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authorAlex Bennée <alex.bennee@linaro.org>2018-11-13 10:47:59 +0000
committerPeter Maydell <peter.maydell@linaro.org>2018-11-13 10:47:59 +0000
commit22af90255ec2100a44cbbb7f0460ba15eed79538 (patch)
treeb74ca29cb0a41c0d3b899aad83c239857ae9b344
parentb281ba4223c302c41ff8104152bfdd44de4fe798 (diff)
arm: fix aa64_generate_debug_exceptions to work with EL2
The test was incomplete and incorrectly caused debug exceptions to be generated when returning to EL2 after a failed attempt to single-step an EL1 instruction. Fix this while cleaning up the function a little. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20181109152119.9242-8-alex.bennee@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
-rw-r--r--target/arm/cpu.h39
1 files changed, 24 insertions, 15 deletions
diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index 1efff21a18..814ff69bc2 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -2764,23 +2764,35 @@ static inline bool arm_v7m_csselr_razwi(ARMCPU *cpu)
return (cpu->clidr & R_V7M_CLIDR_CTYPE_ALL_MASK) != 0;
}
+/* See AArch64.GenerateDebugExceptionsFrom() in ARM ARM pseudocode */
static inline bool aa64_generate_debug_exceptions(CPUARMState *env)
{
- if (arm_is_secure(env)) {
- /* MDCR_EL3.SDD disables debug events from Secure state */
- if (extract32(env->cp15.mdcr_el3, 16, 1) != 0
- || arm_current_el(env) == 3) {
- return false;
- }
+ int cur_el = arm_current_el(env);
+ int debug_el;
+
+ if (cur_el == 3) {
+ return false;
}
- if (arm_current_el(env) == arm_debug_target_el(env)) {
- if ((extract32(env->cp15.mdscr_el1, 13, 1) == 0)
- || (env->daif & PSTATE_D)) {
- return false;
- }
+ /* MDCR_EL3.SDD disables debug events from Secure state */
+ if (arm_is_secure_below_el3(env)
+ && extract32(env->cp15.mdcr_el3, 16, 1)) {
+ return false;
}
- return true;
+
+ /*
+ * Same EL to same EL debug exceptions need MDSCR_KDE enabled
+ * while not masking the (D)ebug bit in DAIF.
+ */
+ debug_el = arm_debug_target_el(env);
+
+ if (cur_el == debug_el) {
+ return extract32(env->cp15.mdscr_el1, 13, 1)
+ && !(env->daif & PSTATE_D);
+ }
+
+ /* Otherwise the debug target needs to be a higher EL */
+ return debug_el > cur_el;
}
static inline bool aa32_generate_debug_exceptions(CPUARMState *env)
@@ -2833,9 +2845,6 @@ static inline bool aa32_generate_debug_exceptions(CPUARMState *env)
* since the pseudocode has it at all callsites except for the one in
* CheckSoftwareStep(), where it is elided because both branches would
* always return the same value.
- *
- * Parts of the pseudocode relating to EL2 and EL3 are omitted because we
- * don't yet implement those exception levels or their associated trap bits.
*/
static inline bool arm_generate_debug_exceptions(CPUARMState *env)
{