[Qemu-devel] [PATCH 52/97] target/arm: Correct condition for v8M callee stack push

[Michael Roth]

From: Peter Maydell <address@hidden>

In v7m_exception_taken() we were incorrectly using a
"LR bit EXCRET.ES is 1" check when it should be 0
(compare the pseudocode ExceptionTaken() function).
This meant we didn't stack the callee-saved registers
when tailchaining from a NonSecure to a Secure exception.

Cc: address@hidden
Signed-off-by: Peter Maydell <address@hidden>
Reviewed-by: Richard Henderson <address@hidden>
Message-id: address@hidden
(cherry picked from commit 7b73a1ca05b33d42278ce29cea4652e22d408165)
Signed-off-by: Michael Roth <address@hidden>
---
 target/arm/helper.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/target/arm/helper.c b/target/arm/helper.c
index 7ee614c04f..cae2b2649d 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -6858,7 +6858,7 @@ static void v7m_exception_taken(ARMCPU *cpu, uint32_t lr, 
bool dotailchain,
                  * not already saved.
                  */
                 if (lr & R_V7M_EXCRET_DCRS_MASK &&
-                    !(dotailchain && (lr & R_V7M_EXCRET_ES_MASK))) {
+                    !(dotailchain && !(lr & R_V7M_EXCRET_ES_MASK))) {
                     push_failed = v7m_push_callee_stack(cpu, lr, dotailchain,
                                                         ignore_stackfaults);
                 }
-- 
2.17.1