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authorPeter Maydell <peter.maydell@linaro.org>2018-03-23 15:29:48 +0000
committerPaolo Bonzini <pbonzini@redhat.com>2018-03-26 14:37:15 +0200
commit12051d82f004024d5d0202279be898c7b38cea56 (patch)
tree18ec0c1714b6b6cfb6df8f39adfd18f332f4b0d1 /chardev/char-fe.c
parent90c558beca0c0ef26db1ed77d1eb8f24a5ea02a1 (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.c22
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;