Messages in this thread | | | Date | Thu, 12 May 2016 15:27:27 -0400 | From | Dennis Dalessandro <> | Subject | Re: [PATCH v2 3/5] IB/hfi1: Add ioctl() interface for user commands |
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On Thu, May 12, 2016 at 11:43:32AM -0600, Jason Gunthorpe wrote: >On Thu, May 12, 2016 at 10:18:47AM -0700, Dennis Dalessandro wrote: >> + case HFI1_IOCTL_EP_INFO: >> + case HFI1_IOCTL_EP_ERASE_CHIP: >> + case HFI1_IOCTL_EP_ERASE_RANGE: >> + case HFI1_IOCTL_EP_READ_RANGE: >> + case HFI1_IOCTL_EP_WRITE_RANGE: >> + if (!capable(CAP_SYS_ADMIN)) >> + return -EPERM; >> + if (copy_from_user(&ucmd, >> + (struct hfi11_cmd __user *)arg, >> + sizeof(ucmd))) >> + return -EFAULT; >> + return handle_eprom_command(fp, &ucmd); > >I thought we agreed to get rid of this as well? It certainly does not >belong here, and as a general rule, I don't think ioctls should be >doing capable tests..
Yeah. I left it in this patch set because this just "ports" our existing code to ioctl(). The eprom stuff is completely removed in another patch set that I posted shortly after this. It's at:
http://marc.info/?l=linux-rdma&m=146307409301822&w=2
>> +static inline int check_ioctl_access(unsigned int cmd, unsigned long arg) >> +{ >> + int read_cmd, write_cmd, read_ok, write_ok; >> + >> + read_cmd = _IOC_DIR(cmd) & _IOC_READ; >> + write_cmd = _IOC_DIR(cmd) & _IOC_WRITE; >> + write_ok = access_ok(VERIFY_WRITE, (void __user *)arg, _IOC_SIZE(cmd)); >> + read_ok = access_ok(VERIFY_READ, (void __user *)arg, _IOC_SIZE(cmd)); >> + >> + if ((read_cmd && !write_ok) || (write_cmd && !read_ok)) >> + return -EFAULT; > >This seems kind of goofy, didn't Ira say this is performance senstive?
I'll let Ira comment here on the performance aspect. I agree it looks goofy. Suggestion on how to make it look better? Or are you saying this is incorrect?
>Driver shouldn't be open coding __get_user like that, IMHO.
Can you explain what you mean here? We should not use __get_user()?
> >> +#define HFI1_IOCTL_RECV_CTRL \ >> + _IOW(IB_IOCTL_MAGIC, HFI1_CMD_RECV_CTRL, int) > >Have you audited this? Confused why this is marked IOW when I see >this: > >+ case HFI1_IOCTL_RECV_CTRL: >+ ret = __get_user(uval, (int __user *)arg); > >Seeing many other examples. > >I stopped looking again
_IOW means user is writing data to the device. So the device is reading data from the user. Or am I missing your point?
-Denny
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