On Thu, Aug 26, 2021 at 9:49 AM Borislav Petkov [off-list ref] wrote:

On Fri, Aug 20, 2021 at 11:11:54AM -0700, Yu-cheng Yu wrote:

quoted

diff --git a/arch/x86/kernel/shstk.c b/arch/x86/kernel/shstk.c
index 5993aa8db338..7c1ca2476a5e 100644
--- a/arch/x86/kernel/shstk.c
+++ b/arch/x86/kernel/shstk.c

@@ -75,6 +75,61 @@ int shstk_setup(void)
      return err;
 }

+int shstk_alloc_thread_stack(struct task_struct *tsk, unsigned long clone_flags,
+                          unsigned long stack_size)
+{
+     struct thread_shstk *shstk = &tsk->thread.shstk;
+     struct cet_user_state *state;
+     unsigned long addr;
+
+     if (!shstk->size)
+             return 0;
+
+     /*
+      * Earlier clone() does not pass stack_size.  Use RLIMIT_STACK and

What is "earlier clone()"?

clone() doesn't have stack size info which was added to clone3().

quoted

+      * cap to 4 GB.
+      */

--
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette

-- 
H.J.