linux.git/arch/parisc/kernel/sys_parisc.c, branch v3.17

parisc,metag: Do not hardcode maximum userspace stack size

2014-05-14T23:01:41+00:00

This patch affects only architectures where the stack grows upwards
(currently parisc and metag only). On those do not hardcode the maximum
initial stack size to 1GB for 32-bit processes, but make it configurable
via a config option.

The main problem with the hardcoded stack size is, that we have two
memory regions which grow upwards: stack and heap. To keep most of the
memory available for heap in a flexmap memory layout, it makes no sense
to hard allocate up to 1GB of the memory for stack which can't be used
as heap then.

This patch makes the stack size for 32-bit processes configurable and
uses 80MB as default value which has been in use during the last few
years on parisc and which hasn't showed any problems yet.

Signed-off-by: Helge Deller 
Signed-off-by: James Hogan 
Cc: "James E.J. Bottomley" 
Cc: linux-parisc@vger.kernel.org
Cc: linux-metag@vger.kernel.org
Cc: John David Anglin

parisc: change value of SHMLBA from 0x00400000 to PAGE_SIZE

2014-04-13T13:00:53+00:00

On parisc, SHMLBA was defined to 0x00400000 (4MB) to reflect that we need to
take care of our caches for shared mappings. But actually, we can map a file at
any multiple address of PAGE_SIZE, so let us correct that now with a value of
PAGE_SIZE for SHMLBA.  Instead we now take care of this cache colouring via the
constant SHM_COLOUR while we map shared pages.

Signed-off-by: Helge Deller 
CC: Jeroen Roovers 
CC: John David Anglin 
CC: Carlos O'Donell 
Cc: stable@kernel.org [3.13+]

parisc: add flexible mmap memory layout support

2014-02-02T20:00:13+00:00

Add support for the flexible mmap memory layout (as described in
http://lwn.net/Articles/91829). This is especially very interesting on
parisc since we currently only support 32bit userspace (even with a
64bit Linux kernel).

Signed-off-by: Helge Deller

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

2013-11-30T19:57:50+00:00

locale-gen on Debian showed a strange problem on parisc:
mmap2(NULL, 536870912, PROT_NONE, MAP_SHARED, 3, 0) = 0x42a54000
mmap2(0x42a54000, 103860, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, 3, 0) = -1 EINVAL (Invalid argument)

Basically it was just trying to re-mmap() a file at the same address
which it was given by a previous mmap() call. But this remapping failed
with EINVAL.

The problem is, that when MAP_FIXED and MAP_SHARED flags were used, we didn't
included the mapping-based offset when we verified the alignment of the given
fixed address against the offset which we calculated it in the previous call.

Signed-off-by: Helge Deller 
Cc:  # 3.10+

mm: use vm_unmapped_area() on parisc architecture

2013-02-28T03:10:09+00:00

Update the parisc arch_get_unmapped_area function to make use of
vm_unmapped_area() instead of implementing a brute force search.

[akpm@linux-foundation.org: remove now-unused DCACHE_ALIGN(), per James]
Signed-off-by: Michel Lespinasse 
Acked-by: Rik van Riel 
Cc: "James E.J. Bottomley" 
Acked-by: Helge Deller 
Tested-by: Helge Deller 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

parisc: fix fallocate syscall

2013-02-20T21:57:12+00:00

fallocate(off_t) gets redirected by glibc to fallocate64(loff_t)
where the 64bit loff_t values get splitted into two 32bit (hi/lo)
values. This patch fixes this syscall for the 32- and 64bit kernel.

Signed-off-by: Helge Deller

parisc: ensure that mmapped shared pages are aligned at SHMLBA addresses

2013-02-20T21:50:50+00:00

Signed-off-by: John David Anglin 
Signed-off-by: Helge Deller

[PARISC] fix virtual aliasing issue in get_shared_area()

2012-11-15T13:49:34+00:00

On Thu, 2012-11-01 at 16:45 -0700, Michel Lespinasse wrote:
> Looking at the arch/parisc/kernel/sys_parisc.c implementation of
> get_shared_area(), I do have a concern though. The function basically
> ignores the pgoff argument, so that if one creates a shared mapping of
> pages 0-N of a file, and then a separate shared mapping of pages 1-N
> of that same file, both will have the same cache offset for their
> starting address.
>
> This looks like this would create obvious aliasing issues. Am I
> misreading this ? I can't understand how this could work good enough
> to be undetected, so there must be something I'm missing here ???

This turns out to be correct and we need to pay attention to the pgoff as
well as the address when creating the virtual address for the area.
Fortunately, the bug is rarely triggered as most applications which use pgoff
tend to use large values (git being the primary one, and it uses pgoff in
multiples of 16MB) which are larger than our cache coherency modulus, so the
problem isn't often seen in practise.

Reported-by: Michel Lespinasse 
Cc: 
Signed-off-by: James Bottomley

[PARISC] fix personality flag check in copy_thread()

2012-08-03T10:25:12+00:00

Directly comparing task_struct->personality against PER_* is not fully
correct, as it doesn't take flags potentially stored in top three bytes
into account.

Analogically, directly forcefully setting personality to PER_LINUX32 or
PER_LINUX discards any flags stored in the top three bytes.

Signed-off-by: Jiri Kosina 
Signed-off-by: James Bottomley

improve sys_newuname() for compat architectures

2010-03-12T23:52:32+00:00

On an architecture that supports 32-bit compat we need to override the
reported machine in uname with the 32-bit value.  Instead of doing this
separately in every architecture introduce a COMPAT_UTS_MACHINE define in
 and apply it directly in sys_newuname().

Signed-off-by: Christoph Hellwig 
Cc: Ralf Baechle 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mundt 
Cc: Jeff Dike 
Cc: Hirokazu Takata 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: H. Peter Anvin 
Cc: Al Viro 
Cc: Arnd Bergmann 
Cc: Heiko Carstens 
Cc: Martin Schwidefsky 
Cc: "Luck, Tony" 
Cc: James Morris 
Cc: Andreas Schwab 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds