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commit 23493c121912a39f0262e0dbeb236e1d39efa4d5 upstream.
The offset of hugepage block will not be 16G, if the expected
page is more than one. Calculate the totol size instead of the
hardcode value.
Fixes: 4792adbac9eb ("powerpc: Don't use a 16G page if beyond mem= limits")
Signed-off-by: Rui Teng <rui.teng@linux.vnet.ibm.com>
Tested-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 1be7107fbe18eed3e319a6c3e83c78254b693acb upstream.
Stack guard page is a useful feature to reduce a risk of stack smashing
into a different mapping. We have been using a single page gap which
is sufficient to prevent having stack adjacent to a different mapping.
But this seems to be insufficient in the light of the stack usage in
userspace. E.g. glibc uses as large as 64kB alloca() in many commonly
used functions. Others use constructs liks gid_t buffer[NGROUPS_MAX]
which is 256kB or stack strings with MAX_ARG_STRLEN.
This will become especially dangerous for suid binaries and the default
no limit for the stack size limit because those applications can be
tricked to consume a large portion of the stack and a single glibc call
could jump over the guard page. These attacks are not theoretical,
unfortunatelly.
Make those attacks less probable by increasing the stack guard gap
to 1MB (on systems with 4k pages; but make it depend on the page size
because systems with larger base pages might cap stack allocations in
the PAGE_SIZE units) which should cover larger alloca() and VLA stack
allocations. It is obviously not a full fix because the problem is
somehow inherent, but it should reduce attack space a lot.
One could argue that the gap size should be configurable from userspace,
but that can be done later when somebody finds that the new 1MB is wrong
for some special case applications. For now, add a kernel command line
option (stack_guard_gap) to specify the stack gap size (in page units).
Implementation wise, first delete all the old code for stack guard page:
because although we could get away with accounting one extra page in a
stack vma, accounting a larger gap can break userspace - case in point,
a program run with "ulimit -S -v 20000" failed when the 1MB gap was
counted for RLIMIT_AS; similar problems could come with RLIMIT_MLOCK
and strict non-overcommit mode.
Instead of keeping gap inside the stack vma, maintain the stack guard
gap as a gap between vmas: using vm_start_gap() in place of vm_start
(or vm_end_gap() in place of vm_end if VM_GROWSUP) in just those few
places which need to respect the gap - mainly arch_get_unmapped_area(),
and and the vma tree's subtree_gap support for that.
Original-patch-by: Oleg Nesterov <oleg@redhat.com>
Original-patch-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Tested-by: Helge Deller <deller@gmx.de> # parisc
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[Hugh Dickins: Backported to 3.2]
[bwh: Fix more instances of vma->vm_start in sparc64 impl. of
arch_get_unmapped_area_topdown() and generic impl. of
hugetlb_get_unmapped_area()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 45b64ee64970dee9392229302efe1d1567e8d304 upstream.
memory_hotplug_max() uses hot_add_drconf_memory_max() to get maxmimum
addressable memory by referring to ibm,dyanamic-memory property. There
are three problems with the current approach:
1 hot_add_drconf_memory_max() assumes that ibm,dynamic-memory includes
all the LMBs of the guest, but that is not true for PowerKVM which
populates only DR LMBs (LMBs that can be hotplugged/removed) in that
property.
2 hot_add_drconf_memory_max() multiplies lmb-size with lmb-count to arrive
at the max possible address. Since ibm,dynamic-memory doesn't include
RMA LMBs, the address thus obtained will be less than the actual max
address. For example, if max possible memory size is 32G, with lmb-size
of 256MB there can be 127 LMBs in ibm,dynamic-memory (1 LMB for RMA
which won't be present here). hot_add_drconf_memory_max() would then
return the max addressable memory as 127 * 256MB = 31.75GB, the max
address should have been 32G which is what ibm,lrdr-capacity shows.
3 In PowerKVM, there can be a gap between the end of boot time RAM and
beginning of hotplug RAM area. So just multiplying lmb-count with
lmb-size will not provide the correct max possible address for PowerKVM.
This patch fixes 1 by using ibm,lrdr-capacity property to return the max
addressable memory whenever the property is present. Then it fixes 2 & 3
by fetching the address of the last LMB in ibm,dynamic-memory property.
Fixes: cd34206e949b ("powerpc: Add memory_hotplug_max()")
Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit aac55d7573c5d46ed9a62818d5d3e69dd2060105 upstream.
With Linux page size of 64K and hardware only supporting 4K HPTE, if we
use subpage protection, we always fail for the subpage 0 as shown
below (using the selftest subpage_prot test):
520175565: (4520111850): Failed at 0x3fffad4b0000 (p=13,sp=0,w=0), want=fault, got=pass !
4520890210: (4520826495): Failed at 0x3fffad5b0000 (p=29,sp=0,w=0), want=fault, got=pass !
4521574251: (4521510536): Failed at 0x3fffad6b0000 (p=45,sp=0,w=0), want=fault, got=pass !
4522258324: (4522194609): Failed at 0x3fffad7b0000 (p=61,sp=0,w=0), want=fault, got=pass !
This is because hash preload wrongly inserts the HPTE entry for subpage
0 without looking at the subpage protection information.
Fix it by teaching should_hash_preload() not to preload if we have
subpage protection configured for that range.
It appears this has been broken since it was introduced in 2008.
Fixes: fa28237cfcc5 ("[POWERPC] Provide a way to protect 4k subpages when using 64k pages")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
[mpe: Rework into should_hash_preload() to avoid build fails w/SLICES=n]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 8bbc9b7b001eaab8abf7e9e24edf1bb285c8d825 upstream.
Currently we have a check in hash_preload() against the psize, which is
only included when CONFIG_PPC_MM_SLICES is enabled. We want to expand
this check in a subsequent patch, so factor it out to allow that. As a
bonus it removes the #ifdef in the C code.
Unfortunately we can't put this in the existing CONFIG_PPC_MM_SLICES
block because it would require a forward declaration.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit fa8cbaaf5a68f62db3f9a8444ecbb940b47984cb upstream.
Since commit 8a0a9bd4db63bc45e301, this comment in mmap_rnd() does not
hold true as the value returned by get_random_int() will in fact be
different every single call. Remove the comment and simplify the code
back to its original desired form.
This reverts commit a5adc91a4b44b5d1 which is no longer necessary and
also fixes the sparc code that copied this same adjustment.
Signed-off-by: Dan McGee <dpmcgee@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Moritz Mühlenhoff <jmm@inutil.org>
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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 <tiwai@suse.de>
Tested-by: Jan Engelhardt <jengelh@inai.de>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # "s390 still compiles and boots"
Cc: linux-arch@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.2:
- Adjust filenames, context
- Drop arc, metag, nios2 and lustre changes
- For sh, patch both 32-bit and 64-bit implementations to use goto bad_area
- For s390, pass int_code and trans_exc_code as arguments to do_no_context()
and do_sigsegv()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 83d5e64b7efa7f39b10ff5e92792e807a720289c upstream.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit b00fc6ec1f24f9d7af9b8988b6a198186eb3408c upstream.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=81631
Reported-by: David Binderman <dcb314@hotmail.com>
Signed-off-by: Andrey Utkin <andrey.krieger.utkin@gmail.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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commit 7122beeee7bc1757682049780179d7c216dd1c83 upstream.
The following commit breaks numa distance setup for old powerpc
systems that use form0 encoding in device tree.
commit 41eab6f88f24124df89e38067b3766b7bef06ddb
powerpc/numa: Use form 1 affinity to setup node distance
Device tree node /rtas/ibm,associativity-reference-points would
index into /cpus/PowerPCxxxx/ibm,associativity based on form0 or
form1 encoding detected by ibm,architecture-vec-5 property.
All modern systems use form1 and current kernel code is correct.
However, on older systems with form0 encoding, the numa distance
will get hard coded as LOCAL_DISTANCE for all nodes. This causes
task scheduling anomaly since scheduler will skip building numa
level domain (topmost domain with all cpus) if all numa distances
are same. (value of 'level' in sched_init_numa() will remain 0)
Prior to the above commit:
((from) == (to) ? LOCAL_DISTANCE : REMOTE_DISTANCE)
Restoring compatible behavior with this patch for old powerpc systems
with device tree where numa distance are encoded as form0.
Signed-off-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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arch/powerpc/mm/hugetlbpage.c: In function 'reserve_hugetlb_gpages':
arch/powerpc/mm/hugetlbpage.c:312:2: error: implicit declaration of function 'parse_args'
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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This patch adds support for numa topology on powernv platforms running
OPAL formware. It checks for the type of platform at run time and
sets the affinity form correctly so that NUMA topology can be discovered
correctly.
Signed-off-by: Dipankar Sarma <dipankar@in.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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We've resisted adding System RAM to /proc/iomem because it is
the wrong place for it. Unfortunately we continue to find tools
that rely on this behaviour so give up and add it in.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux
* 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits)
Revert "tracing: Include module.h in define_trace.h"
irq: don't put module.h into irq.h for tracking irqgen modules.
bluetooth: macroize two small inlines to avoid module.h
ip_vs.h: fix implicit use of module_get/module_put from module.h
nf_conntrack.h: fix up fallout from implicit moduleparam.h presence
include: replace linux/module.h with "struct module" wherever possible
include: convert various register fcns to macros to avoid include chaining
crypto.h: remove unused crypto_tfm_alg_modname() inline
uwb.h: fix implicit use of asm/page.h for PAGE_SIZE
pm_runtime.h: explicitly requires notifier.h
linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h
miscdevice.h: fix up implicit use of lists and types
stop_machine.h: fix implicit use of smp.h for smp_processor_id
of: fix implicit use of errno.h in include/linux/of.h
of_platform.h: delete needless include <linux/module.h>
acpi: remove module.h include from platform/aclinux.h
miscdevice.h: delete unnecessary inclusion of module.h
device_cgroup.h: delete needless include <linux/module.h>
net: sch_generic remove redundant use of <linux/module.h>
net: inet_timewait_sock doesnt need <linux/module.h>
...
Fix up trivial conflicts (other header files, and removal of the ab3550 mfd driver) in
- drivers/media/dvb/frontends/dibx000_common.c
- drivers/media/video/{mt9m111.c,ov6650.c}
- drivers/mfd/ab3550-core.c
- include/linux/dmaengine.h
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git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (106 commits)
powerpc/p3060qds: Add support for P3060QDS board
powerpc/83xx: Add shutdown request support to MCU handling on MPC8349 MITX
powerpc/85xx: Make kexec to interate over online cpus
powerpc/fsl_booke: Fix comment in head_fsl_booke.S
powerpc/85xx: issue 15 EOI after core reset for FSL CoreNet devices
powerpc/8xxx: Fix interrupt handling in MPC8xxx GPIO driver
powerpc/85xx: Add 'fsl,pq3-gpio' compatiable for GPIO driver
powerpc/86xx: Correct Gianfar support for GE boards
powerpc/cpm: Clear muram before it is in use.
drivers/virt: add ioctl for 32-bit compat on 64-bit to fsl-hv-manager
powerpc/fsl_msi: add support for "msi-address-64" property
powerpc/85xx: Setup secondary cores PIR with hard SMP id
powerpc/fsl-booke: Fix settlbcam for 64-bit
powerpc/85xx: Adding DCSR node to dtsi device trees
powerpc/85xx: clean up FPGA device tree nodes for Freecsale QorIQ boards
powerpc/85xx: fix PHYS_64BIT selection for P1022DS
powerpc/fsl-booke: Fix setup_initial_memory_limit to not blindly map
powerpc: respect mem= setting for early memory limit setup
powerpc: Update corenet64_smp_defconfig
powerpc: Update mpc85xx/corenet 32-bit defconfigs
...
Fix up trivial conflicts in:
- arch/powerpc/configs/40x/hcu4_defconfig
removed stale file, edited elsewhere
- arch/powerpc/include/asm/udbg.h, arch/powerpc/kernel/udbg.c:
added opal and gelic drivers vs added ePAPR driver
- drivers/tty/serial/8250.c
moved UPIO_TSI to powerpc vs removed UPIO_DWAPB support
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This avoids duplicating the function in every arch gup_fast.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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powerpc didn't return 0 in that case, if it's rolling back the *nr pointer
it should also return zero to avoid adding pages to the array at the wrong
offset.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Up to this point the code assumed old refcounting for hugepages (pre-thp).
This updates the code directly to the thp mapcount tail page refcounting.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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We only taken "refs" pins on the head page not "*nr" pins.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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"page" may have changed to point to the next hugepage after the loop
completed, The references have been taken on the head page, so the
put_page must happen there too.
This is a longstanding issue pre-thp inclusion.
It's totally unclear how these page_cache_add_speculative and
pte_val(pte) != pte_val(*ptep) checks are necessary across all the
powerpc gup_fast code, when x86 doesn't need any of that: there's no way
the page can be freed with irq disabled so we're guaranteed the
atomic_inc will happen on a page with page_count > 0 (so not needing the
speculative check).
The pte check is also meaningless on x86: no need to rollback on x86 if
the pte changed, because the pte can still change a CPU tick after the
check succeeded and it won't be rolled back in that case. The important
thing is we got a reference on a valid page that was mapped there a CPU
tick ago. So not knowing the soft tlb refill code of ppc64 in great
detail I'm not removing the "speculative" page_count increase and the
pte checks across all the code, but unless there's a strong reason for
it they should be later cleaned up too.
If a pte can change from huge to non-huge (like it could happen with
THP) passing a pte_t *ptep to gup_hugepte() would also require to repeat
the is_hugepd in gup_hugepte(), but that shouldn't happen with hugetlbfs
only so I'm not altering that.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This part of gup_fast doesn't seem capable of handling hugetlbfs ptes,
those should be handled by gup_hugepd only, so these checks are
superfluous.
Plus if this wasn't a noop, it would have oopsed because, the insistence
of using the speculative refcounting would trigger a VM_BUG_ON if a tail
page was encountered in the page_cache_get_speculative().
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Michel while working on the working set estimation code, noticed that
calling get_page_unless_zero() on a random pfn_to_page(random_pfn)
wasn't safe, if the pfn ended up being a tail page of a transparent
hugepage under splitting by __split_huge_page_refcount().
He then found the problem could also theoretically materialize with
page_cache_get_speculative() during the speculative radix tree lookups
that uses get_page_unless_zero() in SMP if the radix tree page is freed
and reallocated and get_user_pages is called on it before
page_cache_get_speculative has a chance to call get_page_unless_zero().
So the best way to fix the problem is to keep page_tail->_count zero at
all times. This will guarantee that get_page_unless_zero() can never
succeed on any tail page. page_tail->_mapcount is guaranteed zero and
is unused for all tail pages of a compound page, so we can simply
account the tail page references there and transfer them to
tail_page->_count in __split_huge_page_refcount() (in addition to the
head_page->_mapcount).
While debugging this s/_count/_mapcount/ change I also noticed get_page is
called by direct-io.c on pages returned by get_user_pages. That wasn't
entirely safe because the two atomic_inc in get_page weren't atomic. As
opposed to other get_user_page users like secondary-MMU page fault to
establish the shadow pagetables would never call any superflous get_page
after get_user_page returns. It's safer to make get_page universally safe
for tail pages and to use get_page_foll() within follow_page (inside
get_user_pages()). get_page_foll() is safe to do the refcounting for tail
pages without taking any locks because it is run within PT lock protected
critical sections (PT lock for pte and page_table_lock for
pmd_trans_huge).
The standard get_page() as invoked by direct-io instead will now take
the compound_lock but still only for tail pages. The direct-io paths
are usually I/O bound and the compound_lock is per THP so very
finegrined, so there's no risk of scalability issues with it. A simple
direct-io benchmarks with all lockdep prove locking and spinlock
debugging infrastructure enabled shows identical performance and no
overhead. So it's worth it. Ideally direct-io should stop calling
get_page() on pages returned by get_user_pages(). The spinlock in
get_page() is already optimized away for no-THP builds but doing
get_page() on tail pages returned by GUP is generally a rare operation
and usually only run in I/O paths.
This new refcounting on page_tail->_mapcount in addition to avoiding new
RCU critical sections will also allow the working set estimation code to
work without any further complexity associated to the tail page
refcounting with THP.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reported-by: Michel Lespinasse <walken@google.com>
Reviewed-by: Michel Lespinasse <walken@google.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: <stable@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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All these files were including module.h just for the basic
EXPORT_SYMBOL infrastructure. We can shift them off to the
export.h header which is a way smaller footprint and thus
realize some compile time gains.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
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Fix failures in powerpc associated with the previously allowed
implicit module.h presence that now lead to things like this:
arch/powerpc/mm/mmu_context_hash32.c:76:1: error: type defaults to 'int' in declaration of 'EXPORT_SYMBOL_GPL'
arch/powerpc/mm/tlb_hash32.c:48:1: error: type defaults to 'int' in declaration of 'EXPORT_SYMBOL'
arch/powerpc/kernel/pci_32.c:51:1: error: type defaults to 'int' in declaration of 'EXPORT_SYMBOL_GPL'
arch/powerpc/kernel/iomap.c:36:1: error: type defaults to 'int' in declaration of 'EXPORT_SYMBOL'
arch/powerpc/platforms/44x/canyonlands.c:126:1: error: type defaults to 'int' in declaration of 'EXPORT_SYMBOL'
arch/powerpc/kvm/44x.c:168:59: error: 'THIS_MODULE' undeclared (first use in this function)
[with several contibutions from Stephen Rothwell <sfr@canb.auug.org.au>]
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
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With module.h being implicitly everywhere via device.h, the absence
of explicitly including something for EXPORT_SYMBOL went unnoticed.
Since we are heading to fix things up and clean module.h from the
device.h file, we need to explicitly include these files now.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
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Currently, it does a cntlzd on the size and then subtracts it from
21.... this doesn't take into account the varying size of a "long".
Just use __ilog instead (and subtract the 10 we have to subtract
to get to the tsize encoding).
Also correct the comment about page sizes supported.
Signed-off-by: Becky Bruce <beckyb@kernel.crashing.org>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
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On FSL Book-E devices we support multiple large TLB sizes and so we can
get into situations in which the initial 1G TLB size is too big and
we're asked for a size that is not mappable by a single entry (like
512M). The single entry is important because when we bring up secondary
cores they need to ensure any data structure they need to access (eg
PACA or stack) is always mapped.
So we really need to determine what size will actually be mapped by the
first TLB entry to ensure we limit early memory references to that
region. We refactor the map_mem_in_cams() code to provider a helper
function that we can utilize to determine the size of the first TLB
entry while taking into account size and alignment constraints.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
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Commit 41151e77a4 ("powerpc: Hugetlb for BookE") added some
#ifdef CONFIG_MM_SLICES conditionals to hugetlb_get_unmapped_area()
and vma_mmu_pagesize(). Unfortunately this is not the correct config
symbol; it should be CONFIG_PPC_MM_SLICES. The result is that
attempting to use hugetlbfs on 64-bit Power server processors results
in an infinite stack recursion between get_unmapped_area() and
hugetlb_get_unmapped_area().
This fixes it by changing the #ifdef to use CONFIG_PPC_MM_SLICES
in those functions and also in book3e_hugetlb_preload().
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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The icswx code introduced an A-B B-A deadlock:
CPU0 CPU1
---- ----
lock(&anon_vma->mutex);
lock(&mm->mmap_sem);
lock(&anon_vma->mutex);
lock(&mm->mmap_sem);
Instead of using the mmap_sem to keep mm_users constant, take the
page table spinlock.
Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: <stable@kernel.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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If we echo an address the hypervisor doesn't like to
/sys/devices/system/memory/probe we oops the box:
# echo 0x10000000000 > /sys/devices/system/memory/probe
kernel BUG at arch/powerpc/mm/hash_utils_64.c:541!
The backtrace is:
create_section_mapping
arch_add_memory
add_memory
memory_probe_store
sysdev_class_store
sysfs_write_file
vfs_write
SyS_write
In create_section_mapping we BUG if htab_bolt_mapping returned
an error. A better approach is to return an error which will
propagate back to userspace.
Rerunning the test with this patch applied:
# echo 0x10000000000 > /sys/devices/system/memory/probe
-bash: echo: write error: Invalid argument
Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: stable@kernel.org
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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While converting code to use for_each_node_by_type I noticed a
number of coding style issues.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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Use for_each_node_by_type instead of open coding it.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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During memory hotplug testing, I got the following warning:
ERROR: Bad of_node_put() on /memory@0
of_node_release
kref_put
of_node_put
of_find_node_by_type
hot_add_node_scn_to_nid
hot_add_scn_to_nid
memory_add_physaddr_to_nid
...
of_find_node_by_type() loop does the of_node_put for us so we only
need the handle the case where we terminate the loop early.
As suggested by Stephen Rothwell we can do the of_node_put
unconditionally outside of the loop since of_node_put handles a
NULL argument fine.
Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: stable@kernel.org
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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Enable hugepages on Freescale BookE processors. This allows the kernel to
use huge TLB entries to map pages, which can greatly reduce the number of
TLB misses and the amount of TLB thrashing experienced by applications with
large memory footprints. Care should be taken when using this on FSL
processors, as the number of large TLB entries supported by the core is low
(16-64) on current processors.
The supported set of hugepage sizes include 4m, 16m, 64m, 256m, and 1g.
Page sizes larger than the max zone size are called "gigantic" pages and
must be allocated on the command line (and cannot be deallocated).
This is currently only fully implemented for Freescale 32-bit BookE
processors, but there is some infrastructure in the code for
64-bit BooKE.
Signed-off-by: Becky Bruce <beckyb@kernel.crashing.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (99 commits)
drivers/virt: add missing linux/interrupt.h to fsl_hypervisor.c
powerpc/85xx: fix mpic configuration in CAMP mode
powerpc: Copy back TIF flags on return from softirq stack
powerpc/64: Make server perfmon only built on ppc64 server devices
powerpc/pseries: Fix hvc_vio.c build due to recent changes
powerpc: Exporting boot_cpuid_phys
powerpc: Add CFAR to oops output
hvc_console: Add kdb support
powerpc/pseries: Fix hvterm_raw_get_chars to accept < 16 chars, fixing xmon
powerpc/irq: Quieten irq mapping printks
powerpc: Enable lockup and hung task detectors in pseries and ppc64 defeconfigs
powerpc: Add mpt2sas driver to pseries and ppc64 defconfig
powerpc: Disable IRQs off tracer in ppc64 defconfig
powerpc: Sync pseries and ppc64 defconfigs
powerpc/pseries/hvconsole: Fix dropped console output
hvc_console: Improve tty/console put_chars handling
powerpc/kdump: Fix timeout in crash_kexec_wait_realmode
powerpc/mm: Fix output of total_ram.
powerpc/cpufreq: Add cpufreq driver for Momentum Maple boards
powerpc: Correct annotations of pmu registration functions
...
Fix up trivial Kconfig/Makefile conflicts in arch/powerpc, drivers, and
drivers/cpufreq
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* 'kvm-updates/3.1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (143 commits)
KVM: IOMMU: Disable device assignment without interrupt remapping
KVM: MMU: trace mmio page fault
KVM: MMU: mmio page fault support
KVM: MMU: reorganize struct kvm_shadow_walk_iterator
KVM: MMU: lockless walking shadow page table
KVM: MMU: do not need atomicly to set/clear spte
KVM: MMU: introduce the rules to modify shadow page table
KVM: MMU: abstract some functions to handle fault pfn
KVM: MMU: filter out the mmio pfn from the fault pfn
KVM: MMU: remove bypass_guest_pf
KVM: MMU: split kvm_mmu_free_page
KVM: MMU: count used shadow pages on prepareing path
KVM: MMU: rename 'pt_write' to 'emulate'
KVM: MMU: cleanup for FNAME(fetch)
KVM: MMU: optimize to handle dirty bit
KVM: MMU: cache mmio info on page fault path
KVM: x86: introduce vcpu_mmio_gva_to_gpa to cleanup the code
KVM: MMU: do not update slot bitmap if spte is nonpresent
KVM: MMU: fix walking shadow page table
KVM guest: KVM Steal time registration
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (123 commits)
perf: Remove the nmi parameter from the oprofile_perf backend
x86, perf: Make copy_from_user_nmi() a library function
perf: Remove perf_event_attr::type check
x86, perf: P4 PMU - Fix typos in comments and style cleanup
perf tools: Make test use the preset debugfs path
perf tools: Add automated tests for events parsing
perf tools: De-opt the parse_events function
perf script: Fix display of IP address for non-callchain path
perf tools: Fix endian conversion reading event attr from file header
perf tools: Add missing 'node' alias to the hw_cache[] array
perf probe: Support adding probes on offline kernel modules
perf probe: Add probed module in front of function
perf probe: Introduce debuginfo to encapsulate dwarf information
perf-probe: Move dwarf library routines to dwarf-aux.{c, h}
perf probe: Remove redundant dwarf functions
perf probe: Move strtailcmp to string.c
perf probe: Rename DIE_FIND_CB_FOUND to DIE_FIND_CB_END
tracing/kprobe: Update symbol reference when loading module
tracing/kprobes: Support module init function probing
kprobes: Return -ENOENT if probe point doesn't exist
...
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On 32bit platforms that support >= 4GB memory total_ram was truncated.
This creates a confusing printk:
Top of RAM: 0x100000000, Total RAM: 0x0
Fix that:
Top of RAM: 0x100000000, Total RAM: 0x100000000
Signed-off-by: Tony Breeds <tony@bakeyournoodle.com>
Acked-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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The 44x code (which is shared by 47x) assumes the available physical memory
begins at 0x00000000. This is not necessarily the case in an AMP
environment.
Support CONFIG_RELOCATABLE for 476 in order to allow the kernel to be
loaded into a higher memory range.
Signed-off-by: Tony Breeds <tony@bakeyournoodle.com>
Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
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Since other OS's may be running on the other cores don't use tlbivax
Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Tony Breeds <tony@bakeyournoodle.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
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This adds support for running KVM guests in supervisor mode on those
PPC970 processors that have a usable hypervisor mode. Unfortunately,
Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to
1), but the YDL PowerStation does have a usable hypervisor mode.
There are several differences between the PPC970 and POWER7 in how
guests are managed. These differences are accommodated using the
CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature
bits. Notably, on PPC970:
* The LPCR, LPID or RMOR registers don't exist, and the functions of
those registers are provided by bits in HID4 and one bit in HID0.
* External interrupts can be directed to the hypervisor, but unlike
POWER7 they are masked by MSR[EE] in non-hypervisor modes and use
SRR0/1 not HSRR0/1.
* There is no virtual RMA (VRMA) mode; the guest must use an RMO
(real mode offset) area.
* The TLB entries are not tagged with the LPID, so it is necessary to
flush the whole TLB on partition switch. Furthermore, when switching
partitions we have to ensure that no other CPU is executing the tlbie
or tlbsync instructions in either the old or the new partition,
otherwise undefined behaviour can occur.
* The PMU has 8 counters (PMC registers) rather than 6.
* The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist.
* The SLB has 64 entries rather than 32.
* There is no mediated external interrupt facility, so if we switch to
a guest that has a virtual external interrupt pending but the guest
has MSR[EE] = 0, we have to arrange to have an interrupt pending for
it so that we can get control back once it re-enables interrupts. We
do that by sending ourselves an IPI with smp_send_reschedule after
hard-disabling interrupts.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
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architecture bits
This replaces the single CPU_FTR_HVMODE_206 bit with two bits, one to
indicate that we have a usable hypervisor mode, and another to indicate
that the processor conforms to PowerISA version 2.06. We also add
another bit to indicate that the processor conforms to ISA version 2.01
and set that for PPC970 and derivatives.
Some PPC970 chips (specifically those in Apple machines) have a
hypervisor mode in that MSR[HV] is always 1, but the hypervisor mode
is not useful in the sense that there is no way to run any code in
supervisor mode (HV=0 PR=0). On these processors, the LPES0 and LPES1
bits in HID4 are always 0, and we use that as a way of detecting that
hypervisor mode is not useful.
Where we have a feature section in assembly code around code that
only applies on POWER7 in hypervisor mode, we use a construct like
END_FTR_SECTION_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
The definition of END_FTR_SECTION_IFSET is such that the code will
be enabled (not overwritten with nops) only if all bits in the
provided mask are set.
Note that the CPU feature check in __tlbie() only needs to check the
ARCH_206 bit, not the HVMODE bit, because __tlbie() can only get called
if we are running bare-metal, i.e. in hypervisor mode.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
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This is used to round-robin TLBCAM entries.
Signed-off-by: Becky Bruce <beckyb@kernel.crashing.org>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
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The nmi parameter indicated if we could do wakeups from the current
context, if not, we would set some state and self-IPI and let the
resulting interrupt do the wakeup.
For the various event classes:
- hardware: nmi=0; PMI is in fact an NMI or we run irq_work_run from
the PMI-tail (ARM etc.)
- tracepoint: nmi=0; since tracepoint could be from NMI context.
- software: nmi=[0,1]; some, like the schedule thing cannot
perform wakeups, and hence need 0.
As one can see, there is very little nmi=1 usage, and the down-side of
not using it is that on some platforms some software events can have a
jiffy delay in wakeup (when arch_irq_work_raise isn't implemented).
The up-side however is that we can remove the nmi parameter and save a
bunch of conditionals in fast paths.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Michael Cree <mcree@orcon.net.nz>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Don Zickus <dzickus@redhat.com>
Link: http://lkml.kernel.org/n/tip-agjev8eu666tvknpb3iaj0fg@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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This patch adds a printk companion to replace the udbg progress function
when initmem is freed.
Suggested-by: Milton Miller <miltonm@bga.com>
Suggested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Dave Carroll <dcarroll@astekcorp.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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The free_initmem function is basically duplicated in mm/init_32,
and init_64, and is moved to the common 32/64-bit mm/mem.c.
All other sections except init were removed in v2.6.15 by
6c45ab992e4299c869fb26427944a8f8ea177024 (powerpc: Remove section
free() and linker script bits), and therefore the bulk of the executed
code is identical.
This patch also removes updating ppc_md.progress to NULL in the powermac
late_initcall.
Suggested-by: Milton Miller <miltonm@bga.com>
Suggested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Dave Carroll <dcarroll@astekcorp.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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This has been broken for a while but hasn't been an issue until
now because nobody was reserving regions at high addresses.
Signed-off-by: Becky Bruce <beckyb@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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On MMUs such as FSL where we can guarantee the entire linear mapping is
bolted, we don't need to worry about linear TLB misses. If on top of
that we do a full table walk, we get rid of all recursive TLB faults, and
can dispense with some state saving. This gains a few percent on
TLB-miss-heavy workloads, and around 50% on a benchmark that had a high
rate of virtual page table faults under the normal handler.
While touching the EX_TLB layout, remove EX_TLB_MMUCR0, EX_TLB_SRR0, and
EX_TLB_SRR1 as they're not used.
[BenH: Fixed build with 64K pages (wsp config)]
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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