Revision 619b0488038224391e64fa03854651ca0f5efe56 authored by Raistlin on 26 June 2008, 16:54:09 UTC, committed by Ingo Molnar on 01 July 2008, 06:23:24 UTC
Here it is another little Oops we found while configuring invalid values via cgroups: echo 0 > /dev/cgroups/0/cpu.rt_period_us or echo 4294967296 > /dev/cgroups/0/cpu.rt_period_us [ 205.509825] divide error: 0000 [#1] [ 205.510151] Modules linked in: [ 205.510151] [ 205.510151] Pid: 2339, comm: bash Not tainted (2.6.26-rc8 #33) [ 205.510151] EIP: 0060:[<c030c6ef>] EFLAGS: 00000293 CPU: 0 [ 205.510151] EIP is at div64_u64+0x5f/0x70 [ 205.510151] EAX: 0000389f EBX: 00000000 ECX: 00000000 EDX: 00000000 [ 205.510151] ESI: d9800000 EDI: 00000000 EBP: c6cede60 ESP: c6cede50 [ 205.510151] DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068 [ 205.510151] Process bash (pid: 2339, ti=c6cec000 task=c79be370 task.ti=c6cec000) [ 205.510151] Stack: d9800000 0000389f c05971a0 d9800000 c6cedeb4 c0214dbd 00000000 00000000 [ 205.510151] c6cede88 c0242bd8 c05377c0 c7a41b40 00000000 00000000 00000000 c05971a0 [ 205.510151] c780ed20 c7508494 c7a41b40 00000000 00000002 c6cedebc c05971a0 ffffffea [ 205.510151] Call Trace: [ 205.510151] [<c0214dbd>] ? __rt_schedulable+0x1cd/0x240 [ 205.510151] [<c0242bd8>] ? cgroup_file_open+0x18/0xe0 [ 205.510151] [<c0214fe4>] ? tg_set_bandwidth+0xa4/0xf0 [ 205.510151] [<c0215066>] ? sched_group_set_rt_period+0x36/0x50 [ 205.510151] [<c021508e>] ? cpu_rt_period_write_uint+0xe/0x10 [ 205.510151] [<c0242dc5>] ? cgroup_file_write+0x125/0x160 [ 205.510151] [<c0232c15>] ? hrtimer_interrupt+0x155/0x190 [ 205.510151] [<c02f047f>] ? security_file_permission+0xf/0x20 [ 205.510151] [<c0277ad8>] ? rw_verify_area+0x48/0xc0 [ 205.510151] [<c0283744>] ? dupfd+0x104/0x130 [ 205.510151] [<c027838c>] ? vfs_write+0x9c/0x160 [ 205.510151] [<c0242ca0>] ? cgroup_file_write+0x0/0x160 [ 205.510151] [<c027850d>] ? sys_write+0x3d/0x70 [ 205.510151] [<c0203019>] ? sysenter_past_esp+0x6a/0x91 [ 205.510151] ======================= [ 205.510151] Code: 0f 45 de 31 f6 0f ad d0 d3 ea f6 c1 20 0f 45 c2 0f 45 d6 89 45 f0 89 55 f4 8b 55 f4 31 c9 8b 45 f0 39 d3 89 c6 77 08 89 d0 31 d2 <f7> f3 89 c1 83 c4 08 89 f0 f7 f3 89 ca 5b 5e 5d c3 55 89 e5 56 [ 205.510151] EIP: [<c030c6ef>] div64_u64+0x5f/0x70 SS:ESP 0068:c6cede50 The attached patch solves the issue for me. I'm checking as soon as possible for the period not being zero since, if it is, going ahead is useless. This way we also save a mutex_lock() and a read_lock() wrt doing it inside tg_set_bandwidth() or __rt_schedulable(). Signed-off-by: Dario Faggioli <raistlin@linux.it> Signed-off-by: Michael Trimarchi <trimarchimichael@yahoo.it> Signed-off-by: Ingo Molnar <mingo@elte.hu>
1 parent 79c5379
stat.c
/*
* linux/fs/stat.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*/
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/file.h>
#include <linux/highuid.h>
#include <linux/fs.h>
#include <linux/namei.h>
#include <linux/security.h>
#include <linux/syscalls.h>
#include <linux/pagemap.h>
#include <asm/uaccess.h>
#include <asm/unistd.h>
void generic_fillattr(struct inode *inode, struct kstat *stat)
{
stat->dev = inode->i_sb->s_dev;
stat->ino = inode->i_ino;
stat->mode = inode->i_mode;
stat->nlink = inode->i_nlink;
stat->uid = inode->i_uid;
stat->gid = inode->i_gid;
stat->rdev = inode->i_rdev;
stat->atime = inode->i_atime;
stat->mtime = inode->i_mtime;
stat->ctime = inode->i_ctime;
stat->size = i_size_read(inode);
stat->blocks = inode->i_blocks;
stat->blksize = (1 << inode->i_blkbits);
}
EXPORT_SYMBOL(generic_fillattr);
int vfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
{
struct inode *inode = dentry->d_inode;
int retval;
retval = security_inode_getattr(mnt, dentry);
if (retval)
return retval;
if (inode->i_op->getattr)
return inode->i_op->getattr(mnt, dentry, stat);
generic_fillattr(inode, stat);
return 0;
}
EXPORT_SYMBOL(vfs_getattr);
int vfs_stat_fd(int dfd, char __user *name, struct kstat *stat)
{
struct nameidata nd;
int error;
error = __user_walk_fd(dfd, name, LOOKUP_FOLLOW, &nd);
if (!error) {
error = vfs_getattr(nd.path.mnt, nd.path.dentry, stat);
path_put(&nd.path);
}
return error;
}
int vfs_stat(char __user *name, struct kstat *stat)
{
return vfs_stat_fd(AT_FDCWD, name, stat);
}
EXPORT_SYMBOL(vfs_stat);
int vfs_lstat_fd(int dfd, char __user *name, struct kstat *stat)
{
struct nameidata nd;
int error;
error = __user_walk_fd(dfd, name, 0, &nd);
if (!error) {
error = vfs_getattr(nd.path.mnt, nd.path.dentry, stat);
path_put(&nd.path);
}
return error;
}
int vfs_lstat(char __user *name, struct kstat *stat)
{
return vfs_lstat_fd(AT_FDCWD, name, stat);
}
EXPORT_SYMBOL(vfs_lstat);
int vfs_fstat(unsigned int fd, struct kstat *stat)
{
struct file *f = fget(fd);
int error = -EBADF;
if (f) {
error = vfs_getattr(f->f_path.mnt, f->f_path.dentry, stat);
fput(f);
}
return error;
}
EXPORT_SYMBOL(vfs_fstat);
#ifdef __ARCH_WANT_OLD_STAT
/*
* For backward compatibility? Maybe this should be moved
* into arch/i386 instead?
*/
static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf)
{
static int warncount = 5;
struct __old_kernel_stat tmp;
if (warncount > 0) {
warncount--;
printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n",
current->comm);
} else if (warncount < 0) {
/* it's laughable, but... */
warncount = 0;
}
memset(&tmp, 0, sizeof(struct __old_kernel_stat));
tmp.st_dev = old_encode_dev(stat->dev);
tmp.st_ino = stat->ino;
if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
return -EOVERFLOW;
tmp.st_mode = stat->mode;
tmp.st_nlink = stat->nlink;
if (tmp.st_nlink != stat->nlink)
return -EOVERFLOW;
SET_UID(tmp.st_uid, stat->uid);
SET_GID(tmp.st_gid, stat->gid);
tmp.st_rdev = old_encode_dev(stat->rdev);
#if BITS_PER_LONG == 32
if (stat->size > MAX_NON_LFS)
return -EOVERFLOW;
#endif
tmp.st_size = stat->size;
tmp.st_atime = stat->atime.tv_sec;
tmp.st_mtime = stat->mtime.tv_sec;
tmp.st_ctime = stat->ctime.tv_sec;
return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
}
asmlinkage long sys_stat(char __user * filename, struct __old_kernel_stat __user * statbuf)
{
struct kstat stat;
int error = vfs_stat_fd(AT_FDCWD, filename, &stat);
if (!error)
error = cp_old_stat(&stat, statbuf);
return error;
}
asmlinkage long sys_lstat(char __user * filename, struct __old_kernel_stat __user * statbuf)
{
struct kstat stat;
int error = vfs_lstat_fd(AT_FDCWD, filename, &stat);
if (!error)
error = cp_old_stat(&stat, statbuf);
return error;
}
asmlinkage long sys_fstat(unsigned int fd, struct __old_kernel_stat __user * statbuf)
{
struct kstat stat;
int error = vfs_fstat(fd, &stat);
if (!error)
error = cp_old_stat(&stat, statbuf);
return error;
}
#endif /* __ARCH_WANT_OLD_STAT */
static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf)
{
struct stat tmp;
#if BITS_PER_LONG == 32
if (!old_valid_dev(stat->dev) || !old_valid_dev(stat->rdev))
return -EOVERFLOW;
#else
if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev))
return -EOVERFLOW;
#endif
memset(&tmp, 0, sizeof(tmp));
#if BITS_PER_LONG == 32
tmp.st_dev = old_encode_dev(stat->dev);
#else
tmp.st_dev = new_encode_dev(stat->dev);
#endif
tmp.st_ino = stat->ino;
if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
return -EOVERFLOW;
tmp.st_mode = stat->mode;
tmp.st_nlink = stat->nlink;
if (tmp.st_nlink != stat->nlink)
return -EOVERFLOW;
SET_UID(tmp.st_uid, stat->uid);
SET_GID(tmp.st_gid, stat->gid);
#if BITS_PER_LONG == 32
tmp.st_rdev = old_encode_dev(stat->rdev);
#else
tmp.st_rdev = new_encode_dev(stat->rdev);
#endif
#if BITS_PER_LONG == 32
if (stat->size > MAX_NON_LFS)
return -EOVERFLOW;
#endif
tmp.st_size = stat->size;
tmp.st_atime = stat->atime.tv_sec;
tmp.st_mtime = stat->mtime.tv_sec;
tmp.st_ctime = stat->ctime.tv_sec;
#ifdef STAT_HAVE_NSEC
tmp.st_atime_nsec = stat->atime.tv_nsec;
tmp.st_mtime_nsec = stat->mtime.tv_nsec;
tmp.st_ctime_nsec = stat->ctime.tv_nsec;
#endif
tmp.st_blocks = stat->blocks;
tmp.st_blksize = stat->blksize;
return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
}
asmlinkage long sys_newstat(char __user *filename, struct stat __user *statbuf)
{
struct kstat stat;
int error = vfs_stat_fd(AT_FDCWD, filename, &stat);
if (!error)
error = cp_new_stat(&stat, statbuf);
return error;
}
asmlinkage long sys_newlstat(char __user *filename, struct stat __user *statbuf)
{
struct kstat stat;
int error = vfs_lstat_fd(AT_FDCWD, filename, &stat);
if (!error)
error = cp_new_stat(&stat, statbuf);
return error;
}
#if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT)
asmlinkage long sys_newfstatat(int dfd, char __user *filename,
struct stat __user *statbuf, int flag)
{
struct kstat stat;
int error = -EINVAL;
if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0)
goto out;
if (flag & AT_SYMLINK_NOFOLLOW)
error = vfs_lstat_fd(dfd, filename, &stat);
else
error = vfs_stat_fd(dfd, filename, &stat);
if (!error)
error = cp_new_stat(&stat, statbuf);
out:
return error;
}
#endif
asmlinkage long sys_newfstat(unsigned int fd, struct stat __user *statbuf)
{
struct kstat stat;
int error = vfs_fstat(fd, &stat);
if (!error)
error = cp_new_stat(&stat, statbuf);
return error;
}
asmlinkage long sys_readlinkat(int dfd, const char __user *path,
char __user *buf, int bufsiz)
{
struct nameidata nd;
int error;
if (bufsiz <= 0)
return -EINVAL;
error = __user_walk_fd(dfd, path, 0, &nd);
if (!error) {
struct inode *inode = nd.path.dentry->d_inode;
error = -EINVAL;
if (inode->i_op && inode->i_op->readlink) {
error = security_inode_readlink(nd.path.dentry);
if (!error) {
touch_atime(nd.path.mnt, nd.path.dentry);
error = inode->i_op->readlink(nd.path.dentry,
buf, bufsiz);
}
}
path_put(&nd.path);
}
return error;
}
asmlinkage long sys_readlink(const char __user *path, char __user *buf,
int bufsiz)
{
return sys_readlinkat(AT_FDCWD, path, buf, bufsiz);
}
/* ---------- LFS-64 ----------- */
#ifdef __ARCH_WANT_STAT64
static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf)
{
struct stat64 tmp;
memset(&tmp, 0, sizeof(struct stat64));
#ifdef CONFIG_MIPS
/* mips has weird padding, so we don't get 64 bits there */
if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev))
return -EOVERFLOW;
tmp.st_dev = new_encode_dev(stat->dev);
tmp.st_rdev = new_encode_dev(stat->rdev);
#else
tmp.st_dev = huge_encode_dev(stat->dev);
tmp.st_rdev = huge_encode_dev(stat->rdev);
#endif
tmp.st_ino = stat->ino;
if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
return -EOVERFLOW;
#ifdef STAT64_HAS_BROKEN_ST_INO
tmp.__st_ino = stat->ino;
#endif
tmp.st_mode = stat->mode;
tmp.st_nlink = stat->nlink;
tmp.st_uid = stat->uid;
tmp.st_gid = stat->gid;
tmp.st_atime = stat->atime.tv_sec;
tmp.st_atime_nsec = stat->atime.tv_nsec;
tmp.st_mtime = stat->mtime.tv_sec;
tmp.st_mtime_nsec = stat->mtime.tv_nsec;
tmp.st_ctime = stat->ctime.tv_sec;
tmp.st_ctime_nsec = stat->ctime.tv_nsec;
tmp.st_size = stat->size;
tmp.st_blocks = stat->blocks;
tmp.st_blksize = stat->blksize;
return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
}
asmlinkage long sys_stat64(char __user * filename, struct stat64 __user * statbuf)
{
struct kstat stat;
int error = vfs_stat(filename, &stat);
if (!error)
error = cp_new_stat64(&stat, statbuf);
return error;
}
asmlinkage long sys_lstat64(char __user * filename, struct stat64 __user * statbuf)
{
struct kstat stat;
int error = vfs_lstat(filename, &stat);
if (!error)
error = cp_new_stat64(&stat, statbuf);
return error;
}
asmlinkage long sys_fstat64(unsigned long fd, struct stat64 __user * statbuf)
{
struct kstat stat;
int error = vfs_fstat(fd, &stat);
if (!error)
error = cp_new_stat64(&stat, statbuf);
return error;
}
asmlinkage long sys_fstatat64(int dfd, char __user *filename,
struct stat64 __user *statbuf, int flag)
{
struct kstat stat;
int error = -EINVAL;
if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0)
goto out;
if (flag & AT_SYMLINK_NOFOLLOW)
error = vfs_lstat_fd(dfd, filename, &stat);
else
error = vfs_stat_fd(dfd, filename, &stat);
if (!error)
error = cp_new_stat64(&stat, statbuf);
out:
return error;
}
#endif /* __ARCH_WANT_STAT64 */
void inode_add_bytes(struct inode *inode, loff_t bytes)
{
spin_lock(&inode->i_lock);
inode->i_blocks += bytes >> 9;
bytes &= 511;
inode->i_bytes += bytes;
if (inode->i_bytes >= 512) {
inode->i_blocks++;
inode->i_bytes -= 512;
}
spin_unlock(&inode->i_lock);
}
EXPORT_SYMBOL(inode_add_bytes);
void inode_sub_bytes(struct inode *inode, loff_t bytes)
{
spin_lock(&inode->i_lock);
inode->i_blocks -= bytes >> 9;
bytes &= 511;
if (inode->i_bytes < bytes) {
inode->i_blocks--;
inode->i_bytes += 512;
}
inode->i_bytes -= bytes;
spin_unlock(&inode->i_lock);
}
EXPORT_SYMBOL(inode_sub_bytes);
loff_t inode_get_bytes(struct inode *inode)
{
loff_t ret;
spin_lock(&inode->i_lock);
ret = (((loff_t)inode->i_blocks) << 9) + inode->i_bytes;
spin_unlock(&inode->i_lock);
return ret;
}
EXPORT_SYMBOL(inode_get_bytes);
void inode_set_bytes(struct inode *inode, loff_t bytes)
{
/* Caller is here responsible for sufficient locking
* (ie. inode->i_lock) */
inode->i_blocks = bytes >> 9;
inode->i_bytes = bytes & 511;
}
EXPORT_SYMBOL(inode_set_bytes);
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