Hi, Sudip On 12/30/2015 07:16 PM, Sudip Mukherjee wrote: > On Fri, Dec 18, 2015 at 12:12:05AM +0100, Arnd Bergmann wrote: >> On Thursday 17 December 2015 17:58:52 Bamvor Jian Zhang wrote: >>> The arg of ioctl in ppdev is the pointer of integer except the >>> timeval in PPSETTIME, PPGETTIME. Different size of timeval >>> is already supported by the previous patches. So, it is safe >>> to add compat support. >>> >>> Signed-off-by: Bamvor Jian Zhang <bamvor.zhangj...@linaro.org> >>> >> >> Reviewed-by: Arnd Bergmann <a...@arndb.de> >> >> (I think I replied with the reviewed-by tag before to this patch) > > I was testing this series today. And it is breaking my userspace code. I > am attaching my userspace code for you to check. Its very simple > userspace code: > 1: open > 2: ioctl to claim > 3: ioctl - PPGETTIME > 4: ioctl - PPSETTIME > 5: ioctl - PPGETTIME > 6: ioctl - release > 7: close > > Without this series it works as expected. > > With this series applied, the userspace code prints the error message: > PPNEGOT: Bad address > > I traced it with strace and: > ioctl(3, PPGETTIME, 0xbfe91508) = -1 EFAULT (Bad address) Thanks for your testing. It seems that I misuse the parameters. Could you please apply the following patch and try it again? There is no parport in my computer, Thanks.
diff --git a/drivers/char/ppdev.c b/drivers/char/ppdev.c index 31bc7b7..9e98d01 100644 --- a/drivers/char/ppdev.c +++ b/drivers/char/ppdev.c @@ -636,7 +636,7 @@ static int pp_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg) if ((time32[0] < 0) || (time32[1] < 0)) return -EINVAL; - if (copy_to_user(time32, argp, sizeof(time32))) + if (copy_to_user(argp, time32, sizeof(time32))) return -EFAULT; return 0; @@ -648,7 +648,7 @@ static int pp_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg) if ((time64[0] < 0) || (time64[1] < 0)) return -EINVAL; - if (copy_to_user(time64, argp, sizeof(time64))) + if (copy_to_user(argp, time64, sizeof(time64))) return -EFAULT; return 0; Regards Bamvor > > regards > sudip > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/