X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=kernel%2Ffork.c;h=b25802065031e7612a5733838459d41008bd31f6;hb=6e8dcee3e63f5a2cba4affff4bbb6e228f4b258a;hp=876b31cd822d2669b5831b31707aabfdba676304;hpb=1363c3cd8603a913a27e2995dccbd70d5312d8e6;p=linux-2.6

diff --git a/kernel/fork.c b/kernel/fork.c
index 876b31cd82..b258020650 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -176,6 +176,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig)
 
 	/* One for us, one for whoever does the "release_task()" (usually parent) */
 	atomic_set(&tsk->usage,2);
+	atomic_set(&tsk->fs_excl, 0);
 	return tsk;
 }
 
@@ -208,8 +209,10 @@ static inline int dup_mmap(struct mm_struct * mm, struct mm_struct * oldmm)
 		struct file *file;
 
 		if (mpnt->vm_flags & VM_DONTCOPY) {
+			long pages = vma_pages(mpnt);
+			mm->total_vm -= pages;
 			__vm_stat_account(mm, mpnt->vm_flags, mpnt->vm_file,
-							-vma_pages(mpnt));
+								-pages);
 			continue;
 		}
 		charge = 0;
@@ -250,8 +253,9 @@ static inline int dup_mmap(struct mm_struct * mm, struct mm_struct * oldmm)
 
 		/*
 		 * Link in the new vma and copy the page table entries:
-		 * link in first so that swapoff can see swap entries,
-		 * and try_to_unmap_one's find_vma find the new vma.
+		 * link in first so that swapoff can see swap entries.
+		 * Note that, exceptionally, here the vma is inserted
+		 * without holding mm->mmap_sem.
 		 */
 		spin_lock(&mm->page_table_lock);
 		*pprev = tmp;
@@ -991,6 +995,9 @@ static task_t *copy_process(unsigned long clone_flags,
 	 * of CLONE_PTRACE.
 	 */
 	clear_tsk_thread_flag(p, TIF_SYSCALL_TRACE);
+#ifdef TIF_SYSCALL_EMU
+	clear_tsk_thread_flag(p, TIF_SYSCALL_EMU);
+#endif
 
 	/* Our parent execution domain becomes current domain
 	   These must match for thread signalling to apply */
@@ -1002,9 +1009,6 @@ static task_t *copy_process(unsigned long clone_flags,
 	p->pdeath_signal = 0;
 	p->exit_state = 0;
 
-	/* Perform scheduler related setup */
-	sched_fork(p);
-
 	/*
 	 * Ok, make it visible to the rest of the system.
 	 * We dont wake it up yet.
@@ -1013,18 +1017,24 @@ static task_t *copy_process(unsigned long clone_flags,
 	INIT_LIST_HEAD(&p->ptrace_children);
 	INIT_LIST_HEAD(&p->ptrace_list);
 
+	/* Perform scheduler related setup. Assign this task to a CPU. */
+	sched_fork(p, clone_flags);
+
 	/* Need tasklist lock for parent etc handling! */
 	write_lock_irq(&tasklist_lock);
 
 	/*
-	 * The task hasn't been attached yet, so cpus_allowed mask cannot
-	 * have changed. The cpus_allowed mask of the parent may have
-	 * changed after it was copied first time, and it may then move to
-	 * another CPU - so we re-copy it here and set the child's CPU to
-	 * the parent's CPU. This avoids alot of nasty races.
+	 * The task hasn't been attached yet, so its cpus_allowed mask will
+	 * not be changed, nor will its assigned CPU.
+	 *
+	 * The cpus_allowed mask of the parent may have changed after it was
+	 * copied first time - so re-copy it here, then check the child's CPU
+	 * to ensure it is on a valid CPU (and if not, just force it back to
+	 * parent's CPU). This avoids alot of nasty races.
 	 */
 	p->cpus_allowed = current->cpus_allowed;
-	set_task_cpu(p, smp_processor_id());
+	if (unlikely(!cpu_isset(task_cpu(p), p->cpus_allowed)))
+		set_task_cpu(p, smp_processor_id());
 
 	/*
 	 * Check for pending SIGKILL! The new thread should not be allowed
@@ -1086,6 +1096,11 @@ static task_t *copy_process(unsigned long clone_flags,
 		spin_unlock(&current->sighand->siglock);
 	}
 
+	/*
+	 * inherit ioprio
+	 */
+	p->ioprio = current->ioprio;
+
 	SET_LINKS(p);
 	if (unlikely(p->ptrace & PT_PTRACED))
 		__ptrace_link(p, current->parent);
@@ -1101,6 +1116,9 @@ static task_t *copy_process(unsigned long clone_flags,
 			__get_cpu_var(process_counts)++;
 	}
 
+	if (!current->signal->tty && p->signal->tty)
+		p->signal->tty = NULL;
+
 	nr_threads++;
 	total_forks++;
 	write_unlock_irq(&tasklist_lock);