Messages in this thread | | | Subject | Re: [PATCH 05/10] comedi: get rid of compat_alloc_user_space() mess in COMEDI_INSN compat | From | Ian Abbott <> | Date | Fri, 29 May 2020 11:05:34 +0100 |
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On 29/05/2020 01:35, Al Viro wrote: > From: Al Viro <viro@zeniv.linux.org.uk> > > Just take copy_from_user() out of do_insn_ioctl() into the caller and > have compat_insn() build a native version and pass it to do_insn_ioctl() > directly. > > One difference from the previous commits is that the helper used to > convert 32bit variant to native has two users - compat_insn() and > compat_insnlist(). The latter will be converted in next commit; > for now we simply split the helper in two variants - "userland 32bit > to kernel native" and "userland 32bit to userland native". The latter > is renamed old get_compat_insn(); it will be gone in the next commit. > > Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> > --- > drivers/staging/comedi/comedi_fops.c | 73 +++++++++++++++++++++++------------- > 1 file changed, 46 insertions(+), 27 deletions(-) > > diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c > index d96dc85d8a98..ae0067ab5ead 100644 [snip] > @@ -2244,10 +2241,13 @@ static long comedi_unlocked_ioctl(struct file *file, unsigned int cmd, > (struct comedi_insnlist __user *)arg, > file); > break; > - case COMEDI_INSN: > - rc = do_insn_ioctl(dev, (struct comedi_insn __user *)arg, > - file); > + case COMEDI_INSN: { > + struct comedi_insn insn; > + if (copy_from_user(&insn, (void __user *)arg, sizeof(insn))) > + rc = -EFAULT;
Missing an 'else' here:
> + rc = do_insn_ioctl(dev, &insn, file); > break; > + } > case COMEDI_POLL:
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