clear-pkgs-linux-iot-lts2018/0934-check-return-value-of-hypercall.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: "Zhang, Qi" <qi1.zhang@intel.com>
Date: Thu, 16 Aug 2018 18:04:44 +0800
Subject: [PATCH] check return value of hypercall

exit from probe if acrn does not enable trusty

Change-Id: I99271cd96c6df46e141b4e57a2af378119a1c25c
Tracked-On: OAM-67637
Signed-off-by: Zhang, Qi <qi1.zhang@intel.com>
---
 drivers/trusty/trusty.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/trusty/trusty.c b/drivers/trusty/trusty.c
index f37a1a58dce8..881924f88e4f 100755
--- a/drivers/trusty/trusty.c
+++ b/drivers/trusty/trusty.c
@@ -72,13 +72,18 @@ static inline ulong smc_evmm(ulong r0, ulong r1, ulong r2, ulong r3)
 static inline ulong smc_acrn(ulong r0, ulong r1, ulong r2, ulong r3)
 {
 	register unsigned long smc_id asm("r8") = ACRN_HC_SWITCH_WORLD;
+	register signed long ret asm("rax");
 	__asm__ __volatile__(
 		"vmcall; \n"
-		: "=D"(r0)
+		: "=D"(r0), "=r"(ret)
 		: "r"(smc_id), "D"(r0), "S"(r1), "d"(r2), "b"(r3)
-		: "rax"
 	);
 
+	if(ret < 0) {
+		pr_err("trusty: %s: hypercall failed: %ld\n", __func__, ret);
+		r0 = (ulong)SM_ERR_NOT_SUPPORTED;
+	}
+
 	return r0;
 }
 
-- 
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