commit 1524f4e47f upstream.
The "chip->dsp_spos_instance" can be NULL on some of the ealier error
paths in snd_cs46xx_create().
Reported-by: "Yavuz, Tuba" <tuba@ece.ufl.edu>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4bd46aa035 upstream.
It is reported that commit 95f408bbc4 ("media: cx23885: Ryzen DMA
related RiSC engine stall fixes") caused regresssions with other CPUs.
Ensure that the quirk will be applied only for the CPUs that
are known to cause problems.
A module option is added for explicit control of the behaviour.
Fixes: 95f408bbc4 ("media: cx23885: Ryzen DMA related RiSC engine stall fixes")
Signed-off-by: Brad Love <brad@nextdimension.cc>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7af7a8e19f upstream.
KSM pages may be mapped to the multiple VMAs that cannot be reached from
one anon_vma. So during swapin, a new copy of the page need to be
generated if a different anon_vma is needed, please refer to comments of
ksm_might_need_to_copy() for details.
During swapoff, unuse_vma() uses anon_vma (if available) to locate VMA and
virtual address mapped to the page, so not all mappings to a swapped out
KSM page could be found. So in try_to_unuse(), even if the swap count of
a swap entry isn't zero, the page needs to be deleted from swap cache, so
that, in the next round a new page could be allocated and swapin for the
other mappings of the swapped out KSM page.
But this contradicts with the THP swap support. Where the THP could be
deleted from swap cache only after the swap count of every swap entry in
the huge swap cluster backing the THP has reach 0. So try_to_unuse() is
changed in commit e07098294a ("mm, THP, swap: support to reclaim swap
space for THP swapped out") to check that before delete a page from swap
cache, but this has broken KSM swapoff too.
Fortunately, KSM is for the normal pages only, so the original behavior
for KSM pages could be restored easily via checking PageTransCompound().
That is how this patch works.
The bug is introduced by e07098294a ("mm, THP, swap: support to reclaim
swap space for THP swapped out"), which is merged by v4.14-rc1. So I
think we should backport the fix to from 4.14 on. But Hugh thinks it may
be rare for the KSM pages being in the swap device when swapoff, so nobody
reports the bug so far.
Link: http://lkml.kernel.org/r/20181226051522.28442-1-ying.huang@intel.com
Fixes: e07098294a ("mm, THP, swap: support to reclaim swap space for THP swapped out")
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reported-by: Hugh Dickins <hughd@google.com>
Tested-by: Hugh Dickins <hughd@google.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shaohua Li <shli@kernel.org>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 02917e9f86 upstream.
At Maintainer Summit, Greg brought up a topic I proposed around
EXPORT_SYMBOL_GPL usage. The motivation was considerations for when
EXPORT_SYMBOL_GPL is warranted and the criteria for taking the exceptional
step of reclassifying an existing export. Specifically, I wanted to make
the case that although the line is fuzzy and hard to specify in abstract
terms, it is nonetheless clear that devm_memremap_pages() and HMM
(Heterogeneous Memory Management) have crossed it. The
devm_memremap_pages() facility should have been EXPORT_SYMBOL_GPL from the
beginning, and HMM as a derivative of that functionality should have
naturally picked up that designation as well.
Contrary to typical rules, the HMM infrastructure was merged upstream with
zero in-tree consumers. There was a promise at the time that those users
would be merged "soon", but it has been over a year with no drivers
arriving. While the Nouveau driver is about to belatedly make good on
that promise it is clear that HMM was targeted first and foremost at an
out-of-tree consumer.
HMM is derived from devm_memremap_pages(), a facility Christoph and I
spearheaded to support persistent memory. It combines a device lifetime
model with a dynamically created 'struct page' / memmap array for any
physical address range. It enables coordination and control of the many
code paths in the kernel built to interact with memory via 'struct page'
objects. With HMM the integration goes even deeper by allowing device
drivers to hook and manipulate page fault and page free events.
One interpretation of when EXPORT_SYMBOL is suitable is when it is
exporting stable and generic leaf functionality. The
devm_memremap_pages() facility continues to see expanding use cases,
peer-to-peer DMA being the most recent, with no clear end date when it
will stop attracting reworks and semantic changes. It is not suitable to
export devm_memremap_pages() as a stable 3rd party driver API due to the
fact that it is still changing and manipulates core behavior. Moreover,
it is not in the best interest of the long term development of the core
memory management subsystem to permit any external driver to effectively
define its own system-wide memory management policies with no
encouragement to engage with upstream.
I am also concerned that HMM was designed in a way to minimize further
engagement with the core-MM. That, with these hooks in place,
device-drivers are free to implement their own policies without much
consideration for whether and how the core-MM could grow to meet that
need. Going forward not only should HMM be EXPORT_SYMBOL_GPL, but the
core-MM should be allowed the opportunity and stimulus to change and
address these new use cases as first class functionality.
Original changelog:
hmm_devmem_add(), and hmm_devmem_add_resource() duplicated
devm_memremap_pages() and are now simple now wrappers around the core
facility to inject a dev_pagemap instance into the global pgmap_radix and
hook page-idle events. The devm_memremap_pages() interface is base
infrastructure for HMM. HMM has more and deeper ties into the kernel
memory management implementation than base ZONE_DEVICE which is itself a
EXPORT_SYMBOL_GPL facility.
Originally, the HMM page structure creation routines copied the
devm_memremap_pages() code and reused ZONE_DEVICE. A cleanup to unify the
implementations was discussed during the initial review:
http://lkml.iu.edu/hypermail/linux/kernel/1701.2/00812.html Recent work to
extend devm_memremap_pages() for the peer-to-peer-DMA facility enabled
this cleanup to move forward.
In addition to the integration with devm_memremap_pages() HMM depends on
other GPL-only symbols:
mmu_notifier_unregister_no_release
percpu_ref
region_intersects
__class_create
It goes further to consume / indirectly expose functionality that is not
exported to any other driver:
alloc_pages_vma
walk_page_range
HMM is derived from devm_memremap_pages(), and extends deep core-kernel
fundamentals. Similar to devm_memremap_pages(), mark its entry points
EXPORT_SYMBOL_GPL().
[logang@deltatee.com: PCI/P2PDMA: match interface changes to devm_memremap_pages()]
Link: http://lkml.kernel.org/r/20181130225911.2900-1-logang@deltatee.com
Link: http://lkml.kernel.org/r/154275560565.76910.15919297436557795278.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Balbir Singh <bsingharora@gmail.com>,
Cc: Michal Hocko <mhocko@suse.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit bbecd94e6c upstream.
Commit e8d5134833 ("memremap: change devm_memremap_pages interface to
use struct dev_pagemap") refactored devm_memremap_pages() to allow a
dev_pagemap instance to be supplied. Passing in a dev_pagemap interface
simplifies the design of pgmap type drivers in that they can rely on
container_of() to lookup any private data associated with the given
dev_pagemap instance.
In addition to the cleanups this also gives hmm users multi-order-radix
improvements that arrived with commit ab1b597ee0 "mm,
devm_memremap_pages: use multi-order radix for ZONE_DEVICE lookups"
As part of the conversion to the devm_memremap_pages() method of
handling the percpu_ref relative to when pages are put, the percpu_ref
completion needs to move to hmm_devmem_ref_exit(). See 7138970383
("mm, zone_device: Replace {get, put}_zone_device_page...") for details.
Link: http://lkml.kernel.org/r/154275560053.76910.10870962637383152392.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jérôme Glisse <jglisse@redhat.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 58ef15b765 upstream.
devm semantics arrange for resources to be torn down when
device-driver-probe fails or when device-driver-release completes.
Similar to devm_memremap_pages() there is no need to support an explicit
remove operation when the users properly adhere to devm semantics.
Note that devm_kzalloc() automatically handles allocating node-local
memory.
Link: http://lkml.kernel.org/r/154275559545.76910.9186690723515469051.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jérôme Glisse <jglisse@redhat.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 69324b8f48 upstream.
In preparation for consolidating all ZONE_DEVICE enabling via
devm_memremap_pages(), teach it how to handle the constraints of
MEMORY_DEVICE_PRIVATE ranges.
[jglisse@redhat.com: call move_pfn_range_to_zone for MEMORY_DEVICE_PRIVATE]
Link: http://lkml.kernel.org/r/154275559036.76910.12434636179931292607.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Jérôme Glisse <jglisse@redhat.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Reported-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4ecd55ea07 upstream.
After commit d202cce896, an expired cache_head can be removed from the
cache_detail's hash.
However, the expired cache_head may be waiting for a reply from a
previously submitted request. Such a cache_head has an increased
refcounter and therefore it won't be freed after cache_put(freeme).
Because the cache_head was removed from the hash it cannot be found
during cache_clean() and can be leaked forever, together with stalled
cache_request and other taken resources.
In our case we noticed it because an entry in the export cache was
holding a reference on a filesystem.
Fixes d202cce896 ("sunrpc: never return expired entries in sunrpc_cache_lookup")
Cc: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Cc: stable@kernel.org # 2.6.35
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7056d3a37d upstream.
Burt Holzman has noticed that memcg v1 doesn't notify about OOM events via
eventfd anymore. The reason is that 29ef680ae7 ("memcg, oom: move
out_of_memory back to the charge path") has moved the oom handling back to
the charge path. While doing so the notification was left behind in
mem_cgroup_oom_synchronize.
Fix the issue by replicating the oom hierarchy locking and the
notification.
Link: http://lkml.kernel.org/r/20181224091107.18354-1-mhocko@kernel.org
Fixes: 29ef680ae7 ("memcg, oom: move out_of_memory back to the charge path")
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Burt Holzman <burt@fnal.gov>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com
Cc: <stable@vger.kernel.org> [4.19+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a95c90f1e2 upstream.
The last step before devm_memremap_pages() returns success is to allocate
a release action, devm_memremap_pages_release(), to tear the entire setup
down. However, the result from devm_add_action() is not checked.
Checking the error from devm_add_action() is not enough. The api
currently relies on the fact that the percpu_ref it is using is killed by
the time the devm_memremap_pages_release() is run. Rather than continue
this awkward situation, offload the responsibility of killing the
percpu_ref to devm_memremap_pages_release() directly. This allows
devm_memremap_pages() to do the right thing relative to init failures and
shutdown.
Without this change we could fail to register the teardown of
devm_memremap_pages(). The likelihood of hitting this failure is tiny as
small memory allocations almost always succeed. However, the impact of
the failure is large given any future reconfiguration, or disable/enable,
of an nvdimm namespace will fail forever as subsequent calls to
devm_memremap_pages() will fail to setup the pgmap_radix since there will
be stale entries for the physical address range.
An argument could be made to require that the ->kill() operation be set in
the @pgmap arg rather than passed in separately. However, it helps code
readability, tracking the lifetime of a given instance, to be able to grep
the kill routine directly at the devm_memremap_pages() call site.
Link: http://lkml.kernel.org/r/154275558526.76910.7535251937849268605.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Fixes: e8d5134833 ("memremap: change devm_memremap_pages interface...")
Reviewed-by: "Jérôme Glisse" <jglisse@redhat.com>
Reported-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 06489cfbd9 upstream.
Given the fact that devm_memremap_pages() requires a percpu_ref that is
torn down by devm_memremap_pages_release() the current support for mapping
RAM is broken.
Support for remapping "System RAM" has been broken since the beginning and
there is no existing user of this this code path, so just kill the support
and make it an explicit error.
This cleanup also simplifies a follow-on patch to fix the error path when
setting a devm release action for devm_memremap_pages_release() fails.
Link: http://lkml.kernel.org/r/154275557997.76910.14689813630968180480.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: "Jérôme Glisse" <jglisse@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 808153e118 upstream.
devm_memremap_pages() is a facility that can create struct page entries
for any arbitrary range and give drivers the ability to subvert core
aspects of page management.
Specifically the facility is tightly integrated with the kernel's memory
hotplug functionality. It injects an altmap argument deep into the
architecture specific vmemmap implementation to allow allocating from
specific reserved pages, and it has Linux specific assumptions about page
structure reference counting relative to get_user_pages() and
get_user_pages_fast(). It was an oversight and a mistake that this was
not marked EXPORT_SYMBOL_GPL from the outset.
Again, devm_memremap_pagex() exposes and relies upon core kernel internal
assumptions and will continue to evolve along with 'struct page', memory
hotplug, and support for new memory types / topologies. Only an in-kernel
GPL-only driver is expected to keep up with this ongoing evolution. This
interface, and functionality derived from this interface, is not suitable
for kernel-external drivers.
Link: http://lkml.kernel.org/r/154275557457.76910.16923571232582744134.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b15c87263a upstream.
We have received a bug report that an injected MCE about faulty memory
prevents memory offline to succeed on 4.4 base kernel. The underlying
reason was that the HWPoison page has an elevated reference count and the
migration keeps failing. There are two problems with that. First of all
it is dubious to migrate the poisoned page because we know that accessing
that memory is possible to fail. Secondly it doesn't make any sense to
migrate a potentially broken content and preserve the memory corruption
over to a new location.
Oscar has found out that 4.4 and the current upstream kernels behave
slightly differently with his simply testcase
===
int main(void)
{
int ret;
int i;
int fd;
char *array = malloc(4096);
char *array_locked = malloc(4096);
fd = open("/tmp/data", O_RDONLY);
read(fd, array, 4095);
for (i = 0; i < 4096; i++)
array_locked[i] = 'd';
ret = mlock((void *)PAGE_ALIGN((unsigned long)array_locked), sizeof(array_locked));
if (ret)
perror("mlock");
sleep (20);
ret = madvise((void *)PAGE_ALIGN((unsigned long)array_locked), 4096, MADV_HWPOISON);
if (ret)
perror("madvise");
for (i = 0; i < 4096; i++)
array_locked[i] = 'd';
return 0;
}
===
+ offline this memory.
In 4.4 kernels he saw the hwpoisoned page to be returned back to the LRU
list
kernel: [<ffffffff81019ac9>] dump_trace+0x59/0x340
kernel: [<ffffffff81019e9a>] show_stack_log_lvl+0xea/0x170
kernel: [<ffffffff8101ac71>] show_stack+0x21/0x40
kernel: [<ffffffff8132bb90>] dump_stack+0x5c/0x7c
kernel: [<ffffffff810815a1>] warn_slowpath_common+0x81/0xb0
kernel: [<ffffffff811a275c>] __pagevec_lru_add_fn+0x14c/0x160
kernel: [<ffffffff811a2eed>] pagevec_lru_move_fn+0xad/0x100
kernel: [<ffffffff811a334c>] __lru_cache_add+0x6c/0xb0
kernel: [<ffffffff81195236>] add_to_page_cache_lru+0x46/0x70
kernel: [<ffffffffa02b4373>] extent_readpages+0xc3/0x1a0 [btrfs]
kernel: [<ffffffff811a16d7>] __do_page_cache_readahead+0x177/0x200
kernel: [<ffffffff811a18c8>] ondemand_readahead+0x168/0x2a0
kernel: [<ffffffff8119673f>] generic_file_read_iter+0x41f/0x660
kernel: [<ffffffff8120e50d>] __vfs_read+0xcd/0x140
kernel: [<ffffffff8120e9ea>] vfs_read+0x7a/0x120
kernel: [<ffffffff8121404b>] kernel_read+0x3b/0x50
kernel: [<ffffffff81215c80>] do_execveat_common.isra.29+0x490/0x6f0
kernel: [<ffffffff81215f08>] do_execve+0x28/0x30
kernel: [<ffffffff81095ddb>] call_usermodehelper_exec_async+0xfb/0x130
kernel: [<ffffffff8161c045>] ret_from_fork+0x55/0x80
And that latter confuses the hotremove path because an LRU page is
attempted to be migrated and that fails due to an elevated reference
count. It is quite possible that the reuse of the HWPoisoned page is some
kind of fixed race condition but I am not really sure about that.
With the upstream kernel the failure is slightly different. The page
doesn't seem to have LRU bit set but isolate_movable_page simply fails and
do_migrate_range simply puts all the isolated pages back to LRU and
therefore no progress is made and scan_movable_pages finds same set of
pages over and over again.
Fix both cases by explicitly checking HWPoisoned pages before we even try
to get reference on the page, try to unmap it if it is still mapped. As
explained by Naoya:
: Hwpoison code never unmapped those for no big reason because
: Ksm pages never dominate memory, so we simply didn't have strong
: motivation to save the pages.
Also put WARN_ON(PageLRU) in case there is a race and we can hit LRU
HWPoison pages which shouldn't happen but I couldn't convince myself about
that. Naoya has noted the following:
: Theoretically no such gurantee, because try_to_unmap() doesn't have a
: guarantee of success and then memory_failure() returns immediately
: when hwpoison_user_mappings fails.
: Or the following code (comes after hwpoison_user_mappings block) also impli=
: es
: that the target page can still have PageLRU flag.
:
: /*
: * Torn down by someone else?
: */
: if (PageLRU(p) && !PageSwapCache(p) && p->mapping =3D=3D NULL) {
: action_result(pfn, MF_MSG_TRUNCATED_LRU, MF_IGNORED);
: res =3D -EBUSY;
: goto out;
: }
:
: So I think it's OK to keep "if (WARN_ON(PageLRU(page)))" block in
: current version of your patch.
Link: http://lkml.kernel.org/r/20181206120135.14079-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Oscar Salvador <osalvador@suse.com>
Debugged-by: Oscar Salvador <osalvador@suse.com>
Tested-by: Oscar Salvador <osalvador@suse.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7b55851367 upstream.
This changes the fork(2) syscall to record the process start_time after
initializing the basic task structure but still before making the new
process visible to user-space.
Technically, we could record the start_time anytime during fork(2). But
this might lead to scenarios where a start_time is recorded long before
a process becomes visible to user-space. For instance, with
userfaultfd(2) and TLS, user-space can delay the execution of fork(2)
for an indefinite amount of time (and will, if this causes network
access, or similar).
By recording the start_time late, it much closer reflects the point in
time where the process becomes live and can be observed by other
processes.
Lastly, this makes it much harder for user-space to predict and control
the start_time they get assigned. Previously, user-space could fork a
process and stall it in copy_thread_tls() before its pid is allocated,
but after its start_time is recorded. This can be misused to later-on
cycle through PIDs and resume the stalled fork(2) yielding a process
that has the same pid and start_time as a process that existed before.
This can be used to circumvent security systems that identify processes
by their pid+start_time combination.
Even though user-space was always aware that start_time recording is
flaky (but several projects are known to still rely on start_time-based
identification), changing the start_time to be recorded late will help
mitigate existing attacks and make it much harder for user-space to
control the start_time a process gets assigned.
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Tom Gundersen <teg@jklm.no>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4e87eb2f46 upstream.
Certain older adapters such as the OneConnect OCe10100 may not have a valid
wqpcnt value. In this case, do not set queue->page_count to 0 in
lpfc_sli4_queue_alloc() as this will prevent the driver from initializing.
Fixes: 895427bd01 ("scsi: lpfc: NVME Initiator: Base modifications")
Cc: stable@vger.kernel.org # 4.11+
Signed-off-by: Ewan D. Milne <emilne@redhat.com>
Reviewed-by: Laurence Oberman <loberman@redhat.com>
Tested-by: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 60a161b7e5 upstream.
Suppose adapter (open) recovery is between opened QDIO queues and before
(the end of) initial posting of status read buffers (SRBs). This time
window can be seconds long due to FSF_PROT_HOST_CONNECTION_INITIALIZING
causing by design looping with exponential increase sleeps in the function
performing exchange config data during recovery
[zfcp_erp_adapter_strat_fsf_xconf()]. Recovery triggered by local link up.
Suppose an event occurs for which the FCP channel would send an unsolicited
notification to zfcp by means of a previously posted SRB. We saw it with
local cable pull (link down) in multi-initiator zoning with multiple
NPIV-enabled subchannels of the same shared FCP channel.
As soon as zfcp_erp_adapter_strategy_open_fsf() starts posting the initial
status read buffers from within the adapter's ERP thread, the channel does
send an unsolicited notification.
Since v2.6.27 commit d26ab06ede ("[SCSI] zfcp: receiving an unsolicted
status can lead to I/O stall"), zfcp_fsf_status_read_handler() schedules
adapter->stat_work to re-fill the just consumed SRB from a work item.
Now the ERP thread and the work item post SRBs in parallel. Both contexts
call the helper function zfcp_status_read_refill(). The tracking of
missing (to be posted / re-filled) SRBs is not thread-safe due to separate
atomic_read() and atomic_dec(), in order to depend on posting
success. Hence, both contexts can see
atomic_read(&adapter->stat_miss) == 1. One of the two contexts posts
one too many SRB. Zfcp gets QDIO_ERROR_SLSB_STATE on the output queue
(trace tag "qdireq1") leading to zfcp_erp_adapter_shutdown() in
zfcp_qdio_handler_error().
An obvious and seemingly clean fix would be to schedule stat_work from the
ERP thread and wait for it to finish. This would serialize all SRB
re-fills. However, we already have another work item wait on the ERP
thread: adapter->scan_work runs zfcp_fc_scan_ports() which calls
zfcp_fc_eval_gpn_ft(). The latter calls zfcp_erp_wait() to wait for all the
open port recoveries during zfcp auto port scan, but in fact it waits for
any pending recovery including an adapter recovery. This approach leads to
a deadlock. [see also v3.19 commit 18f87a67e6 ("zfcp: auto port scan
resiliency"); v2.6.37 commit d3e1088d68
("[SCSI] zfcp: No ERP escalation on gpn_ft eval");
v2.6.28 commit fca55b6fb5
("[SCSI] zfcp: fix deadlock between wq triggered port scan and ERP")
fixing v2.6.27 commit c57a39a45a
("[SCSI] zfcp: wait until adapter is finished with ERP during auto-port");
v2.6.27 commit cc8c282963
("[SCSI] zfcp: Automatically attach remote ports")]
Instead make the accounting of missing SRBs atomic for parallel execution
in both the ERP thread and adapter->stat_work.
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Fixes: d26ab06ede ("[SCSI] zfcp: receiving an unsolicted status can lead to I/O stall")
Cc: <stable@vger.kernel.org> #2.6.27+
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 66a4059ba7 upstream.
MIPS' asm/mmzone.h includes the machine/platform mmzone.h
unconditionally, but since commit bb53fdf395 ("MIPS: c-r4k: Add
r4k_blast_scache_node for Loongson-3") is included by asm/rk4cache.h for
all r4k-style configs regardless of CONFIG_NEED_MULTIPLE_NODES.
This is problematic when CONFIG_NEED_MULTIPLE_NODES=n because both the
loongson3 & ip27 mmzone.h headers unconditionally define the NODE_DATA
preprocessor macro which is aready defined by linux/mmzone.h, resulting
in the following build error:
In file included from ./arch/mips/include/asm/mmzone.h:10,
from ./arch/mips/include/asm/r4kcache.h:23,
from arch/mips/mm/c-r4k.c:33:
./arch/mips/include/asm/mach-loongson64/mmzone.h:48: error: "NODE_DATA" redefined [-Werror]
#define NODE_DATA(n) (&__node_data[(n)]->pglist)
In file included from ./include/linux/topology.h:32,
from ./include/linux/irq.h:19,
from ./include/asm-generic/hardirq.h:13,
from ./arch/mips/include/asm/hardirq.h:16,
from ./include/linux/hardirq.h:9,
from arch/mips/mm/c-r4k.c:11:
./include/linux/mmzone.h:907: note: this is the location of the previous definition
#define NODE_DATA(nid) (&contig_page_data)
Resolve this by only including the machine mmzone.h when
CONFIG_NEED_MULTIPLE_NODES=y, which also removes the need for the empty
mach-generic version of the header which we delete.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Fixes: bb53fdf395 ("MIPS: c-r4k: Add r4k_blast_scache_node for Loongson-3")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 01f54664a4 upstream.
First, rename out_no_locality to out_locality for bailing out on
both tpm_cmd_ready() and tpm_request_locality() failure.
Second, ignore the return value of go_to_idle() as it may override
the return value of the actual tpm operation, the go_to_idle() error
will be caught on any consequent command.
Last, fix the wrong 'goto out', that jumped back instead of forward.
Cc: stable@vger.kernel.org
Fixes: 627448e85c ("tpm: separate cmd_ready/go_idle from runtime_pm")
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit dfbaecb2b7 upstream.
The alternative coding patch for parisc in kernel 4.20 broke booting
machines with PA8500-PA8700 CPUs. The problem is, that for such machines
the parisc kernel automatically utilizes huge pages to access kernel
text code, but the set_kernel_text_rw() function, which is used shortly
before applying any alternative patches, didn't used the correctly
hugepage-aligned addresses to remap the kernel text read-writeable.
Fixes: 3847dab774 ("parisc: Add alternative coding infrastructure")
Cc: <stable@vger.kernel.org> [4.20]
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5329043214 upstream.
The syscall number may have been changed by a tracer, so we should pass
the actual number in from the caller instead of pulling it from the
saved r7 value directly.
Cc: <stable@vger.kernel.org>
Cc: Pi-Hsun Shih <pihsun@chromium.org>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 169113ece0 upstream.
The ARM Linux kernel handles the EABI syscall numbers as follows:
0 - NR_SYSCALLS-1 : Invoke syscall via syscall table
NR_SYSCALLS - 0xeffff : -ENOSYS (to be allocated in future)
0xf0000 - 0xf07ff : Private syscall or -ENOSYS if not allocated
> 0xf07ff : SIGILL
Our compat code gets this wrong and ends up sending SIGILL in response
to all syscalls greater than NR_SYSCALLS which have a value greater
than 0x7ff in the bottom 16 bits.
Fix this by defining the end of the ARM private syscall region and
checking the syscall number against that directly. Update the comment
while we're at it.
Cc: <stable@vger.kernel.org>
Cc: Dave Martin <Dave.Martin@arm.com>
Reported-by: Pi-Hsun Shih <pihsun@chromium.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3cd508a8c1 upstream.
When we insert the sync sequence number into the CMD_SYNC.MSIData field,
we do so in CPU-native byte order, before writing out the whole command
as explicitly little-endian dwords. Thus on big-endian systems, the SMMU
will receive and write back a byteswapped version of sync_nr, which would
be perfect if it were targeting a similarly-little-endian ITS, but since
it's actually writing back to memory being polled by the CPUs, they're
going to end up seeing the wrong thing.
Since the SMMU doesn't care what the MSIData actually contains, the
minimal-overhead solution is to simply add an extra byteswap initially,
such that it then writes back the big-endian format directly.
Cc: <stable@vger.kernel.org>
Fixes: 37de98f8f1 ("iommu/arm-smmu-v3: Use CMD_SYNC completion MSI")
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c23b2e6fc4 upstream.
When using the nospec API, it should be taken into account that:
"...if the CPU speculates past the bounds check then
* array_index_nospec() will clamp the index within the range of [0,
* size)."
The above is part of the header for macro array_index_nospec() in
linux/nospec.h
Now, in this particular case, if intid evaluates to exactly VGIC_MAX_SPI
or to exaclty VGIC_MAX_PRIVATE, the array_index_nospec() macro ends up
returning VGIC_MAX_SPI - 1 or VGIC_MAX_PRIVATE - 1 respectively, instead
of VGIC_MAX_SPI or VGIC_MAX_PRIVATE, which, based on the original logic:
/* SGIs and PPIs */
if (intid <= VGIC_MAX_PRIVATE)
return &vcpu->arch.vgic_cpu.private_irqs[intid];
/* SPIs */
if (intid <= VGIC_MAX_SPI)
return &kvm->arch.vgic.spis[intid - VGIC_NR_PRIVATE_IRQS];
are valid values for intid.
Fix this by calling array_index_nospec() macro with VGIC_MAX_PRIVATE + 1
and VGIC_MAX_SPI + 1 as arguments for its parameter size.
Fixes: 41b87599c7 ("KVM: arm/arm64: vgic: fix possible spectre-v1 in vgic_get_irq()")
Cc: stable@vger.kernel.org
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
[dropped the SPI part which was fixed separately]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit fb544d1ca6 upstream.
We recently addressed a VMID generation race by introducing a read/write
lock around accesses and updates to the vmid generation values.
However, kvm_arch_vcpu_ioctl_run() also calls need_new_vmid_gen() but
does so without taking the read lock.
As far as I can tell, this can lead to the same kind of race:
VM 0, VCPU 0 VM 0, VCPU 1
------------ ------------
update_vttbr (vmid 254)
update_vttbr (vmid 1) // roll over
read_lock(kvm_vmid_lock);
force_vm_exit()
local_irq_disable
need_new_vmid_gen == false //because vmid gen matches
enter_guest (vmid 254)
kvm_arch.vttbr = <PGD>:<VMID 1>
read_unlock(kvm_vmid_lock);
enter_guest (vmid 1)
Which results in running two VCPUs in the same VM with different VMIDs
and (even worse) other VCPUs from other VMs could now allocate clashing
VMID 254 from the new generation as long as VCPU 0 is not exiting.
Attempt to solve this by making sure vttbr is updated before another CPU
can observe the updated VMID generation.
Cc: stable@vger.kernel.org
Fixes: f0cf47d939 "KVM: arm/arm64: Close VMID generation race"
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 60c3ab30d8 upstream.
When restoring the active state from userspace, we don't know which CPU
was the source for the active state, and this is not architecturally
exposed in any of the register state.
Set the active_source to 0 in this case. In the future, we can expand
on this and exposse the information as additional information to
userspace for GICv2 if anyone cares.
Cc: stable@vger.kernel.org
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit bea2ef803a upstream.
SPIs should be checked against the VMs specific configuration, and
not the architectural maximum.
Cc: stable@vger.kernel.org
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2e2f6c3c0b upstream.
To change the active state of an MMIO, halt is requested for all vcpus of
the affected guest before modifying the IRQ state. This is done by calling
cond_resched_lock() in vgic_mmio_change_active(). However interrupts are
disabled at this point and we cannot reschedule a vcpu.
We actually don't need any of this, as kvm_arm_halt_guest ensures that
all the other vcpus are out of the guest. Let's just drop that useless
code.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Suggested-by: Christoffer Dall <christoffer.dall@arm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3cc9ffbb1f upstream.
Add the missing adjustment of the month range on alarm reads from the
RTC, correcting an issue coming from commit 9c6dfed92c ("rtc: m41t80:
add alarm functionality"). The range is 1-12 for hardware and 0-11 for
`struct rtc_time', and is already correctly handled on alarm writes to
the RTC.
It was correct up until commit 48e9766726 ("drivers/rtc/rtc-m41t80.c:
remove disabled alarm functionality") too, which removed the previous
implementation of alarm support.
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Fixes: 9c6dfed92c ("rtc: m41t80: add alarm functionality")
References: 48e9766726 ("drivers/rtc/rtc-m41t80.c: remove disabled alarm functionality")
Cc: stable@vger.kernel.org # 4.7+
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8ac686d7df upstream.
The assigned parent clocks should be normally specified in the consumer
device's DT node, this ensures respective driver always sees correct clock
settings when required.
This patch fixes regression in audio subsystem on Odroid XU3/XU4 boards
that appeared after commits:
commit 647d04f8e0 ("ASoC: samsung: i2s: Ensure the RCLK rate is properly determined")
commit 995e73e55f ("ASoC: samsung: i2s: Fix rclk_srcrate handling")
commit 48279c53fd ("ASoC: samsung: i2s: Prevent external abort on exynos5433 I2S1 access")
Without this patch the driver gets wrong clock as the I2S function clock
(op_clk) in probe() and effectively the clock which is finally assigned
from DT is not being enabled/disabled in the runtime resume/suspend ops.
Without the above listed commits the EXYNOS_I2S_BUS clock was always set
as parent of CLK_I2S_RCLK_SRC regardless of DT settings so there was no issue
with not enabled EXYNOS_SCLK_I2S.
Cc: <stable@vger.kernel.org> # 4.17.x
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 107352a249 upstream.
We currently only halt the guest when a vCPU messes with the active
state of an SPI. This is perfectly fine for GICv2, but isn't enough
for GICv3, where all vCPUs can access the state of any other vCPU.
Let's broaden the condition to include any GICv3 interrupt that
has an active state (i.e. all but LPIs).
Cc: stable@vger.kernel.org
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit df655b75c4 upstream.
Although bit 31 of VTCR_EL2 is RES1, we inadvertently end up setting all
of the upper 32 bits to 1 as well because we define VTCR_EL2_RES1 as
signed, which is sign-extended when assigning to kvm->arch.vtcr.
Lucky for us, the architecture currently treats these upper bits as RES0
so, whilst we've been naughty, we haven't set fire to anything yet.
Cc: <stable@vger.kernel.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b6bc8a7b99 upstream.
The current code attempts to pin memory using the largest possible wsize
based on the currect SMB credits. This doesn't cause kernel oops but this
is not optimal as we may pin more pages then actually needed.
Fix this by only pinning what are needed for doing this write I/O.
Signed-off-by: Long Li <longli@microsoft.com>
Cc: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Joey Pabalinas <joeypabalinas@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 54e94ff94e upstream.
When pinning memory failed, we should return the correct error code and
rewind the SMB credits.
Reported-by: Murphy Zhou <jencce.kernel@gmail.com>
Signed-off-by: Long Li <longli@microsoft.com>
Cc: stable@vger.kernel.org
Cc: Murphy Zhou <jencce.kernel@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6d2f84eee0 upstream.
When passing a large read to receive_encrypted_read(), ensure that the
demultiplex_thread knows that a MID was processed. Without this, those
operations never complete.
This is a similar issue/fix to lease break handling:
commit 7af929d6d0
("smb3: fix lease break problem introduced by compounding")
CC: Stable <stable@vger.kernel.org> # 4.19+
Fixes: b24df3e30c ("cifs: update receive_encrypted_standard to handle compounded responses")
Signed-off-by: Paul Aurich <paul@darkrain42.org>
Tested-by: Yves-Alexis Perez <corsac@corsac.net>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9a596f5b39 upstream.
While resolving a bug with locks on samba shares found a strange behavior.
When a file locked by one node and we trying to lock it from another node
it fail with errno 5 (EIO) but in that case errno must be set to
(EACCES | EAGAIN).
This isn't happening when we try to lock file second time on same node.
In this case it returns EACCES as expected.
Also this issue not reproduces when we use SMB1 protocol (vers=1.0 in
mount options).
Further investigation showed that the mapping from status_to_posix_error
is different for SMB1 and SMB2+ implementations.
For SMB1 mapping is [NT_STATUS_LOCK_NOT_GRANTED to ERRlock]
(See fs/cifs/netmisc.c line 66)
but for SMB2+ mapping is [STATUS_LOCK_NOT_GRANTED to -EIO]
(see fs/cifs/smb2maperror.c line 383)
Quick changes in SMB2+ mapping from EIO to EACCES has fixed issue.
BUG: https://bugzilla.kernel.org/show_bug.cgi?id=201971
Signed-off-by: Georgy A Bystrenin <gkot@altlinux.org>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit edefae94b7 upstream.
Commit 885872b722 ("MIPS: Octeon: Add Octeon III CN7xxx
interface detection") added RGMII interface detection for OCTEON III,
but it results in the following logs:
[ 7.165984] ERROR: Unsupported Octeon model in __cvmx_helper_rgmii_probe
[ 7.173017] ERROR: Unsupported Octeon model in __cvmx_helper_rgmii_probe
The current RGMII routines are valid only for older OCTEONS that
use GMX/ASX hardware blocks. On later chips AGL should be used,
but support for that is missing in the mainline. Until that is added,
mark the interface as disabled.
Fixes: 885872b722 ("MIPS: Octeon: Add Octeon III CN7xxx interface detection")
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: stable@vger.kernel.org # 4.7+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ff4dd232ec upstream.
ASIDs have always been stored as unsigned longs, ie. 32 bits on MIPS32
kernels. This is problematic because it is feasible for the ASID version
to overflow & wrap around to zero.
We currently attempt to handle this overflow by simply setting the ASID
version to 1, using asid_first_version(), but we make no attempt to
account for the fact that there may be mm_structs with stale ASIDs that
have versions which we now reuse due to the overflow & wrap around.
Encountering this requires that:
1) A struct mm_struct X is active on CPU A using ASID (V,n).
2) That mm is not used on CPU A for the length of time that it takes
for CPU A's asid_cache to overflow & wrap around to the same
version V that the mm had in step 1. During this time tasks using
the mm could either be sleeping or only scheduled on other CPUs.
3) Some other mm Y becomes active on CPU A and is allocated the same
ASID (V,n).
4) mm X now becomes active on CPU A again, and now incorrectly has the
same ASID as mm Y.
Where struct mm_struct ASIDs are represented above in the format
(version, EntryHi.ASID), and on a typical MIPS32 system version will be
24 bits wide & EntryHi.ASID will be 8 bits wide.
The length of time required in step 2 is highly dependent upon the CPU &
workload, but for a hypothetical 2GHz CPU running a workload which
generates a new ASID every 10000 cycles this period is around 248 days.
Due to this long period of time & the fact that tasks need to be
scheduled in just the right (or wrong, depending upon your inclination)
way, this is obviously a difficult bug to encounter but it's entirely
possible as evidenced by reports.
In order to fix this, simply extend ASIDs to 64 bits even on MIPS32
builds. This will extend the period of time required for the
hypothetical system above to encounter the problem from 28 days to
around 3 trillion years, which feels safely outside of the realms of
possibility.
The cost of this is slightly more generated code in some commonly
executed paths, but this is pretty minimal:
| Code Size Gain | Percentage
-----------------------|----------------|-------------
decstation_defconfig | +270 | +0.00%
32r2el_defconfig | +652 | +0.01%
32r6el_defconfig | +1000 | +0.01%
I have been unable to measure any change in performance of the LMbench
lat_ctx or lat_proc tests resulting from the 64b ASIDs on either
32r2el_defconfig+interAptiv or 32r6el_defconfig+I6500 systems.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Suggested-by: James Hogan <jhogan@kernel.org>
References: https://lore.kernel.org/linux-mips/80B78A8B8FEE6145A87579E8435D78C30205D5F3@fzex.ruijie.com.cn/
References: https://lore.kernel.org/linux-mips/1488684260-18867-1-git-send-email-jiwei.sun@windriver.com/
Cc: Jiwei Sun <jiwei.sun@windriver.com>
Cc: Yu Huabing <yhb@ruijie.com.cn>
Cc: stable@vger.kernel.org # 2.6.12+
Cc: linux-mips@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit bec0de4cfa upstream.
KEXEC needs the new kernel's load address to be aligned on a page
boundary (see sanity_check_segment_list()), but on MIPS the default
vmlinuz load address is only explicitly aligned to 16 bytes.
Since the largest PAGE_SIZE supported by MIPS kernels is 64KB, increase
the alignment calculated by calc_vmlinuz_load_addr to 64KB.
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21131/
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <james.hogan@mips.com>
Cc: Steven J . Hill <Steven.Hill@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: <stable@vger.kernel.org> # 2.6.36+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit bb53fdf395 upstream.
For multi-node Loongson-3 (NUMA configuration), r4k_blast_scache() can
only flush Node-0's scache. So we add r4k_blast_scache_node() by using
(CAC_BASE | (node_id << NODE_ADDRSPACE_SHIFT)) instead of CKSEG0 as the
start address.
Signed-off-by: Huacai Chen <chenhc@lemote.com>
[paul.burton@mips.com: Include asm/mmzone.h from asm/r4kcache.h for
nid_to_addrbase(). Add asm/mach-generic/mmzone.h
to allow inclusion for all platforms.]
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21129/
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <james.hogan@mips.com>
Cc: Steven J . Hill <Steven.Hill@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: <stable@vger.kernel.org> # 3.15+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit adcc81f148 upstream.
Mapping the delay slot emulation page as both writeable & executable
presents a security risk, in that if an exploit can write to & jump into
the page then it can be used as an easy way to execute arbitrary code.
Prevent this by mapping the page read-only for userland, and using
access_process_vm() with the FOLL_FORCE flag to write to it from
mips_dsemul().
This will likely be less efficient due to copy_to_user_page() performing
cache maintenance on a whole page, rather than a single line as in the
previous use of flush_cache_sigtramp(). However this delay slot
emulation code ought not to be running in any performance critical paths
anyway so this isn't really a problem, and we can probably do better in
copy_to_user_page() anyway in future.
A major advantage of this approach is that the fix is small & simple to
backport to stable kernels.
Reported-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Fixes: 432c6bacbd ("MIPS: Use per-mm page to execute branch delay slot instructions")
Cc: stable@vger.kernel.org # v4.8+
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Rich Felker <dalias@libc.org>
Cc: David Daney <david.daney@cavium.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f024cf085c upstream.
In the case that a bprintk event has a dereferenced pointer that is
stored as a string, and there's more values to process (more args), the
arg was not updated to point to the next arg after processing the
dereferenced pointer, and it screwed up what was to be displayed.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linux-trace-devel@vger.kernel.org
Cc: stable@vger.kernel.org
Fixes: 37db96bb49 ("tools lib traceevent: Handle new pointer processing of bprint strings")
Link: http://lkml.kernel.org/r/20181210134522.3f71e2ca@gandalf.local.home
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit fa09d06522 upstream.
When parallel bus is used and data-active is being parsed, incorrect
flags are cleared.
Clear the correct flag bits.
Fixes: e9be1b863e (media: v4l: fwnode:
Use default parallel flags).
Cc: stable@vger.kernel.org # for Kernel 4.20
Signed-off-by: Ondrej Jirman <megous@megous.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e5f71a27fa upstream.
text[s] is a signed char, so using that as index into the font8x16 array
can result in negative indices. Cast it to u8 to be safe.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Reported-by: syzbot+ccf0a61ed12f2a7313ee@syzkaller.appspotmail.com
Cc: <stable@vger.kernel.org> # for v4.7 and up
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
