diff options
| author | Tyrel Datwyler <tyreld@linux.vnet.ibm.com> | 2017-09-20 17:02:51 -0400 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2017-09-21 19:30:53 +1000 |
| commit | 087ff6a5ae3052bb2835e191094b793789cb8817 (patch) | |
| tree | b9a3e155e425dea146800180e36c964dc57ec30d | |
| parent | 3e77adeea3c5393c9b624832f65441e92867f618 (diff) | |
powerpc/pseries: Fix "OF: ERROR: Bad of_node_put() on /cpus" during DLPAR
Commit 215ee763f8cb ("powerpc: pseries: remove dlpar_attach_node
dependency on full path") reworked dlpar_attach_node() to no longer
look up the parent node "/cpus", but instead to have the parent node
passed by the caller in the function parameter list.
As a result dlpar_attach_node() is no longer responsible for freeing
the reference to the parent node. However, commit 215ee763f8cb failed
to remove the of_node_put(parent) call in dlpar_attach_node(), or to
take into account that the reference to the parent in the caller
dlpar_cpu_add() needs to be held until after dlpar_attach_node()
returns.
As a result doing repeated cpu add/remove dlpar operations will
eventually result in the following error:
OF: ERROR: Bad of_node_put() on /cpus
CPU: 0 PID: 10896 Comm: drmgr Not tainted 4.13.0-autotest #1
Call Trace:
dump_stack+0x15c/0x1f8 (unreliable)
of_node_release+0x1a4/0x1c0
kobject_put+0x1a8/0x310
kobject_del+0xbc/0xf0
__of_detach_node_sysfs+0x144/0x210
of_detach_node+0xf0/0x180
dlpar_detach_node+0xc4/0x120
dlpar_cpu_remove+0x280/0x560
dlpar_cpu_release+0xbc/0x1b0
arch_cpu_release+0x6c/0xb0
cpu_release_store+0xa0/0x100
dev_attr_store+0x68/0xa0
sysfs_kf_write+0xa8/0xf0
kernfs_fop_write+0x2cc/0x400
__vfs_write+0x5c/0x340
vfs_write+0x1a8/0x3d0
SyS_write+0xa8/0x1a0
system_call+0x58/0x6c
Fix the issue by removing the of_node_put(parent) call from
dlpar_attach_node(), and ensuring that the reference to the parent
node is properly held and released by the caller dlpar_cpu_add().
Fixes: 215ee763f8cb ("powerpc: pseries: remove dlpar_attach_node dependency on full path")
Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Reported-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
[mpe: Add a comment in the code and frob the change log slightly]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| -rw-r--r-- | arch/powerpc/platforms/pseries/dlpar.c | 1 | ||||
| -rw-r--r-- | arch/powerpc/platforms/pseries/hotplug-cpu.c | 6 |
2 files changed, 5 insertions, 2 deletions
diff --git a/arch/powerpc/platforms/pseries/dlpar.c b/arch/powerpc/platforms/pseries/dlpar.c index 783f36364690..e45b5f10645a 100644 --- a/arch/powerpc/platforms/pseries/dlpar.c +++ b/arch/powerpc/platforms/pseries/dlpar.c @@ -266,7 +266,6 @@ int dlpar_attach_node(struct device_node *dn, struct device_node *parent) return rc; } - of_node_put(dn->parent); return 0; } diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c index fc0d8f97c03a..fadb95efbb9e 100644 --- a/arch/powerpc/platforms/pseries/hotplug-cpu.c +++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c @@ -462,15 +462,19 @@ static ssize_t dlpar_cpu_add(u32 drc_index) } dn = dlpar_configure_connector(cpu_to_be32(drc_index), parent); - of_node_put(parent); if (!dn) { pr_warn("Failed call to configure-connector, drc index: %x\n", drc_index); dlpar_release_drc(drc_index); + of_node_put(parent); return -EINVAL; } rc = dlpar_attach_node(dn, parent); + + /* Regardless we are done with parent now */ + of_node_put(parent); + if (rc) { saved_rc = rc; pr_warn("Failed to attach node %s, rc: %d, drc index: %x\n", |