x86/cpu: Implement CPU vulnerabilites sysfs functions

Implement the CPU vulnerabilty show functions for meltdown, spectre_v1 and
spectre_v2.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linuxfoundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lkml.kernel.org/r/20180107214913.177414879@linutronix.de
(cherry picked from commit 61dc0f555b5c761cdafb0ba5bd41ecf22d68a4c4)
Orabug: 27353383
Signed-off-by: Kanth Ghatraju <kanth.ghatraju@oracle.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Conflicts:
	arch/x86/Kconfig

	Resolved conflicts to pick only the changes from the patches.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index faee499648cc7fcc81478370a9d93339126a14ca..0daf3ec56d690171b8d8712536026c39faa0f3fc 100644 (file)
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -54,6 +54,7 @@ config X86
        select HAVE_DMA_ATTRS
        select HAVE_DMA_CONTIGUOUS
        select HAVE_KRETPROBES
+       select GENERIC_CPU_VULNERABILITIES
        select GENERIC_EARLY_IOREMAP
        select HAVE_OPTPROBES
        select HAVE_KPROBES_ON_FTRACE

diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 4c7dd836304a0ba42a9890cb1093791794d3deb7..d178101e57b69c177166c9ff1c3e577034fc56d1 100644 (file)
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -9,6 +9,7 @@
  */
 #include <linux/init.h>
 #include <linux/utsname.h>
+#include <linux/cpu.h>
 #include <asm/bugs.h>
 #include <asm/processor.h>
 #include <asm/processor-flags.h>

diff --git a/arch/x86/kernel/cpu/bugs_64.c b/arch/x86/kernel/cpu/bugs_64.c
index 04f0fe5af83ec34bb4fd6ec09fd3cc8db1c7ee07..6a9b2a18156c1b4407c04dea8b9a0c88178cd0b8 100644 (file)
--- a/arch/x86/kernel/cpu/bugs_64.c
+++ b/arch/x86/kernel/cpu/bugs_64.c
@@ -31,3 +31,32 @@ void __init check_bugs(void)
        if (!direct_gbpages)
                set_memory_4k((unsigned long)__va(0), 1);
 }
+
+#ifdef CONFIG_SYSFS
+ssize_t cpu_show_meltdown(struct device *dev,
+                         struct device_attribute *attr, char *buf)
+{
+       if (!boot_cpu_has_bug(X86_BUG_CPU_MELTDOWN))
+               return sprintf(buf, "Not affected\n");
+       if (boot_cpu_has(X86_FEATURE_PTI))
+               return sprintf(buf, "Mitigation: PTI\n");
+       return sprintf(buf, "Vulnerable\n");
+}
+
+ssize_t cpu_show_spectre_v1(struct device *dev,
+                           struct device_attribute *attr, char *buf)
+{
+       if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V1))
+               return sprintf(buf, "Not affected\n");
+       return sprintf(buf, "Vulnerable\n");
+}
+
+ssize_t cpu_show_spectre_v2(struct device *dev,
+                           struct device_attribute *attr, char *buf)
+{
+       if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V2) ||
+           (ibrs_inuse && ibpb_inuse))
+               return sprintf(buf, "Not affected\n");
+       return sprintf(buf, "Vulnerable\n");
+}
+#endif