bsd-user: Sync fork_start/fork_end with linux-user

This reorders some of the calls, deduplicates code between branches and,
most importantly, fixes a double end_exclusive call in the parent that
will cause exclusive_context_count to go negative.

Signed-off-by: Jessica Clarke <jrtc27@jrtc27.com>
Pull-Request: https://github.com/qemu-bsd-user/qemu-bsd-user/pull/52
Reviewed-by: Warner Losh <imp@bsdimp.com>
Signed-off-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Jessica Clarke 2024-06-19 20:03:44 +01:00 committed by Warner Losh
parent b314fd06cf
commit 5b6828d194

View file

@ -35,6 +35,7 @@
#include "qemu/path.h"
#include "qemu/help_option.h"
#include "qemu/module.h"
#include "qemu/plugin.h"
#include "exec/exec-all.h"
#include "user/guest-base.h"
#include "tcg/startup.h"
@ -103,8 +104,9 @@ unsigned long target_sgrowsiz = TARGET_SGROWSIZ; /* amount to grow stack */
void fork_start(void)
{
start_exclusive();
cpu_list_lock();
mmap_fork_start();
cpu_list_lock();
qemu_plugin_user_prefork_lock();
gdbserver_fork_start();
}
@ -112,31 +114,31 @@ void fork_end(pid_t pid)
{
bool child = pid == 0;
qemu_plugin_user_postfork(child);
mmap_fork_end(child);
if (child) {
CPUState *cpu, *next_cpu;
/*
* Child processes created by fork() only have a single thread. Discard
* information about the parent threads.
* Child processes created by fork() only have a single thread.
* Discard information about the parent threads.
*/
CPU_FOREACH_SAFE(cpu, next_cpu) {
if (cpu != thread_cpu) {
QTAILQ_REMOVE_RCU(&cpus_queue, cpu, node);
}
}
mmap_fork_end(child);
/*
* qemu_init_cpu_list() takes care of reinitializing the exclusive
* state, so we don't need to end_exclusive() here.
*/
qemu_init_cpu_list();
get_task_state(thread_cpu)->ts_tid = qemu_get_thread_id();
gdbserver_fork_end(thread_cpu, pid);
} else {
mmap_fork_end(child);
cpu_list_unlock();
gdbserver_fork_end(thread_cpu, pid);
end_exclusive();
}
gdbserver_fork_end(thread_cpu, pid);
/*
* qemu_init_cpu_list() reinitialized the child exclusive state, but we
* also need to keep current_cpu consistent, so call end_exclusive() for
* both child and parent.
*/
end_exclusive();
}
void cpu_loop(CPUArchState *env)