From d09c4a47874f30820b08c39ad39bcca9b8cde084 Mon Sep 17 00:00:00 2001 From: Marc-André Lureau Date: Fri, 3 Nov 2017 16:28:23 +0100 Subject: chardev: fix backend events regression with mux chardev Kirill noticied that on recent versions on QEMU he was not able to trigger SysRq to invoke debug capabilites of Linux Kernel. He tracked it down to qemu_chr_be_event() ignoring CHR_EVENT_BREAK due s->be being NULL. The bug was introduced in 2.8, commit a4afa548fc6d ("char: move front end handlers in CharBackend"). Since the commit, the qemu_chr_be_event() failed to deliver CHR_EVENT_BREAK due to qemu_chr_fe_init() does not set s->be in case of mux. Let's fix this by teaching mux to send an event to the frontend with the focus. Reported-by: Kirill A. Shutemov Signed-off-by: Marc-André Lureau Fixes: a4afa548fc6d ("char: move front end handlers in CharBackend") Message-Id: <20171103152824.21948-2-marcandre.lureau@redhat.com> Tested-by: Kirill A. Shutemov Signed-off-by: Paolo Bonzini --- chardev/char.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) (limited to 'chardev/char.c') diff --git a/chardev/char.c b/chardev/char.c index 2ae4f465ec..8c3765ee99 100644 --- a/chardev/char.c +++ b/chardev/char.c @@ -43,10 +43,19 @@ static Object *get_chardevs_root(void) return container_get(object_get_root(), "/chardevs"); } -void qemu_chr_be_event(Chardev *s, int event) +static void chr_be_event(Chardev *s, int event) { CharBackend *be = s->be; + if (!be || !be->chr_event) { + return; + } + + be->chr_event(be->opaque, event); +} + +void qemu_chr_be_event(Chardev *s, int event) +{ /* Keep track if the char device is open */ switch (event) { case CHR_EVENT_OPENED: @@ -57,11 +66,7 @@ void qemu_chr_be_event(Chardev *s, int event) break; } - if (!be || !be->chr_event) { - return; - } - - be->chr_event(be->opaque, event); + CHARDEV_GET_CLASS(s)->chr_be_event(s, event); } /* Not reporting errors from writing to logfile, as logs are @@ -244,6 +249,7 @@ static void char_class_init(ObjectClass *oc, void *data) ChardevClass *cc = CHARDEV_CLASS(oc); cc->chr_write = null_chr_write; + cc->chr_be_event = chr_be_event; } static void char_finalize(Object *obj) -- cgit v1.2.3-55-g7522