linux.git/arch/sh/mm, branch v3.14.41

vm: add VM_FAULT_SIGSEGV handling support

2015-04-29T08:31:55+00:00

commit 33692f27597fcab536d7cbbcc8f52905133e4aa7 upstream.

The core VM already knows about VM_FAULT_SIGBUS, but cannot return a
"you should SIGSEGV" error, because the SIGSEGV case was generally
handled by the caller - usually the architecture fault handler.

That results in lots of duplication - all the architecture fault
handlers end up doing very similar "look up vma, check permissions, do
retries etc" - but it generally works.  However, there are cases where
the VM actually wants to SIGSEGV, and applications _expect_ SIGSEGV.

In particular, when accessing the stack guard page, libsigsegv expects a
SIGSEGV.  And it usually got one, because the stack growth is handled by
that duplicated architecture fault handler.

However, when the generic VM layer started propagating the error return
from the stack expansion in commit fee7e49d4514 ("mm: propagate error
from stack expansion even for guard page"), that now exposed the
existing VM_FAULT_SIGBUS result to user space.  And user space really
expected SIGSEGV, not SIGBUS.

To fix that case, we need to add a VM_FAULT_SIGSEGV, and teach all those
duplicate architecture fault handlers about it.  They all already have
the code to handle SIGSEGV, so it's about just tying that new return
value to the existing code, but it's all a bit annoying.

This is the mindless minimal patch to do this.  A more extensive patch
would be to try to gather up the mostly shared fault handling logic into
one generic helper routine, and long-term we really should do that
cleanup.

Just from this patch, you can generally see that most architectures just
copied (directly or indirectly) the old x86 way of doing things, but in
the meantime that original x86 model has been improved to hold the VM
semaphore for shorter times etc and to handle VM_FAULT_RETRY and other
"newer" things, so it would be a good idea to bring all those
improvements to the generic case and teach other architectures about
them too.

Reported-and-tested-by: Takashi Iwai 
Tested-by: Jan Engelhardt 
Acked-by: Heiko Carstens  # "s390 still compiles and boots"
Cc: linux-arch@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds 
[shengyong: Backport to 3.14
 - adjust context
 - ignore modification for arch nios2, because 3.14 does not support it
 - add SIGSEGV handling to powerpc/cell spu_fault.c, because 3.14 does not
   separate it to copro_fault.c
 - add SIGSEGV handling to mm/memory.c, because 3.14 does not separate it
   to gup.c
]
Signed-off-by: Sheng Yong 
Signed-off-by: Greg Kroah-Hartman

hugetlb: restrict hugepage_migration_support() to x86_64

2014-07-01T03:11:53+00:00

commit c177c81e09e517bbf75b67762cdab1b83aba6976 upstream.

Currently hugepage migration is available for all archs which support
pmd-level hugepage, but testing is done only for x86_64 and there're
bugs for other archs.  So to avoid breaking such archs, this patch
limits the availability strictly to x86_64 until developers of other
archs get interested in enabling this feature.

Simply disabling hugepage migration on non-x86_64 archs is not enough to
fix the reported problem where sys_move_pages() hits the BUG_ON() in
follow_page(FOLL_GET), so let's fix this by checking if hugepage
migration is supported in vma_migratable().

Signed-off-by: Naoya Horiguchi 
Reported-by: Michael Ellerman 
Tested-by: Michael Ellerman 
Acked-by: Hugh Dickins 
Cc: Benjamin Herrenschmidt 
Cc: Tony Luck 
Cc: Russell King 
Cc: Martin Schwidefsky 
Cc: James Hogan 
Cc: Ralf Baechle 
Cc: David Miller 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

sh: prefix sh-specific "CCR" and "CCR2" by "SH_"

2014-03-04T15:55:49+00:00

Commit bcf24e1daa94 ("mmc: omap_hsmmc: use the generic config for
omap2plus devices"), enabled the build for other platforms for compile
testing.

sh-allmodconfig now fails with:

    include/linux/omap-dma.h:171:8: error: expected identifier before numeric constant
    make[4]: *** [drivers/mmc/host/omap_hsmmc.o] Error 1

This happens because SuperH #defines "CCR", which is one of the enum
values in include/linux/omap-dma.h.  There's a similar issue with "CCR2"
on sh2a.

As "CCR" and "CCR2" are too generic names for global #defines, prefix
them with "SH_" to fix this.

Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: use pgdat_end_pfn() to simplify the code in arch

2013-11-13T03:09:03+00:00

Use "pgdat_end_pfn()" instead of "pgdat->node_start_pfn +
pgdat->node_spanned_pages".  Simplify the code, no functional change.

Signed-off-by: Xishi Qiu 
Cc: James Hogan 
Cc: "Luck, Tony" 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: Paul Mundt 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

arch: mm: pass userspace fault flag to generic fault handler

2013-09-12T22:38:01+00:00

Unlike global OOM handling, memory cgroup code will invoke the OOM killer
in any OOM situation because it has no way of telling faults occuring in
kernel context - which could be handled more gracefully - from
user-triggered faults.

Pass a flag that identifies faults originating in user space from the
architecture-specific fault handlers to generic code so that memcg OOM
handling can be improved.

Signed-off-by: Johannes Weiner 
Reviewed-by: Michal Hocko 
Cc: David Rientjes 
Cc: KAMEZAWA Hiroyuki 
Cc: azurIt 
Cc: KOSAKI Motohiro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: migrate: check movability of hugepage in unmap_and_move_huge_page()

2013-09-11T22:57:49+00:00

Currently hugepage migration works well only for pmd-based hugepages
(mainly due to lack of testing,) so we had better not enable migration of
other levels of hugepages until we are ready for it.

Some users of hugepage migration (mbind, move_pages, and migrate_pages) do
page table walk and check pud/pmd_huge() there, so they are safe.  But the
other users (softoffline and memory hotremove) don't do this, so without
this patch they can try to migrate unexpected types of hugepages.

To prevent this, we introduce hugepage_migration_support() as an
architecture dependent check of whether hugepage are implemented on a pmd
basis or not.  And on some architecture multiple sizes of hugepages are
available, so hugepage_migration_support() also checks hugepage size.

Signed-off-by: Naoya Horiguchi 
Cc: Andi Kleen 
Cc: Hillf Danton 
Cc: Wanpeng Li 
Cc: Mel Gorman 
Cc: Hugh Dickins 
Cc: KOSAKI Motohiro 
Cc: Michal Hocko 
Cc: Rik van Riel 
Cc: "Aneesh Kumar K.V" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

sh: delete __cpuinit usage from all sh files

2013-07-14T23:36:53+00:00

The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications.  For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.

After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out.  Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.

Note that some harmless section mismatch warnings may result, since
notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
are flagged as __cpuinit  -- so if we remove the __cpuinit from
arch specific callers, we will also get section mismatch warnings.
As an intermediate step, we intend to turn the linux/init.h cpuinit
content into no-ops as early as possible, since that will get rid
of these warnings.  In any case, they are temporary and harmless.

This removes all the arch/sh uses of the __cpuinit macros from
all C files.  Currently sh does not have any __CPUINIT used in
assembly files.

[1] https://lkml.org/lkml/2013/5/20/589

Cc: Paul Mundt 
Cc: linux-sh@vger.kernel.org
Signed-off-by: Paul Gortmaker

mm/SH: prepare for killing free_all_bootmem_node()

2013-07-03T23:07:39+00:00

Prepare for killing free_all_bootmem_node() by using free_all_bootmem().

Signed-off-by: Jiang Liu 
Cc: Paul Mundt 
Cc: Wen Congyang 
Cc: Tang Chen 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/SH: prepare for removing num_physpages and simplify mem_init()

2013-07-03T23:07:37+00:00

Prepare for removing num_physpages and simplify mem_init().

Signed-off-by: Jiang Liu 
Cc: Paul Mundt 
Cc: Wen Congyang 
Cc: Tang Chen 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: concentrate modification of totalram_pages into the mm core

2013-07-03T23:07:33+00:00

Concentrate code to modify totalram_pages into the mm core, so the arch
memory initialized code doesn't need to take care of it.  With these
changes applied, only following functions from mm core modify global
variable totalram_pages: free_bootmem_late(), free_all_bootmem(),
free_all_bootmem_node(), adjust_managed_page_count().

With this patch applied, it will be much more easier for us to keep
totalram_pages and zone->managed_pages in consistence.

Signed-off-by: Jiang Liu 
Acked-by: David Howells 
Cc: "H. Peter Anvin" 
Cc: "Michael S. Tsirkin" 
Cc: 
Cc: Arnd Bergmann 
Cc: Catalin Marinas 
Cc: Chris Metcalf 
Cc: Geert Uytterhoeven 
Cc: Ingo Molnar 
Cc: Jeremy Fitzhardinge 
Cc: Jianguo Wu 
Cc: Joonsoo Kim 
Cc: Kamezawa Hiroyuki 
Cc: Konrad Rzeszutek Wilk 
Cc: Marek Szyprowski 
Cc: Mel Gorman 
Cc: Michel Lespinasse 
Cc: Minchan Kim 
Cc: Rik van Riel 
Cc: Rusty Russell 
Cc: Tang Chen 
Cc: Tejun Heo 
Cc: Thomas Gleixner 
Cc: Wen Congyang 
Cc: Will Deacon 
Cc: Yasuaki Ishimatsu 
Cc: Yinghai Lu 
Cc: Russell King 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds