x86/spectre: Report get_user mitigation for spectre_v1

Reflect the presence of get_user(), __get_user(), and 'syscall' protections
in sysfs. The expectation is that new and better tooling will allow the
kernel to grow more usages of array_index_nospec(), for now, only claim
mitigation for __user pointer de-references.

Reported-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: kernel-hardening@lists.openwall.com
Cc: gregkh@linuxfoundation.org
Cc: torvalds@linux-foundation.org
Cc: alan@linux.intel.com
Link: https://lkml.kernel.org/r/151727420158.33451.11658324346540434635.stgit@dwillia2-desk3.amr.corp.intel.com

diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 400c34ec9179af7e1c6b5fbd8581e9b430028096..fdb6068a23b51e189ba1e840616b21cb6149a559 100644 (file)
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -297,7 +297,7 @@ ssize_t cpu_show_spectre_v1(struct device *dev,
 {
        if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V1))
                return sprintf(buf, "Not affected\n");
-       return sprintf(buf, "Vulnerable\n");
+       return sprintf(buf, "Mitigation: __user pointer sanitization\n");
 }
 
 ssize_t cpu_show_spectre_v2(struct device *dev,