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-rw-r--r--fs/proc/base.c355
-rw-r--r--fs/proc/inode.c9
-rw-r--r--fs/proc/internal.h15
-rw-r--r--fs/proc/task_mmu.c72
4 files changed, 319 insertions, 132 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 20746e12440..489810abc72 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -307,12 +307,15 @@ static struct pid_entry tid_attr_stuff[] = {
static int proc_fd_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
{
- struct task_struct *task = proc_task(inode);
- struct files_struct *files;
+ struct task_struct *task = get_proc_task(inode);
+ struct files_struct *files = NULL;
struct file *file;
int fd = proc_fd(inode);
- files = get_files_struct(task);
+ if (task) {
+ files = get_files_struct(task);
+ put_task_struct(task);
+ }
if (files) {
/*
* We are not taking a ref to the file structure, so we must
@@ -344,10 +347,29 @@ static struct fs_struct *get_fs_struct(struct task_struct *task)
return fs;
}
+static int get_nr_threads(struct task_struct *tsk)
+{
+ /* Must be called with the rcu_read_lock held */
+ unsigned long flags;
+ int count = 0;
+
+ if (lock_task_sighand(tsk, &flags)) {
+ count = atomic_read(&tsk->signal->count);
+ unlock_task_sighand(tsk, &flags);
+ }
+ return count;
+}
+
static int proc_cwd_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
{
- struct fs_struct *fs = get_fs_struct(proc_task(inode));
+ struct task_struct *task = get_proc_task(inode);
+ struct fs_struct *fs = NULL;
int result = -ENOENT;
+
+ if (task) {
+ fs = get_fs_struct(task);
+ put_task_struct(task);
+ }
if (fs) {
read_lock(&fs->lock);
*mnt = mntget(fs->pwdmnt);
@@ -361,8 +383,14 @@ static int proc_cwd_link(struct inode *inode, struct dentry **dentry, struct vfs
static int proc_root_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
{
- struct fs_struct *fs = get_fs_struct(proc_task(inode));
+ struct task_struct *task = get_proc_task(inode);
+ struct fs_struct *fs = NULL;
int result = -ENOENT;
+
+ if (task) {
+ fs = get_fs_struct(task);
+ put_task_struct(task);
+ }
if (fs) {
read_lock(&fs->lock);
*mnt = mntget(fs->rootmnt);
@@ -550,16 +578,19 @@ struct proc_mounts {
static int mounts_open(struct inode *inode, struct file *file)
{
- struct task_struct *task = proc_task(inode);
- struct namespace *namespace;
+ struct task_struct *task = get_proc_task(inode);
+ struct namespace *namespace = NULL;
struct proc_mounts *p;
int ret = -EINVAL;
- task_lock(task);
- namespace = task->namespace;
- if (namespace)
- get_namespace(namespace);
- task_unlock(task);
+ if (task) {
+ task_lock(task);
+ namespace = task->namespace;
+ if (namespace)
+ get_namespace(namespace);
+ task_unlock(task);
+ put_task_struct(task);
+ }
if (namespace) {
ret = -ENOMEM;
@@ -616,17 +647,21 @@ static struct file_operations proc_mounts_operations = {
extern struct seq_operations mountstats_op;
static int mountstats_open(struct inode *inode, struct file *file)
{
- struct task_struct *task = proc_task(inode);
int ret = seq_open(file, &mountstats_op);
if (!ret) {
struct seq_file *m = file->private_data;
- struct namespace *namespace;
- task_lock(task);
- namespace = task->namespace;
- if (namespace)
- get_namespace(namespace);
- task_unlock(task);
+ struct namespace *namespace = NULL;
+ struct task_struct *task = get_proc_task(inode);
+
+ if (task) {
+ task_lock(task);
+ namespace = task->namespace;
+ if (namespace)
+ get_namespace(namespace);
+ task_unlock(task);
+ put_task_struct(task);
+ }
if (namespace)
m->private = namespace;
@@ -653,18 +688,27 @@ static ssize_t proc_info_read(struct file * file, char __user * buf,
struct inode * inode = file->f_dentry->d_inode;
unsigned long page;
ssize_t length;
- struct task_struct *task = proc_task(inode);
+ struct task_struct *task = get_proc_task(inode);
+
+ length = -ESRCH;
+ if (!task)
+ goto out_no_task;
if (count > PROC_BLOCK_SIZE)
count = PROC_BLOCK_SIZE;
+
+ length = -ENOMEM;
if (!(page = __get_free_page(GFP_KERNEL)))
- return -ENOMEM;
+ goto out;
length = PROC_I(inode)->op.proc_read(task, (char*)page);
if (length >= 0)
length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
free_page(page);
+out:
+ put_task_struct(task);
+out_no_task:
return length;
}
@@ -681,12 +725,15 @@ static int mem_open(struct inode* inode, struct file* file)
static ssize_t mem_read(struct file * file, char __user * buf,
size_t count, loff_t *ppos)
{
- struct task_struct *task = proc_task(file->f_dentry->d_inode);
+ struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
char *page;
unsigned long src = *ppos;
int ret = -ESRCH;
struct mm_struct *mm;
+ if (!task)
+ goto out_no_task;
+
if (!MAY_PTRACE(task) || !ptrace_may_attach(task))
goto out;
@@ -736,6 +783,8 @@ out_put:
out_free:
free_page((unsigned long) page);
out:
+ put_task_struct(task);
+out_no_task:
return ret;
}
@@ -748,15 +797,20 @@ static ssize_t mem_write(struct file * file, const char * buf,
{
int copied = 0;
char *page;
- struct task_struct *task = proc_task(file->f_dentry->d_inode);
+ struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
unsigned long dst = *ppos;
+ copied = -ESRCH;
+ if (!task)
+ goto out_no_task;
+
if (!MAY_PTRACE(task) || !ptrace_may_attach(task))
- return -ESRCH;
+ goto out;
+ copied = -ENOMEM;
page = (char *)__get_free_page(GFP_USER);
if (!page)
- return -ENOMEM;
+ goto out;
while (count > 0) {
int this_len, retval;
@@ -779,6 +833,9 @@ static ssize_t mem_write(struct file * file, const char * buf,
}
*ppos = dst;
free_page((unsigned long) page);
+out:
+ put_task_struct(task);
+out_no_task:
return copied;
}
#endif
@@ -809,12 +866,17 @@ static struct file_operations proc_mem_operations = {
static ssize_t oom_adjust_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
- struct task_struct *task = proc_task(file->f_dentry->d_inode);
+ struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
char buffer[PROC_NUMBUF];
size_t len;
- int oom_adjust = task->oomkilladj;
+ int oom_adjust;
loff_t __ppos = *ppos;
+ if (!task)
+ return -ESRCH;
+ oom_adjust = task->oomkilladj;
+ put_task_struct(task);
+
len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust);
if (__ppos >= len)
return 0;
@@ -829,7 +891,7 @@ static ssize_t oom_adjust_read(struct file *file, char __user *buf,
static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
- struct task_struct *task = proc_task(file->f_dentry->d_inode);
+ struct task_struct *task;
char buffer[PROC_NUMBUF], *end;
int oom_adjust;
@@ -845,7 +907,11 @@ static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
return -EINVAL;
if (*end == '\n')
end++;
+ task = get_proc_task(file->f_dentry->d_inode);
+ if (!task)
+ return -ESRCH;
task->oomkilladj = oom_adjust;
+ put_task_struct(task);
if (end - buffer == 0)
return -EIO;
return end - buffer;
@@ -862,12 +928,15 @@ static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
size_t count, loff_t *ppos)
{
struct inode * inode = file->f_dentry->d_inode;
- struct task_struct *task = proc_task(inode);
+ struct task_struct *task = get_proc_task(inode);
ssize_t length;
char tmpbuf[TMPBUFLEN];
+ if (!task)
+ return -ESRCH;
length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
audit_get_loginuid(task->audit_context));
+ put_task_struct(task);
return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
}
@@ -877,13 +946,12 @@ static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
struct inode * inode = file->f_dentry->d_inode;
char *page, *tmp;
ssize_t length;
- struct task_struct *task = proc_task(inode);
uid_t loginuid;
if (!capable(CAP_AUDIT_CONTROL))
return -EPERM;
- if (current != task)
+ if (current != proc_tref(inode)->task)
return -EPERM;
if (count >= PAGE_SIZE)
@@ -907,7 +975,7 @@ static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
goto out_free_page;
}
- length = audit_set_loginuid(task, loginuid);
+ length = audit_set_loginuid(current, loginuid);
if (likely(length == 0))
length = count;
@@ -926,13 +994,16 @@ static struct file_operations proc_loginuid_operations = {
static ssize_t seccomp_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
- struct task_struct *tsk = proc_task(file->f_dentry->d_inode);
+ struct task_struct *tsk = get_proc_task(file->f_dentry->d_inode);
char __buf[20];
loff_t __ppos = *ppos;
size_t len;
+ if (!tsk)
+ return -ESRCH;
/* no need to print the trailing zero, so use only len */
len = sprintf(__buf, "%u\n", tsk->seccomp.mode);
+ put_task_struct(tsk);
if (__ppos >= len)
return 0;
if (count > len - __ppos)
@@ -946,29 +1017,43 @@ static ssize_t seccomp_read(struct file *file, char __user *buf,
static ssize_t seccomp_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
- struct task_struct *tsk = proc_task(file->f_dentry->d_inode);
+ struct task_struct *tsk = get_proc_task(file->f_dentry->d_inode);
char __buf[20], *end;
unsigned int seccomp_mode;
+ ssize_t result;
+
+ result = -ESRCH;
+ if (!tsk)
+ goto out_no_task;
/* can set it only once to be even more secure */
+ result = -EPERM;
if (unlikely(tsk->seccomp.mode))
- return -EPERM;
+ goto out;
+ result = -EFAULT;
memset(__buf, 0, sizeof(__buf));
count = min(count, sizeof(__buf) - 1);
if (copy_from_user(__buf, buf, count))
- return -EFAULT;
+ goto out;
+
seccomp_mode = simple_strtoul(__buf, &end, 0);
if (*end == '\n')
end++;
+ result = -EINVAL;
if (seccomp_mode && seccomp_mode <= NR_SECCOMP_MODES) {
tsk->seccomp.mode = seccomp_mode;
set_tsk_thread_flag(tsk, TIF_SECCOMP);
} else
- return -EINVAL;
+ goto out;
+ result = -EIO;
if (unlikely(!(end - __buf)))
- return -EIO;
- return end - __buf;
+ goto out;
+ result = end - __buf;
+out:
+ put_task_struct(tsk);
+out_no_task:
+ return result;
}
static struct file_operations proc_seccomp_operations = {
@@ -995,7 +1080,7 @@ static int proc_check_dentry_visible(struct inode *inode,
/* See if the the two tasks share a commone set of
* file descriptors. If so everything is visible.
*/
- task = proc_task(inode);
+ task = get_proc_task(inode);
if (!task)
goto out;
files = get_files_struct(current);
@@ -1006,6 +1091,7 @@ static int proc_check_dentry_visible(struct inode *inode,
put_files_struct(task_files);
if (files)
put_files_struct(files);
+ put_task_struct(task);
if (!error)
goto out;
@@ -1106,7 +1192,7 @@ static int proc_readfd(struct file * filp, void * dirent, filldir_t filldir)
{
struct dentry *dentry = filp->f_dentry;
struct inode *inode = dentry->d_inode;
- struct task_struct *p = proc_task(inode);
+ struct task_struct *p = get_proc_task(inode);
unsigned int fd, tid, ino;
int retval;
char buf[PROC_NUMBUF];
@@ -1114,8 +1200,8 @@ static int proc_readfd(struct file * filp, void * dirent, filldir_t filldir)
struct fdtable *fdt;
retval = -ENOENT;
- if (!pid_alive(p))
- goto out;
+ if (!p)
+ goto out_no_task;
retval = 0;
tid = p->pid;
@@ -1164,6 +1250,8 @@ static int proc_readfd(struct file * filp, void * dirent, filldir_t filldir)
put_files_struct(files);
}
out:
+ put_task_struct(p);
+out_no_task:
return retval;
}
@@ -1175,16 +1263,18 @@ static int proc_pident_readdir(struct file *filp,
int pid;
struct dentry *dentry = filp->f_dentry;
struct inode *inode = dentry->d_inode;
+ struct task_struct *task = get_proc_task(inode);
struct pid_entry *p;
ino_t ino;
int ret;
ret = -ENOENT;
- if (!pid_alive(proc_task(inode)))
+ if (!task)
goto out;
ret = 0;
- pid = proc_task(inode)->pid;
+ pid = task->pid;
+ put_task_struct(task);
i = filp->f_pos;
switch (i) {
case 0:
@@ -1270,14 +1360,13 @@ static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_st
inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
inode->i_ino = fake_ino(task->pid, ino);
- if (!pid_alive(task))
- goto out_unlock;
-
/*
* grab the reference to task.
*/
- get_task_struct(task);
- ei->task = task;
+ ei->tref = tref_get_by_task(task);
+ if (!tref_task(ei->tref))
+ goto out_unlock;
+
inode->i_uid = 0;
inode->i_gid = 0;
if (task_dumpable(task)) {
@@ -1303,13 +1392,21 @@ out_unlock:
*
* Rewrite the inode's ownerships here because the owning task may have
* performed a setuid(), etc.
+ *
+ * Before the /proc/pid/status file was created the only way to read
+ * the effective uid of a /process was to stat /proc/pid. Reading
+ * /proc/pid/status is slow enough that procps and other packages
+ * kept stating /proc/pid. To keep the rules in /proc simple I have
+ * made this apply to all per process world readable and executable
+ * directories.
*/
static int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
{
struct inode *inode = dentry->d_inode;
- struct task_struct *task = proc_task(inode);
- if (pid_alive(task)) {
- if (task_dumpable(task)) {
+ struct task_struct *task = get_proc_task(inode);
+ if (task) {
+ if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
+ task_dumpable(task)) {
inode->i_uid = task->euid;
inode->i_gid = task->egid;
} else {
@@ -1317,37 +1414,63 @@ static int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
inode->i_gid = 0;
}
security_task_to_inode(task, inode);
+ put_task_struct(task);
return 1;
}
d_drop(dentry);
return 0;
}
+static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
+{
+ struct inode *inode = dentry->d_inode;
+ struct task_struct *task;
+ generic_fillattr(inode, stat);
+
+ rcu_read_lock();
+ stat->uid = 0;
+ stat->gid = 0;
+ task = pid_task(proc_pid(inode), PIDTYPE_PID);
+ if (task) {
+ if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
+ task_dumpable(task)) {
+ stat->uid = task->euid;
+ stat->gid = task->egid;
+ }
+ }
+ rcu_read_unlock();
+ return 0;
+}
+
static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
{
struct inode *inode = dentry->d_inode;
- struct task_struct *task = proc_task(inode);
+ struct task_struct *task = get_proc_task(inode);
int fd = proc_fd(inode);
struct files_struct *files;
- files = get_files_struct(task);
- if (files) {
- rcu_read_lock();
- if (fcheck_files(files, fd)) {
+ if (task) {
+ files = get_files_struct(task);
+ if (files) {
+ rcu_read_lock();
+ if (fcheck_files(files, fd)) {
+ rcu_read_unlock();
+ put_files_struct(files);
+ if (task_dumpable(task)) {
+ inode->i_uid = task->euid;
+ inode->i_gid = task->egid;
+ } else {
+ inode->i_uid = 0;
+ inode->i_gid = 0;
+ }
+ security_task_to_inode(task, inode);
+ put_task_struct(task);
+ return 1;
+ }
rcu_read_unlock();
put_files_struct(files);
- if (task_dumpable(task)) {
- inode->i_uid = task->euid;
- inode->i_gid = task->egid;
- } else {
- inode->i_uid = 0;
- inode->i_gid = 0;
- }
- security_task_to_inode(task, inode);
- return 1;
}
- rcu_read_unlock();
- put_files_struct(files);
+ put_task_struct(task);
}
d_drop(dentry);
return 0;
@@ -1359,7 +1482,7 @@ static int pid_delete_dentry(struct dentry * dentry)
* If so, then don't put the dentry on the lru list,
* kill it immediately.
*/
- return !pid_alive(proc_task(dentry->d_inode));
+ return !proc_tref(dentry->d_inode)->task;
}
static struct dentry_operations tid_fd_dentry_operations =
@@ -1401,7 +1524,7 @@ out:
/* SMP-safe */
static struct dentry *proc_lookupfd(struct inode * dir, struct dentry * dentry, struct nameidata *nd)
{
- struct task_struct *task = proc_task(dir);
+ struct task_struct *task = get_proc_task(dir);
unsigned fd = name_to_int(dentry);
struct dentry *result = ERR_PTR(-ENOENT);
struct file * file;
@@ -1409,10 +1532,10 @@ static struct dentry *proc_lookupfd(struct inode * dir, struct dentry * dentry,
struct inode *inode;
struct proc_inode *ei;
+ if (!task)
+ goto out_no_task;
if (fd == ~0U)
goto out;
- if (!pid_alive(task))
- goto out;
inode = proc_pid_make_inode(dir->i_sb, task, PROC_TID_FD_DIR+fd);
if (!inode)
@@ -1447,6 +1570,8 @@ static struct dentry *proc_lookupfd(struct inode * dir, struct dentry * dentry,
if (tid_fd_revalidate(dentry, NULL))
result = NULL;
out:
+ put_task_struct(task);
+out_no_task:
return result;
out_unlock2:
@@ -1490,12 +1615,17 @@ static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
struct inode * inode = file->f_dentry->d_inode;
unsigned long page;
ssize_t length;
- struct task_struct *task = proc_task(inode);
+ struct task_struct *task = get_proc_task(inode);
+
+ length = -ESRCH;
+ if (!task)
+ goto out_no_task;
if (count > PAGE_SIZE)
count = PAGE_SIZE;
+ length = -ENOMEM;
if (!(page = __get_free_page(GFP_KERNEL)))
- return -ENOMEM;
+ goto out;
length = security_getprocattr(task,
(char*)file->f_dentry->d_name.name,
@@ -1503,6 +1633,9 @@ static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
if (length >= 0)
length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
free_page(page);
+out:
+ put_task_struct(task);
+out_no_task:
return length;
}
@@ -1512,26 +1645,36 @@ static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
struct inode * inode = file->f_dentry->d_inode;
char *page;
ssize_t length;
- struct task_struct *task = proc_task(inode);
+ struct task_struct *task = get_proc_task(inode);
+ length = -ESRCH;
+ if (!task)
+ goto out_no_task;
if (count > PAGE_SIZE)
count = PAGE_SIZE;
- if (*ppos != 0) {
- /* No partial writes. */
- return -EINVAL;
- }
+
+ /* No partial writes. */
+ length = -EINVAL;
+ if (*ppos != 0)
+ goto out;
+
+ length = -ENOMEM;
page = (char*)__get_free_page(GFP_USER);
if (!page)
- return -ENOMEM;
+ goto out;
+
length = -EFAULT;
if (copy_from_user(page, buf, count))
- goto out;
+ goto out_free;
length = security_setprocattr(task,
(char*)file->f_dentry->d_name.name,
(void*)page, count);
-out:
+out_free:
free_page((unsigned long) page);
+out:
+ put_task_struct(task);
+out_no_task:
return length;
}
@@ -1553,15 +1696,15 @@ static struct dentry *proc_pident_lookup(struct inode *dir,
{
struct inode *inode;
struct dentry *error;
- struct task_struct *task = proc_task(dir);
+ struct task_struct *task = get_proc_task(dir);
struct pid_entry *p;
struct proc_inode *ei;
error = ERR_PTR(-ENOENT);
inode = NULL;
- if (!pid_alive(task))
- goto out;
+ if (!task)
+ goto out_no_task;
for (p = ents; p->name; p++) {
if (p->len != dentry->d_name.len)
@@ -1748,6 +1891,8 @@ static struct dentry *proc_pident_lookup(struct inode *dir,
if (pid_revalidate(dentry, NULL))
error = NULL;
out:
+ put_task_struct(task);
+out_no_task:
return error;
}
@@ -1771,10 +1916,12 @@ static struct file_operations proc_tid_base_operations = {
static struct inode_operations proc_tgid_base_inode_operations = {
.lookup = proc_tgid_base_lookup,
+ .getattr = pid_getattr,
};
static struct inode_operations proc_tid_base_inode_operations = {
.lookup = proc_tid_base_lookup,
+ .getattr = pid_getattr,
};
#ifdef CONFIG_SECURITY
@@ -1816,10 +1963,12 @@ static struct dentry *proc_tid_attr_lookup(struct inode *dir,
static struct inode_operations proc_tgid_attr_inode_operations = {
.lookup = proc_tgid_attr_lookup,
+ .getattr = pid_getattr,
};
static struct inode_operations proc_tid_attr_inode_operations = {
.lookup = proc_tid_attr_lookup,
+ .getattr = pid_getattr,
};
#endif
@@ -1981,10 +2130,13 @@ static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry
{
struct dentry *result = ERR_PTR(-ENOENT);
struct task_struct *task;
- struct task_struct *leader = proc_task(dir);
+ struct task_struct *leader = get_proc_task(dir);
struct inode *inode;
unsigned tid;
+ if (!leader)
+ goto out_no_task;
+
tid = name_to_int(dentry);
if (tid == ~0U)
goto out;
@@ -2024,6 +2176,8 @@ static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry
out_drop_task:
put_task_struct(task);
out:
+ put_task_struct(leader);
+out_no_task:
return result;
}
@@ -2163,12 +2317,7 @@ static struct task_struct *first_tid(struct task_struct *leader, int tid, int nr
/* If nr exceeds the number of threads there is nothing todo */
if (nr) {
- int threads = 0;
- task_lock(leader);
- if (leader->signal)
- threads = atomic_read(&leader->signal->count);
- task_unlock(leader);
- if (nr >= threads)
+ if (nr >= get_nr_threads(leader))
goto done;
}
@@ -2218,15 +2367,15 @@ static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldi
char buf[PROC_NUMBUF];
struct dentry *dentry = filp->f_dentry;
struct inode *inode = dentry->d_inode;
- struct task_struct *leader = proc_task(inode);
+ struct task_struct *leader = get_proc_task(inode);
struct task_struct *task;
int retval = -ENOENT;
ino_t ino;
int tid;
unsigned long pos = filp->f_pos; /* avoiding "long long" filp->f_pos */
- if (!pid_alive(leader))
- goto out;
+ if (!leader)
+ goto out_no_task;
retval = 0;
switch (pos) {
@@ -2266,20 +2415,22 @@ static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldi
}
out:
filp->f_pos = pos;
+ put_task_struct(leader);
+out_no_task:
return retval;
}
static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
{
struct inode *inode = dentry->d_inode;
- struct task_struct *p = proc_task(inode);
+ struct task_struct *p = get_proc_task(inode);
generic_fillattr(inode, stat);
- if (pid_alive(p)) {
- task_lock(p);
- if (p->signal)
- stat->nlink += atomic_read(&p->signal->count);
- task_unlock(p);
+ if (p) {
+ rcu_read_lock();
+ stat->nlink += get_nr_threads(p);
+ rcu_read_unlock();
+ put_task_struct(p);
}
return 0;
diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index fbc94df138a..31e0475c6cb 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -58,14 +58,11 @@ static void de_put(struct proc_dir_entry *de)
static void proc_delete_inode(struct inode *inode)
{
struct proc_dir_entry *de;
- struct task_struct *tsk;
truncate_inode_pages(&inode->i_data, 0);
- /* Let go of any associated process */
- tsk = PROC_I(inode)->task;
- if (tsk)
- put_task_struct(tsk);
+ /* Stop tracking associated processes */
+ tref_put(PROC_I(inode)->tref);
/* Let go of any associated proc directory entry */
de = PROC_I(inode)->pde;
@@ -94,7 +91,7 @@ static struct inode *proc_alloc_inode(struct super_block *sb)
ei = (struct proc_inode *)kmem_cache_alloc(proc_inode_cachep, SLAB_KERNEL);
if (!ei)
return NULL;
- ei->task = NULL;
+ ei->tref = NULL;
ei->fd = 0;
ei->op.proc_get_link = NULL;
ei->pde = NULL;
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index 548e7447ea4..37f1648adc2 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -10,6 +10,7 @@
*/
#include <linux/proc_fs.h>
+#include <linux/task_ref.h>
struct vmalloc_info {
unsigned long used;
@@ -41,13 +42,23 @@ extern struct file_operations proc_maps_operations;
extern struct file_operations proc_numa_maps_operations;
extern struct file_operations proc_smaps_operations;
+extern struct file_operations proc_maps_operations;
+extern struct file_operations proc_numa_maps_operations;
+extern struct file_operations proc_smaps_operations;
+
+
void free_proc_entry(struct proc_dir_entry *de);
int proc_init_inodecache(void);
-static inline struct task_struct *proc_task(struct inode *inode)
+static inline struct task_ref *proc_tref(struct inode *inode)
+{
+ return PROC_I(inode)->tref;
+}
+
+static inline struct task_struct *get_proc_task(struct inode *inode)
{
- return PROC_I(inode)->task;
+ return get_tref_task(proc_tref(inode));
}
static inline int proc_fd(struct inode *inode)
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 4187b4e9cdb..abf3208c3f6 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -75,9 +75,13 @@ int proc_exe_link(struct inode *inode, struct dentry **dentry, struct vfsmount *
{
struct vm_area_struct * vma;
int result = -ENOENT;
- struct task_struct *task = proc_task(inode);
- struct mm_struct * mm = get_task_mm(task);
+ struct task_struct *task = get_proc_task(inode);
+ struct mm_struct * mm = NULL;
+ if (task) {
+ mm = get_task_mm(task);
+ put_task_struct(task);
+ }
if (!mm)
goto out;
down_read(&mm->mmap_sem);
@@ -120,7 +124,8 @@ struct mem_size_stats
static int show_map_internal(struct seq_file *m, void *v, struct mem_size_stats *mss)
{
- struct task_struct *task = m->private;
+ struct proc_maps_private *priv = m->private;
+ struct task_struct *task = priv->task;
struct vm_area_struct *vma = v;
struct mm_struct *mm = vma->vm_mm;
struct file *file = vma->vm_file;
@@ -295,12 +300,16 @@ static int show_smap(struct seq_file *m, void *v)
static void *m_start(struct seq_file *m, loff_t *pos)
{
- struct task_struct *task = m->private;
+ struct proc_maps_private *priv = m->private;
unsigned long last_addr = m->version;
struct mm_struct *mm;
- struct vm_area_struct *vma, *tail_vma;
+ struct vm_area_struct *vma, *tail_vma = NULL;
loff_t l = *pos;
+ /* Clear the per syscall fields in priv */
+ priv->task = NULL;
+ priv->tail_vma = NULL;
+
/*
* We remember last_addr rather than next_addr to hit with
* mmap_cache most of the time. We have zero last_addr at
@@ -311,11 +320,15 @@ static void *m_start(struct seq_file *m, loff_t *pos)
if (last_addr == -1UL)
return NULL;
- mm = get_task_mm(task);
+ priv->task = get_tref_task(priv->tref);
+ if (!priv->task)
+ return NULL;
+
+ mm = get_task_mm(priv->task);
if (!mm)
return NULL;
- tail_vma = get_gate_vma(task);
+ priv->tail_vma = tail_vma = get_gate_vma(priv->task);
down_read(&mm->mmap_sem);
/* Start with last addr hint */
@@ -350,11 +363,9 @@ out:
return tail_vma;
}
-static void m_stop(struct seq_file *m, void *v)
+static void vma_stop(struct proc_maps_private *priv, struct vm_area_struct *vma)
{
- struct task_struct *task = m->private;
- struct vm_area_struct *vma = v;
- if (vma && vma != get_gate_vma(task)) {
+ if (vma && vma != priv->tail_vma) {
struct mm_struct *mm = vma->vm_mm;
up_read(&mm->mmap_sem);
mmput(mm);
@@ -363,17 +374,27 @@ static void m_stop(struct seq_file *m, void *v)
static void *m_next(struct seq_file *m, void *v, loff_t *pos)
{
- struct task_struct *task = m->private;
+ struct proc_maps_private *priv = m->private;
struct vm_area_struct *vma = v;
- struct vm_area_struct *tail_vma = get_gate_vma(task);
+ struct vm_area_struct *tail_vma = priv->tail_vma;
(*pos)++;
if (vma && (vma != tail_vma) && vma->vm_next)
return vma->vm_next;
- m_stop(m, v);
+ vma_stop(priv, vma);
return (vma != tail_vma)? tail_vma: NULL;
}
+static void m_stop(struct seq_file *m, void *v)
+{
+ struct proc_maps_private *priv = m->private;
+ struct vm_area_struct *vma = v;
+
+ vma_stop(priv, vma);
+ if (priv->task)
+ put_task_struct(priv->task);
+}
+
static struct seq_operations proc_pid_maps_op = {
.start = m_start,
.next = m_next,
@@ -391,11 +412,18 @@ static struct seq_operations proc_pid_smaps_op = {
static int do_maps_open(struct inode *inode, struct file *file,
struct seq_operations *ops)
{
- struct task_struct *task = proc_task(inode);
- int ret = seq_open(file, ops);
- if (!ret) {
- struct seq_file *m = file->private_data;
- m->private = task;
+ struct proc_maps_private *priv;
+ int ret = -ENOMEM;
+ priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+ if (priv) {
+ priv->tref = proc_tref(inode);
+ ret = seq_open(file, ops);
+ if (!ret) {
+ struct seq_file *m = file->private_data;
+ m->private = priv;
+ } else {
+ kfree(priv);
+ }
}
return ret;
}
@@ -409,7 +437,7 @@ struct file_operations proc_maps_operations = {
.open = maps_open,
.read = seq_read,
.llseek = seq_lseek,
- .release = seq_release,
+ .release = seq_release_private,
};
#ifdef CONFIG_NUMA
@@ -431,7 +459,7 @@ struct file_operations proc_numa_maps_operations = {
.open = numa_maps_open,
.read = seq_read,
.llseek = seq_lseek,
- .release = seq_release,
+ .release = seq_release_private,
};
#endif
@@ -444,5 +472,5 @@ struct file_operations proc_smaps_operations = {
.open = smaps_open,
.read = seq_read,
.llseek = seq_lseek,
- .release = seq_release,
+ .release = seq_release_private,
};
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-20 08:12:32 +0000