Merge with Linux 2.1.72, part 2.

The new signal code with exception of the code for the rt signals.
The definitions in <asm/siginfo.h> and <asm/ucontext.h> are currently
just stolen from the Alpha and will need to be overhauled.

1 files changed, 335 insertions, 0 deletions

diff --git a/kernel/acct.c b/kernel/acct.c
new file mode 100644
index 000000000..27f99ff92
--- /dev/null
+++ b/kernel/acct.c
@@ -0,0 +1,335 @@
+/*
+ *  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.
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+
+#ifdef CONFIG_BSD_PROCESS_ACCT
+#include <linux/fs.h>
+#include <linux/vfs.h>
+#include <linux/types.h>
+#include <linux/fcntl.h>
+#include <linux/stat.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/timer.h>
+#include <linux/tty.h>
+#include <linux/acct.h>
+#include <linux/major.h>
+#include <linux/smp.h>
+#include <linux/smp_lock.h>
+
+#include <asm/uaccess.h>
+
+/*
+ * These constants control the amount of freespace that suspend and
+ * resume the process accounting system, and the time delay between
+ * each check.
+ */
+
+#define RESUME		(4)       /* More than 4% free space will resume */
+#define SUSPEND		(2)       /* Less than 2% free space will suspend */
+#define ACCT_TIMEOUT	(30 * HZ) /* 30 second timeout between checks */
+
+/*
+ * External references and all of the globals.
+ */
+extern int close_fp(struct file *);
+
+void acct_timeout(unsigned long);
+
+static volatile int acct_active = 0;
+static volatile int acct_needcheck = 0;
+static struct file *acct_file = NULL;
+static struct timer_list acct_timer = { NULL, NULL, 0, 0, acct_timeout };
+
+/*
+ * Called whenever the timer says to check the free space.
+ */
+void acct_timeout(unsigned long unused)
+{
+	acct_needcheck = 1;
+}
+
+/*
+ * Check the amount of free space and suspend/resume accordingly.
+ */
+static void check_free_space(void)
+{
+	mm_segment_t fs;
+	struct statfs sbuf;
+
+	if (!acct_file || !acct_needcheck)
+		return;
+
+	if (!acct_file->f_dentry->d_inode->i_sb->s_op ||
+            !acct_file->f_dentry->d_inode->i_sb->s_op->statfs)
+		return;
+
+	fs = get_fs();
+	set_fs(KERNEL_DS);
+	acct_file->f_dentry->d_inode->i_sb->s_op->statfs(acct_file->f_dentry->d_inode->i_sb, &sbuf, sizeof(struct statfs));
+	set_fs(fs);
+
+	if (acct_active) {
+		if (sbuf.f_bavail <= SUSPEND * sbuf.f_blocks / 100) {
+			acct_active = 0;
+			printk(KERN_INFO "Process accounting paused\r\n");
+		}
+	} else {
+		if (sbuf.f_bavail >= RESUME * sbuf.f_blocks / 100) {
+			acct_active = 1;
+			printk(KERN_INFO "Process accounting resumed\r\n");
+		}
+	}
+	del_timer(&acct_timer);
+	acct_needcheck = 0;
+	acct_timer.expires = jiffies + ACCT_TIMEOUT;
+	add_timer(&acct_timer);
+}
+
+/*
+ *  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.
+ */
+asmlinkage int sys_acct(const char *name)
+{
+	struct dentry *dentry;
+	struct inode *inode;
+	char *tmp;
+	int error = -EPERM;
+
+	lock_kernel();
+	if (!suser())
+		goto out;
+
+	if (name == (char *)NULL) {
+		if (acct_active) {
+			acct_process(0); 
+		        del_timer(&acct_timer);
+			acct_active = 0;
+			acct_needcheck = 0;
+			close_fp(acct_file);
+		}
+		error = 0;
+		goto out;
+	} else {
+		if (!acct_active) {
+			tmp = getname(name);
+			error = PTR_ERR(tmp);
+			if (IS_ERR(tmp))
+				goto out;
+
+			dentry = open_namei(tmp, O_RDWR, 0600);
+			putname(tmp);
+
+			error = PTR_ERR(dentry);
+			if (IS_ERR(dentry))
+				goto out;
+
+			inode = dentry->d_inode;
+
+			if (!S_ISREG(inode->i_mode)) {
+				dput(dentry);
+				error = -EACCES;
+				goto out;
+			}
+
+			if (!inode->i_op || !inode->i_op->default_file_ops || 
+			    !inode->i_op->default_file_ops->write) {
+				dput(dentry);
+				error = -EIO;
+				goto out;
+			}
+
+			if ((acct_file = get_empty_filp()) != (struct file *)NULL) {
+				acct_file->f_mode = (O_WRONLY + 1) & O_ACCMODE;
+				acct_file->f_flags = O_WRONLY;
+				acct_file->f_dentry = dentry;
+				acct_file->f_pos = inode->i_size;
+				acct_file->f_reada = 0;
+				acct_file->f_op = inode->i_op->default_file_ops;
+				if ((error = get_write_access(acct_file->f_dentry->d_inode)) == 0) {
+					if (acct_file->f_op && acct_file->f_op->open)
+						error = acct_file->f_op->open(inode, acct_file);
+					if (error == 0) {
+						acct_needcheck = 0;
+						acct_active = 1;
+						acct_timer.expires = jiffies + ACCT_TIMEOUT;
+						add_timer(&acct_timer);
+						error = 0;
+						goto out;
+					}
+					put_write_access(acct_file->f_dentry->d_inode);
+				}
+				acct_file->f_count--;
+			} else
+				error = -EUSERS;
+			dput(dentry);
+		} else
+			error = -EBUSY;
+	}
+out:
+	unlock_kernel();
+	return error;
+}
+
+void acct_auto_close(kdev_t dev)
+{
+	if (acct_active && acct_file && acct_file->f_dentry->d_inode->i_dev == dev)
+		sys_acct((char *)NULL);
+}
+
+/*
+ *  encode an unsigned long 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(unsigned long 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++;
+	}
+
+	/*
+         * Clean it up and polish it off.
+         */
+	exp <<= MANTSIZE;		/* Shift the exponent into place */
+	exp += value;			/* and add on the mantissa. */
+	return exp;
+}
+
+/*
+ *  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().
+ */
+#define KSTK_EIP(stack) (((unsigned long *)(stack))[1019])
+#define KSTK_ESP(stack) (((unsigned long *)(stack))[1022])
+
+int acct_process(long exitcode)
+{
+	struct acct ac;
+	mm_segment_t fs;
+	unsigned long vsize;
+
+	/*
+	 * First check to see if there is enough free_space to continue the process
+	 * accounting system. Check_free_space toggle's the acct_active flag so we
+	 * need to check that after check_free_space.
+	 */
+	check_free_space();
+
+	if (!acct_active)
+		return 0;
+
+
+	/*
+	 * Fill the accounting struct with the needed info as recorded by the different
+	 * kernel functions.
+	 */
+	memset((caddr_t)&ac, 0, sizeof(struct acct));
+
+	strncpy(ac.ac_comm, current->comm, ACCT_COMM);
+	ac.ac_comm[ACCT_COMM - 1] = '\0';
+
+	ac.ac_btime = CT_TO_SECS(current->start_time) + (xtime.tv_sec - (jiffies / HZ));
+	ac.ac_etime = encode_comp_t(jiffies - current->start_time);
+	ac.ac_utime = encode_comp_t(current->times.tms_utime);
+	ac.ac_stime = encode_comp_t(current->times.tms_stime);
+	ac.ac_uid = current->uid;
+	ac.ac_gid = current->gid;
+	ac.ac_tty = (current->tty) ? kdev_t_to_nr(current->tty->device) : 0;
+
+	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 = current->mm->mmap;
+		while (vma) {
+			vsize += vma->vm_end - vma->vm_start;
+			vma = vma->vm_next;
+		}
+	}
+	vsize = vsize / 1024;
+	ac.ac_mem = encode_comp_t(vsize);
+	ac.ac_io = encode_comp_t(current->io_usage);
+	ac.ac_rw = encode_comp_t(ac.ac_io / 1024);
+	ac.ac_minflt = encode_comp_t(current->min_flt);
+	ac.ac_majflt = encode_comp_t(current->maj_flt);
+	ac.ac_swaps = encode_comp_t(current->nswap);
+	ac.ac_exitcode = exitcode;
+
+	/*
+         * Kernel segment override to datasegment and write it to the accounting file.
+         */
+	fs = get_fs();
+	set_fs(KERNEL_DS);
+	acct_file->f_op->write(acct_file, (char *)&ac,
+			       sizeof(struct acct), &acct_file->f_pos);
+	set_fs(fs);
+	return 0;
+}
+
+#else
+/*
+ * Dummy system call when BSD process accounting is not configured
+ * into the kernel.
+ */
+
+asmlinkage int sys_acct(const char * filename)
+{
+	return -ENOSYS;
+}
+#endif