diff options
author | Peter Maydell <peter.maydell@linaro.org> | 2018-03-23 15:29:48 +0000 |
---|---|---|
committer | Paolo Bonzini <pbonzini@redhat.com> | 2018-03-26 14:37:15 +0200 |
commit | 12051d82f004024d5d0202279be898c7b38cea56 (patch) | |
tree | 18ec0c1714b6b6cfb6df8f39adfd18f332f4b0d1 /chardev/char-fe.c | |
parent | 90c558beca0c0ef26db1ed77d1eb8f24a5ea02a1 (diff) |
chardev/char-fe: Allow NULL chardev in qemu_chr_fe_init()
All the functions in char-fe.c handle the CharBackend
having a NULL Chardev pointer, which means that the
backend exists but is not connected to anything. The
exception is qemu_chr_fe_init(), which will crash if
passed a NULL Chardev pointer argument. This can happen
for various boards if they're started with 'nodefaults':
arm-softmmu/qemu-system-arm -S -nodefaults -M cubieboard
riscv32-softmmu/qemu-system-riscv32 -nodefaults -M sifive_e
Make qemu_chr_fe_init() accept a NULL chardev. This allows
UART models to handle NULL chardev properties without
generally needing to special case them or to manually
create a NullChardev.
Reported-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20180323152948.27048-1-peter.maydell@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'chardev/char-fe.c')
-rw-r--r-- | chardev/char-fe.c | 22 |
1 files changed, 12 insertions, 10 deletions
diff --git a/chardev/char-fe.c b/chardev/char-fe.c index 392db78b13..b1f228e8b5 100644 --- a/chardev/char-fe.c +++ b/chardev/char-fe.c @@ -198,19 +198,21 @@ bool qemu_chr_fe_init(CharBackend *b, Chardev *s, Error **errp) { int tag = 0; - if (CHARDEV_IS_MUX(s)) { - MuxChardev *d = MUX_CHARDEV(s); + if (s) { + if (CHARDEV_IS_MUX(s)) { + MuxChardev *d = MUX_CHARDEV(s); + + if (d->mux_cnt >= MAX_MUX) { + goto unavailable; + } - if (d->mux_cnt >= MAX_MUX) { + d->backends[d->mux_cnt] = b; + tag = d->mux_cnt++; + } else if (s->be) { goto unavailable; + } else { + s->be = b; } - - d->backends[d->mux_cnt] = b; - tag = d->mux_cnt++; - } else if (s->be) { - goto unavailable; - } else { - s->be = b; } b->fe_open = false; |