Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
This commit is contained in:
Linus Torvalds
561
kernel/acct.c
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561
kernel/acct.c
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@@ -0,0 +1,561 @@
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/*
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* linux/kernel/acct.c
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*
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* BSD Process Accounting for Linux
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*
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* Author: Marco van Wieringen <mvw@planets.elm.net>
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*
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* Some code based on ideas and code from:
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* Thomas K. Dyas <tdyas@eden.rutgers.edu>
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*
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* This file implements BSD-style process accounting. Whenever any
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* process exits, an accounting record of type "struct acct" is
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* written to the file specified with the acct() system call. It is
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* up to user-level programs to do useful things with the accounting
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* log. The kernel just provides the raw accounting information.
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*
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* (C) Copyright 1995 - 1997 Marco van Wieringen - ELM Consultancy B.V.
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*
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* Plugged two leaks. 1) It didn't return acct_file into the free_filps if
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* the file happened to be read-only. 2) If the accounting was suspended
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* due to the lack of space it happily allowed to reopen it and completely
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* lost the old acct_file. 3/10/98, Al Viro.
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*
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* Now we silently close acct_file on attempt to reopen. Cleaned sys_acct().
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* XTerms and EMACS are manifestations of pure evil. 21/10/98, AV.
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*
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* Fixed a nasty interaction with with sys_umount(). If the accointing
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* was suspeneded we failed to stop it on umount(). Messy.
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* Another one: remount to readonly didn't stop accounting.
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* Question: what should we do if we have CAP_SYS_ADMIN but not
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* CAP_SYS_PACCT? Current code does the following: umount returns -EBUSY
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* unless we are messing with the root. In that case we are getting a
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* real mess with do_remount_sb(). 9/11/98, AV.
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*
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* Fixed a bunch of races (and pair of leaks). Probably not the best way,
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* but this one obviously doesn't introduce deadlocks. Later. BTW, found
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* one race (and leak) in BSD implementation.
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* OK, that's better. ANOTHER race and leak in BSD variant. There always
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* is one more bug... 10/11/98, AV.
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*
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* Oh, fsck... Oopsable SMP race in do_process_acct() - we must hold
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* ->mmap_sem to walk the vma list of current->mm. Nasty, since it leaks
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* a struct file opened for write. Fixed. 2/6/2000, AV.
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*/
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#include <linux/config.h>
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#include <linux/mm.h>
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#include <linux/slab.h>
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#include <linux/acct.h>
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#include <linux/file.h>
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#include <linux/tty.h>
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#include <linux/security.h>
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#include <linux/vfs.h>
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#include <linux/jiffies.h>
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#include <linux/times.h>
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#include <linux/syscalls.h>
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#include <asm/uaccess.h>
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#include <asm/div64.h>
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#include <linux/blkdev.h> /* sector_div */
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/*
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* These constants control the amount of freespace that suspend and
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* resume the process accounting system, and the time delay between
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* each check.
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* Turned into sysctl-controllable parameters. AV, 12/11/98
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*/
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int acct_parm[3] = {4, 2, 30};
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#define RESUME (acct_parm[0]) /* >foo% free space - resume */
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#define SUSPEND (acct_parm[1]) /* <foo% free space - suspend */
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#define ACCT_TIMEOUT (acct_parm[2]) /* foo second timeout between checks */
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/*
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* External references and all of the globals.
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*/
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static void do_acct_process(long, struct file *);
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/*
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* This structure is used so that all the data protected by lock
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* can be placed in the same cache line as the lock. This primes
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* the cache line to have the data after getting the lock.
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*/
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struct acct_glbs {
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spinlock_t lock;
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volatile int active;
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volatile int needcheck;
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struct file *file;
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struct timer_list timer;
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};
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static struct acct_glbs acct_globals __cacheline_aligned = {SPIN_LOCK_UNLOCKED};
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/*
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* Called whenever the timer says to check the free space.
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*/
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static void acct_timeout(unsigned long unused)
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{
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acct_globals.needcheck = 1;
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}
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/*
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* Check the amount of free space and suspend/resume accordingly.
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*/
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static int check_free_space(struct file *file)
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{
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struct kstatfs sbuf;
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int res;
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int act;
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sector_t resume;
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sector_t suspend;
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spin_lock(&acct_globals.lock);
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res = acct_globals.active;
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if (!file || !acct_globals.needcheck)
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goto out;
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spin_unlock(&acct_globals.lock);
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/* May block */
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if (vfs_statfs(file->f_dentry->d_inode->i_sb, &sbuf))
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return res;
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suspend = sbuf.f_blocks * SUSPEND;
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resume = sbuf.f_blocks * RESUME;
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sector_div(suspend, 100);
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sector_div(resume, 100);
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if (sbuf.f_bavail <= suspend)
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act = -1;
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else if (sbuf.f_bavail >= resume)
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act = 1;
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else
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act = 0;
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/*
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* If some joker switched acct_globals.file under us we'ld better be
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* silent and _not_ touch anything.
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*/
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spin_lock(&acct_globals.lock);
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if (file != acct_globals.file) {
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if (act)
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res = act>0;
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goto out;
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}
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if (acct_globals.active) {
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if (act < 0) {
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acct_globals.active = 0;
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printk(KERN_INFO "Process accounting paused\n");
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}
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} else {
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if (act > 0) {
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acct_globals.active = 1;
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printk(KERN_INFO "Process accounting resumed\n");
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}
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}
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del_timer(&acct_globals.timer);
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acct_globals.needcheck = 0;
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acct_globals.timer.expires = jiffies + ACCT_TIMEOUT*HZ;
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add_timer(&acct_globals.timer);
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res = acct_globals.active;
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out:
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spin_unlock(&acct_globals.lock);
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return res;
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}
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/*
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* Close the old accouting file (if currently open) and then replace
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* it with file (if non-NULL).
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*
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* NOTE: acct_globals.lock MUST be held on entry and exit.
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*/
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static void acct_file_reopen(struct file *file)
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{
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struct file *old_acct = NULL;
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if (acct_globals.file) {
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old_acct = acct_globals.file;
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del_timer(&acct_globals.timer);
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acct_globals.active = 0;
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acct_globals.needcheck = 0;
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acct_globals.file = NULL;
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}
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if (file) {
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acct_globals.file = file;
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acct_globals.needcheck = 0;
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acct_globals.active = 1;
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/* It's been deleted if it was used before so this is safe */
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init_timer(&acct_globals.timer);
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acct_globals.timer.function = acct_timeout;
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acct_globals.timer.expires = jiffies + ACCT_TIMEOUT*HZ;
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add_timer(&acct_globals.timer);
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}
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if (old_acct) {
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spin_unlock(&acct_globals.lock);
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do_acct_process(0, old_acct);
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filp_close(old_acct, NULL);
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spin_lock(&acct_globals.lock);
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}
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}
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/*
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* sys_acct() is the only system call needed to implement process
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* accounting. It takes the name of the file where accounting records
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* should be written. If the filename is NULL, accounting will be
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* shutdown.
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*/
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asmlinkage long sys_acct(const char __user *name)
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{
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struct file *file = NULL;
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char *tmp;
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int error;
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if (!capable(CAP_SYS_PACCT))
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return -EPERM;
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if (name) {
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tmp = getname(name);
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if (IS_ERR(tmp)) {
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return (PTR_ERR(tmp));
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}
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/* Difference from BSD - they don't do O_APPEND */
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file = filp_open(tmp, O_WRONLY|O_APPEND, 0);
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putname(tmp);
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if (IS_ERR(file)) {
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return (PTR_ERR(file));
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}
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if (!S_ISREG(file->f_dentry->d_inode->i_mode)) {
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filp_close(file, NULL);
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return (-EACCES);
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}
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if (!file->f_op->write) {
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filp_close(file, NULL);
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return (-EIO);
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}
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}
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error = security_acct(file);
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if (error) {
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if (file)
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filp_close(file, NULL);
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return error;
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}
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spin_lock(&acct_globals.lock);
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acct_file_reopen(file);
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spin_unlock(&acct_globals.lock);
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return (0);
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}
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/*
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* If the accouting is turned on for a file in the filesystem pointed
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* to by sb, turn accouting off.
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*/
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void acct_auto_close(struct super_block *sb)
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{
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spin_lock(&acct_globals.lock);
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if (acct_globals.file &&
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acct_globals.file->f_dentry->d_inode->i_sb == sb) {
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acct_file_reopen((struct file *)NULL);
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}
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spin_unlock(&acct_globals.lock);
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}
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/*
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* encode an unsigned long into a comp_t
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*
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* This routine has been adopted from the encode_comp_t() function in
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* the kern_acct.c file of the FreeBSD operating system. The encoding
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* is a 13-bit fraction with a 3-bit (base 8) exponent.
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*/
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#define MANTSIZE 13 /* 13 bit mantissa. */
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#define EXPSIZE 3 /* Base 8 (3 bit) exponent. */
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#define MAXFRACT ((1 << MANTSIZE) - 1) /* Maximum fractional value. */
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static comp_t encode_comp_t(unsigned long value)
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{
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int exp, rnd;
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exp = rnd = 0;
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while (value > MAXFRACT) {
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rnd = value & (1 << (EXPSIZE - 1)); /* Round up? */
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value >>= EXPSIZE; /* Base 8 exponent == 3 bit shift. */
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exp++;
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}
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/*
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* If we need to round up, do it (and handle overflow correctly).
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*/
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if (rnd && (++value > MAXFRACT)) {
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value >>= EXPSIZE;
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exp++;
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}
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/*
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* Clean it up and polish it off.
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*/
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exp <<= MANTSIZE; /* Shift the exponent into place */
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exp += value; /* and add on the mantissa. */
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return exp;
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}
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#if ACCT_VERSION==1 || ACCT_VERSION==2
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/*
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* encode an u64 into a comp2_t (24 bits)
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*
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* Format: 5 bit base 2 exponent, 20 bits mantissa.
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* The leading bit of the mantissa is not stored, but implied for
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* non-zero exponents.
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* Largest encodable value is 50 bits.
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*/
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#define MANTSIZE2 20 /* 20 bit mantissa. */
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#define EXPSIZE2 5 /* 5 bit base 2 exponent. */
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#define MAXFRACT2 ((1ul << MANTSIZE2) - 1) /* Maximum fractional value. */
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#define MAXEXP2 ((1 <<EXPSIZE2) - 1) /* Maximum exponent. */
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static comp2_t encode_comp2_t(u64 value)
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{
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int exp, rnd;
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exp = (value > (MAXFRACT2>>1));
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rnd = 0;
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while (value > MAXFRACT2) {
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rnd = value & 1;
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value >>= 1;
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exp++;
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}
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/*
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* If we need to round up, do it (and handle overflow correctly).
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*/
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if (rnd && (++value > MAXFRACT2)) {
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value >>= 1;
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exp++;
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}
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if (exp > MAXEXP2) {
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/* Overflow. Return largest representable number instead. */
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return (1ul << (MANTSIZE2+EXPSIZE2-1)) - 1;
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} else {
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return (value & (MAXFRACT2>>1)) | (exp << (MANTSIZE2-1));
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}
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}
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#endif
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#if ACCT_VERSION==3
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/*
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* encode an u64 into a 32 bit IEEE float
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*/
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static u32 encode_float(u64 value)
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{
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unsigned exp = 190;
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unsigned u;
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if (value==0) return 0;
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while ((s64)value > 0){
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value <<= 1;
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exp--;
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}
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u = (u32)(value >> 40) & 0x7fffffu;
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return u | (exp << 23);
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}
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#endif
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/*
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* Write an accounting entry for an exiting process
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*
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* The acct_process() call is the workhorse of the process
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* accounting system. The struct acct is built here and then written
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* into the accounting file. This function should only be called from
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* do_exit().
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*/
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/*
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* do_acct_process does all actual work. Caller holds the reference to file.
|
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*/
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static void do_acct_process(long exitcode, struct file *file)
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{
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acct_t ac;
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mm_segment_t fs;
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unsigned long vsize;
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unsigned long flim;
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u64 elapsed;
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u64 run_time;
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struct timespec uptime;
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/*
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* First check to see if there is enough free_space to continue
|
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* the process accounting system.
|
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*/
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if (!check_free_space(file))
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return;
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/*
|
||||
* Fill the accounting struct with the needed info as recorded
|
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* by the different kernel functions.
|
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*/
|
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memset((caddr_t)&ac, 0, sizeof(acct_t));
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ac.ac_version = ACCT_VERSION | ACCT_BYTEORDER;
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strlcpy(ac.ac_comm, current->comm, sizeof(ac.ac_comm));
|
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|
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/* calculate run_time in nsec*/
|
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do_posix_clock_monotonic_gettime(&uptime);
|
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run_time = (u64)uptime.tv_sec*NSEC_PER_SEC + uptime.tv_nsec;
|
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run_time -= (u64)current->start_time.tv_sec*NSEC_PER_SEC
|
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+ current->start_time.tv_nsec;
|
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/* convert nsec -> AHZ */
|
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elapsed = nsec_to_AHZ(run_time);
|
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#if ACCT_VERSION==3
|
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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);
|
||||
ac.ac_btime = xtime.tv_sec - elapsed;
|
||||
ac.ac_utime = encode_comp_t(jiffies_to_AHZ(
|
||||
current->signal->utime +
|
||||
current->group_leader->utime));
|
||||
ac.ac_stime = encode_comp_t(jiffies_to_AHZ(
|
||||
current->signal->stime +
|
||||
current->group_leader->stime));
|
||||
/* we really need to bite the bullet and change layout */
|
||||
ac.ac_uid = current->uid;
|
||||
ac.ac_gid = current->gid;
|
||||
#if ACCT_VERSION==2
|
||||
ac.ac_ahz = AHZ;
|
||||
#endif
|
||||
#if ACCT_VERSION==1 || ACCT_VERSION==2
|
||||
/* backward-compatible 16 bit fields */
|
||||
ac.ac_uid16 = current->uid;
|
||||
ac.ac_gid16 = current->gid;
|
||||
#endif
|
||||
#if ACCT_VERSION==3
|
||||
ac.ac_pid = current->tgid;
|
||||
ac.ac_ppid = current->parent->tgid;
|
||||
#endif
|
||||
|
||||
read_lock(&tasklist_lock); /* pin current->signal */
|
||||
ac.ac_tty = current->signal->tty ?
|
||||
old_encode_dev(tty_devnum(current->signal->tty)) : 0;
|
||||
read_unlock(&tasklist_lock);
|
||||
|
||||
ac.ac_flag = 0;
|
||||
if (current->flags & PF_FORKNOEXEC)
|
||||
ac.ac_flag |= AFORK;
|
||||
if (current->flags & PF_SUPERPRIV)
|
||||
ac.ac_flag |= ASU;
|
||||
if (current->flags & PF_DUMPCORE)
|
||||
ac.ac_flag |= ACORE;
|
||||
if (current->flags & PF_SIGNALED)
|
||||
ac.ac_flag |= AXSIG;
|
||||
|
||||
vsize = 0;
|
||||
if (current->mm) {
|
||||
struct vm_area_struct *vma;
|
||||
down_read(¤t->mm->mmap_sem);
|
||||
vma = current->mm->mmap;
|
||||
while (vma) {
|
||||
vsize += vma->vm_end - vma->vm_start;
|
||||
vma = vma->vm_next;
|
||||
}
|
||||
up_read(¤t->mm->mmap_sem);
|
||||
}
|
||||
vsize = vsize / 1024;
|
||||
ac.ac_mem = encode_comp_t(vsize);
|
||||
ac.ac_io = encode_comp_t(0 /* current->io_usage */); /* %% */
|
||||
ac.ac_rw = encode_comp_t(ac.ac_io / 1024);
|
||||
ac.ac_minflt = encode_comp_t(current->signal->min_flt +
|
||||
current->group_leader->min_flt);
|
||||
ac.ac_majflt = encode_comp_t(current->signal->maj_flt +
|
||||
current->group_leader->maj_flt);
|
||||
ac.ac_swaps = encode_comp_t(0);
|
||||
ac.ac_exitcode = exitcode;
|
||||
|
||||
/*
|
||||
* Kernel segment override to datasegment and write it
|
||||
* to the accounting file.
|
||||
*/
|
||||
fs = get_fs();
|
||||
set_fs(KERNEL_DS);
|
||||
/*
|
||||
* Accounting records are not subject to resource limits.
|
||||
*/
|
||||
flim = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
|
||||
current->signal->rlim[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;
|
||||
file->f_op->write(file, (char *)&ac,
|
||||
sizeof(acct_t), &file->f_pos);
|
||||
current->signal->rlim[RLIMIT_FSIZE].rlim_cur = flim;
|
||||
set_fs(fs);
|
||||
}
|
||||
|
||||
/*
|
||||
* acct_process - now just a wrapper around do_acct_process
|
||||
*/
|
||||
void acct_process(long exitcode)
|
||||
{
|
||||
struct file *file = NULL;
|
||||
|
||||
/*
|
||||
* accelerate the common fastpath:
|
||||
*/
|
||||
if (!acct_globals.file)
|
||||
return;
|
||||
|
||||
spin_lock(&acct_globals.lock);
|
||||
file = acct_globals.file;
|
||||
if (unlikely(!file)) {
|
||||
spin_unlock(&acct_globals.lock);
|
||||
return;
|
||||
}
|
||||
get_file(file);
|
||||
spin_unlock(&acct_globals.lock);
|
||||
|
||||
do_acct_process(exitcode, file);
|
||||
fput(file);
|
||||
}
|
||||
|
||||
|
||||
/*
|
||||
* acct_update_integrals
|
||||
* - update mm integral fields in task_struct
|
||||
*/
|
||||
void acct_update_integrals(struct task_struct *tsk)
|
||||
{
|
||||
if (likely(tsk->mm)) {
|
||||
long delta = tsk->stime - tsk->acct_stimexpd;
|
||||
|
||||
if (delta == 0)
|
||||
return;
|
||||
tsk->acct_stimexpd = tsk->stime;
|
||||
tsk->acct_rss_mem1 += delta * get_mm_counter(tsk->mm, rss);
|
||||
tsk->acct_vm_mem1 += delta * tsk->mm->total_vm;
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* acct_clear_integrals
|
||||
* - clear the mm integral fields in task_struct
|
||||
*/
|
||||
void acct_clear_integrals(struct task_struct *tsk)
|
||||
{
|
||||
if (tsk) {
|
||||
tsk->acct_stimexpd = 0;
|
||||
tsk->acct_rss_mem1 = 0;
|
||||
tsk->acct_vm_mem1 = 0;
|
||||
}
|
||||
}
|
||||
Reference in New Issue
Block a user