diff options
Diffstat (limited to 'kernel/fork.c')
| -rw-r--r-- | kernel/fork.c | 84 |
1 files changed, 57 insertions, 27 deletions
diff --git a/kernel/fork.c b/kernel/fork.c index ac8100e3088a..56e4e07e45f7 100644 --- 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> @@ -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; @@ -368,6 +371,8 @@ void fastcall __mmdrop(struct mm_struct *mm) */ void mmput(struct mm_struct *mm) { + might_sleep(); + if (atomic_dec_and_test(&mm->mm_users)) { exit_aio(mm); exit_mmap(mm); @@ -623,6 +628,7 @@ out: /* * Allocate a new files structure and copy contents from the * passed in files structure. + * errorp will be valid only when the returned files_struct is NULL. */ static struct files_struct *dup_fd(struct files_struct *oldf, int *errorp) { @@ -631,6 +637,7 @@ static struct files_struct *dup_fd(struct files_struct *oldf, int *errorp) int open_files, size, i, expand; struct fdtable *old_fdt, *new_fdt; + *errorp = -ENOMEM; newf = alloc_files(); if (!newf) goto out; @@ -744,7 +751,6 @@ static int copy_files(unsigned long clone_flags, struct task_struct * tsk) * break this. */ tsk->files = NULL; - error = -ENOMEM; newf = dup_fd(oldf, &error); if (!newf) goto out; @@ -871,6 +877,7 @@ 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; } @@ -909,6 +916,15 @@ 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. @@ -917,13 +933,13 @@ 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; @@ -955,6 +971,10 @@ 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) { @@ -989,13 +1009,10 @@ 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); @@ -1032,6 +1049,28 @@ 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 */ @@ -1075,6 +1114,9 @@ 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 */ @@ -1155,18 +1197,6 @@ 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(¤t->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); @@ -1264,9 +1294,9 @@ 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(®s), 0, NULL, NULL, 0); |