[PATCH v3 3/6] parport: Remove register_sysctl_table from parport_device_proc_register

From: Joel Granados
Date: Tue May 16 2023 - 12:30:44 EST


This is part of the general push to deprecate register_sysctl_paths and
register_sysctl_table. We use a temp allocation to include both port and
device name in proc. Allocated mem is freed at the end. The unused
parport_device_sysctl_template struct elements that are not used are
removed.

Signed-off-by: Joel Granados <j.granados@xxxxxxxxxxx>
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Closes: https://lore.kernel.org/r/202305150948.pHgIh7Ql-lkp@xxxxxxxxx/
Reported-by: Dan Carpenter <error27@xxxxxxxxx>
Closes: https://lore.kernel.org/r/202305150948.pHgIh7Ql-lkp@xxxxxxxxx/
Reviewed-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>
---
drivers/parport/procfs.c | 56 +++++++++++++++++++++++-----------------
1 file changed, 32 insertions(+), 24 deletions(-)

diff --git a/drivers/parport/procfs.c b/drivers/parport/procfs.c
index 02c52de6e640..a2b58da1fe86 100644
--- a/drivers/parport/procfs.c
+++ b/drivers/parport/procfs.c
@@ -384,6 +384,7 @@ parport_device_sysctl_template = {
.extra1 = (void*) &parport_min_timeslice_value,
.extra2 = (void*) &parport_max_timeslice_value
},
+ {}
},
{
{
@@ -394,22 +395,6 @@ parport_device_sysctl_template = {
.child = NULL
},
{}
- },
- {
- PARPORT_DEVICES_ROOT_DIR,
- {}
- },
- {
- PARPORT_PORT_DIR(NULL),
- {}
- },
- {
- PARPORT_PARPORT_DIR(NULL),
- {}
- },
- {
- PARPORT_DEV_DIR(NULL),
- {}
}
};

@@ -546,30 +531,53 @@ int parport_proc_unregister(struct parport *port)

int parport_device_proc_register(struct pardevice *device)
{
+ int bytes_written, err = 0;
struct parport_device_sysctl_table *t;
struct parport * port = device->port;
+ size_t port_name_len, device_name_len, tmp_dir_path_len;
+ char *tmp_dir_path;

t = kmemdup(&parport_device_sysctl_template, sizeof(*t), GFP_KERNEL);
if (t == NULL)
return -ENOMEM;

- t->dev_dir[0].child = t->parport_dir;
- t->parport_dir[0].child = t->port_dir;
- t->port_dir[0].procname = port->name;
- t->port_dir[0].child = t->devices_root_dir;
- t->devices_root_dir[0].child = t->device_dir;
+ port_name_len = strnlen(port->name, PARPORT_NAME_MAX_LEN);
+ device_name_len = strnlen(device->name, PATH_MAX);
+
+ /* Allocate a buffer for two paths: dev/parport/PORT/devices/DEVICE. */
+ tmp_dir_path_len = PARPORT_BASE_DEVICES_PATH_SIZE + port_name_len + device_name_len;
+ tmp_dir_path = kzalloc(tmp_dir_path_len, GFP_KERNEL);
+ if (!tmp_dir_path) {
+ err = -ENOMEM;
+ goto exit_free_t;
+ }
+
+ bytes_written = snprintf(tmp_dir_path, tmp_dir_path_len, "dev/parport/%s/devices/%s",
+ port->name, device->name);
+ if (tmp_dir_path_len <= bytes_written) {
+ err = -ENOENT;
+ goto exit_free_path;
+ }

- t->device_dir[0].procname = device->name;
- t->device_dir[0].child = t->vars;
t->vars[0].data = &device->timeslice;

- t->sysctl_header = register_sysctl_table(t->dev_dir);
+ t->sysctl_header = register_sysctl(tmp_dir_path, t->vars);
if (t->sysctl_header == NULL) {
kfree(t);
t = NULL;
}
device->sysctl_table = t;
+
+ kfree(tmp_dir_path);
return 0;
+
+exit_free_path:
+ kfree(tmp_dir_path);
+
+exit_free_t:
+ kfree(t);
+
+ return err;
}

int parport_device_proc_unregister(struct pardevice *device)
--
2.30.2