Date:   Wed, 8 Dec 2021 10:02:05 +0800
From:   Gao Xiang <xiang@kernel.org>
To:     Huang Jianan <jnhuang95@gmail.com>
Cc:     linux-erofs@lists.ozlabs.org, xiang@kernel.org, chao@kernel.org,
        linux-kernel@vger.kernel.org, guoweichao@oppo.com,
        guanyuwei@oppo.com, yh@oppo.com, zhangshiming@oppo.com,
        Huang Jianan <huangjianan@oppo.com>
Subject: Re: [PATCH v7 2/3] erofs: add sysfs interface
Message-ID: <20211208020204.GA13528@hsiangkao-HP-ZHAN-66-Pro-G1>
Mail-Followup-To: Huang Jianan <jnhuang95@gmail.com>,
        linux-erofs@lists.ozlabs.org, xiang@kernel.org, chao@kernel.org,
        linux-kernel@vger.kernel.org, guoweichao@oppo.com,
        guanyuwei@oppo.com, yh@oppo.com, zhangshiming@oppo.com,
        Huang Jianan <huangjianan@oppo.com>
References: <CAJfKizqxkt4BYa26cmOgCD9OFOck_J0NZ8hxCQbVoyv0j4SMJg@mail.gmail.com>
 <20211201145436.4357-1-huangjianan@oppo.com>
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Hi Jianan,

On Wed, Dec 01, 2021 at 10:54:36PM +0800, Huang Jianan wrote:
> Add sysfs interface to configure erofs related parameters later.
> 
> Signed-off-by: Huang Jianan <huangjianan@oppo.com>
> Reviewed-by: Chao Yu <chao@kernel.org>

...

> +static ssize_t erofs_attr_store(struct kobject *kobj, struct attribute *attr,
> +						const char *buf, size_t len)
> +{
> +	struct erofs_sb_info *sbi = container_of(kobj, struct erofs_sb_info,
> +						s_kobj);
> +	struct erofs_attr *a = container_of(attr, struct erofs_attr, attr);
> +	unsigned char *ptr = __struct_ptr(sbi, a->struct_type, a->offset);
> +	unsigned long t;
> +	int ret;
> +
> +	switch (a->attr_id) {
> +	case attr_pointer_ui:
> +		if (!ptr)
> +			return 0;
> +		ret = kstrtoul(skip_spaces(buf), 0, &t);
> +		if (ret)
> +			return ret;
> +		if (t > UINT_MAX)
> +			return -EINVAL;

Intel 0day CI report a warning.
https://lore.kernel.org/r/61aede22.lQ5T3RqGz2H%2Fg4aR%25lkp@intel.com

I fix this like below:

diff --git a/fs/erofs/sysfs.c b/fs/erofs/sysfs.c
index 41a7de772412..33e15fa63c82 100644
--- a/fs/erofs/sysfs.c
+++ b/fs/erofs/sysfs.c
@@ -128,8 +128,8 @@ static ssize_t erofs_attr_store(struct kobject *kobj, struct attribute *attr,
                ret = kstrtoul(skip_spaces(buf), 0, &t);
                if (ret)
                        return ret;
-               if (t > UINT_MAX)
-                       return -EINVAL;
+               if (t != (unsigned int)t)
+                       return -ERANGE;
                *(unsigned int *)ptr = t;
                return len;
        case attr_pointer_bool:

Thanks,
Gao Xiang