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selftests/powerpc/spectre_v2: Return skip code when miss_percent is high

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[ Upstream commit 3c42e9542050d49610077e083c7c3f5fd5e26820 ]

A mis-match between reported and actual mitigation is not restricted to the
Vulnerable case. The guest might also report the mitigation as "Software
count cache flush" and the host will still mitigate with branch cache
disabled.

So, instead of skipping depending on the detected mitigation, simply skip
whenever the detected miss_percent is the expected one for a fully
mitigated system, that is, above 95%.

Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211207130557.40566-1-cascardo@canonical.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Thadeu Lima de Souza Cascardo 2021-12-07 10:05:57 -03:00 committed by Greg Kroah-Hartman
parent 21125e0116
commit 044164b419
1 changed files with 1 additions and 1 deletions
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2
tools/testing/selftests/powerpc/security/spectre_v2.c
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@ -193,7 +193,7 @@ int spectre_v2_test(void)
* We are not vulnerable and reporting otherwise, so
* missing such a mismatch is safe.
*/
if (state == VULNERABLE)
if (miss_percent > 95)
return 4;
return 1;