| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <20070903210343.GQ14130@parisc-linux.org>
Date: Mon, 3 Sep 2007 15:03:43 -0600
From: Matthew Wilcox <matthew@....cx>
To: akpm@...l.org, torvalds@...l.org
Cc: linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/5] Use macros instead of TASK_ flags
On Sat, Sep 01, 2007 at 10:46:51PM -0400, Matthew Wilcox wrote:
> Abstracting away direct uses of TASK_ flags allows us to change the
> definitions of the task flags more easily.
>
> Also restructure do_wait() a little
>
> Signed-off-by: Matthew Wilcox <matthew@....cx>
> ---
> arch/ia64/kernel/perfmon.c | 4 +-
> fs/proc/array.c | 9 +---
> fs/proc/base.c | 2 +-
> include/linux/sched.h | 15 +++++++
> include/linux/wait.h | 11 +++--
> kernel/exit.c | 90 +++++++++++++++++++------------------------
> kernel/power/process.c | 7 +--
> kernel/ptrace.c | 8 ++--
> kernel/sched.c | 15 +++----
> kernel/signal.c | 6 +-
> kernel/wait.c | 2 +-
> 11 files changed, 83 insertions(+), 86 deletions(-)
Here's a replacement patch 2/5, including fixes for the problems spotted
by Daniel and myself. A machine running a kernel including these patches
has been up for more than 24 hours.
commit 10287ac5d615a2ccca6611426572259ebc69dc92
Author: Matthew Wilcox <matthew@....cx>
Date: Sat Sep 1 09:31:22 2007 -0400
Use macros instead of TASK_ flags
Abstracting away direct uses of TASK_ flags allows us to change the
definitions of the task flags more easily.
Also restructure do_wait() a little
Signed-off-by: Matthew Wilcox <matthew@....cx>
diff --git a/arch/ia64/kernel/perfmon.c b/arch/ia64/kernel/perfmon.c
index 14b8e5a..3690c46 100644
--- a/arch/ia64/kernel/perfmon.c
+++ b/arch/ia64/kernel/perfmon.c
@@ -2637,7 +2637,7 @@ pfm_task_incompatible(pfm_context_t *ctx, struct task_struct *task)
*/
if (task == current) return 0;
- if ((task->state != TASK_STOPPED) && (task->state != TASK_TRACED)) {
+ if (!is_task_stopped_or_traced(task)) {
DPRINT(("cannot attach to non-stopped task [%d] state=%ld\n", task->pid, task->state));
return -EBUSY;
}
@@ -4797,7 +4797,7 @@ recheck:
* the task must be stopped.
*/
if (PFM_CMD_STOPPED(cmd)) {
- if ((task->state != TASK_STOPPED) && (task->state != TASK_TRACED)) {
+ if (!is_task_stopped_or_traced(task)) {
DPRINT(("[%d] task not in stopped state\n", task->pid));
return -EBUSY;
}
diff --git a/fs/proc/array.c b/fs/proc/array.c
index ee4814d..6a3c876 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -140,13 +140,8 @@ static const char *task_state_array[] = {
static inline const char *get_task_state(struct task_struct *tsk)
{
- unsigned int state = (tsk->state & (TASK_RUNNING |
- TASK_INTERRUPTIBLE |
- TASK_UNINTERRUPTIBLE |
- TASK_STOPPED |
- TASK_TRACED)) |
- (tsk->exit_state & (EXIT_ZOMBIE |
- EXIT_DEAD));
+ unsigned int state = (tsk->state & TASK_REPORT) |
+ (tsk->exit_state & (EXIT_ZOMBIE | EXIT_DEAD));
const char **p = &task_state_array[0];
while (state) {
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 19489b0..3155ef1 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -196,7 +196,7 @@ static int proc_root_link(struct inode *inode, struct dentry **dentry, struct vf
(task == current || \
(task->parent == current && \
(task->ptrace & PT_PTRACED) && \
- (task->state == TASK_STOPPED || task->state == TASK_TRACED) && \
+ (is_task_stopped_or_traced(task)) && \
security_ptrace(current,task) == 0))
static int proc_pid_environ(struct task_struct *task, char * buffer)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index f4e324e..ea509e9 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -176,6 +176,21 @@ print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
#define TASK_NONINTERACTIVE 64
#define TASK_DEAD 128
+/* Convenience macros for the sake of wake_up */
+#define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
+#define TASK_ALL (TASK_NORMAL | TASK_STOPPED | TASK_TRACED)
+
+/* get_task_state() */
+#define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \
+ TASK_UNINTERRUPTIBLE | TASK_STOPPED | \
+ TASK_TRACED)
+
+#define is_task_traced(task) ((task->state & TASK_TRACED) != 0)
+#define is_task_stopped(task) ((task->state & TASK_STOPPED) != 0)
+#define is_task_stopped_or_traced(task) \
+ ((task->state & (TASK_STOPPED | TASK_TRACED)) != 0)
+#define is_task_loadavg(task) ((task->state & TASK_UNINTERRUPTIBLE) != 0)
+
#define __set_task_state(tsk, state_value) \
do { (tsk)->state = (state_value); } while (0)
#define set_task_state(tsk, state_value) \
diff --git a/include/linux/wait.h b/include/linux/wait.h
index 0e68628..0a410a4 100644
--- a/include/linux/wait.h
+++ b/include/linux/wait.h
@@ -152,14 +152,15 @@ int FASTCALL(out_of_line_wait_on_bit(void *, int, int (*)(void *), unsigned));
int FASTCALL(out_of_line_wait_on_bit_lock(void *, int, int (*)(void *), unsigned));
wait_queue_head_t *FASTCALL(bit_waitqueue(void *, int));
-#define wake_up(x) __wake_up(x, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, 1, NULL)
-#define wake_up_nr(x, nr) __wake_up(x, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, nr, NULL)
-#define wake_up_all(x) __wake_up(x, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, 0, NULL)
+#define wake_up(x) __wake_up(x, TASK_NORMAL, 1, NULL)
+#define wake_up_nr(x, nr) __wake_up(x, TASK_NORMAL, nr, NULL)
+#define wake_up_all(x) __wake_up(x, TASK_NORMAL, 0, NULL)
+#define wake_up_locked(x) __wake_up_locked((x), TASK_NORMAL)
+
#define wake_up_interruptible(x) __wake_up(x, TASK_INTERRUPTIBLE, 1, NULL)
#define wake_up_interruptible_nr(x, nr) __wake_up(x, TASK_INTERRUPTIBLE, nr, NULL)
#define wake_up_interruptible_all(x) __wake_up(x, TASK_INTERRUPTIBLE, 0, NULL)
-#define wake_up_locked(x) __wake_up_locked((x), TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE)
-#define wake_up_interruptible_sync(x) __wake_up_sync((x),TASK_INTERRUPTIBLE, 1)
+#define wake_up_interruptible_sync(x) __wake_up_sync((x), TASK_INTERRUPTIBLE, 1)
#define __wait_event(wq, condition) \
do { \
diff --git a/kernel/exit.c b/kernel/exit.c
index 06b24b3..325106a 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -259,7 +259,7 @@ static int has_stopped_jobs(struct pid *pgrp)
struct task_struct *p;
do_each_pid_task(pgrp, PIDTYPE_PGID, p) {
- if (p->state != TASK_STOPPED)
+ if (!is_task_stopped(p))
continue;
retval = 1;
break;
@@ -634,7 +634,7 @@ reparent_thread(struct task_struct *p, struct task_struct *father, int traced)
p->parent = p->real_parent;
add_parent(p);
- if (p->state == TASK_TRACED) {
+ if (is_task_traced(p)) {
/*
* If it was at a trace stop, turn it into
* a normal stop since it's no longer being
@@ -1372,7 +1372,7 @@ static int wait_task_stopped(struct task_struct *p, int delayed_group_leader,
exit_code = p->exit_code;
if (unlikely(!exit_code) ||
- unlikely(p->state & TASK_TRACED))
+ unlikely(is_task_traced(p)))
goto bail_ref;
return wait_noreap_copyout(p, pid, uid,
why, (exit_code << 8) | 0x7f,
@@ -1554,60 +1554,51 @@ repeat:
}
allowed = 1;
- switch (p->state) {
- case TASK_TRACED:
- /*
- * When we hit the race with PTRACE_ATTACH,
- * we will not report this child. But the
- * race means it has not yet been moved to
- * our ptrace_children list, so we need to
- * set the flag here to avoid a spurious ECHILD
- * when the race happens with the only child.
- */
- flag = 1;
- if (!my_ptrace_child(p))
- continue;
- /*FALLTHROUGH*/
- case TASK_STOPPED:
+ if (is_task_stopped_or_traced(p)) {
/*
* It's stopped now, so it might later
* continue, exit, or stop again.
+ *
+ * When we hit the race with PTRACE_ATTACH, we
+ * will not report this child. But the race
+ * means it has not yet been moved to our
+ * ptrace_children list, so we need to set the
+ * flag here to avoid a spurious ECHILD when
+ * the race happens with the only child.
*/
flag = 1;
- if (!(options & WUNTRACED) &&
- !my_ptrace_child(p))
- continue;
+
+ if (!my_ptrace_child(p)) {
+ if (is_task_traced(p))
+ continue;
+ if (!(options & WUNTRACED))
+ continue;
+ }
+
retval = wait_task_stopped(p, ret == 2,
- (options & WNOWAIT),
- infop,
- stat_addr, ru);
+ (options & WNOWAIT), infop,
+ stat_addr, ru);
if (retval == -EAGAIN)
goto repeat;
if (retval != 0) /* He released the lock. */
goto end;
- break;
- default:
- // case EXIT_DEAD:
- if (p->exit_state == EXIT_DEAD)
+ } else if (p->exit_state == EXIT_DEAD) {
+ continue;
+ } else if (p->exit_state == EXIT_ZOMBIE) {
+ /*
+ * Eligible but we cannot release it yet:
+ */
+ if (ret == 2)
+ goto check_continued;
+ if (!likely(options & WEXITED))
continue;
- // case EXIT_ZOMBIE:
- if (p->exit_state == EXIT_ZOMBIE) {
- /*
- * Eligible but we cannot release
- * it yet:
- */
- if (ret == 2)
- goto check_continued;
- if (!likely(options & WEXITED))
- continue;
- retval = wait_task_zombie(
- p, (options & WNOWAIT),
- infop, stat_addr, ru);
- /* He released the lock. */
- if (retval != 0)
- goto end;
- break;
- }
+ retval = wait_task_zombie(p,
+ (options & WNOWAIT), infop,
+ stat_addr, ru);
+ /* He released the lock. */
+ if (retval != 0)
+ goto end;
+ } else {
check_continued:
/*
* It's running now, so it might later
@@ -1616,12 +1607,11 @@ check_continued:
flag = 1;
if (!unlikely(options & WCONTINUED))
continue;
- retval = wait_task_continued(
- p, (options & WNOWAIT),
- infop, stat_addr, ru);
+ retval = wait_task_continued(p,
+ (options & WNOWAIT), infop,
+ stat_addr, ru);
if (retval != 0) /* He released the lock. */
goto end;
- break;
}
}
if (!flag) {
diff --git a/kernel/power/process.c b/kernel/power/process.c
index 3434940..ac0c27a 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -83,10 +83,10 @@ static void freeze_task(struct task_struct *p)
rmb();
if (!frozen(p)) {
set_freeze_flag(p);
- if (p->state == TASK_STOPPED)
+ if (is_task_stopped(p))
force_sig_specific(SIGSTOP, p);
spin_lock_irqsave(&p->sighand->siglock, flags);
- signal_wake_up(p, p->state == TASK_STOPPED);
+ signal_wake_up(p, is_task_stopped(p));
spin_unlock_irqrestore(&p->sighand->siglock, flags);
}
}
@@ -120,8 +120,7 @@ static int try_to_freeze_tasks(int freeze_user_space)
continue;
if (freeze_user_space) {
- if (p->state == TASK_TRACED &&
- frozen(p->parent)) {
+ if (is_task_traced(p) && frozen(p->parent)) {
cancel_freezing(p);
continue;
}
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 82a558b..92a2283 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -50,7 +50,7 @@ void __ptrace_link(struct task_struct *child, struct task_struct *new_parent)
void ptrace_untrace(struct task_struct *child)
{
spin_lock(&child->sighand->siglock);
- if (child->state == TASK_TRACED) {
+ if (is_task_traced(child)) {
if (child->signal->flags & SIGNAL_STOP_STOPPED) {
child->state = TASK_STOPPED;
} else {
@@ -78,7 +78,7 @@ void __ptrace_unlink(struct task_struct *child)
add_parent(child);
}
- if (child->state == TASK_TRACED)
+ if (is_task_traced(child))
ptrace_untrace(child);
}
@@ -102,9 +102,9 @@ int ptrace_check_attach(struct task_struct *child, int kill)
&& child->signal != NULL) {
ret = 0;
spin_lock_irq(&child->sighand->siglock);
- if (child->state == TASK_STOPPED) {
+ if (is_task_stopped(child)) {
child->state = TASK_TRACED;
- } else if (child->state != TASK_TRACED && !kill) {
+ } else if (!is_task_traced(child) && !kill) {
ret = -ESRCH;
}
spin_unlock_irq(&child->sighand->siglock);
diff --git a/kernel/sched.c b/kernel/sched.c
index b533d6d..e3be352 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -944,7 +944,7 @@ static int effective_prio(struct task_struct *p)
*/
static void activate_task(struct rq *rq, struct task_struct *p, int wakeup)
{
- if (p->state == TASK_UNINTERRUPTIBLE)
+ if (is_task_loadavg(p))
rq->nr_uninterruptible--;
enqueue_task(rq, p, wakeup);
@@ -958,7 +958,7 @@ static inline void activate_idle_task(struct task_struct *p, struct rq *rq)
{
update_rq_clock(rq);
- if (p->state == TASK_UNINTERRUPTIBLE)
+ if (is_task_loadavg(p))
rq->nr_uninterruptible--;
enqueue_task(rq, p, 0);
@@ -970,7 +970,7 @@ static inline void activate_idle_task(struct task_struct *p, struct rq *rq)
*/
static void deactivate_task(struct rq *rq, struct task_struct *p, int sleep)
{
- if (p->state == TASK_UNINTERRUPTIBLE)
+ if (is_task_loadavg(p))
rq->nr_uninterruptible++;
dequeue_task(rq, p, sleep);
@@ -1566,8 +1566,7 @@ out:
int fastcall wake_up_process(struct task_struct *p)
{
- return try_to_wake_up(p, TASK_STOPPED | TASK_TRACED |
- TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE, 0);
+ return try_to_wake_up(p, TASK_ALL, 0);
}
EXPORT_SYMBOL(wake_up_process);
@@ -3708,8 +3707,7 @@ void fastcall complete(struct completion *x)
spin_lock_irqsave(&x->wait.lock, flags);
x->done++;
- __wake_up_common(&x->wait, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE,
- 1, 0, NULL);
+ __wake_up_common(&x->wait, TASK_NORMAL, 1, 0, NULL);
spin_unlock_irqrestore(&x->wait.lock, flags);
}
EXPORT_SYMBOL(complete);
@@ -3720,8 +3718,7 @@ void fastcall complete_all(struct completion *x)
spin_lock_irqsave(&x->wait.lock, flags);
x->done += UINT_MAX/2;
- __wake_up_common(&x->wait, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE,
- 0, 0, NULL);
+ __wake_up_common(&x->wait, TASK_NORMAL, 0, 0, NULL);
spin_unlock_irqrestore(&x->wait.lock, flags);
}
EXPORT_SYMBOL(complete_all);
diff --git a/kernel/signal.c b/kernel/signal.c
index 3169bed..53cbac4 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -841,7 +841,7 @@ static inline int wants_signal(int sig, struct task_struct *p)
return 0;
if (sig == SIGKILL)
return 1;
- if (p->state & (TASK_STOPPED | TASK_TRACED))
+ if (is_task_stopped_or_traced(p))
return 0;
return task_curr(p) || !signal_pending(p);
}
@@ -1445,7 +1445,7 @@ void do_notify_parent(struct task_struct *tsk, int sig)
BUG_ON(sig == -1);
/* do_notify_parent_cldstop should have been called instead. */
- BUG_ON(tsk->state & (TASK_STOPPED|TASK_TRACED));
+ BUG_ON(is_task_stopped_or_traced(tsk));
BUG_ON(!tsk->ptrace &&
(tsk->group_leader != tsk || !thread_group_empty(tsk)));
@@ -1712,7 +1712,7 @@ static int do_signal_stop(int signr)
* so this check has no races.
*/
if (!t->exit_state &&
- !(t->state & (TASK_STOPPED|TASK_TRACED))) {
+ !is_task_stopped_or_traced(t)) {
stop_count++;
signal_wake_up(t, 0);
}
diff --git a/kernel/wait.c b/kernel/wait.c
index 444ddbf..f987688 100644
--- a/kernel/wait.c
+++ b/kernel/wait.c
@@ -215,7 +215,7 @@ void fastcall __wake_up_bit(wait_queue_head_t *wq, void *word, int bit)
{
struct wait_bit_key key = __WAIT_BIT_KEY_INITIALIZER(word, bit);
if (waitqueue_active(wq))
- __wake_up(wq, TASK_INTERRUPTIBLE|TASK_UNINTERRUPTIBLE, 1, &key);
+ __wake_up(wq, TASK_NORMAL, 1, &key);
}
EXPORT_SYMBOL(__wake_up_bit);
--
Intel are signing my paycheques ... these opinions are still mine
"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours. We can't possibly take such
a retrograde step."
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists