diff options
Diffstat (limited to 'fs/compat.c')
| -rw-r--r-- | fs/compat.c | 148 |
1 files changed, 131 insertions, 17 deletions
diff --git a/fs/compat.c b/fs/compat.c index d0145ca27572..3f84d5f15889 100644 --- a/fs/compat.c +++ b/fs/compat.c @@ -51,6 +51,7 @@ #include <linux/poll.h> #include <linux/mm.h> #include <linux/eventpoll.h> +#include <linux/fs_struct.h> #include <asm/uaccess.h> #include <asm/mmu_context.h> @@ -378,6 +379,34 @@ 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)) || @@ -1167,16 +1196,12 @@ out: return ret; } -asmlinkage ssize_t -compat_sys_readv(unsigned long fd, const struct compat_iovec __user *vec, unsigned long vlen) +static size_t compat_readv(struct file *file, + const struct compat_iovec __user *vec, + unsigned long vlen, loff_t *pos) { - struct file *file; ssize_t ret = -EBADF; - file = fget(fd); - if (!file) - return -EBADF; - if (!(file->f_mode & FMODE_READ)) goto out; @@ -1184,25 +1209,56 @@ compat_sys_readv(unsigned long fd, const struct compat_iovec __user *vec, unsign if (!file->f_op || (!file->f_op->aio_read && !file->f_op->read)) goto out; - ret = compat_do_readv_writev(READ, file, vec, vlen, &file->f_pos); + ret = compat_do_readv_writev(READ, file, vec, vlen, pos); out: if (ret > 0) add_rchar(current, ret); inc_syscr(current); - fput(file); return ret; } asmlinkage ssize_t -compat_sys_writev(unsigned long fd, const struct compat_iovec __user *vec, unsigned long vlen) +compat_sys_readv(unsigned long fd, const struct compat_iovec __user *vec, + unsigned long vlen) { struct file *file; - ssize_t ret = -EBADF; + int fput_needed; + ssize_t ret; - file = fget(fd); + file = fget_light(fd, &fput_needed); if (!file) return -EBADF; + ret = compat_readv(file, vec, vlen, &file->f_pos); + fput_light(file, fput_needed); + return ret; +} + +asmlinkage ssize_t +compat_sys_preadv(unsigned long fd, const struct compat_iovec __user *vec, + unsigned long vlen, u32 pos_low, u32 pos_high) +{ + loff_t pos = ((loff_t)pos_high << 32) | pos_low; + struct file *file; + int fput_needed; + ssize_t ret; + + if (pos < 0) + return -EINVAL; + file = fget_light(fd, &fput_needed); + if (!file) + return -EBADF; + ret = compat_readv(file, vec, vlen, &pos); + fput_light(file, fput_needed); + return ret; +} + +static size_t compat_writev(struct file *file, + const struct compat_iovec __user *vec, + unsigned long vlen, loff_t *pos) +{ + ssize_t ret = -EBADF; + if (!(file->f_mode & FMODE_WRITE)) goto out; @@ -1210,13 +1266,47 @@ compat_sys_writev(unsigned long fd, const struct compat_iovec __user *vec, unsig if (!file->f_op || (!file->f_op->aio_write && !file->f_op->write)) goto out; - ret = compat_do_readv_writev(WRITE, file, vec, vlen, &file->f_pos); + ret = compat_do_readv_writev(WRITE, file, vec, vlen, pos); out: if (ret > 0) add_wchar(current, ret); inc_syscw(current); - fput(file); + return ret; +} + +asmlinkage ssize_t +compat_sys_writev(unsigned long fd, const struct compat_iovec __user *vec, + unsigned long vlen) +{ + struct file *file; + int fput_needed; + ssize_t ret; + + file = fget_light(fd, &fput_needed); + if (!file) + return -EBADF; + ret = compat_writev(file, vec, vlen, &file->f_pos); + fput_light(file, fput_needed); + return ret; +} + +asmlinkage ssize_t +compat_sys_pwritev(unsigned long fd, const struct compat_iovec __user *vec, + unsigned long vlen, u32 pos_low, u32 pos_high) +{ + loff_t pos = ((loff_t)pos_high << 32) | pos_low; + struct file *file; + int fput_needed; + ssize_t ret; + + if (pos < 0) + return -EINVAL; + file = fget_light(fd, &fput_needed); + if (!file) + return -EBADF; + ret = compat_writev(file, vec, vlen, &pos); + fput_light(file, fput_needed); return ret; } @@ -1392,27 +1482,36 @@ int compat_do_execve(char * filename, { struct linux_binprm *bprm; struct file *file; + struct files_struct *displaced; int retval; + retval = unshare_files(&displaced); + if (retval) + goto out_ret; + retval = -ENOMEM; bprm = kzalloc(sizeof(*bprm), GFP_KERNEL); if (!bprm) - goto out_ret; + goto out_files; retval = mutex_lock_interruptible(¤t->cred_exec_mutex); if (retval < 0) goto out_free; + current->in_execve = 1; retval = -ENOMEM; bprm->cred = prepare_exec_creds(); if (!bprm->cred) goto out_unlock; - check_unsafe_exec(bprm, current->files); + + retval = check_unsafe_exec(bprm); + if (retval) + goto out_unlock; file = open_exec(filename); retval = PTR_ERR(file); if (IS_ERR(file)) - goto out_unlock; + goto out_unmark; sched_exec(); @@ -1454,9 +1553,15 @@ int compat_do_execve(char * filename, goto out; /* execve succeeded */ + write_lock(¤t->fs->lock); + current->fs->in_exec = 0; + write_unlock(¤t->fs->lock); + current->in_execve = 0; mutex_unlock(¤t->cred_exec_mutex); acct_update_integrals(current); free_bprm(bprm); + if (displaced) + put_files_struct(displaced); return retval; out: @@ -1469,12 +1574,21 @@ out_file: fput(bprm->file); } +out_unmark: + write_lock(¤t->fs->lock); + current->fs->in_exec = 0; + write_unlock(¤t->fs->lock); + out_unlock: + current->in_execve = 0; mutex_unlock(¤t->cred_exec_mutex); out_free: free_bprm(bprm); +out_files: + if (displaced) + reset_files_struct(displaced); out_ret: return retval; } |