lkml.org 
[lkml]   [2002]   [Sep]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Subject[PATCH] Fix for ptrace breakage
From
Date
Hi,

This patch fixes the following,

- race condition of ptrace flag
- sent odd signal to the tracer
- broken before behavior

And some cleanup.

Please apply.
--
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>

--- linux-2.5.35/kernel/exit.c~ 2002-09-16 17:41:59.000000000 +0900
+++ linux-2.5.35/kernel/exit.c 2002-09-16 17:28:01.000000000 +0900
@@ -221,7 +221,6 @@ void reparent_to_init(void)
/* Set the exit signal to SIGCHLD so we signal init on exit */
current->exit_signal = SIGCHLD;

- current->ptrace = 0;
if ((current->policy == SCHED_NORMAL) && (task_nice(current) < 0))
set_user_nice(current, 0);
/* cpus_allowed? */
@@ -464,50 +463,35 @@ static inline void forget_original_paren
}
list_for_each(_p, &father->ptrace_children) {
p = list_entry(_p,struct task_struct,ptrace_list);
+ list_del_init(&p->ptrace_list);
reparent_thread(p, reaper, child_reaper);
+ if (p->parent != p->real_parent)
+ list_add(&p->ptrace_list, &p->real_parent->ptrace_children);
}
}

-static inline void zap_thread(task_t *p, task_t *father, int traced)
+static inline void zap_thread(task_t *p, task_t *father)
{
- /* If someone else is tracing this thread, preserve the ptrace links. */
- if (unlikely(traced)) {
- task_t *trace_task = p->parent;
- int ptrace_flag = p->ptrace;
- BUG_ON (ptrace_flag == 0);
-
- __ptrace_unlink(p);
- p->ptrace = ptrace_flag;
- __ptrace_link(p, trace_task);
- } else {
- /*
- * Otherwise, if we were tracing this thread, untrace it.
- * If we were only tracing the thread (i.e. not its real
- * parent), stop here.
- */
- ptrace_unlink (p);
- if (p->parent != father) {
- BUG_ON(p->parent != p->real_parent);
- return;
- }
- list_del_init(&p->sibling);
- p->parent = p->real_parent;
- list_add_tail(&p->sibling, &p->parent->children);
- }
+ ptrace_unlink(p);

+ remove_parent(p);
+ p->parent = p->real_parent;
+ add_parent(p, p->parent);
if (p->state == TASK_ZOMBIE && p->exit_signal != -1)
do_notify_parent(p, p->exit_signal);
+
/*
* process group orphan check
* Case ii: Our child is in a different pgrp
* than we are, and it was the only connection
* outside, so the child pgrp is now orphaned.
*/
- if ((p->pgrp != current->pgrp) &&
- (p->session == current->session)) {
+ if ((p->pgrp != father->pgrp) &&
+ (p->session == father->session)) {
int pgrp = p->pgrp;

- if (__will_become_orphaned_pgrp(pgrp, 0) && __has_stopped_jobs(pgrp)) {
+ if (__will_become_orphaned_pgrp(pgrp, 0) &&
+ __has_stopped_jobs(pgrp)) {
__kill_pg_info(SIGHUP, (void *)1, pgrp);
__kill_pg_info(SIGCONT, (void *)1, pgrp);
}
@@ -520,7 +504,7 @@ static inline void zap_thread(task_t *p,
*/
static void exit_notify(void)
{
- struct task_struct *t;
+ struct task_struct *t, *p;

write_lock_irq(&tasklist_lock);

@@ -580,10 +564,8 @@ static void exit_notify(void)
if (current->exit_signal != -1)
do_notify_parent(current, current->exit_signal);

- while (!list_empty(&current->children))
- zap_thread(list_entry(current->children.next,struct task_struct,sibling), current, 0);
- while (!list_empty(&current->ptrace_children))
- zap_thread(list_entry(current->ptrace_children.next,struct task_struct,ptrace_list), current, 1);
+ while ((p = eldest_child(current)) != NULL)
+ zap_thread(p, current);
BUG_ON(!list_empty(&current->children));

current->state = TASK_ZOMBIE;
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
\
 
 \ /
  Last update: 2005-03-22 13:28    [W:0.074 / U:0.240 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site