From: John David Anglin <dave.anglin@bell.net>
To: Helge Deller <deller@gmx.de>,
linux-parisc@vger.kernel.org,
James Bottomley <James.Bottomley@hansenpartnership.com>
Subject: Re: [PATCH] parisc: Add MAP_UNINITIALIZED define
Date: Sun, 11 Oct 2020 09:21:35 -0400 [thread overview]
Message-ID: <77faa98f-8e5e-0411-566b-2250aa27e507@bell.net> (raw)
In-Reply-To: <5ac6cd13-de63-c625-88a6-ba736480f79e@gmx.de>
Yes, I believe it only should be nonzero in nommu case.
Dave
On 2020-10-11 7:56 a.m., Helge Deller wrote:
> On 10/10/20 11:54 PM, Helge Deller wrote:
>> Define MAP_UNINITIALIZED and use same value as other architectures.
>> Fixes build of debian foot package.
> I'm tempted to #define MAP_UNINITIALIZED to zero.
> That flag was invented for embedded usage, and becaue of security reasons
> we probably will never deliver uninitialized pages to userspace on parisc.
> So, defining it as 0 should be fine, as this fixes build errors and won't
> have any other (negative) effect.
> Thoughts?
>
> Helge
>
>
>> Suggested-by: John David Anglin <dave.anglin@bell.net>
>> Signed-off-by: Helge Deller <deller@gmx.de>
>>
>> diff --git a/arch/parisc/include/uapi/asm/mman.h b/arch/parisc/include/uapi/asm/mman.h
>> index 6fd8871e4081..d828b293b6de 100644
>> --- a/arch/parisc/include/uapi/asm/mman.h
>> +++ b/arch/parisc/include/uapi/asm/mman.h
>> @@ -25,6 +25,8 @@
>> #define MAP_STACK 0x40000 /* give out an address that is best suited for process/thread stacks */
>> #define MAP_HUGETLB 0x80000 /* create a huge page mapping */
>> #define MAP_FIXED_NOREPLACE 0x100000 /* MAP_FIXED which doesn't unmap underlying mapping */
>> +#define MAP_UNINITIALIZED 0x4000000 /* For anonymous mmap, memory could be
>> + * uninitialized */
>>
>> #define MS_SYNC 1 /* synchronous memory sync */
>> #define MS_ASYNC 2 /* sync memory asynchronously */
>> diff --git a/tools/arch/parisc/include/uapi/asm/mman.h b/tools/arch/parisc/include/uapi/asm/mman.h
>> index f9fd1325f5bd..c7af0f2292fc 100644
>> --- a/tools/arch/parisc/include/uapi/asm/mman.h
>> +++ b/tools/arch/parisc/include/uapi/asm/mman.h
>> @@ -39,6 +39,5 @@
>> #define MADV_SOFT_OFFLINE 101
>> /* MAP_32BIT is undefined on parisc, fix it for perf */
>> #define MAP_32BIT 0
>> -/* MAP_UNINITIALIZED is undefined on parisc, fix it for perf */
>> -#define MAP_UNINITIALIZED 0
>> +#define MAP_UNINITIALIZED 0x4000000
>> #endif
>>
--
John David Anglin dave.anglin@bell.net
next prev parent reply other threads:[~2020-10-11 13:21 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-10 21:54 [PATCH] parisc: Add MAP_UNINITIALIZED define Helge Deller
2020-10-11 11:56 ` Helge Deller
2020-10-11 13:21 ` John David Anglin [this message]
2020-10-12 6:50 ` PATCH v2] " Helge Deller
2020-10-12 8:24 ` Rolf Eike Beer
2020-10-12 8:51 ` Helge Deller
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=77faa98f-8e5e-0411-566b-2250aa27e507@bell.net \
--to=dave.anglin@bell.net \
--cc=James.Bottomley@hansenpartnership.com \
--cc=deller@gmx.de \
--cc=linux-parisc@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).