2006-01-30 09:49:54

by Oleg Nesterov

Subject: [PATCH 3/3] pidhash: temporal debug checks

This is only for testing in -mm tree.

Ensure that we really do not use pid == 0.

Signed-off-by: Oleg Nesterov <[email protected]>

--- RC-1/kernel/pid.c~DBG 2006-01-30 14:21:15.000000000 +0300
+++ RC-1/kernel/pid.c 2006-01-30 16:37:29.000000000 +0300
@@ -138,6 +138,7 @@ struct pid * fastcall find_pid(enum pid_

hlist_for_each_entry_rcu(pid, elem,
&pid_hash[type][pid_hashfn(nr)], pid_chain) {
+ WARN_ON(!pid->nr); /* to be removed soon */
if (pid->nr == nr)
return pid;
}
@@ -148,6 +149,9 @@ int fastcall attach_pid(task_t *task, en
{
struct pid *pid, *task_pid;

+ WARN_ON(!task->pid); /* to be removed soon */
+ WARN_ON(!nr); /* to be removed soon */
+
task_pid = &task->pids[type];
pid = find_pid(type, nr);
task_pid->nr = nr;
@@ -168,9 +172,11 @@ static fastcall int __detach_pid(task_t
struct pid *pid, *pid_next;
int nr = 0;

+ WARN_ON(!task->pid); /* to be removed soon */
+
pid = &task->pids[type];
if (!hlist_unhashed(&pid->pid_chain)) {
-
+ WARN_ON(!pid->nr); /* to be removed soon */
if (list_empty(&pid->pid_list)) {
nr = pid->nr;
hlist_del_rcu(&pid->pid_chain);
--- RC-1/kernel/fork.c~DBG 2006-01-30 14:17:58.000000000 +0300
+++ RC-1/kernel/fork.c 2006-01-30 15:43:40.000000000 +0300
@@ -1210,6 +1210,7 @@ task_t * __devinit fork_idle(int cpu)
task = copy_process(CLONE_VM, 0, idle_regs(&regs), 0, NULL, NULL, 0);
if (!task)
return ERR_PTR(-ENOMEM);
+ WARN_ON(task->proc_dentry); /* to be removed soon */
init_idle(task, cpu);

return task;

2006-01-30 13:16:53

by Oleg Nesterov

Subject: Re: [PATCH 3/3] pidhash: temporal debug checks

(Rediff after fixing a bug in [PATCH 1/3])

[PATCH 3/3] pidhash: temporal debug checks

This is for testing in -mm tree only. Ensure that we really do
not use pid == 0.

Signed-off-by: Oleg Nesterov <[email protected]>

--- RC-1/kernel/pid.c~DBG 2006-01-30 14:21:15.000000000 +0300
+++ RC-1/kernel/pid.c 2006-01-30 20:06:35.000000000 +0300
@@ -138,6 +138,7 @@ struct pid * fastcall find_pid(enum pid_

hlist_for_each_entry_rcu(pid, elem,
&pid_hash[type][pid_hashfn(nr)], pid_chain) {
+ WARN_ON(!pid->nr); /* to be removed soon */
if (pid->nr == nr)
return pid;
}
@@ -148,6 +149,9 @@ int fastcall attach_pid(task_t *task, en
{
struct pid *pid, *task_pid;

+ WARN_ON(!task->pid); /* to be removed soon */
+ WARN_ON(!nr); /* to be removed soon */
+
task_pid = &task->pids[type];
pid = find_pid(type, nr);
task_pid->nr = nr;
@@ -168,9 +172,11 @@ static fastcall int __detach_pid(task_t
struct pid *pid, *pid_next;
int nr = 0;

+ WARN_ON(!task->pid); /* to be removed soon */
+
pid = &task->pids[type];
if (!hlist_unhashed(&pid->pid_chain)) {
-
+ WARN_ON(!pid->nr); /* to be removed soon */
if (list_empty(&pid->pid_list)) {
nr = pid->nr;
hlist_del_rcu(&pid->pid_chain);
--- RC-1/kernel/fork.c~DBG 2006-01-30 19:52:59.000000000 +0300
+++ RC-1/kernel/fork.c 2006-01-30 20:06:22.000000000 +0300
@@ -1211,6 +1211,7 @@ task_t * __devinit fork_idle(int cpu)
if (!task)
return ERR_PTR(-ENOMEM);

+ WARN_ON(task->proc_dentry); /* to be removed soon */
REMOVE_LINKS(task);
init_idle(task, cpu);