[PATCH] ptrace: make pid of child process available for PTRACE_EVENT_VFORK_DONE

[pandora-kernel.git] / kernel / fork.c

diff --git a/kernel/fork.c b/kernel/fork.c
index 49adc0e..aa36c43 100644 (file)
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -11,7 +11,6 @@
  * management can be a bitch. See 'mm/memory.c': 'copy_page_range()'
  */
 
-#include <linux/config.h>
 #include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/unistd.h>
@@ -44,6 +43,8 @@
 #include <linux/rmap.h>
 #include <linux/acct.h>
 #include <linux/cn_proc.h>
+#include <linux/delayacct.h>
+#include <linux/taskstats_kern.h>
 
 #include <asm/pgtable.h>
 #include <asm/pgalloc.h>
@@ -62,9 +63,7 @@ int max_threads;              /* tunable limit on nr_threads */
 
 DEFINE_PER_CPU(unsigned long, process_counts) = 0;
 
- __cacheline_aligned DEFINE_RWLOCK(tasklist_lock);  /* outer */
-
-EXPORT_SYMBOL(tasklist_lock);
+__cacheline_aligned DEFINE_RWLOCK(tasklist_lock);  /* outer */
 
 int nr_processes(void)
 {
@@ -104,6 +103,7 @@ static kmem_cache_t *mm_cachep;
 void free_task(struct task_struct *tsk)
 {
        free_thread_info(tsk->thread_info);
+       rt_mutex_debug_task_free(tsk);
        free_task_struct(tsk);
 }
 EXPORT_SYMBOL(free_task);
@@ -193,7 +193,10 @@ static inline int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
 
        down_write(&oldmm->mmap_sem);
        flush_cache_mm(oldmm);
-       down_write(&mm->mmap_sem);
+       /*
+        * Not linked in yet - no deadlock potential:
+        */
+       down_write_nested(&mm->mmap_sem, SINGLE_DEPTH_NESTING);
 
        mm->locked_vm = 0;
        mm->mmap = NULL;
@@ -817,6 +820,7 @@ static inline int copy_signal(unsigned long clone_flags, struct task_struct * ts
        if (clone_flags & CLONE_THREAD) {
                atomic_inc(&current->signal->count);
                atomic_inc(&current->signal->live);
+               taskstats_tgid_alloc(current->signal);
                return 0;
        }
        sig = kmem_cache_alloc(signal_cachep, GFP_KERNEL);
@@ -861,6 +865,7 @@ static inline int copy_signal(unsigned long clone_flags, struct task_struct * ts
        INIT_LIST_HEAD(&sig->cpu_timers[0]);
        INIT_LIST_HEAD(&sig->cpu_timers[1]);
        INIT_LIST_HEAD(&sig->cpu_timers[2]);
+       taskstats_tgid_init(sig);
 
        task_lock(current->group_leader);
        memcpy(sig->rlim, current->signal->rlim, sizeof sig->rlim);
@@ -874,6 +879,7 @@ static inline int copy_signal(unsigned long clone_flags, struct task_struct * ts
                tsk->it_prof_expires =
                        secs_to_cputime(sig->rlim[RLIMIT_CPU].rlim_cur);
        }
+       acct_init_pacct(&sig->pacct);
 
        return 0;
 }
@@ -881,6 +887,7 @@ static inline int copy_signal(unsigned long clone_flags, struct task_struct * ts
 void __cleanup_signal(struct signal_struct *sig)
 {
        exit_thread_group_keys(sig);
+       taskstats_tgid_free(sig);
        kmem_cache_free(signal_cachep, sig);
 }
 
@@ -912,6 +919,15 @@ asmlinkage long sys_set_tid_address(int __user *tidptr)
        return current->pid;
 }
 
+static inline void rt_mutex_init_task(struct task_struct *p)
+{
+#ifdef CONFIG_RT_MUTEXES
+       spin_lock_init(&p->pi_lock);
+       plist_head_init(&p->pi_waiters, &p->pi_lock);
+       p->pi_blocked_on = NULL;
+#endif
+}
+
 /*
  * This creates a new process as a copy of the old one,
  * but does not actually start it yet.
@@ -920,13 +936,13 @@ asmlinkage long sys_set_tid_address(int __user *tidptr)
  * parts of the process environment (as per the clone
  * flags). The actual kick-off is left to the caller.
  */
-static task_t *copy_process(unsigned long clone_flags,
-                                unsigned long stack_start,
-                                struct pt_regs *regs,
-                                unsigned long stack_size,
-                                int __user *parent_tidptr,
-                                int __user *child_tidptr,
-                                int pid)
+static struct task_struct *copy_process(unsigned long clone_flags,
+                                       unsigned long stack_start,
+                                       struct pt_regs *regs,
+                                       unsigned long stack_size,
+                                       int __user *parent_tidptr,
+                                       int __user *child_tidptr,
+                                       int pid)
 {
        int retval;
        struct task_struct *p = NULL;
@@ -958,6 +974,10 @@ static task_t *copy_process(unsigned long clone_flags,
        if (!p)
                goto fork_out;
 
+#ifdef CONFIG_TRACE_IRQFLAGS
+       DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled);
+       DEBUG_LOCKS_WARN_ON(!p->softirqs_enabled);
+#endif
        retval = -EAGAIN;
        if (atomic_read(&p->user->processes) >=
                        p->signal->rlim[RLIMIT_NPROC].rlim_cur) {
@@ -985,6 +1005,7 @@ static task_t *copy_process(unsigned long clone_flags,
                goto bad_fork_cleanup_put_domain;
 
        p->did_exec = 0;
+       delayacct_tsk_init(p);  /* Must remain after dup_task_struct() */
        copy_flags(clone_flags, p);
        p->pid = pid;
        retval = -EFAULT;
@@ -992,13 +1013,10 @@ static task_t *copy_process(unsigned long clone_flags,
                if (put_user(p->pid, parent_tidptr))
                        goto bad_fork_cleanup;
 
-       p->proc_dentry = NULL;
-
        INIT_LIST_HEAD(&p->children);
        INIT_LIST_HEAD(&p->sibling);
        p->vfork_done = NULL;
        spin_lock_init(&p->alloc_lock);
-       spin_lock_init(&p->proc_lock);
 
        clear_tsk_thread_flag(p, TIF_SIGPENDING);
        init_sigpending(&p->pending);
@@ -1035,6 +1053,28 @@ static task_t *copy_process(unsigned long clone_flags,
        }
        mpol_fix_fork_child_flag(p);
 #endif
+#ifdef CONFIG_TRACE_IRQFLAGS
+       p->irq_events = 0;
+       p->hardirqs_enabled = 0;
+       p->hardirq_enable_ip = 0;
+       p->hardirq_enable_event = 0;
+       p->hardirq_disable_ip = _THIS_IP_;
+       p->hardirq_disable_event = 0;
+       p->softirqs_enabled = 1;
+       p->softirq_enable_ip = _THIS_IP_;
+       p->softirq_enable_event = 0;
+       p->softirq_disable_ip = 0;
+       p->softirq_disable_event = 0;
+       p->hardirq_context = 0;
+       p->softirq_context = 0;
+#endif
+#ifdef CONFIG_LOCKDEP
+       p->lockdep_depth = 0; /* no locks held yet */
+       p->curr_chain_key = 0;
+       p->lockdep_recursion = 0;
+#endif
+
+       rt_mutex_init_task(p);
 
 #ifdef CONFIG_DEBUG_MUTEXES
        p->blocked_on = NULL; /* not blocked yet */
@@ -1078,6 +1118,9 @@ static task_t *copy_process(unsigned long clone_flags,
 #ifdef CONFIG_COMPAT
        p->compat_robust_list = NULL;
 #endif
+       INIT_LIST_HEAD(&p->pi_state_list);
+       p->pi_state_cache = NULL;
+
        /*
         * sigaltstack should be cleared when sharing the same VM
         */
@@ -1158,18 +1201,6 @@ static task_t *copy_process(unsigned long clone_flags,
        }
 
        if (clone_flags & CLONE_THREAD) {
-               /*
-                * Important: if an exit-all has been started then
-                * do not create this new thread - the whole thread
-                * group is supposed to exit anyway.
-                */
-               if (current->signal->flags & SIGNAL_GROUP_EXIT) {
-                       spin_unlock(&current->sighand->siglock);
-                       write_unlock_irq(&tasklist_lock);
-                       retval = -EAGAIN;
-                       goto bad_fork_cleanup_namespace;
-               }
-
                p->group_leader = current->group_leader;
                list_add_tail_rcu(&p->thread_group, &p->group_leader->thread_group);
 
@@ -1267,9 +1298,9 @@ struct pt_regs * __devinit __attribute__((weak)) idle_regs(struct pt_regs *regs)
        return regs;
 }
 
-task_t * __devinit fork_idle(int cpu)
+struct task_struct * __devinit fork_idle(int cpu)
 {
-       task_t *task;
+       struct task_struct *task;
        struct pt_regs regs;
 
        task = copy_process(CLONE_VM, 0, idle_regs(&regs), 0, NULL, NULL, 0);
@@ -1356,8 +1387,10 @@ long do_fork(unsigned long clone_flags,
 
                if (clone_flags & CLONE_VFORK) {
                        wait_for_completion(&vfork);
-                       if (unlikely (current->ptrace & PT_TRACE_VFORK_DONE))
+                       if (unlikely (current->ptrace & PT_TRACE_VFORK_DONE)) {
+                               current->ptrace_message = nr;
                                ptrace_notify ((PTRACE_EVENT_VFORK_DONE << 8) | SIGTRAP);
+                       }
                }
        } else {
                free_pid(pid);