Re: parisc: fix mmap(MAP_FIXED|MAP_SHARED) to already mmapped address

From: Aaro Koskinen <aaro.koskinen@iki.fi>
To: John David Anglin <dave.anglin@bell.net>
Cc: Helge Deller <deller@gmx.de>, linux-parisc@vger.kernel.org
Subject: Re: parisc: fix mmap(MAP_FIXED|MAP_SHARED) to already mmapped address
Date: Thu, 19 Dec 2013 22:28:02 +0200	[thread overview]
Message-ID: <20131219202802.GD2881@blackmetal.musicnaut.iki.fi> (raw)
In-Reply-To: <BLU0-SMTP47556722282C83F98582B797C50@phx.gbl>

Hi,

On Thu, Dec 19, 2013 at 02:44:40PM -0500, John David Anglin wrote:
> On 12/19/2013 2:17 PM, Aaro Koskinen wrote:
> >This commit (0576da2c08e3d332f1b0653030d28ab804585ab6) and the current
> >mainline kernel (3.13-rc4) gives me the following with GLIBC 2.18:
> >
> >$ localedef -c -i en_US -f UTF-8 en_US.UTF-8
> >cannot map archive header: Invalid argument
> >
> >strace looks like this:
> >
> >mmap2(NULL, 536870912, PROT_NONE, MAP_SHARED, 3, 0) = 0x42f34000
> >mmap2(0x43000000, 1607632, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, 3, 0) = -1 EINVAL (Invalid argument)
> >
> >With the patch reverted, it works:
> >
> >mmap2(NULL, 536870912, PROT_NONE, MAP_SHARED, 3, 0) = 0x42d74000
> >mmap2(0x43000000, 1607632, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, 3, 0) = 0x43000000
> >
> >BTW, note that for GLIBC 2.18 some changes were done regarding this:
> >https://sourceware.org/bugzilla/show_bug.cgi?id=10283
> Are you sure the glibc changes are correct?  PARISC addresses are
> not strictly aligned to SHMLBA.

No, I'm not sure. I just wanted to report this issue since I see it on
my box and there is a recent kernel change that seems to be somewhat
related. Of course if the glibc is broken we should try to fix that.

A.