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Date:   Wed, 3 Oct 2018 17:08:03 +0200
From:   Eugene Syromiatnikov <esyr@redhat.com>
To:     Yu-cheng Yu <yu-cheng.yu@intel.com>
Cc:     x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, linux-kernel@vger.kernel.org,
        linux-doc@vger.kernel.org, linux-mm@kvack.org,
        linux-arch@vger.kernel.org, linux-api@vger.kernel.org,
        Arnd Bergmann <arnd@arndb.de>,
        Andy Lutomirski <luto@amacapital.net>,
        Balbir Singh <bsingharora@gmail.com>,
        Cyrill Gorcunov <gorcunov@gmail.com>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Florian Weimer <fweimer@redhat.com>,
        "H.J. Lu" <hjl.tools@gmail.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>,
        Vedvyas Shanbhogue <vedvyas.shanbhogue@intel.com>
Subject: Re: [RFC PATCH v4 18/27] x86/cet/shstk: User-mode shadow stack
 support
Message-ID: <20181003150754.GC32759@asgard.redhat.com>
References: <20180921150351.20898-1-yu-cheng.yu@intel.com>
 <20180921150351.20898-19-yu-cheng.yu@intel.com>
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On Fri, Sep 21, 2018 at 08:03:42AM -0700, Yu-cheng Yu wrote:

> diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
> index 5ea1d64cb0b4..b20450dde5b7 100644
> --- a/fs/proc/task_mmu.c
> +++ b/fs/proc/task_mmu.c
> @@ -652,6 +652,9 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
>  		[ilog2(VM_PKEY_BIT4)]	= "",
>  #endif
>  #endif /* CONFIG_ARCH_HAS_PKEYS */
> +#ifdef CONFIG_X86_INTEL_SHADOW_STACK_USER
> +		[ilog2(VM_SHSTK)]	= "ss"
> +#endif

It's probably makes sense to have this hunk as a part of "x86/cet/shstk:
Add Kconfig option for user-mode shadow stack", where VM_SHSTK was
initially introduced.