per thread");
+
+ seq_buf_printf(&s, "\n");
+
+ return s.len;
+ }
+
+ if (!security_ftr_enabled(SEC_FTR_L1D_FLUSH_HV) &&
+ !security_ftr_enabled(SEC_FTR_L1D_FLUSH_PR))
+ return sprintf(buf, "Not affected\n");
return sprintf(buf, "Vulnerable\n");
}
