From efbc6af349794e270ca88788ab6db62b0fdf22d2 Mon Sep 17 00:00:00 2001 From: Jiri Kosina Date: Tue, 25 Sep 2018 14:39:28 +0200 Subject: [PATCH] x86/speculation: Propagate information about RSB filling mitigation to sysfs commit bb4b3b7762735cdaba5a40fd94c9303d9ffa147a upstream. If spectrev2 mitigation has been enabled, RSB is filled on context switch in order to protect from various classes of spectrev2 attacks. If this mitigation is enabled, say so in sysfs for spectrev2. Signed-off-by: Jiri Kosina Signed-off-by: Thomas Gleixner Cc: Peter Zijlstra Cc: Josh Poimboeuf Cc: Andrea Arcangeli Cc: "WoodhouseDavid" Cc: Andi Kleen Cc: Tim Chen Cc: "SchauflerCasey" Link: https://lkml.kernel.org/r/nycvar.YFH.7.76.1809251438580.15880@cbobk.fhfr.pm Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/cpu/bugs.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index fc1c1cbc3627..03ebc0adcd82 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -869,10 +869,11 @@ static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr return sprintf(buf, "Mitigation: __user pointer sanitization\n"); case X86_BUG_SPECTRE_V2: - ret = sprintf(buf, "%s%s%s%s%s\n", spectre_v2_strings[spectre_v2_enabled], + ret = sprintf(buf, "%s%s%s%s%s%s\n", spectre_v2_strings[spectre_v2_enabled], boot_cpu_has(X86_FEATURE_USE_IBPB) ? ", IBPB" : "", boot_cpu_has(X86_FEATURE_USE_IBRS_FW) ? ", IBRS_FW" : "", (x86_spec_ctrl_base & SPEC_CTRL_STIBP) ? ", STIBP" : "", + boot_cpu_has(X86_FEATURE_RSB_CTXSW) ? ", RSB filling" : "", spectre_v2_module_string()); return ret;