From ff348355e9c72493947be337bb4fae4fc1a41eba Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Tue, 27 Mar 2018 23:01:49 +1100 Subject: [PATCH] powerpc/64s: Enhance the information in cpu_show_meltdown() 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 --- arch/powerpc/include/asm/security_features.h | 1 + arch/powerpc/kernel/security.c | 30 ++++++++++++++++++-- 2 files changed, 29 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/include/asm/security_features.h b/arch/powerpc/include/asm/security_features.h index db00ad2c72c2..400a9050e035 100644 --- a/arch/powerpc/include/asm/security_features.h +++ b/arch/powerpc/include/asm/security_features.h @@ -10,6 +10,7 @@ extern unsigned long powerpc_security_features; +extern bool rfi_flush; static inline void security_ftr_set(unsigned long feature) { 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 #include +#include #include @@ -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"); } -- 2.30.2