of: Don't allow __of_attached_node_sysfs() without CONFIG_SYSFS
Trying to boot without SYSFS, but with OF_DYNAMIC quickly
results in a crash:
[ 0.088460] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000070
[...]
[ 0.103927] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.14.0-rc3 #4179
[ 0.105810] Hardware name: linux,dummy-virt (DT)
[ 0.107147] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO BTYPE=--)
[ 0.108876] pc : kernfs_find_and_get_ns+0x3c/0x7c
[ 0.110244] lr : kernfs_find_and_get_ns+0x3c/0x7c
[...]
[ 0.134087] Call trace:
[ 0.134800] kernfs_find_and_get_ns+0x3c/0x7c
[ 0.136054] safe_name+0x4c/0xd0
[ 0.136994] __of_attach_node_sysfs+0xf8/0x124
[ 0.138287] of_core_init+0x90/0xfc
[ 0.139296] driver_init+0x30/0x4c
[ 0.140283] kernel_init_freeable+0x160/0x1b8
[ 0.141543] kernel_init+0x30/0x140
[ 0.142561] ret_from_fork+0x10/0x18
While not having sysfs isn't a very common option these days,
it is still expected that such configuration would work.
Paper over it by bailing out from __of_attach_node_sysfs() if
CONFIG_SYSFS isn't enabled.
Signed-off-by: Marc Zyngier <maz@kernel.org>
1 file changed
