author | Thomas Gleixner <tglx@linutronix.de> | 2019-02-18 21:51:43 (GMT) |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-05-14 17:19:40 (GMT) |
commit | ba08d562b066f044e2985ece32b7890f556ee5ed (patch) | |
tree | 6ad73e14da12bf7b0aefcb2bbf1ff243217f6d4c | |
parent | 4e722ae3141fc6aebadc722b3b10720e2ffd866f (diff) | |
download | common-ba08d562b066f044e2985ece32b7890f556ee5ed.zip common-ba08d562b066f044e2985ece32b7890f556ee5ed.tar.gz common-ba08d562b066f044e2985ece32b7890f556ee5ed.tar.bz2 |
x86/speculation/mds: Add sysfs reporting for MDS
commit 8a4b06d391b0a42a373808979b5028f5c84d9c6a upstream.
Add the sysfs reporting file for MDS. It exposes the vulnerability and
mitigation state similar to the existing files for the other speculative
hardware vulnerabilities.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jon Masters <jcm@redhat.com>
Tested-by: Jon Masters <jcm@redhat.com>
[bwh: Backported to 4.9: test x86_hyper instead of using hypervisor_is_type()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r-- | Documentation/ABI/testing/sysfs-devices-system-cpu | 1 | ||||
-rw-r--r-- | arch/x86/kernel/cpu/bugs.c | 28 | ||||
-rw-r--r-- | drivers/base/cpu.c | 8 | ||||
-rw-r--r-- | include/linux/cpu.h | 2 |
4 files changed, 39 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu index 069e8d5..b4ba4f1 100644 --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -357,6 +357,7 @@ What: /sys/devices/system/cpu/vulnerabilities /sys/devices/system/cpu/vulnerabilities/spectre_v2 /sys/devices/system/cpu/vulnerabilities/spec_store_bypass /sys/devices/system/cpu/vulnerabilities/l1tf + /sys/devices/system/cpu/vulnerabilities/mds Date: January 2018 Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> Description: Information about CPU vulnerabilities diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index ec91c156..fe374b2 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -25,6 +25,7 @@ #include <asm/vmx.h> #include <asm/paravirt.h> #include <asm/alternative.h> +#include <asm/hypervisor.h> #include <asm/pgtable.h> #include <asm/cacheflush.h> #include <asm/intel-family.h> @@ -1161,6 +1162,24 @@ static ssize_t l1tf_show_state(char *buf) } #endif +static ssize_t mds_show_state(char *buf) +{ +#ifdef CONFIG_HYPERVISOR_GUEST + if (x86_hyper) { + return sprintf(buf, "%s; SMT Host state unknown\n", + mds_strings[mds_mitigation]); + } +#endif + + if (boot_cpu_has(X86_BUG_MSBDS_ONLY)) { + return sprintf(buf, "%s; SMT %s\n", mds_strings[mds_mitigation], + sched_smt_active() ? "mitigated" : "disabled"); + } + + return sprintf(buf, "%s; SMT %s\n", mds_strings[mds_mitigation], + sched_smt_active() ? "vulnerable" : "disabled"); +} + static char *stibp_state(void) { if (spectre_v2_enabled == SPECTRE_V2_IBRS_ENHANCED) @@ -1222,6 +1241,10 @@ static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr if (boot_cpu_has(X86_FEATURE_L1TF_PTEINV)) return l1tf_show_state(buf); break; + + case X86_BUG_MDS: + return mds_show_state(buf); + default: break; } @@ -1253,4 +1276,9 @@ ssize_t cpu_show_l1tf(struct device *dev, struct device_attribute *attr, char *b { return cpu_show_common(dev, attr, buf, X86_BUG_L1TF); } + +ssize_t cpu_show_mds(struct device *dev, struct device_attribute *attr, char *buf) +{ + return cpu_show_common(dev, attr, buf, X86_BUG_MDS); +} #endif diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index f1f4ce7..3b123735 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -531,11 +531,18 @@ ssize_t __weak cpu_show_l1tf(struct device *dev, return sprintf(buf, "Not affected\n"); } +ssize_t __weak cpu_show_mds(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return sprintf(buf, "Not affected\n"); +} + static DEVICE_ATTR(meltdown, 0444, cpu_show_meltdown, NULL); static DEVICE_ATTR(spectre_v1, 0444, cpu_show_spectre_v1, NULL); static DEVICE_ATTR(spectre_v2, 0444, cpu_show_spectre_v2, NULL); static DEVICE_ATTR(spec_store_bypass, 0444, cpu_show_spec_store_bypass, NULL); static DEVICE_ATTR(l1tf, 0444, cpu_show_l1tf, NULL); +static DEVICE_ATTR(mds, 0444, cpu_show_mds, NULL); static struct attribute *cpu_root_vulnerabilities_attrs[] = { &dev_attr_meltdown.attr, @@ -543,6 +550,7 @@ static struct attribute *cpu_root_vulnerabilities_attrs[] = { &dev_attr_spectre_v2.attr, &dev_attr_spec_store_bypass.attr, &dev_attr_l1tf.attr, + &dev_attr_mds.attr, NULL }; diff --git a/include/linux/cpu.h b/include/linux/cpu.h index ae5ac89..1f88e86 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -54,6 +54,8 @@ extern ssize_t cpu_show_spec_store_bypass(struct device *dev, struct device_attribute *attr, char *buf); extern ssize_t cpu_show_l1tf(struct device *dev, struct device_attribute *attr, char *buf); +extern ssize_t cpu_show_mds(struct device *dev, + struct device_attribute *attr, char *buf); extern __printf(4, 5) struct device *cpu_device_create(struct device *parent, void *drvdata, |