[PATCH 5.7 092/265] IB/hfi1: Fix module use count flaw due to leftover module put calls

Sasha Levin
2020-06-29T21:58:59Z

From: Dennis Dalessandro <dennis.dalessandro@intel.com>

commit 822fbd37410639acdae368ea55477ddd3498651d upstream.

When the try_module_get calls were removed from opening and closing of the
i2c debugfs file, the corresponding module_put calls were missed. This
results in an inaccurate module use count that requires a power cycle to
fix.

Fixes: 09fbca8e6240 ("IB/hfi1: No need to use try_module_get for debugfs")
Link: https://lore.kernel.org/r/20200623203230.106975.76240.stgit@awfm-01.aw.intel.com
Cc: <stable@vger.kernel.org>
Reviewed-by: Kaike Wan <kaike.wan@intel.com>
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/infiniband/hw/hfi1/debugfs.c | 19 ++-----------------
1 file changed, 2 insertions(+), 17 deletions(-)

diff --git a/drivers/infiniband/hw/hfi1/debugfs.c b/drivers/infiniband/hw/hfi1/debugfs.c
index 4633a0ce1a8c0..2ced236e1553c 100644
--- a/drivers/infiniband/hw/hfi1/debugfs.c
+++ b/drivers/infiniband/hw/hfi1/debugfs.c
@@ -985,15 +985,10 @@ static ssize_t qsfp2_debugfs_read(struct file *file, char __user *buf,
static int __i2c_debugfs_open(struct inode *in, struct file *fp, u32 target)
{
struct hfi1_pportdata *ppd;
- int ret;

ppd = private2ppd(fp);

- ret = acquire_chip_resource(ppd->dd, i2c_target(target), 0);
- if (ret) /* failed - release the module */
- module_put(THIS_MODULE);
-
- return ret;
+ return acquire_chip_resource(ppd->dd, i2c_target(target), 0);
}

static int i2c1_debugfs_open(struct inode *in, struct file *fp)
@@ -1013,7 +1008,6 @@ static int __i2c_debugfs_release(struct inode *in, struct file *fp, u32 target)
ppd = private2ppd(fp);

release_chip_resource(ppd->dd, i2c_target(target));
- module_put(THIS_MODULE);

return 0;
}
@@ -1031,18 +1025,10 @@ static int i2c2_debugfs_release(struct inode *in, struct file *fp)
static int __qsfp_debugfs_open(struct inode *in, struct file *fp, u32 target)
{
struct hfi1_pportdata *ppd;
- int ret;
-
- if (!try_module_get(THIS_MODULE))
- return -ENODEV;

ppd = private2ppd(fp);

- ret = acquire_chip_resource(ppd->dd, i2c_target(target), 0);
- if (ret) /* failed - release the module */
- module_put(THIS_MODULE);
-
- return ret;
+ return acquire_chip_resource(ppd->dd, i2c_target(target), 0);
}

static int qsfp1_debugfs_open(struct inode *in, struct file *fp)
@@ -1062,7 +1048,6 @@ static int __qsfp_debugfs_release(struct inode *in, struct file *fp, u32 target)
ppd = private2ppd(fp);

release_chip_resource(ppd->dd, i2c_target(target));
- module_put(THIS_MODULE);

return 0;
}
--
2.25.1