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>
master
Alex Bennée 2018-11-13 10:47:59 +00:00 committed by Peter Maydell
parent b281ba4223
commit 22af90255e
1 changed files with 24 additions and 15 deletions

View File

@ -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)
{