From: Al Viro <viro@ZenIV.linux.org.uk>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Theodore Ts'o <tytso@mit.edu>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH 06/11] compat_ioctl: remove /dev/random commands
Date: Sun, 9 Sep 2018 05:11:23 +0100 [thread overview]
Message-ID: <20180909041114.GD19965@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20180908142837.2819693-6-arnd@arndb.de>
On Sat, Sep 08, 2018 at 04:28:12PM +0200, Arnd Bergmann wrote:
> These are all handled by the random driver, so instead of listing
> each ioctl, we can just use the same function to deal with both
> native and compat commands.
Umm... I don't think it's right -
> .unlocked_ioctl = random_ioctl,
> + .compat_ioctl = random_ioctl,
->compat_ioctl() gets called in
error = f.file->f_op->compat_ioctl(f.file, cmd, arg);
so you do *NOT* get compat_ptr() for those - they have to do it on their
own. It's not hard to provide a proper compat_ioctl() instance for that
one, but this is not it. What you need in drivers/char/random.c part of
that one is something like
diff --git a/drivers/char/random.c b/drivers/char/random.c
index bf5f99fc36f1..1de75c784cf6 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -1954,10 +1954,9 @@ static ssize_t random_write(struct file *file, const char __user *buffer,
return (ssize_t)count;
}
-static long random_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
+static long __random_ioctl(struct file *f, unsigned int cmd, int __user *p)
{
int size, ent_count;
- int __user *p = (int __user *)arg;
int retval;
switch (cmd) {
@@ -2011,6 +2010,18 @@ static long random_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
}
}
+static long random_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
+{
+ return __random_ioctl(f, cmd, (int __user *)arg);
+}
+
+#ifdef CONFIG_COMPAT
+static long compat_random_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
+{
+ return __random_ioctl(f, cmd, compat_ptr(arg));
+}
+#endif
+
static int random_fasync(int fd, struct file *filp, int on)
{
return fasync_helper(fd, filp, on, &fasync);
@@ -2021,6 +2032,9 @@ const struct file_operations random_fops = {
.write = random_write,
.poll = random_poll,
.unlocked_ioctl = random_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = compat_random_ioctl,
+#endif
.fasync = random_fasync,
.llseek = noop_llseek,
};
next prev parent reply other threads:[~2018-09-09 9:00 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-08 14:28 [PATCH 01/11] compat_ioctl: remove keyboard ioctl translation Arnd Bergmann
2018-09-08 14:28 ` [PATCH 02/11] compat_ioctl: remove HIDIO translation Arnd Bergmann
2018-09-08 14:28 ` [PATCH 03/11] compat_ioctl: remove translation for sound ioctls Arnd Bergmann
2018-09-09 4:16 ` Al Viro
2018-09-11 19:35 ` Arnd Bergmann
2018-09-08 14:28 ` [PATCH 04/11] compat_ioctl: remove isdn ioctl translation Arnd Bergmann
2018-09-08 14:28 ` [PATCH 05/11] compat_ioctl: remove IGNORE_IOCTL() Arnd Bergmann
2018-09-08 14:28 ` [PATCH 06/11] compat_ioctl: remove /dev/random commands Arnd Bergmann
2018-09-09 4:11 ` Al Viro [this message]
2018-09-11 20:26 ` Arnd Bergmann
2018-09-12 5:28 ` Martin Schwidefsky
2018-09-12 14:02 ` Arnd Bergmann
2018-09-13 6:42 ` Martin Schwidefsky
2018-09-13 8:13 ` Arnd Bergmann
2018-09-08 14:28 ` [PATCH 07/11] compat_ioctl: remove joystick ioctl translation Arnd Bergmann
2018-09-08 14:28 ` [PATCH 08/11] compat_ioctl: remove PCI " Arnd Bergmann
2018-09-08 14:28 ` [PATCH 09/11] compat_ioctl: remove /dev/raw " Arnd Bergmann
2018-09-08 14:28 ` [PATCH 10/11] compat_ioctl: remove last RAID handling code Arnd Bergmann
2018-09-08 14:28 ` [PATCH 11/11] compat_ioctl: move tape handling into drivers Arnd Bergmann
2018-09-09 4:37 ` Al Viro
2018-09-11 15:36 ` Arnd Bergmann
2018-09-11 20:13 ` Arnd Bergmann
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