[PATCH 4.14 052/107] powerpc/fsl: Update Spectre v2 reporting

From: Greg Kroah-Hartman
Date: Mon Apr 01 2019 - 13:55:50 EST


4.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Diana Craciun <diana.craciun@xxxxxxx>

commit dfa88658fb0583abb92e062c7a9cd5a5b94f2a46 upstream.

Report branch predictor state flush as a mitigation for
Spectre variant 2.

Signed-off-by: Diana Craciun <diana.craciun@xxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/kernel/security.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

--- a/arch/powerpc/kernel/security.c
+++ b/arch/powerpc/kernel/security.c
@@ -212,8 +212,11 @@ ssize_t cpu_show_spectre_v2(struct devic

if (count_cache_flush_type == COUNT_CACHE_FLUSH_HW)
seq_buf_printf(&s, "(hardware accelerated)");
- } else
+ } else if (btb_flush_enabled) {
+ seq_buf_printf(&s, "Mitigation: Branch predictor state flush");
+ } else {
seq_buf_printf(&s, "Vulnerable");
+ }

seq_buf_printf(&s, "\n");