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powerpc64s: Show ori31 availability in spectre_v1 sysfs file not v2

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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: d6fbe1c55c ("powerpc/64s: Wire up cpu_show_spectre_v2()")
Cc: stable@vger.kernel.org # v4.17+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Michael Ellerman 2018-07-09 16:25:21 +10:00
parent 5b73151fff
commit 6d44acae19
1 changed files with 17 additions and 10 deletions
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27
arch/powerpc/kernel/security.c
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@ -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;
if (barrier_nospec_enabled)
return sprintf(buf, "Mitigation: __user pointer sanitization\n");
seq_buf_init(&s, buf, PAGE_SIZE - 1);
return sprintf(buf, "Vulnerable\n");
if (security_ftr_enabled(SEC_FTR_BNDS_CHK_SPEC_BAR)) {
if (barrier_nospec_enabled)
seq_buf_printf(&s, "Mitigation: __user pointer sanitization");
else
seq_buf_printf(&s, "Vulnerable");
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;