target/riscv: Allocate itrigger timers only once

riscv_trigger_init() had been called on reset events that can happen
several times for a CPU and it allocated timers for itrigger. If old
timers were present, they were simply overwritten by the new timers,
resulting in a memory leak.

Divide riscv_trigger_init() into two functions, namely
riscv_trigger_realize() and riscv_trigger_reset() and call them in
appropriate timing. The timer allocation will happen only once for a
CPU in riscv_trigger_realize().

Fixes: 5a4ae64cac ("target/riscv: Add itrigger support when icount is enabled")
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20230818034059.9146-1-akihiko.odaki@daynix.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
(cherry picked from commit a7c272df82)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

target/riscv/cpu.c

@@ -916,7 +916,7 @@ static void riscv_cpu_reset_hold(Object *obj)
 
 #ifndef CONFIG_USER_ONLY
     if (cpu->cfg.debug) {
-        riscv_trigger_init(env);
+        riscv_trigger_reset_hold(env);
     }
 
     if (kvm_enabled()) {
@@ -1491,6 +1491,12 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
 
     riscv_cpu_register_gdb_regs_for_features(cs);
 
+#ifndef CONFIG_USER_ONLY
+    if (cpu->cfg.debug) {
+        riscv_trigger_realize(&cpu->env);
+    }
+#endif
+
     qemu_init_vcpu(cs);
     cpu_reset(cs);
 

target/riscv/debug.c

@@ -903,7 +903,17 @@ bool riscv_cpu_debug_check_watchpoint(CPUState *cs, CPUWatchpoint *wp)
     return false;
 }
 
-void riscv_trigger_init(CPURISCVState *env)
+void riscv_trigger_realize(CPURISCVState *env)
+{
+    int i;
+
+    for (i = 0; i < RV_MAX_TRIGGERS; i++) {
+        env->itrigger_timer[i] = timer_new_ns(QEMU_CLOCK_VIRTUAL,
+                                              riscv_itrigger_timer_cb, env);
+    }
+}
+
+void riscv_trigger_reset_hold(CPURISCVState *env)
 {
     target_ulong tdata1 = build_tdata1(env, TRIGGER_TYPE_AD_MATCH, 0, 0);
     int i;
@@ -928,7 +938,6 @@ void riscv_trigger_init(CPURISCVState *env)
         env->tdata3[i] = 0;
         env->cpu_breakpoint[i] = NULL;
         env->cpu_watchpoint[i] = NULL;
-        env->itrigger_timer[i] = timer_new_ns(QEMU_CLOCK_VIRTUAL,
-                                              riscv_itrigger_timer_cb, env);
+        timer_del(env->itrigger_timer[i]);
     }
 }

target/riscv/debug.h

@@ -143,7 +143,8 @@ void riscv_cpu_debug_excp_handler(CPUState *cs);
 bool riscv_cpu_debug_check_breakpoint(CPUState *cs);
 bool riscv_cpu_debug_check_watchpoint(CPUState *cs, CPUWatchpoint *wp);
 
-void riscv_trigger_init(CPURISCVState *env);
+void riscv_trigger_realize(CPURISCVState *env);
+void riscv_trigger_reset_hold(CPURISCVState *env);
 
 bool riscv_itrigger_enabled(CPURISCVState *env);
 void riscv_itrigger_update_priv(CPURISCVState *env);