From: Andy Lutomirski <luto@kernel.org>
To: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Garnier <thgarnie@google.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H . Peter Anvin" <hpa@zytor.com>,
Andrey Ryabinin <aryabinin@virtuozzo.com>,
Alexander Potapenko <glider@google.com>,
Dmitry Vyukov <dvyukov@google.com>,
Kees Cook <keescook@chromium.org>,
Andy Lutomirski <luto@kernel.org>,
Arjan van de Ven <arjan@linux.intel.com>,
Paul Gortmaker <paul.gortmaker@windriver.com>,
Borislav Petkov <bp@suse.de>,
"Rafael J . Wysocki" <rjw@rjwysocki.net>,
Len Brown <len.brown@intel.com>, Pavel Machek <pavel@ucw.cz>,
Jiri Kosina <jikos@kernel.org>,
Matt Fleming <matt@codeblueprint.co.uk>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
Juergen Gross <jgross@suse.com>,
Rusty Russell <rusty@rustcorp.com.au>,
Christian Borntraeger <borntraeger@de.ibm.com>,
Fenghua Yu <fenghua.yu@intel.com>
Subject: Re: [PATCH v2 3/3] x86: Make the GDT remapping read-only on 64 bit
Date: Wed, 1 Feb 2017 21:13:55 -0800 [thread overview]
Message-ID: <CALCETrU_WPm+HonkiRtaO0kTTqkfAcyhANp22yPGiSAPkNsRGQ@mail.gmail.com> (raw)
In-Reply-To: <20170201091534.GA25025@gmail.com>
On Wed, Feb 1, 2017 at 1:15 AM, Ingo Molnar <mingo@kernel.org> wrote:
>
> * Thomas Garnier <thgarnie@google.com> wrote:
>
>> This patch makes the GDT remapped pages read-only to prevent corruption.
>> This change is done only on 64 bit.
>
>>
>> - table_base = gdt->address;
>> + table_base = (unsigned long)get_current_direct_gdt();
>
> Instead of spreading these type casts far and wide please introduce another
> accessor the returns 'unsigned long':
>
> get_cpu_gdt_rw_vaddr()
>
That whole function is an abomination. How about replacing 'unsigned
long table_base' with 'struct desc_struct *table'? If you're feeling
really adventurous, *delete* that function and replace all of its
users with something sane.
--Andy
WARNING: multiple messages have this Message-ID (diff)
From: Andy Lutomirski <luto@kernel.org>
To: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Garnier <thgarnie@google.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H . Peter Anvin" <hpa@zytor.com>,
Andrey Ryabinin <aryabinin@virtuozzo.com>,
Alexander Potapenko <glider@google.com>,
Dmitry Vyukov <dvyukov@google.com>,
Kees Cook <keescook@chromium.org>,
Andy Lutomirski <luto@kernel.org>,
Arjan van de Ven <arjan@linux.intel.com>,
Paul Gortmaker <paul.gortmaker@windriver.com>,
Borislav Petkov <bp@suse.de>,
"Rafael J . Wysocki" <rjw@rjwysocki.net>,
Len Brown <len.brown@intel.com>, Pavel Machek <pavel@ucw.cz>,
Jiri Kosina <jikos@kernel.org>,
Matt Fleming <matt@codeblueprint.co.uk>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
Juergen Gross <jgross@suse.com>,
Rusty Russell <rusty@rustcorp.com.au>,
Christian Borntraeger <borntraeger@de.ibm.com>,
Fenghua Yu <fenghua.yu@intel.com>,
Subject: Re: [PATCH v2 3/3] x86: Make the GDT remapping read-only on 64 bit
Date: Wed, 1 Feb 2017 21:13:55 -0800 [thread overview]
Message-ID: <CALCETrU_WPm+HonkiRtaO0kTTqkfAcyhANp22yPGiSAPkNsRGQ@mail.gmail.com> (raw)
In-Reply-To: <20170201091534.GA25025@gmail.com>
On Wed, Feb 1, 2017 at 1:15 AM, Ingo Molnar <mingo@kernel.org> wrote:
>
> * Thomas Garnier <thgarnie@google.com> wrote:
>
>> This patch makes the GDT remapped pages read-only to prevent corruption.
>> This change is done only on 64 bit.
>
>>
>> - table_base = gdt->address;
>> + table_base = (unsigned long)get_current_direct_gdt();
>
> Instead of spreading these type casts far and wide please introduce another
> accessor the returns 'unsigned long':
>
> get_cpu_gdt_rw_vaddr()
>
That whole function is an abomination. How about replacing 'unsigned
long table_base' with 'struct desc_struct *table'? If you're feeling
really adventurous, *delete* that function and replace all of its
users with something sane.
--Andy
WARNING: multiple messages have this Message-ID (diff)
From: Andy Lutomirski <luto@kernel.org>
To: Ingo Molnar <mingo@kernel.org>
Cc: "Thomas Garnier" <thgarnie@google.com>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Ingo Molnar" <mingo@redhat.com>,
"H . Peter Anvin" <hpa@zytor.com>,
"Andrey Ryabinin" <aryabinin@virtuozzo.com>,
"Alexander Potapenko" <glider@google.com>,
"Dmitry Vyukov" <dvyukov@google.com>,
"Kees Cook" <keescook@chromium.org>,
"Andy Lutomirski" <luto@kernel.org>,
"Arjan van de Ven" <arjan@linux.intel.com>,
"Paul Gortmaker" <paul.gortmaker@windriver.com>,
"Borislav Petkov" <bp@suse.de>,
"Rafael J . Wysocki" <rjw@rjwysocki.net>,
"Len Brown" <len.brown@intel.com>, "Pavel Machek" <pavel@ucw.cz>,
"Jiri Kosina" <jikos@kernel.org>,
"Matt Fleming" <matt@codeblueprint.co.uk>,
"Ard Biesheuvel" <ard.biesheuvel@linaro.org>,
"Boris Ostrovsky" <boris.ostrovsky@oracle.com>,
"Juergen Gross" <jgross@suse.com>,
"Rusty Russell" <rusty@rustcorp.com.au>,
"Christian Borntraeger" <borntraeger@de.ibm.com>,
"Fenghua Yu" <fenghua.yu@intel.com>,
"He Chen" <he.chen@linux.intel.com>,
"Brian Gerst" <brgerst@gmail.com>,
"Luis R . Rodriguez" <mcgrof@kernel.org>,
"Adam Buchbinder" <adam.buchbinder@gmail.com>,
"Stanislaw Gruszka" <sgruszka@redhat.com>,
"Arnd Bergmann" <arnd@arndb.de>,
"Dave Hansen" <dave.hansen@intel.com>,
"Chen Yucong" <slaoub@gmail.com>,
"Vitaly Kuznetsov" <vkuznets@redhat.com>,
"David Vrabel" <david.vrabel@citrix.com>,
"Josh Poimboeuf" <jpoimboe@redhat.com>,
"Tim Chen" <tim.c.chen@linux.intel.com>,
"Rik van Riel" <riel@redhat.com>,
"Andi Kleen" <ak@linux.intel.com>, "Jiri Olsa" <jolsa@redhat.com>,
"Prarit Bhargava" <prarit@redhat.com>,
"Michael Ellerman" <mpe@ellerman.id.au>,
"Joerg Roedel" <joro@8bytes.org>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Radim Krčmář" <rkrcmar@redhat.com>, "X86 ML" <x86@kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
kasan-dev <kasan-dev@googlegroups.com>,
"linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>,
"linux-efi@vger.kernel.org" <linux-efi@vger.kernel.org>,
"xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>,
lguest@lists.ozlabs.org, "kvm list" <kvm@vger.kernel.org>,
"kernel-hardening@lists.openwall.com"
<kernel-hardening@lists.openwall.com>
Subject: [kernel-hardening] Re: [PATCH v2 3/3] x86: Make the GDT remapping read-only on 64 bit
Date: Wed, 1 Feb 2017 21:13:55 -0800 [thread overview]
Message-ID: <CALCETrU_WPm+HonkiRtaO0kTTqkfAcyhANp22yPGiSAPkNsRGQ@mail.gmail.com> (raw)
In-Reply-To: <20170201091534.GA25025@gmail.com>
On Wed, Feb 1, 2017 at 1:15 AM, Ingo Molnar <mingo@kernel.org> wrote:
>
> * Thomas Garnier <thgarnie@google.com> wrote:
>
>> This patch makes the GDT remapped pages read-only to prevent corruption.
>> This change is done only on 64 bit.
>
>>
>> - table_base = gdt->address;
>> + table_base = (unsigned long)get_current_direct_gdt();
>
> Instead of spreading these type casts far and wide please introduce another
> accessor the returns 'unsigned long':
>
> get_cpu_gdt_rw_vaddr()
>
That whole function is an abomination. How about replacing 'unsigned
long table_base' with 'struct desc_struct *table'? If you're feeling
really adventurous, *delete* that function and replace all of its
users with something sane.
--Andy
next prev parent reply other threads:[~2017-02-02 5:13 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-26 16:59 [PATCH v2 1/3] x86/mm: Adapt MODULES_END based on Fixmap section size Thomas Garnier
2017-01-26 16:59 ` [kernel-hardening] " Thomas Garnier
2017-01-26 16:59 ` Thomas Garnier
2017-01-26 16:59 ` Thomas Garnier
2017-01-26 16:59 ` [PATCH v2 2/3] x86: Remap GDT tables in the Fixmap section Thomas Garnier
2017-01-26 16:59 ` Thomas Garnier
2017-01-26 16:59 ` [kernel-hardening] " Thomas Garnier
2017-01-26 16:59 ` Thomas Garnier
2017-01-26 16:59 ` Thomas Garnier
2017-01-26 18:52 ` Andy Lutomirski
2017-01-26 18:52 ` [kernel-hardening] " Andy Lutomirski
2017-01-26 19:10 ` Thomas Garnier
2017-01-26 19:10 ` [kernel-hardening] " Thomas Garnier
2017-01-26 19:10 ` Thomas Garnier
2017-01-26 18:52 ` Andy Lutomirski
2017-01-26 16:59 ` [PATCH v2 3/3] x86: Make the GDT remapping read-only on 64 bit Thomas Garnier
2017-01-26 16:59 ` Thomas Garnier
2017-01-26 16:59 ` [kernel-hardening] " Thomas Garnier
2017-01-26 16:59 ` Thomas Garnier
2017-01-26 16:59 ` Thomas Garnier
2017-02-01 9:15 ` Ingo Molnar
2017-02-01 9:15 ` [kernel-hardening] " Ingo Molnar
2017-02-01 9:15 ` Ingo Molnar
2017-02-02 5:13 ` Andy Lutomirski
2017-02-02 5:13 ` Andy Lutomirski [this message]
2017-02-02 5:13 ` [kernel-hardening] " Andy Lutomirski
2017-02-02 5:13 ` Andy Lutomirski
2017-02-02 7:12 ` Ingo Molnar
2017-02-02 7:12 ` [kernel-hardening] " Ingo Molnar
2017-02-02 7:12 ` Ingo Molnar
2017-02-02 7:12 ` Ingo Molnar
2017-02-01 9:15 ` Ingo Molnar
2017-02-02 5:14 ` Andy Lutomirski
2017-02-02 5:14 ` Andy Lutomirski
2017-02-02 5:14 ` [kernel-hardening] " Andy Lutomirski
2017-02-06 22:10 ` Thomas Garnier
2017-02-06 22:10 ` Thomas Garnier
2017-02-06 22:10 ` [kernel-hardening] " Thomas Garnier
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