[PATCH 4.9 40/61] powerpc/64s: Wire up cpu_show_spectre_v1()

Greg Kroah-Hartman
2018-06-05T17:06:07Z

From: Michael Ellerman <mpe@ellerman.id.au>

commit 56986016cb8cd9050e601831fe89f332b4e3c46e upstream.

Add a definition for cpu_show_spectre_v1() to override the generic
version. Currently this just prints "Not affected" or "Vulnerable"
based on the firmware flag.

Although the kernel does have array_index_nospec() in a few places, we
haven't yet audited all the powerpc code to see where it's necessary,
so for now we don't list that as a mitigation.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/powerpc/kernel/security.c | 8 ++++++++
1 file changed, 8 insertions(+)

--- a/arch/powerpc/kernel/security.c
+++ b/arch/powerpc/kernel/security.c
@@ -50,3 +50,11 @@ ssize_t cpu_show_meltdown(struct device

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