diff mbox series

[PULL,17/33] target/arm: Suppress bp for exceptions with more priority

Message ID 20211215104049.2030475-18-peter.maydell@linaro.org
State Accepted
Commit 8dc89f1faa28af0df92d6c63ff249849a3e9c80e
Headers show
Series [PULL,01/33] hw/intc: clean-up error reporting for failed ITS cmd | expand

Commit Message

Peter Maydell Dec. 15, 2021, 10:40 a.m. UTC 
From: Richard Henderson <richard.henderson@linaro.org>

Both single-step and pc alignment faults have priority over
breakpoint exceptions.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/arm/debug_helper.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)
diff mbox series

Patch

diff --git a/target/arm/debug_helper.c b/target/arm/debug_helper.c
index 2983e36dd33..32f3caec238 100644
--- a/target/arm/debug_helper.c
+++ b/target/arm/debug_helper.c
@@ -220,6 +220,7 @@  bool arm_debug_check_breakpoint(CPUState *cs)
 {
     ARMCPU *cpu = ARM_CPU(cs);
     CPUARMState *env = &cpu->env;
+    target_ulong pc;
     int n;
 
     /*
@@ -231,6 +232,28 @@  bool arm_debug_check_breakpoint(CPUState *cs)
         return false;
     }
 
+    /*
+     * Single-step exceptions have priority over breakpoint exceptions.
+     * If single-step state is active-pending, suppress the bp.
+     */
+    if (arm_singlestep_active(env) && !(env->pstate & PSTATE_SS)) {
+        return false;
+    }
+
+    /*
+     * PC alignment faults have priority over breakpoint exceptions.
+     */
+    pc = is_a64(env) ? env->pc : env->regs[15];
+    if ((is_a64(env) || !env->thumb) && (pc & 3) != 0) {
+        return false;
+    }
+
+    /*
+     * Instruction aborts have priority over breakpoint exceptions.
+     * TODO: We would need to look up the page for PC and verify that
+     * it is present and executable.
+     */
+
     for (n = 0; n < ARRAY_SIZE(env->cpu_breakpoint); n++) {
         if (bp_wp_matches(cpu, n, false)) {
             return true;