From 8c7493aa3e9ae90f90196f4d4c1398ad143cba7b Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Fri, 31 Mar 2017 18:31:32 +0100 Subject: statx: reject unknown flags when using NULL path The statx() system call currently accepts unknown flags when called with a NULL path to operate on a file descriptor. Left unchanged, this could make it hard to introduce new query flags in the future, since applications may not be able to tell whether a given flag is supported. Fix this by failing the system call with EINVAL if any flags other than KSTAT_QUERY_FLAGS are specified in combination with a NULL path. Arguably, we could still permit known lookup-related flags such as AT_SYMLINK_NOFOLLOW. However, that would be inconsistent with how sys_utimensat() behaves when passed a NULL path, which seems to be the closest precedent. And given that the NULL path case is (I believe) mainly intended to be used to implement a wrapper function like fstatx() that doesn't have a path argument, I think rejecting lookup-related flags too is probably the best choice. Signed-off-by: Eric Biggers Signed-off-by: David Howells Signed-off-by: Al Viro --- fs/stat.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'fs') diff --git a/fs/stat.c b/fs/stat.c index fa0be59340cc..df484a60846d 100644 --- a/fs/stat.c +++ b/fs/stat.c @@ -130,9 +130,13 @@ EXPORT_SYMBOL(vfs_getattr); int vfs_statx_fd(unsigned int fd, struct kstat *stat, u32 request_mask, unsigned int query_flags) { - struct fd f = fdget_raw(fd); + struct fd f; int error = -EBADF; + if (query_flags & ~KSTAT_QUERY_FLAGS) + return -EINVAL; + + f = fdget_raw(fd); if (f.file) { error = vfs_getattr(&f.file->f_path, stat, request_mask, query_flags); -- cgit v1.2.3-59-g8ed1b From b15fb70b82299f92bb8d591c9d1731cb23fa8290 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Fri, 31 Mar 2017 18:31:40 +0100 Subject: statx: remove incorrect part of vfs_statx() comment request_mask and query_flags are function arguments, not passed in struct kstat. So remove the part of the comment which claims otherwise. This was apparently left over from an earlier version of the statx patch. Signed-off-by: Eric Biggers Signed-off-by: David Howells Reviewed-by: Christoph Hellwig Signed-off-by: Al Viro --- fs/stat.c | 3 --- 1 file changed, 3 deletions(-) (limited to 'fs') diff --git a/fs/stat.c b/fs/stat.c index df484a60846d..b792dd201c31 100644 --- a/fs/stat.c +++ b/fs/stat.c @@ -159,9 +159,6 @@ EXPORT_SYMBOL(vfs_statx_fd); * Additionally, the use of AT_SYMLINK_NOFOLLOW in flags will prevent a symlink * at the given name from being referenced. * - * The caller must have preset stat->request_mask as for vfs_getattr(). The - * flags are also used to load up stat->query_flags. - * * 0 will be returned on success, and a -ve error code if unsuccessful. */ int vfs_statx(int dfd, const char __user *filename, int flags, -- cgit v1.2.3-59-g8ed1b From 64bd72048a2ac07efed70debe606a1c6e5e03554 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Fri, 31 Mar 2017 18:31:48 +0100 Subject: statx: optimize copy of struct statx to userspace I found that statx() was significantly slower than stat(). As a microbenchmark, I compared 10,000,000 invocations of fstat() on a tmpfs file to the same with statx() passed a NULL path: $ time ./stat_benchmark real 0m1.464s user 0m0.275s sys 0m1.187s $ time ./statx_benchmark real 0m5.530s user 0m0.281s sys 0m5.247s statx is expected to be a little slower than stat because struct statx is larger than struct stat, but not by *that* much. It turns out that most of the overhead was in copying struct statx to userspace, mostly in all the stac/clac instructions that got generated for each __put_user() call. (This was on x86_64, but some other architectures, e.g. arm64, have something similar now too.) stat() instead initializes its struct on the stack and copies it to userspace with a single call to copy_to_user(). This turns out to be much faster, and changing statx to do this makes it almost as fast as stat: $ time ./statx_benchmark real 0m1.624s user 0m0.270s sys 0m1.354s For zeroing the reserved fields, start by zeroing the full struct with memset. This makes it clear that every byte copied to userspace is initialized, even implicit padding bytes (though there are none currently). In the scenarios I tested, it also performed the same as a designated initializer. Manually initializing each field was still slightly faster, but would have been more error-prone and less verifiable. Also rename statx_set_result() to cp_statx() for consistency with cp_old_stat() et al., and make it noinline so that struct statx doesn't add to the stack usage during the main portion of the syscall execution. Signed-off-by: Eric Biggers Signed-off-by: David Howells Signed-off-by: Al Viro --- fs/stat.c | 74 +++++++++++++++++++++++++++------------------------------------ 1 file changed, 32 insertions(+), 42 deletions(-) (limited to 'fs') diff --git a/fs/stat.c b/fs/stat.c index b792dd201c31..ab27f2868588 100644 --- a/fs/stat.c +++ b/fs/stat.c @@ -510,46 +510,37 @@ SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename, } #endif /* __ARCH_WANT_STAT64 || __ARCH_WANT_COMPAT_STAT64 */ -static inline int __put_timestamp(struct timespec *kts, - struct statx_timestamp __user *uts) +static noinline_for_stack int +cp_statx(const struct kstat *stat, struct statx __user *buffer) { - return (__put_user(kts->tv_sec, &uts->tv_sec ) || - __put_user(kts->tv_nsec, &uts->tv_nsec ) || - __put_user(0, &uts->__reserved )); -} - -/* - * Set the statx results. - */ -static long statx_set_result(struct kstat *stat, struct statx __user *buffer) -{ - uid_t uid = from_kuid_munged(current_user_ns(), stat->uid); - gid_t gid = from_kgid_munged(current_user_ns(), stat->gid); - - if (__put_user(stat->result_mask, &buffer->stx_mask ) || - __put_user(stat->mode, &buffer->stx_mode ) || - __clear_user(&buffer->__spare0, sizeof(buffer->__spare0)) || - __put_user(stat->nlink, &buffer->stx_nlink ) || - __put_user(uid, &buffer->stx_uid ) || - __put_user(gid, &buffer->stx_gid ) || - __put_user(stat->attributes, &buffer->stx_attributes ) || - __put_user(stat->blksize, &buffer->stx_blksize ) || - __put_user(MAJOR(stat->rdev), &buffer->stx_rdev_major ) || - __put_user(MINOR(stat->rdev), &buffer->stx_rdev_minor ) || - __put_user(MAJOR(stat->dev), &buffer->stx_dev_major ) || - __put_user(MINOR(stat->dev), &buffer->stx_dev_minor ) || - __put_timestamp(&stat->atime, &buffer->stx_atime ) || - __put_timestamp(&stat->btime, &buffer->stx_btime ) || - __put_timestamp(&stat->ctime, &buffer->stx_ctime ) || - __put_timestamp(&stat->mtime, &buffer->stx_mtime ) || - __put_user(stat->ino, &buffer->stx_ino ) || - __put_user(stat->size, &buffer->stx_size ) || - __put_user(stat->blocks, &buffer->stx_blocks ) || - __clear_user(&buffer->__spare1, sizeof(buffer->__spare1)) || - __clear_user(&buffer->__spare2, sizeof(buffer->__spare2))) - return -EFAULT; - - return 0; + struct statx tmp; + + memset(&tmp, 0, sizeof(tmp)); + + tmp.stx_mask = stat->result_mask; + tmp.stx_blksize = stat->blksize; + tmp.stx_attributes = stat->attributes; + tmp.stx_nlink = stat->nlink; + tmp.stx_uid = from_kuid_munged(current_user_ns(), stat->uid); + tmp.stx_gid = from_kgid_munged(current_user_ns(), stat->gid); + tmp.stx_mode = stat->mode; + tmp.stx_ino = stat->ino; + tmp.stx_size = stat->size; + tmp.stx_blocks = stat->blocks; + tmp.stx_atime.tv_sec = stat->atime.tv_sec; + tmp.stx_atime.tv_nsec = stat->atime.tv_nsec; + tmp.stx_btime.tv_sec = stat->btime.tv_sec; + tmp.stx_btime.tv_nsec = stat->btime.tv_nsec; + tmp.stx_ctime.tv_sec = stat->ctime.tv_sec; + tmp.stx_ctime.tv_nsec = stat->ctime.tv_nsec; + tmp.stx_mtime.tv_sec = stat->mtime.tv_sec; + tmp.stx_mtime.tv_nsec = stat->mtime.tv_nsec; + tmp.stx_rdev_major = MAJOR(stat->rdev); + tmp.stx_rdev_minor = MINOR(stat->rdev); + tmp.stx_dev_major = MAJOR(stat->dev); + tmp.stx_dev_minor = MINOR(stat->dev); + + return copy_to_user(buffer, &tmp, sizeof(tmp)) ? -EFAULT : 0; } /** @@ -573,8 +564,6 @@ SYSCALL_DEFINE5(statx, if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE) return -EINVAL; - if (!access_ok(VERIFY_WRITE, buffer, sizeof(*buffer))) - return -EFAULT; if (filename) error = vfs_statx(dfd, filename, flags, &stat, mask); @@ -582,7 +571,8 @@ SYSCALL_DEFINE5(statx, error = vfs_statx_fd(dfd, &stat, mask, flags); if (error) return error; - return statx_set_result(&stat, buffer); + + return cp_statx(&stat, buffer); } /* Caller is here responsible for sufficient locking (ie. inode->i_lock) */ -- cgit v1.2.3-59-g8ed1b From 99652ea56a4186bc5bf8a3721c5353f41b35ebcb Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 31 Mar 2017 18:31:56 +0100 Subject: ext4: Add statx support Return enhanced file attributes from the Ext4 filesystem. This includes the following: (1) The inode creation time (i_crtime) as stx_btime, setting STATX_BTIME. (2) Certain FS_xxx_FL flags are mapped to stx_attribute flags. This requires that all ext4 inodes have a getattr call, not just some of them, so to this end, split the ext4_getattr() function and only call part of it where appropriate. Example output: [root@andromeda ~]# touch foo [root@andromeda ~]# chattr +ai foo [root@andromeda ~]# /tmp/test-statx foo statx(foo) = 0 results=fff Size: 0 Blocks: 0 IO Block: 4096 regular file Device: 08:12 Inode: 2101950 Links: 1 Access: (0644/-rw-r--r--) Uid: 0 Gid: 0 Access: 2016-02-11 17:08:29.031795451+0000 Modify: 2016-02-11 17:08:29.031795451+0000 Change: 2016-02-11 17:11:11.987790114+0000 Birth: 2016-02-11 17:08:29.031795451+0000 Attributes: 0000000000000030 (-------- -------- -------- -------- -------- -------- -------- --ai----) Signed-off-by: David Howells Signed-off-by: Al Viro --- fs/ext4/ext4.h | 1 + fs/ext4/file.c | 2 +- fs/ext4/inode.c | 35 ++++++++++++++++++++++++++++++++--- fs/ext4/namei.c | 2 ++ fs/ext4/symlink.c | 3 +++ 5 files changed, 39 insertions(+), 4 deletions(-) (limited to 'fs') diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index f493af666591..fb69ee2388db 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -2466,6 +2466,7 @@ extern int ext4_setattr(struct dentry *, struct iattr *); extern int ext4_getattr(const struct path *, struct kstat *, u32, unsigned int); extern void ext4_evict_inode(struct inode *); extern void ext4_clear_inode(struct inode *); +extern int ext4_file_getattr(const struct path *, struct kstat *, u32, unsigned int); extern int ext4_sync_inode(handle_t *, struct inode *); extern void ext4_dirty_inode(struct inode *, int); extern int ext4_change_inode_journal_flag(struct inode *, int); diff --git a/fs/ext4/file.c b/fs/ext4/file.c index 8210c1f43556..cefa9835f275 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -744,7 +744,7 @@ const struct file_operations ext4_file_operations = { const struct inode_operations ext4_file_inode_operations = { .setattr = ext4_setattr, - .getattr = ext4_getattr, + .getattr = ext4_file_getattr, .listxattr = ext4_listxattr, .get_acl = ext4_get_acl, .set_acl = ext4_set_acl, diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 4247d8d25687..5d02b922afa3 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -5390,11 +5390,40 @@ err_out: int ext4_getattr(const struct path *path, struct kstat *stat, u32 request_mask, unsigned int query_flags) { - struct inode *inode; - unsigned long long delalloc_blocks; + struct inode *inode = d_inode(path->dentry); + struct ext4_inode *raw_inode; + struct ext4_inode_info *ei = EXT4_I(inode); + unsigned int flags; + + if (EXT4_FITS_IN_INODE(raw_inode, ei, i_crtime)) { + stat->result_mask |= STATX_BTIME; + stat->btime.tv_sec = ei->i_crtime.tv_sec; + stat->btime.tv_nsec = ei->i_crtime.tv_nsec; + } + + flags = ei->i_flags & EXT4_FL_USER_VISIBLE; + if (flags & EXT4_APPEND_FL) + stat->attributes |= STATX_ATTR_APPEND; + if (flags & EXT4_COMPR_FL) + stat->attributes |= STATX_ATTR_COMPRESSED; + if (flags & EXT4_ENCRYPT_FL) + stat->attributes |= STATX_ATTR_ENCRYPTED; + if (flags & EXT4_IMMUTABLE_FL) + stat->attributes |= STATX_ATTR_IMMUTABLE; + if (flags & EXT4_NODUMP_FL) + stat->attributes |= STATX_ATTR_NODUMP; - inode = d_inode(path->dentry); generic_fillattr(inode, stat); + return 0; +} + +int ext4_file_getattr(const struct path *path, struct kstat *stat, + u32 request_mask, unsigned int query_flags) +{ + struct inode *inode = d_inode(path->dentry); + u64 delalloc_blocks; + + ext4_getattr(path, stat, request_mask, query_flags); /* * If there is inline data in the inode, the inode will normally not diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index 6ad612c576fc..07e5e1405771 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -3912,6 +3912,7 @@ const struct inode_operations ext4_dir_inode_operations = { .tmpfile = ext4_tmpfile, .rename = ext4_rename2, .setattr = ext4_setattr, + .getattr = ext4_getattr, .listxattr = ext4_listxattr, .get_acl = ext4_get_acl, .set_acl = ext4_set_acl, @@ -3920,6 +3921,7 @@ const struct inode_operations ext4_dir_inode_operations = { const struct inode_operations ext4_special_inode_operations = { .setattr = ext4_setattr, + .getattr = ext4_getattr, .listxattr = ext4_listxattr, .get_acl = ext4_get_acl, .set_acl = ext4_set_acl, diff --git a/fs/ext4/symlink.c b/fs/ext4/symlink.c index 73b184d161fc..5c8fc53cb0e5 100644 --- a/fs/ext4/symlink.c +++ b/fs/ext4/symlink.c @@ -85,17 +85,20 @@ errout: const struct inode_operations ext4_encrypted_symlink_inode_operations = { .get_link = ext4_encrypted_get_link, .setattr = ext4_setattr, + .getattr = ext4_getattr, .listxattr = ext4_listxattr, }; const struct inode_operations ext4_symlink_inode_operations = { .get_link = page_get_link, .setattr = ext4_setattr, + .getattr = ext4_getattr, .listxattr = ext4_listxattr, }; const struct inode_operations ext4_fast_symlink_inode_operations = { .get_link = simple_get_link, .setattr = ext4_setattr, + .getattr = ext4_getattr, .listxattr = ext4_listxattr, }; -- cgit v1.2.3-59-g8ed1b From 5f955f26f3d42d04aba65590a32eb70eedb7f37d Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Fri, 31 Mar 2017 18:32:03 +0100 Subject: xfs: report crtime and attribute flags to statx statx has the ability to report inode creation times and inode flags, so hook up di_crtime and di_flags to that functionality. Signed-off-by: Darrick J. Wong Signed-off-by: David Howells Signed-off-by: Al Viro --- fs/xfs/xfs_iops.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'fs') diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c index 229cc6a6d8ef..ebfc13350f9a 100644 --- a/fs/xfs/xfs_iops.c +++ b/fs/xfs/xfs_iops.c @@ -516,6 +516,20 @@ xfs_vn_getattr( stat->blocks = XFS_FSB_TO_BB(mp, ip->i_d.di_nblocks + ip->i_delayed_blks); + if (ip->i_d.di_version == 3) { + if (request_mask & STATX_BTIME) { + stat->result_mask |= STATX_BTIME; + stat->btime.tv_sec = ip->i_d.di_crtime.t_sec; + stat->btime.tv_nsec = ip->i_d.di_crtime.t_nsec; + } + } + + if (ip->i_d.di_flags & XFS_DIFLAG_IMMUTABLE) + stat->attributes |= STATX_ATTR_IMMUTABLE; + if (ip->i_d.di_flags & XFS_DIFLAG_APPEND) + stat->attributes |= STATX_ATTR_APPEND; + if (ip->i_d.di_flags & XFS_DIFLAG_NODUMP) + stat->attributes |= STATX_ATTR_NODUMP; switch (inode->i_mode & S_IFMT) { case S_IFBLK: -- cgit v1.2.3-59-g8ed1b From 47071aee6a1956524b9929b3b821f6d2f8cae23c Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 31 Mar 2017 18:32:10 +0100 Subject: statx: Reserve the top bit of the mask for future struct expansion Reserve the top bit of the mask for future expansion of the statx struct and give an error if statx() sees it set. All the other bits are ignored if we see them set but don't support the bit; we just clear the bit in the returned mask. Signed-off-by: David Howells Signed-off-by: Al Viro --- fs/stat.c | 2 ++ include/uapi/linux/stat.h | 1 + 2 files changed, 3 insertions(+) (limited to 'fs') diff --git a/fs/stat.c b/fs/stat.c index ab27f2868588..0c7e6cdc435c 100644 --- a/fs/stat.c +++ b/fs/stat.c @@ -562,6 +562,8 @@ SYSCALL_DEFINE5(statx, struct kstat stat; int error; + if (mask & STATX__RESERVED) + return -EINVAL; if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE) return -EINVAL; diff --git a/include/uapi/linux/stat.h b/include/uapi/linux/stat.h index 51a6b86e3700..0869b9eaa8ce 100644 --- a/include/uapi/linux/stat.h +++ b/include/uapi/linux/stat.h @@ -152,6 +152,7 @@ struct statx { #define STATX_BASIC_STATS 0x000007ffU /* The stuff in the normal stat struct */ #define STATX_BTIME 0x00000800U /* Want/got stx_btime */ #define STATX_ALL 0x00000fffU /* All currently supported flags */ +#define STATX__RESERVED 0x80000000U /* Reserved for future struct statx expansion */ /* * Attributes to be found in stx_attributes -- cgit v1.2.3-59-g8ed1b From 3209f68b3ca4667069923a325c88b21131bfdf9f Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 31 Mar 2017 18:32:17 +0100 Subject: statx: Include a mask for stx_attributes in struct statx Include a mask in struct stat to indicate which bits of stx_attributes the filesystem actually supports. This would also be useful if we add another system call that allows you to do a 'bulk attribute set' and pass in a statx struct with the masks appropriately set to say what you want to set. Signed-off-by: David Howells Signed-off-by: Al Viro --- fs/ext4/inode.c | 6 ++++++ fs/stat.c | 1 + include/linux/stat.h | 1 + include/uapi/linux/stat.h | 4 ++-- samples/statx/test-statx.c | 12 ++++++++---- 5 files changed, 18 insertions(+), 6 deletions(-) (limited to 'fs') diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 5d02b922afa3..b9ffa9f4191f 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -5413,6 +5413,12 @@ int ext4_getattr(const struct path *path, struct kstat *stat, if (flags & EXT4_NODUMP_FL) stat->attributes |= STATX_ATTR_NODUMP; + stat->attributes_mask |= (STATX_ATTR_APPEND | + STATX_ATTR_COMPRESSED | + STATX_ATTR_ENCRYPTED | + STATX_ATTR_IMMUTABLE | + STATX_ATTR_NODUMP); + generic_fillattr(inode, stat); return 0; } diff --git a/fs/stat.c b/fs/stat.c index 0c7e6cdc435c..c6c963b2546b 100644 --- a/fs/stat.c +++ b/fs/stat.c @@ -527,6 +527,7 @@ cp_statx(const struct kstat *stat, struct statx __user *buffer) tmp.stx_ino = stat->ino; tmp.stx_size = stat->size; tmp.stx_blocks = stat->blocks; + tmp.stx_attributes_mask = stat->attributes_mask; tmp.stx_atime.tv_sec = stat->atime.tv_sec; tmp.stx_atime.tv_nsec = stat->atime.tv_nsec; tmp.stx_btime.tv_sec = stat->btime.tv_sec; diff --git a/include/linux/stat.h b/include/linux/stat.h index c76e524fb34b..64b6b3aece21 100644 --- a/include/linux/stat.h +++ b/include/linux/stat.h @@ -26,6 +26,7 @@ struct kstat { unsigned int nlink; uint32_t blksize; /* Preferred I/O size */ u64 attributes; + u64 attributes_mask; #define KSTAT_ATTR_FS_IOC_FLAGS \ (STATX_ATTR_COMPRESSED | \ STATX_ATTR_IMMUTABLE | \ diff --git a/include/uapi/linux/stat.h b/include/uapi/linux/stat.h index 0869b9eaa8ce..d538897b8e08 100644 --- a/include/uapi/linux/stat.h +++ b/include/uapi/linux/stat.h @@ -114,7 +114,7 @@ struct statx { __u64 stx_ino; /* Inode number */ __u64 stx_size; /* File size */ __u64 stx_blocks; /* Number of 512-byte blocks allocated */ - __u64 __spare1[1]; + __u64 stx_attributes_mask; /* Mask to show what's supported in stx_attributes */ /* 0x40 */ struct statx_timestamp stx_atime; /* Last access time */ struct statx_timestamp stx_btime; /* File creation time */ @@ -155,7 +155,7 @@ struct statx { #define STATX__RESERVED 0x80000000U /* Reserved for future struct statx expansion */ /* - * Attributes to be found in stx_attributes + * Attributes to be found in stx_attributes and masked in stx_attributes_mask. * * These give information about the features or the state of a file that might * be of use to ordinary userspace programs such as GUIs or ls rather than diff --git a/samples/statx/test-statx.c b/samples/statx/test-statx.c index 8571d766331d..d4d77b09412c 100644 --- a/samples/statx/test-statx.c +++ b/samples/statx/test-statx.c @@ -141,8 +141,8 @@ static void dump_statx(struct statx *stx) if (stx->stx_mask & STATX_BTIME) print_time(" Birth: ", &stx->stx_btime); - if (stx->stx_attributes) { - unsigned char bits; + if (stx->stx_attributes_mask) { + unsigned char bits, mbits; int loop, byte; static char attr_representation[64 + 1] = @@ -160,14 +160,18 @@ static void dump_statx(struct statx *stx) printf("Attributes: %016llx (", stx->stx_attributes); for (byte = 64 - 8; byte >= 0; byte -= 8) { bits = stx->stx_attributes >> byte; + mbits = stx->stx_attributes_mask >> byte; for (loop = 7; loop >= 0; loop--) { int bit = byte + loop; - if (bits & 0x80) + if (!(mbits & 0x80)) + putchar('.'); /* Not supported */ + else if (bits & 0x80) putchar(attr_representation[63 - bit]); else - putchar('-'); + putchar('-'); /* Not set */ bits <<= 1; + mbits <<= 1; } if (byte) putchar(' '); -- cgit v1.2.3-59-g8ed1b