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authorLinus Torvalds <torvalds@linux-foundation.org>2020-12-15 03:35:39 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2020-12-15 03:35:39 +0300
commit6d93a1971a0ded67887eeab8d00a02074490f071 (patch)
tree7dc6494bde2dec7fc2ddf6ef4bd09f8d5778757e /fs/proc
parent0ca2ce81eb8ee30f3ba8ac7967fef9cfbb44dbdb (diff)
parent5c62634fc65101d350cbd47722fb76f02693059d (diff)
downloadlinux-6d93a1971a0ded67887eeab8d00a02074490f071.tar.xz
Merge tag 'time-namespace-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux
Pull time namespace updates from Christian Brauner: "When time namespaces were introduced we missed to virtualize the 'btime' field in /proc/stat. This confuses tasks which are in another time namespace with a virtualized boottime which is common in some container workloads. This contains Michael's series to fix 'btime' which Thomas asked me to take through my tree. To fix 'btime' virtualization we simply subtract the offset of the time namespace's boottime from btime before printing the stats. Note that since start_boottime of processes are seconds since boottime and the boottime stamp is now shifted according to the time namespace's offset, the offset of the time namespace also needs to be applied before the process stats are given to userspace. This avoids that processes shown by tools such as 'ps' appear as time travelers in the corresponding time namespace. Selftests are included to verify that btime virtualization in /proc/stat works as expected" * tag 'time-namespace-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: namespace: make timens_on_fork() return nothing selftests/timens: added selftest for /proc/stat btime fs/proc: apply the time namespace offset to /proc/stat btime timens: additional helper functions for boottime offset handling
Diffstat (limited to 'fs/proc')
-rw-r--r--fs/proc/array.c6
-rw-r--r--fs/proc/stat.c3
2 files changed, 7 insertions, 2 deletions
diff --git a/fs/proc/array.c b/fs/proc/array.c
index 65ec2029fa80..277f654f289e 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -56,6 +56,7 @@
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/time.h>
+#include <linux/time_namespace.h>
#include <linux/kernel.h>
#include <linux/kernel_stat.h>
#include <linux/tty.h>
@@ -533,8 +534,9 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
priority = task_prio(task);
nice = task_nice(task);
- /* convert nsec -> ticks */
- start_time = nsec_to_clock_t(task->start_boottime);
+ /* apply timens offset for boottime and convert nsec -> ticks */
+ start_time =
+ nsec_to_clock_t(timens_add_boottime_ns(task->start_boottime));
seq_put_decimal_ull(m, "", pid_nr_ns(pid, ns));
seq_puts(m, " (");
diff --git a/fs/proc/stat.c b/fs/proc/stat.c
index 4695b6de3151..f25e8531fd27 100644
--- a/fs/proc/stat.c
+++ b/fs/proc/stat.c
@@ -10,6 +10,7 @@
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/time.h>
+#include <linux/time_namespace.h>
#include <linux/irqnr.h>
#include <linux/sched/cputime.h>
#include <linux/tick.h>
@@ -118,6 +119,8 @@ static int show_stat(struct seq_file *p, void *v)
irq = softirq = steal = 0;
guest = guest_nice = 0;
getboottime64(&boottime);
+ /* shift boot timestamp according to the timens offset */
+ timens_sub_boottime(&boottime);
for_each_possible_cpu(i) {
struct kernel_cpustat kcpustat;