On Wed, Aug 29, 2018 at 04:03:30PM +0200, Arnd Bergmann wrote: > The ppp_idle structure is defined in terms of __kernel_time_t, which is > defined as 'long' on all architectures, and this usage is not affected > by the y2038 problem since it transports a time interval rather than an > absolute time. > > However, the ppp user space defines the same structure as time_t, which > may be 64-bit wide on new libc versions even on 32-bit architectures. > > It's easy enough to just handle both possible structure layouts on > all architectures, to deal with the possibility that a user space ppp > implementation comes with its own ppp_idle structure definition, as well > as to document the fact that the driver is y2038-safe. > > Doing this also avoids the need for a special compat mode translation, > since 32-bit and 64-bit kernels now support the same interfaces. > > Signed-off-by: Arnd Bergmann <[email protected]> > --- > Documentation/networking/ppp_generic.txt | 2 ++ > drivers/isdn/i4l/isdn_ppp.c | 14 ++++++++--- > drivers/net/ppp/ppp_generic.c | 18 ++++++++++---- > fs/compat_ioctl.c | 31 ------------------------ > include/uapi/linux/ppp-ioctl.h | 2 ++ > include/uapi/linux/ppp_defs.h | 14 +++++++++++ > 6 files changed, 42 insertions(+), 39 deletions(-) > > diff --git a/Documentation/networking/ppp_generic.txt > b/Documentation/networking/ppp_generic.txt > index 61daf4b39600..fd563aff5fc9 100644 > --- a/Documentation/networking/ppp_generic.txt > +++ b/Documentation/networking/ppp_generic.txt > @@ -378,6 +378,8 @@ an interface unit are: > CONFIG_PPP_FILTER option is enabled, the set of packets which reset > the transmit and receive idle timers is restricted to those which > pass the `active' packet filter. > + Two versions of this command exist, to deal with user space > + expecting times as either 32-bit or 64-bit time_t seconds. > > * PPPIOCSMAXCID sets the maximum connection-ID parameter (and thus the > number of connection slots) for the TCP header compressor and > diff --git a/drivers/isdn/i4l/isdn_ppp.c b/drivers/isdn/i4l/isdn_ppp.c > index a7b275ea5de1..1f17126c5fa4 100644 > --- a/drivers/isdn/i4l/isdn_ppp.c > +++ b/drivers/isdn/i4l/isdn_ppp.c > @@ -543,11 +543,19 @@ isdn_ppp_ioctl(int min, struct file *file, unsigned int > cmd, unsigned long arg) > } > is->pppcfg = val; > break; > - case PPPIOCGIDLE: /* get idle time information */ > + case PPPIOCGIDLE32: /* get idle time information */ > if (lp) { > - struct ppp_idle pidle; > + struct ppp_idle32 pidle; > pidle.xmit_idle = pidle.recv_idle = lp->huptimer; > - if ((r = set_arg(argp, &pidle, sizeof(struct > ppp_idle)))) > + if ((r = set_arg(argp, &pidle, sizeof(struct > ppp_idle32)))) > + return r; > + } > + break; > + case PPPIOCGIDLE64: /* get idle time information */ > + if (lp) { > + struct ppp_idle64 pidle; > + pidle.xmit_idle = pidle.recv_idle = lp->huptimer; > + if ((r = set_arg(argp, &pidle, sizeof(struct > ppp_idle64)))) > return r; > } > break; > diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c > index 3a7aa2eed415..c8b8aa071140 100644 > --- a/drivers/net/ppp/ppp_generic.c > +++ b/drivers/net/ppp/ppp_generic.c > @@ -619,7 +619,8 @@ static long ppp_ioctl(struct file *file, unsigned int > cmd, unsigned long arg) > struct ppp_file *pf; > struct ppp *ppp; > int err = -EFAULT, val, val2, i; > - struct ppp_idle idle; > + struct ppp_idle32 idle32; > + struct ppp_idle64 idle64; > struct npioctl npi; > int unit, cflags; > struct slcompress *vj; > @@ -743,10 +744,17 @@ static long ppp_ioctl(struct file *file, unsigned int > cmd, unsigned long arg) > err = 0; > break; > > - case PPPIOCGIDLE: > - idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ; > - idle.recv_idle = (jiffies - ppp->last_recv) / HZ; > - if (copy_to_user(argp, &idle, sizeof(idle))) > + case PPPIOCGIDLE32: > + idle32.xmit_idle = (jiffies - ppp->last_xmit) / HZ; > + idle32.recv_idle = (jiffies - ppp->last_recv) / HZ; > + if (copy_to_user(argp, &idle32, sizeof(idle32))) > Missing 'break;'
> + err = 0; > + break; > + > + case PPPIOCGIDLE64: > + idle64.xmit_idle = (jiffies - ppp->last_xmit) / HZ; > + idle64.recv_idle = (jiffies - ppp->last_recv) / HZ; > + if (copy_to_user(argp, &idle32, sizeof(idle32))) > I guess you meant 'idle64' instead of 'idle32'.
