aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorPavel Emelyanov <xemul@openvz.org>2007-10-18 23:40:18 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-19 11:53:40 -0700
commitbac0abd6174e427404dd197cdbefece31e97329b (patch)
tree68ed6bd8619552c921c9fb99e83cb04fcb235a39
parent19b9b9b54e5f115907efd56be2c3799775a46561 (diff)
downloadvexpress-lsk-bac0abd6174e427404dd197cdbefece31e97329b.tar.gz
Isolate some explicit usage of task->tgid
With pid namespaces this field is now dangerous to use explicitly, so hide it behind the helpers. Also the pid and pgrp fields o task_struct and signal_struct are to be deprecated. Unfortunately this patch cannot be sent right now as this leads to tons of warnings, so start isolating them, and deprecate later. Actually the p->tgid == pid has to be changed to has_group_leader_pid(), but Oleg pointed out that in case of posix cpu timers this is the same, and thread_group_leader() is more preferable. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--fs/exec.c4
-rw-r--r--fs/proc/base.c2
-rw-r--r--include/linux/sched.h6
-rw-r--r--kernel/posix-cpu-timers.c12
-rw-r--r--kernel/posix-timers.c4
-rw-r--r--kernel/ptrace.c2
-rw-r--r--kernel/signal.c2
-rw-r--r--mm/oom_kill.c2
8 files changed, 20 insertions, 14 deletions
diff --git a/fs/exec.c b/fs/exec.c
index 007d0d814bf..2c942e2d14e 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -841,8 +841,8 @@ static int de_thread(struct task_struct *tsk)
*/
tsk->start_time = leader->start_time;
- BUG_ON(leader->tgid != tsk->tgid);
- BUG_ON(tsk->pid == tsk->tgid);
+ BUG_ON(!same_thread_group(leader, tsk));
+ BUG_ON(has_group_leader_pid(tsk));
/*
* An exec() starts a new thread group with the
* TGID of the previous thread group. Rehash the
diff --git a/fs/proc/base.c b/fs/proc/base.c
index db7636041c1..991482811f1 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2553,7 +2553,7 @@ static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry
rcu_read_unlock();
if (!task)
goto out;
- if (leader->tgid != task->tgid)
+ if (!same_thread_group(leader, task))
goto out_drop_task;
result = proc_task_instantiate(dir, dentry, task, NULL);
diff --git a/include/linux/sched.h b/include/linux/sched.h
index f4d969e8561..eb2ae68804a 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1725,6 +1725,12 @@ static inline int has_group_leader_pid(struct task_struct *p)
return p->pid == p->tgid;
}
+static inline
+int same_thread_group(struct task_struct *p1, struct task_struct *p2)
+{
+ return p1->tgid == p2->tgid;
+}
+
static inline struct task_struct *next_thread(const struct task_struct *p)
{
return list_entry(rcu_dereference(p->thread_group.next),
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index b53c8fcd9d8..68c96376e84 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -21,8 +21,8 @@ static int check_clock(const clockid_t which_clock)
read_lock(&tasklist_lock);
p = find_task_by_pid(pid);
- if (!p || (CPUCLOCK_PERTHREAD(which_clock) ?
- p->tgid != current->tgid : p->tgid != pid)) {
+ if (!p || !(CPUCLOCK_PERTHREAD(which_clock) ?
+ same_thread_group(p, current) : thread_group_leader(p))) {
error = -EINVAL;
}
read_unlock(&tasklist_lock);
@@ -308,13 +308,13 @@ int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *tp)
p = find_task_by_pid(pid);
if (p) {
if (CPUCLOCK_PERTHREAD(which_clock)) {
- if (p->tgid == current->tgid) {
+ if (same_thread_group(p, current)) {
error = cpu_clock_sample(which_clock,
p, &rtn);
}
} else {
read_lock(&tasklist_lock);
- if (p->tgid == pid && p->signal) {
+ if (thread_group_leader(p) && p->signal) {
error =
cpu_clock_sample_group(which_clock,
p, &rtn);
@@ -355,7 +355,7 @@ int posix_cpu_timer_create(struct k_itimer *new_timer)
p = current;
} else {
p = find_task_by_pid(pid);
- if (p && p->tgid != current->tgid)
+ if (p && !same_thread_group(p, current))
p = NULL;
}
} else {
@@ -363,7 +363,7 @@ int posix_cpu_timer_create(struct k_itimer *new_timer)
p = current->group_leader;
} else {
p = find_task_by_pid(pid);
- if (p && p->tgid != pid)
+ if (p && !thread_group_leader(p))
p = NULL;
}
}
diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c
index d11f579d189..35b4bbfc78f 100644
--- a/kernel/posix-timers.c
+++ b/kernel/posix-timers.c
@@ -404,7 +404,7 @@ static struct task_struct * good_sigevent(sigevent_t * event)
if ((event->sigev_notify & SIGEV_THREAD_ID ) &&
(!(rtn = find_task_by_pid(event->sigev_notify_thread_id)) ||
- rtn->tgid != current->tgid ||
+ !same_thread_group(rtn, current) ||
(event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_SIGNAL))
return NULL;
@@ -608,7 +608,7 @@ static struct k_itimer * lock_timer(timer_t timer_id, unsigned long *flags)
spin_lock(&timr->it_lock);
if ((timr->it_id != timer_id) || !(timr->it_process) ||
- timr->it_process->tgid != current->tgid) {
+ !same_thread_group(timr->it_process, current)) {
spin_unlock(&timr->it_lock);
spin_unlock_irqrestore(&idr_lock, *flags);
timr = NULL;
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index b0ace60ce59..7c76f2ffaea 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -169,7 +169,7 @@ int ptrace_attach(struct task_struct *task)
retval = -EPERM;
if (task->pid <= 1)
goto out;
- if (task->tgid == current->tgid)
+ if (same_thread_group(task, current))
goto out;
repeat:
diff --git a/kernel/signal.c b/kernel/signal.c
index 783b33a0af0..08364e75bb5 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1150,7 +1150,7 @@ static int kill_something_info(int sig, struct siginfo *info, int pid)
read_lock(&tasklist_lock);
for_each_process(p) {
- if (p->pid > 1 && p->tgid != current->tgid) {
+ if (p->pid > 1 && !same_thread_group(p, current)) {
int err = group_send_sig_info(sig, info, p);
++count;
if (err != -EPERM)
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index a7cb4c43fd1..e3778f1215c 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -326,7 +326,7 @@ static int oom_kill_task(struct task_struct *p)
* to memory reserves though, otherwise we might deplete all memory.
*/
do_each_thread(g, q) {
- if (q->mm == mm && q->tgid != p->tgid)
+ if (q->mm == mm && !same_thread_group(q, p))
force_sig(SIGKILL, q);
} while_each_thread(g, q);