Hi Vikram,
On 19/08/2023 01:28, Vikram Garhwal wrote:
This will be useful in dynamic node programming when new dt nodes are unflattend
during runtime. Invalid device tree node related errors should be propagated
back to the caller.
Signed-off-by: Vikram Garhwal
---
Changes from v7:
Free allocated memory in case of errors when calling unflatten_dt_node.
---
---
xen/common/device_tree.c | 17 +++--
1 file changed, 15 insertions(+), 2 deletions(-)
diff --git a/xen/common/device_tree.c b/xen/common/device_tree.c
index c91d54c493..cd9a6a5c93 100644
--- a/xen/common/device_tree.c
+++ b/xen/common/device_tree.c
@@ -2108,6 +2108,9 @@ static int __init __unflatten_device_tree(const void *fdt,
/* First pass, scan for size */
start = ((unsigned long)fdt) + fdt_off_dt_struct(fdt);
size = unflatten_dt_node(fdt, 0, , NULL, NULL, 0);
+if ( !size )
+return -EINVAL;
+
size = (size | 3) + 1;
dt_dprintk(" size is %#lx allocating...\n", size);
@@ -2125,11 +2128,21 @@ static int __init __unflatten_device_tree(const void
*fdt,
start = ((unsigned long)fdt) + fdt_off_dt_struct(fdt);
unflatten_dt_node(fdt, mem, , NULL, , 0);
if ( be32_to_cpup((__be32 *)start) != FDT_END )
-printk(XENLOG_WARNING "Weird tag at end of tree: %08x\n",
+{
+printk(XENLOG_ERR "Weird tag at end of tree: %08x\n",
*((u32 *)start));
+xfree((__be64 *)mem);
I know that 'mem' is an 'unsigned long' so you need to cast it to a
pointer. But '__be64 *' seems a rather odd choice. Why not using 'void *'?
Better would be to convert 'mem' to a 'void *' as we allow pointer
arithmetic in Xen. But that can be dealt separately.
+return -EINVAL;
+}
+
if ( be32_to_cpu(((__be32 *)mem)[size / 4]) != 0xdeadbeefU )
-printk(XENLOG_WARNING "End of tree marker overwritten: %08x\n",
+{
+printk(XENLOG_ERR "End of tree marker overwritten: %08x\n",
be32_to_cpu(((__be32 *)mem)[size / 4]));
+xfree((__be64 *)mem);
Same remark here.
+return -EINVAL;
+}
+
*allnextp = NULL;
dt_dprintk(" <- unflatten_device_tree()\n");
Cheers,
--
Julien Grall
