cregit-Linux how code gets into the kernel

Release 4.12 fs/statfs.c

Directory: fs
#include <linux/syscalls.h>
#include <linux/export.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/statfs.h>
#include <linux/security.h>
#include <linux/uaccess.h>
#include <linux/compat.h>
#include "internal.h"


static int flags_by_mnt(int mnt_flags) { int flags = 0; if (mnt_flags & MNT_READONLY) flags |= ST_RDONLY; if (mnt_flags & MNT_NOSUID) flags |= ST_NOSUID; if (mnt_flags & MNT_NODEV) flags |= ST_NODEV; if (mnt_flags & MNT_NOEXEC) flags |= ST_NOEXEC; if (mnt_flags & MNT_NOATIME) flags |= ST_NOATIME; if (mnt_flags & MNT_NODIRATIME) flags |= ST_NODIRATIME; if (mnt_flags & MNT_RELATIME) flags |= ST_RELATIME; return flags; }

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Christoph Hellwig87100.00%1100.00%
Total87100.00%1100.00%


static int flags_by_sb(int s_flags) { int flags = 0; if (s_flags & MS_SYNCHRONOUS) flags |= ST_SYNCHRONOUS; if (s_flags & MS_MANDLOCK) flags |= ST_MANDLOCK; return flags; }

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Christoph Hellwig37100.00%1100.00%
Total37100.00%1100.00%


static int calculate_f_flags(struct vfsmount *mnt) { return ST_VALID | flags_by_mnt(mnt->mnt_flags) | flags_by_sb(mnt->mnt_sb->s_flags); }

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Christoph Hellwig30100.00%1100.00%
Total30100.00%1100.00%


static int statfs_by_dentry(struct dentry *dentry, struct kstatfs *buf) { int retval; if (!dentry->d_sb->s_op->statfs) return -ENOSYS; memset(buf, 0, sizeof(*buf)); retval = security_sb_statfs(dentry); if (retval) return retval; retval = dentry->d_sb->s_op->statfs(dentry, buf); if (retval == 0 && buf->f_frsize == 0) buf->f_frsize = buf->f_bsize; return retval; }

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Al Viro9393.94%266.67%
Christoph Hellwig66.06%133.33%
Total99100.00%3100.00%


int vfs_statfs(const struct path *path, struct kstatfs *buf) { int error; error = statfs_by_dentry(path->dentry, buf); if (!error) buf->f_flags = calculate_f_flags(path->mnt); return error; }

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Christoph Hellwig4897.96%266.67%
Al Viro12.04%133.33%
Total49100.00%3100.00%

EXPORT_SYMBOL(vfs_statfs);
int user_statfs(const char __user *pathname, struct kstatfs *st) { struct path path; int error; unsigned int lookup_flags = LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT; retry: error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path); if (!error) { error = vfs_statfs(&path, st); path_put(&path); if (retry_estale(error, lookup_flags)) { lookup_flags |= LOOKUP_REVAL; goto retry; } } return error; }

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Al Viro5459.34%240.00%
Jeff Layton3235.16%120.00%
Dan McGee44.40%120.00%
Christoph Hellwig11.10%120.00%
Total91100.00%5100.00%


int fd_statfs(int fd, struct kstatfs *st) { struct fd f = fdget_raw(fd); int error = -EBADF; if (f.file) { error = vfs_statfs(&f.file->f_path, st); fdput(f); } return error; }

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Al Viro5798.28%375.00%
Linus Torvalds11.72%125.00%
Total58100.00%4100.00%


static int do_statfs_native(struct kstatfs *st, struct statfs __user *p) { struct statfs buf; if (sizeof(buf) == sizeof(*st)) memcpy(&buf, st, sizeof(*st)); else { if (sizeof buf.f_blocks == 4) { if ((st->f_blocks | st->f_bfree | st->f_bavail | st->f_bsize | st->f_frsize) & 0xffffffff00000000ULL) return -EOVERFLOW; /* * f_files and f_ffree may be -1; it's okay to stuff * that into 32 bits */ if (st->f_files != -1 && (st->f_files & 0xffffffff00000000ULL)) return -EOVERFLOW; if (st->f_ffree != -1 && (st->f_ffree & 0xffffffff00000000ULL)) return -EOVERFLOW; } buf.f_type = st->f_type; buf.f_bsize = st->f_bsize; buf.f_blocks = st->f_blocks; buf.f_bfree = st->f_bfree; buf.f_bavail = st->f_bavail; buf.f_files = st->f_files; buf.f_ffree = st->f_ffree; buf.f_fsid = st->f_fsid; buf.f_namelen = st->f_namelen; buf.f_frsize = st->f_frsize; buf.f_flags = st->f_flags; memset(buf.f_spare, 0, sizeof(buf.f_spare)); } if (copy_to_user(p, &buf, sizeof(buf))) return -EFAULT; return 0; }

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Al Viro25597.70%266.67%
Christoph Hellwig62.30%133.33%
Total261100.00%3100.00%


static int do_statfs64(struct kstatfs *st, struct statfs64 __user *p) { struct statfs64 buf; if (sizeof(buf) == sizeof(*st)) memcpy(&buf, st, sizeof(*st)); else { buf.f_type = st->f_type; buf.f_bsize = st->f_bsize; buf.f_blocks = st->f_blocks; buf.f_bfree = st->f_bfree; buf.f_bavail = st->f_bavail; buf.f_files = st->f_files; buf.f_ffree = st->f_ffree; buf.f_fsid = st->f_fsid; buf.f_namelen = st->f_namelen; buf.f_frsize = st->f_frsize; buf.f_flags = st->f_flags; memset(buf.f_spare, 0, sizeof(buf.f_spare)); } if (copy_to_user(p, &buf, sizeof(buf))) return -EFAULT; return 0; }

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Al Viro17096.05%250.00%
Christoph Hellwig73.95%250.00%
Total177100.00%4100.00%

SYSCALL_DEFINE2(statfs, const char __user *, pathname, struct statfs __user *, buf) { struct kstatfs st; int error = user_statfs(pathname, &st); if (!error) error = do_statfs_native(&st, buf); return error; } SYSCALL_DEFINE3(statfs64, const char __user *, pathname, size_t, sz, struct statfs64 __user *, buf) { struct kstatfs st; int error; if (sz != sizeof(*buf)) return -EINVAL; error = user_statfs(pathname, &st); if (!error) error = do_statfs64(&st, buf); return error; } SYSCALL_DEFINE2(fstatfs, unsigned int, fd, struct statfs __user *, buf) { struct kstatfs st; int error = fd_statfs(fd, &st); if (!error) error = do_statfs_native(&st, buf); return error; } SYSCALL_DEFINE3(fstatfs64, unsigned int, fd, size_t, sz, struct statfs64 __user *, buf) { struct kstatfs st; int error; if (sz != sizeof(*buf)) return -EINVAL; error = fd_statfs(fd, &st); if (!error) error = do_statfs64(&st, buf); return error; }
int vfs_ustat(dev_t dev, struct kstatfs *sbuf) { struct super_block *s = user_get_super(dev); int err; if (!s) return -EINVAL; err = statfs_by_dentry(s->s_root, sbuf); drop_super(s); return err; }

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Al Viro54100.00%1100.00%
Total54100.00%1100.00%

SYSCALL_DEFINE2(ustat, unsigned, dev, struct ustat __user *, ubuf) { struct ustat tmp; struct kstatfs sbuf; int err = vfs_ustat(new_decode_dev(dev), &sbuf); if (err) return err; memset(&tmp,0,sizeof(struct ustat)); tmp.f_tfree = sbuf.f_bfree; tmp.f_tinode = sbuf.f_ffree; return copy_to_user(ubuf, &tmp, sizeof(struct ustat)) ? -EFAULT : 0; } #ifdef CONFIG_COMPAT
static int put_compat_statfs(struct compat_statfs __user *ubuf, struct kstatfs *kbuf) { if (sizeof ubuf->f_blocks == 4) { if ((kbuf->f_blocks | kbuf->f_bfree | kbuf->f_bavail | kbuf->f_bsize | kbuf->f_frsize) & 0xffffffff00000000ULL) return -EOVERFLOW; /* f_files and f_ffree may be -1; it's okay * to stuff that into 32 bits */ if (kbuf->f_files != 0xffffffffffffffffULL && (kbuf->f_files & 0xffffffff00000000ULL)) return -EOVERFLOW; if (kbuf->f_ffree != 0xffffffffffffffffULL && (kbuf->f_ffree & 0xffffffff00000000ULL)) return -EOVERFLOW; } if (!access_ok(VERIFY_WRITE, ubuf, sizeof(*ubuf)) || __put_user(kbuf->f_type, &ubuf->f_type) || __put_user(kbuf->f_bsize, &ubuf->f_bsize) || __put_user(kbuf->f_blocks, &ubuf->f_blocks) || __put_user(kbuf->f_bfree, &ubuf->f_bfree) || __put_user(kbuf->f_bavail, &ubuf->f_bavail) || __put_user(kbuf->f_files, &ubuf->f_files) || __put_user(kbuf->f_ffree, &ubuf->f_ffree) || __put_user(kbuf->f_namelen, &ubuf->f_namelen) || __put_user(kbuf->f_fsid.val[0], &ubuf->f_fsid.val[0]) || __put_user(kbuf->f_fsid.val[1], &ubuf->f_fsid.val[1]) || __put_user(kbuf->f_frsize, &ubuf->f_frsize) || __put_user(kbuf->f_flags, &ubuf->f_flags) || __clear_user(ubuf->f_spare, sizeof(ubuf->f_spare))) return -EFAULT; return 0; }

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Al Viro300100.00%1100.00%
Total300100.00%1100.00%

/* * The following statfs calls are copies of code from fs/statfs.c and * should be checked against those from time to time */ COMPAT_SYSCALL_DEFINE2(statfs, const char __user *, pathname, struct compat_statfs __user *, buf) { struct kstatfs tmp; int error = user_statfs(pathname, &tmp); if (!error) error = put_compat_statfs(buf, &tmp); return error; } COMPAT_SYSCALL_DEFINE2(fstatfs, unsigned int, fd, struct compat_statfs __user *, buf) { struct kstatfs tmp; int error = fd_statfs(fd, &tmp); if (!error) error = put_compat_statfs(buf, &tmp); return error; }
static int put_compat_statfs64(struct compat_statfs64 __user *ubuf, struct kstatfs *kbuf) { if (sizeof(ubuf->f_bsize) == 4) { if ((kbuf->f_type | kbuf->f_bsize | kbuf->f_namelen | kbuf->f_frsize | kbuf->f_flags) & 0xffffffff00000000ULL) return -EOVERFLOW; /* f_files and f_ffree may be -1; it's okay * to stuff that into 32 bits */ if (kbuf->f_files != 0xffffffffffffffffULL && (kbuf->f_files & 0xffffffff00000000ULL)) return -EOVERFLOW; if (kbuf->f_ffree != 0xffffffffffffffffULL && (kbuf->f_ffree & 0xffffffff00000000ULL)) return -EOVERFLOW; } if (!access_ok(VERIFY_WRITE, ubuf, sizeof(*ubuf)) || __put_user(kbuf->f_type, &ubuf->f_type) || __put_user(kbuf->f_bsize, &ubuf->f_bsize) || __put_user(kbuf->f_blocks, &ubuf->f_blocks) || __put_user(kbuf->f_bfree, &ubuf->f_bfree) || __put_user(kbuf->f_bavail, &ubuf->f_bavail) || __put_user(kbuf->f_files, &ubuf->f_files) || __put_user(kbuf->f_ffree, &ubuf->f_ffree) || __put_user(kbuf->f_namelen, &ubuf->f_namelen) || __put_user(kbuf->f_fsid.val[0], &ubuf->f_fsid.val[0]) || __put_user(kbuf->f_fsid.val[1], &ubuf->f_fsid.val[1]) || __put_user(kbuf->f_frsize, &ubuf->f_frsize) || __put_user(kbuf->f_flags, &ubuf->f_flags) || __clear_user(ubuf->f_spare, sizeof(ubuf->f_spare))) return -EFAULT; return 0; }

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Al Viro302100.00%1100.00%
Total302100.00%1100.00%

COMPAT_SYSCALL_DEFINE3(statfs64, const char __user *, pathname, compat_size_t, sz, struct compat_statfs64 __user *, buf) { struct kstatfs tmp; int error; if (sz != sizeof(*buf)) return -EINVAL; error = user_statfs(pathname, &tmp); if (!error) error = put_compat_statfs64(buf, &tmp); return error; } COMPAT_SYSCALL_DEFINE3(fstatfs64, unsigned int, fd, compat_size_t, sz, struct compat_statfs64 __user *, buf) { struct kstatfs tmp; int error; if (sz != sizeof(*buf)) return -EINVAL; error = fd_statfs(fd, &tmp); if (!error) error = put_compat_statfs64(buf, &tmp); 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. */ COMPAT_SYSCALL_DEFINE2(ustat, unsigned, dev, struct compat_ustat __user *, u) { struct compat_ustat tmp; struct kstatfs sbuf; int err = vfs_ustat(new_decode_dev(dev), &sbuf); 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; } #endif

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Al Viro196487.87%650.00%
Christoph Hellwig23310.43%216.67%
Jeff Layton321.43%18.33%
Dan McGee40.18%18.33%
Linus Torvalds10.04%18.33%
Paul Gortmaker10.04%18.33%
Total2235100.00%12100.00%
Directory: fs
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