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Message-ID: <b123bd21-241c-de06-c3d7-e4505ee6e1e3@quicinc.com>
Date:   Tue, 8 Nov 2022 11:59:34 +0530
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Subject: Re: [PATCH] selftests: cgroup: Fix unsigned comparison with less than
 zero
Content-Language: en-US
To:     YueHaibing <yuehaibing@huawei.com>, <tj@kernel.org>,
        <lizefan.x@bytedance.com>, <hannes@cmpxchg.org>,
        <shuah@kernel.org>, <yosryahmed@google.com>,
        <roman.gushchin@linux.dev>, <shakeelb@google.com>,
        <rientjes@google.com>, <akpm@linux-foundation.org>
CC:     <cgroups@vger.kernel.org>, <linux-kselftest@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
References: <20221105110611.28920-1-yuehaibing@huawei.com>
From:   Mukesh Ojha <quic_mojha@quicinc.com>
In-Reply-To: <20221105110611.28920-1-yuehaibing@huawei.com>
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Hi,

On 11/5/2022 4:36 PM, YueHaibing wrote:
> 'size' is unsigned, it never less than zero.
> 
> Fixes: 6c26df84e1f2 ("selftests: cgroup: return -errno from cg_read()/cg_write() on failure")
> Signed-off-by: YueHaibing <yuehaibing@huawei.com>

LGTM.
Reviewed-by: Mukesh Ojha <quic_mojha@quicinc.com>

-Mukesh
> ---
>   tools/testing/selftests/cgroup/cgroup_util.c | 5 +++--
>   1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/testing/selftests/cgroup/cgroup_util.c b/tools/testing/selftests/cgroup/cgroup_util.c
> index 4c52cc6f2f9c..e8bbbdb77e0d 100644
> --- a/tools/testing/selftests/cgroup/cgroup_util.c
> +++ b/tools/testing/selftests/cgroup/cgroup_util.c
> @@ -555,6 +555,7 @@ int proc_mount_contains(const char *option)
>   ssize_t proc_read_text(int pid, bool thread, const char *item, char *buf, size_t size)
>   {
>   	char path[PATH_MAX];
> +	ssize_t ret;
>   
>   	if (!pid)
>   		snprintf(path, sizeof(path), "/proc/%s/%s",
> @@ -562,8 +563,8 @@ ssize_t proc_read_text(int pid, bool thread, const char *item, char *buf, size_t
>   	else
>   		snprintf(path, sizeof(path), "/proc/%d/%s", pid, item);
>   
> -	size = read_text(path, buf, size);
> -	return size < 0 ? -1 : size;
> +	ret = read_text(path, buf, size);
> +	return ret < 0 ? -1 : ret;
>   }
>   
>   int proc_read_strstr(int pid, bool thread, const char *item, const char *needle)