Revision 0620fddb56dfaf0e1034eeb69d79c73b361debbf authored by Eric Biggers on 08 June 2017, 13:49:26 UTC, committed by James Morris on 09 June 2017, 03:29:48 UTC
While a 'struct key' itself normally does not contain sensitive information, Documentation/security/keys.txt actually encourages this: "Having a payload is not required; and the payload can, in fact, just be a value stored in the struct key itself." In case someone has taken this advice, or will take this advice in the future, zero the key structure before freeing it. We might as well, and as a bonus this could make it a bit more difficult for an adversary to determine which keys have recently been in use. This is safe because the key_jar cache does not use a constructor. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
1 parent ee618b4
tsacct.c
/*
* tsacct.c - System accounting over taskstats interface
*
* Copyright (C) Jay Lan, <jlan@sgi.com>
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include <linux/kernel.h>
#include <linux/sched/signal.h>
#include <linux/sched/mm.h>
#include <linux/sched/cputime.h>
#include <linux/tsacct_kern.h>
#include <linux/acct.h>
#include <linux/jiffies.h>
#include <linux/mm.h>
/*
* fill in basic accounting fields
*/
void bacct_add_tsk(struct user_namespace *user_ns,
struct pid_namespace *pid_ns,
struct taskstats *stats, struct task_struct *tsk)
{
const struct cred *tcred;
u64 utime, stime, utimescaled, stimescaled;
u64 delta;
BUILD_BUG_ON(TS_COMM_LEN < TASK_COMM_LEN);
/* calculate task elapsed time in nsec */
delta = ktime_get_ns() - tsk->start_time;
/* 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;
if (thread_group_leader(tsk)) {
stats->ac_exitcode = tsk->exit_code;
if (tsk->flags & PF_FORKNOEXEC)
stats->ac_flag |= AFORK;
}
if (tsk->flags & PF_SUPERPRIV)
stats->ac_flag |= ASU;
if (tsk->flags & PF_DUMPCORE)
stats->ac_flag |= ACORE;
if (tsk->flags & PF_SIGNALED)
stats->ac_flag |= AXSIG;
stats->ac_nice = task_nice(tsk);
stats->ac_sched = tsk->policy;
stats->ac_pid = task_pid_nr_ns(tsk, pid_ns);
rcu_read_lock();
tcred = __task_cred(tsk);
stats->ac_uid = from_kuid_munged(user_ns, tcred->uid);
stats->ac_gid = from_kgid_munged(user_ns, tcred->gid);
stats->ac_ppid = pid_alive(tsk) ?
task_tgid_nr_ns(rcu_dereference(tsk->real_parent), pid_ns) : 0;
rcu_read_unlock();
task_cputime(tsk, &utime, &stime);
stats->ac_utime = div_u64(utime, NSEC_PER_USEC);
stats->ac_stime = div_u64(stime, NSEC_PER_USEC);
task_cputime_scaled(tsk, &utimescaled, &stimescaled);
stats->ac_utimescaled = div_u64(utimescaled, NSEC_PER_USEC);
stats->ac_stimescaled = div_u64(stimescaled, NSEC_PER_USEC);
stats->ac_minflt = tsk->min_flt;
stats->ac_majflt = tsk->maj_flt;
strncpy(stats->ac_comm, tsk->comm, sizeof(stats->ac_comm));
}
#ifdef CONFIG_TASK_XACCT
#define KB 1024
#define MB (1024*KB)
#define KB_MASK (~(KB-1))
/*
* fill in extended accounting fields
*/
void xacct_add_tsk(struct taskstats *stats, struct task_struct *p)
{
struct mm_struct *mm;
/* convert pages-nsec/1024 to Mbyte-usec, see __acct_update_integrals */
stats->coremem = p->acct_rss_mem1 * PAGE_SIZE;
do_div(stats->coremem, 1000 * KB);
stats->virtmem = p->acct_vm_mem1 * PAGE_SIZE;
do_div(stats->virtmem, 1000 * KB);
mm = get_task_mm(p);
if (mm) {
/* adjust to KB unit */
stats->hiwater_rss = get_mm_hiwater_rss(mm) * PAGE_SIZE / KB;
stats->hiwater_vm = get_mm_hiwater_vm(mm) * PAGE_SIZE / KB;
mmput(mm);
}
stats->read_char = p->ioac.rchar & KB_MASK;
stats->write_char = p->ioac.wchar & KB_MASK;
stats->read_syscalls = p->ioac.syscr & KB_MASK;
stats->write_syscalls = p->ioac.syscw & KB_MASK;
#ifdef CONFIG_TASK_IO_ACCOUNTING
stats->read_bytes = p->ioac.read_bytes & KB_MASK;
stats->write_bytes = p->ioac.write_bytes & KB_MASK;
stats->cancelled_write_bytes = p->ioac.cancelled_write_bytes & KB_MASK;
#else
stats->read_bytes = 0;
stats->write_bytes = 0;
stats->cancelled_write_bytes = 0;
#endif
}
#undef KB
#undef MB
static void __acct_update_integrals(struct task_struct *tsk,
u64 utime, u64 stime)
{
u64 time, delta;
if (!likely(tsk->mm))
return;
time = stime + utime;
delta = time - tsk->acct_timexpd;
if (delta < TICK_NSEC)
return;
tsk->acct_timexpd = time;
/*
* Divide by 1024 to avoid overflow, and to avoid division.
* The final unit reported to userspace is Mbyte-usecs,
* the rest of the math is done in xacct_add_tsk.
*/
tsk->acct_rss_mem1 += delta * get_mm_rss(tsk->mm) >> 10;
tsk->acct_vm_mem1 += delta * tsk->mm->total_vm >> 10;
}
/**
* acct_update_integrals - update mm integral fields in task_struct
* @tsk: task_struct for accounting
*/
void acct_update_integrals(struct task_struct *tsk)
{
u64 utime, stime;
unsigned long flags;
local_irq_save(flags);
task_cputime(tsk, &utime, &stime);
__acct_update_integrals(tsk, utime, stime);
local_irq_restore(flags);
}
/**
* acct_account_cputime - update mm integral after cputime update
* @tsk: task_struct for accounting
*/
void acct_account_cputime(struct task_struct *tsk)
{
__acct_update_integrals(tsk, tsk->utime, tsk->stime);
}
/**
* acct_clear_integrals - clear the mm integral fields in task_struct
* @tsk: task_struct whose accounting fields are cleared
*/
void acct_clear_integrals(struct task_struct *tsk)
{
tsk->acct_timexpd = 0;
tsk->acct_rss_mem1 = 0;
tsk->acct_vm_mem1 = 0;
}
#endif
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