device property: fwnode->secondary may contain ERR_PTR(-ENODEV)

This fixes BUG triggered when fwnode->secondary is not NULL,
but has ERR_PTR(-ENODEV) instead.

BUG: unable to handle kernel paging request at ffffffffffffffed
IP: [<ffffffff81677b86>] __fwnode_property_read_string+0x26/0x160
PGD 200e067 PUD 2010067 PMD 0
Oops: 0000 [#1] SMP KASAN
Modules linked in: dwc3_pci(+) dwc3
CPU: 0 PID: 1138 Comm: modprobe Not tainted 4.5.0-rc5+ #61
task: ffff88015aaf5b00 ti: ffff88007b958000 task.ti: ffff88007b958000
RIP: 0010:[<ffffffff81677b86>]  [<ffffffff81677b86>] __fwnode_property_read_string+0x26/0x160
RSP: 0018:ffff88007b95eff8  EFLAGS: 00010246
RAX: fffffbfffffffffd RBX: ffffffffffffffed RCX: ffff88015999cd37
RDX: dffffc0000000000 RSI: ffffffff81e11bc0 RDI: ffffffffffffffed
RBP: ffff88007b95f020 R08: 0000000000000000 R09: 0000000000000000
R10: ffff88007b90f7cf R11: 0000000000000000 R12: ffff88007b95f0a0
R13: 00000000fffffffa R14: ffffffff81e11bc0 R15: ffff880159ea37a0
FS:  00007ff35f46c700(0000) GS:ffff88015b800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: ffffffffffffffed CR3: 000000007b8be000 CR4: 00000000001006f0
Stack:
 ffff88015999cd20 ffffffff81e11bc0 ffff88007b95f0a0 ffff88007b383dd8
 ffff880159ea37a0 ffff88007b95f048 ffffffff81677d03 ffff88007b952460
 ffffffff81e11bc0 ffff88007b95f0a0 ffff88007b95f070 ffffffff81677d40
Call Trace:
 [<ffffffff81677d03>] fwnode_property_read_string+0x43/0x50
 [<ffffffff81677d40>] device_property_read_string+0x30/0x40
...

Fixes: 362c0b30249e (device property: Fallback to secondary fwnode if primary misses the property)
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/base/property.c b/drivers/base/property.c
index c359351d50f1c99e9758b74ea84d97e76b402b0f..a163f2c59aa36571359e75661d52cfdc55d4ef3b 100644 (file)
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -218,7 +218,7 @@ bool fwnode_property_present(struct fwnode_handle *fwnode, const char *propname)
        bool ret;
 
        ret = __fwnode_property_present(fwnode, propname);
-       if (ret == false && fwnode && fwnode->secondary)
+       if (ret == false && fwnode && !IS_ERR_OR_NULL(fwnode->secondary))
                ret = __fwnode_property_present(fwnode->secondary, propname);
        return ret;
 }
@@ -423,7 +423,7 @@ EXPORT_SYMBOL_GPL(device_property_match_string);
        int _ret_;                                                                      \
        _ret_ = FWNODE_PROP_READ(_fwnode_, _propname_, _type_, _proptype_,              \
                                 _val_, _nval_);                                        \
-       if (_ret_ == -EINVAL && _fwnode_ && _fwnode_->secondary)                        \
+       if (_ret_ == -EINVAL && _fwnode_ && !IS_ERR_OR_NULL(_fwnode_->secondary))       \
                _ret_ = FWNODE_PROP_READ(_fwnode_->secondary, _propname_, _type_,       \
                                _proptype_, _val_, _nval_);                             \
        _ret_;                                                                          \
@@ -593,7 +593,7 @@ int fwnode_property_read_string_array(struct fwnode_handle *fwnode,
        int ret;
 
        ret = __fwnode_property_read_string_array(fwnode, propname, val, nval);
-       if (ret == -EINVAL && fwnode && fwnode->secondary)
+       if (ret == -EINVAL && fwnode && !IS_ERR_OR_NULL(fwnode->secondary))
                ret = __fwnode_property_read_string_array(fwnode->secondary,
                                                          propname, val, nval);
        return ret;
@@ -621,7 +621,7 @@ int fwnode_property_read_string(struct fwnode_handle *fwnode,
        int ret;
 
        ret = __fwnode_property_read_string(fwnode, propname, val);
-       if (ret == -EINVAL && fwnode && fwnode->secondary)
+       if (ret == -EINVAL && fwnode && !IS_ERR_OR_NULL(fwnode->secondary))
                ret = __fwnode_property_read_string(fwnode->secondary,
                                                    propname, val);
        return ret;