[PATCH 4.14 14/91] powerpc/security/book3s64: Report L1TF status in sysfs

Greg Kroah-Hartman
2020-01-02T22:51:47Z

From: Anthony Steinhauser <asteinhauser@google.com>

[ Upstream commit 8e6b6da91ac9b9ec5a925b6cb13f287a54bd547d ]

Some PowerPC CPUs are vulnerable to L1TF to the same extent as to
Meltdown. It is also mitigated by flushing the L1D on privilege
transition.

Currently the sysfs gives a false negative on L1TF on CPUs that I
verified to be vulnerable, a Power9 Talos II Boston 004e 1202, PowerNV
T2P9D01.

Signed-off-by: Anthony Steinhauser <asteinhauser@google.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
[mpe: Just have cpu_show_l1tf() call cpu_show_meltdown() directly]
Link: https://lore.kernel.org/r/20191029190759.84821-1-asteinhauser@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/powerpc/kernel/security.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/arch/powerpc/kernel/security.c b/arch/powerpc/kernel/security.c
index f5d6541bf8c2..fef3f09fc238 100644
--- a/arch/powerpc/kernel/security.c
+++ b/arch/powerpc/kernel/security.c
@@ -160,6 +160,11 @@ ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr, cha

return sprintf(buf, "Vulnerable\n");
}
+
+ssize_t cpu_show_l1tf(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ return cpu_show_meltdown(dev, attr, buf);
+}
#endif

ssize_t cpu_show_spectre_v1(struct device *dev, struct device_attribute *attr, char *buf)
--
2.20.1