hmp: Fail gracefully if chardev is already in use

Trying to attach a HMP monitor to a chardev that is already in use
results in a crash because monitor_init_hmp() passes &error_abort to
qemu_chr_fe_init():

$ ./x86_64-softmmu/qemu-system-x86_64 --chardev stdio,id=foo --mon foo --mon foo
QEMU 4.2.50 monitor - type 'help' for more information
(qemu) Unexpected error in qemu_chr_fe_init() at chardev/char-fe.c:220:
qemu-system-x86_64: --mon foo: Device 'foo' is in use
Abgebrochen (Speicherabzug geschrieben)

Fix this by allowing monitor_init_hmp() to return an error and passing
any error in qemu_chr_fe_init() to its caller instead of aborting.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200224143008.13362-19-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Kevin Wolf 2020-02-24 15:30:06 +01:00
parent f27a9bb3e9
commit 8e9119a807
7 changed files with 18 additions and 8 deletions

View file

@ -737,7 +737,13 @@ Chardev *qemu_chr_new_noreplay(const char *label, const char *filename,
if (qemu_opt_get_bool(opts, "mux", 0)) {
assert(permit_mux_mon);
monitor_init_hmp(chr, true);
monitor_init_hmp(chr, true, &err);
if (err) {
error_report_err(err);
object_unparent(OBJECT(chr));
chr = NULL;
goto out;
}
}
out: