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Diffstat (limited to 'fs/stat.c')
-rw-r--r--fs/stat.c148
1 files changed, 96 insertions, 52 deletions
diff --git a/fs/stat.c b/fs/stat.c
index 12e90e21390..ae0c3cef992 100644
--- a/fs/stat.c
+++ b/fs/stat.c
@@ -4,7 +4,7 @@
* Copyright (C) 1991, 1992 Linus Torvalds
*/
-#include <linux/module.h>
+#include <linux/export.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/file.h>
@@ -27,42 +27,61 @@ void generic_fillattr(struct inode *inode, struct kstat *stat)
stat->uid = inode->i_uid;
stat->gid = inode->i_gid;
stat->rdev = inode->i_rdev;
+ stat->size = i_size_read(inode);
stat->atime = inode->i_atime;
stat->mtime = inode->i_mtime;
stat->ctime = inode->i_ctime;
- stat->size = i_size_read(inode);
- stat->blocks = inode->i_blocks;
stat->blksize = (1 << inode->i_blkbits);
+ stat->blocks = inode->i_blocks;
}
EXPORT_SYMBOL(generic_fillattr);
-int vfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
+/**
+ * vfs_getattr_nosec - getattr without security checks
+ * @path: file to get attributes from
+ * @stat: structure to return attributes in
+ *
+ * Get attributes without calling security_inode_getattr.
+ *
+ * Currently the only caller other than vfs_getattr is internal to the
+ * filehandle lookup code, which uses only the inode number and returns
+ * no attributes to any user. Any other code probably wants
+ * vfs_getattr.
+ */
+int vfs_getattr_nosec(struct path *path, struct kstat *stat)
{
- struct inode *inode = dentry->d_inode;
- int retval;
-
- retval = security_inode_getattr(mnt, dentry);
- if (retval)
- return retval;
+ struct inode *inode = path->dentry->d_inode;
if (inode->i_op->getattr)
- return inode->i_op->getattr(mnt, dentry, stat);
+ return inode->i_op->getattr(path->mnt, path->dentry, stat);
generic_fillattr(inode, stat);
return 0;
}
+EXPORT_SYMBOL(vfs_getattr_nosec);
+
+int vfs_getattr(struct path *path, struct kstat *stat)
+{
+ int retval;
+
+ retval = security_inode_getattr(path->mnt, path->dentry);
+ if (retval)
+ return retval;
+ return vfs_getattr_nosec(path, stat);
+}
+
EXPORT_SYMBOL(vfs_getattr);
int vfs_fstat(unsigned int fd, struct kstat *stat)
{
- struct file *f = fget(fd);
+ struct fd f = fdget_raw(fd);
int error = -EBADF;
- if (f) {
- error = vfs_getattr(f->f_path.mnt, f->f_path.dentry, stat);
- fput(f);
+ if (f.file) {
+ error = vfs_getattr(&f.file->f_path, stat);
+ fdput(f);
}
return error;
}
@@ -73,20 +92,27 @@ int vfs_fstatat(int dfd, const char __user *filename, struct kstat *stat,
{
struct path path;
int error = -EINVAL;
- int lookup_flags = 0;
+ unsigned int lookup_flags = 0;
- if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0)
+ if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT |
+ AT_EMPTY_PATH)) != 0)
goto out;
if (!(flag & AT_SYMLINK_NOFOLLOW))
lookup_flags |= LOOKUP_FOLLOW;
-
+ if (flag & AT_EMPTY_PATH)
+ lookup_flags |= LOOKUP_EMPTY;
+retry:
error = user_path_at(dfd, filename, lookup_flags, &path);
if (error)
goto out;
- error = vfs_getattr(path.mnt, path.dentry, stat);
+ error = vfs_getattr(&path, stat);
path_put(&path);
+ if (retry_estale(error, lookup_flags)) {
+ lookup_flags |= LOOKUP_REVAL;
+ goto retry;
+ }
out:
return error;
}
@@ -134,8 +160,8 @@ static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * sta
tmp.st_nlink = stat->nlink;
if (tmp.st_nlink != stat->nlink)
return -EOVERFLOW;
- SET_UID(tmp.st_uid, stat->uid);
- SET_GID(tmp.st_gid, stat->gid);
+ SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
+ SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
tmp.st_rdev = old_encode_dev(stat->rdev);
#if BITS_PER_LONG == 32
if (stat->size > MAX_NON_LFS)
@@ -187,24 +213,32 @@ SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, stat
#endif /* __ARCH_WANT_OLD_STAT */
+#if BITS_PER_LONG == 32
+# define choose_32_64(a,b) a
+#else
+# define choose_32_64(a,b) b
+#endif
+
+#define valid_dev(x) choose_32_64(old_valid_dev,new_valid_dev)(x)
+#define encode_dev(x) choose_32_64(old_encode_dev,new_encode_dev)(x)
+
+#ifndef INIT_STRUCT_STAT_PADDING
+# define INIT_STRUCT_STAT_PADDING(st) memset(&st, 0, sizeof(st))
+#endif
+
static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf)
{
struct stat tmp;
-#if BITS_PER_LONG == 32
- if (!old_valid_dev(stat->dev) || !old_valid_dev(stat->rdev))
+ if (!valid_dev(stat->dev) || !valid_dev(stat->rdev))
return -EOVERFLOW;
-#else
- if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev))
+#if BITS_PER_LONG == 32
+ if (stat->size > MAX_NON_LFS)
return -EOVERFLOW;
#endif
- memset(&tmp, 0, sizeof(tmp));
-#if BITS_PER_LONG == 32
- tmp.st_dev = old_encode_dev(stat->dev);
-#else
- tmp.st_dev = new_encode_dev(stat->dev);
-#endif
+ INIT_STRUCT_STAT_PADDING(tmp);
+ tmp.st_dev = encode_dev(stat->dev);
tmp.st_ino = stat->ino;
if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
return -EOVERFLOW;
@@ -212,17 +246,9 @@ static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf)
tmp.st_nlink = stat->nlink;
if (tmp.st_nlink != stat->nlink)
return -EOVERFLOW;
- SET_UID(tmp.st_uid, stat->uid);
- SET_GID(tmp.st_gid, stat->gid);
-#if BITS_PER_LONG == 32
- tmp.st_rdev = old_encode_dev(stat->rdev);
-#else
- tmp.st_rdev = new_encode_dev(stat->rdev);
-#endif
-#if BITS_PER_LONG == 32
- if (stat->size > MAX_NON_LFS)
- return -EOVERFLOW;
-#endif
+ SET_UID(tmp.st_uid, from_kuid_munged(current_user_ns(), stat->uid));
+ SET_GID(tmp.st_gid, from_kgid_munged(current_user_ns(), stat->gid));
+ tmp.st_rdev = encode_dev(stat->rdev);
tmp.st_size = stat->size;
tmp.st_atime = stat->atime.tv_sec;
tmp.st_mtime = stat->mtime.tv_sec;
@@ -291,24 +317,31 @@ SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,
{
struct path path;
int error;
+ int empty = 0;
+ unsigned int lookup_flags = LOOKUP_EMPTY;
if (bufsiz <= 0)
return -EINVAL;
- error = user_path_at(dfd, pathname, 0, &path);
+retry:
+ error = user_path_at_empty(dfd, pathname, lookup_flags, &path, &empty);
if (!error) {
struct inode *inode = path.dentry->d_inode;
- error = -EINVAL;
+ error = empty ? -ENOENT : -EINVAL;
if (inode->i_op->readlink) {
error = security_inode_readlink(path.dentry);
if (!error) {
- touch_atime(path.mnt, path.dentry);
+ touch_atime(&path);
error = inode->i_op->readlink(path.dentry,
buf, bufsiz);
}
}
path_put(&path);
+ if (retry_estale(error, lookup_flags)) {
+ lookup_flags |= LOOKUP_REVAL;
+ goto retry;
+ }
}
return error;
}
@@ -321,13 +354,17 @@ SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf,
/* ---------- LFS-64 ----------- */
-#ifdef __ARCH_WANT_STAT64
+#if defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_COMPAT_STAT64)
+
+#ifndef INIT_STRUCT_STAT64_PADDING
+# define INIT_STRUCT_STAT64_PADDING(st) memset(&st, 0, sizeof(st))
+#endif
static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf)
{
struct stat64 tmp;
- memset(&tmp, 0, sizeof(struct stat64));
+ INIT_STRUCT_STAT64_PADDING(tmp);
#ifdef CONFIG_MIPS
/* mips has weird padding, so we don't get 64 bits there */
if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev))
@@ -346,8 +383,8 @@ static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf)
#endif
tmp.st_mode = stat->mode;
tmp.st_nlink = stat->nlink;
- tmp.st_uid = stat->uid;
- tmp.st_gid = stat->gid;
+ tmp.st_uid = from_kuid_munged(current_user_ns(), stat->uid);
+ tmp.st_gid = from_kgid_munged(current_user_ns(), stat->gid);
tmp.st_atime = stat->atime.tv_sec;
tmp.st_atime_nsec = stat->atime.tv_nsec;
tmp.st_mtime = stat->mtime.tv_sec;
@@ -406,7 +443,7 @@ SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename,
return error;
return cp_new_stat64(&stat, statbuf);
}
-#endif /* __ARCH_WANT_STAT64 */
+#endif /* __ARCH_WANT_STAT64 || __ARCH_WANT_COMPAT_STAT64 */
/* Caller is here responsible for sufficient locking (ie. inode->i_lock) */
void __inode_add_bytes(struct inode *inode, loff_t bytes)
@@ -429,9 +466,8 @@ void inode_add_bytes(struct inode *inode, loff_t bytes)
EXPORT_SYMBOL(inode_add_bytes);
-void inode_sub_bytes(struct inode *inode, loff_t bytes)
+void __inode_sub_bytes(struct inode *inode, loff_t bytes)
{
- spin_lock(&inode->i_lock);
inode->i_blocks -= bytes >> 9;
bytes &= 511;
if (inode->i_bytes < bytes) {
@@ -439,6 +475,14 @@ void inode_sub_bytes(struct inode *inode, loff_t bytes)
inode->i_bytes += 512;
}
inode->i_bytes -= bytes;
+}
+
+EXPORT_SYMBOL(__inode_sub_bytes);
+
+void inode_sub_bytes(struct inode *inode, loff_t bytes)
+{
+ spin_lock(&inode->i_lock);
+ __inode_sub_bytes(inode, bytes);
spin_unlock(&inode->i_lock);
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-05 00:26:04 +0000