X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Fnamei.c;h=f3c5b278895a0d3e0f23fe6fd474e2728a1c6cb6;hb=80fc015bdfe1f5b870c1e1ee02d78e709523fee7;hp=4c65a64601384470db0d58c2df63317c0da0f14c;hpb=3e93cd671813e204c258f1e6c797959920cf7772;p=safe%2Fjmp%2Flinux-2.6 diff --git a/fs/namei.c b/fs/namei.c index 4c65a64..f3c5b27 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -32,6 +32,7 @@ #include #include #include +#include #include #define ACC_MODE(x) ("\000\004\002\006"[(x)&O_ACCMODE]) @@ -551,6 +552,17 @@ static __always_inline int link_path_walk(const char *name, struct nameidata *nd return result; } +static __always_inline void set_root(struct nameidata *nd) +{ + if (!nd->root.mnt) { + struct fs_struct *fs = current->fs; + read_lock(&fs->lock); + nd->root = fs->root; + path_get(&nd->root); + read_unlock(&fs->lock); + } +} + static __always_inline int __vfs_follow_link(struct nameidata *nd, const char *link) { int res = 0; @@ -559,14 +571,10 @@ static __always_inline int __vfs_follow_link(struct nameidata *nd, const char *l goto fail; if (*link == '/') { - struct fs_struct *fs = current->fs; - + set_root(nd); path_put(&nd->path); - - read_lock(&fs->lock); - nd->path = fs->root; - path_get(&fs->root); - read_unlock(&fs->lock); + nd->path = nd->root; + path_get(&nd->root); } res = link_path_walk(link, nd); @@ -667,23 +675,23 @@ loop: return err; } -int follow_up(struct vfsmount **mnt, struct dentry **dentry) +int follow_up(struct path *path) { struct vfsmount *parent; struct dentry *mountpoint; spin_lock(&vfsmount_lock); - parent=(*mnt)->mnt_parent; - if (parent == *mnt) { + parent = path->mnt->mnt_parent; + if (parent == path->mnt) { spin_unlock(&vfsmount_lock); return 0; } mntget(parent); - mountpoint=dget((*mnt)->mnt_mountpoint); + mountpoint = dget(path->mnt->mnt_mountpoint); spin_unlock(&vfsmount_lock); - dput(*dentry); - *dentry = mountpoint; - mntput(*mnt); - *mnt = parent; + dput(path->dentry); + path->dentry = mountpoint; + mntput(path->mnt); + path->mnt = parent; return 1; } @@ -694,7 +702,7 @@ static int __follow_mount(struct path *path) { int res = 0; while (d_mountpoint(path->dentry)) { - struct vfsmount *mounted = lookup_mnt(path->mnt, path->dentry); + struct vfsmount *mounted = lookup_mnt(path); if (!mounted) break; dput(path->dentry); @@ -707,32 +715,32 @@ static int __follow_mount(struct path *path) return res; } -static void follow_mount(struct vfsmount **mnt, struct dentry **dentry) +static void follow_mount(struct path *path) { - while (d_mountpoint(*dentry)) { - struct vfsmount *mounted = lookup_mnt(*mnt, *dentry); + while (d_mountpoint(path->dentry)) { + struct vfsmount *mounted = lookup_mnt(path); if (!mounted) break; - dput(*dentry); - mntput(*mnt); - *mnt = mounted; - *dentry = dget(mounted->mnt_root); + dput(path->dentry); + mntput(path->mnt); + path->mnt = mounted; + path->dentry = dget(mounted->mnt_root); } } /* no need for dcache_lock, as serialization is taken care in * namespace.c */ -int follow_down(struct vfsmount **mnt, struct dentry **dentry) +int follow_down(struct path *path) { struct vfsmount *mounted; - mounted = lookup_mnt(*mnt, *dentry); + mounted = lookup_mnt(path); if (mounted) { - dput(*dentry); - mntput(*mnt); - *mnt = mounted; - *dentry = dget(mounted->mnt_root); + dput(path->dentry); + mntput(path->mnt); + path->mnt = mounted; + path->dentry = dget(mounted->mnt_root); return 1; } return 0; @@ -740,19 +748,16 @@ int follow_down(struct vfsmount **mnt, struct dentry **dentry) static __always_inline void follow_dotdot(struct nameidata *nd) { - struct fs_struct *fs = current->fs; + set_root(nd); while(1) { struct vfsmount *parent; struct dentry *old = nd->path.dentry; - read_lock(&fs->lock); - if (nd->path.dentry == fs->root.dentry && - nd->path.mnt == fs->root.mnt) { - read_unlock(&fs->lock); + if (nd->path.dentry == nd->root.dentry && + nd->path.mnt == nd->root.mnt) { break; } - read_unlock(&fs->lock); spin_lock(&dcache_lock); if (nd->path.dentry != nd->path.mnt->mnt_root) { nd->path.dentry = dget(nd->path.dentry->d_parent); @@ -774,7 +779,7 @@ static __always_inline void follow_dotdot(struct nameidata *nd) mntput(nd->path.mnt); nd->path.mnt = parent; } - follow_mount(&nd->path.mnt, &nd->path.dentry); + follow_mount(&nd->path); } /* @@ -852,7 +857,8 @@ static int __link_path_walk(const char *name, struct nameidata *nd) err = inode_permission(nd->path.dentry->d_inode, MAY_EXEC); if (!err) - err = ima_path_check(&nd->path, MAY_EXEC); + err = ima_path_check(&nd->path, MAY_EXEC, + IMA_COUNT_UPDATE); if (err) break; @@ -1015,25 +1021,23 @@ static int path_walk(const char *name, struct nameidata *nd) return link_path_walk(name, nd); } -/* Returns 0 and nd will be valid on success; Retuns error, otherwise. */ -static int do_path_lookup(int dfd, const char *name, - unsigned int flags, struct nameidata *nd) +static int path_init(int dfd, const char *name, unsigned int flags, struct nameidata *nd) { int retval = 0; int fput_needed; struct file *file; - struct fs_struct *fs = current->fs; nd->last_type = LAST_ROOT; /* if there are only slashes... */ nd->flags = flags; nd->depth = 0; + nd->root.mnt = NULL; if (*name=='/') { - read_lock(&fs->lock); - nd->path = fs->root; - path_get(&fs->root); - read_unlock(&fs->lock); + set_root(nd); + nd->path = nd->root; + path_get(&nd->root); } else if (dfd == AT_FDCWD) { + struct fs_struct *fs = current->fs; read_lock(&fs->lock); nd->path = fs->pwd; path_get(&fs->pwd); @@ -1061,17 +1065,29 @@ static int do_path_lookup(int dfd, const char *name, fput_light(file, fput_needed); } + return 0; - retval = path_walk(name, nd); +fput_fail: + fput_light(file, fput_needed); +out_fail: + return retval; +} + +/* Returns 0 and nd will be valid on success; Retuns error, otherwise. */ +static int do_path_lookup(int dfd, const char *name, + unsigned int flags, struct nameidata *nd) +{ + int retval = path_init(dfd, name, flags, nd); + if (!retval) + retval = path_walk(name, nd); if (unlikely(!retval && !audit_dummy_context() && nd->path.dentry && nd->path.dentry->d_inode)) audit_inode(name, nd->path.dentry); -out_fail: + if (nd->root.mnt) { + path_put(&nd->root); + nd->root.mnt = NULL; + } return retval; - -fput_fail: - fput_light(file, fput_needed); - goto out_fail; } int path_lookup(const char *name, unsigned int flags, @@ -1111,14 +1127,18 @@ int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt, nd->path.dentry = dentry; nd->path.mnt = mnt; path_get(&nd->path); + nd->root = nd->path; + path_get(&nd->root); retval = path_walk(name, nd); if (unlikely(!retval && !audit_dummy_context() && nd->path.dentry && nd->path.dentry->d_inode)) audit_inode(name, nd->path.dentry); - return retval; + path_put(&nd->root); + nd->root.mnt = NULL; + return retval; } /** @@ -1129,8 +1149,8 @@ int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt, * @nd: pointer to nameidata * @open_flags: open intent flags */ -int path_lookup_open(int dfd, const char *name, unsigned int lookup_flags, - struct nameidata *nd, int open_flags) +static int path_lookup_open(int dfd, const char *name, + unsigned int lookup_flags, struct nameidata *nd, int open_flags) { struct file *filp = get_empty_filp(); int err; @@ -1247,6 +1267,8 @@ struct dentry *lookup_one_len(const char *name, struct dentry *base, int len) int err; struct qstr this; + WARN_ON_ONCE(!mutex_is_locked(&base->d_inode->i_mutex)); + err = __lookup_one_len(name, &this, base, len); if (err) return ERR_PTR(err); @@ -1512,7 +1534,8 @@ int may_open(struct path *path, int acc_mode, int flag) return error; error = ima_path_check(path, - acc_mode & (MAY_READ | MAY_WRITE | MAY_EXEC)); + acc_mode & (MAY_READ | MAY_WRITE | MAY_EXEC), + IMA_COUNT_UPDATE); if (error) return error; /* @@ -1578,7 +1601,7 @@ static int __open_namei_create(struct nameidata *nd, struct path *path, struct dentry *dir = nd->path.dentry; if (!IS_POSIXACL(dir->d_inode)) - mode &= ~current->fs->umask; + mode &= ~current_umask(); error = security_path_mknod(&nd->path, path->dentry, mode, 0); if (error) goto out_unlock; @@ -1634,18 +1657,19 @@ static int open_will_write_to_fs(int flag, struct inode *inode) * open_to_namei_flags() for more details. */ struct file *do_filp_open(int dfd, const char *pathname, - int open_flag, int mode) + int open_flag, int mode, int acc_mode) { struct file *filp; struct nameidata nd; - int acc_mode, error; + int error; struct path path; struct dentry *dir; int count = 0; int will_write; int flag = open_to_namei_flags(open_flag); - acc_mode = MAY_OPEN | ACC_MODE(flag); + if (!acc_mode) + acc_mode = MAY_OPEN | ACC_MODE(flag); /* O_TRUNC implies we need access checks for write permissions */ if (flag & O_TRUNC) @@ -1670,9 +1694,17 @@ struct file *do_filp_open(int dfd, const char *pathname, /* * Create - we need to know the parent. */ - error = do_path_lookup(dfd, pathname, LOOKUP_PARENT, &nd); + error = path_init(dfd, pathname, LOOKUP_PARENT, &nd); if (error) return ERR_PTR(error); + error = path_walk(pathname, &nd); + if (error) { + if (nd.root.mnt) + path_put(&nd.root); + return ERR_PTR(error); + } + if (unlikely(!audit_dummy_context())) + audit_inode(pathname, nd.path.dentry); /* * We have the parent and last component. First of all, check @@ -1729,7 +1761,13 @@ do_last: goto exit; } filp = nameidata_to_filp(&nd, open_flag); + if (IS_ERR(filp)) + ima_counts_put(&nd.path, + acc_mode & (MAY_READ | MAY_WRITE | + MAY_EXEC)); mnt_drop_write(nd.path.mnt); + if (nd.root.mnt) + path_put(&nd.root); return filp; } @@ -1783,6 +1821,9 @@ ok: goto exit; } filp = nameidata_to_filp(&nd, open_flag); + if (IS_ERR(filp)) + ima_counts_put(&nd.path, + acc_mode & (MAY_READ | MAY_WRITE | MAY_EXEC)); /* * It is now safe to drop the mnt write * because the filp has had a write taken @@ -1790,6 +1831,8 @@ ok: */ if (will_write) mnt_drop_write(nd.path.mnt); + if (nd.root.mnt) + path_put(&nd.root); return filp; exit_mutex_unlock: @@ -1800,6 +1843,8 @@ exit: if (!IS_ERR(nd.intent.open.file)) release_open_intent(&nd); exit_parent: + if (nd.root.mnt) + path_put(&nd.root); path_put(&nd.path); return ERR_PTR(error); @@ -1828,6 +1873,8 @@ do_link: * with "intent.open". */ release_open_intent(&nd); + if (nd.root.mnt) + path_put(&nd.root); return ERR_PTR(error); } nd.flags &= ~LOOKUP_PARENT; @@ -1866,7 +1913,7 @@ do_link: */ struct file *filp_open(const char *filename, int flags, int mode) { - return do_filp_open(AT_FDCWD, filename, flags, mode); + return do_filp_open(AT_FDCWD, filename, flags, mode, 0); } EXPORT_SYMBOL(filp_open); @@ -1989,7 +2036,7 @@ SYSCALL_DEFINE4(mknodat, int, dfd, const char __user *, filename, int, mode, goto out_unlock; } if (!IS_POSIXACL(nd.path.dentry->d_inode)) - mode &= ~current->fs->umask; + mode &= ~current_umask(); error = may_mknod(mode); if (error) goto out_dput; @@ -2067,7 +2114,7 @@ SYSCALL_DEFINE3(mkdirat, int, dfd, const char __user *, pathname, int, mode) goto out_unlock; if (!IS_POSIXACL(nd.path.dentry->d_inode)) - mode &= ~current->fs->umask; + mode &= ~current_umask(); error = mnt_want_write(nd.path.mnt); if (error) goto out_dput;