address_space_read: address_space_to_flatview needs RCU lock
address_space_read is calling address_space_to_flatview but it can
be called outside the RCU lock. To fix it, push the rcu_read_lock/unlock
pair up from flatview_read_full to address_space_read's constant size
fast path and address_space_read_full.
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/exec.c b/exec.c
index ec91162..e4552ee 100644
--- a/exec.c
+++ b/exec.c
@@ -2616,6 +2616,8 @@
},
};
+static MemTxResult flatview_read(FlatView *fv, hwaddr addr,
+ MemTxAttrs attrs, uint8_t *buf, int len);
static MemTxResult flatview_write(FlatView *fv, hwaddr addr, MemTxAttrs attrs,
const uint8_t *buf, int len);
static bool flatview_access_valid(FlatView *fv, hwaddr addr, int len,
@@ -3165,24 +3167,18 @@
return result;
}
-MemTxResult flatview_read_full(FlatView *fv, hwaddr addr,
- MemTxAttrs attrs, uint8_t *buf, int len)
+/* Called from RCU critical section. */
+static MemTxResult flatview_read(FlatView *fv, hwaddr addr,
+ MemTxAttrs attrs, uint8_t *buf, int len)
{
hwaddr l;
hwaddr addr1;
MemoryRegion *mr;
- MemTxResult result = MEMTX_OK;
- if (len > 0) {
- rcu_read_lock();
- l = len;
- mr = flatview_translate(fv, addr, &addr1, &l, false);
- result = flatview_read_continue(fv, addr, attrs, buf, len,
- addr1, l, mr);
- rcu_read_unlock();
- }
-
- return result;
+ l = len;
+ mr = flatview_translate(fv, addr, &addr1, &l, false);
+ return flatview_read_continue(fv, addr, attrs, buf, len,
+ addr1, l, mr);
}
static MemTxResult flatview_rw(FlatView *fv, hwaddr addr, MemTxAttrs attrs,
@@ -3203,6 +3199,22 @@
addr, attrs, buf, len, is_write);
}
+MemTxResult address_space_read_full(AddressSpace *as, hwaddr addr,
+ MemTxAttrs attrs, uint8_t *buf, int len)
+{
+ MemTxResult result = MEMTX_OK;
+ FlatView *fv;
+
+ if (len > 0) {
+ rcu_read_lock();
+ fv = address_space_to_flatview(as);
+ result = flatview_read(fv, addr, attrs, buf, len);
+ rcu_read_unlock();
+ }
+
+ return result;
+}
+
MemTxResult address_space_write(AddressSpace *as, hwaddr addr,
MemTxAttrs attrs,
const uint8_t *buf, int len)