From: Dmitry Safonov <dima@arista.com> To: linux-kernel@vger.kernel.org Cc: Dmitry Safonov <0x7f454c46@gmail.com>, Andrei Vagin <avagin@gmail.com>, Dmitry Safonov <dima@arista.com>, Adrian Reber <adrian@lisas.de>, Andrei Vagin <avagin@openvz.org>, Andy Lutomirski <luto@kernel.org>, Arnd Bergmann <arnd@arndb.de>, Christian Brauner <christian.brauner@ubuntu.com>, Cyrill Gorcunov <gorcunov@openvz.org>, "Eric W. Biederman" <ebiederm@xmission.com>, "H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@redhat.com>, Jann Horn <jannh@google.com>, Jeff Dike <jdike@addtoit.com>, Oleg Nesterov <oleg@redhat.com>, Pavel Emelyanov <xemul@virtuozzo.com>, Shuah Khan <shuah@kernel.org>, Thomas Gleixner <tglx@linutronix.de>, Vincenzo Frascino <vincenzo.frascino@arm.com>, containers@lists.linux-foundation.org, criu@openvz.org, linux-api@vger.kernel.org, x86@kernel.org Subject: [PATCHv5 11/37] kernel: Add do_timens_ktime_to_host() helper Date: Mon, 29 Jul 2019 22:56:53 +0100 [thread overview] Message-ID: <20190729215758.28405-12-dima@arista.com> (raw) In-Reply-To: <20190729215758.28405-1-dima@arista.com> From: Andrei Vagin <avagin@gmail.com> The helper subtracts namespace's clock offset from the given time and checks that the result is in [0, KTIME_MAX]. Signed-off-by: Andrei Vagin <avagin@gmail.com> Co-developed-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Dmitry Safonov <dima@arista.com> --- include/linux/time_namespace.h | 17 ++++++++++++++ kernel/time_namespace.c | 43 ++++++++++++++++++++++++++++++++++ 2 files changed, 60 insertions(+) diff --git a/include/linux/time_namespace.h b/include/linux/time_namespace.h index 334c1a1c6607..9ba9664ff0ab 100644 --- a/include/linux/time_namespace.h +++ b/include/linux/time_namespace.h @@ -56,6 +56,18 @@ static inline void timens_add_boottime(struct timespec64 *ts) *ts = timespec64_add(*ts, ns_offsets->boottime); } +ktime_t do_timens_ktime_to_host(clockid_t clockid, ktime_t tim, + struct timens_offsets *offsets); +static inline ktime_t timens_ktime_to_host(clockid_t clockid, ktime_t tim) +{ + struct timens_offsets *offsets = current->nsproxy->time_ns->offsets; + + if (!offsets) + return tim; + + return do_timens_ktime_to_host(clockid, tim, offsets); +} + #else static inline struct time_namespace *get_time_ns(struct time_namespace *ns) { @@ -82,6 +94,11 @@ static inline int timens_on_fork(struct nsproxy *nsproxy, struct task_struct *ts static inline void timens_add_monotonic(struct timespec64 *ts) {} static inline void timens_add_boottime(struct timespec64 *ts) {} + +static inline ktime_t timens_ktime_to_host(clockid_t clockid, ktime_t tim) +{ + return tim; +} #endif #endif /* _LINUX_TIMENS_H */ diff --git a/kernel/time_namespace.c b/kernel/time_namespace.c index f849c59f1108..9807c5c90cb2 100644 --- a/kernel/time_namespace.c +++ b/kernel/time_namespace.c @@ -16,6 +16,49 @@ #include <linux/err.h> #include <linux/mm.h> +ktime_t do_timens_ktime_to_host(clockid_t clockid, ktime_t tim, + struct timens_offsets *ns_offsets) +{ + ktime_t offset; + + switch (clockid) { + case CLOCK_MONOTONIC: + offset = timespec64_to_ktime(ns_offsets->monotonic); + break; + case CLOCK_BOOTTIME: + case CLOCK_BOOTTIME_ALARM: + offset = timespec64_to_ktime(ns_offsets->boottime); + break; + default: + return tim; + } + + /* + * Check that @tim value is in [offset, KTIME_MAX + offset] + * and subtract offset. + */ + if (tim < offset) { + /* + * User can specify @tim *absolute* value - if it's lesser than + * the time namespace's offset - it's already expired. + */ + tim = 0; + } else if (KTIME_MAX - tim < -offset) { + /* + * User-supplied @tim may be close or even equal KTIME_MAX + * and time namespace offset can be negative. + * Let's check (tim - offset) for an overflow. + * Return KTIME_MAX in such case, as the time value is + * thousands *years* in future anyway. + */ + tim = KTIME_MAX; + } else { + tim = ktime_sub(tim, offset); + } + + return tim; +} + static struct ucounts *inc_time_namespaces(struct user_namespace *ns) { return inc_ucount(ns, current_euid(), UCOUNT_TIME_NAMESPACES); -- 2.22.0
WARNING: multiple messages have this Message-ID (diff)
From: Dmitry Safonov <dima@arista.com> To: linux-kernel@vger.kernel.org Cc: Dmitry Safonov <0x7f454c46@gmail.com>, Andrei Vagin <avagin@gmail.com>, Dmitry Safonov <dima@arista.com>, Adrian Reber <adrian@lisas.de>, Andrei Vagin <avagin@openvz.org>, Andy Lutomirski <luto@kernel.org>, Arnd Bergmann <arnd@arndb.de>, Christian Brauner <christian.brauner@ubuntu.com>, Cyrill Gorcunov <gorcunov@openvz.org>, "Eric W. Biederman" <ebiederm@xmission.com>, "H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@redhat.com>, Jann Horn <jannh@google.com>, Jeff Dike <jdike@addtoit.com>, Oleg Nesterov <oleg@redhat.com>, Pavel Emelyanov <xemul@virtuozzo.com>, Shuah Khan <shuah@kernel.org>, Thomas Gleixner <tglx@linutronix.de>, Vincenzo Frascino <vincenzo.frascino@arm.com>, containers@lists.linux-foundation.org, criu@openvz.org, linux-api Subject: [PATCHv5 11/37] kernel: Add do_timens_ktime_to_host() helper Date: Mon, 29 Jul 2019 22:56:53 +0100 [thread overview] Message-ID: <20190729215758.28405-12-dima@arista.com> (raw) In-Reply-To: <20190729215758.28405-1-dima@arista.com> From: Andrei Vagin <avagin@gmail.com> The helper subtracts namespace's clock offset from the given time and checks that the result is in [0, KTIME_MAX]. Signed-off-by: Andrei Vagin <avagin@gmail.com> Co-developed-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Dmitry Safonov <dima@arista.com> --- include/linux/time_namespace.h | 17 ++++++++++++++ kernel/time_namespace.c | 43 ++++++++++++++++++++++++++++++++++ 2 files changed, 60 insertions(+) diff --git a/include/linux/time_namespace.h b/include/linux/time_namespace.h index 334c1a1c6607..9ba9664ff0ab 100644 --- a/include/linux/time_namespace.h +++ b/include/linux/time_namespace.h @@ -56,6 +56,18 @@ static inline void timens_add_boottime(struct timespec64 *ts) *ts = timespec64_add(*ts, ns_offsets->boottime); } +ktime_t do_timens_ktime_to_host(clockid_t clockid, ktime_t tim, + struct timens_offsets *offsets); +static inline ktime_t timens_ktime_to_host(clockid_t clockid, ktime_t tim) +{ + struct timens_offsets *offsets = current->nsproxy->time_ns->offsets; + + if (!offsets) + return tim; + + return do_timens_ktime_to_host(clockid, tim, offsets); +} + #else static inline struct time_namespace *get_time_ns(struct time_namespace *ns) { @@ -82,6 +94,11 @@ static inline int timens_on_fork(struct nsproxy *nsproxy, struct task_struct *ts static inline void timens_add_monotonic(struct timespec64 *ts) {} static inline void timens_add_boottime(struct timespec64 *ts) {} + +static inline ktime_t timens_ktime_to_host(clockid_t clockid, ktime_t tim) +{ + return tim; +} #endif #endif /* _LINUX_TIMENS_H */ diff --git a/kernel/time_namespace.c b/kernel/time_namespace.c index f849c59f1108..9807c5c90cb2 100644 --- a/kernel/time_namespace.c +++ b/kernel/time_namespace.c @@ -16,6 +16,49 @@ #include <linux/err.h> #include <linux/mm.h> +ktime_t do_timens_ktime_to_host(clockid_t clockid, ktime_t tim, + struct timens_offsets *ns_offsets) +{ + ktime_t offset; + + switch (clockid) { + case CLOCK_MONOTONIC: + offset = timespec64_to_ktime(ns_offsets->monotonic); + break; + case CLOCK_BOOTTIME: + case CLOCK_BOOTTIME_ALARM: + offset = timespec64_to_ktime(ns_offsets->boottime); + break; + default: + return tim; + } + + /* + * Check that @tim value is in [offset, KTIME_MAX + offset] + * and subtract offset. + */ + if (tim < offset) { + /* + * User can specify @tim *absolute* value - if it's lesser than + * the time namespace's offset - it's already expired. + */ + tim = 0; + } else if (KTIME_MAX - tim < -offset) { + /* + * User-supplied @tim may be close or even equal KTIME_MAX + * and time namespace offset can be negative. + * Let's check (tim - offset) for an overflow. + * Return KTIME_MAX in such case, as the time value is + * thousands *years* in future anyway. + */ + tim = KTIME_MAX; + } else { + tim = ktime_sub(tim, offset); + } + + return tim; +} + static struct ucounts *inc_time_namespaces(struct user_namespace *ns) { return inc_ucount(ns, current_euid(), UCOUNT_TIME_NAMESPACES); -- 2.22.0
next prev parent reply other threads:[~2019-07-29 22:01 UTC|newest] Thread overview: 112+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-07-29 21:56 [PATCHv5 00/37] kernel: Introduce Time Namespace Dmitry Safonov 2019-07-29 21:56 ` Dmitry Safonov 2019-07-29 21:56 ` [PATCHv5 01/37] ns: " Dmitry Safonov 2019-08-01 5:29 ` Andy Lutomirski 2019-08-01 5:29 ` Andy Lutomirski 2019-08-01 23:46 ` Dmitry Safonov 2019-08-07 0:24 ` [PATCHv6 " Dmitry Safonov 2019-07-29 21:56 ` [PATCHv5 02/37] timens: Add timens_offsets Dmitry Safonov 2019-07-29 21:56 ` [PATCHv5 03/37] posix-clocks: Rename the clock_get() into clock_get_timespec() Dmitry Safonov 2019-07-29 21:56 ` Dmitry Safonov 2019-07-29 21:56 ` [PATCHv5 04/37] posix-clocks: Rename *_clock_get() functions into *_clock_get_timespec() Dmitry Safonov 2019-07-29 21:56 ` Dmitry Safonov 2019-08-07 6:01 ` Thomas Gleixner 2019-07-29 21:56 ` [PATCHv5 05/37] alarmtimer: Rename gettime() callback to get_ktime() Dmitry Safonov 2019-07-29 21:56 ` Dmitry Safonov 2019-07-29 21:56 ` [PATCHv5 06/37] alarmtimer: Provide get_timespec() callback Dmitry Safonov 2019-07-29 21:56 ` Dmitry Safonov 2019-08-07 6:04 ` Thomas Gleixner 2019-08-08 6:18 ` Andrei Vagin 2019-07-29 21:56 ` [PATCHv5 07/37] posix-clocks: Introduce clock_get_ktime() callback Dmitry Safonov 2019-07-29 21:56 ` Dmitry Safonov 2019-07-29 21:56 ` [PATCHv5 08/37] posix-timers: Use clock_get_ktime() in common_timer_get() Dmitry Safonov 2019-07-29 21:56 ` Dmitry Safonov 2019-07-29 21:56 ` [PATCHv5 09/37] posix-clocks: Introduce CLOCK_MONOTONIC time namespace offsets Dmitry Safonov 2019-08-07 6:07 ` Thomas Gleixner 2019-07-29 21:56 ` [PATCHv5 10/37] posix-clocks: Introduce CLOCK_BOOTTIME time namespace offset Dmitry Safonov 2019-07-29 21:56 ` Dmitry Safonov 2019-07-29 21:56 ` Dmitry Safonov [this message] 2019-07-29 21:56 ` [PATCHv5 11/37] kernel: Add do_timens_ktime_to_host() helper Dmitry Safonov 2019-07-29 21:56 ` [PATCHv5 12/37] timerfd: Make timerfd_settime() time namespace aware Dmitry Safonov 2019-07-29 21:56 ` Dmitry Safonov 2019-07-29 21:56 ` [PATCHv5 13/37] posix-timers: Make timer_settime() " Dmitry Safonov 2019-07-29 21:56 ` Dmitry Safonov 2019-07-29 21:56 ` [PATCHv5 14/37] alarmtimer: Make nanosleep " Dmitry Safonov 2019-07-29 21:56 ` Dmitry Safonov 2019-07-29 21:56 ` [PATCHv5 15/37] hrtimers: Prepare hrtimer_nanosleep() for time namespaces Dmitry Safonov 2019-07-29 21:56 ` Dmitry Safonov 2019-07-29 21:56 ` [PATCHv5 16/37] posix-timers: Make clock_nanosleep() time namespace aware Dmitry Safonov 2019-07-29 21:56 ` Dmitry Safonov 2019-07-29 21:56 ` [PATCHv5 17/37] fd/proc: Respect boottime inside time namespace for /proc/uptime Dmitry Safonov 2019-07-29 21:57 ` [PATCHv5 18/37] x86/vdso2c: Correct err messages on file opening Dmitry Safonov 2019-07-29 21:57 ` [PATCHv5 19/37] x86/vdso2c: Convert iterator to unsigned Dmitry Safonov 2019-07-29 21:57 ` [PATCHv5 20/37] x86/vdso/Makefile: Add vobjs32 Dmitry Safonov 2019-07-29 21:57 ` [PATCHv5 21/37] x86/vdso: Restrict splitting VVAR VMA Dmitry Safonov 2019-08-01 5:23 ` Andy Lutomirski 2019-08-01 5:23 ` Andy Lutomirski 2019-07-29 21:57 ` [PATCHv5 22/37] x86/vdso: Rename vdso_image {.data=>.text} Dmitry Safonov 2019-07-29 21:57 ` [PATCHv5 23/37] x86/vdso: Add offsets page in vvar Dmitry Safonov 2019-07-29 21:57 ` Dmitry Safonov 2019-08-01 5:22 ` Andy Lutomirski 2019-08-01 5:22 ` Andy Lutomirski 2019-07-29 21:57 ` [PATCHv5 24/37] x86/vdso: Allocate timens vdso Dmitry Safonov 2019-07-29 21:57 ` [PATCHv5 25/37] x86/vdso: Switch image on setns()/clone() Dmitry Safonov 2019-07-29 21:57 ` Dmitry Safonov 2019-08-01 5:34 ` Andy Lutomirski 2019-08-01 5:34 ` Andy Lutomirski 2019-08-01 6:09 ` hpa 2019-08-01 21:39 ` Andy Lutomirski 2019-08-01 21:39 ` Andy Lutomirski 2019-08-07 0:27 ` [PATCHv6 " Dmitry Safonov 2019-07-29 21:57 ` [PATCHv5 26/37] vdso: Introduce vdso_static_branch_unlikely() Dmitry Safonov 2019-07-29 21:57 ` Dmitry Safonov 2019-07-29 21:57 ` [PATCHv5 27/37] x86/vdso2c: Process jump tables Dmitry Safonov 2019-07-29 21:57 ` Dmitry Safonov 2019-07-29 21:57 ` [PATCHv5 28/37] x86/vdso: Enable static branches for the timens vdso Dmitry Safonov 2019-07-29 21:57 ` Dmitry Safonov 2019-08-01 5:21 ` Andy Lutomirski 2019-08-01 5:21 ` Andy Lutomirski 2019-08-01 6:48 ` Thomas Gleixner 2019-08-01 6:48 ` Thomas Gleixner 2019-07-29 21:57 ` [PATCHv5 29/37] posix-clocks: Add align for timens_offsets Dmitry Safonov 2019-07-29 21:57 ` [PATCHv5 30/37] fs/proc: Introduce /proc/pid/timens_offsets Dmitry Safonov 2019-07-29 21:57 ` Dmitry Safonov 2019-07-29 21:57 ` [PATCHv5 31/37] selftest/timens: Add Time Namespace test for supported clocks Dmitry Safonov 2019-07-29 21:57 ` [PATCHv5 32/37] selftest/timens: Add a test for timerfd Dmitry Safonov 2019-07-29 21:57 ` Dmitry Safonov 2019-07-29 21:57 ` [PATCHv5 33/37] selftest/timens: Add a test for clock_nanosleep() Dmitry Safonov 2019-07-29 21:57 ` Dmitry Safonov 2019-07-29 21:57 ` [PATCHv5 34/37] selftest/timens: Add procfs selftest Dmitry Safonov 2019-07-29 21:57 ` Dmitry Safonov 2019-07-29 21:57 ` [PATCHv5 35/37] selftest/timens: Add timer offsets test Dmitry Safonov 2019-07-29 21:57 ` Dmitry Safonov 2019-07-29 21:57 ` [PATCHv5 36/37] selftests/timens: Add a simple perf test for clock_gettime() Dmitry Safonov 2019-07-29 21:57 ` Dmitry Safonov 2019-07-29 21:57 ` [PATCHv5 37/37] selftest/timens: Check that a right vdso is mapped after fork and exec Dmitry Safonov 2019-07-29 21:57 ` Dmitry Safonov 2019-07-29 21:57 ` [PATCHv5 00/37] kernel: Introduce Time Namespace Dmitry Safonov 2019-07-29 21:57 ` Dmitry Safonov 2019-07-29 22:07 ` Dmitry Safonov 2019-07-29 21:57 ` [PATCHv5 01/37] ns: " Dmitry Safonov 2019-07-29 21:57 ` [PATCHv5 02/37] timens: Add timens_offsets Dmitry Safonov 2019-07-29 21:57 ` [PATCHv5 03/37] posix-clocks: Rename the clock_get() into clock_get_timespec() Dmitry Safonov 2019-07-29 21:57 ` Dmitry Safonov 2019-07-29 21:57 ` [PATCHv5 04/37] posix-clocks: Rename *_clock_get() functions into *_clock_get_timespec() Dmitry Safonov 2019-07-29 21:57 ` Dmitry Safonov 2019-07-29 21:57 ` [PATCHv5 05/37] alarmtimer: Rename gettime() callback to get_ktime() Dmitry Safonov 2019-07-29 21:57 ` Dmitry Safonov 2019-07-29 21:57 ` [PATCHv5 06/37] alarmtimer: Provide get_timespec() callback Dmitry Safonov 2019-07-29 21:57 ` Dmitry Safonov 2019-07-29 21:57 ` [PATCHv5 07/37] posix-clocks: Introduce clock_get_ktime() callback Dmitry Safonov 2019-07-29 21:57 ` Dmitry Safonov 2019-07-29 21:57 ` [PATCHv5 08/37] posix-timers: Use clock_get_ktime() in common_timer_get() Dmitry Safonov 2019-07-29 21:57 ` Dmitry Safonov 2019-07-29 21:57 ` [PATCHv5 09/37] posix-clocks: Introduce CLOCK_MONOTONIC time namespace offsets Dmitry Safonov 2019-07-29 21:57 ` [PATCHv5 10/37] posix-clocks: Introduce CLOCK_BOOTTIME time namespace offset Dmitry Safonov 2019-07-29 21:57 ` Dmitry Safonov 2019-07-29 21:57 ` [PATCHv5 11/37] kernel: Add do_timens_ktime_to_host() helper Dmitry Safonov 2019-07-29 21:57 ` Dmitry Safonov 2019-07-29 21:57 ` [PATCHv5 12/37] timerfd: Make timerfd_settime() time namespace aware Dmitry Safonov 2019-07-29 21:57 ` Dmitry Safonov 2019-07-29 21:57 ` [PATCHv5 13/37] posix-timers: Make timer_settime() " Dmitry Safonov 2019-07-29 21:57 ` Dmitry Safonov
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