[PATCH 4.14 28/46] arm64: hibernate: Clean the __hyp_text to PoC after resume

Greg Kroah-Hartman
2019-02-04T10:46:23Z

From: James Morse <james.morse@arm.com>

commit f7daa9c8fd191724b9ab9580a7be55cd1a67d799 upstream.

During resume hibernate restores all physical memory. Any memory
that is accessed with the MMU disabled needs to be cleaned to the
PoC.

KVMs __hyp_text was previously ommitted as it runs with the MMU
enabled, but now that the hyp-stub is located in this section,
we must clean __hyp_text too.

This ensures secondary CPUs that come online after hibernate
has finished resuming, and load KVM via the freshly written
hyp-stub see the correct instructions.

Signed-off-by: James Morse <james.morse@arm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/arm64/kernel/hibernate.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

--- a/arch/arm64/kernel/hibernate.c
+++ b/arch/arm64/kernel/hibernate.c
@@ -299,8 +299,10 @@ int swsusp_arch_suspend(void)
dcache_clean_range(__idmap_text_start, __idmap_text_end);

/* Clean kvm setup code to PoC? */
- if (el2_reset_needed())
+ if (el2_reset_needed()) {
dcache_clean_range(__hyp_idmap_text_start, __hyp_idmap_text_end);
+ dcache_clean_range(__hyp_text_start, __hyp_text_end);
+ }

/* make the crash dump kernel image protected again */
crash_post_resume();