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 arnd@arndb.de --- 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))) + 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))) break; err = 0; break; diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c index 258c6938e80a..208ff51f3ed9 100644 --- a/fs/compat_ioctl.c +++ b/fs/compat_ioctl.c @@ -377,36 +377,7 @@ static int sg_grt_trans(struct file *file, } return err; } -#endif /* CONFIG_BLOCK */ - -struct ppp_idle32 { - compat_time_t xmit_idle; - compat_time_t recv_idle; -}; -#define PPPIOCGIDLE32 _IOR('t', 63, struct ppp_idle32) - -static int ppp_gidle(struct file *file, unsigned int cmd, - struct ppp_idle32 __user *idle32) -{ - struct ppp_idle __user *idle; - __kernel_time_t xmit, recv; - int err; - - idle = compat_alloc_user_space(sizeof(*idle)); - - err = do_ioctl(file, PPPIOCGIDLE, (unsigned long) idle);
- if (!err) { - if (get_user(xmit, &idle->xmit_idle) || - get_user(recv, &idle->recv_idle) || - put_user(xmit, &idle32->xmit_idle) || - put_user(recv, &idle32->recv_idle)) - err = -EFAULT; - } - return err; -} - -#ifdef CONFIG_BLOCK struct mtget32 { compat_long_t mt_type; compat_long_t mt_resid; @@ -1182,8 +1153,6 @@ static long do_ioctl_trans(unsigned int cmd, void __user *argp = compat_ptr(arg);
switch (cmd) { - case PPPIOCGIDLE32: - return ppp_gidle(file, cmd, argp); #ifdef CONFIG_BLOCK case SG_IO: return sg_ioctl_trans(file, cmd, argp); diff --git a/include/uapi/linux/ppp-ioctl.h b/include/uapi/linux/ppp-ioctl.h index 88b5f9990320..7bd2a5a75348 100644 --- a/include/uapi/linux/ppp-ioctl.h +++ b/include/uapi/linux/ppp-ioctl.h @@ -104,6 +104,8 @@ struct pppol2tp_ioc_stats { #define PPPIOCGDEBUG _IOR('t', 65, int) /* Read debug level */ #define PPPIOCSDEBUG _IOW('t', 64, int) /* Set debug level */ #define PPPIOCGIDLE _IOR('t', 63, struct ppp_idle) /* get idle time */ +#define PPPIOCGIDLE32 _IOR('t', 63, struct ppp_idle32) /* 32-bit times */ +#define PPPIOCGIDLE64 _IOR('t', 63, struct ppp_idle64) /* 64-bit times */ #define PPPIOCNEWUNIT _IOWR('t', 62, int) /* create new ppp unit */ #define PPPIOCATTACH _IOW('t', 61, int) /* attach to ppp unit */ #define PPPIOCDETACH _IOW('t', 60, int) /* obsolete, do not use */ diff --git a/include/uapi/linux/ppp_defs.h b/include/uapi/linux/ppp_defs.h index fff51b91b409..0039fa39a358 100644 --- a/include/uapi/linux/ppp_defs.h +++ b/include/uapi/linux/ppp_defs.h @@ -142,10 +142,24 @@ struct ppp_comp_stats { /* * The following structure records the time in seconds since * the last NP packet was sent or received. + * + * Linux implements both 32-bit and 64-bit time_t versions + * for compatibility with user space that defines ppp_idle + * based on the libc time_t. */ struct ppp_idle { __kernel_time_t xmit_idle; /* time since last NP packet sent */ __kernel_time_t recv_idle; /* time since last NP packet received */ };
+struct ppp_idle32 { + __s32 xmit_idle; /* time since last NP packet sent */ + __s32 recv_idle; /* time since last NP packet received */ +}; + +struct ppp_idle64 { + __s64 xmit_idle; /* time since last NP packet sent */ + __s64 recv_idle; /* time since last NP packet received */ +}; + #endif /* _UAPI_PPP_DEFS_H_ */