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-rw-r--r--fs/proc/base.c144
1 files changed, 86 insertions, 58 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c
index ae3c36122..2e83c6a4e 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -40,12 +40,18 @@ int proc_pid_statm(struct task_struct*,char*);
int proc_pid_cpu(struct task_struct*,char*);
/* MOUNT_REWRITE: make all files have non-NULL ->f_vfsmnt (pipefs, sockfs) */
+/* Until then... */
+#define NULL_VFSMNT /* remove as soon as pipefs and sockfs will be there */
+
static int proc_fd_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
{
if (inode->u.proc_i.file) {
- if (inode->u.proc_i.file->f_vfsmnt) {
- *mnt = mntget(inode->u.proc_i.file->f_vfsmnt);
- }
+#ifdef NULL_VFSMNT
+ if (!inode->u.proc_i.file->f_vfsmnt)
+ mntget(*mnt);
+ else
+#endif
+ *mnt = mntget(inode->u.proc_i.file->f_vfsmnt);
*dentry = dget(inode->u.proc_i.file->f_dentry);
return 0;
}
@@ -59,9 +65,11 @@ static int proc_exe_link(struct inode *inode, struct dentry **dentry, struct vfs
int result = -ENOENT;
struct task_struct *task = inode->u.proc_i.task;
- if (!task_lock(task))
- return result;
+ task_lock(task);
mm = task->mm;
+ if (mm)
+ atomic_inc(&mm->mm_users);
+ task_unlock(task);
if (!mm)
goto out;
down(&mm->mmap_sem);
@@ -77,67 +85,81 @@ static int proc_exe_link(struct inode *inode, struct dentry **dentry, struct vfs
vma = vma->vm_next;
}
up(&mm->mmap_sem);
+ mmput(mm);
out:
- task_unlock(task);
return result;
}
static int proc_cwd_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
{
+ struct fs_struct *fs;
int result = -ENOENT;
- if (task_lock(inode->u.proc_i.task)) {
- struct fs_struct *fs = inode->u.proc_i.task->fs;
- if (fs) {
- *mnt = mntget(fs->pwdmnt);
- *dentry = dget(fs->pwd);
- result = 0;
- }
- task_unlock(inode->u.proc_i.task);
+ task_lock(inode->u.proc_i.task);
+ fs = inode->u.proc_i.task->fs;
+ if(fs)
+ atomic_inc(&fs->count);
+ task_unlock(inode->u.proc_i.task);
+ if (fs) {
+ *mnt = mntget(fs->pwdmnt);
+ *dentry = dget(fs->pwd);
+ result = 0;
+ put_fs_struct(fs);
}
return result;
}
static int proc_root_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
{
+ struct fs_struct *fs;
int result = -ENOENT;
- if (task_lock(inode->u.proc_i.task)) {
- struct fs_struct *fs = inode->u.proc_i.task->fs;
- if (fs) {
- *mnt = mntget(fs->rootmnt);
- *dentry = dget(fs->root);
- result = 0;
- }
- task_unlock(inode->u.proc_i.task);
+ task_lock(inode->u.proc_i.task);
+ fs = inode->u.proc_i.task->fs;
+ if(fs)
+ atomic_inc(&fs->count);
+ task_unlock(inode->u.proc_i.task);
+ if (fs) {
+ *mnt = mntget(fs->rootmnt);
+ *dentry = dget(fs->root);
+ result = 0;
+ put_fs_struct(fs);
}
return result;
}
-/* task is locked and can't drop mm, so we are safe */
-
static int proc_pid_environ(struct task_struct *task, char * buffer)
{
- struct mm_struct *mm = task->mm;
+ struct mm_struct *mm;
int res = 0;
+ task_lock(task);
+ mm = task->mm;
+ if (mm)
+ atomic_inc(&mm->mm_users);
+ task_unlock(task);
if (mm) {
int len = mm->env_end - mm->env_start;
if (len > PAGE_SIZE)
len = PAGE_SIZE;
res = access_process_vm(task, mm->env_start, buffer, len, 0);
+ mmput(mm);
}
return res;
}
-/* task is locked and can't drop mm, so we are safe */
-
static int proc_pid_cmdline(struct task_struct *task, char * buffer)
{
- struct mm_struct *mm = task->mm;
+ struct mm_struct *mm;
int res = 0;
+ task_lock(task);
+ mm = task->mm;
+ if (mm)
+ atomic_inc(&mm->mm_users);
+ task_unlock(task);
if (mm) {
int len = mm->arg_end - mm->arg_start;
if (len > PAGE_SIZE)
len = PAGE_SIZE;
res = access_process_vm(task, mm->arg_start, buffer, len, 0);
+ mmput(mm);
}
return res;
}
@@ -174,7 +196,6 @@ static int standard_permission(struct inode *inode, int mask)
static int proc_permission(struct inode *inode, int mask)
{
struct dentry *de, *base, *root;
- struct super_block *our_sb, *sb, *below;
struct vfsmount *our_vfsmnt, *vfsmnt, *mnt;
if (standard_permission(inode, mask) != 0)
@@ -187,14 +208,12 @@ static int proc_permission(struct inode *inode, int mask)
de = root;
mnt = vfsmnt;
- our_sb = base->d_inode->i_sb;
- sb = de->d_inode->i_sb;
- while (sb != our_sb) {
- de = sb->s_root->d_covers;
- below = de->d_inode->i_sb;
- if (sb == below)
+
+ while (vfsmnt != our_vfsmnt) {
+ if (vfsmnt == vfsmnt->mnt_parent)
goto out;
- sb = below;
+ de = vfsmnt->mnt_mountpoint;
+ vfsmnt = vfsmnt->mnt_parent;
}
if (!is_subdir(de, base))
@@ -216,10 +235,7 @@ static ssize_t pid_maps_read(struct file * file, char * buf,
struct task_struct *task = inode->u.proc_i.task;
ssize_t res;
- if (!task_lock(task))
- return -EIO;
res = proc_pid_read_maps(task, file, buf, count, ppos);
- task_unlock(task);
return res;
}
@@ -243,15 +259,8 @@ static ssize_t proc_info_read(struct file * file, char * buf,
if (!(page = __get_free_page(GFP_KERNEL)))
return -ENOMEM;
- if (!task_lock(task)) {
- free_page(page);
- return -EIO;
- }
-
length = inode->u.proc_i.op.proc_read(task, (char*)page);
- task_unlock(task);
-
if (length < 0) {
free_page(page);
return length;
@@ -368,10 +377,12 @@ static int proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
{
struct inode *inode = dentry->d_inode;
int error;
+#ifdef NULL_VFSMNT
+ struct vfsmount *dummy = mntget(nd->mnt);
+#endif
/* We don't need a base pointer in the /proc filesystem */
- dput(nd->dentry);
- mntput(nd->mnt);
+ path_release(nd);
error = proc_permission(inode, MAY_EXEC);
if (error)
@@ -379,6 +390,9 @@ static int proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
error = inode->u.proc_i.op.proc_get_link(inode, &nd->dentry, &nd->mnt);
out:
+#ifdef NULL_VFSMNT
+ mntput(dummy);
+#endif
return error;
}
@@ -421,18 +435,19 @@ static int proc_pid_readlink(struct dentry * dentry, char * buffer, int buflen)
{
int error;
struct inode *inode = dentry->d_inode;
- struct vfsmount *mnt;
+ struct dentry *de;
+ struct vfsmount *mnt = NULL;
error = proc_permission(inode, MAY_EXEC);
if (error)
goto out;
- error = inode->u.proc_i.op.proc_get_link(inode, &dentry, &mnt);
+ error = inode->u.proc_i.op.proc_get_link(inode, &de, &mnt);
if (error)
goto out;
- error = do_proc_readlink(dentry, mnt, buffer, buflen);
- dput(dentry);
+ error = do_proc_readlink(de, mnt, buffer, buflen);
+ dput(de);
mntput(mnt);
out:
return error;
@@ -496,6 +511,7 @@ static int proc_readfd(struct file * filp, void * dirent, filldir_t filldir)
unsigned int fd, pid, ino;
int retval;
char buf[NUMBUF];
+ struct files_struct * files;
retval = 0;
pid = p->pid;
@@ -512,12 +528,19 @@ static int proc_readfd(struct file * filp, void * dirent, filldir_t filldir)
goto out;
filp->f_pos++;
default:
+ task_lock(p);
+ files = p->files;
+ if (files)
+ atomic_inc(&files->count);
+ task_unlock(p);
+ if (!files)
+ goto out;
for (fd = filp->f_pos-2;
- p->p_pptr && p->files && fd < p->files->max_fds;
+ fd < files->max_fds;
fd++, filp->f_pos++) {
unsigned int i,j;
- if (!fcheck_task(p, fd))
+ if (!fcheck_files(files, fd))
continue;
j = NUMBUF;
@@ -531,8 +554,8 @@ static int proc_readfd(struct file * filp, void * dirent, filldir_t filldir)
ino = fake_ino(pid, PROC_PID_FD_DIR + fd);
if (filldir(dirent, buf+j, NUMBUF-j, fd+2, ino) < 0)
break;
-
}
+ put_files_struct(files);
}
out:
return retval;
@@ -688,16 +711,20 @@ static struct dentry *proc_lookupfd(struct inode * dir, struct dentry * dentry)
inode = proc_pid_make_inode(dir->i_sb, task, PROC_PID_FD_DIR+fd);
if (!inode)
goto out;
- /* FIXME */
+ task_lock(task);
files = task->files;
- if (!files) /* can we ever get here if that's the case? */
+ if (files)
+ atomic_inc(&files->count);
+ task_unlock(task);
+ if (!files)
goto out_unlock;
read_lock(&files->file_lock);
- file = inode->u.proc_i.file = fcheck_task(task, fd);
+ file = inode->u.proc_i.file = fcheck_files(files, fd);
if (!file)
goto out_unlock2;
get_file(file);
read_unlock(&files->file_lock);
+ put_files_struct(files);
inode->i_op = &proc_pid_link_inode_operations;
inode->i_size = 64;
inode->i_mode = S_IFLNK;
@@ -711,6 +738,7 @@ static struct dentry *proc_lookupfd(struct inode * dir, struct dentry * dentry)
return NULL;
out_unlock2:
+ put_files_struct(files);
read_unlock(&files->file_lock);
out_unlock:
iput(inode);
generated by cgit v1.2.3 (git 2.25.1) at 2024-09-19 23:46:56 +0000