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Date:   Thu, 26 Aug 2021 19:28:33 +0200
From:   Borislav Petkov <bp@alien8.de>
To:     "H.J. Lu" <hjl.tools@gmail.com>
Cc:     Yu-cheng Yu <yu-cheng.yu@intel.com>,
        the arch/x86 maintainers <x86@kernel.org>,
        "H. Peter Anvin" <hpa@zytor.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>,
        LKML <linux-kernel@vger.kernel.org>,
        "open list:DOCUMENTATION" <linux-doc@vger.kernel.org>,
        Linux-MM <linux-mm@kvack.org>,
        linux-arch <linux-arch@vger.kernel.org>,
        Linux API <linux-api@vger.kernel.org>,
        Arnd Bergmann <arnd@arndb.de>,
        Andy Lutomirski <luto@kernel.org>,
        Balbir Singh <bsingharora@gmail.com>,
        Cyrill Gorcunov <gorcunov@gmail.com>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Eugene Syromiatnikov <esyr@redhat.com>,
        Florian Weimer <fweimer@redhat.com>,
        Jann Horn <jannh@google.com>, Jonathan Corbet <corbet@lwn.net>,
        Kees Cook <keescook@chromium.org>,
        Mike Kravetz <mike.kravetz@oracle.com>,
        Nadav Amit <nadav.amit@gmail.com>,
        Oleg Nesterov <oleg@redhat.com>, Pavel Machek <pavel@ucw.cz>,
        Peter Zijlstra <peterz@infradead.org>,
        Randy Dunlap <rdunlap@infradead.org>,
        "Ravi V. Shankar" <ravi.v.shankar@intel.com>,
        Dave Martin <Dave.Martin@arm.com>,
        Weijiang Yang <weijiang.yang@intel.com>,
        Pengfei Xu <pengfei.xu@intel.com>,
        Haitao Huang <haitao.huang@intel.com>,
        Rick P Edgecombe <rick.p.edgecombe@intel.com>
Subject: Re: [PATCH v29 25/32] x86/cet/shstk: Handle thread shadow stack
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References: <20210820181201.31490-1-yu-cheng.yu@intel.com>
 <20210820181201.31490-26-yu-cheng.yu@intel.com>
 <YSfGUlGJdV/5EcBs@zn.tnic>
 <CAMe9rOoo5wC7AWbo3WO_GWvT5CXV3r3ysZ2qB8ZPi=giRBDetg@mail.gmail.com>
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On Thu, Aug 26, 2021 at 10:22:29AM -0700, H.J. Lu wrote:
> > > +     /*
> > > +      * 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().

/me goes and reads the manpage...

   clone3()
       The  clone3()  system call provides a superset of the functionality of the older
       clone() interface.  It also provides a number of  API  improvements,  including:
       space  for additional flags bits; cleaner separation in the use of various argu‐
       ments; and the ability to specify the size of the child's stack area.

Aha, Yu-cheng, pls use those words to make your comment understandable.

Thx.

-- 
Regards/Gruss,
    Boris.

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