linux-kernel - Re: [PATCH v7 02/26] x86/mm: Relocate page fault error codes to traps.h

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Date:   Sun, 21 May 2017 16:23:30 +0200
From:   Borislav Petkov <bp@...e.de>
To:     Ricardo Neri <ricardo.neri-calderon@...ux.intel.com>
Cc:     Ingo Molnar <mingo@...hat.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        "H. Peter Anvin" <hpa@...or.com>,
        Andy Lutomirski <luto@...nel.org>,
        Peter Zijlstra <peterz@...radead.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Brian Gerst <brgerst@...il.com>,
        Chris Metcalf <cmetcalf@...lanox.com>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Liang Z Li <liang.z.li@...el.com>,
        Masami Hiramatsu <mhiramat@...nel.org>,
        Huang Rui <ray.huang@....com>, Jiri Slaby <jslaby@...e.cz>,
        Jonathan Corbet <corbet@....net>,
        "Michael S. Tsirkin" <mst@...hat.com>,
        Paul Gortmaker <paul.gortmaker@...driver.com>,
        Vlastimil Babka <vbabka@...e.cz>,
        Chen Yucong <slaoub@...il.com>,
        Alexandre Julliard <julliard@...ehq.org>,
        Stas Sergeev <stsp@...t.ru>, Fenghua Yu <fenghua.yu@...el.com>,
        "Ravi V. Shankar" <ravi.v.shankar@...el.com>,
        Shuah Khan <shuah@...nel.org>, linux-kernel@...r.kernel.org,
        x86@...nel.org, linux-msdos@...r.kernel.org, wine-devel@...ehq.org,
        "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>,
        Josh Poimboeuf <jpoimboe@...hat.com>
Subject: Re: [PATCH v7 02/26] x86/mm: Relocate page fault error codes to
 traps.h

On Fri, May 05, 2017 at 11:17:00AM -0700, Ricardo Neri wrote:
> Up to this point, only fault.c used the definitions of the page fault error
> codes. Thus, it made sense to keep them within such file. Other portions of
> code might be interested in those definitions too. For instance, the User-
> Mode Instruction Prevention emulation code will use such definitions to
> emulate a page fault when it is unable to successfully copy the results
> of the emulated instructions to user space.
> 
> While relocating the error code enumeration, the prefix X86_ is used to
> make it consistent with the rest of the definitions in traps.h. Of course,
> code using the enumeration had to be updated as well. No functional changes
> were performed.
> 
> Cc: Thomas Gleixner <tglx@...utronix.de>
> Cc: Ingo Molnar <mingo@...hat.com>
> Cc: "H. Peter Anvin" <hpa@...or.com>
> Cc: Andy Lutomirski <luto@...nel.org>
> Cc: "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>
> Cc: Josh Poimboeuf <jpoimboe@...hat.com>
> Cc: Dave Hansen <dave.hansen@...ux.intel.com>
> Cc: Paul Gortmaker <paul.gortmaker@...driver.com>
> Cc: x86@...nel.org
> Reviewed-by: Andy Lutomirski <luto@...nel.org>
> Signed-off-by: Ricardo Neri <ricardo.neri-calderon@...ux.intel.com>
> ---
>  arch/x86/include/asm/traps.h | 18 +++++++++
>  arch/x86/mm/fault.c          | 88 +++++++++++++++++---------------------------
>  2 files changed, 52 insertions(+), 54 deletions(-)

...

> @@ -1382,7 +1362,7 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code,
>  	 * space check, thus avoiding the deadlock:
>  	 */
>  	if (unlikely(!down_read_trylock(&mm->mmap_sem))) {
> -		if ((error_code & PF_USER) == 0 &&
> +		if ((error_code & X86_PF_USER) == 0 &&

	if (!(error_code & X86_PF_USER))

With that fixed:

Reviewed-by: Borislav Petkov <bp@...e.de>

-- 
Regards/Gruss,
    Boris.

SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg)
--