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author | Michael Ellerman <mpe@ellerman.id.au> | 2018-07-09 16:25:21 +1000 |
---|---|---|
committer | Michael Ellerman <mpe@ellerman.id.au> | 2018-07-24 22:03:15 +1000 |
commit | 6d44acae1937b81cf8115ada8958e04f601f3f2e (patch) | |
tree | 340a4ddde4c8406d99c164649d96a9aaec4be555 /arch/powerpc/kernel | |
parent | 5b73151fff63fb019db8171cb81c6c978533844b (diff) | |
download | linux-stable-6d44acae1937b81cf8115ada8958e04f601f3f2e.tar.gz linux-stable-6d44acae1937b81cf8115ada8958e04f601f3f2e.tar.bz2 linux-stable-6d44acae1937b81cf8115ada8958e04f601f3f2e.zip |
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: d6fbe1c55c55 ("powerpc/64s: Wire up cpu_show_spectre_v2()")
Cc: stable@vger.kernel.org # v4.17+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kernel')
-rw-r--r-- | arch/powerpc/kernel/security.c | 27 |
1 files changed, 17 insertions, 10 deletions
diff --git a/arch/powerpc/kernel/security.c b/arch/powerpc/kernel/security.c index a8b277362931..4cb8f1f7b593 100644 --- a/arch/powerpc/kernel/security.c +++ b/arch/powerpc/kernel/security.c @@ -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 (barrier_nospec_enabled) - return sprintf(buf, "Mitigation: __user pointer sanitization\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"); - 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; |