diff options
Diffstat (limited to 'kernel/fork.c')
| -rw-r--r-- | kernel/fork.c | 22 |
1 files changed, 17 insertions, 5 deletions
diff --git a/kernel/fork.c b/kernel/fork.c index fbea12d7a943..9bd7b65ee418 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -108,8 +108,10 @@ void free_task(struct task_struct *tsk) } EXPORT_SYMBOL(free_task); -void __put_task_struct(struct task_struct *tsk) +void __put_task_struct_cb(struct rcu_head *rhp) { + struct task_struct *tsk = container_of(rhp, struct task_struct, rcu); + WARN_ON(!(tsk->exit_state & (EXIT_DEAD | EXIT_ZOMBIE))); WARN_ON(atomic_read(&tsk->usage)); WARN_ON(tsk == current); @@ -1060,6 +1062,12 @@ static task_t *copy_process(unsigned long clone_flags, p->clear_child_tid = (clone_flags & CLONE_CHILD_CLEARTID) ? child_tidptr: NULL; /* + * sigaltstack should be cleared when sharing the same VM + */ + if ((clone_flags & (CLONE_VM|CLONE_VFORK)) == CLONE_VM) + p->sas_ss_sp = p->sas_ss_size = 0; + + /* * Syscall tracing should be turned off in the child regardless * of CLONE_PTRACE. */ @@ -1470,9 +1478,7 @@ static int unshare_vm(unsigned long unshare_flags, struct mm_struct **new_mmp) if ((unshare_flags & CLONE_VM) && (mm && atomic_read(&mm->mm_users) > 1)) { - *new_mmp = dup_mm(current); - if (!*new_mmp) - return -ENOMEM; + return -EINVAL; } return 0; @@ -1528,6 +1534,12 @@ asmlinkage long sys_unshare(unsigned long unshare_flags) check_unshare_flags(&unshare_flags); + /* Return -EINVAL for all unsupported flags */ + err = -EINVAL; + if (unshare_flags & ~(CLONE_THREAD|CLONE_FS|CLONE_NEWNS|CLONE_SIGHAND| + CLONE_VM|CLONE_FILES|CLONE_SYSVSEM)) + goto bad_unshare_out; + if ((err = unshare_thread(unshare_flags))) goto bad_unshare_out; if ((err = unshare_fs(unshare_flags, &new_fs))) @@ -1561,7 +1573,7 @@ asmlinkage long sys_unshare(unsigned long unshare_flags) if (new_sigh) { sigh = current->sighand; - current->sighand = new_sigh; + rcu_assign_pointer(current->sighand, new_sigh); new_sigh = sigh; } |