From: Anton Ivanov <anton.ivanov@xxxxxxxxxxxxxxxxxx> commit 1a3a6a2a035bb6c3a7ef4c788d8fd69a7b2d6284 upstream. Moving to an EPOLL based IRQ controller broke uml_mconsole stop/go commands. This fixes it and restores stop/go functionality. Fixes: ff6a17989c08 ("Epoll based IRQ controller") Signed-off-by: Anton Ivanov <anton.ivanov@xxxxxxxxxxxxxxxxxx> Signed-off-by: Richard Weinberger <richard@xxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/um/drivers/mconsole_kern.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/arch/um/drivers/mconsole_kern.c +++ b/arch/um/drivers/mconsole_kern.c @@ -218,7 +218,7 @@ void mconsole_go(struct mc_request *req) void mconsole_stop(struct mc_request *req) { - deactivate_fd(req->originating_fd, MCONSOLE_IRQ); + block_signals(); os_set_fd_block(req->originating_fd, 1); mconsole_reply(req, "stopped", 0, 0); for (;;) { @@ -242,6 +242,7 @@ void mconsole_stop(struct mc_request *re os_set_fd_block(req->originating_fd, 0); reactivate_fd(req->originating_fd, MCONSOLE_IRQ); mconsole_reply(req, "", 0, 0); + unblock_signals(); } static DEFINE_SPINLOCK(mc_devices_lock); Patches currently in stable-queue which might be from anton.ivanov@xxxxxxxxxxxxxxxxxx are queue-4.19/um-fix-uml_mconsole-stop-go.patch