From: Julia Lawall <julia.lawall@inria.fr>
To: Joe Perches <joe@perches.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"Rafael J. Wysocki" <rafael@kernel.org>,
Kees Cook <keescook@chromium.org>,
"Gustavo A . R . Silva" <gustavoars@kernel.org>,
Denis Efremov <efremov@linux.com>,
Julia Lawall <julia.lawall@inria.fr>,
Alex Dewar <alex.dewar90@gmail.com>,
Jonathan Corbet <corbet@lwn.net>,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH V2] sysfs: Add sysfs_emit and sysfs_emit_at to format sysfs output
Date: Sun, 30 Aug 2020 10:59:40 +0200 (CEST) [thread overview]
Message-ID: <alpine.DEB.2.22.394.2008301059080.3629@hadrien> (raw)
In-Reply-To: <c22b7006813b1776467a72e716a5970e9277b4b7.camel@perches.com>
On Sat, 29 Aug 2020, Joe Perches wrote:
> On Sat, 2020-08-29 at 16:48 -0700, Joe Perches wrote:
> > Output defects can exist in sysfs content using sprintf and snprintf.
> >
> > sprintf does not know the PAGE_SIZE maximum of the temporary buffer
> > used for outputting sysfs content and it's possible to overrun the
> > PAGE_SIZE buffer length.
> >
> > Add a generic sysfs_emit function that knows that the size of the
> > temporary buffer and ensures that no overrun is done.
> >
> > Add a generic sysfs_emit_at function that can be used in multiple
> > call situations that also ensures that no overrun is done.
>
> This preliminary coccinelle script converts ~5000 instances treewide.
> There are still many remaining instances that could be converted.
Except for the issue with the ...s that has been discussed, this looks
basically reasonable to me.
julia
>
> $ git grep -w sysfs_emit -- '*.[ch]'|wc -l
> 4702
> $ git grep -w sysfs_emit_at -- '*.[ch]'|wc -l
> 229
>
> $ cat sysfs_emit.cocci
> @@
> identifier d_show =~ "^.*show.*$";
> identifier arg1, arg2, arg3;
> @@
> ssize_t d_show(struct device *
> - arg1
> + dev
> , struct device_attribute *
> - arg2
> + attr
> , char *
> - arg3
> + buf
> )
> {
> ...
> (
> - arg1
> + dev
> |
> - arg2
> + attr
> |
> - arg3
> + buf
> )
> ...
> }
>
> @@
> identifier d_show =~ "^.*show.*$";
> identifier dev, attr, buf;
> @@
>
> ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
> {
> <...
> return
> - sprintf(buf,
> + sysfs_emit(buf,
> ...);
> ...>
> }
>
> @@
> identifier d_show =~ "^.*show.*$";
> identifier dev, attr, buf;
> @@
>
> ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
> {
> <...
> return
> - snprintf(buf, PAGE_SIZE,
> + sysfs_emit(buf,
> ...);
> ...>
> }
>
> @@
> identifier d_show =~ "^.*show.*$";
> identifier dev, attr, buf;
> @@
>
> ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
> {
> <...
> return
> - scnprintf(buf, PAGE_SIZE,
> + sysfs_emit(buf,
> ...);
> ...>
> }
>
> @@
> identifier d_show =~ "^.*show.*$";
> identifier dev, attr, buf;
> expression chr;
> @@
>
> ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
> {
> <...
> return
> - strcpy(buf, chr);
> + sysfs_emit(buf, chr);
> ...>
> }
>
> @@
> identifier d_show =~ "^.*show.*$";
> identifier dev, attr, buf;
> identifier len;
> @@
>
> ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
> {
> <...
> len =
> - sprintf(buf,
> + sysfs_emit(buf,
> ...);
> ...>
> return len;
> }
>
> @@
> identifier d_show =~ "^.*show.*$";
> identifier dev, attr, buf;
> identifier len;
> @@
>
> ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
> {
> <...
> len =
> - snprintf(buf, PAGE_SIZE,
> + sysfs_emit(buf,
> ...);
> ...>
> return len;
> }
>
> @@
> identifier d_show =~ "^.*show.*$";
> identifier dev, attr, buf;
> identifier len;
> @@
>
> ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
> {
> <...
> len =
> - scnprintf(buf, PAGE_SIZE,
> + sysfs_emit(buf,
> ...);
> ...>
> return len;
> }
>
> @@
> identifier d_show =~ "^.*show.*$";
> identifier dev, attr, buf;
> identifier len;
> @@
>
> ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
> {
> <...
> - len += scnprintf(buf + len, PAGE_SIZE - len,
> + len += sysfs_emit_at(buf, len,
> ...);
> ...>
> return len;
> }
>
> @@
> identifier d_show =~ "^.*show.*$";
> identifier dev, attr, buf;
> expression chr;
> @@
>
> ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
> {
> - strcpy(buf, chr);
> - return strlen(buf);
> + return sysfs_emit(buf, chr);
> }
>
> @@
> identifier k_show =~ "^.*show.*$";
> identifier arg1, arg2, arg3;
> @@
> ssize_t k_show(struct kobject *
> - arg1
> + kobj
> , struct kobj_attribute *
> - arg2
> + attr
> , char *
> - arg3
> + buf
> )
> {
> ...
> (
> - arg1
> + kobj
> |
> - arg2
> + attr
> |
> - arg3
> + buf
> )
> ...
> }
>
> @@
> identifier k_show =~ "^.*show.*$";
> identifier kobj, attr, buf;
> @@
>
> ssize_t k_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
> {
> <...
> return
> - sprintf(buf,
> + sysfs_emit(buf,
> ...);
> ...>
> }
>
> @@
> identifier k_show =~ "^.*show.*$";
> identifier kobj, attr, buf;
> @@
>
> ssize_t k_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
> {
> <...
> return
> - snprintf(buf, PAGE_SIZE,
> + sysfs_emit(buf,
> ...);
> ...>
> }
>
> @@
> identifier k_show =~ "^.*show.*$";
> identifier kobj, attr, buf;
> @@
>
> ssize_t k_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
> {
> <...
> return
> - scnprintf(buf, PAGE_SIZE,
> + sysfs_emit(buf,
> ...);
> ...>
> }
>
> @@
> identifier k_show =~ "^.*show.*$";
> identifier kobj, attr, buf;
> expression chr;
> @@
>
> ssize_t k_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
> {
> <...
> return
> - strcpy(buf, chr);
> + sysfs_emit(buf, chr);
> ...>
> }
>
> @@
> identifier k_show =~ "^.*show.*$";
> identifier kobj, attr, buf;
> identifier len;
> @@
>
> ssize_t k_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
> {
> <...
> len =
> - sprintf(buf,
> + sysfs_emit(buf,
> ...);
> ...>
> return len;
> }
>
> @@
> identifier k_show =~ "^.*show.*$";
> identifier kobj, attr, buf;
> identifier len;
> @@
>
> ssize_t k_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
> {
> <...
> len =
> - snprintf(buf, PAGE_SIZE,
> + sysfs_emit(buf,
> ...);
> ...>
> return len;
> }
>
> @@
> identifier k_show =~ "^.*show.*$";
> identifier kobj, attr, buf;
> identifier len;
> @@
>
> ssize_t k_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
> {
> <...
> len =
> - scnprintf(buf, PAGE_SIZE,
> + sysfs_emit(buf,
> ...);
> ...>
> return len;
> }
>
> @@
> identifier k_show =~ "^.*show.*$";
> identifier kobj, attr, buf;
> identifier len;
> @@
>
> ssize_t k_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
> {
> <...
> - len += scnprintf(buf + len, PAGE_SIZE - len,
> + len += sysfs_emit_at(buf, len,
> ...);
> ...>
> return len;
> }
>
> @@
> identifier k_show =~ "^.*show.*$";
> identifier kobj, attr, buf;
> expression chr;
> @@
>
> ssize_t k_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
> {
> - strcpy(buf, chr);
> - return strlen(buf);
> + return sysfs_emit(buf, chr);
> }
>
>
>
next prev parent reply other threads:[~2020-08-30 8:59 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-29 23:48 Joe Perches
2020-08-30 0:43 ` Joe Perches
2020-08-30 8:59 ` Julia Lawall [this message]
2020-08-30 15:25 ` Denis Efremov
2020-08-30 16:05 ` Joe Perches
2020-09-07 13:36 ` Greg Kroah-Hartman
2020-09-06 17:24 ` Joe Perches
2020-09-07 5:48 ` Greg Kroah-Hartman
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