unsigned long totalpages = totalram_pages + total_swap_pages;
unsigned long points = 0;
- read_lock(&tasklist_lock);
- if (pid_alive(task))
- points = oom_badness(task, NULL, NULL, totalpages) *
- 1000 / totalpages;
- read_unlock(&tasklist_lock);
+ points = oom_badness(task, NULL, NULL, totalpages) *
+ 1000 / totalpages;
seq_printf(m, "%lu\n", points);
return 0;
char buffer[PROC_NUMBUF];
int oom_adj = OOM_ADJUST_MIN;
size_t len;
- unsigned long flags;
if (!task)
return -ESRCH;
- if (lock_task_sighand(task, &flags)) {
- if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
- oom_adj = OOM_ADJUST_MAX;
- else
- oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
- OOM_SCORE_ADJ_MAX;
- unlock_task_sighand(task, &flags);
- }
+ if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
+ oom_adj = OOM_ADJUST_MAX;
+ else
+ oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
+ OOM_SCORE_ADJ_MAX;
put_task_struct(task);
len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj);
return simple_read_from_buffer(buf, count, ppos, buffer, len);
}
+static int __set_oom_adj(struct file *file, int oom_adj, bool legacy)
+{
+ static DEFINE_MUTEX(oom_adj_mutex);
+ struct mm_struct *mm = NULL;
+ struct task_struct *task;
+ int err = 0;
+
+ task = get_proc_task(file_inode(file));
+ if (!task)
+ return -ESRCH;
+
+ mutex_lock(&oom_adj_mutex);
+ if (legacy) {
+ if (oom_adj < task->signal->oom_score_adj &&
+ !capable(CAP_SYS_RESOURCE)) {
+ err = -EACCES;
+ goto err_unlock;
+ }
+ /*
+ * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
+ * /proc/pid/oom_score_adj instead.
+ */
+ pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
+ current->comm, task_pid_nr(current), task_pid_nr(task),
+ task_pid_nr(task));
+ } else {
+ if ((short)oom_adj < task->signal->oom_score_adj_min &&
+ !capable(CAP_SYS_RESOURCE)) {
+ err = -EACCES;
+ goto err_unlock;
+ }
+ }
+
+ /*
+ * Make sure we will check other processes sharing the mm if this is
+ * not vfrok which wants its own oom_score_adj.
+ * pin the mm so it doesn't go away and get reused after task_unlock
+ */
+ if (!task->vfork_done) {
+ struct task_struct *p = find_lock_task_mm(task);
+
+ if (p) {
+ if (atomic_read(&p->mm->mm_users) > 1) {
+ mm = p->mm;
+ atomic_inc(&mm->mm_count);
+ }
+ task_unlock(p);
+ }
+ }
+
+ task->signal->oom_score_adj = oom_adj;
+ if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
+ task->signal->oom_score_adj_min = (short)oom_adj;
+ trace_oom_score_adj_update(task);
+
+ if (mm) {
+ struct task_struct *p;
+
+ rcu_read_lock();
+ for_each_process(p) {
+ if (same_thread_group(task, p))
+ continue;
+
+ /* do not touch kernel threads or the global init */
+ if (p->flags & PF_KTHREAD || is_global_init(p))
+ continue;
+
+ task_lock(p);
+ if (!p->vfork_done && process_shares_mm(p, mm)) {
+ pr_info("updating oom_score_adj for %d (%s) from %d to %d because it shares mm with %d (%s). Report if this is unexpected.\n",
+ task_pid_nr(p), p->comm,
+ p->signal->oom_score_adj, oom_adj,
+ task_pid_nr(task), task->comm);
+ p->signal->oom_score_adj = oom_adj;
+ if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
+ p->signal->oom_score_adj_min = (short)oom_adj;
+ }
+ task_unlock(p);
+ }
+ rcu_read_unlock();
+ mmdrop(mm);
+ }
+err_unlock:
+ mutex_unlock(&oom_adj_mutex);
+ put_task_struct(task);
+ return err;
+}
+
/*
* /proc/pid/oom_adj exists solely for backwards compatibility with previous
* kernels. The effective policy is defined by oom_score_adj, which has a
static ssize_t oom_adj_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
- struct task_struct *task;
char buffer[PROC_NUMBUF];
int oom_adj;
- unsigned long flags;
int err;
memset(buffer, 0, sizeof(buffer));
goto out;
}
- task = get_proc_task(file_inode(file));
- if (!task) {
- err = -ESRCH;
- goto out;
- }
-
- task_lock(task);
- if (!task->mm) {
- err = -EINVAL;
- goto err_task_lock;
- }
-
- if (!lock_task_sighand(task, &flags)) {
- err = -ESRCH;
- goto err_task_lock;
- }
-
/*
* Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
* value is always attainable.
else
oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE;
- if (oom_adj < task->signal->oom_score_adj &&
- !capable(CAP_SYS_RESOURCE)) {
- err = -EACCES;
- goto err_sighand;
- }
-
- /*
- * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
- * /proc/pid/oom_score_adj instead.
- */
- pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
- current->comm, task_pid_nr(current), task_pid_nr(task),
- task_pid_nr(task));
-
- task->signal->oom_score_adj = oom_adj;
- trace_oom_score_adj_update(task);
-err_sighand:
- unlock_task_sighand(task, &flags);
-err_task_lock:
- task_unlock(task);
- put_task_struct(task);
+ err = __set_oom_adj(file, oom_adj, true);
out:
return err < 0 ? err : count;
}
struct task_struct *task = get_proc_task(file_inode(file));
char buffer[PROC_NUMBUF];
short oom_score_adj = OOM_SCORE_ADJ_MIN;
- unsigned long flags;
size_t len;
if (!task)
return -ESRCH;
- if (lock_task_sighand(task, &flags)) {
- oom_score_adj = task->signal->oom_score_adj;
- unlock_task_sighand(task, &flags);
- }
+ oom_score_adj = task->signal->oom_score_adj;
put_task_struct(task);
len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj);
return simple_read_from_buffer(buf, count, ppos, buffer, len);
static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
- struct task_struct *task;
char buffer[PROC_NUMBUF];
- unsigned long flags;
int oom_score_adj;
int err;
goto out;
}
- task = get_proc_task(file_inode(file));
- if (!task) {
- err = -ESRCH;
- goto out;
- }
-
- task_lock(task);
- if (!task->mm) {
- err = -EINVAL;
- goto err_task_lock;
- }
-
- if (!lock_task_sighand(task, &flags)) {
- err = -ESRCH;
- goto err_task_lock;
- }
-
- if ((short)oom_score_adj < task->signal->oom_score_adj_min &&
- !capable(CAP_SYS_RESOURCE)) {
- err = -EACCES;
- goto err_sighand;
- }
-
- task->signal->oom_score_adj = (short)oom_score_adj;
- if (has_capability_noaudit(current, CAP_SYS_RESOURCE))
- task->signal->oom_score_adj_min = (short)oom_score_adj;
- trace_oom_score_adj_update(task);
-
-err_sighand:
- unlock_task_sighand(task, &flags);
-err_task_lock:
- task_unlock(task);
- put_task_struct(task);
+ err = __set_oom_adj(file, oom_score_adj, false);
out:
return err < 0 ? err : count;
}
child = d_hash_and_lookup(dir, &qname);
if (!child) {
- child = d_alloc(dir, &qname);
- if (!child)
- goto end_instantiate;
- if (instantiate(d_inode(dir), child, task, ptr) < 0) {
- dput(child);
+ DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
+ child = d_alloc_parallel(dir, &qname, &wq);
+ if (IS_ERR(child))
goto end_instantiate;
+ if (d_in_lookup(child)) {
+ int err = instantiate(d_inode(dir), child, task, ptr);
+ d_lookup_done(child);
+ if (err < 0) {
+ dput(child);
+ goto end_instantiate;
+ }
}
}
inode = d_inode(child);
static const struct file_operations proc_map_files_operations = {
.read = generic_read_dir,
- .iterate = proc_map_files_readdir,
- .llseek = default_llseek,
+ .iterate_shared = proc_map_files_readdir,
+ .llseek = generic_file_llseek,
};
#ifdef CONFIG_CHECKPOINT_RESTORE
static const struct file_operations proc_attr_dir_operations = {
.read = generic_read_dir,
- .iterate = proc_attr_dir_readdir,
- .llseek = default_llseek,
+ .iterate_shared = proc_attr_dir_readdir,
+ .llseek = generic_file_llseek,
};
static struct dentry *proc_attr_dir_lookup(struct inode *dir,
static const struct file_operations proc_tgid_base_operations = {
.read = generic_read_dir,
- .iterate = proc_tgid_base_readdir,
- .llseek = default_llseek,
+ .iterate_shared = proc_tgid_base_readdir,
+ .llseek = generic_file_llseek,
};
static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
return 0;
}
+/*
+ * proc_tid_comm_permission is a special permission function exclusively
+ * used for the node /proc/<pid>/task/<tid>/comm.
+ * It bypasses generic permission checks in the case where a task of the same
+ * task group attempts to access the node.
+ * The rationale behind this is that glibc and bionic access this node for
+ * cross thread naming (pthread_set/getname_np(!self)). However, if
+ * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0,
+ * which locks out the cross thread naming implementation.
+ * This function makes sure that the node is always accessible for members of
+ * same thread group.
+ */
+static int proc_tid_comm_permission(struct inode *inode, int mask)
+{
+ bool is_same_tgroup;
+ struct task_struct *task;
+
+ task = get_proc_task(inode);
+ if (!task)
+ return -ESRCH;
+ is_same_tgroup = same_thread_group(current, task);
+ put_task_struct(task);
+
+ if (likely(is_same_tgroup && !(mask & MAY_EXEC))) {
+ /* This file (/proc/<pid>/task/<tid>/comm) can always be
+ * read or written by the members of the corresponding
+ * thread group.
+ */
+ return 0;
+ }
+
+ return generic_permission(inode, mask);
+}
+
+static const struct inode_operations proc_tid_comm_inode_operations = {
+ .permission = proc_tid_comm_permission,
+};
+
/*
* Tasks
*/
#ifdef CONFIG_SCHED_DEBUG
REG("sched", S_IRUGO|S_IWUSR, proc_pid_sched_operations),
#endif
- REG("comm", S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
+ NOD("comm", S_IFREG|S_IRUGO|S_IWUSR,
+ &proc_tid_comm_inode_operations,
+ &proc_pid_set_comm_operations, {}),
#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
ONE("syscall", S_IRUSR, proc_pid_syscall),
#endif
static const struct file_operations proc_tid_base_operations = {
.read = generic_read_dir,
- .iterate = proc_tid_base_readdir,
- .llseek = default_llseek,
+ .iterate_shared = proc_tid_base_readdir,
+ .llseek = generic_file_llseek,
};
static const struct inode_operations proc_tid_base_inode_operations = {
static const struct file_operations proc_task_operations = {
.read = generic_read_dir,
- .iterate = proc_task_readdir,
- .llseek = default_llseek,
+ .iterate_shared = proc_task_readdir,
+ .llseek = generic_file_llseek,
};
git.samba.org / sfrench / cifs-2.6.git / blobdiff