switch do_filp_open() to struct open_flags
take calculation of open_flags by open(2) arguments into new helper in fs/open.c, move filp_open() over there, have it and do_sys_open() use that helper, switch exec.c callers of do_filp_open() to explicit (and constant) struct open_flags. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro
Родитель
c3e380b0b3
Коммит
47c805dc2d
18
fs/exec.c
18
fs/exec.c
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@ -115,13 +115,16 @@ SYSCALL_DEFINE1(uselib, const char __user *, library)
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struct file *file;
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char *tmp = getname(library);
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int error = PTR_ERR(tmp);
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static const struct open_flags uselib_flags = {
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.open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC,
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.acc_mode = MAY_READ | MAY_EXEC | MAY_OPEN,
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.intent = LOOKUP_OPEN
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};
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if (IS_ERR(tmp))
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goto out;
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file = do_filp_open(AT_FDCWD, tmp,
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O_LARGEFILE | O_RDONLY | __FMODE_EXEC, 0,
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MAY_READ | MAY_EXEC | MAY_OPEN);
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file = do_filp_open(AT_FDCWD, tmp, &uselib_flags, LOOKUP_FOLLOW);
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putname(tmp);
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error = PTR_ERR(file);
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if (IS_ERR(file))
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@ -721,10 +724,13 @@ struct file *open_exec(const char *name)
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{
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struct file *file;
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int err;
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static const struct open_flags open_exec_flags = {
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.open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC,
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.acc_mode = MAY_EXEC | MAY_OPEN,
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.intent = LOOKUP_OPEN
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};
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file = do_filp_open(AT_FDCWD, name,
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O_LARGEFILE | O_RDONLY | __FMODE_EXEC, 0,
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MAY_EXEC | MAY_OPEN);
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file = do_filp_open(AT_FDCWD, name, &open_exec_flags, LOOKUP_FOLLOW);
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if (IS_ERR(file))
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goto out;
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@ -106,6 +106,14 @@ extern void put_super(struct super_block *sb);
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struct nameidata;
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extern struct file *nameidata_to_filp(struct nameidata *);
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extern void release_open_intent(struct nameidata *);
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struct open_flags {
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int open_flag;
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int mode;
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int acc_mode;
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int intent;
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};
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extern struct file *do_filp_open(int dfd, const char *pathname,
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const struct open_flags *op, int lookup_flags);
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/*
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* inode.c
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88
fs/namei.c
88
fs/namei.c
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@ -2169,13 +2169,6 @@ exit:
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return ERR_PTR(error);
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}
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struct open_flags {
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int open_flag;
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int mode;
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int acc_mode;
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int intent;
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};
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/*
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* Handle O_CREAT case for do_filp_open
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*/
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@ -2305,74 +2298,28 @@ exit:
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* open_to_namei_flags() for more details.
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*/
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struct file *do_filp_open(int dfd, const char *pathname,
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int open_flag, int mode, int acc_mode)
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const struct open_flags *op, int flags)
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{
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struct file *filp;
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struct nameidata nd;
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int error;
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struct path path;
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int count = 0;
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int flag = open_to_namei_flags(open_flag);
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int flags = 0;
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struct open_flags op;
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if (!(open_flag & O_CREAT))
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mode = 0;
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/* Must never be set by userspace */
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open_flag &= ~FMODE_NONOTIFY;
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/*
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* O_SYNC is implemented as __O_SYNC|O_DSYNC. As many places only
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* check for O_DSYNC if the need any syncing at all we enforce it's
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* always set instead of having to deal with possibly weird behaviour
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* for malicious applications setting only __O_SYNC.
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*/
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if (open_flag & __O_SYNC)
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open_flag |= O_DSYNC;
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op.open_flag = open_flag;
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if (!acc_mode)
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acc_mode = MAY_OPEN | ACC_MODE(open_flag);
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/* O_TRUNC implies we need access checks for write permissions */
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if (open_flag & O_TRUNC)
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acc_mode |= MAY_WRITE;
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/* Allow the LSM permission hook to distinguish append
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access from general write access. */
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if (open_flag & O_APPEND)
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acc_mode |= MAY_APPEND;
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op.acc_mode = acc_mode;
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op.intent = LOOKUP_OPEN;
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if (open_flag & O_CREAT) {
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op.intent |= LOOKUP_CREATE;
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if (open_flag & O_EXCL)
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op.intent |= LOOKUP_EXCL;
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}
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if (open_flag & O_DIRECTORY)
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flags |= LOOKUP_DIRECTORY;
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if (!(open_flag & O_NOFOLLOW))
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flags |= LOOKUP_FOLLOW;
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filp = get_empty_filp();
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if (!filp)
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return ERR_PTR(-ENFILE);
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filp->f_flags = open_flag;
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filp->f_flags = op->open_flag;
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nd.intent.open.file = filp;
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nd.intent.open.flags = flag;
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nd.intent.open.create_mode = mode;
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nd.intent.open.flags = open_to_namei_flags(op->open_flag);
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nd.intent.open.create_mode = op->mode;
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if (open_flag & O_CREAT)
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if (op->open_flag & O_CREAT)
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goto creat;
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/* !O_CREAT, simple open */
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error = do_path_lookup(dfd, pathname, flags | op.intent, &nd);
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error = do_path_lookup(dfd, pathname, flags | op->intent, &nd);
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if (unlikely(error))
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goto out_filp2;
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error = -ELOOP;
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@ -2386,7 +2333,7 @@ struct file *do_filp_open(int dfd, const char *pathname,
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goto out_path2;
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}
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audit_inode(pathname, nd.path.dentry);
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filp = finish_open(&nd, open_flag, acc_mode);
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filp = finish_open(&nd, op->open_flag, op->acc_mode);
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out2:
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release_open_intent(&nd);
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return filp;
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@ -2416,7 +2363,7 @@ reval:
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/*
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* We have the parent and last component.
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*/
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filp = do_last(&nd, &path, &op, pathname);
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filp = do_last(&nd, &path, op, pathname);
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while (unlikely(!filp)) { /* trailing symlink */
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struct path link = path;
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struct inode *linki = link.dentry->d_inode;
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@ -2443,7 +2390,7 @@ reval:
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if (unlikely(error))
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filp = ERR_PTR(error);
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else
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filp = do_last(&nd, &path, &op, pathname);
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filp = do_last(&nd, &path, op, pathname);
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if (!IS_ERR(cookie) && linki->i_op->put_link)
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linki->i_op->put_link(link.dentry, &nd, cookie);
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path_put(&link);
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@ -2465,23 +2412,6 @@ out_filp:
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goto out;
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}
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/**
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* filp_open - open file and return file pointer
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*
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* @filename: path to open
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* @flags: open flags as per the open(2) second argument
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* @mode: mode for the new file if O_CREAT is set, else ignored
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*
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* This is the helper to open a file from kernelspace if you really
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* have to. But in generally you should not do this, so please move
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* along, nothing to see here..
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*/
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struct file *filp_open(const char *filename, int flags, int mode)
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{
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return do_filp_open(AT_FDCWD, filename, flags, mode, 0);
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}
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EXPORT_SYMBOL(filp_open);
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/**
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* lookup_create - lookup a dentry, creating it if it doesn't exist
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* @nd: nameidata info
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73
fs/open.c
73
fs/open.c
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@ -890,15 +890,86 @@ void fd_install(unsigned int fd, struct file *file)
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EXPORT_SYMBOL(fd_install);
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static inline int build_open_flags(int flags, int mode, struct open_flags *op)
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{
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int lookup_flags = 0;
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int acc_mode;
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if (!(flags & O_CREAT))
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mode = 0;
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op->mode = mode;
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/* Must never be set by userspace */
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flags &= ~FMODE_NONOTIFY;
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/*
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* O_SYNC is implemented as __O_SYNC|O_DSYNC. As many places only
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* check for O_DSYNC if the need any syncing at all we enforce it's
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* always set instead of having to deal with possibly weird behaviour
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* for malicious applications setting only __O_SYNC.
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*/
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if (flags & __O_SYNC)
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flags |= O_DSYNC;
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op->open_flag = flags;
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acc_mode = MAY_OPEN | ACC_MODE(flags);
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/* O_TRUNC implies we need access checks for write permissions */
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if (flags & O_TRUNC)
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acc_mode |= MAY_WRITE;
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/* Allow the LSM permission hook to distinguish append
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access from general write access. */
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if (flags & O_APPEND)
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acc_mode |= MAY_APPEND;
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op->acc_mode = acc_mode;
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op->intent = LOOKUP_OPEN;
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if (flags & O_CREAT) {
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op->intent |= LOOKUP_CREATE;
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if (flags & O_EXCL)
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op->intent |= LOOKUP_EXCL;
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}
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if (flags & O_DIRECTORY)
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lookup_flags |= LOOKUP_DIRECTORY;
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if (!(flags & O_NOFOLLOW))
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lookup_flags |= LOOKUP_FOLLOW;
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return lookup_flags;
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}
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/**
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* filp_open - open file and return file pointer
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*
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* @filename: path to open
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* @flags: open flags as per the open(2) second argument
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* @mode: mode for the new file if O_CREAT is set, else ignored
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*
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* This is the helper to open a file from kernelspace if you really
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* have to. But in generally you should not do this, so please move
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* along, nothing to see here..
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*/
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struct file *filp_open(const char *filename, int flags, int mode)
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{
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struct open_flags op;
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int lookup = build_open_flags(flags, mode, &op);
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return do_filp_open(AT_FDCWD, filename, &op, lookup);
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}
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EXPORT_SYMBOL(filp_open);
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long do_sys_open(int dfd, const char __user *filename, int flags, int mode)
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{
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struct open_flags op;
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int lookup = build_open_flags(flags, mode, &op);
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char *tmp = getname(filename);
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int fd = PTR_ERR(tmp);
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if (!IS_ERR(tmp)) {
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fd = get_unused_fd_flags(flags);
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if (fd >= 0) {
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struct file *f = do_filp_open(dfd, tmp, flags, mode, 0);
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struct file *f = do_filp_open(dfd, tmp, &op, lookup);
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if (IS_ERR(f)) {
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put_unused_fd(fd);
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fd = PTR_ERR(f);
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@ -2205,8 +2205,6 @@ extern struct file *create_read_pipe(struct file *f, int flags);
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extern struct file *create_write_pipe(int flags);
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extern void free_write_pipe(struct file *);
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extern struct file *do_filp_open(int dfd, const char *pathname,
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int open_flag, int mode, int acc_mode);
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extern int may_open(struct path *, int, int);
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extern int kernel_read(struct file *, loff_t, char *, unsigned long);
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