[PATCH stable 4.9 14/23] powerpc/64s: Enhance the information in cpu_show_meltdown()
From: Michael Ellerman <mpe@ellerman.id.au>
Date: 2018-06-02 11:09:27
Also in:
stable
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
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@ellerman.id.au> --- arch/powerpc/kernel/security.c | 30 ++++++++++++++++++++++++++++-- 1 file changed, 28 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/kernel/security.c b/arch/powerpc/kernel/security.c
index 564e7f182a16..865db6f8bcca 100644
--- 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 __read_mostly = \ 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"); }
--
2.14.1