mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-26 10:49:33 +00:00
![Zheng Yejian](/assets/img/avatar_default.png)
The integer overflow is descripted with following codes: > 317 static comp_t encode_comp_t(u64 value) > 318 { > 319 int exp, rnd; ...... > 341 exp <<= MANTSIZE; > 342 exp += value; > 343 return exp; > 344 } Currently comp_t is defined as type of '__u16', but the variable 'exp' is type of 'int', so overflow would happen when variable 'exp' in line 343 is greater than 65535. Link: https://lkml.kernel.org/r/20210515140631.369106-3-zhengyejian1@huawei.com Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com> Cc: Hanjun Guo <guohanjun@huawei.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zhang Jinhao <zhangjinhao2@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
623 lines
16 KiB
C
623 lines
16 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* linux/kernel/acct.c
|
|
*
|
|
* BSD Process Accounting for Linux
|
|
*
|
|
* Author: Marco van Wieringen <mvw@planets.elm.net>
|
|
*
|
|
* Some code based on ideas and code from:
|
|
* Thomas K. Dyas <tdyas@eden.rutgers.edu>
|
|
*
|
|
* This file implements BSD-style process accounting. Whenever any
|
|
* process exits, an accounting record of type "struct acct" is
|
|
* written to the file specified with the acct() system call. It is
|
|
* up to user-level programs to do useful things with the accounting
|
|
* log. The kernel just provides the raw accounting information.
|
|
*
|
|
* (C) Copyright 1995 - 1997 Marco van Wieringen - ELM Consultancy B.V.
|
|
*
|
|
* Plugged two leaks. 1) It didn't return acct_file into the free_filps if
|
|
* the file happened to be read-only. 2) If the accounting was suspended
|
|
* due to the lack of space it happily allowed to reopen it and completely
|
|
* lost the old acct_file. 3/10/98, Al Viro.
|
|
*
|
|
* Now we silently close acct_file on attempt to reopen. Cleaned sys_acct().
|
|
* XTerms and EMACS are manifestations of pure evil. 21/10/98, AV.
|
|
*
|
|
* Fixed a nasty interaction with sys_umount(). If the accounting
|
|
* was suspeneded we failed to stop it on umount(). Messy.
|
|
* Another one: remount to readonly didn't stop accounting.
|
|
* Question: what should we do if we have CAP_SYS_ADMIN but not
|
|
* CAP_SYS_PACCT? Current code does the following: umount returns -EBUSY
|
|
* unless we are messing with the root. In that case we are getting a
|
|
* real mess with do_remount_sb(). 9/11/98, AV.
|
|
*
|
|
* Fixed a bunch of races (and pair of leaks). Probably not the best way,
|
|
* but this one obviously doesn't introduce deadlocks. Later. BTW, found
|
|
* one race (and leak) in BSD implementation.
|
|
* OK, that's better. ANOTHER race and leak in BSD variant. There always
|
|
* is one more bug... 10/11/98, AV.
|
|
*
|
|
* Oh, fsck... Oopsable SMP race in do_process_acct() - we must hold
|
|
* ->mmap_lock to walk the vma list of current->mm. Nasty, since it leaks
|
|
* a struct file opened for write. Fixed. 2/6/2000, AV.
|
|
*/
|
|
|
|
#include <linux/mm.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/acct.h>
|
|
#include <linux/capability.h>
|
|
#include <linux/file.h>
|
|
#include <linux/tty.h>
|
|
#include <linux/security.h>
|
|
#include <linux/vfs.h>
|
|
#include <linux/jiffies.h>
|
|
#include <linux/times.h>
|
|
#include <linux/syscalls.h>
|
|
#include <linux/mount.h>
|
|
#include <linux/uaccess.h>
|
|
#include <linux/sched/cputime.h>
|
|
|
|
#include <asm/div64.h>
|
|
#include <linux/pid_namespace.h>
|
|
#include <linux/fs_pin.h>
|
|
|
|
/*
|
|
* These constants control the amount of freespace that suspend and
|
|
* resume the process accounting system, and the time delay between
|
|
* each check.
|
|
* Turned into sysctl-controllable parameters. AV, 12/11/98
|
|
*/
|
|
|
|
static int acct_parm[3] = {4, 2, 30};
|
|
#define RESUME (acct_parm[0]) /* >foo% free space - resume */
|
|
#define SUSPEND (acct_parm[1]) /* <foo% free space - suspend */
|
|
#define ACCT_TIMEOUT (acct_parm[2]) /* foo second timeout between checks */
|
|
|
|
#ifdef CONFIG_SYSCTL
|
|
static struct ctl_table kern_acct_table[] = {
|
|
{
|
|
.procname = "acct",
|
|
.data = &acct_parm,
|
|
.maxlen = 3*sizeof(int),
|
|
.mode = 0644,
|
|
.proc_handler = proc_dointvec,
|
|
},
|
|
{ }
|
|
};
|
|
|
|
static __init int kernel_acct_sysctls_init(void)
|
|
{
|
|
register_sysctl_init("kernel", kern_acct_table);
|
|
return 0;
|
|
}
|
|
late_initcall(kernel_acct_sysctls_init);
|
|
#endif /* CONFIG_SYSCTL */
|
|
|
|
/*
|
|
* External references and all of the globals.
|
|
*/
|
|
|
|
struct bsd_acct_struct {
|
|
struct fs_pin pin;
|
|
atomic_long_t count;
|
|
struct rcu_head rcu;
|
|
struct mutex lock;
|
|
int active;
|
|
unsigned long needcheck;
|
|
struct file *file;
|
|
struct pid_namespace *ns;
|
|
struct work_struct work;
|
|
struct completion done;
|
|
};
|
|
|
|
static void do_acct_process(struct bsd_acct_struct *acct);
|
|
|
|
/*
|
|
* Check the amount of free space and suspend/resume accordingly.
|
|
*/
|
|
static int check_free_space(struct bsd_acct_struct *acct)
|
|
{
|
|
struct kstatfs sbuf;
|
|
|
|
if (time_is_after_jiffies(acct->needcheck))
|
|
goto out;
|
|
|
|
/* May block */
|
|
if (vfs_statfs(&acct->file->f_path, &sbuf))
|
|
goto out;
|
|
|
|
if (acct->active) {
|
|
u64 suspend = sbuf.f_blocks * SUSPEND;
|
|
do_div(suspend, 100);
|
|
if (sbuf.f_bavail <= suspend) {
|
|
acct->active = 0;
|
|
pr_info("Process accounting paused\n");
|
|
}
|
|
} else {
|
|
u64 resume = sbuf.f_blocks * RESUME;
|
|
do_div(resume, 100);
|
|
if (sbuf.f_bavail >= resume) {
|
|
acct->active = 1;
|
|
pr_info("Process accounting resumed\n");
|
|
}
|
|
}
|
|
|
|
acct->needcheck = jiffies + ACCT_TIMEOUT*HZ;
|
|
out:
|
|
return acct->active;
|
|
}
|
|
|
|
static void acct_put(struct bsd_acct_struct *p)
|
|
{
|
|
if (atomic_long_dec_and_test(&p->count))
|
|
kfree_rcu(p, rcu);
|
|
}
|
|
|
|
static inline struct bsd_acct_struct *to_acct(struct fs_pin *p)
|
|
{
|
|
return p ? container_of(p, struct bsd_acct_struct, pin) : NULL;
|
|
}
|
|
|
|
static struct bsd_acct_struct *acct_get(struct pid_namespace *ns)
|
|
{
|
|
struct bsd_acct_struct *res;
|
|
again:
|
|
smp_rmb();
|
|
rcu_read_lock();
|
|
res = to_acct(READ_ONCE(ns->bacct));
|
|
if (!res) {
|
|
rcu_read_unlock();
|
|
return NULL;
|
|
}
|
|
if (!atomic_long_inc_not_zero(&res->count)) {
|
|
rcu_read_unlock();
|
|
cpu_relax();
|
|
goto again;
|
|
}
|
|
rcu_read_unlock();
|
|
mutex_lock(&res->lock);
|
|
if (res != to_acct(READ_ONCE(ns->bacct))) {
|
|
mutex_unlock(&res->lock);
|
|
acct_put(res);
|
|
goto again;
|
|
}
|
|
return res;
|
|
}
|
|
|
|
static void acct_pin_kill(struct fs_pin *pin)
|
|
{
|
|
struct bsd_acct_struct *acct = to_acct(pin);
|
|
mutex_lock(&acct->lock);
|
|
do_acct_process(acct);
|
|
schedule_work(&acct->work);
|
|
wait_for_completion(&acct->done);
|
|
cmpxchg(&acct->ns->bacct, pin, NULL);
|
|
mutex_unlock(&acct->lock);
|
|
pin_remove(pin);
|
|
acct_put(acct);
|
|
}
|
|
|
|
static void close_work(struct work_struct *work)
|
|
{
|
|
struct bsd_acct_struct *acct = container_of(work, struct bsd_acct_struct, work);
|
|
struct file *file = acct->file;
|
|
if (file->f_op->flush)
|
|
file->f_op->flush(file, NULL);
|
|
__fput_sync(file);
|
|
complete(&acct->done);
|
|
}
|
|
|
|
static int acct_on(struct filename *pathname)
|
|
{
|
|
struct file *file;
|
|
struct vfsmount *mnt, *internal;
|
|
struct pid_namespace *ns = task_active_pid_ns(current);
|
|
struct bsd_acct_struct *acct;
|
|
struct fs_pin *old;
|
|
int err;
|
|
|
|
acct = kzalloc(sizeof(struct bsd_acct_struct), GFP_KERNEL);
|
|
if (!acct)
|
|
return -ENOMEM;
|
|
|
|
/* Difference from BSD - they don't do O_APPEND */
|
|
file = file_open_name(pathname, O_WRONLY|O_APPEND|O_LARGEFILE, 0);
|
|
if (IS_ERR(file)) {
|
|
kfree(acct);
|
|
return PTR_ERR(file);
|
|
}
|
|
|
|
if (!S_ISREG(file_inode(file)->i_mode)) {
|
|
kfree(acct);
|
|
filp_close(file, NULL);
|
|
return -EACCES;
|
|
}
|
|
|
|
if (!(file->f_mode & FMODE_CAN_WRITE)) {
|
|
kfree(acct);
|
|
filp_close(file, NULL);
|
|
return -EIO;
|
|
}
|
|
internal = mnt_clone_internal(&file->f_path);
|
|
if (IS_ERR(internal)) {
|
|
kfree(acct);
|
|
filp_close(file, NULL);
|
|
return PTR_ERR(internal);
|
|
}
|
|
err = __mnt_want_write(internal);
|
|
if (err) {
|
|
mntput(internal);
|
|
kfree(acct);
|
|
filp_close(file, NULL);
|
|
return err;
|
|
}
|
|
mnt = file->f_path.mnt;
|
|
file->f_path.mnt = internal;
|
|
|
|
atomic_long_set(&acct->count, 1);
|
|
init_fs_pin(&acct->pin, acct_pin_kill);
|
|
acct->file = file;
|
|
acct->needcheck = jiffies;
|
|
acct->ns = ns;
|
|
mutex_init(&acct->lock);
|
|
INIT_WORK(&acct->work, close_work);
|
|
init_completion(&acct->done);
|
|
mutex_lock_nested(&acct->lock, 1); /* nobody has seen it yet */
|
|
pin_insert(&acct->pin, mnt);
|
|
|
|
rcu_read_lock();
|
|
old = xchg(&ns->bacct, &acct->pin);
|
|
mutex_unlock(&acct->lock);
|
|
pin_kill(old);
|
|
__mnt_drop_write(mnt);
|
|
mntput(mnt);
|
|
return 0;
|
|
}
|
|
|
|
static DEFINE_MUTEX(acct_on_mutex);
|
|
|
|
/**
|
|
* sys_acct - enable/disable process accounting
|
|
* @name: file name for accounting records or NULL to shutdown accounting
|
|
*
|
|
* sys_acct() is the only system call needed to implement process
|
|
* accounting. It takes the name of the file where accounting records
|
|
* should be written. If the filename is NULL, accounting will be
|
|
* shutdown.
|
|
*
|
|
* Returns: 0 for success or negative errno values for failure.
|
|
*/
|
|
SYSCALL_DEFINE1(acct, const char __user *, name)
|
|
{
|
|
int error = 0;
|
|
|
|
if (!capable(CAP_SYS_PACCT))
|
|
return -EPERM;
|
|
|
|
if (name) {
|
|
struct filename *tmp = getname(name);
|
|
|
|
if (IS_ERR(tmp))
|
|
return PTR_ERR(tmp);
|
|
mutex_lock(&acct_on_mutex);
|
|
error = acct_on(tmp);
|
|
mutex_unlock(&acct_on_mutex);
|
|
putname(tmp);
|
|
} else {
|
|
rcu_read_lock();
|
|
pin_kill(task_active_pid_ns(current)->bacct);
|
|
}
|
|
|
|
return error;
|
|
}
|
|
|
|
void acct_exit_ns(struct pid_namespace *ns)
|
|
{
|
|
rcu_read_lock();
|
|
pin_kill(ns->bacct);
|
|
}
|
|
|
|
/*
|
|
* encode an u64 into a comp_t
|
|
*
|
|
* This routine has been adopted from the encode_comp_t() function in
|
|
* the kern_acct.c file of the FreeBSD operating system. The encoding
|
|
* is a 13-bit fraction with a 3-bit (base 8) exponent.
|
|
*/
|
|
|
|
#define MANTSIZE 13 /* 13 bit mantissa. */
|
|
#define EXPSIZE 3 /* Base 8 (3 bit) exponent. */
|
|
#define MAXFRACT ((1 << MANTSIZE) - 1) /* Maximum fractional value. */
|
|
|
|
static comp_t encode_comp_t(u64 value)
|
|
{
|
|
int exp, rnd;
|
|
|
|
exp = rnd = 0;
|
|
while (value > MAXFRACT) {
|
|
rnd = value & (1 << (EXPSIZE - 1)); /* Round up? */
|
|
value >>= EXPSIZE; /* Base 8 exponent == 3 bit shift. */
|
|
exp++;
|
|
}
|
|
|
|
/*
|
|
* If we need to round up, do it (and handle overflow correctly).
|
|
*/
|
|
if (rnd && (++value > MAXFRACT)) {
|
|
value >>= EXPSIZE;
|
|
exp++;
|
|
}
|
|
|
|
if (exp > (((comp_t) ~0U) >> MANTSIZE))
|
|
return (comp_t) ~0U;
|
|
/*
|
|
* Clean it up and polish it off.
|
|
*/
|
|
exp <<= MANTSIZE; /* Shift the exponent into place */
|
|
exp += value; /* and add on the mantissa. */
|
|
return exp;
|
|
}
|
|
|
|
#if ACCT_VERSION == 1 || ACCT_VERSION == 2
|
|
/*
|
|
* encode an u64 into a comp2_t (24 bits)
|
|
*
|
|
* Format: 5 bit base 2 exponent, 20 bits mantissa.
|
|
* The leading bit of the mantissa is not stored, but implied for
|
|
* non-zero exponents.
|
|
* Largest encodable value is 50 bits.
|
|
*/
|
|
|
|
#define MANTSIZE2 20 /* 20 bit mantissa. */
|
|
#define EXPSIZE2 5 /* 5 bit base 2 exponent. */
|
|
#define MAXFRACT2 ((1ul << MANTSIZE2) - 1) /* Maximum fractional value. */
|
|
#define MAXEXP2 ((1 << EXPSIZE2) - 1) /* Maximum exponent. */
|
|
|
|
static comp2_t encode_comp2_t(u64 value)
|
|
{
|
|
int exp, rnd;
|
|
|
|
exp = (value > (MAXFRACT2>>1));
|
|
rnd = 0;
|
|
while (value > MAXFRACT2) {
|
|
rnd = value & 1;
|
|
value >>= 1;
|
|
exp++;
|
|
}
|
|
|
|
/*
|
|
* If we need to round up, do it (and handle overflow correctly).
|
|
*/
|
|
if (rnd && (++value > MAXFRACT2)) {
|
|
value >>= 1;
|
|
exp++;
|
|
}
|
|
|
|
if (exp > MAXEXP2) {
|
|
/* Overflow. Return largest representable number instead. */
|
|
return (1ul << (MANTSIZE2+EXPSIZE2-1)) - 1;
|
|
} else {
|
|
return (value & (MAXFRACT2>>1)) | (exp << (MANTSIZE2-1));
|
|
}
|
|
}
|
|
#elif ACCT_VERSION == 3
|
|
/*
|
|
* encode an u64 into a 32 bit IEEE float
|
|
*/
|
|
static u32 encode_float(u64 value)
|
|
{
|
|
unsigned exp = 190;
|
|
unsigned u;
|
|
|
|
if (value == 0)
|
|
return 0;
|
|
while ((s64)value > 0) {
|
|
value <<= 1;
|
|
exp--;
|
|
}
|
|
u = (u32)(value >> 40) & 0x7fffffu;
|
|
return u | (exp << 23);
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Write an accounting entry for an exiting process
|
|
*
|
|
* The acct_process() call is the workhorse of the process
|
|
* accounting system. The struct acct is built here and then written
|
|
* into the accounting file. This function should only be called from
|
|
* do_exit() or when switching to a different output file.
|
|
*/
|
|
|
|
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;
|
|
|
|
/*
|
|
* Fill the accounting struct with the needed info as recorded
|
|
* by the different kernel functions.
|
|
*/
|
|
memset(ac, 0, sizeof(acct_t));
|
|
|
|
ac->ac_version = ACCT_VERSION | ACCT_BYTEORDER;
|
|
strlcpy(ac->ac_comm, current->comm, sizeof(ac->ac_comm));
|
|
|
|
/* calculate run_time in nsec*/
|
|
run_time = ktime_get_ns();
|
|
run_time -= current->group_leader->start_time;
|
|
/* convert nsec -> AHZ */
|
|
elapsed = nsec_to_AHZ(run_time);
|
|
#if ACCT_VERSION == 3
|
|
ac->ac_etime = encode_float(elapsed);
|
|
#else
|
|
ac->ac_etime = encode_comp_t(elapsed < (unsigned long) -1l ?
|
|
(unsigned long) elapsed : (unsigned long) -1l);
|
|
#endif
|
|
#if ACCT_VERSION == 1 || ACCT_VERSION == 2
|
|
{
|
|
/* new enlarged etime field */
|
|
comp2_t etime = encode_comp2_t(elapsed);
|
|
|
|
ac->ac_etime_hi = etime >> 16;
|
|
ac->ac_etime_lo = (u16) etime;
|
|
}
|
|
#endif
|
|
do_div(elapsed, AHZ);
|
|
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
|
|
|
|
spin_lock_irq(¤t->sighand->siglock);
|
|
tty = current->signal->tty; /* Safe as we hold the siglock */
|
|
ac->ac_tty = tty ? old_encode_dev(tty_devnum(tty)) : 0;
|
|
ac->ac_utime = encode_comp_t(nsec_to_AHZ(pacct->ac_utime));
|
|
ac->ac_stime = encode_comp_t(nsec_to_AHZ(pacct->ac_stime));
|
|
ac->ac_flag = pacct->ac_flag;
|
|
ac->ac_mem = encode_comp_t(pacct->ac_mem);
|
|
ac->ac_minflt = encode_comp_t(pacct->ac_minflt);
|
|
ac->ac_majflt = encode_comp_t(pacct->ac_majflt);
|
|
ac->ac_exitcode = pacct->ac_exitcode;
|
|
spin_unlock_irq(¤t->sighand->siglock);
|
|
}
|
|
/*
|
|
* do_acct_process does all actual work. Caller holds the reference to file.
|
|
*/
|
|
static void do_acct_process(struct bsd_acct_struct *acct)
|
|
{
|
|
acct_t ac;
|
|
unsigned long flim;
|
|
const struct cred *orig_cred;
|
|
struct file *file = acct->file;
|
|
|
|
/*
|
|
* Accounting records are not subject to resource limits.
|
|
*/
|
|
flim = rlimit(RLIMIT_FSIZE);
|
|
current->signal->rlim[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;
|
|
/* Perform file operations on behalf of whoever enabled accounting */
|
|
orig_cred = override_creds(file->f_cred);
|
|
|
|
/*
|
|
* First check to see if there is enough free_space to continue
|
|
* the process accounting system.
|
|
*/
|
|
if (!check_free_space(acct))
|
|
goto out;
|
|
|
|
fill_ac(&ac);
|
|
/* we really need to bite the bullet and change layout */
|
|
ac.ac_uid = from_kuid_munged(file->f_cred->user_ns, orig_cred->uid);
|
|
ac.ac_gid = from_kgid_munged(file->f_cred->user_ns, orig_cred->gid);
|
|
#if ACCT_VERSION == 1 || ACCT_VERSION == 2
|
|
/* backward-compatible 16 bit fields */
|
|
ac.ac_uid16 = ac.ac_uid;
|
|
ac.ac_gid16 = ac.ac_gid;
|
|
#elif ACCT_VERSION == 3
|
|
{
|
|
struct pid_namespace *ns = acct->ns;
|
|
|
|
ac.ac_pid = task_tgid_nr_ns(current, ns);
|
|
rcu_read_lock();
|
|
ac.ac_ppid = task_tgid_nr_ns(rcu_dereference(current->real_parent),
|
|
ns);
|
|
rcu_read_unlock();
|
|
}
|
|
#endif
|
|
/*
|
|
* Get freeze protection. If the fs is frozen, just skip the write
|
|
* as we could deadlock the system otherwise.
|
|
*/
|
|
if (file_start_write_trylock(file)) {
|
|
/* it's been opened O_APPEND, so position is irrelevant */
|
|
loff_t pos = 0;
|
|
__kernel_write(file, &ac, sizeof(acct_t), &pos);
|
|
file_end_write(file);
|
|
}
|
|
out:
|
|
current->signal->rlim[RLIMIT_FSIZE].rlim_cur = flim;
|
|
revert_creds(orig_cred);
|
|
}
|
|
|
|
/**
|
|
* acct_collect - collect accounting information into pacct_struct
|
|
* @exitcode: task exit code
|
|
* @group_dead: not 0, if this thread is the last one in the process.
|
|
*/
|
|
void acct_collect(long exitcode, int group_dead)
|
|
{
|
|
struct pacct_struct *pacct = ¤t->signal->pacct;
|
|
u64 utime, stime;
|
|
unsigned long vsize = 0;
|
|
|
|
if (group_dead && current->mm) {
|
|
struct mm_struct *mm = current->mm;
|
|
VMA_ITERATOR(vmi, mm, 0);
|
|
struct vm_area_struct *vma;
|
|
|
|
mmap_read_lock(mm);
|
|
for_each_vma(vmi, vma)
|
|
vsize += vma->vm_end - vma->vm_start;
|
|
mmap_read_unlock(mm);
|
|
}
|
|
|
|
spin_lock_irq(¤t->sighand->siglock);
|
|
if (group_dead)
|
|
pacct->ac_mem = vsize / 1024;
|
|
if (thread_group_leader(current)) {
|
|
pacct->ac_exitcode = exitcode;
|
|
if (current->flags & PF_FORKNOEXEC)
|
|
pacct->ac_flag |= AFORK;
|
|
}
|
|
if (current->flags & PF_SUPERPRIV)
|
|
pacct->ac_flag |= ASU;
|
|
if (current->flags & PF_DUMPCORE)
|
|
pacct->ac_flag |= ACORE;
|
|
if (current->flags & PF_SIGNALED)
|
|
pacct->ac_flag |= AXSIG;
|
|
|
|
task_cputime(current, &utime, &stime);
|
|
pacct->ac_utime += utime;
|
|
pacct->ac_stime += stime;
|
|
pacct->ac_minflt += current->min_flt;
|
|
pacct->ac_majflt += current->maj_flt;
|
|
spin_unlock_irq(¤t->sighand->siglock);
|
|
}
|
|
|
|
static void slow_acct_process(struct pid_namespace *ns)
|
|
{
|
|
for ( ; ns; ns = ns->parent) {
|
|
struct bsd_acct_struct *acct = acct_get(ns);
|
|
if (acct) {
|
|
do_acct_process(acct);
|
|
mutex_unlock(&acct->lock);
|
|
acct_put(acct);
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* acct_process - handles process accounting for an exiting task
|
|
*/
|
|
void acct_process(void)
|
|
{
|
|
struct pid_namespace *ns;
|
|
|
|
/*
|
|
* This loop is safe lockless, since current is still
|
|
* alive and holds its namespace, which in turn holds
|
|
* its parent.
|
|
*/
|
|
for (ns = task_active_pid_ns(current); ns != NULL; ns = ns->parent) {
|
|
if (ns->bacct)
|
|
break;
|
|
}
|
|
if (unlikely(ns))
|
|
slow_acct_process(ns);
|
|
}
|