[PATCH for 6.2 48/49] bsd-user: Implement cpu_copy() helper routine

[Warner Losh]

From: Warner Losh <imp@FreeBSD.org>

cpu_copy shouldbe called when processes are creating new threads. It
copies the current state of the CPU to a new cpu state needed for the
new thread.

Signed-off-by: Stacey Son <sson@FreeBSD.org>
Signed-off-by: Warner Losh <imp@bsdimp.com>
Signed-off-by: Justin Hibbits <chmeeedalf@gmail.com>
---
 bsd-user/main.c | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/bsd-user/main.c b/bsd-user/main.c
index 2b0716d245..1de5dc189b 100644
--- a/bsd-user/main.c
+++ b/bsd-user/main.c
@@ -196,6 +196,36 @@ void init_task_state(TaskState *ts)
     ts->sigqueue_table[i].next = NULL;
 }
 
+CPUArchState *cpu_copy(CPUArchState *env)
+{
+    CPUState *cpu = env_cpu(env);
+    CPUState *new_cpu = cpu_create(cpu_type);
+    CPUArchState *new_env = new_cpu->env_ptr;
+    CPUBreakpoint *bp;
+    CPUWatchpoint *wp;
+
+    /* Reset non arch specific state */
+    cpu_reset(new_cpu);
+
+    memcpy(new_env, env, sizeof(CPUArchState));
+
+    /*
+     * Clone all break/watchpoints.
+     * Note: Once we support ptrace with hw-debug register access, make sure
+     * BP_CPU break/watchpoints are handled correctly on clone.
+     */
+    QTAILQ_INIT(&cpu->breakpoints);
+    QTAILQ_INIT(&cpu->watchpoints);
+    QTAILQ_FOREACH(bp, &cpu->breakpoints, entry) {
+        cpu_breakpoint_insert(new_cpu, bp->pc, bp->flags, NULL);
+    }
+    QTAILQ_FOREACH(wp, &cpu->watchpoints, entry) {
+        cpu_watchpoint_insert(new_cpu, wp->vaddr, wp->len, wp->flags, NULL);
+    }
+
+    return new_env;
+}
+
 void gemu_log(const char *fmt, ...)
 {
     va_list ap;
-- 
2.32.0