Add the functionality, is_raw_hwpoison_page_in_hugepage, to tell if a raw
page in a hugetlb folio is HWPOISON. This functionality relies on
RawHwpUnreliable to be not set; otherwise hugepage's raw HWPOISON list
becomes meaningless.
is_raw_hwpoison_page_in_hugepage holds mf_mutex in order to synchronize
with folio_set_hugetlb_hwpoison and folio_free_raw_hwp who iterate,
insert, or delete entry in raw_hwp_list. llist itself doesn't ensure
insertion and removal are synchornized with the llist_for_each_entry used
by is_raw_hwpoison_page_in_hugepage (unless iterated entries are already
deleted from the list). Caller can minimize the overhead of lock cycles
by first checking HWPOISON flag of the folio.
Exports this functionality to be immediately used in the read operation
for hugetlbfs.
Link: https://lkml.kernel.org/r/20230713001833.3778937-3-jiaqiyan@google.com
Signed-off-by: Jiaqi Yan <jiaqiyan@google.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The basic idea here is to "simulate" memory poisoning for VMs. A VM
running on some host might encounter a memory error, after which some
page(s) are poisoned (i.e., future accesses SIGBUS). They expect that
once poisoned, pages can never become "un-poisoned". So, when we live
migrate the VM, we need to preserve the poisoned status of these pages.
When live migrating, we try to get the guest running on its new host as
quickly as possible. So, we start it running before all memory has been
copied, and before we're certain which pages should be poisoned or not.
So the basic way to use this new feature is:
- On the new host, the guest's memory is registered with userfaultfd, in
either MISSING or MINOR mode (doesn't really matter for this purpose).
- On any first access, we get a userfaultfd event. At this point we can
communicate with the old host to find out if the page was poisoned.
- If so, we can respond with a UFFDIO_POISON - this places a swap marker
so any future accesses will SIGBUS. Because the pte is now "present",
future accesses won't generate more userfaultfd events, they'll just
SIGBUS directly.
UFFDIO_POISON does not handle unmapping previously-present PTEs. This
isn't needed, because during live migration we want to intercept all
accesses with userfaultfd (not just writes, so WP mode isn't useful for
this). So whether minor or missing mode is being used (or both), the PTE
won't be present in any case, so handling that case isn't needed.
Similarly, UFFDIO_POISON won't replace existing PTE markers. This might
be okay to do, but it seems to be safer to just refuse to overwrite any
existing entry (like a UFFD_WP PTE marker).
Link: https://lkml.kernel.org/r/20230707215540.2324998-5-axelrasmussen@google.com
Signed-off-by: Axel Rasmussen <axelrasmussen@google.com>
Acked-by: Peter Xu <peterx@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Gaosheng Cui <cuigaosheng1@huawei.com>
Cc: Huang, Ying <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Jan Alexander Steffens (heftig) <heftig@archlinux.org>
Cc: Jiaqi Yan <jiaqiyan@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nadav Amit <namit@vmware.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suleiman Souhlal <suleiman@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: T.J. Alumbaugh <talumbau@google.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: ZhangPeng <zhangpeng362@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "add UFFDIO_POISON to simulate memory poisoning with UFFD",
v4.
This series adds a new userfaultfd feature, UFFDIO_POISON. See commit 4
for a detailed description of the feature.
This patch (of 8):
Future patches will reuse PTE_MARKER_SWAPIN_ERROR to implement
UFFDIO_POISON, so make some various preparations for that:
First, rename it to just PTE_MARKER_POISONED. The "SWAPIN" can be
confusing since we're going to re-use it for something not really related
to swap. This can be particularly confusing for things like hugetlbfs,
which doesn't support swap whatsoever. Also rename some various helper
functions.
Next, fix pte marker copying for hugetlbfs. Previously, it would WARN on
seeing a PTE_MARKER_SWAPIN_ERROR, since hugetlbfs doesn't support swap.
But, since we're going to re-use it, we want it to go ahead and copy it
just like non-hugetlbfs memory does today. Since the code to do this is
more complicated now, pull it out into a helper which can be re-used in
both places. While we're at it, also make it slightly more explicit in
its handling of e.g. uffd wp markers.
For non-hugetlbfs page faults, instead of returning VM_FAULT_SIGBUS for an
error entry, return VM_FAULT_HWPOISON. For most cases this change doesn't
matter, e.g. a userspace program would receive a SIGBUS either way. But
for UFFDIO_POISON, this change will let KVM guests get an MCE out of the
box, instead of giving a SIGBUS to the hypervisor and requiring it to
somehow inject an MCE.
Finally, for hugetlbfs faults, handle PTE_MARKER_POISONED, and return
VM_FAULT_HWPOISON_LARGE in such cases. Note that this can't happen today
because the lack of swap support means we'll never end up with such a PTE
anyway, but this behavior will be needed once such entries *can* show up
via UFFDIO_POISON.
Link: https://lkml.kernel.org/r/20230707215540.2324998-1-axelrasmussen@google.com
Link: https://lkml.kernel.org/r/20230707215540.2324998-2-axelrasmussen@google.com
Signed-off-by: Axel Rasmussen <axelrasmussen@google.com>
Acked-by: Peter Xu <peterx@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Gaosheng Cui <cuigaosheng1@huawei.com>
Cc: Huang, Ying <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Jan Alexander Steffens (heftig) <heftig@archlinux.org>
Cc: Jiaqi Yan <jiaqiyan@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nadav Amit <namit@vmware.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suleiman Souhlal <suleiman@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: T.J. Alumbaugh <talumbau@google.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: ZhangPeng <zhangpeng362@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Fscache has an optimisation by which reads from the cache are skipped
until we know that (a) there's data there to be read and (b) that data
isn't entirely covered by pages resident in the netfs pagecache. This is
done with two flags manipulated by fscache_note_page_release():
if (...
test_bit(FSCACHE_COOKIE_HAVE_DATA, &cookie->flags) &&
test_bit(FSCACHE_COOKIE_NO_DATA_TO_READ, &cookie->flags))
clear_bit(FSCACHE_COOKIE_NO_DATA_TO_READ, &cookie->flags);
where the NO_DATA_TO_READ flag causes cachefiles_prepare_read() to
indicate that netfslib should download from the server or clear the page
instead.
The fscache_note_page_release() function is intended to be called from
->releasepage() - but that only gets called if PG_private or PG_private_2
is set - and currently the former is at the discretion of the network
filesystem and the latter is only set whilst a page is being written to
the cache, so sometimes we miss clearing the optimisation.
Fix this by following Willy's suggestion[1] and adding an address_space
flag, AS_RELEASE_ALWAYS, that causes filemap_release_folio() to always call
->release_folio() if it's set, even if PG_private or PG_private_2 aren't
set.
Note that this would require folio_test_private() and page_has_private() to
become more complicated. To avoid that, in the places[*] where these are
used to conditionalise calls to filemap_release_folio() and
try_to_release_page(), the tests are removed the those functions just
jumped to unconditionally and the test is performed there.
[*] There are some exceptions in vmscan.c where the check guards more than
just a call to the releaser. I've added a function, folio_needs_release()
to wrap all the checks for that.
AS_RELEASE_ALWAYS should be set if a non-NULL cookie is obtained from
fscache and cleared in ->evict_inode() before truncate_inode_pages_final()
is called.
Additionally, the FSCACHE_COOKIE_NO_DATA_TO_READ flag needs to be cleared
and the optimisation cancelled if a cachefiles object already contains data
when we open it.
[dwysocha@redhat.com: call folio_mapping() inside folio_needs_release()]
Link: 902c990e31
Link: https://lkml.kernel.org/r/20230628104852.3391651-3-dhowells@redhat.com
Fixes: 1f67e6d0b1 ("fscache: Provide a function to note the release of a page")
Fixes: 047487c947 ("cachefiles: Implement the I/O routines")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Reported-by: Rohith Surabattula <rohiths.msft@gmail.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Tested-by: SeongJae Park <sj@kernel.org>
Cc: Daire Byrne <daire.byrne@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Steve French <sfrench@samba.org>
Cc: Shyam Prasad N <nspmangalore@gmail.com>
Cc: Rohith Surabattula <rohiths.msft@gmail.com>
Cc: Dave Wysochanski <dwysocha@redhat.com>
Cc: Dominique Martinet <asmadeus@codewreck.org>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Jingbo Xu <jefflexu@linux.alibaba.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
As the number of ksm zero pages is not included in ksm_merging_pages per
process when enabling use_zero_pages, it's unclear of how many actual
pages are merged by KSM. To let users accurately estimate their memory
demands when unsharing KSM zero-pages, it's necessary to show KSM zero-
pages per process. In addition, it help users to know the actual KSM
profit because KSM-placed zero pages are also benefit from KSM.
since unsharing zero pages placed by KSM accurately is achieved, then
tracking empty pages merging and unmerging is not a difficult thing any
longer.
Since we already have /proc/<pid>/ksm_stat, just add the information of
'ksm_zero_pages' in it.
Link: https://lkml.kernel.org/r/20230613030938.185993-1-yang.yang29@zte.com.cn
Signed-off-by: xu xin <xu.xin16@zte.com.cn>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Xiaokai Ran <ran.xiaokai@zte.com.cn>
Reviewed-by: Yang Yang <yang.yang29@zte.com.cn>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Xuexin Jiang <jiang.xuexin@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
As pages_sharing and pages_shared don't include the number of zero pages
merged by KSM, we cannot know how many pages are zero pages placed by KSM
when enabling use_zero_pages, which leads to KSM not being transparent
with all actual merged pages by KSM. In the early days of use_zero_pages,
zero-pages was unable to get unshared by the ways like MADV_UNMERGEABLE so
it's hard to count how many times one of those zeropages was then
unmerged.
But now, unsharing KSM-placed zero page accurately has been achieved, so
we can easily count both how many times a page full of zeroes was merged
with zero-page and how many times one of those pages was then unmerged.
and so, it helps to estimate memory demands when each and every shared
page could get unshared.
So we add ksm_zero_pages under /sys/kernel/mm/ksm/ to show the number
of all zero pages placed by KSM. Meanwhile, we update the Documentation.
Link: https://lkml.kernel.org/r/20230613030934.185944-1-yang.yang29@zte.com.cn
Signed-off-by: xu xin <xu.xin16@zte.com.cn>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Xuexin Jiang <jiang.xuexin@zte.com.cn>
Reviewed-by: Xiaokai Ran <ran.xiaokai@zte.com.cn>
Reviewed-by: Yang Yang <yang.yang29@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "ksm: support tracking KSM-placed zero-pages", v10.
The core idea of this patch set is to enable users to perceive the number
of any pages merged by KSM, regardless of whether use_zero_page switch has
been turned on, so that users can know how much free memory increase is
really due to their madvise(MERGEABLE) actions. But the problem is, when
enabling use_zero_pages, all empty pages will be merged with kernel zero
pages instead of with each other as use_zero_pages is disabled, and then
these zero-pages are no longer monitored by KSM.
The motivations to do this is seen at:
https://lore.kernel.org/lkml/202302100915227721315@zte.com.cn/
In one word, we hope to implement the support for KSM-placed zero pages
tracking without affecting the feature of use_zero_pages, so that app
developer can also benefit from knowing the actual KSM profit by getting
KSM-placed zero pages to optimize applications eventually when
/sys/kernel/mm/ksm/use_zero_pages is enabled.
This patch (of 5):
When use_zero_pages of ksm is enabled, madvise(addr, len,
MADV_UNMERGEABLE) and other ways (like write 2 to /sys/kernel/mm/ksm/run)
to trigger unsharing will *not* actually unshare the shared zeropage as
placed by KSM (which is against the MADV_UNMERGEABLE documentation). As
these KSM-placed zero pages are out of the control of KSM, the related
counts of ksm pages don't expose how many zero pages are placed by KSM
(these special zero pages are different from those initially mapped zero
pages, because the zero pages mapped to MADV_UNMERGEABLE areas are
expected to be a complete and unshared page).
To not blindly unshare all shared zero_pages in applicable VMAs, the patch
use pte_mkdirty (related with architecture) to mark KSM-placed zero pages.
Thus, MADV_UNMERGEABLE will only unshare those KSM-placed zero pages.
In addition, we'll reuse this mechanism to reliably identify KSM-placed
ZeroPages to properly account for them (e.g., calculating the KSM profit
that includes zeropages) in the latter patches.
The patch will not degrade the performance of use_zero_pages as it doesn't
change the way of merging empty pages in use_zero_pages's feature.
Link: https://lkml.kernel.org/r/202306131104554703428@zte.com.cn
Link: https://lkml.kernel.org/r/20230613030928.185882-1-yang.yang29@zte.com.cn
Signed-off-by: xu xin <xu.xin16@zte.com.cn>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Xuexin Jiang <jiang.xuexin@zte.com.cn>
Reviewed-by: Xiaokai Ran <ran.xiaokai@zte.com.cn>
Reviewed-by: Yang Yang <yang.yang29@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The documentation of mt_next() claims that it starts the search at the
provided index. That's incorrect as it starts the search after the
provided index.
The documentation of mt_find() is slightly confusing. "Handles locking"
is not really helpful as it does not explain how the "locking" works.
Also the documentation of index talks about a range, while in reality the
index is updated on a succesful search to the index of the found entry
plus one.
Fix similar issues for mt_find_after() and mt_prev().
Reword the confusing "Note: Will not return the zero entry." comment on
mt_for_each() and document @__index correctly.
Link: https://lkml.kernel.org/r/87ttw2n556.ffs@tglx
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Shanker Donthineni <sdonthineni@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pull smb client fixes from Steve French:
"Four small SMB3 client fixes:
- two reconnect fixes (to address the case where non-default
iocharset gets incorrectly overridden at reconnect with the
default charset)
- fix for NTLMSSP_AUTH request setting a flag incorrectly)
- Add missing check for invalid tlink (tree connection) in ioctl"
* tag '6.5-rc3-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
cifs: add missing return value check for cifs_sb_tlink
smb3: do not set NTLMSSP_VERSION flag for negotiate not auth request
cifs: fix charset issue in reconnection
fs/nls: make load_nls() take a const parameter
Pull tracing fixes from Steven Rostedt:
- Fix to /sys/kernel/tracing/per_cpu/cpu*/stats read and entries.
If a resize shrinks the buffer it clears the read count to notify
readers that they need to reset. But the read count is also used for
accounting and this causes the numbers to be off. Instead, create a
separate variable to use to notify readers to reset.
- Fix the ref counts of the "soft disable" mode. The wrong value was
used for testing if soft disable mode should be enabled or disable,
but instead, just change the logic to do the enable and disable in
place when the SOFT_MODE is set or cleared.
- Several kernel-doc fixes
- Removal of unused external declarations
* tag 'trace-v6.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: Fix warning in trace_buffered_event_disable()
ftrace: Remove unused extern declarations
tracing: Fix kernel-doc warnings in trace_seq.c
tracing: Fix kernel-doc warnings in trace_events_trigger.c
tracing/synthetic: Fix kernel-doc warnings in trace_events_synth.c
ring-buffer: Fix kernel-doc warnings in ring_buffer.c
ring-buffer: Fix wrong stat of cpu_buffer->read
Pull hotfixes from Andrew Morton:
"11 hotfixes. Five are cc:stable and the remainder address post-6.4
issues or aren't considered serious enough to justify backporting"
* tag 'mm-hotfixes-stable-2023-07-28-15-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
mm/memory-failure: fix hardware poison check in unpoison_memory()
proc/vmcore: fix signedness bug in read_from_oldmem()
mailmap: update remaining active codeaurora.org email addresses
mm: lock VMA in dup_anon_vma() before setting ->anon_vma
mm: fix memory ordering for mm_lock_seq and vm_lock_seq
scripts/spelling.txt: remove 'thead' as a typo
mm/pagewalk: fix EFI_PGT_DUMP of espfix area
shmem: minor fixes to splice-read implementation
tmpfs: fix Documentation of noswap and huge mount options
Revert "um: Use swap() to make code cleaner"
mm/damon/core-test: initialise context before test in damon_test_set_attrs()
Pull thermal control fixes from Rafael Wysocki:
"Constify thermal_zone_device_register() parameters, which was omitted
by mistake, and fix a double free on thermal zone unregistration in
the generic DT thermal driver (Ahmad Fatoum)"
* tag 'thermal-6.5-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
thermal: of: fix double-free on unregistration
thermal: core: constify params in thermal_zone_device_register
Pull power management fixes from Rafael Wysocki:
"Fix the arming of wakeup IRQs in the generic wakeup IRQ code
(wakeirq), drop unused functions from it and fix up a driver using it
and trying to work around the IRQ arming issue in a questionable way
(Johan Hovold)"
* tag 'pm-6.5-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
serial: qcom-geni: drop bogus runtime pm state update
PM: sleep: wakeirq: drop unused enable helpers
PM: sleep: wakeirq: fix wake irq arming
Pull xen fixes from Juergen Gross:
- A fix for a performance problem in QubesOS, adding a way to drain the
queue of grants experiencing delayed unmaps faster
- A patch enabling the use of static event channels from user mode,
which was omitted when introducing supporting static event channels
- A fix for a problem where Xen related code didn't check properly for
running in a Xen environment, resulting in a WARN splat
* tag 'for-linus-6.5a-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen: speed up grant-table reclaim
xen/evtchn: Introduce new IOCTL to bind static evtchn
xenbus: check xen_domain in xenbus_probe_initcall
Pull block fixes from Jens Axboe:
"A few fixes that should go into the current kernel release, mainly:
- Set of fixes for dasd (Stefan)
- Handle interruptible waits returning because of a signal for ublk
(Ming)"
* tag 'block-6.5-2023-07-28' of git://git.kernel.dk/linux:
ublk: return -EINTR if breaking from waiting for existed users in DEL_DEV
ublk: fail to recover device if queue setup is interrupted
ublk: fail to start device if queue setup is interrupted
block: Fix a source code comment in include/uapi/linux/blkzoned.h
s390/dasd: print copy pair message only for the correct error
s390/dasd: fix hanging device after request requeue
s390/dasd: use correct number of retries for ERP requests
s390/dasd: fix hanging device after quiesce/resume
Pull drm fixes from Dave Airlie:
"Regular scheduled fixes, msm and amdgpu leading the way, with some
i915 and a single misc fbdev, all seems fine.
fbdev:
- remove unused function
amdgpu:
- gfxhub partition fix
- Fix error handling in psp_sw_init()
- SMU13 fix
- DCN 3.1 fix
- DCN 3.2 fix
- Fix for display PHY programming sequence
- DP MST error handling fix
- GFX 9.4.3 fix
amdkfd:
- GFX11 trap handling fix
i915:
- Use shmem for dpt objects
- Fix an error handling path in igt_write_huge()
msm:
- display:
- Fix to correct the UBWC programming for decoder version 4.3 seen
on SM8550
- Add the missing flush and fetch bits for DMA4 and DMA5 SSPPs.
- Fix to drop the unused dpu_core_perf_data_bus_id enum from the
code
- Drop the unused dsi_phy_14nm_17mA_regulators from QCM 2290 DSI
cfg.
- gpu:
- Fix warn splat for newer devices without revn
- Remove name/revn for a690.. we shouldn't be populating these for
newer devices, for consistency, but it slipped through review
- Fix a6xx gpu snapshot BINDLESS_DATA size (was listed in bytes
instead of dwords, causing AHB faults on a6xx gen4/a660-family)
- Disallow submit with fence id 0"
* tag 'drm-fixes-2023-07-28' of git://anongit.freedesktop.org/drm/drm: (22 commits)
drm/msm: Disallow submit with fence id 0
drm/amdgpu: Restore HQD persistent state register
drm/amd/display: Unlock on error path in dm_handle_mst_sideband_msg_ready_event()
drm/amd/display: Exit idle optimizations before attempt to access PHY
drm/amd/display: Don't apply FIFO resync W/A if rdivider = 0
drm/amd/display: Guard DCN31 PHYD32CLK logic against chip family
drm/amd/smu: use AverageGfxclkFrequency* to replace previous GFX Curr Clock
drm/amd: Fix an error handling mistake in psp_sw_init()
drm/amdgpu: Fix infinite loop in gfxhub_v1_2_xcc_gart_enable (v2)
drm/amdkfd: fix trap handling work around for debugging
drm/fb-helper: Remove unused inline function drm_fb_helper_defio_init()
drm/i915: Fix an error handling path in igt_write_huge()
drm/i915/dpt: Use shmem for dpt objects
drm/msm: Fix hw_fence error path cleanup
drm/msm: Fix IS_ERR_OR_NULL() vs NULL check in a5xx_submit_in_rb()
drm/msm/adreno: Fix snapshot BINDLESS_DATA size
drm/msm/a690: Remove revn and name
drm/msm/adreno: Fix warn splat for devices without revn
drm/msm/dsi: Drop unused regulators from QCM2290 14nm DSI PHY config
drm/msm/dpu: drop enum dpu_core_perf_data_bus_id
...
mm->mm_lock_seq effectively functions as a read/write lock; therefore it
must be used with acquire/release semantics.
A specific example is the interaction between userfaultfd_register() and
lock_vma_under_rcu().
userfaultfd_register() does the following from the point where it changes
a VMA's flags to the point where concurrent readers are permitted again
(in a simple scenario where only a single private VMA is accessed and no
merging/splitting is involved):
userfaultfd_register
userfaultfd_set_vm_flags
vm_flags_reset
vma_start_write
down_write(&vma->vm_lock->lock)
vma->vm_lock_seq = mm_lock_seq [marks VMA as busy]
up_write(&vma->vm_lock->lock)
vm_flags_init
[sets VM_UFFD_* in __vm_flags]
vma->vm_userfaultfd_ctx.ctx = ctx
mmap_write_unlock
vma_end_write_all
WRITE_ONCE(mm->mm_lock_seq, mm->mm_lock_seq + 1) [unlocks VMA]
There are no memory barriers in between the __vm_flags update and the
mm->mm_lock_seq update that unlocks the VMA, so the unlock can be
reordered to above the `vm_flags_init()` call, which means from the
perspective of a concurrent reader, a VMA can be marked as a userfaultfd
VMA while it is not VMA-locked. That's bad, we definitely need a
store-release for the unlock operation.
The non-atomic write to vma->vm_lock_seq in vma_start_write() is mostly
fine because all accesses to vma->vm_lock_seq that matter are always
protected by the VMA lock. There is a racy read in vma_start_read()
though that can tolerate false-positives, so we should be using
WRITE_ONCE() to keep things tidy and data-race-free (including for KCSAN).
On the other side, lock_vma_under_rcu() works as follows in the relevant
region for locking and userfaultfd check:
lock_vma_under_rcu
vma_start_read
vma->vm_lock_seq == READ_ONCE(vma->vm_mm->mm_lock_seq) [early bailout]
down_read_trylock(&vma->vm_lock->lock)
vma->vm_lock_seq == READ_ONCE(vma->vm_mm->mm_lock_seq) [main check]
userfaultfd_armed
checks vma->vm_flags & __VM_UFFD_FLAGS
Here, the interesting aspect is how far down the mm->mm_lock_seq read can
be reordered - if this read is reordered down below the vma->vm_flags
access, this could cause lock_vma_under_rcu() to partly operate on
information that was read while the VMA was supposed to be locked. To
prevent this kind of downwards bleeding of the mm->mm_lock_seq read, we
need to read it with a load-acquire.
Some of the comment wording is based on suggestions by Suren.
BACKPORT WARNING: One of the functions changed by this patch (which I've
written against Linus' tree) is vma_try_start_write(), but this function
no longer exists in mm/mm-everything. I don't know whether the merged
version of this patch will be ordered before or after the patch that
removes vma_try_start_write(). If you're backporting this patch to a tree
with vma_try_start_write(), make sure this patch changes that function.
Link: https://lkml.kernel.org/r/20230721225107.942336-1-jannh@google.com
Fixes: 5e31275cc9 ("mm: add per-VMA lock and helper functions to control it")
Signed-off-by: Jann Horn <jannh@google.com>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pull networking fixes from Paolo Abeni:
"Including fixes from can, netfilter.
Current release - regressions:
- core: fix splice_to_socket() for O_NONBLOCK socket
- af_unix: fix fortify_panic() in unix_bind_bsd().
- can: raw: fix lockdep issue in raw_release()
Previous releases - regressions:
- tcp: reduce chance of collisions in inet6_hashfn().
- netfilter: skip immediate deactivate in _PREPARE_ERROR
- tipc: stop tipc crypto on failure in tipc_node_create
- eth: igc: fix kernel panic during ndo_tx_timeout callback
- eth: iavf: fix potential deadlock on allocation failure
Previous releases - always broken:
- ipv6: fix bug where deleting a mngtmpaddr can create a new
temporary address
- eth: ice: fix memory management in ice_ethtool_fdir.c
- eth: hns3: fix the imp capability bit cannot exceed 32 bits issue
- eth: vxlan: calculate correct header length for GPE
- eth: stmmac: apply redundant write work around on 4.xx too"
* tag 'net-6.5-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (49 commits)
tipc: stop tipc crypto on failure in tipc_node_create
af_unix: Terminate sun_path when bind()ing pathname socket.
tipc: check return value of pskb_trim()
benet: fix return value check in be_lancer_xmit_workarounds()
virtio-net: fix race between set queues and probe
net/sched: mqprio: Add length check for TCA_MQPRIO_{MAX/MIN}_RATE64
splice, net: Fix splice_to_socket() for O_NONBLOCK socket
net: fec: tx processing does not call XDP APIs if budget is 0
mptcp: more accurate NL event generation
selftests: mptcp: join: only check for ip6tables if needed
tools: ynl-gen: fix parse multi-attr enum attribute
tools: ynl-gen: fix enum index in _decode_enum(..)
netfilter: nf_tables: disallow rule addition to bound chain via NFTA_RULE_CHAIN_ID
netfilter: nf_tables: skip immediate deactivate in _PREPARE_ERROR
netfilter: nft_set_rbtree: fix overlap expiration walk
igc: Fix Kernel Panic during ndo_tx_timeout callback
net: dsa: qca8k: fix mdb add/del case with 0 VID
net: dsa: qca8k: fix broken search_and_del
net: dsa: qca8k: fix search_and_insert wrong handling of new rule
net: dsa: qca8k: enable use_single_write for qca8xxx
...
Xen 4.17 supports the creation of static evtchns. To allow user space
application to bind static evtchns introduce new ioctl
"IOCTL_EVTCHN_BIND_STATIC". Existing IOCTL doing more than binding
that’s why we need to introduce the new IOCTL to only bind the static
event channels.
Static evtchns to be available for use during the lifetime of the
guest. When the application exits, __unbind_from_irq() ends up being
called from release() file operations because of that static evtchns
are getting closed. To avoid closing the static event channel, add the
new bool variable "is_static" in "struct irq_info" to mark the event
channel static when creating the event channel to avoid closing the
static evtchn.
Also, take this opportunity to remove the open-coded version of the
evtchn close in drivers/xen/evtchn.c file and use xen_evtchn_close().
Signed-off-by: Rahul Singh <rahul.singh@arm.com>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Link: https://lore.kernel.org/r/ae7329bf1713f83e4aad4f3fa0f316258c40a3e9.1689677042.git.rahul.singh@arm.com
Signed-off-by: Juergen Gross <jgross@suse.com>
load_nls() take a char * parameter, use it to find nls module in list or
construct the module name to load it.
This change make load_nls() take a const parameter, so we don't need do
some cast like this:
ses->local_nls = load_nls((char *)ctx->local_nls->charset);
Suggested-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Winston Wen <wentao@uniontech.com>
Reviewed-by: Paulo Alcantara <pc@manguebit.com>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
