On 29.09.20 09:19, chensong wrote:
> Upstream has used timespec64 to replace timespec inside kernel and
> used __kernel_timespec to replace timespect in syscalls, therefore
> we must keep aligned with upstream.
>
> clock_settime is a point to get started at, it involves 2 parts:
> 1, syscall in ./include/trace/events/cobalt-posix.h for 64bits
> 2, compat syscall in kernel/cobalt/posix/syscall32.c for 32bits
> 3, define __kernel_timespec in wrapper.h for compatibility
>
> some new functions are implemented to keep the compatibility with
> other syscalls which haven't been handled yet and will be removed
> in the end of the work.
>
> Signed-off-by: chensong <[email protected]>
>
> CC: Jan Kiszka <[email protected]>
> CC: Henning Schild <[email protected]>
> ---
> include/cobalt/kernel/clock.h | 6 ++---
> include/cobalt/kernel/compat.h | 3 +++
> .../cobalt/include/asm-generic/xenomai/wrappers.h | 9 +++++++
> kernel/cobalt/posix/clock.c | 28
> +++++++++++++++++-----
> kernel/cobalt/posix/clock.h | 15 ++++++++++--
> kernel/cobalt/posix/compat.c | 11 +++++++++
> kernel/cobalt/posix/syscall32.c | 6 ++---
> kernel/cobalt/trace/cobalt-posix.h | 24 +++++++++++++++++--
> 8 files changed, 86 insertions(+), 16 deletions(-)
>
> diff --git a/include/cobalt/kernel/clock.h b/include/cobalt/kernel/clock.h
> index c26776a..cf9d5ec 100644
> --- a/include/cobalt/kernel/clock.h
> +++ b/include/cobalt/kernel/clock.h
> @@ -52,7 +52,7 @@ struct xnclock {
> xnticks_t (*read_raw)(struct xnclock *clock);
> xnticks_t (*read_monotonic)(struct xnclock *clock);
> int (*set_time)(struct xnclock *clock,
> - const struct timespec *ts);
> + const struct timespec64 *ts);
> xnsticks_t (*ns_to_ticks)(struct xnclock *clock,
> xnsticks_t ns);
> xnsticks_t (*ticks_to_ns)(struct xnclock *clock,
> @@ -213,7 +213,7 @@ static inline xnticks_t xnclock_read_monotonic(struct
> xnclock *clock)
> }
>
> static inline int xnclock_set_time(struct xnclock *clock,
> - const struct timespec *ts)
> + const struct timespec64 *ts)
> {
> if (likely(clock == &nkclock))
> return -EINVAL;
> @@ -266,7 +266,7 @@ static inline xnticks_t xnclock_read_monotonic(struct
> xnclock *clock)
> }
>
> static inline int xnclock_set_time(struct xnclock *clock,
> - const struct timespec *ts)
> + const struct timespec64 *ts)
> {
> /*
> * There is no way to change the core clock's idea of time.
> diff --git a/include/cobalt/kernel/compat.h b/include/cobalt/kernel/compat.h
> index 05754cb..70e2c03 100644
> --- a/include/cobalt/kernel/compat.h
> +++ b/include/cobalt/kernel/compat.h
> @@ -89,6 +89,9 @@ struct compat_rtdm_mmap_request {
> int sys32_get_timespec(struct timespec *ts,
> const struct compat_timespec __user *cts);
>
> +int sys64_get_timespec(struct timespec64 *ts,
> + const struct compat_timespec __user *cts);
> +
> int sys32_put_timespec(struct compat_timespec __user *cts,
> const struct timespec *ts);
>
> diff --git a/kernel/cobalt/include/asm-generic/xenomai/wrappers.h
> b/kernel/cobalt/include/asm-generic/xenomai/wrappers.h
> index 23993dc..e5375de 100644
> --- a/kernel/cobalt/include/asm-generic/xenomai/wrappers.h
> +++ b/kernel/cobalt/include/asm-generic/xenomai/wrappers.h
> @@ -156,4 +156,13 @@ devm_hwmon_device_register_with_groups(struct device
> *dev, const char *name,
> #error "Xenomai/cobalt requires Linux kernel 3.10 or above"
> #endif /* < 3.10 */
>
> +#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 18, 0)
> +typedef long long __kernel_time64_t;
> +struct __kernel_timespec {
> + __kernel_time64_t tv_sec; /* seconds */
> + long long tv_nsec; /* nanoseconds */
> +};
> +#endif /* < 4.18 */
> +
> +
> #endif /* _COBALT_ASM_GENERIC_WRAPPERS_H */
> diff --git a/kernel/cobalt/posix/clock.c b/kernel/cobalt/posix/clock.c
> index 561358e..c960d7b 100644
> --- a/kernel/cobalt/posix/clock.c
> +++ b/kernel/cobalt/posix/clock.c
> @@ -194,7 +194,7 @@ COBALT_SYSCALL(clock_gettime, current,
> return 0;
> }
>
> -int __cobalt_clock_settime(clockid_t clock_id, const struct timespec *ts)
> +int __cobalt_clock_settime(clockid_t clock_id, const struct timespec64 *ts)
> {
> int _ret, ret = 0;
> xnticks_t now;
> @@ -207,7 +207,7 @@ int __cobalt_clock_settime(clockid_t clock_id, const
> struct timespec *ts)
> case CLOCK_REALTIME:
> xnlock_get_irqsave(&nklock, s);
> now = xnclock_read_realtime(&nkclock);
> - xnclock_adjust(&nkclock, (xnsticks_t) (ts2ns(ts) - now));
> + xnclock_adjust(&nkclock, (xnsticks_t) (ts2ns64(ts) - now));
> xnlock_put_irqrestore(&nklock, s);
> break;
> default:
> @@ -242,15 +242,31 @@ int __cobalt_clock_adjtime(clockid_t clock_id, struct
> timex *tx)
> return 0;
> }
>
> +static int __cobalt_get_timespec64(struct timespec64 *ts,
> + const struct __kernel_timespec __user *uts)
> +{
> + struct __kernel_timespec kts;
> + int ret;
> +
> + ret = cobalt_copy_from_user(&kts, uts, sizeof(kts));
> + if (ret)
> + return -EFAULT;
> +
> + ts->tv_sec = kts.tv_sec;
> + ts->tv_nsec = kts.tv_nsec;
> +
> + return 0;
> +
> +}
> COBALT_SYSCALL(clock_settime, current,
> - (clockid_t clock_id, const struct timespec __user *u_ts))
> + (clockid_t clock_id, const struct __kernel_timespec __user *u_ts))
This is still a point where I see ABI breakage: On a 32-bit system,
struct timespec was using a 32-bit tv_sec. Now with struct
_kernel_timespec, this will become a 64-bit value. That is what we want
for new applications being built after this patch. However, existing
application - and that includes existing Xenomai libs built before this
change (stable kernel ABI...) will continue to deliver 32-bit tv_sec
here and break over this syscall change.
To model such a change in an ABI-preserving way, we need some
"clock_settime64" syscall that new userspace will pick by default, and
an unmodified (those 2038-wise broken) clock_settime. Same for all other
syscalls and drivers taking time_t directly or indirectly.
Jan
> {
> - struct timespec ts;
> + struct timespec64 new_ts;
>
> - if (cobalt_copy_from_user(&ts, u_ts, sizeof(ts)))
> + if (__cobalt_get_timespec64(&new_ts, u_ts))
> return -EFAULT;
>
> - return __cobalt_clock_settime(clock_id, &ts);
> + return __cobalt_clock_settime(clock_id, &new_ts);
> }
>
> COBALT_SYSCALL(clock_adjtime, current,
> diff --git a/kernel/cobalt/posix/clock.h b/kernel/cobalt/posix/clock.h
> index 0b06b93..d7328b0 100644
> --- a/kernel/cobalt/posix/clock.h
> +++ b/kernel/cobalt/posix/clock.h
> @@ -43,6 +43,16 @@ static inline xnticks_t ts2ns(const struct timespec *ts)
> return nsecs;
> }
>
> +static inline xnticks_t ts2ns64(const struct timespec64 *ts)
> +{
> + xnticks_t nsecs = ts->tv_nsec;
> +
> + if (ts->tv_sec)
> + nsecs += (xnticks_t)ts->tv_sec * ONE_BILLION;
> +
> + return nsecs;
> +}
> +
> static inline xnticks_t tv2ns(const struct timeval *tv)
> {
> xnticks_t nsecs = tv->tv_usec * 1000;
> @@ -86,7 +96,7 @@ int __cobalt_clock_gettime(clockid_t clock_id,
> struct timespec *ts);
>
> int __cobalt_clock_settime(clockid_t clock_id,
> - const struct timespec *ts);
> + const struct timespec64 *ts);
>
> int __cobalt_clock_adjtime(clockid_t clock_id,
> struct timex *tx);
> @@ -102,7 +112,8 @@ COBALT_SYSCALL_DECL(clock_gettime,
> (clockid_t clock_id, struct timespec __user *u_ts));
>
> COBALT_SYSCALL_DECL(clock_settime,
> - (clockid_t clock_id, const struct timespec __user *u_ts));
> + (clockid_t clock_id,
> + const struct __kernel_timespec __user *u_ts));
>
> COBALT_SYSCALL_DECL(clock_adjtime,
> (clockid_t clock_id, struct timex __user *u_tx));
> diff --git a/kernel/cobalt/posix/compat.c b/kernel/cobalt/posix/compat.c
> index 17968bf..08aedcf 100644
> --- a/kernel/cobalt/posix/compat.c
> +++ b/kernel/cobalt/posix/compat.c
> @@ -32,6 +32,17 @@ int sys32_get_timespec(struct timespec *ts,
> }
> EXPORT_SYMBOL_GPL(sys32_get_timespec);
>
> +int sys64_get_timespec(struct timespec64 *ts,
> + const struct compat_timespec __user *cts)
> +{
> + return (cts == NULL ||
> + !access_rok(cts, sizeof(*cts)) ||
> + __xn_get_user(ts->tv_sec, &cts->tv_sec) ||
> + __xn_get_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
> +}
> +EXPORT_SYMBOL_GPL(sys64_get_timespec);
> +
> +
> int sys32_put_timespec(struct compat_timespec __user *cts,
> const struct timespec *ts)
> {
> diff --git a/kernel/cobalt/posix/syscall32.c b/kernel/cobalt/posix/syscall32.c
> index faa7ef5..4b1dfcc 100644
> --- a/kernel/cobalt/posix/syscall32.c
> +++ b/kernel/cobalt/posix/syscall32.c
> @@ -161,14 +161,14 @@ COBALT_SYSCALL32emu(clock_settime, current,
> (clockid_t clock_id,
> const struct compat_timespec __user *u_ts))
> {
> - struct timespec ts;
> + struct timespec64 new_ts;
> int ret;
>
> - ret = sys32_get_timespec(&ts, u_ts);
> + ret = sys64_get_timespec(&new_ts, u_ts);
> if (ret)
> return ret;
>
> - return __cobalt_clock_settime(clock_id, &ts);
> + return __cobalt_clock_settime(clock_id, &new_ts);
> }
>
> COBALT_SYSCALL32emu(clock_adjtime, current,
> diff --git a/kernel/cobalt/trace/cobalt-posix.h
> b/kernel/cobalt/trace/cobalt-posix.h
> index aa78efb..f764872 100644
> --- a/kernel/cobalt/trace/cobalt-posix.h
> +++ b/kernel/cobalt/trace/cobalt-posix.h
> @@ -748,6 +748,26 @@ DECLARE_EVENT_CLASS(cobalt_clock_timespec,
> )
> );
>
> +DECLARE_EVENT_CLASS(cobalt_clock_timespec64,
> + TP_PROTO(clockid_t clk_id, const struct timespec64 *val),
> + TP_ARGS(clk_id, val),
> +
> + TP_STRUCT__entry(
> + __field(clockid_t, clk_id)
> + __timespec_fields(val)
> + ),
> +
> + TP_fast_assign(
> + __entry->clk_id = clk_id;
> + __assign_timespec(val, val);
> + ),
> +
> + TP_printk("clock_id=%d timeval=(%ld.%09ld)",
> + __entry->clk_id,
> + __timespec_args(val)
> + )
> +);
> +
> DEFINE_EVENT(cobalt_clock_timespec, cobalt_clock_getres,
> TP_PROTO(clockid_t clk_id, const struct timespec *res),
> TP_ARGS(clk_id, res)
> @@ -758,8 +778,8 @@ DEFINE_EVENT(cobalt_clock_timespec, cobalt_clock_gettime,
> TP_ARGS(clk_id, time)
> );
>
> -DEFINE_EVENT(cobalt_clock_timespec, cobalt_clock_settime,
> - TP_PROTO(clockid_t clk_id, const struct timespec *time),
> +DEFINE_EVENT(cobalt_clock_timespec64, cobalt_clock_settime,
> + TP_PROTO(clockid_t clk_id, const struct timespec64 *time),
> TP_ARGS(clk_id, time)
> );
>
>
--
Siemens AG, T RDA IOT
Corporate Competence Center Embedded Linux
