[PATCH stable v4.4 50/52] powerpc/fsl: Update Spectre v2 reporting

Michael Ellerman mpe at ellerman.id.au
Mon Apr 22 00:20:35 AEST 2019


From: Diana Craciun <diana.craciun at nxp.com>

commit dfa88658fb0583abb92e062c7a9cd5a5b94f2a46 upstream.

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

Signed-off-by: Diana Craciun <diana.craciun at nxp.com>
Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
---
 arch/powerpc/kernel/security.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/security.c b/arch/powerpc/kernel/security.c
index 1fd1aabc1193..523466345d79 100644
--- a/arch/powerpc/kernel/security.c
+++ b/arch/powerpc/kernel/security.c
@@ -213,8 +213,11 @@ ssize_t cpu_show_spectre_v2(struct device *dev, struct device_attribute *attr, c
 
 		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");
 
-- 
2.20.1



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