Safer ABI for O_TMPFILE

[suggested by Rasmus Villemoes] make O_DIRECTORY | O_RDWR part of O_TMPFILE;
that will fail on old kernels in a lot more cases than what I came up with.
And make sure O_CREAT doesn't get there...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2013-07-13 13:26:37 +04:00
parent 4fbeb19d53
commit bb458c644a
6 changed files with 12 additions and 8 deletions

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@ -32,7 +32,7 @@
#define O_SYNC (__O_SYNC|O_DSYNC)
#define O_PATH 040000000
#define O_TMPFILE 0100000000
#define __O_TMPFILE 0100000000
#define F_GETLK 7
#define F_SETLK 8

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@ -20,7 +20,7 @@
#define O_INVISIBLE 004000000 /* invisible I/O, for DMAPI/XDSM */
#define O_PATH 020000000
#define O_TMPFILE 040000000
#define __O_TMPFILE 040000000
#define F_GETLK64 8
#define F_SETLK64 9

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@ -35,7 +35,7 @@
#define O_SYNC (__O_SYNC|O_DSYNC)
#define O_PATH 0x1000000
#define O_TMPFILE 0x2000000
#define __O_TMPFILE 0x2000000
#define F_GETOWN 5 /* for sockets. */
#define F_SETOWN 6 /* for sockets. */

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@ -2977,7 +2977,7 @@ static struct file *path_openat(int dfd, struct filename *pathname,
file->f_flags = op->open_flag;
if (unlikely(file->f_flags & O_TMPFILE)) {
if (unlikely(file->f_flags & __O_TMPFILE)) {
error = do_tmpfile(dfd, pathname, nd, flags, op, file, &opened);
goto out;
}

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@ -840,8 +840,8 @@ static inline int build_open_flags(int flags, umode_t mode, struct open_flags *o
if (flags & __O_SYNC)
flags |= O_DSYNC;
if (flags & O_TMPFILE) {
if (!(flags & O_CREAT))
if (flags & __O_TMPFILE) {
if ((flags & O_TMPFILE_MASK) != O_TMPFILE)
return -EINVAL;
acc_mode = MAY_OPEN | ACC_MODE(flags);
} else if (flags & O_PATH) {

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@ -84,10 +84,14 @@
#define O_PATH 010000000
#endif
#ifndef O_TMPFILE
#define O_TMPFILE 020000000
#ifndef __O_TMPFILE
#define __O_TMPFILE 020000000
#endif
/* a horrid kludge trying to make sure that this will fail on old kernels */
#define O_TMPFILE (__O_TMPFILE | O_DIRECTORY | O_RDWR)
#define O_TMPFILE_MASK (__O_TMPFILE | O_DIRECTORY | O_CREAT | O_ACCMODE)
#ifndef O_NDELAY
#define O_NDELAY O_NONBLOCK
#endif