From: bumwoo lee <bw365.lee@samsung.com>
To: MyungJoo Ham <myungjoo.ham@samsung.com>,
Chanwoo Choi <cw00.choi@samsung.com>,
linux-kernel@vger.kernel.org
Cc: bumwoo lee <bw365.lee@samsung.com>
Subject: [PATCH V1] extcon: modify extcon device to be created after driver data is set
Date: Wed, 27 Apr 2022 12:00:05 +0900 [thread overview]
Message-ID: <20220427030005.706-1-bw365.lee@samsung.com> (raw)
In-Reply-To: CGME20220427030050epcas1p377eb744ed82b0e4a80747da6229fedca@epcas1p3.samsung.com
Currently, someone can invoke the sysfs such as state_show()
intermittently before dev_set_drvdata() is done.
And it can be a cause of kernel Oops because of edev is Null at that time.
So modified the driver registration to after setting drviver data.
- Oops's backtrace.
Backtrace:
[<c067865c>] (state_show) from [<c05222e8>] (dev_attr_show)
[<c05222c0>] (dev_attr_show) from [<c02c66e0>] (sysfs_kf_seq_show)
[<c02c6648>] (sysfs_kf_seq_show) from [<c02c496c>] (kernfs_seq_show)
[<c02c4938>] (kernfs_seq_show) from [<c025e2a0>] (seq_read)
[<c025e11c>] (seq_read) from [<c02c50a0>] (kernfs_fop_read)
[<c02c5064>] (kernfs_fop_read) from [<c0231cac>] (__vfs_read)
[<c0231c5c>] (__vfs_read) from [<c0231ee0>] (vfs_read)
[<c0231e34>] (vfs_read) from [<c0232464>] (ksys_read)
[<c02323f0>] (ksys_read) from [<c02324fc>] (sys_read)
[<c02324e4>] (sys_read) from [<c00091d0>] (__sys_trace_return)
Signed-off-by: bumwoo lee <bw365.lee@samsung.com>
---
drivers/extcon/extcon.c | 29 +++++++++++++++++------------
1 file changed, 17 insertions(+), 12 deletions(-)
diff --git a/drivers/extcon/extcon.c b/drivers/extcon/extcon.c
index d27cd9f88f86..d3a32b806499 100644
--- a/drivers/extcon/extcon.c
+++ b/drivers/extcon/extcon.c
@@ -1224,19 +1224,14 @@ int extcon_dev_register(struct extcon_dev *edev)
edev->dev.type = &edev->extcon_dev_type;
}
- ret = device_register(&edev->dev);
- if (ret) {
- put_device(&edev->dev);
- goto err_dev;
- }
-
spin_lock_init(&edev->lock);
- edev->nh = devm_kcalloc(&edev->dev, edev->max_supported,
- sizeof(*edev->nh), GFP_KERNEL);
- if (!edev->nh) {
- ret = -ENOMEM;
- device_unregister(&edev->dev);
- goto err_dev;
+ if (edev->max_supported) {
+ edev->nh = kcalloc(edev->max_supported, sizeof(*edev->nh),
+ GFP_KERNEL);
+ if (!edev->nh) {
+ ret = -ENOMEM;
+ goto err_alloc_nh;
+ }
}
for (index = 0; index < edev->max_supported; index++)
@@ -1247,6 +1242,12 @@ int extcon_dev_register(struct extcon_dev *edev)
dev_set_drvdata(&edev->dev, edev);
edev->state = 0;
+ ret = device_register(&edev->dev);
+ if (ret) {
+ put_device(&edev->dev);
+ goto err_dev;
+ }
+
mutex_lock(&extcon_dev_list_lock);
list_add(&edev->entry, &extcon_dev_list);
mutex_unlock(&extcon_dev_list_lock);
@@ -1254,6 +1255,9 @@ int extcon_dev_register(struct extcon_dev *edev)
return 0;
err_dev:
+ if (edev->max_supported)
+ kfree(edev->nh);
+err_alloc_nh:
if (edev->max_supported)
kfree(edev->extcon_dev_type.groups);
err_alloc_groups:
@@ -1314,6 +1318,7 @@ void extcon_dev_unregister(struct extcon_dev *edev)
if (edev->max_supported) {
kfree(edev->extcon_dev_type.groups);
kfree(edev->cables);
+ kfree(edev->nh);
}
put_device(&edev->dev);
--
2.35.1
next parent reply other threads:[~2022-04-27 3:01 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20220427030050epcas1p377eb744ed82b0e4a80747da6229fedca@epcas1p3.samsung.com>
2022-04-27 3:00 ` bumwoo lee [this message]
2022-04-27 23:16 ` [PATCH V1] extcon: modify extcon device to be created after driver data is set Chanwoo Choi
2022-04-28 0:36 ` Bumwoo Lee
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20220427030005.706-1-bw365.lee@samsung.com \
--to=bw365.lee@samsung.com \
--cc=cw00.choi@samsung.com \
--cc=linux-kernel@vger.kernel.org \
--cc=myungjoo.ham@samsung.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).