From: Michal Schmidt <mschmidt@redhat.com>
To: Rodolfo Giometti <giometti@enneenne.com>
Cc: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
"Christophe JAILLET" <christophe.jaillet@wanadoo.fr>,
"Dr. David Alan Gilbert" <linux@treblig.org>,
"Ma Ke" <make24@iscas.ac.cn>,
"Andrew Morton" <akpm@linux-foundation.org>,
"George Spelvin" <linux@horizon.com>,
linux-kernel@vger.kernel.org
Subject: [PATCH 2/6] pps: simplify pps_idr_lock locking
Date: Mon, 2 Dec 2024 17:34:47 +0100 [thread overview]
Message-ID: <20241202163451.1442566-3-mschmidt@redhat.com> (raw)
In-Reply-To: <20241202163451.1442566-1-mschmidt@redhat.com>
It is sufficient to hold pps_idr_lock only around the idr
(de)allocations. There is no reason for the assignment to pps->id or for
the error printing to be under the lock.
Simplify the pps_idr_lock locking and the error path.
Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
---
drivers/pps/pps.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c
index 4f497353daa2..9a631f6d3a1e 100644
--- a/drivers/pps/pps.c
+++ b/drivers/pps/pps.c
@@ -336,22 +336,22 @@ int pps_register_cdev(struct pps_device *pps)
int err;
dev_t devt;
- mutex_lock(&pps_idr_lock);
/*
* Get new ID for the new PPS source. After idr_alloc() calling
* the new source will be freely available into the kernel.
*/
+ mutex_lock(&pps_idr_lock);
err = idr_alloc(&pps_idr, pps, 0, PPS_MAX_SOURCES, GFP_KERNEL);
+ mutex_unlock(&pps_idr_lock);
if (err < 0) {
if (err == -ENOSPC) {
pr_err("%s: too many PPS sources in the system\n",
pps->info.name);
err = -EBUSY;
}
- goto out_unlock;
+ return err;
}
pps->id = err;
- mutex_unlock(&pps_idr_lock);
devt = MKDEV(MAJOR(pps_devt), pps->id);
@@ -389,7 +389,6 @@ int pps_register_cdev(struct pps_device *pps)
free_idr:
mutex_lock(&pps_idr_lock);
idr_remove(&pps_idr, pps->id);
-out_unlock:
mutex_unlock(&pps_idr_lock);
return err;
}
--
2.47.0
next prev parent reply other threads:[~2024-12-02 16:35 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-12-02 16:34 [PATCH 0/6] pps: fix a UAF and clean up code Michal Schmidt
2024-12-02 16:34 ` [PATCH 1/6] pps: fix cdev use-after-free Michal Schmidt
2024-12-02 16:34 ` Michal Schmidt [this message]
2024-12-02 16:34 ` [PATCH 3/6] pps: use scoped_guard for pps_idr_lock Michal Schmidt
2024-12-03 9:06 ` Uwe Kleine-König
2024-12-02 16:34 ` [PATCH 4/6] pps: print error in both cdev and dev error paths in pps_register_cdev() Michal Schmidt
2024-12-02 16:34 ` [PATCH 5/6] pps: embed "dev" in the pps_device Michal Schmidt
2024-12-03 1:02 ` kernel test robot
2024-12-03 2:04 ` kernel test robot
2024-12-02 16:34 ` [PATCH 6/6] pps: use cdev_device_add() Michal Schmidt
2024-12-02 16:56 ` [PATCH 0/6] pps: fix a UAF and clean up code Calvin Owens
2024-12-02 17:58 ` Michal Schmidt
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