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>
Link: https://lore.kernel.org/r/20210820144722.169226-1-maz@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
The problem in this code is that if kobject_add() fails, then it should
call of_node_put(np) to drop the reference count. I've actually moved
the of_node_get(np) later in the function to avoid needing to do clean
up.
Fixes: 5b2c2f5a0e ("of: overlay: add missing of_node_get() in __of_attach_node_sysfs")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Rob Herring <robh@kernel.org>
There is a matching of_node_put() in __of_detach_node_sysfs()
Remove misleading comment from function header comment for
of_detach_node().
This patch may result in memory leaks from code that directly calls
the dynamic node add and delete functions directly instead of
using changesets.
This commit should result in powerpc systems that dynamically
allocate a node, then later deallocate the node to have a
memory leak when the node is deallocated.
The next commit will fix the leak.
Tested-by: Alan Tull <atull@kernel.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Having device_nodes be kobjects is only needed if sysfs or OF_DYNAMIC is
enabled. Otherwise, having a kobject in struct device_node is
unnecessary bloat in minimal kernel configurations.
Likewise, bin_attribute is only needed in struct property when sysfs is
enabled, so we can make it configurable too.
Tested-by: Nicolas Pitre <nico@linaro.org>
Reviewed-by: Frank Rowand <frowand.list@gmail.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Rob Herring <robh@kernel.org>
Marc Zyngier