Messages in this thread Patch in this message | | | From | (Eric W. Biederman) | Date | Sun, 02 Apr 2017 17:52:58 -0500 | Subject | [RFC][PATCH v2 3/5] clone: Disallown CLONE_THREAD with a shared sighand_struct |
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Old threading libraries used CLONE_SIGHAND without clone thread. Modern threadding libraries always use CLONE_SIGHAND | CLONE_THREAD.
Therefore let's simplify our lives and stop supporting a case no one cares about.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> --- kernel/fork.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/kernel/fork.c b/kernel/fork.c index fe6f1bf32bb9..0632ac1180be 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1515,6 +1515,13 @@ static __latent_entropy struct task_struct *copy_process( if ((clone_flags & CLONE_THREAD) && !(clone_flags & CLONE_SIGHAND)) return ERR_PTR(-EINVAL); + /* Disallow CLONE_THREAD with a shared SIGHAND structure. No + * one cares and supporting it leads to unnecessarily complex + * code. + */ + if ((clone_flags & CLONE_THREAD) && (atomic_read(¤t->sighand->count) > 1)) + return ERR_PTR(-EINVAL); + /* * Shared signal handlers imply shared VM. By way of the above, * thread groups also imply shared VM. Blocking this case allows -- 2.10.1
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