diff --git a/include/uapi/linux/acct.h b/include/uapi/linux/acct.h index 0e72172cd23a..985b89068591 100644 --- a/include/uapi/linux/acct.h +++ b/include/uapi/linux/acct.h @@ -49,6 +49,7 @@ struct acct __u16 ac_uid16; /* LSB of Real User ID */ __u16 ac_gid16; /* LSB of Real Group ID */ __u16 ac_tty; /* Control Terminal */ + /* __u32 range means times from 1970 to 2106 */ __u32 ac_btime; /* Process Creation Time */ comp_t ac_utime; /* User Time */ comp_t ac_stime; /* System Time */ @@ -81,6 +82,7 @@ struct acct_v3 __u32 ac_gid; /* Real Group ID */ __u32 ac_pid; /* Process ID */ __u32 ac_ppid; /* Parent Process ID */ + /* __u32 range means times from 1970 to 2106 */ __u32 ac_btime; /* Process Creation Time */ #ifdef __KERNEL__ __u32 ac_etime; /* Elapsed Time */ diff --git a/include/uapi/linux/taskstats.h b/include/uapi/linux/taskstats.h index 5e8ca16a9079..7d3ea366e93b 100644 --- a/include/uapi/linux/taskstats.h +++ b/include/uapi/linux/taskstats.h @@ -112,6 +112,7 @@ struct taskstats { __u32 ac_gid; /* Group ID */ __u32 ac_pid; /* Process ID */ __u32 ac_ppid; /* Parent process ID */ + /* __u32 range means times from 1970 to 2106 */ __u32 ac_btime; /* Begin time [sec since 1970] */ __u64 ac_etime __attribute__((aligned(8))); /* Elapsed time [usec] */ diff --git a/kernel/acct.c b/kernel/acct.c index 81f9831a7859..11ff4a596d6b 100644 --- a/kernel/acct.c +++ b/kernel/acct.c @@ -416,6 +416,7 @@ static void fill_ac(acct_t *ac) { struct pacct_struct *pacct = ¤t->signal->pacct; u64 elapsed, run_time; + time64_t btime; struct tty_struct *tty; /* @@ -448,7 +449,8 @@ static void fill_ac(acct_t *ac) } #endif do_div(elapsed, AHZ); - ac->ac_btime = get_seconds() - elapsed; + btime = ktime_get_real_seconds() - elapsed; + ac->ac_btime = clamp_t(time64_t, btime, 0, U32_MAX); #if ACCT_VERSION==2 ac->ac_ahz = AHZ; #endif diff --git a/kernel/tsacct.c b/kernel/tsacct.c index 7be3e7530841..ab12616ee6fb 100644 --- a/kernel/tsacct.c +++ b/kernel/tsacct.c @@ -24,6 +24,7 @@ void bacct_add_tsk(struct user_namespace *user_ns, const struct cred *tcred; u64 utime, stime, utimescaled, stimescaled; u64 delta; + time64_t btime; BUILD_BUG_ON(TS_COMM_LEN < TASK_COMM_LEN); @@ -32,9 +33,10 @@ void bacct_add_tsk(struct user_namespace *user_ns, /* Convert to micro seconds */ do_div(delta, NSEC_PER_USEC); stats->ac_etime = delta; - /* Convert to seconds for btime */ - do_div(delta, USEC_PER_SEC); - stats->ac_btime = get_seconds() - delta; + /* Convert to seconds for btime (note y2106 limit) */ + btime = ktime_get_real_seconds() - div_u64(delta, USEC_PER_SEC); + stats->ac_btime = clamp_t(time64_t, btime, 0, U32_MAX); + if (thread_group_leader(tsk)) { stats->ac_exitcode = tsk->exit_code; if (tsk->flags & PF_FORKNOEXEC)