From e4e839b2eeea5745c48ce47144c7842eb7cd455f Mon Sep 17 00:00:00 2001 From: Geoffrey Thomas Date: Fri, 14 Mar 2025 08:47:42 -0400 Subject: linux-user: Hold the fd-trans lock across fork If another thread is holding target_fd_trans_lock during a fork, then the lock becomes permanently locked in the child and the emulator deadlocks at the next interaction with the fd-trans table. As with other locks, acquire the lock in fork_start() and release it in fork_end(). Cc: qemu-stable@nongnu.org Signed-off-by: Geoffrey Thomas Fixes: c093364f4d91 "fd-trans: Fix race condition on reallocation of the translation table." Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2846 Buglink: https://github.com/astral-sh/uv/issues/6105 Reviewed-by: Richard Henderson Signed-off-by: Richard Henderson Message-ID: <20250314124742.4965-1-geofft@ldpreload.com> --- linux-user/main.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'linux-user/main.c') diff --git a/linux-user/main.c b/linux-user/main.c index a9142ee726..f4f2007439 100644 --- a/linux-user/main.c +++ b/linux-user/main.c @@ -149,12 +149,14 @@ void fork_start(void) cpu_list_lock(); qemu_plugin_user_prefork_lock(); gdbserver_fork_start(); + fd_trans_prefork(); } void fork_end(pid_t pid) { bool child = pid == 0; + fd_trans_postfork(); qemu_plugin_user_postfork(child); mmap_fork_end(child); if (child) { -- cgit 1.4.1