Messages in this thread |  | | | Date | Wed, 9 Feb 2011 12:53:37 +0100 | | From | Johannes Stezenbach <> | | Subject | Re: [PATCH -v3] Only honor the FIGETBSZ ioctl for regular files and directories |
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(restore Cc:s)
On Wed, Feb 09, 2011 at 09:13:50AM +0100, anders franzen wrote: > > Vad happened with the patch below. It was ''signed off'' more than > half a year ago, and it is not in any of the latest kernel yet. > > I ask, because I spend a week debugging the 'dvbloopback' driver, > which uses '2' as a private ioctl for a read command. Not easy to > find. > > Can a driver not have private ioctls? > Should this be fixed in the driver?, I have now RESERVED the value 2 > in the driver. But this does not > guarantee that someone invents FIGETBSZ_V2 and assigned the value 3 to it. > > Regards > /Anders > > > > > FIGETBSZ has an ioctl number of _IO(0x00,2) == 2, which can conflict > with device driver ioctls. Let's avoid the potential for problems by > only honoring the ioctl number for files where this ioctl is likely > going to be useful: for regular files and directories > > Thanks to Johannes Stezenbach for pointing this consequence of commit > 19ba0559. > > Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx> > Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> > Cc: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx> > Cc: Johannes Stezenbach <js@xxxxxxxxx> > --- > > Fixed up commit description > > fs/compat_ioctl.c | 6 +++++- > fs/ioctl.c | 5 ++++- > 2 files changed, 9 insertions(+), 2 deletions(-) > > diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c > index 641640d..b8607fe 100644 > --- a/fs/compat_ioctl.c > +++ b/fs/compat_ioctl.c > @@ -1715,8 +1715,12 @@ asmlinkage long compat_sys_ioctl(unsigned int > fd, unsigned int cmd, > goto out_fput; > #endif > - case FIBMAP: > case FIGETBSZ: > + if (S_ISDIR(filp->f_path.dentry->d_inode->i_mode)) > + break; > + /*FALL THROUGH */ > + > + case FIBMAP: > case FIONREAD: > if (S_ISREG(filp->f_path.dentry->d_inode->i_mode)) > break; > diff --git a/fs/ioctl.c b/fs/ioctl.c > index 2d140a7..e578dab 100644 > --- a/fs/ioctl.c > +++ b/fs/ioctl.c > @@ -597,7 +597,10 @@ int do_vfs_ioctl(struct file *filp, unsigned > int fd, unsigned int cmd, > { > struct inode *inode = filp->f_path.dentry->d_inode; > int __user *p = (int __user *)arg; > - return put_user(inode->i_sb->s_blocksize, p); > + > + if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)) > + return put_user(inode->i_sb->s_blocksize, p); > + /* FALL THROUGH */ > } > > default: > -- > 1.7.0.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >
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