Граф коммитов

162 Коммитов

Автор SHA1 Сообщение Дата
Stephen Wilson cae5d39032 mm: arch: rename in_gate_area_no_task to in_gate_area_no_mm
Now that gate vma's are referenced with respect to a particular mm and not a
particular task it only makes sense to propagate the change to this predicate as
well.

Signed-off-by: Stephen Wilson <wilsons@start.ca>
Reviewed-by: Michel Lespinasse <walken@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-23 16:36:55 -04:00
Jens Axboe 7eaceaccab block: remove per-queue plugging
Code has been converted over to the new explicit on-stack plugging,
and delay users have been converted to use the new API for that.
So lets kill off the old plugging along with aops->sync_page().

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-10 08:52:07 +01:00
Michel Lespinasse 53a7706d5e mlock: do not hold mmap_sem for extended periods of time
__get_user_pages gets a new 'nonblocking' parameter to signal that the
caller is prepared to re-acquire mmap_sem and retry the operation if
needed.  This is used to split off long operations if they are going to
block on a disk transfer, or when we detect contention on the mmap_sem.

[akpm@linux-foundation.org: remove ref to rwsem_is_contended()]
Signed-off-by: Michel Lespinasse <walken@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13 17:32:36 -08:00
Paul Mundt 29c185e5c6 nommu: Provide stubbed alloc/free_vm_area() implementation.
Now that these have been introduced in to the vmalloc API, sync up the
nommu side of things. At present we don't deal with VMAs as such, so for
the time being these will simply BUG() out. In the future it should be
possible to support this interface by layering on top of the vm_regions.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2010-12-24 12:08:30 +09:00
Paul Mundt 9a14f653df nommu: Fix up vmalloc_node() symbol export regression.
Commit e1ca778 ("mm: add vzalloc() and vzalloc_node() helpers") ended up
accidentally deleting the vmalloc_node() symbol export, resulting in:

"vmalloc_node" [net/core/pktgen.ko] undefined!
"vmalloc_node" [net/netfilter/x_tables.ko] undefined!

regressions.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2010-12-24 11:50:34 +09:00
Steven J. Magnani 04c3496152 nommu: yield CPU while disposing VM
Depending on processor speed, page size, and the amount of memory a
process is allowed to amass, cleanup of a large VM may freeze the system
for many seconds.  This can result in a watchdog timeout.

Make sure other tasks receive some service when cleaning up large VMs.

Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
Cc: Greg Ungerer <gerg@snapgear.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-25 06:50:38 +09:00
Al Viro 120a795da0 audit mmap
Normal syscall audit doesn't catch 5th argument of syscall.  It also
doesn't catch the contents of userland structures pointed to be
syscall argument, so for both old and new mmap(2) ABI it doesn't
record the descriptor we are mapping.  For old one it also misses
flags.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-30 08:45:43 -04:00
Dave Young e1ca7788de mm: add vzalloc() and vzalloc_node() helpers
Add vzalloc() and vzalloc_node() to encapsulate the
vmalloc-then-memset-zero operation.

Use __GFP_ZERO to zero fill the allocated memory.

Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Acked-by: Greg Ungerer <gerg@snapgear.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:10 -07:00
Linus Torvalds 297c5eee37 mm: make the vma list be doubly linked
It's a really simple list, and several of the users want to go backwards
in it to find the previous vma.  So rather than have to look up the
previous entry with 'find_vma_prev()' or something similar, just make it
doubly linked instead.

Tested-by: Ian Campbell <ijc@hellion.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-21 08:49:21 -07:00
David Howells fe622e76fd NOMMU: Remove an extraneous no_printk()
Remove an extraneous no_printk() in mm/nommu.c that got missed when the
function got generalised from several things that used it in commit
12fdff3fc2 ("Add a dummy printk function for the maintenance of unused
printks").

Without this, the following error is observed:

  mm/nommu.c:41: error: conflicting types for 'no_printk'
  include/linux/kernel.h:314: error: previous definition of 'no_printk' was here

Reported-by: Michal Simek <monstr@monstr.eu>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-13 16:55:25 -07:00
Bernd Schmidt 3c7b204547 nommu: allow private mappings of read-only devices
Slightly rearrange the logic that determines capabilities and vm_flags.
Disable BDI_CAP_MAP_DIRECT in all cases if the device can't support the
protections.  Allow private readonly mappings of readonly backing devices.

Signed-off-by: Bernd Schmidt <bernds_cb1@t-online.de>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: David McCullough <davidm@snapgear.com>
Acked-by: Greg Ungerer <gerg@uclinux.org>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-26 08:19:23 -07:00
David Howells e1ee65d859 NOMMU: Fix __get_user_pages() to pin last page on offset buffers
Fix __get_user_pages() to make it pin the last page on a buffer that doesn't
begin at the start of a page, but is a multiple of PAGE_SIZE in size.

The problem is that __get_user_pages() advances the pointer too much when it
iterates to the next page if the page it's currently looking at isn't used from
the first byte.  This can cause the end of a short VMA to be reached
prematurely, resulting in the last page being lost.

Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-25 14:13:27 -07:00
David Howells 7561e8ca0d NOMMU: Revert 'nommu: get_user_pages(): pin last page on non-page-aligned start'
Revert the following patch:

	commit c08c6e1f54
	Author: Steven J. Magnani <steve@digidescorp.com>
	Date:   Fri Mar 5 13:42:24 2010 -0800

	nommu: get_user_pages(): pin last page on non-page-aligned start

As it assumes that the mappings begin at the start of pages - something that
isn't necessarily true on NOMMU systems.  On NOMMU systems, it is possible for
a mapping to only occupy part of the page, and not necessarily touch either end
of it; in fact it's also possible for multiple non-overlapping mappings to
coexist on one page (consider direct mappings of ROMFS files, for example).

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Steven J. Magnani <steve@digidescorp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-25 14:13:26 -07:00
David Howells 3fa30460ea nommu: fix an incorrect comment in the do_mmap_shared_file()
Fix an incorrect comment in the do_mmap_shared_file().  If a mapping is
requested MAP_SHARED, then a private copy cannot be made and still provide
correct semantics.

Signed-off-by: David Howells <dhowells@redhat.com>
Reported-by: Dave Hudson <uclinux@blueteddy.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-24 16:31:20 -07:00
Christoph Hellwig a4679373cf Add generic sys_old_mmap()
Add a generic implementation of the old mmap() syscall, which expects its
argument in a memory block and switch all architectures over to use it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Reviewed-by: H. Peter Anvin <hpa@zytor.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: James Morris <jmorris@namei.org>
Cc: Andreas Schwab <schwab@linux-m68k.org>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Greg Ungerer <gerg@uclinux.org>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-12 15:52:32 -08:00
Steven J. Magnani c08c6e1f54 nommu: get_user_pages(): pin last page on non-page-aligned start
The noMMU version of get_user_pages() fails to pin the last page when the
start address isn't page-aligned.  The patch fixes this in a way that
makes find_extend_vma() congruent to its MMU cousin.

Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-06 11:26:27 -08:00
Rik van Riel 5beb493052 mm: change anon_vma linking to fix multi-process server scalability issue
The old anon_vma code can lead to scalability issues with heavily forking
workloads.  Specifically, each anon_vma will be shared between the parent
process and all its child processes.

In a workload with 1000 child processes and a VMA with 1000 anonymous
pages per process that get COWed, this leads to a system with a million
anonymous pages in the same anon_vma, each of which is mapped in just one
of the 1000 processes.  However, the current rmap code needs to walk them
all, leading to O(N) scanning complexity for each page.

This can result in systems where one CPU is walking the page tables of
1000 processes in page_referenced_one, while all other CPUs are stuck on
the anon_vma lock.  This leads to catastrophic failure for a benchmark
like AIM7, where the total number of processes can reach in the tens of
thousands.  Real workloads are still a factor 10 less process intensive
than AIM7, but they are catching up.

This patch changes the way anon_vmas and VMAs are linked, which allows us
to associate multiple anon_vmas with a VMA.  At fork time, each child
process gets its own anon_vmas, in which its COWed pages will be
instantiated.  The parents' anon_vma is also linked to the VMA, because
non-COWed pages could be present in any of the children.

This reduces rmap scanning complexity to O(1) for the pages of the 1000
child processes, with O(N) complexity for at most 1/N pages in the system.
 This reduces the average scanning cost in heavily forking workloads from
O(N) to 2.

The only real complexity in this patch stems from the fact that linking a
VMA to anon_vmas now involves memory allocations.  This means vma_adjust
can fail, if it needs to attach a VMA to anon_vma structures.  This in
turn means error handling needs to be added to the calling functions.

A second source of complexity is that, because there can be multiple
anon_vmas, the anon_vma linking in vma_adjust can no longer be done under
"the" anon_vma lock.  To prevent the rmap code from walking up an
incomplete VMA, this patch introduces the VM_LOCK_RMAP VMA flag.  This bit
flag uses the same slot as the NOMMU VM_MAPPED_COPY, with an ifdef in mm.h
to make sure it is impossible to compile a kernel that needs both symbolic
values for the same bitflag.

Some test results:

Without the anon_vma changes, when AIM7 hits around 9.7k users (on a test
box with 16GB RAM and not quite enough IO), the system ends up running
>99% in system time, with every CPU on the same anon_vma lock in the
pageout code.

With these changes, AIM7 hits the cross-over point around 29.7k users.
This happens with ~99% IO wait time, there never seems to be any spike in
system time.  The anon_vma lock contention appears to be resolved.

[akpm@linux-foundation.org: cleanups]
Signed-off-by: Rik van Riel <riel@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-06 11:26:26 -08:00
David Howells 7e6608724c nommu: fix shared mmap after truncate shrinkage problems
Fix a problem in NOMMU mmap with ramfs whereby a shared mmap can happen
over the end of a truncation.  The problem is that
ramfs_nommu_check_mappings() checks that the reduced file size against the
VMA tree, but not the vm_region tree.

The following sequence of events can cause the problem:

	fd = open("/tmp/x", O_RDWR|O_TRUNC|O_CREAT, 0600);
	ftruncate(fd, 32 * 1024);
	a = mmap(NULL, 32 * 1024, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
	b = mmap(NULL, 16 * 1024, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
	munmap(a, 32 * 1024);
	ftruncate(fd, 16 * 1024);
	c = mmap(NULL, 32 * 1024, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);

Mapping 'a' creates a vm_region covering 32KB of the file.  Mapping 'b'
sees that the vm_region from 'a' is covering the region it wants and so
shares it, pinning it in memory.

Mapping 'a' then goes away and the file is truncated to the end of VMA
'b'.  However, the region allocated by 'a' is still in effect, and has
_not_ been reduced.

Mapping 'c' is then created, and because there's a vm_region covering the
desired region, get_unmapped_area() is _not_ called to repeat the check,
and the mapping is granted, even though the pages from the latter half of
the mapping have been discarded.

However:

	d = mmap(NULL, 16 * 1024, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);

Mapping 'd' should work, and should end up sharing the region allocated by
'a'.

To deal with this, we shrink the vm_region struct during the truncation,
lest do_mmap_pgoff() take it as licence to share the full region
automatically without calling the get_unmapped_area() file op again.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-16 12:15:40 -08:00
David Howells efc1a3b169 nommu: don't need get_unmapped_area() for NOMMU
get_unmapped_area() is unnecessary for NOMMU as no-one calls it.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-16 12:15:40 -08:00
David Howells 779c10232c nommu: remove a superfluous check of vm_region::vm_usage
In split_vma(), there's no need to check if the VMA being split has a
region that's in use by more than one VMA because:

 (1) The preceding test prohibits splitting of non-anonymous VMAs and regions
     (eg: file or chardev backed VMAs).

 (2) Anonymous regions can't be mapped multiple times because there's no handle
     by which to refer to the already existing region.

 (3) If a VMA has previously been split, then the region backing it has also
     been split into two regions, each of usage 1.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-16 12:15:40 -08:00
David Howells 1e2ae599d3 nommu: struct vm_region's vm_usage count need not be atomic
The vm_usage count field in struct vm_region does not need to be atomic as
it's only even modified whilst nommu_region_sem is write locked.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-16 12:15:40 -08:00
Jie Zhang 7959722b95 NOMMU: Use copy_*_user_page() in access_process_vm()
The MMU code uses the copy_*_user_page() variants in access_process_vm()
rather than copy_*_user() as the former includes an icache flush.  This
is important when doing things like setting software breakpoints with
gdb.  So switch the NOMMU code over to do the same.

This patch makes the reasonable assumption that copy_from_user_page()
won't fail - which is probably fine, as we've checked the VMA from which
we're copying is usable, and the copy is not allowed to cross VMAs.  The
one case where it might go wrong is if the VMA is a device rather than
RAM, and that device returns an error which - in which case rubbish will
be returned rather than EIO.

Signed-off-by: Jie Zhang <jie.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: David McCullough <david_mccullough@mcafee.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-06 18:16:02 -08:00
Mike Frysinger cfe79c00a2 NOMMU: Avoiding duplicate icache flushes of shared maps
When working with FDPIC, there are many shared mappings of read-only
code regions between applications (the C library, applet packages like
busybox, etc.), but the current do_mmap_pgoff() function will issue an
icache flush whenever a VMA is added to an MM instead of only doing it
when the map is initially created.

The flush can instead be done when a region is first mmapped PROT_EXEC.
Note that we may not rely on the first mapping of a region being
executable - it's possible for it to be PROT_READ only, so we have to
remember whether we've flushed the region or not, and then flush the
entire region when a bit of it is made executable.

However, this also affects the brk area.  That will no longer be
executable.  We can mprotect() it to PROT_EXEC on MPU-mode kernels, but
for NOMMU mode kernels, when it increases the brk allocation, making
sys_brk() flush the extra from the icache should suffice.  The brk area
probably isn't used by NOMMU programs since the brk area can only use up
the leavings from the stack allocation, where the stack allocation is
larger than requested.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-06 18:16:02 -08:00
Hugh Dickins 66f0dc481e mm: move sys_mmap_pgoff from util.c
Move sys_mmap_pgoff() from mm/util.c to mm/mmap.c and mm/nommu.c,
where we'd expect to find such code: especially now that it contains
the MAP_HUGETLB handling.  Revert mm/util.c to how it was in 2.6.32.

This patch just ignores MAP_HUGETLB in the nommu case, as in 2.6.32,
whereas 2.6.33-rc2 reported -ENOSYS.  Perhaps validate_mmap_request()
should reject it with -EINVAL?  Add that later if necessary.

Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-30 12:23:27 -08:00
Jie Zhang ea63763959 nommu: fix malloc performance by adding uninitialized flag
The NOMMU code currently clears all anonymous mmapped memory.  While this
is what we want in the default case, all memory allocation from userspace
under NOMMU has to go through this interface, including malloc() which is
allowed to return uninitialized memory.  This can easily be a significant
performance penalty.  So for constrained embedded systems were security is
irrelevant, allow people to avoid clearing memory unnecessarily.

This also alters the ELF-FDPIC binfmt such that it obtains uninitialised
memory for the brk and stack region.

Signed-off-by: Jie Zhang <jie.zhang@analog.com>
Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 08:53:24 -08:00
David Howells 89a8640279 NOMMU: Don't pass NULL pointers to fput() in do_mmap_pgoff()
Don't pass NULL pointers to fput() in the error handling paths of the NOMMU
do_mmap_pgoff() as it can't handle it.

The following can be used as a test program:

	int main() { static long long a[1024 * 1024 * 20] = { 0 }; return a;}

Without the patch, the code oopses in atomic_long_dec_and_test() as called by
fput() after the kernel complains that it can't allocate that big a chunk of
memory.  With the patch, the kernel just complains about the allocation size
and then the program segfaults during execve() as execve() can't complete the
allocation of all the new ELF program segments.

Reported-by: Robin Getz <rgetz@blackfin.uclinux.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Robin Getz <rgetz@blackfin.uclinux.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-31 12:11:37 -07:00
Alexey Dobriyan f0f37e2f77 const: mark struct vm_struct_operations
* mark struct vm_area_struct::vm_ops as const
* mark vm_ops in AGP code

But leave TTM code alone, something is fishy there with global vm_ops
being used.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-27 11:39:25 -07:00
David Howells 06aab5a308 NOMMU: Ignore mmap() address param as it is a hint
Ignore the address parameter given to NOMMU mmap() as it is a hint, rather
than giving an error if it's non-zero.  MAP_FIXED still gets an error.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-24 17:20:29 -07:00
David Howells 645d83c5db NOMMU: Fix MAP_PRIVATE mmap() of objects where the data can be mapped directly
Fix MAP_PRIVATE mmap() of files and devices where the data in the backing store
might be mapped directly.  Use the BDI_CAP_MAP_DIRECT capability flag to govern
whether or not we should be trying to map a file directly.  This can be used to
determine whether or not a region has been filled in at the point where we call
do_mmap_shared() or do_mmap_private().

The BDI_CAP_MAP_DIRECT capability flag is cleared by validate_mmap_request() if
there's any reason we can't use it.  It's also cleared in do_mmap_pgoff() if
f_op->get_unmapped_area() fails.

Without this fix, attempting to run a program from a RomFS image on a
non-mappable MTD partition results in a BUG as the kernel attempts XIP, and
this can be caught in gdb:

Program received signal SIGABRT, Aborted.
0xc005dce8 in add_nommu_region (region=<value optimized out>) at mm/nommu.c:547
(gdb) bt
#0  0xc005dce8 in add_nommu_region (region=<value optimized out>) at mm/nommu.c:547
#1  0xc005f168 in do_mmap_pgoff (file=0xc31a6620, addr=<value optimized out>, len=3808, prot=3, flags=6146, pgoff=0) at mm/nommu.c:1373
#2  0xc00a96b8 in elf_fdpic_map_file (params=0xc33fbbec, file=0xc31a6620, mm=0xc31bef60, what=0xc0213144 "executable") at mm.h:1145
#3  0xc00aa8b4 in load_elf_fdpic_binary (bprm=0xc316cb00, regs=<value optimized out>) at fs/binfmt_elf_fdpic.c:343
#4  0xc006b588 in search_binary_handler (bprm=0x6, regs=0xc33fbce0) at fs/exec.c:1234
#5  0xc006c648 in do_execve (filename=<value optimized out>, argv=0xc3ad14cc, envp=0xc3ad1460, regs=0xc33fbce0) at fs/exec.c:1356
#6  0xc0008cf0 in sys_execve (name=<value optimized out>, argv=0xc3ad14cc, envp=0xc3ad1460) at arch/frv/kernel/process.c:263
#7  0xc00075dc in __syscall_call () at arch/frv/kernel/entry.S:897

Note that this fix does the following commit differently:

	commit a190887b58
	Author: David Howells <dhowells@redhat.com>
	Date:   Sat Sep 5 11:17:07 2009 -0700
	nommu: fix error handling in do_mmap_pgoff()

Reported-by: Graff Yang <graff.yang@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-24 17:18:38 -07:00
npiggin@suse.de 25d9e2d152 truncate: new helpers
Introduce new truncate helpers truncate_pagecache and inode_newsize_ok.
vmtruncate is also consolidated from mm/memory.c and mm/nommu.c and
into mm/truncate.c.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-09-24 08:41:47 -04:00
Hugh Dickins 4266c97a3e nommu: fix two build breakages
My 58fa879e1e "mm: FOLL flags for GUP flags"
broke CONFIG_NOMMU build by forgetting to update nommu.c foll_flags type:

  mm/nommu.c:171: error: conflicting types for `__get_user_pages'
  mm/internal.h:254: error: previous declaration of `__get_user_pages' was here
  make[1]: *** [mm/nommu.o] Error 1

My 03f6462a3a "mm: move highest_memmap_pfn"
broke CONFIG_NOMMU build by forgetting to add a nommu.c highest_memmap_pfn:

  mm/built-in.o: In function `memmap_init_zone':
  (.meminit.text+0x326): undefined reference to `highest_memmap_pfn'
  mm/built-in.o: In function `memmap_init_zone':
  (.meminit.text+0x32d): undefined reference to `highest_memmap_pfn'

Fix both breakages, and give myself 30 lashes (ouch!)

Reported-by: Michal Simek <michal.simek@petalogix.com>
Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-23 09:22:10 -07:00
Bernd Schmidt eb8cdec4a9 nommu: add support for Memory Protection Units (MPU)
Some architectures (like the Blackfin arch) implement some of the
"simpler" features that one would expect out of a MMU such as memory
protection.

In our case, we actually get read/write/exec protection down to the page
boundary so processes can't stomp on each other let alone the kernel.

There is a performance decrease (which depends greatly on the workload)
however as the hardware/software interaction was not optimized at design
time.

Signed-off-by: Bernd Schmidt <bernds_cb1@t-online.de>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-22 07:17:43 -07:00
Hugh Dickins 58fa879e1e mm: FOLL flags for GUP flags
__get_user_pages() has been taking its own GUP flags, then processing
them into FOLL flags for follow_page().  Though oddly named, the FOLL
flags are more widely used, so pass them to __get_user_pages() now.
Sorry, VM flags, VM_FAULT flags and FAULT_FLAGs are still distinct.

(The patch to __get_user_pages() looks peculiar, with both gup_flags
and foll_flags: the gup_flags remain constant; but as before there's
an exceptional case, out of scope of the patch, in which foll_flags
per page have FOLL_WRITE masked off.)

Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Rik van Riel <riel@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-22 07:17:40 -07:00
Hugh Dickins 1c3aff1cee mm: remove unused GUP flags
GUP_FLAGS_IGNORE_VMA_PERMISSIONS and GUP_FLAGS_IGNORE_SIGKILL were
flags added solely to prevent __get_user_pages() from doing some of
what it usually does, in the munlock case: we can now remove them.

Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-22 07:17:40 -07:00
Jaswinder Singh Rajput 72ff13b703 mm: includecheck fix for mm/nommu.c
Fix the following 'make includecheck' warning:

  mm/nommu.c: internal.h is included more than once.

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Acked-by: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-22 07:17:35 -07:00
David Howells a190887b58 nommu: fix error handling in do_mmap_pgoff()
Fix the error handling in do_mmap_pgoff().  If do_mmap_shared_file() or
do_mmap_private() fail, we jump to the error_put_region label at which
point we cann __put_nommu_region() on the region - but we haven't yet
added the region to the tree, and so __put_nommu_region() may BUG
because the region tree is empty or it may corrupt the region tree.

To get around this, we can afford to add the region to the region tree
before calling do_mmap_shared_file() or do_mmap_private() as we keep
nommu_region_sem write-locked, so no-one can race with us by seeing a
transient region.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Acked-by: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-05 11:30:42 -07:00
Graff Yang 28d7a6ae92 nommu: check fd read permission in validate_mmap_request()
According to the POSIX (1003.1-2008), the file descriptor shall have been
opened with read permission, regardless of the protection options specified to
mmap().  The ltp test cases mmap06/07 need this.

Signed-off-by: Graff Yang <graff.yang@gmail.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-08-18 16:31:13 -07:00
Eric Paris 788084aba2 Security/SELinux: seperate lsm specific mmap_min_addr
Currently SELinux enforcement of controls on the ability to map low memory
is determined by the mmap_min_addr tunable.  This patch causes SELinux to
ignore the tunable and instead use a seperate Kconfig option specific to how
much space the LSM should protect.

The tunable will now only control the need for CAP_SYS_RAWIO and SELinux
permissions will always protect the amount of low memory designated by
CONFIG_LSM_MMAP_MIN_ADDR.

This allows users who need to disable the mmap_min_addr controls (usual reason
being they run WINE as a non-root user) to do so and still have SELinux
controls preventing confined domains (like a web server) from being able to
map some area of low memory.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-08-17 15:09:11 +10:00
Linus Torvalds 5a475ce469 Merge git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6:
  sh: LCDC dcache flush for deferred io
  sh: Fix compiler error and include the definition of IS_ERR_VALUE
  sh: re-add LCDC fbdev support to the Migo-R defconfig
  sh: fix se7724 ceu names
  sh: ms7724se: Enable sh_eth in defconfig.
  arch/sh/boards/mach-se/7206/io.c: Remove unnecessary semicolons
  sh: ms7724se: Add sh_eth support
  nommu: provide follow_pfn().
  sh: Kill off unused DEBUG_BOOTMEM symbol.
  perf_counter tools: add cpu_relax()/rmb() definitions for sh.
  sh64: Hook up page fault events for software perf counters.
  sh: Hook up page fault events for software perf counters.
  sh: make set_perf_counter_pending() static inline.
  clocksource: sh_tmu: Make undefined TCOR behaviour less undefined.
2009-07-01 11:46:30 -07:00
Paul Mundt dfc2f91ac2 nommu: provide follow_pfn().
With the introduction of follow_pfn() as an exported symbol, modules have
begun making use of it. Unfortunately this was not reflected on nommu at
the time, so the in-tree users have subsequently all blown up with link
errors there.

This provides a simple follow_pfn() that just returns addr >> PAGE_SHIFT,
which will do the right thing on nommu. There is no need to do range
checking within the vma, as the find_vma() case will already take care of
this.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-06-26 04:31:57 +09:00
Peter Zijlstra 9d73777e50 clarify get_user_pages() prototype
Currently the 4th parameter of get_user_pages() is called len, but its
in pages, not bytes. Rename the thing to nr_pages to avoid future
confusion.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-25 11:22:13 -07:00
Paul Mundt 35f2c2f6f6 nommu: Provide mmap_min_addr definition.
With the "security: use mmap_min_addr indepedently of security models"
change, mmap_min_addr is used in common areas, which susbsequently blows
up the nommu build. This stubs in the definition in the nommu case as
well.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

--

 mm/nommu.c |    3 +++
 1 file changed, 3 insertions(+)
Signed-off-by: James Morris <jmorris@namei.org>
2009-06-10 09:24:09 +10:00
David Howells 8c9ed899b4 NOMMU: Don't check vm_region::vm_start is page aligned in add_nommu_region()
Don't check vm_region::vm_start is page aligned in add_nommu_region() because
the region may reflect some non-page-aligned mapped file, such as could be
obtained from RomFS XIP.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-07 12:03:41 -07:00
David Howells fc4d5c292b nommu: make the initial mmap allocation excess behaviour Kconfig configurable
NOMMU mmap() has an option controlled by a sysctl variable that determines
whether the allocations made by do_mmap_private() should have the excess
space trimmed off and returned to the allocator.  Make the initial setting
of this variable a Kconfig configuration option.

The reason there can be excess space is that the allocator only allocates
in power-of-2 size chunks, but mmap()'s can be made in sizes that aren't a
power of 2.

There are two alternatives:

 (1) Keep the excess as dead space.  The dead space then remains unused for the
     lifetime of the mapping.  Mappings of shared objects such as libc, ld.so
     or busybox's text segment may retain their dead space forever.

 (2) Return the excess to the allocator.  This means that the dead space is
     limited to less than a page per mapping, but it means that for a transient
     process, there's more chance of fragmentation as the excess space may be
     reused fairly quickly.

During the boot process, a lot of transient processes are created, and
this can cause a lot of fragmentation as the pagecache and various slabs
grow greatly during this time.

By turning off the trimming of excess space during boot and disabling
batching of frees, Coldfire can manage to boot.

A better way of doing things might be to have /sbin/init turn this option
off.  By that point libc, ld.so and init - which are all long-duration
processes - have all been loaded and trimmed.

Reported-by: Lanttor Guo <lanttor.guo@freescale.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Lanttor Guo <lanttor.guo@freescale.com>
Cc: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-06 16:36:10 -07:00
KOSAKI Motohiro 00a62ce91e mm: fix Committed_AS underflow on large NR_CPUS environment
The Committed_AS field can underflow in certain situations:

>         # while true; do cat /proc/meminfo  | grep _AS; sleep 1; done | uniq -c
>               1 Committed_AS: 18446744073709323392 kB
>              11 Committed_AS: 18446744073709455488 kB
>               6 Committed_AS:    35136 kB
>               5 Committed_AS: 18446744073709454400 kB
>               7 Committed_AS:    35904 kB
>               3 Committed_AS: 18446744073709453248 kB
>               2 Committed_AS:    34752 kB
>               9 Committed_AS: 18446744073709453248 kB
>               8 Committed_AS:    34752 kB
>               3 Committed_AS: 18446744073709320960 kB
>               7 Committed_AS: 18446744073709454080 kB
>               3 Committed_AS: 18446744073709320960 kB
>               5 Committed_AS: 18446744073709454080 kB
>               6 Committed_AS: 18446744073709320960 kB

Because NR_CPUS can be greater than 1000 and meminfo_proc_show() does
not check for underflow.

But NR_CPUS proportional isn't good calculation.  In general,
possibility of lock contention is proportional to the number of online
cpus, not theorical maximum cpus (NR_CPUS).

The current kernel has generic percpu-counter stuff.  using it is right
way.  it makes code simplify and percpu_counter_read_positive() don't
make underflow issue.

Reported-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Eric B Munson <ebmunson@us.ibm.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: <stable@kernel.org>		[All kernel versions]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-02 15:36:10 -07:00
David Howells 33e5d76979 nommu: fix a number of issues with the per-MM VMA patch
Fix a number of issues with the per-MM VMA patch:

 (1) Make mmap_pages_allocated an atomic_long_t, just in case this is used on
     a NOMMU system with more than 2G pages.  Makes no difference on a 32-bit
     system.

 (2) Report vma->vm_pgoff * PAGE_SIZE as a 64-bit value, not a 32-bit value,
     lest it overflow.

 (3) Move the allocation of the vm_area_struct slab back for fork.c.

 (4) Use KMEM_CACHE() for both vm_area_struct and vm_region slabs.

 (5) Use BUG_ON() rather than if () BUG().

 (6) Make the default validate_nommu_regions() a static inline rather than a
     #define.

 (7) Make free_page_series()'s objection to pages with a refcount != 1 more
     informative.

 (8) Adjust the __put_nommu_region() banner comment to indicate that the
     semaphore must be held for writing.

 (9) Limit the number of warnings about munmaps of non-mmapped regions.

Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02 19:04:48 -07:00
Greg Ungerer 05ae6fa318 uclinux: add process name to allocation error message
This patch adds the name of the process to the bad allocation error
message on non-MMU systems.

Changed suggested by jsujjavanich@syntech-fuelmaster.com

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
2009-01-27 16:42:03 +10:00
Paul Mundt eb6434d9e7 nommu: Stub in vm_map_ram()/vm_unmap_ram()/vm_unmap_aliases().
Presently we do not support these interfaces, so make them BUG() wrappers
as per the rest of the vmap interface on nommu. Fixes up the modular xfs
build.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-01-21 17:45:47 +09:00
Heiko Carstens 6a6160a7b5 [CVE-2009-0029] System call wrappers part 13
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:23 +01:00
Heiko Carstens 2ed7c03ec1 [CVE-2009-0029] Convert all system calls to return a long
Convert all system calls to return a long. This should be a NOP since all
converted types should have the same size anyway.
With the exception of sys_exit_group which returned void. But that doesn't
matter since the system call doesn't return.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:14 +01:00
Paul Mundt ab2e83ead4 NOMMU: Teach kobjsize() about VMA regions.
Now that we no longer use compound pages for all large allocations,
kobjsize() actively breaks things like binfmt_flat by always handing
back PAGE_SIZE for mmap'ed regions. Fix this up by looking up the
VMA region for non-compounds.

Ideally binfmt_flat wants to get rid of kobjsize() completely, but
this is an incremental step.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Mike Frysinger <vapier.adi@gmail.com>
2009-01-08 12:04:48 +00:00
Paul Mundt dd8632a12e NOMMU: Make mmap allocation page trimming behaviour configurable.
NOMMU mmap allocates a piece of memory for an mmap that's rounded up in size to
the nearest power-of-2 number of pages.  Currently it then discards the excess
pages back to the page allocator, making that memory available for use by other
things.  This can, however, cause greater amount of fragmentation.

To counter this, a sysctl is added in order to fine-tune the trimming
behaviour.  The default behaviour remains to trim pages aggressively, while
this can either be disabled completely or set to a higher page-granular
watermark in order to have finer-grained control.

vm region vm_top bits taken from an earlier patch by David Howells.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Mike Frysinger <vapier.adi@gmail.com>
2009-01-08 12:04:47 +00:00
David Howells 8feae13110 NOMMU: Make VMAs per MM as for MMU-mode linux
Make VMAs per mm_struct as for MMU-mode linux.  This solves two problems:

 (1) In SYSV SHM where nattch for a segment does not reflect the number of
     shmat's (and forks) done.

 (2) In mmap() where the VMA's vm_mm is set to point to the parent mm by an
     exec'ing process when VM_EXECUTABLE is specified, regardless of the fact
     that a VMA might be shared and already have its vm_mm assigned to another
     process or a dead process.

A new struct (vm_region) is introduced to track a mapped region and to remember
the circumstances under which it may be shared and the vm_list_struct structure
is discarded as it's no longer required.

This patch makes the following additional changes:

 (1) Regions are now allocated with alloc_pages() rather than kmalloc() and
     with no recourse to __GFP_COMP, so the pages are not composite.  Instead,
     each page has a reference on it held by the region.  Anything else that is
     interested in such a page will have to get a reference on it to retain it.
     When the pages are released due to unmapping, each page is passed to
     put_page() and will be freed when the page usage count reaches zero.

 (2) Excess pages are trimmed after an allocation as the allocation must be
     made as a power-of-2 quantity of pages.

 (3) VMAs are added to the parent MM's R/B tree and mmap lists.  As an MM may
     end up with overlapping VMAs within the tree, the VMA struct address is
     appended to the sort key.

 (4) Non-anonymous VMAs are now added to the backing inode's prio list.

 (5) Holes may be punched in anonymous VMAs with munmap(), releasing parts of
     the backing region.  The VMA and region structs will be split if
     necessary.

 (6) sys_shmdt() only releases one attachment to a SYSV IPC shared memory
     segment instead of all the attachments at that addresss.  Multiple
     shmat()'s return the same address under NOMMU-mode instead of different
     virtual addresses as under MMU-mode.

 (7) Core dumping for ELF-FDPIC requires fewer exceptions for NOMMU-mode.

 (8) /proc/maps is now the global list of mapped regions, and may list bits
     that aren't actually mapped anywhere.

 (9) /proc/meminfo gains a line (tagged "MmapCopy") that indicates the amount
     of RAM currently allocated by mmap to hold mappable regions that can't be
     mapped directly.  These are copies of the backing device or file if not
     anonymous.

These changes make NOMMU mode more similar to MMU mode.  The downside is that
NOMMU mode requires some extra memory to track things over NOMMU without this
patch (VMAs are no longer shared, and there are now region structs).

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Mike Frysinger <vapier.adi@gmail.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
2009-01-08 12:04:47 +00:00
David Howells 41836382eb NOMMU: Delete askedalloc and realalloc variables
Delete the askedalloc and realalloc variables as nothing actually uses the
value calculated.

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Mike Frysinger <vapier.adi@gmail.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
2009-01-08 12:04:47 +00:00
Al Viro acfa4380ef inode->i_op is never NULL
We used to have rather schizophrenic set of checks for NULL ->i_op even
though it had been eliminated years ago.  You'd need to go out of your
way to set it to NULL explicitly _and_ a bunch of code would die on
such inodes anyway.  After killing two remaining places that still
did that bogosity, all that crap can go away.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-01-05 11:54:28 -05:00
Alan Cox 731572d39f nfsd: fix vm overcommit crash
Junjiro R.  Okajima reported a problem where knfsd crashes if you are
using it to export shmemfs objects and run strict overcommit.  In this
situation the current->mm based modifier to the overcommit goes through a
NULL pointer.

We could simply check for NULL and skip the modifier but we've caught
other real bugs in the past from mm being NULL here - cases where we did
need a valid mm set up (eg the exec bug about a year ago).

To preserve the checks and get the logic we want shuffle the checking
around and add a new helper to the vm_ security wrappers

Also fix a current->mm reference in nommu that should use the passed mm

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix build]
Reported-by: Junjiro R. Okajima <hooanon05@yahoo.co.jp>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-30 11:38:47 -07:00
Nick Piggin b291f00039 mlock: mlocked pages are unevictable
Make sure that mlocked pages also live on the unevictable LRU, so kswapd
will not scan them over and over again.

This is achieved through various strategies:

1) add yet another page flag--PG_mlocked--to indicate that
   the page is locked for efficient testing in vmscan and,
   optionally, fault path.  This allows early culling of
   unevictable pages, preventing them from getting to
   page_referenced()/try_to_unmap().  Also allows separate
   accounting of mlock'd pages, as Nick's original patch
   did.

   Note:  Nick's original mlock patch used a PG_mlocked
   flag.  I had removed this in favor of the PG_unevictable
   flag + an mlock_count [new page struct member].  I
   restored the PG_mlocked flag to eliminate the new
   count field.

2) add the mlock/unevictable infrastructure to mm/mlock.c,
   with internal APIs in mm/internal.h.  This is a rework
   of Nick's original patch to these files, taking into
   account that mlocked pages are now kept on unevictable
   LRU list.

3) update vmscan.c:page_evictable() to check PageMlocked()
   and, if vma passed in, the vm_flags.  Note that the vma
   will only be passed in for new pages in the fault path;
   and then only if the "cull unevictable pages in fault
   path" patch is included.

4) add try_to_unlock() to rmap.c to walk a page's rmap and
   ClearPageMlocked() if no other vmas have it mlocked.
   Reuses as much of try_to_unmap() as possible.  This
   effectively replaces the use of one of the lru list links
   as an mlock count.  If this mechanism let's pages in mlocked
   vmas leak through w/o PG_mlocked set [I don't know that it
   does], we should catch them later in try_to_unmap().  One
   hopes this will be rare, as it will be relatively expensive.

Original mm/internal.h, mm/rmap.c and mm/mlock.c changes:
Signed-off-by: Nick Piggin <npiggin@suse.de>

splitlru: introduce __get_user_pages():

  New munlock processing need to GUP_FLAGS_IGNORE_VMA_PERMISSIONS.
  because current get_user_pages() can't grab PROT_NONE pages theresore it
  cause PROT_NONE pages can't munlock.

[akpm@linux-foundation.org: fix this for pagemap-pass-mm-into-pagewalkers.patch]
[akpm@linux-foundation.org: untangle patch interdependencies]
[akpm@linux-foundation.org: fix things after out-of-order merging]
[hugh@veritas.com: fix page-flags mess]
[lee.schermerhorn@hp.com: fix munlock page table walk - now requires 'mm']
[kosaki.motohiro@jp.fujitsu.com: build fix]
[kosaki.motohiro@jp.fujitsu.com: fix truncate race and sevaral comments]
[kosaki.motohiro@jp.fujitsu.com: splitlru: introduce __get_user_pages()]
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-20 08:52:30 -07:00
Paul Mundt 1af446edfe nommu: Provide vmalloc_exec().
Now that SH has switched to vmalloc_exec() for PAGE_KERNEL_EXEC usage,
it's apparent that nommu has no vmalloc_exec() definition of its own.
Stub in the one from mm/vmalloc.c.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-08-04 16:01:47 +09:00
Roland McGrath fa8e26ccd4 tracehook: tracehook_expect_breakpoints
This adds tracehook_expect_breakpoints() as a formal hook for the nommu
code to use for its, "Is text-poking likely?" check at mmap time.  This
names the actual semantics the code means to test, and documents it.

Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 12:00:09 -07:00
Paul Mundt 5a1603be58 nommu: Correct kobjsize() page validity checks.
This implements a few changes on top of the recent kobjsize() refactoring
introduced by commit 6cfd53fc03.

As Christoph points out:

	virt_to_head_page cannot return NULL. virt_to_page also
	does not return NULL. pfn_valid() needs to be used to
	figure out if a page is valid.  Otherwise the page struct
	reference that was returned may have PageReserved() set
	to indicate that it is not a valid page.

As discussed further in the thread, virt_addr_valid() is the preferable
way to validate the object pointer in this case. In addition to fixing
up the reserved page case, it also has the benefit of encapsulating the
hack introduced by commit 4016a1390d on
the impacted platforms, allowing us to get rid of the extra checking in
kobjsize() for the platforms that don't perform this type of bizarre
memory_end abuse (every nommu platform that isn't blackfin). If blackfin
decides to get in line with every other platform and use PageReserved
for the DMA pages in question, kobjsize() will also continue to work
fine.

It also turns out that compound_order() will give us back 0-order for
non-head pages, so we can get rid of the PageCompound check and just
use compound_order() directly. Clean that up while we're at it.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Reviewed-by: Christoph Lameter <clameter@sgi.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-12 07:56:17 -07:00
Paul Mundt 6cfd53fc03 nommu: fix kobjsize() for SLOB and SLUB
kobjsize() has been abusing page->index as a method for sorting out
compound order, which blows up both for page cache pages, and SLOB's
reuse of the index in struct slob_page.

Presently we are not able to accurately size arbitrary pointers that
don't come from kmalloc(), so the best we can do is sort out the
compound order from the head page if it's a compound page, or default
to 0-order if it's impossible to ksize() the object.

Obviously this leaves quite a bit to be desired in terms of object
sizing accuracy, but the behaviour is unchanged over the existing
implementation, while fixing the page->index oopses originally reported
here:

	http://marc.info/?l=linux-mm&m=121127773325245&w=2

Accuracy could also be improved by having SLUB and SLOB both set PG_slab
on ksizeable pages, rather than just handling the __GFP_COMP cases
irregardless of the PG_slab setting, as made possibly with Pekka's
patches:

	http://marc.info/?l=linux-kernel&m=121139439900534&w=2
	http://marc.info/?l=linux-kernel&m=121139440000537&w=2
	http://marc.info/?l=linux-kernel&m=121139440000540&w=2

This is primarily a bugfix for nommu systems for 2.6.26, with the aim
being to gradually kill off kobjsize() and its particular brand of
object abuse entirely.

Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-06 11:29:09 -07:00
Alan Cox 80119ef5c8 mm: fix atomic_t overflow in vm
The atomic_t type is 32bit but a 64bit system can have more than 2^32
pages of virtual address space available.  Without this we overflow on
ludicrously large mappings

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-24 09:56:09 -07:00
Matt Helsley 925d1c401f procfs task exe symlink
The kernel implements readlink of /proc/pid/exe by getting the file from
the first executable VMA.  Then the path to the file is reconstructed and
reported as the result.

Because of the VMA walk the code is slightly different on nommu systems.
This patch avoids separate /proc/pid/exe code on nommu systems.  Instead of
walking the VMAs to find the first executable file-backed VMA we store a
reference to the exec'd file in the mm_struct.

That reference would prevent the filesystem holding the executable file
from being unmounted even after unmapping the VMAs.  So we track the number
of VM_EXECUTABLE VMAs and drop the new reference when the last one is
unmapped.  This avoids pinning the mounted filesystem.

[akpm@linux-foundation.org: improve comments]
[yamamoto@valinux.co.jp: fix dup_mmap]
Signed-off-by: Matt Helsley <matthltc@us.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: David Howells <dhowells@redhat.com>
Cc:"Eric W. Biederman" <ebiederm@xmission.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:17 -07:00
Michael Hennerich 4016a1390d mm/nommu.c: return 0 from kobjsize with invalid objects
Don't perform kobjsize operations on objects the kernel doesn't manage.

On Blackfin, drivers can get dma coherent memory by calling a function
dma_alloc_coherent(). We do this in nommu by configuring a chunk of uncached
memory at the top of memory.

Since we don't want the kernel to use the uncached memory, we lie to the
kernel, and tell it that it's max memory is between 0, and the start of the
uncached dma coherent section.

this all works well, until this memory gets exposed into userspace (with a
frame buffer), when you look at the process's maps, it shows the framebuf:

root:/proc> cat maps
[snip]
03f0ef00-03f34700 rw-p 00000000 1f:00 192        /dev/fb0
root:/proc>

This is outside the "normal" range for the kernel. When the kernel tries to
find the size of this object (when you run ps), it dies in nommu.c in
kobjsize.

BUG_ON(page->index >= MAX_ORDER);

since the page we are referring to is outside what the kernel thinks is it's
max valid memory.

root:~> while [ 1 ]; ps > /dev/null; done
kernel BUG at mm/nommu.c:119!
Kernel panic - not syncing: BUG!

We fixed this by adding a check to reject out of range object pointers as it
already does that for NULL pointers.

Signed-off-by: Michael Hennerich <Michael.Hennerich@analog.com>
Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:26 -07:00
Paul Mundt f905bc447c nommu: add new vmalloc_user() and remap_vmalloc_range() interfaces.
This builds on top of the earlier vmalloc_32_user() work introduced by
b50731732f, as we now have places in the nommu
allmodconfig that hit up against these missing APIs.

As vmalloc_32_user() is already implemented, this is moved over to
vmalloc_user() and simply made a wrapper.  As all current nommu platforms are
32-bit addressable, there's no special casing we have to do for ZONE_DMA and
things of that nature as per GFP_VMALLOC32.

remap_vmalloc_range() needs to check VM_USERMAP in order to figure out whether
we permit the remap or not, which means that we also have to rework the
vmalloc_user() code to grovel for the VMA and set the flag.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: David McCullough <david_mccullough@securecomputing.com>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05 09:44:21 -08:00
Christoph Lameter b3bdda02aa vmalloc: add const to void* parameters
Make vmalloc functions work the same way as kfree() and friends that
take a const void * argument.

[akpm@linux-foundation.org: fix consts, coding-style]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05 09:44:14 -08:00
Eric Paris 7cd94146cd Security: round mmap hint address above mmap_min_addr
If mmap_min_addr is set and a process attempts to mmap (not fixed) with a
non-null hint address less than mmap_min_addr the mapping will fail the
security checks.  Since this is just a hint address this patch will round
such a hint address above mmap_min_addr.

gcj was found to try to be very frugal with vm usage and give hint addresses
in the 8k-32k range.  Without this patch all such programs failed and with
the patch they happily get a higher address.

This patch is wrappad in CONFIG_SECURITY since mmap_min_addr doesn't exist
without it and there would be no security check possible no matter what.  So
we should not bother compiling in this rounding if it is just a waste of
time.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2007-12-06 00:25:10 +11:00
David Howells f2b8544f5f NOMMU: mm/nommu.c needs linux/module.h
mm/nommu.c needs to #include linux/module.h for it to understand EXPORT_*()
macros.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-29 07:53:26 -07:00
Robert P. J. Day 8518609dee Explain clearly why kmalloc() can't use __GFP_HIGHMEM.
Fix the wishy-washy comment to clearly explain why kmalloc() can't
use the __GFP_HIGHMEM zone modifier.

Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
2007-10-19 23:11:38 +02:00
Adrian Bunk cbfee34520 security/ cleanups
This patch contains the following cleanups that are now possible:
- remove the unused security_operations->inode_xattr_getsuffix
- remove the no longer used security_operations->unregister_security
- remove some no longer required exit code
- remove a bunch of no longer used exports

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Acked-by: James Morris <jmorris@namei.org>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17 08:43:07 -07:00
Alan Cox 34b4e4aa3c fix NULL pointer dereference in __vm_enough_memory()
The new exec code inserts an accounted vma into an mm struct which is not
current->mm.  The existing memory check code has a hard coded assumption
that this does not happen as does the security code.

As the correct mm is known we pass the mm to the security method and the
helper function.  A new security test is added for the case where we need
to pass the mm and the existing one is modified to pass current->mm to
avoid the need to change large amounts of code.

(Thanks to Tobias for fixing rejects and testing)

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: WU Fengguang <wfg@mail.ustc.edu.cn>
Cc: James Morris <jmorris@redhat.com>
Cc: Tobias Diedrich <ranma+kernel@tdiedrich.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-22 19:52:45 -07:00
Paul Mundt b50731732f nommu: vmalloc_32_user()/vm_insert_page() and symbol exports.
Trying to survive an allmodconfig on a nommu platform results in many
screen lengths of module unhappiness.  Many of the mmap related things that
binfmt_flat hooks in to are never exported despite being global, and there
are also missing definitions for vmalloc_32_user() and vm_insert_page().

I've implemented vmalloc_32_user() trying to stick as close to the
mm/vmalloc.c implementation as possible, though we don't have any need for
VM_USERMAP, so groveling for the VMA can be skipped.  vm_insert_page() has
been stubbed for now in order to keep the build happy.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-21 17:49:14 -07:00
Nick Piggin d0217ac04c mm: fault feedback #1
Change ->fault prototype.  We now return an int, which contains
VM_FAULT_xxx code in the low byte, and FAULT_RET_xxx code in the next byte.
 FAULT_RET_ code tells the VM whether a page was found, whether it has been
locked, and potentially other things.  This is not quite the way he wanted
it yet, but that's changed in the next patch (which requires changes to
arch code).

This means we no longer set VM_CAN_INVALIDATE in the vma in order to say
that a page is locked which requires filemap_nopage to go away (because we
can no longer remain backward compatible without that flag), but we were
going to do that anyway.

struct fault_data is renamed to struct vm_fault as Linus asked. address
is now a void __user * that we should firmly encourage drivers not to use
without really good reason.

The page is now returned via a page pointer in the vm_fault struct.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:41 -07:00
Nick Piggin 54cb8821de mm: merge populate and nopage into fault (fixes nonlinear)
Nonlinear mappings are (AFAIKS) simply a virtual memory concept that encodes
the virtual address -> file offset differently from linear mappings.

->populate is a layering violation because the filesystem/pagecache code
should need to know anything about the virtual memory mapping.  The hitch here
is that the ->nopage handler didn't pass down enough information (ie.  pgoff).
 But it is more logical to pass pgoff rather than have the ->nopage function
calculate it itself anyway (because that's a similar layering violation).

Having the populate handler install the pte itself is likewise a nasty thing
to be doing.

This patch introduces a new fault handler that replaces ->nopage and
->populate and (later) ->nopfn.  Most of the old mechanism is still in place
so there is a lot of duplication and nice cleanups that can be removed if
everyone switches over.

The rationale for doing this in the first place is that nonlinear mappings are
subject to the pagefault vs invalidate/truncate race too, and it seemed stupid
to duplicate the synchronisation logic rather than just consolidate the two.

After this patch, MAP_NONBLOCK no longer sets up ptes for pages present in
pagecache.  Seems like a fringe functionality anyway.

NOPAGE_REFAULT is removed.  This should be implemented with ->fault, and no
users have hit mainline yet.

[akpm@linux-foundation.org: cleanup]
[randy.dunlap@oracle.com: doc. fixes for readahead]
[akpm@linux-foundation.org: build fix]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 10:04:41 -07:00
Greg Ungerer 57c8f63e8e nommu: stub expand_stack() for nommu case
Be consistent with VM mmap, implement expand_stack().  We can't actually do
anything other than return an error in the no MMU case though.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:37 -07:00
Eric Paris ed03218951 security: Protection for exploiting null dereference using mmap
Add a new security check on mmap operations to see if the user is attempting
to mmap to low area of the address space.  The amount of space protected is
indicated by the new proc tunable /proc/sys/vm/mmap_min_addr and defaults to
0, preserving existing behavior.

This patch uses a new SELinux security class "memprotect."  Policy already
contains a number of allow rules like a_t self:process * (unconfined_t being
one of them) which mean that putting this check in the process class (its
best current fit) would make it useless as all user processes, which we also
want to protect against, would be allowed. By taking the memprotect name of
the new class it will also make it possible for us to move some of the other
memory protect permissions out of 'process' and into the new class next time
we bump the policy version number (which I also think is a good future idea)

Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2007-07-11 22:52:29 -04:00
Christoph Hellwig 1eeb66a1bb move die notifier handling to common code
This patch moves the die notifier handling to common code.  Previous
various architectures had exactly the same code for it.  Note that the new
code is compiled unconditionally, this should be understood as an appel to
the other architecture maintainer to implement support for it aswell (aka
sprinkling a notify_die or two in the proper place)

arm had a notifiy_die that did something totally different, I renamed it to
arm_notify_die as part of the patch and made it static to the file it's
declared and used at.  avr32 used to pass slightly less information through
this interface and I brought it into line with the other architectures.

[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: fix vmalloc_sync_all bustage]
[bryan.wu@analog.com: fix vmalloc_sync_all in nommu]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: <linux-arch@vger.kernel.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 11:15:04 -07:00
Wu, Bryan 6a04de6dbe [PATCH] nommu: fix bug ip_conntrack does not work on nommu
num_physpages is not exported out in mm/nommu.c, so the ip_conntrack module
link will fail.

Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Acked-By: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-04-12 15:31:42 -07:00
David Howells 165b239270 [PATCH] NOMMU: make SYSV SHM nattch work correctly
Make the SYSV SHM nattch counter work correctly by forcing multiple VMAs to
be produced to represent MAP_SHARED segments, even if they overlap exactly.

Using this test program:

	http://people.redhat.com/~dhowells/doshm.c

Run as:

	doshm sysv

I can see nattch going from one before the patch:

	# /doshm sysv
	Command: sysv
	shmid: 65536
	memory: 0xc3700000
	c0b00000-c0b04000 rw-p 00000000 00:00 0
	c0bb0000-c0bba788 r-xs 00000000 00:0b 14582157  /lib/ld-uClibc-0.9.28.so
	c3180000-c31dede4 r-xs 00000000 00:0b 14582179  /lib/libuClibc-0.9.28.so
	c3520000-c352278c rw-p 00000000 00:0b 13763417  /doshm
	c3584000-c35865e8 r-xs 00000000 00:0b 13763417  /doshm
	c3588000-c358aa00 rw-p 00008000 00:0b 14582157  /lib/ld-uClibc-0.9.28.so
	c3590000-c359b6c0 rw-p 00000000 00:00 0
	c3620000-c3640000 rwxp 00000000 00:00 0
	c3700000-c37fa000 rw-S 00000000 00:06 1411      /SYSV00000000 (deleted)
	c3700000-c37fa000 rw-S 00000000 00:06 1411      /SYSV00000000 (deleted)
	nattch 1

To two after the patch:

	# /doshm sysv
	Command: sysv
	shmid: 0
	memory: 0xc3700000
	c0bb0000-c0bba788 r-xs 00000000 00:0b 14582157  /lib/ld-uClibc-0.9.28.so
	c3180000-c31dede4 r-xs 00000000 00:0b 14582179  /lib/libuClibc-0.9.28.so
	c3320000-c3340000 rwxp 00000000 00:00 0
	c3530000-c35325e8 r-xs 00000000 00:0b 13763417  /doshm
	c3534000-c353678c rw-p 00000000 00:0b 13763417  /doshm
	c3538000-c353aa00 rw-p 00008000 00:0b 14582157  /lib/ld-uClibc-0.9.28.so
	c3590000-c359b6c0 rw-p 00000000 00:00 0
	c35a4000-c35a8000 rw-p 00000000 00:00 0
	c3700000-c37fa000 rw-S 00000000 00:06 1369      /SYSV00000000 (deleted)
	c3700000-c37fa000 rw-S 00000000 00:06 1369      /SYSV00000000 (deleted)
	nattch 2

That's +1 to nattch for each shmat() made.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-22 19:39:06 -07:00
David Howells d56e03cd27 [PATCH] NOMMU: supply get_unmapped_area() to fix NOMMU SYSV SHM
Supply a get_unmapped_area() to fix NOMMU SYSV SHM support.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Adam Litke <agl@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-22 19:39:05 -07:00
Josef Sipek e9536ae720 [PATCH] struct path: convert mm
Signed-off-by: Josef Sipek <jsipek@fsl.cs.sunysb.edu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 08:28:47 -08:00
Burman Yan 4668edc334 [PATCH] kernel core: replace kmalloc+memset with kzalloc
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:41 -08:00
Mike Frysinger f81cff0d40 [PATCH] uclinux: fix mmap() of directory for nommu case
I was playing with blackfin when i hit a neat bug ... doing an open() on a
directory and then passing that fd to mmap() would cause the kernel to hang

after poking into the code a bit more, i found that
mm/nommu.c:validate_mmap_request() checks the length and if it is 0, just
returns the address ... this is in stark contrast to mmu's
mm/mmap.c:do_mmap_pgoff() where it returns -EINVAL for 0 length requests ...
i then noticed that some other parts of the logic is out of date between the
two funcs, so perhaps that's the easy fix ?

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 07:41:26 -08:00
Michael Opdenacker c1c8897f83 Spelling fix: "control" instead of "cotrol"
This patch against fixes a spelling mistake ("control" instead of "cotrol").

Signed-off-by: Michael Opdenacker <michael@free-electrons.com>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-10-03 23:21:02 +02:00
Gavin Lambert 3fcd03e070 [PATCH] NOMMU: don't try and give NULL to fput()
Don't try and give NULL to fput() in the error handling in do_mmap_pgoff()
as it'll cause an oops.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:17 -07:00
David Howells 930e652a21 [PATCH] NOMMU: Make futexes work under NOMMU conditions
Make futexes work under NOMMU conditions.

This can be tested by running this in one shell:

	#define SYSERROR(X, Y) \
		do { if ((long)(X) == -1L) { perror(Y); exit(1); }} while(0)

	int main()
	{
		int shmid, tmp, *f, n;

		shmid = shmget(23, 4, IPC_CREAT|0666);
		SYSERROR(shmid, "shmget");

		f = shmat(shmid, NULL, 0);
		SYSERROR(f, "shmat");

		n = *f;
		printf("WAIT: %p{%x}\n", f, n);
		tmp = futex(f, FUTEX_WAIT, n, NULL, NULL, 0);
		SYSERROR(tmp, "futex");
		printf("WAITED: %d\n", tmp);

		tmp = shmdt(f);
		SYSERROR(tmp, "shmdt");

		exit(0);
	}

And then this in the other shell:

	#define SYSERROR(X, Y) \
		do { if ((long)(X) == -1L) { perror(Y); exit(1); }} while(0)

	int main()
	{
		int shmid, tmp, *f;

		shmid = shmget(23, 4, IPC_CREAT|0666);
		SYSERROR(shmid, "shmget");

		f = shmat(shmid, NULL, 0);
		SYSERROR(f, "shmat");

		(*f)++;
		printf("WAKE: %p{%x}\n", f, *f);
		tmp = futex(f, FUTEX_WAKE, 1, NULL, NULL, 0);
		SYSERROR(tmp, "futex");
		printf("WOKE: %d\n", tmp);

		tmp = shmdt(f);
		SYSERROR(tmp, "shmdt");

		exit(0);
	}

The first program will set up a SYSV IPC SHM segment and wait on a futex in it
for the number at the start to change.  The program will increment that number
and wake the first program up.  This leads to output of the form:

	SHELL 1			SHELL 2
	=======================	=======================
	# /dowait
	WAIT: 0xc32ac000{0}
				# /dowake
				WAKE: 0xc32ac000{1}
	WAITED: 0		WOKE: 1

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-27 08:26:15 -07:00
David Howells 6fa5f80bc3 [PATCH] NOMMU: Make mremap() partially work for NOMMU kernels
Make mremap() partially work for NOMMU kernels.  It may resize a VMA provided
that it doesn't exceed the size of the slab object in which the storage is
allocated that the VMA refers to.  Shareable VMAs may not be resized.

Moving VMAs (as permitted by MREMAP_MAYMOVE) is not currently supported.

This patch also makes use of the fact that the VMA list is now ordered to cut
it short when possible.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-27 08:26:14 -07:00
David Howells 3034097a50 [PATCH] NOMMU: Order the per-mm_struct VMA list
Order the per-mm_struct VMA list by address so that searching it can be cut
short when the appropriate address has been exceeded.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-27 08:26:14 -07:00
David Howells d00c7b9937 [PATCH] NOMMU: Permit ptrace to ignore non-PROT_WRITE VMAs in NOMMU mode
Permit ptrace to modify a section that's non-shared but is marked
unwritable, such as is obtained by mapping the text segment of an ELF-FDPIC
executable binary with into a binary that's being ptraced[*].

[*] Under NOMMU conditions ptrace causes read-only MAP_PRIVATE mmaps to become
    totally private copies because if a private mapping was actually shared
    then the debugging setting breakpoints in it would potentially crash
    other processes.

This is done by using the VM_MAYWRITE flag rather than the VM_WRITE flag
when deciding whether to permit a write.

Without this patch a debugger can't set breakpoints in the mapped text
sections of executables that are mapped read-only private, even if the
mmap() syscall has taken a private copy because PT_PTRACED is set.

In addition, VM_MAYREAD is used instead of VM_READ for similar reasons.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-27 08:26:14 -07:00
David Howells 7b4d5b8b39 [PATCH] NOMMU: Check VMA protections
Check the VMA protections in get_user_pages() against what's being asked.

This checks to see that we don't accidentally write on a non-writable VMA or
permit an I/O mapping VMA to be accessed (which may lack page structs).

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-27 08:26:14 -07:00
Sonic Zhang 910e46da4b [PATCH] Check if start address is in vma region in NOMMU function get_user_pages()
In NOMMU arch, if run "cat /proc/self/mem", data from physical address 0
are read.  This behavior is different from MMU arch.  In IA32, message
"cat: /proc/self/mem: Input/output error" is reported.

This issue is rootcaused by not validate the start address in NOMMU
function get_user_pages().  Following patch solves this issue.

Signed-off-by: Sonic Zhang <sonic.adi@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-27 08:26:14 -07:00
David Howells 0159b141d8 [PATCH] NOMMU: Use find_vma() rather than reimplementing a VMA search
Use find_vma() in the NOMMU version of access_process_vm() rather than
reimplementing it.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-27 08:26:14 -07:00
David Howells 0ec76a110f [PATCH] NOMMU: Check that access_process_vm() has a valid target
Check that access_process_vm() is accessing a valid mapping in the target
process.

This limits ptrace() accesses and accesses through /proc/<pid>/maps to only
those regions actually mapped by a program.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-27 08:26:14 -07:00
Christoph Lameter 972d1a7b14 [PATCH] ZVC: Support NR_SLAB_RECLAIMABLE / NR_SLAB_UNRECLAIMABLE
Remove the atomic counter for slab_reclaim_pages and replace the counter
and NR_SLAB with two ZVC counter that account for unreclaimable and
reclaimable slab pages: NR_SLAB_RECLAIMABLE and NR_SLAB_UNRECLAIMABLE.

Change the check in vmscan.c to refer to to NR_SLAB_RECLAIMABLE.  The
intend seems to be to check for slab pages that could be freed.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:51 -07:00
Luke Yang 22c4af4092 [PATCH] nommu: export two symbols for drivers to use
nommu.c needs to export two more symbols for drivers to use:
remap_pfn_range and unmap_mapping_range.

Signed-off-by: Luke Yang <luke.adi@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-14 21:53:53 -07:00
Christoph Lameter 347ce434d5 [PATCH] zoned vm counters: conversion of nr_pagecache to per zone counter
Currently a single atomic variable is used to establish the size of the page
cache in the whole machine.  The zoned VM counters have the same method of
implementation as the nr_pagecache code but also allow the determination of
the pagecache size per zone.

Remove the special implementation for nr_pagecache and make it a zoned counter
named NR_FILE_PAGES.

Updates of the page cache counters are always performed with interrupts off.
We can therefore use the __ variant here.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-30 11:25:34 -07:00
Hideo AOKI d5ddc79bca [PATCH] overcommit: use totalreserve_pages for nommu
This patch is an enhancement of OVERCOMMIT_GUESS algorithm in
__vm_enough_memory() in mm/nommu.c.

When the OVERCOMMIT_GUESS algorithm calculates the number of free pages,
the algorithm subtracts the number of reserved pages from the result
nr_free_pages().

Signed-off-by: Hideo Aoki <haoki@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-11 06:18:32 -07:00
Nick Piggin 84097518d1 [PATCH] mm: nommu use compound pages
Now that compound page handling is properly fixed in the VM, move nommu
over to using compound pages rather than rolling their own refcounting.

nommu vm page refcounting is broken anyway, but there is no need to have
divergent code in the core VM now, nor when it gets fixed.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: David Howells <dhowells@redhat.com>

(Needs testing, please).
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-22 07:54:01 -08:00
Andrew Morton f61388822a [PATCH] nommu: implement vmalloc_node()
Fix oprofile linkage.   Pointed out by "Luke Yang" <luke.adi@gmail.com>.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-28 20:53:44 -08:00
Luke Yang 7a9166e3b0 [PATCH] Fix undefined symbols for nommu architecture
Signed-off-by: Luke Yang <luke.adi@gmail.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-20 20:00:11 -08:00