From: "H. Peter Anvin" <hpa@zytor.com>
To: Vasiliy Kulikov <segoon@openwall.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
kernel-hardening@lists.openwall.com,
Peter Zijlstra <peterz@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>,
x86@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: [kernel-hardening] Re: [RFC] x86, mm: start mmap allocation for libs from low addresses
Date: Mon, 22 Aug 2011 13:17:47 -0700 [thread overview]
Message-ID: <4E52B96B.8040404@zytor.com> (raw)
In-Reply-To: <20110822201418.GA3176@albatros>
On 08/22/2011 01:14 PM, Vasiliy Kulikov wrote:
>
>> Code-wise:
>>
>> The code is horrific; it is full of open-coded magic numbers;
>
> Agreed, the magic needs macro definition and comments.
>
>> it also
>> puts a function called arch_get_unmapped_exec_area() in a generic file,
>> which could best be described as "WTF" -- the arch_ prefix we use
>> specifically to denote a per-architecture hook function.
>
> Agreed. But I'd want to leave it in mm/mmap.c as it's likely be used by
> other archs - the changes are bitness specific, not arch specific. Is
> it OK if I do this?
>
> #ifndef HAVE_ARCH_UNMAPPED_EXEC_AREA
> void *arch_get_unmapped_exec_area(...)
> {
> ...
> }
> #endif
>
Only if this is really an architecture-specific function overridden in
specific architectures. I'm not so sure that applies here.
Furthermore, I'm not even all that sure what this function *does*.
-hpa
WARNING: multiple messages have this Message-ID (diff)
From: "H. Peter Anvin" <hpa@zytor.com>
To: Vasiliy Kulikov <segoon@openwall.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
kernel-hardening@lists.openwall.com,
Peter Zijlstra <peterz@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>,
x86@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [RFC] x86, mm: start mmap allocation for libs from low addresses
Date: Mon, 22 Aug 2011 13:17:47 -0700 [thread overview]
Message-ID: <4E52B96B.8040404@zytor.com> (raw)
In-Reply-To: <20110822201418.GA3176@albatros>
On 08/22/2011 01:14 PM, Vasiliy Kulikov wrote:
>
>> Code-wise:
>>
>> The code is horrific; it is full of open-coded magic numbers;
>
> Agreed, the magic needs macro definition and comments.
>
>> it also
>> puts a function called arch_get_unmapped_exec_area() in a generic file,
>> which could best be described as "WTF" -- the arch_ prefix we use
>> specifically to denote a per-architecture hook function.
>
> Agreed. But I'd want to leave it in mm/mmap.c as it's likely be used by
> other archs - the changes are bitness specific, not arch specific. Is
> it OK if I do this?
>
> #ifndef HAVE_ARCH_UNMAPPED_EXEC_AREA
> void *arch_get_unmapped_exec_area(...)
> {
> ...
> }
> #endif
>
Only if this is really an architecture-specific function overridden in
specific architectures. I'm not so sure that applies here.
Furthermore, I'm not even all that sure what this function *does*.
-hpa
WARNING: multiple messages have this Message-ID (diff)
From: "H. Peter Anvin" <hpa@zytor.com>
To: Vasiliy Kulikov <segoon@openwall.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
kernel-hardening@lists.openwall.com,
Peter Zijlstra <peterz@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>,
x86@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [RFC] x86, mm: start mmap allocation for libs from low addresses
Date: Mon, 22 Aug 2011 13:17:47 -0700 [thread overview]
Message-ID: <4E52B96B.8040404@zytor.com> (raw)
In-Reply-To: <20110822201418.GA3176@albatros>
On 08/22/2011 01:14 PM, Vasiliy Kulikov wrote:
>
>> Code-wise:
>>
>> The code is horrific; it is full of open-coded magic numbers;
>
> Agreed, the magic needs macro definition and comments.
>
>> it also
>> puts a function called arch_get_unmapped_exec_area() in a generic file,
>> which could best be described as "WTF" -- the arch_ prefix we use
>> specifically to denote a per-architecture hook function.
>
> Agreed. But I'd want to leave it in mm/mmap.c as it's likely be used by
> other archs - the changes are bitness specific, not arch specific. Is
> it OK if I do this?
>
> #ifndef HAVE_ARCH_UNMAPPED_EXEC_AREA
> void *arch_get_unmapped_exec_area(...)
> {
> ...
> }
> #endif
>
Only if this is really an architecture-specific function overridden in
specific architectures. I'm not so sure that applies here.
Furthermore, I'm not even all that sure what this function *does*.
-hpa
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next prev parent reply other threads:[~2011-08-22 20:17 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-12 10:29 [kernel-hardening] [RFC] x86, mm: start mmap allocation for libs from low addresses Vasiliy Kulikov
2011-08-12 10:29 ` Vasiliy Kulikov
2011-08-12 10:29 ` Vasiliy Kulikov
2011-08-12 10:58 ` [kernel-hardening] " Solar Designer
2011-08-12 11:05 ` Vasiliy Kulikov
2011-08-25 17:19 ` Vasiliy Kulikov
2011-08-25 17:39 ` Solar Designer
2011-09-02 18:29 ` Solar Designer
2011-09-03 11:18 ` Vasiliy Kulikov
2011-09-03 23:57 ` Solar Designer
2011-09-05 12:46 ` Vasiliy Kulikov
2011-09-06 5:05 ` Solar Designer
2011-09-07 9:09 ` Vasiliy Kulikov
2011-09-07 9:30 ` Solar Designer
2011-09-07 9:34 ` Vasiliy Kulikov
2011-09-07 9:43 ` Solar Designer
2011-09-07 9:55 ` Vasiliy Kulikov
2011-09-07 10:16 ` Solar Designer
2011-09-07 11:01 ` Vasiliy Kulikov
2011-09-02 23:34 ` Solar Designer
2011-09-03 12:12 ` Vasiliy Kulikov
2011-09-03 23:40 ` Solar Designer
2011-09-04 7:21 ` Vasiliy Kulikov
2011-08-12 23:19 ` [kernel-hardening] " H. Peter Anvin
2011-08-12 23:19 ` H. Peter Anvin
2011-08-12 23:19 ` H. Peter Anvin
2011-08-13 6:26 ` [kernel-hardening] " Vasiliy Kulikov
2011-08-13 6:26 ` Vasiliy Kulikov
2011-08-13 6:26 ` Vasiliy Kulikov
2011-08-16 9:05 ` [kernel-hardening] " Vasiliy Kulikov
2011-08-16 9:05 ` Vasiliy Kulikov
2011-08-16 9:05 ` Vasiliy Kulikov
2011-08-22 10:17 ` [kernel-hardening] " Vasiliy Kulikov
2011-08-22 10:17 ` Vasiliy Kulikov
2011-08-22 10:17 ` Vasiliy Kulikov
2011-08-22 17:24 ` [kernel-hardening] " H. Peter Anvin
2011-08-22 17:24 ` H. Peter Anvin
2011-08-22 17:24 ` H. Peter Anvin
2011-08-22 20:14 ` [kernel-hardening] " Vasiliy Kulikov
2011-08-22 20:14 ` Vasiliy Kulikov
2011-08-22 20:14 ` Vasiliy Kulikov
2011-08-22 20:17 ` H. Peter Anvin [this message]
2011-08-22 20:17 ` H. Peter Anvin
2011-08-22 20:17 ` H. Peter Anvin
2011-08-23 6:41 ` [kernel-hardening] " Vasiliy Kulikov
2011-08-23 6:41 ` Vasiliy Kulikov
2011-08-23 6:41 ` Vasiliy Kulikov
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