diff options
| author | Christoph Hellwig <hch@lst.de> | 2008-11-28 10:09:09 +0100 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2009-03-27 14:43:57 -0400 |
| commit | 2b1c6bd77d4e6a727ffac8630cd154b2144b751a (patch) | |
| tree | ffc4237dbeed66492124ef2ccecf48db0767531a /fs | |
| parent | ec1ab0abde0af586a59541ad71841f022dcac3e7 (diff) | |
generic compat_sys_ustat
Due to a different size of ino_t ustat needs a compat handler, but
currently only x86 and mips provide one. Add a generic compat_sys_ustat
and switch all architectures over to it. Instead of doing various
user copy hacks compat_sys_ustat just reimplements sys_ustat as
it's trivial. This was suggested by Arnd Bergmann.
Found by Eric Sandeen when running xfstests/017 on ppc64, which causes
stack smashing warnings on RHEL/Fedora due to the too large amount of
data writen by the syscall.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/compat.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/fs/compat.c b/fs/compat.c index d0145ca2757..4e0db94b535 100644 --- a/fs/compat.c +++ b/fs/compat.c @@ -378,6 +378,34 @@ out: return error; } +/* + * This is a copy of sys_ustat, just dealing with a structure layout. + * Given how simple this syscall is that apporach is more maintainable + * than the various conversion hacks. + */ +asmlinkage long compat_sys_ustat(unsigned dev, struct compat_ustat __user *u) +{ + struct super_block *sb; + struct compat_ustat tmp; + struct kstatfs sbuf; + int err; + + sb = user_get_super(new_decode_dev(dev)); + if (!sb) + return -EINVAL; + err = vfs_statfs(sb->s_root, &sbuf); + drop_super(sb); + if (err) + return err; + + memset(&tmp, 0, sizeof(struct compat_ustat)); + tmp.f_tfree = sbuf.f_bfree; + tmp.f_tinode = sbuf.f_ffree; + if (copy_to_user(u, &tmp, sizeof(struct compat_ustat))) + return -EFAULT; + return 0; +} + static int get_compat_flock(struct flock *kfl, struct compat_flock __user *ufl) { if (!access_ok(VERIFY_READ, ufl, sizeof(*ufl)) || |