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Commit 6d44acae authored by Michael Ellerman's avatar Michael Ellerman
Browse files

powerpc64s: Show ori31 availability in spectre_v1 sysfs file not v2 



When I added the spectre_v2 information in sysfs, I included the
availability of the ori31 speculation barrier.

Although the ori31 barrier can be used to mitigate v2, it's primarily
intended as a spectre v1 mitigation. Spectre v2 is mitigated by
hardware changes.

So rework the sysfs files to show the ori31 information in the
spectre_v1 file, rather than v2.

Currently we display eg:

  $ grep . spectre_v*
  spectre_v1:Mitigation: __user pointer sanitization
  spectre_v2:Mitigation: Indirect branch cache disabled, ori31 speculation barrier enabled

After:

  $ grep . spectre_v*
  spectre_v1:Mitigation: __user pointer sanitization, ori31 speculation barrier enabled
  spectre_v2:Mitigation: Indirect branch cache disabled

Fixes: d6fbe1c5 ("powerpc/64s: Wire up cpu_show_spectre_v2()")
Cc: stable@vger.kernel.org # v4.17+
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 5b73151f

arch/powerpc/kernel/security.c

+17 −10
Original line number Diff line number Diff line
@@ -117,25 +117,35 @@ ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr, cha 


ssize_t cpu_show_spectre_v1(struct device *dev, struct device_attribute *attr, char *buf)

{

	if (!security_ftr_enabled(SEC_FTR_BNDS_CHK_SPEC_BAR))

		return sprintf(buf, "Not affected\n");

	struct seq_buf s;



	seq_buf_init(&s, buf, PAGE_SIZE - 1);



	if (security_ftr_enabled(SEC_FTR_BNDS_CHK_SPEC_BAR)) {

		if (barrier_nospec_enabled)

		return sprintf(buf, "Mitigation: __user pointer sanitization\n");

			seq_buf_printf(&s, "Mitigation: __user pointer sanitization");

		else

			seq_buf_printf(&s, "Vulnerable");



	return sprintf(buf, "Vulnerable\n");

		if (security_ftr_enabled(SEC_FTR_SPEC_BAR_ORI31))

			seq_buf_printf(&s, ", ori31 speculation barrier enabled");



		seq_buf_printf(&s, "\n");

	} else

		seq_buf_printf(&s, "Not affected\n");



	return s.len;

}



ssize_t cpu_show_spectre_v2(struct device *dev, struct device_attribute *attr, char *buf)

{

	bool bcs, ccd, ori;

	struct seq_buf s;

	bool bcs, ccd;



	seq_buf_init(&s, buf, PAGE_SIZE - 1);



	bcs = security_ftr_enabled(SEC_FTR_BCCTRL_SERIALISED);

	ccd = security_ftr_enabled(SEC_FTR_COUNT_CACHE_DISABLED);

	ori = security_ftr_enabled(SEC_FTR_SPEC_BAR_ORI31);



	if (bcs || ccd) {

		seq_buf_printf(&s, "Mitigation: ");
@@ -151,9 +161,6 @@ ssize_t cpu_show_spectre_v2(struct device *dev, struct device_attribute *attr, c 
	} else

		seq_buf_printf(&s, "Vulnerable");



	if (ori)

		seq_buf_printf(&s, ", ori31 speculation barrier enabled");



	seq_buf_printf(&s, "\n");



	return s.len;