Commit 286ce4c6 authored by Xiang Chen's avatar Xiang Chen Committed by Martin K. Petersen
Browse files

scsi: hisi_sas: Limit users changing debugfs BIST count value 

Add a file operation for "cnt" file under bist directory, so users can only
read "cnt" or clear "cnt" to zero, but cannot randomly modify.

Link: https://lore.kernel.org/r/1645703489-87194-6-git-send-email-john.garry@huawei.com


Signed-off-by: default avatarXiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: default avatarQi Liu <liuqi115@huawei.com>
Signed-off-by: default avatarJohn Garry <john.garry@huawei.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 86287065

drivers/scsi/hisi_sas/hisi_sas_v3_hw.c

+50 −2
Original line number Diff line number Diff line
@@ -3975,6 +3975,54 @@ static const struct file_operations debugfs_bist_phy_v3_hw_fops = { 
	.owner = THIS_MODULE,

};



static ssize_t debugfs_bist_cnt_v3_hw_write(struct file *filp,

					const char __user *buf,

					size_t count, loff_t *ppos)

{

	struct seq_file *m = filp->private_data;

	struct hisi_hba *hisi_hba = m->private;

	unsigned int cnt;

	int val;



	if (hisi_hba->debugfs_bist_enable)

		return -EPERM;



	val = kstrtouint_from_user(buf, count, 0, &cnt);

	if (val)

		return val;



	if (cnt)

		return -EINVAL;



	hisi_hba->debugfs_bist_cnt = 0;

	return count;

}



static int debugfs_bist_cnt_v3_hw_show(struct seq_file *s, void *p)

{

	struct hisi_hba *hisi_hba = s->private;



	seq_printf(s, "%u\n", hisi_hba->debugfs_bist_cnt);



	return 0;

}



static int debugfs_bist_cnt_v3_hw_open(struct inode *inode,

					  struct file *filp)

{

	return single_open(filp, debugfs_bist_cnt_v3_hw_show,

			   inode->i_private);

}



static const struct file_operations debugfs_bist_cnt_v3_hw_ops = {

	.open = debugfs_bist_cnt_v3_hw_open,

	.read = seq_read,

	.write = debugfs_bist_cnt_v3_hw_write,

	.llseek = seq_lseek,

	.release = single_release,

	.owner = THIS_MODULE,

};



static const struct {

	int		value;

	char		*name;
@@ -4612,8 +4660,8 @@ static void debugfs_bist_init_v3_hw(struct hisi_hba *hisi_hba) 
	debugfs_create_file("phy_id", 0600, hisi_hba->debugfs_bist_dentry,

			    hisi_hba, &debugfs_bist_phy_v3_hw_fops);



	debugfs_create_u32("cnt", 0600, hisi_hba->debugfs_bist_dentry,

			   &hisi_hba->debugfs_bist_cnt);

	debugfs_create_file("cnt", 0600, hisi_hba->debugfs_bist_dentry,

			    hisi_hba, &debugfs_bist_cnt_v3_hw_ops);



	debugfs_create_file("loopback_mode", 0600,

			    hisi_hba->debugfs_bist_dentry,