diff options
| -rw-r--r-- | fs/exec.c | 18 | ||||
| -rw-r--r-- | fs/internal.h | 8 | ||||
| -rw-r--r-- | fs/namei.c | 88 | ||||
| -rw-r--r-- | fs/open.c | 73 | ||||
| -rw-r--r-- | include/linux/fs.h | 2 |
5 files changed, 101 insertions, 88 deletions
diff --git a/fs/exec.c b/fs/exec.c index 52a447d9b6a..ba99e1abb1a 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -115,13 +115,16 @@ SYSCALL_DEFINE1(uselib, const char __user *, library) struct file *file; char *tmp = getname(library); int error = PTR_ERR(tmp); + static const struct open_flags uselib_flags = { + .open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC, + .acc_mode = MAY_READ | MAY_EXEC | MAY_OPEN, + .intent = LOOKUP_OPEN + }; if (IS_ERR(tmp)) goto out; - file = do_filp_open(AT_FDCWD, tmp, - O_LARGEFILE | O_RDONLY | __FMODE_EXEC, 0, - MAY_READ | MAY_EXEC | MAY_OPEN); + file = do_filp_open(AT_FDCWD, tmp, &uselib_flags, LOOKUP_FOLLOW); putname(tmp); error = PTR_ERR(file); if (IS_ERR(file)) @@ -721,10 +724,13 @@ struct file *open_exec(const char *name) { struct file *file; int err; + static const struct open_flags open_exec_flags = { + .open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC, + .acc_mode = MAY_EXEC | MAY_OPEN, + .intent = LOOKUP_OPEN + }; - file = do_filp_open(AT_FDCWD, name, - O_LARGEFILE | O_RDONLY | __FMODE_EXEC, 0, - MAY_EXEC | MAY_OPEN); + file = do_filp_open(AT_FDCWD, name, &open_exec_flags, LOOKUP_FOLLOW); if (IS_ERR(file)) goto out; diff --git a/fs/internal.h b/fs/internal.h index 9b976b57d7f..6fdbdf2c604 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -106,6 +106,14 @@ extern void put_super(struct super_block *sb); struct nameidata; extern struct file *nameidata_to_filp(struct nameidata *); extern void release_open_intent(struct nameidata *); +struct open_flags { + int open_flag; + int mode; + int acc_mode; + int intent; +}; +extern struct file *do_filp_open(int dfd, const char *pathname, + const struct open_flags *op, int lookup_flags); /* * inode.c diff --git a/fs/namei.c b/fs/namei.c index 5e4206f4537..9c7fa946abe 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2169,13 +2169,6 @@ exit: return ERR_PTR(error); } -struct open_flags { - int open_flag; - int mode; - int acc_mode; - int intent; -}; - /* * Handle O_CREAT case for do_filp_open */ @@ -2305,74 +2298,28 @@ exit: * open_to_namei_flags() for more details. */ struct file *do_filp_open(int dfd, const char *pathname, - int open_flag, int mode, int acc_mode) + const struct open_flags *op, int flags) { struct file *filp; struct nameidata nd; int error; struct path path; int count = 0; - int flag = open_to_namei_flags(open_flag); - int flags = 0; - struct open_flags op; - - if (!(open_flag & O_CREAT)) - mode = 0; - - /* Must never be set by userspace */ - open_flag &= ~FMODE_NONOTIFY; - - /* - * O_SYNC is implemented as __O_SYNC|O_DSYNC. As many places only - * check for O_DSYNC if the need any syncing at all we enforce it's - * always set instead of having to deal with possibly weird behaviour - * for malicious applications setting only __O_SYNC. - */ - if (open_flag & __O_SYNC) - open_flag |= O_DSYNC; - - op.open_flag = open_flag; - - if (!acc_mode) - acc_mode = MAY_OPEN | ACC_MODE(open_flag); - - /* O_TRUNC implies we need access checks for write permissions */ - if (open_flag & O_TRUNC) - acc_mode |= MAY_WRITE; - - /* Allow the LSM permission hook to distinguish append - access from general write access. */ - if (open_flag & O_APPEND) - acc_mode |= MAY_APPEND; - - op.acc_mode = acc_mode; - - op.intent = LOOKUP_OPEN; - if (open_flag & O_CREAT) { - op.intent |= LOOKUP_CREATE; - if (open_flag & O_EXCL) - op.intent |= LOOKUP_EXCL; - } - - if (open_flag & O_DIRECTORY) - flags |= LOOKUP_DIRECTORY; - if (!(open_flag & O_NOFOLLOW)) - flags |= LOOKUP_FOLLOW; filp = get_empty_filp(); if (!filp) return ERR_PTR(-ENFILE); - filp->f_flags = open_flag; + filp->f_flags = op->open_flag; nd.intent.open.file = filp; - nd.intent.open.flags = flag; - nd.intent.open.create_mode = mode; + nd.intent.open.flags = open_to_namei_flags(op->open_flag); + nd.intent.open.create_mode = op->mode; - if (open_flag & O_CREAT) + if (op->open_flag & O_CREAT) goto creat; /* !O_CREAT, simple open */ - error = do_path_lookup(dfd, pathname, flags | op.intent, &nd); + error = do_path_lookup(dfd, pathname, flags | op->intent, &nd); if (unlikely(error)) goto out_filp2; error = -ELOOP; @@ -2386,7 +2333,7 @@ struct file *do_filp_open(int dfd, const char *pathname, goto out_path2; } audit_inode(pathname, nd.path.dentry); - filp = finish_open(&nd, open_flag, acc_mode); + filp = finish_open(&nd, op->open_flag, op->acc_mode); out2: release_open_intent(&nd); return filp; @@ -2416,7 +2363,7 @@ reval: /* * We have the parent and last component. */ - filp = do_last(&nd, &path, &op, pathname); + filp = do_last(&nd, &path, op, pathname); while (unlikely(!filp)) { /* trailing symlink */ struct path link = path; struct inode *linki = link.dentry->d_inode; @@ -2443,7 +2390,7 @@ reval: if (unlikely(error)) filp = ERR_PTR(error); else - filp = do_last(&nd, &path, &op, pathname); + filp = do_last(&nd, &path, op, pathname); if (!IS_ERR(cookie) && linki->i_op->put_link) linki->i_op->put_link(link.dentry, &nd, cookie); path_put(&link); @@ -2466,23 +2413,6 @@ out_filp: } /** - * filp_open - open file and return file pointer - * - * @filename: path to open - * @flags: open flags as per the open(2) second argument - * @mode: mode for the new file if O_CREAT is set, else ignored - * - * This is the helper to open a file from kernelspace if you really - * have to. But in generally you should not do this, so please move - * along, nothing to see here.. - */ -struct file *filp_open(const char *filename, int flags, int mode) -{ - return do_filp_open(AT_FDCWD, filename, flags, mode, 0); -} -EXPORT_SYMBOL(filp_open); - -/** * lookup_create - lookup a dentry, creating it if it doesn't exist * @nd: nameidata info * @is_dir: directory flag diff --git a/fs/open.c b/fs/open.c index b47aab39c05..d05e18c60ba 100644 --- a/fs/open.c +++ b/fs/open.c @@ -890,15 +890,86 @@ void fd_install(unsigned int fd, struct file *file) EXPORT_SYMBOL(fd_install); +static inline int build_open_flags(int flags, int mode, struct open_flags *op) +{ + int lookup_flags = 0; + int acc_mode; + + if (!(flags & O_CREAT)) + mode = 0; + op->mode = mode; + + /* Must never be set by userspace */ + flags &= ~FMODE_NONOTIFY; + + /* + * O_SYNC is implemented as __O_SYNC|O_DSYNC. As many places only + * check for O_DSYNC if the need any syncing at all we enforce it's + * always set instead of having to deal with possibly weird behaviour + * for malicious applications setting only __O_SYNC. + */ + if (flags & __O_SYNC) + flags |= O_DSYNC; + + op->open_flag = flags; + + acc_mode = MAY_OPEN | ACC_MODE(flags); + + /* O_TRUNC implies we need access checks for write permissions */ + if (flags & O_TRUNC) + acc_mode |= MAY_WRITE; + + /* Allow the LSM permission hook to distinguish append + access from general write access. */ + if (flags & O_APPEND) + acc_mode |= MAY_APPEND; + + op->acc_mode = acc_mode; + + op->intent = LOOKUP_OPEN; + if (flags & O_CREAT) { + op->intent |= LOOKUP_CREATE; + if (flags & O_EXCL) + op->intent |= LOOKUP_EXCL; + } + + if (flags & O_DIRECTORY) + lookup_flags |= LOOKUP_DIRECTORY; + if (!(flags & O_NOFOLLOW)) + lookup_flags |= LOOKUP_FOLLOW; + return lookup_flags; +} + +/** + * filp_open - open file and return file pointer + * + * @filename: path to open + * @flags: open flags as per the open(2) second argument + * @mode: mode for the new file if O_CREAT is set, else ignored + * + * This is the helper to open a file from kernelspace if you really + * have to. But in generally you should not do this, so please move + * along, nothing to see here.. + */ +struct file *filp_open(const char *filename, int flags, int mode) +{ + struct open_flags op; + int lookup = build_open_flags(flags, mode, &op); + return do_filp_open(AT_FDCWD, filename, &op, lookup); +} +EXPORT_SYMBOL(filp_open); + long do_sys_open(int dfd, const char __user *filename, int flags, int mode) { + struct open_flags op; + int lookup = build_open_flags(flags, mode, &op); char *tmp = getname(filename); int fd = PTR_ERR(tmp); if (!IS_ERR(tmp)) { fd = get_unused_fd_flags(flags); if (fd >= 0) { - struct file *f = do_filp_open(dfd, tmp, flags, mode, 0); + struct file *f = do_filp_open(dfd, tmp, &op, lookup); if (IS_ERR(f)) { put_unused_fd(fd); fd = PTR_ERR(f); diff --git a/include/linux/fs.h b/include/linux/fs.h index e38b50a4b9d..9c75714f92c 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2205,8 +2205,6 @@ extern struct file *create_read_pipe(struct file *f, int flags); extern struct file *create_write_pipe(int flags); extern void free_write_pipe(struct file *); -extern struct file *do_filp_open(int dfd, const char *pathname, - int open_flag, int mode, int acc_mode); extern int may_open(struct path *, int, int); extern int kernel_read(struct file *, loff_t, char *, unsigned long); |