Commit 6608b45a authored by Pawan Gupta's avatar Pawan Gupta Committed by Thomas Gleixner
Browse files

x86/speculation/taa: Add sysfs reporting for TSX Async Abort 



Add the sysfs reporting file for TSX Async Abort. It exposes the
vulnerability and the mitigation state similar to the existing files for
the other hardware vulnerabilities.

Sysfs file path is:
/sys/devices/system/cpu/vulnerabilities/tsx_async_abort

Signed-off-by: default avatarPawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Tested-by: default avatarNeelima Krishnan <neelima.krishnan@intel.com>
Reviewed-by: default avatarMark Gross <mgross@linux.intel.com>
Reviewed-by: default avatarTony Luck <tony.luck@intel.com>
Reviewed-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: default avatarJosh Poimboeuf <jpoimboe@redhat.com>
parent 1b42f017

arch/x86/kernel/cpu/bugs.c

+23 −0
Original line number Diff line number Diff line
@@ -1436,6 +1436,21 @@ static ssize_t mds_show_state(char *buf) 
		       sched_smt_active() ? "vulnerable" : "disabled");

}



static ssize_t tsx_async_abort_show_state(char *buf)

{

	if ((taa_mitigation == TAA_MITIGATION_TSX_DISABLED) ||

	    (taa_mitigation == TAA_MITIGATION_OFF))

		return sprintf(buf, "%s\n", taa_strings[taa_mitigation]);



	if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) {

		return sprintf(buf, "%s; SMT Host state unknown\n",

			       taa_strings[taa_mitigation]);

	}



	return sprintf(buf, "%s; SMT %s\n", taa_strings[taa_mitigation],

		       sched_smt_active() ? "vulnerable" : "disabled");

}



static char *stibp_state(void)

{

	if (spectre_v2_enabled == SPECTRE_V2_IBRS_ENHANCED)
@@ -1506,6 +1521,9 @@ static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr 
	case X86_BUG_MDS:

		return mds_show_state(buf);



	case X86_BUG_TAA:

		return tsx_async_abort_show_state(buf);



	default:

		break;

	}
@@ -1542,4 +1560,9 @@ ssize_t cpu_show_mds(struct device *dev, struct device_attribute *attr, char *bu 
{

	return cpu_show_common(dev, attr, buf, X86_BUG_MDS);

}



ssize_t cpu_show_tsx_async_abort(struct device *dev, struct device_attribute *attr, char *buf)

{

	return cpu_show_common(dev, attr, buf, X86_BUG_TAA);

}

#endif

drivers/base/cpu.c

+9 −0
Original line number Diff line number Diff line
@@ -554,12 +554,20 @@ ssize_t __weak cpu_show_mds(struct device *dev, 
	return sprintf(buf, "Not affected\n");

}



ssize_t __weak cpu_show_tsx_async_abort(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 DEVICE_ATTR(tsx_async_abort, 0444, cpu_show_tsx_async_abort, NULL);



static struct attribute *cpu_root_vulnerabilities_attrs[] = {

	&dev_attr_meltdown.attr,
@@ -568,6 +576,7 @@ static struct attribute *cpu_root_vulnerabilities_attrs[] = { 
	&dev_attr_spec_store_bypass.attr,

	&dev_attr_l1tf.attr,

	&dev_attr_mds.attr,

	&dev_attr_tsx_async_abort.attr,

	NULL

};

include/linux/cpu.h

+3 −0
Original line number Diff line number Diff line
@@ -59,6 +59,9 @@ 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 ssize_t cpu_show_tsx_async_abort(struct device *dev,

					struct device_attribute *attr,

					char *buf);



extern __printf(4, 5)

struct device *cpu_device_create(struct device *parent, void *drvdata,

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