@@ -55,6 +55,9 @@ int qemu_bh_poll(void)
{
QEMUBH *bh, **bhp, *next;
int ret;
+ static int nesting = 0;
+
+ nesting++;
ret = 0;
for (bh = first_bh; bh; bh = next) {
@@ -68,15 +71,20 @@ int qemu_bh_poll(void)
}
}
+ nesting--;
+
/* remove deleted bhs */
- bhp = &first_bh;
- while (*bhp) {
- bh = *bhp;
- if (bh->deleted) {
- *bhp = bh->next;
- g_free(bh);
- } else
- bhp = &bh->next;
+ if (!nesting) {
+ bhp = &first_bh;
+ while (*bhp) {
+ bh = *bhp;
+ if (bh->deleted) {
+ *bhp = bh->next;
+ g_free(bh);
+ } else {
+ bhp = &bh->next;
+ }
+ }
}
return ret;
qemu may segfault when a BH handler first deletes a BH and then (possibly indirectly) calls a nested qemu_bh_poll(). This is because the inner instance frees the BH and deletes it from the list that the outer one processes. This patch deletes BHs only in the outermost qemu_bh_poll instance. Commit 7887f620 already tried to achieve the same, but it assumed that the BH handler would only delete its own BH. With a nested qemu_bh_poll(), this isn't guaranteed, so that commit wasn't enough. Hope this one fixes it for real. Signed-off-by: Kevin Wolf <kwolf@redhat.com> --- async.c | 24 ++++++++++++++++-------- 1 files changed, 16 insertions(+), 8 deletions(-)