| Age | Commit message (Collapse) | Author |
|---|
|
The x86 Control-flow Enforcement Technology (CET) feature includes a
new type of memory called shadow stack. This shadow stack memory has
some unusual properties, which requires some core mm changes to
function properly.
In userspace, shadow stack memory is writable only in very specific,
controlled ways. However, since userspace can, even in the limited
ways, modify shadow stack contents, the kernel treats it as writable
memory. As a result, without additional work there would remain many
ways for userspace to trigger the kernel to write arbitrary data to
shadow stacks via get_user_pages(, FOLL_WRITE) based operations. To
help userspace protect their shadow stacks, make this a little less
exposed by blocking writable get_user_pages() operations for shadow
stack VMAs.
Still allow FOLL_FORCE to write through shadow stack protections, as it
does for read-only protections. This is required for debugging use
cases.
[ dhansen: fix rebase goof, readd writable_file_mapping_allowed() hunk ]
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Tested-by: Pengfei Xu <pengfei.xu@intel.com>
Tested-by: John Allen <john.allen@amd.com>
Tested-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/all/20230613001108.3040476-23-rick.p.edgecombe%40intel.com
|
|
The x86 Control-flow Enforcement Technology (CET) feature includes a new
type of memory called shadow stack. This shadow stack memory has some
unusual properties, which requires some core mm changes to function
properly.
Co-developed-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Tested-by: Pengfei Xu <pengfei.xu@intel.com>
Tested-by: John Allen <john.allen@amd.com>
Tested-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/all/20230613001108.3040476-20-rick.p.edgecombe%40intel.com
|
|
The x86 Control-flow Enforcement Technology (CET) feature includes a new
type of memory called shadow stack. This shadow stack memory has some
unusual properties, which requires some core mm changes to function
properly.
One sharp edge is that PTEs that are both Write=0 and Dirty=1 are
treated as shadow by the CPU, but this combination used to be created by
the kernel on x86. Previous patches have changed the kernel to now avoid
creating these PTEs unless they are for shadow stack memory. In case any
missed corners of the kernel are still creating PTEs like this for
non-shadow stack memory, and to catch any re-introductions of the logic,
warn if any shadow stack PTEs (Write=0, Dirty=1) are found in non-shadow
stack VMAs when they are being zapped. This won't catch transient cases
but should have decent coverage.
In order to check if a PTE is shadow stack in core mm code, add two arch
breakouts arch_check_zapped_pte/pmd(). This will allow shadow stack
specific code to be kept in arch/x86.
Only do the check if shadow stack is supported by the CPU and configured
because in rare cases older CPUs may write Dirty=1 to a Write=0 CPU on
older CPUs. This check is handled in pte_shstk()/pmd_shstk().
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Tested-by: Pengfei Xu <pengfei.xu@intel.com>
Tested-by: John Allen <john.allen@amd.com>
Tested-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/all/20230613001108.3040476-18-rick.p.edgecombe%40intel.com
|
|
The x86 Control-flow Enforcement Technology (CET) feature includes a new
type of memory called shadow stack. This shadow stack memory has some
unusual properties, which requires some core mm changes to function
properly.
The architecture of shadow stack constrains the ability of userspace to
move the shadow stack pointer (SSP) in order to prevent corrupting or
switching to other shadow stacks. The RSTORSSP instruction can move the
SSP to different shadow stacks, but it requires a specially placed token
in order to do this. However, the architecture does not prevent
incrementing the stack pointer to wander onto an adjacent shadow stack. To
prevent this in software, enforce guard pages at the beginning of shadow
stack VMAs, such that there will always be a gap between adjacent shadow
stacks.
Make the gap big enough so that no userspace SSP changing operations
(besides RSTORSSP), can move the SSP from one stack to the next. The
SSP can be incremented or decremented by CALL, RET and INCSSP. CALL and
RET can move the SSP by a maximum of 8 bytes, at which point the shadow
stack would be accessed.
The INCSSP instruction can also increment the shadow stack pointer. It
is the shadow stack analog of an instruction like:
addq $0x80, %rsp
However, there is one important difference between an ADD on %rsp and
INCSSP. In addition to modifying SSP, INCSSP also reads from the memory
of the first and last elements that were "popped". It can be thought of
as acting like this:
READ_ONCE(ssp); // read+discard top element on stack
ssp += nr_to_pop * 8; // move the shadow stack
READ_ONCE(ssp-8); // read+discard last popped stack element
The maximum distance INCSSP can move the SSP is 2040 bytes, before it
would read the memory. Therefore, a single page gap will be enough to
prevent any operation from shifting the SSP to an adjacent stack, since
it would have to land in the gap at least once, causing a fault.
This could be accomplished by using VM_GROWSDOWN, but this has a
downside. The behavior would allow shadow stacks to grow, which is
unneeded and adds a strange difference to how most regular stacks work.
In the maple tree code, there is some logic for retrying the unmapped
area search if a guard gap is violated. This retry should happen for
shadow stack guard gap violations as well. This logic currently only
checks for VM_GROWSDOWN for start gaps. Since shadow stacks also have
a start gap as well, create an new define VM_STARTGAP_FLAGS to hold
all the VM flag bits that have start gaps, and make mmap use it.
Co-developed-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Tested-by: Pengfei Xu <pengfei.xu@intel.com>
Tested-by: John Allen <john.allen@amd.com>
Tested-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/all/20230613001108.3040476-17-rick.p.edgecombe%40intel.com
|
|
There was no more caller passing vm_flags to do_mmap(), and vm_flags was
removed from the function's input by:
commit 45e55300f114 ("mm: remove unnecessary wrapper function do_mmap_pgoff()").
There is a new user now. Shadow stack allocation passes VM_SHADOW_STACK to
do_mmap(). Thus, re-introduce vm_flags to do_mmap().
Co-developed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Tested-by: Pengfei Xu <pengfei.xu@intel.com>
Tested-by: John Allen <john.allen@amd.com>
Tested-by: Kees Cook <keescook@chromium.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/all/20230613001108.3040476-5-rick.p.edgecombe%40intel.com
|
|
The x86 Shadow stack feature includes a new type of memory called shadow
stack. This shadow stack memory has some unusual properties, which requires
some core mm changes to function properly.
One of these unusual properties is that shadow stack memory is writable,
but only in limited ways. These limits are applied via a specific PTE
bit combination. Nevertheless, the memory is writable, and core mm code
will need to apply the writable permissions in the typical paths that
call pte_mkwrite(). Future patches will make pte_mkwrite() take a VMA, so
that the x86 implementation of it can know whether to create regular
writable or shadow stack mappings.
But there are a couple of challenges to this. Modifying the signatures of
each arch pte_mkwrite() implementation would be error prone because some
are generated with macros and would need to be re-implemented. Also, some
pte_mkwrite() callers operate on kernel memory without a VMA.
So this can be done in a three step process. First pte_mkwrite() can be
renamed to pte_mkwrite_novma() in each arch, with a generic pte_mkwrite()
added that just calls pte_mkwrite_novma(). Next callers without a VMA can
be moved to pte_mkwrite_novma(). And lastly, pte_mkwrite() and all callers
can be changed to take/pass a VMA.
Previous work pte_mkwrite() renamed pte_mkwrite_novma() and converted
callers that don't have a VMA were to use pte_mkwrite_novma(). So now
change pte_mkwrite() to take a VMA and change the remaining callers to
pass a VMA. Apply the same changes for pmd_mkwrite().
No functional change.
Suggested-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/all/20230613001108.3040476-4-rick.p.edgecombe%40intel.com
|
|
Lockdep is certainly right to complain about
(&vma->vm_lock->lock){++++}-{3:3}, at: vma_start_write+0x2d/0x3f
but task is already holding lock:
(&mapping->i_mmap_rwsem){+.+.}-{3:3}, at: mmap_region+0x4dc/0x6db
Invert those to the usual ordering.
Fixes: 33313a747e81 ("mm: lock newly mapped VMA which can be modified after it becomes visible")
Cc: stable@vger.kernel.org
Signed-off-by: Hugh Dickins <hughd@google.com>
Tested-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull hotfixes from Andrew Morton:
"16 hotfixes. Six are cc:stable and the remainder address post-6.4
issues"
The merge undoes the disabling of the CONFIG_PER_VMA_LOCK feature, since
it was all hopefully fixed in mainline.
* tag 'mm-hotfixes-stable-2023-07-08-10-43' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
lib: dhry: fix sleeping allocations inside non-preemptable section
kasan, slub: fix HW_TAGS zeroing with slub_debug
kasan: fix type cast in memory_is_poisoned_n
mailmap: add entries for Heiko Stuebner
mailmap: update manpage link
bootmem: remove the vmemmap pages from kmemleak in free_bootmem_page
MAINTAINERS: add linux-next info
mailmap: add Markus Schneider-Pargmann
writeback: account the number of pages written back
mm: call arch_swap_restore() from do_swap_page()
squashfs: fix cache race with migration
mm/hugetlb.c: fix a bug within a BUG(): inconsistent pte comparison
docs: update ocfs2-devel mailing list address
MAINTAINERS: update ocfs2-devel mailing list address
mm: disable CONFIG_PER_VMA_LOCK until its fixed
fork: lock VMAs of the parent process when forking
|
|
mmap_region adds a newly created VMA into VMA tree and might modify it
afterwards before dropping the mmap_lock. This poses a problem for page
faults handled under per-VMA locks because they don't take the mmap_lock
and can stumble on this VMA while it's still being modified. Currently
this does not pose a problem since post-addition modifications are done
only for file-backed VMAs, which are not handled under per-VMA lock.
However, once support for handling file-backed page faults with per-VMA
locks is added, this will become a race.
Fix this by write-locking the VMA before inserting it into the VMA tree.
Other places where a new VMA is added into VMA tree do not modify it
after the insertion, so do not need the same locking.
Cc: stable@vger.kernel.org
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
With recent changes necessitating mmap_lock to be held for write while
expanding a stack, per-VMA locks should follow the same rules and be
write-locked to prevent page faults into the VMA being expanded. Add
the necessary locking.
Cc: stable@vger.kernel.org
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Commit 946fa0dbf2d8 ("mm/slub: extend redzone check to extra allocated
kmalloc space than requested") added precise kmalloc redzone poisoning to
the slub_debug functionality.
However, this commit didn't account for HW_TAGS KASAN fully initializing
the object via its built-in memory initialization feature. Even though
HW_TAGS KASAN memory initialization contains special memory initialization
handling for when slub_debug is enabled, it does not account for in-object
slub_debug redzones. As a result, HW_TAGS KASAN can overwrite these
redzones and cause false-positive slub_debug reports.
To fix the issue, avoid HW_TAGS KASAN memory initialization when
slub_debug is enabled altogether. Implement this by moving the
__slub_debug_enabled check to slab_post_alloc_hook. Common slab code
seems like a more appropriate place for a slub_debug check anyway.
Link: https://lkml.kernel.org/r/678ac92ab790dba9198f9ca14f405651b97c8502.1688561016.git.andreyknvl@google.com
Fixes: 946fa0dbf2d8 ("mm/slub: extend redzone check to extra allocated kmalloc space than requested")
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reported-by: Will Deacon <will@kernel.org>
Acked-by: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: kasan-dev@googlegroups.com
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Commit bb6e04a173f0 ("kasan: use internal prototypes matching gcc-13
builtins") introduced a bug into the memory_is_poisoned_n implementation:
it effectively removed the cast to a signed integer type after applying
KASAN_GRANULE_MASK.
As a result, KASAN started failing to properly check memset, memcpy, and
other similar functions.
Fix the bug by adding the cast back (through an additional signed integer
variable to make the code more readable).
Link: https://lkml.kernel.org/r/8c9e0251c2b8b81016255709d4ec42942dcaf018.1688431866.git.andreyknvl@google.com
Fixes: bb6e04a173f0 ("kasan: use internal prototypes matching gcc-13 builtins")
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
nr_to_write is a count of pages, so we need to decrease it by the number
of pages in the folio we just wrote, not by 1. Most callers specify
either LONG_MAX or 1, so are unaffected, but writeback_sb_inodes() might
end up writing 512x as many pages as it asked for.
Dave added:
: XFS is the only filesystem this would affect, right? AFAIA, nothing
: else enables large folios and uses writeback through
: write_cache_pages() at this point...
:
: In which case, I'd be surprised if much difference, if any, gets
: noticed by anyone.
Link: https://lkml.kernel.org/r/20230628185548.981888-1-willy@infradead.org
Fixes: 793917d997df ("mm/readahead: Add large folio readahead")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jan Kara <jack@suse.cz>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Commit c145e0b47c77 ("mm: streamline COW logic in do_swap_page()") moved
the call to swap_free() before the call to set_pte_at(), which meant that
the MTE tags could end up being freed before set_pte_at() had a chance to
restore them. Fix it by adding a call to the arch_swap_restore() hook
before the call to swap_free().
Link: https://lkml.kernel.org/r/20230523004312.1807357-2-pcc@google.com
Link: https://linux-review.googlesource.com/id/I6470efa669e8bd2f841049b8c61020c510678965
Fixes: c145e0b47c77 ("mm: streamline COW logic in do_swap_page()")
Signed-off-by: Peter Collingbourne <pcc@google.com>
Reported-by: Qun-wei Lin <Qun-wei.Lin@mediatek.com>
Closes: https://lore.kernel.org/all/5050805753ac469e8d727c797c2218a9d780d434.camel@mediatek.com/
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: <stable@vger.kernel.org> [6.1+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The following crash happens for me when running the -mm selftests (below).
Specifically, it happens while running the uffd-stress subtests:
kernel BUG at mm/hugetlb.c:7249!
invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
CPU: 0 PID: 3238 Comm: uffd-stress Not tainted 6.4.0-hubbard-github+ #109
Hardware name: ASUS X299-A/PRIME X299-A, BIOS 1503 08/03/2018
RIP: 0010:huge_pte_alloc+0x12c/0x1a0
...
Call Trace:
<TASK>
? __die_body+0x63/0xb0
? die+0x9f/0xc0
? do_trap+0xab/0x180
? huge_pte_alloc+0x12c/0x1a0
? do_error_trap+0xc6/0x110
? huge_pte_alloc+0x12c/0x1a0
? handle_invalid_op+0x2c/0x40
? huge_pte_alloc+0x12c/0x1a0
? exc_invalid_op+0x33/0x50
? asm_exc_invalid_op+0x16/0x20
? __pfx_put_prev_task_idle+0x10/0x10
? huge_pte_alloc+0x12c/0x1a0
hugetlb_fault+0x1a3/0x1120
? finish_task_switch+0xb3/0x2a0
? lock_is_held_type+0xdb/0x150
handle_mm_fault+0xb8a/0xd40
? find_vma+0x5d/0xa0
do_user_addr_fault+0x257/0x5d0
exc_page_fault+0x7b/0x1f0
asm_exc_page_fault+0x22/0x30
That happens because a BUG() statement in huge_pte_alloc() attempts to
check that a pte, if present, is a hugetlb pte, but it does so in a
non-lockless-safe manner that leads to a false BUG() report.
We got here due to a couple of bugs, each of which by itself was not quite
enough to cause a problem:
First of all, before commit c33c794828f2("mm: ptep_get() conversion"), the
BUG() statement in huge_pte_alloc() was itself fragile: it relied upon
compiler behavior to only read the pte once, despite using it twice in the
same conditional.
Next, commit c33c794828f2 ("mm: ptep_get() conversion") broke that
delicate situation, by causing all direct pte reads to be done via
READ_ONCE(). And so READ_ONCE() got called twice within the same BUG()
conditional, leading to comparing (potentially, occasionally) different
versions of the pte, and thus to false BUG() reports.
Fix this by taking a single snapshot of the pte before using it in the
BUG conditional.
Now, that commit is only partially to blame here but, people doing
bisections will invariably land there, so this will help them find a fix
for a real crash. And also, the previous behavior was unlikely to ever
expose this bug--it was fragile, yet not actually broken.
So that's why I chose this commit for the Fixes tag, rather than the
commit that created the original BUG() statement.
Link: https://lkml.kernel.org/r/20230701010442.2041858-1-jhubbard@nvidia.com
Fixes: c33c794828f2 ("mm: ptep_get() conversion")
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: James Houghton <jthoughton@google.com>
Acked-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Dimitri Sivanich <dimitri.sivanich@hpe.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: SeongJae Park <sj@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
A memory corruption was reported in [1] with bisection pointing to the
patch [2] enabling per-VMA locks for x86. Disable per-VMA locks config to
prevent this issue until the fix is confirmed. This is expected to be a
temporary measure.
[1] https://bugzilla.kernel.org/show_bug.cgi?id=217624
[2] https://lore.kernel.org/all/20230227173632.3292573-30-surenb@google.com
Link: https://lkml.kernel.org/r/20230706011400.2949242-3-surenb@google.com
Reported-by: Jiri Slaby <jirislaby@kernel.org>
Closes: https://lore.kernel.org/all/dbdef34c-3a07-5951-e1ae-e9c6e3cdf51b@kernel.org/
Reported-by: Jacob Young <jacobly.alt@gmail.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217624
Fixes: 0bff0aaea03e ("x86/mm: try VMA lock-based page fault handling first")
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Holger Hoffstätte <holger@applied-asynchrony.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
I added a warning about about GUP no longer expanding the stack in
commit a425ac5365f6 ("gup: add warning if some caller would seem to want
stack expansion"), but didn't really expect anybody to hit it.
And it's true that nobody seems to have hit a _real_ case yet, but we
certainly have a number of reports of false positives. Which not only
causes extra noise in itself, but might also end up hiding any real
cases if they do exist.
So let's tighten up the warning condition, and replace the simplistic
vma = find_vma(mm, start);
if (vma && (start < vma->vm_start)) {
WARN_ON_ONCE(vma->vm_flags & VM_GROWSDOWN);
with a
vma = gup_vma_lookup(mm, start);
helper function which works otherwise like just "vma_lookup()", but with
some heuristics for when to warn about gup no longer causing stack
expansion.
In particular, don't just warn for "below the stack", but warn if it's
_just_ below the stack (with "just below" arbitrarily defined as 64kB,
because why not?). And rate-limit it to at most once per hour, which
means that any false positives shouldn't completely hide subsequent
reports, but we won't be flooding the logs about it either.
The previous code triggered when some GUP user (chromium crashpad)
accessing past the end of the previous vma, for example. That has never
expanded the stack, it just causes GUP to return early, and as such we
shouldn't be warning about it.
This is still going trigger the randomized testers, but to mitigate the
noise from that, use "dump_stack()" instead of "WARN_ON_ONCE()" to get
the kernel call chain. We'll get the relevant information, but syzbot
shouldn't get too upset about it.
Also, don't even bother with the GROWSUP case, which would be using
different heuristics entirely, but only happens on parisc.
Reported-by: kernel test robot <oliver.sang@intel.com>
Reported-by: John Hubbard <jhubbard@nvidia.com>
Reported-by: syzbot+6cf44e127903fdf9d929@syzkaller.appspotmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
This is an addition to commit ae80b4041984 ("mm: validate the mm before
dropping the mmap lock"), because it turns out there were two problems,
but lockdep just stopped complaining after finding the first one.
The do_vmi_align_munmap() function now drops the mmap lock after doing
the validate_mm() call, but it turns out that one of the callers then
immediately calls validate_mm() again.
That's both a bit silly, and now (again) happens without the mmap lock
held.
So just remove that validate_mm() call from the caller, but make sure to
not lose any coverage by doing that mm sanity checking in the error path
of do_vmi_align_munmap() too.
Reported-and-tested-by: kernel test robot <oliver.sang@intel.com>
Link: https://lore.kernel.org/lkml/ZKN6CdkKyxBShPHi@xsang-OptiPlex-9020/
Fixes: 408579cd627a ("mm: Update do_vmi_align_munmap() return semantics")
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Commit 408579cd627a ("mm: Update do_vmi_align_munmap() return
semantics") made the return value and locking semantics of
do_vmi_align_munmap() more straightforward, but in the process it ended
up unlocking the mmap lock just a tad too early: the debug code doing
the mmap layout validation still needs to run with the lock held, or
things might change under it while it's trying to validate things.
So just move the unlocking to after the validate_mm() call.
Reported-by: kernel test robot <oliver.sang@intel.com>
Link: https://lore.kernel.org/lkml/ZKIsoMOT71uwCIZX@xsang-OptiPlex-9020/
Fixes: 408579cd627a ("mm: Update do_vmi_align_munmap() return semantics")
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Since do_vmi_align_munmap() will always honor the downgrade request on
the success, the callers no longer have to deal with confusing return
codes. Since all callers that request downgrade actually want the lock
to be dropped, change the downgrade to an unlock request.
Note that the lock still needs to be held in read mode during the page
table clean up to avoid races with a map request.
Update do_vmi_align_munmap() to return 0 for success. Clean up the
callers and comments to always expect the unlock to be honored on the
success path. The error path will always leave the lock untouched.
As part of the cleanup, the wrapper function do_vmi_munmap() and callers
to the wrapper are also updated.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/linux-mm/20230629191414.1215929-1-willy@infradead.org/
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Now that stack growth must always hold the mmap_lock for write, we can
always downgrade the mmap_lock to read and safely unmap pages from the
page table, even if we're next to a stack.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
MMU version of lock_mm_and_find_vma releases the mm lock before
returning when VMA is not found. Do the same in noMMU version.
This fixes hang on an attempt to handle protection fault.
Fixes: d85a143b69ab ("xtensa: fix NOMMU build with lock_mm_and_find_vma() conversion")
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
It turns out that xtensa has a really odd configuration situation: you
can do a no-MMU config, but still have the page fault code enabled.
Which doesn't sound all that sensible, but it turns out that xtensa can
have protection faults even without the MMU, and we have this:
config PFAULT
bool "Handle protection faults" if EXPERT && !MMU
default y
help
Handle protection faults. MMU configurations must enable it.
noMMU configurations may disable it if used memory map never
generates protection faults or faults are always fatal.
If unsure, say Y.
which completely violated my expectations of the page fault handling.
End result: Guenter reports that the xtensa no-MMU builds all fail with
arch/xtensa/mm/fault.c: In function ‘do_page_fault’:
arch/xtensa/mm/fault.c:133:8: error: implicit declaration of function ‘lock_mm_and_find_vma’
because I never exposed the new lock_mm_and_find_vma() function for the
no-MMU case.
Doing so is simple enough, and fixes the problem.
Reported-and-tested-by: Guenter Roeck <linux@roeck-us.net>
Fixes: a050ba1e7422 ("mm/fault: convert remaining simple cases to lock_mm_and_find_vma()")
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock
Pull memblock updates from Mike Rapoport:
- add test for memblock_alloc_node()
- minor coding style fixes
- add flags and nid info in memblock debugfs
* tag 'memblock-v6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock:
memblock: Update nid info in memblock debugfs
memblock: Add flags and nid info in memblock debugfs
Fix some coding style errors in memblock.c
Add tests for memblock_alloc_node()
|
|
Pull mm fix from David Woodhouse:
"Fix error return from do_vmi_align_munmap()"
* tag 'unmap-fix-20230629' of git://git.infradead.org/users/dwmw2/linux:
mm/mmap: Fix error return in do_vmi_align_munmap()
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab
Pull slab updates from Vlastimil Babka:
- SLAB deprecation:
Following the discussion at LSF/MM 2023 [1] and no objections, the
SLAB allocator is deprecated by renaming the config option (to make
its users notice) to CONFIG_SLAB_DEPRECATED with updated help text.
SLUB should be used instead. Existing defconfigs with CONFIG_SLAB are
also updated.
- SLAB_NO_MERGE kmem_cache flag (Jesper Dangaard Brouer):
There are (very limited) cases where kmem_cache merging is
undesirable, and existing ways to prevent it are hacky. Introduce a
new flag to do that cleanly and convert the existing hacky users.
Btrfs plans to use this for debug kernel builds (that use case is
always fine), networking for performance reasons (that should be very
rare).
- Replace the usage of weak PRNGs (David Keisar Schmidt):
In addition to using stronger RNGs for the security related features,
the code is a bit cleaner.
- Misc code cleanups (SeongJae Parki, Xiongwei Song, Zhen Lei, and
zhaoxinchao)
Link: https://lwn.net/Articles/932201/ [1]
* tag 'slab-for-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab:
mm/slab_common: use SLAB_NO_MERGE instead of negative refcount
mm/slab: break up RCU readers on SLAB_TYPESAFE_BY_RCU example code
mm/slab: add a missing semicolon on SLAB_TYPESAFE_BY_RCU example code
mm/slab_common: reduce an if statement in create_cache()
mm/slab: introduce kmem_cache flag SLAB_NO_MERGE
mm/slab: rename CONFIG_SLAB to CONFIG_SLAB_DEPRECATED
mm/slab: remove HAVE_HARDENED_USERCOPY_ALLOCATOR
mm/slab_common: Replace invocation of weak PRNG
mm/slab: Replace invocation of weak PRNG
slub: Don't read nr_slabs and total_objects directly
slub: Remove slabs_node() function
slub: Remove CONFIG_SMP defined check
slub: Put objects_show() into CONFIG_SLUB_DEBUG enabled block
slub: Correct the error code when slab_kset is NULL
mm/slab: correct return values in comment for _kmem_cache_create()
|
|
In commit a425ac5365f6 ("gup: add warning if some caller would seem to
want stack expansion") I added a temporary warning to catch any strange
GUP users that would be impacted by the fact that GUP no longer extends
the stack.
But it turns out that the warning is most easily triggered through
__access_remote_vm(), that already knows to expand the stack - it just
does it *after* calling GUP. So the warning is easy to trigger by just
running gdb (or similar) and accessing things remotely under the stack.
This just adds a temporary extra "expand stack early" to avoid the
warning for the already converted case - not because the warning is bad,
but because getting the warning for this known good case would then hide
any subsequent warnings for any actually interesting cases.
Let's try to remember to revert this change when we remove the warnings.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
There is no xas_pause(&xas) in collapse_file()'s main loop, at the points
where it does xas_unlock_irq(&xas) and then continues.
That would explain why, once two weeks ago and twice yesterday, I have
hit the VM_BUG_ON_PAGE(page != xas_load(&xas), page) since "mm/khugepaged:
fix iteration in collapse_file" removed the xas_set(&xas, index) just
before it: xas.xa_node could be left pointing to a stale node, if there
was concurrent activity on the file which transformed its xarray.
I tried inserting xas_pause()s, but then even bootup crashed on that
VM_BUG_ON_PAGE(): there appears to be a subtle "nextness" implicit in
xas_pause().
xas_next() and xas_pause() are good for use in simple loops, but not in
this one: xas_set() worked well until now, so use xas_set(&xas, index)
explicitly at the head of the loop; and change that VM_BUG_ON_PAGE() not
to need its own xas_set(), and not to interfere with the xa_state (which
would probably stop the crashes from xas_pause(), but I trust that less).
The user-visible effects of this bug (if VM_BUG_ONs are configured out)
would be data loss and data leak - potentially - though in practice I
expect it is more likely that a subsequent check (e.g. on mapping or on
nr_none) would notice an inconsistency, and just abandon the collapse.
Link: https://lore.kernel.org/linux-mm/f18e4b64-3f88-a8ab-56cc-d1f5f9c58d4@google.com/
Fixes: c8a8f3b4a95a ("mm/khugepaged: fix iteration in collapse_file")
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: stable@kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Stevens <stevensd@chromium.org>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
This modifies our user mode stack expansion code to always take the
mmap_lock for writing before modifying the VM layout.
It's actually something we always technically should have done, but
because we didn't strictly need it, we were being lazy ("opportunistic"
sounds so much better, doesn't it?) about things, and had this hack in
place where we would extend the stack vma in-place without doing the
proper locking.
And it worked fine. We just needed to change vm_start (or, in the case
of grow-up stacks, vm_end) and together with some special ad-hoc locking
using the anon_vma lock and the mm->page_table_lock, it all was fairly
straightforward.
That is, it was all fine until Ruihan Li pointed out that now that the
vma layout uses the maple tree code, we *really* don't just change
vm_start and vm_end any more, and the locking really is broken. Oops.
It's not actually all _that_ horrible to fix this once and for all, and
do proper locking, but it's a bit painful. We have basically three
different cases of stack expansion, and they all work just a bit
differently:
- the common and obvious case is the page fault handling. It's actually
fairly simple and straightforward, except for the fact that we have
something like 24 different versions of it, and you end up in a maze
of twisty little passages, all alike.
- the simplest case is the execve() code that creates a new stack.
There are no real locking concerns because it's all in a private new
VM that hasn't been exposed to anybody, but lockdep still can end up
unhappy if you get it wrong.
- and finally, we have GUP and page pinning, which shouldn't really be
expanding the stack in the first place, but in addition to execve()
we also use it for ptrace(). And debuggers do want to possibly access
memory under the stack pointer and thus need to be able to expand the
stack as a special case.
None of these cases are exactly complicated, but the page fault case in
particular is just repeated slightly differently many many times. And
ia64 in particular has a fairly complicated situation where you can have
both a regular grow-down stack _and_ a special grow-up stack for the
register backing store.
So to make this slightly more manageable, the bulk of this series is to
first create a helper function for the most common page fault case, and
convert all the straightforward architectures to it.
Thus the new 'lock_mm_and_find_vma()' helper function, which ends up
being used by x86, arm, powerpc, mips, riscv, alpha, arc, csky, hexagon,
loongarch, nios2, sh, sparc32, and xtensa. So we not only convert more
than half the architectures, we now have more shared code and avoid some
of those twisty little passages.
And largely due to this common helper function, the full diffstat of
this series ends up deleting more lines than it adds.
That still leaves eight architectures (ia64, m68k, microblaze, openrisc,
parisc, s390, sparc64 and um) that end up doing 'expand_stack()'
manually because they are doing something slightly different from the
normal pattern. Along with the couple of special cases in execve() and
GUP.
So there's a couple of patches that first create 'locked' helper
versions of the stack expansion functions, so that there's a obvious
path forward in the conversion. The execve() case is then actually
pretty simple, and is a nice cleanup from our old "grow-up stackls are
special, because at execve time even they grow down".
The #ifdef CONFIG_STACK_GROWSUP in that code just goes away, because
it's just more straightforward to write out the stack expansion there
manually, instead od having get_user_pages_remote() do it for us in some
situations but not others and have to worry about locking rules for GUP.
And the final step is then to just convert the remaining odd cases to a
new world order where 'expand_stack()' is called with the mmap_lock held
for reading, but where it might drop it and upgrade it to a write, only
to return with it held for reading (in the success case) or with it
completely dropped (in the failure case).
In the process, we remove all the stack expansion from GUP (where
dropping the lock wouldn't be ok without special rules anyway), and add
it in manually to __access_remote_vm() for ptrace().
Thanks to Adrian Glaubitz and Frank Scheiner who tested the ia64 cases.
Everything else here felt pretty straightforward, but the ia64 rules for
stack expansion are really quite odd and very different from everything
else. Also thanks to Vegard Nossum who caught me getting one of those
odd conditions entirely the wrong way around.
Anyway, I think I want to actually move all the stack expansion code to
a whole new file of its own, rather than have it split up between
mm/mmap.c and mm/memory.c, but since this will have to be backported to
the initial maple tree vma introduction anyway, I tried to keep the
patches _fairly_ minimal.
Also, while I don't think it's valid to expand the stack from GUP, the
final patch in here is a "warn if some crazy GUP user wants to try to
expand the stack" patch. That one will be reverted before the final
release, but it's left to catch any odd cases during the merge window
and release candidates.
Reported-by: Ruihan Li <lrh2000@pku.edu.cn>
* branch 'expand-stack':
gup: add warning if some caller would seem to want stack expansion
mm: always expand the stack with the mmap write lock held
execve: expand new process stack manually ahead of time
mm: make find_extend_vma() fail if write lock not held
powerpc/mm: convert coprocessor fault to lock_mm_and_find_vma()
mm/fault: convert remaining simple cases to lock_mm_and_find_vma()
arm/mm: Convert to using lock_mm_and_find_vma()
riscv/mm: Convert to using lock_mm_and_find_vma()
mips/mm: Convert to using lock_mm_and_find_vma()
powerpc/mm: Convert to using lock_mm_and_find_vma()
arm64/mm: Convert to using lock_mm_and_find_vma()
mm: make the page fault mmap locking killable
mm: introduce new 'lock_mm_and_find_vma()' page fault helper
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking changes from Jakub Kicinski:
"WiFi 7 and sendpage changes are the biggest pieces of work for this
release. The latter will definitely require fixes but I think that we
got it to a reasonable point.
Core:
- Rework the sendpage & splice implementations
Instead of feeding data into sockets page by page extend sendmsg
handlers to support taking a reference on the data, controlled by a
new flag called MSG_SPLICE_PAGES
Rework the handling of unexpected-end-of-file to invoke an
additional callback instead of trying to predict what the right
combination of MORE/NOTLAST flags is
Remove the MSG_SENDPAGE_NOTLAST flag completely
- Implement SCM_PIDFD, a new type of CMSG type analogous to
SCM_CREDENTIALS, but it contains pidfd instead of plain pid
- Enable socket busy polling with CONFIG_RT
- Improve reliability and efficiency of reporting for ref_tracker
- Auto-generate a user space C library for various Netlink families
Protocols:
- Allow TCP to shrink the advertised window when necessary, prevent
sk_rcvbuf auto-tuning from growing the window all the way up to
tcp_rmem[2]
- Use per-VMA locking for "page-flipping" TCP receive zerocopy
- Prepare TCP for device-to-device data transfers, by making sure
that payloads are always attached to skbs as page frags
- Make the backoff time for the first N TCP SYN retransmissions
linear. Exponential backoff is unnecessarily conservative
- Create a new MPTCP getsockopt to retrieve all info
(MPTCP_FULL_INFO)
- Avoid waking up applications using TLS sockets until we have a full
record
- Allow using kernel memory for protocol ioctl callbacks, paving the
way to issuing ioctls over io_uring
- Add nolocalbypass option to VxLAN, forcing packets to be fully
encapsulated even if they are destined for a local IP address
- Make TCPv4 use consistent hash in TIME_WAIT and SYN_RECV. Ensure
in-kernel ECMP implementation (e.g. Open vSwitch) select the same
link for all packets. Support L4 symmetric hashing in Open vSwitch
- PPPoE: make number of hash bits configurable
- Allow DNS to be overwritten by DHCPACK in the in-kernel DHCP client
(ipconfig)
- Add layer 2 miss indication and filtering, allowing higher layers
(e.g. ACL filters) to make forwarding decisions based on whether
packet matched forwarding state in lower devices (bridge)
- Support matching on Connectivity Fault Management (CFM) packets
- Hide the "link becomes ready" IPv6 messages by demoting their
printk level to debug
- HSR: don't enable promiscuous mode if device offloads the proto
- Support active scanning in IEEE 802.15.4
- Continue work on Multi-Link Operation for WiFi 7
BPF:
- Add precision propagation for subprogs and callbacks. This allows
maintaining verification efficiency when subprograms are used, or
in fact passing the verifier at all for complex programs,
especially those using open-coded iterators
- Improve BPF's {g,s}setsockopt() length handling. Previously BPF
assumed the length is always equal to the amount of written data.
But some protos allow passing a NULL buffer to discover what the
output buffer *should* be, without writing anything
- Accept dynptr memory as memory arguments passed to helpers
- Add routing table ID to bpf_fib_lookup BPF helper
- Support O_PATH FDs in BPF_OBJ_PIN and BPF_OBJ_GET commands
- Drop bpf_capable() check in BPF_MAP_FREEZE command (used to mark
maps as read-only)
- Show target_{obj,btf}_id in tracing link fdinfo
- Addition of several new kfuncs (most of the names are
self-explanatory):
- Add a set of new dynptr kfuncs: bpf_dynptr_adjust(),
bpf_dynptr_is_null(), bpf_dynptr_is_rdonly(), bpf_dynptr_size()
and bpf_dynptr_clone().
- bpf_task_under_cgroup()
- bpf_sock_destroy() - force closing sockets
- bpf_cpumask_first_and(), rework bpf_cpumask_any*() kfuncs
Netfilter:
- Relax set/map validation checks in nf_tables. Allow checking
presence of an entry in a map without using the value
- Increase ip_vs_conn_tab_bits range for 64BIT builds
- Allow updating size of a set
- Improve NAT tuple selection when connection is closing
Driver API:
- Integrate netdev with LED subsystem, to allow configuring HW
"offloaded" blinking of LEDs based on link state and activity
(i.e. packets coming in and out)
- Support configuring rate selection pins of SFP modules
- Factor Clause 73 auto-negotiation code out of the drivers, provide
common helper routines
- Add more fool-proof helpers for managing lifetime of MDIO devices
associated with the PCS layer
- Allow drivers to report advanced statistics related to Time Aware
scheduler offload (taprio)
- Allow opting out of VF statistics in link dump, to allow more VFs
to fit into the message
- Split devlink instance and devlink port operations
New hardware / drivers:
- Ethernet:
- Synopsys EMAC4 IP support (stmmac)
- Marvell 88E6361 8 port (5x1GE + 3x2.5GE) switches
- Marvell 88E6250 7 port switches
- Microchip LAN8650/1 Rev.B0 PHYs
- MediaTek MT7981/MT7988 built-in 1GE PHY driver
- WiFi:
- Realtek RTL8192FU, 2.4 GHz, b/g/n mode, 2T2R, 300 Mbps
- Realtek RTL8723DS (SDIO variant)
- Realtek RTL8851BE
- CAN:
- Fintek F81604
Drivers:
- Ethernet NICs:
- Intel (100G, ice):
- support dynamic interrupt allocation
- use meta data match instead of VF MAC addr on slow-path
- nVidia/Mellanox:
- extend link aggregation to handle 4, rather than just 2 ports
- spawn sub-functions without any features by default
- OcteonTX2:
- support HTB (Tx scheduling/QoS) offload
- make RSS hash generation configurable
- support selecting Rx queue using TC filters
- Wangxun (ngbe/txgbe):
- add basic Tx/Rx packet offloads
- add phylink support (SFP/PCS control)
- Freescale/NXP (enetc):
- report TAPRIO packet statistics
- Solarflare/AMD:
- support matching on IP ToS and UDP source port of outer
header
- VxLAN and GENEVE tunnel encapsulation over IPv4 or IPv6
- add devlink dev info support for EF10
- Virtual NICs:
- Microsoft vNIC:
- size the Rx indirection table based on requested
configuration
- support VLAN tagging
- Amazon vNIC:
- try to reuse Rx buffers if not fully consumed, useful for ARM
servers running with 16kB pages
- Google vNIC:
- support TCP segmentation of >64kB frames
- Ethernet embedded switches:
- Marvell (mv88e6xxx):
- enable USXGMII (88E6191X)
- Microchip:
- lan966x: add support for Egress Stage 0 ACL engine
- lan966x: support mapping packet priority to internal switch
priority (based on PCP or DSCP)
- Ethernet PHYs:
- Broadcom PHYs:
- support for Wake-on-LAN for BCM54210E/B50212E
- report LPI counter
- Microsemi PHYs: support RGMII delay configuration (VSC85xx)
- Micrel PHYs: receive timestamp in the frame (LAN8841)
- Realtek PHYs: support optional external PHY clock
- Altera TSE PCS: merge the driver into Lynx PCS which it is a
variant of
- CAN: Kvaser PCIEcan:
- support packet timestamping
- WiFi:
- Intel (iwlwifi):
- major update for new firmware and Multi-Link Operation (MLO)
- configuration rework to drop test devices and split the
different families
- support for segmented PNVM images and power tables
- new vendor entries for PPAG (platform antenna gain) feature
- Qualcomm 802.11ax (ath11k):
- Multiple Basic Service Set Identifier (MBSSID) and Enhanced
MBSSID Advertisement (EMA) support in AP mode
- support factory test mode
- RealTek (rtw89):
- add RSSI based antenna diversity
- support U-NII-4 channels on 5 GHz band
- RealTek (rtl8xxxu):
- AP mode support for 8188f
- support USB RX aggregation for the newer chips"
* tag 'net-next-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1602 commits)
net: scm: introduce and use scm_recv_unix helper
af_unix: Skip SCM_PIDFD if scm->pid is NULL.
net: lan743x: Simplify comparison
netlink: Add __sock_i_ino() for __netlink_diag_dump().
net: dsa: avoid suspicious RCU usage for synced VLAN-aware MAC addresses
Revert "af_unix: Call scm_recv() only after scm_set_cred()."
phylink: ReST-ify the phylink_pcs_neg_mode() kdoc
libceph: Partially revert changes to support MSG_SPLICE_PAGES
net: phy: mscc: fix packet loss due to RGMII delays
net: mana: use vmalloc_array and vcalloc
net: enetc: use vmalloc_array and vcalloc
ionic: use vmalloc_array and vcalloc
pds_core: use vmalloc_array and vcalloc
gve: use vmalloc_array and vcalloc
octeon_ep: use vmalloc_array and vcalloc
net: usb: qmi_wwan: add u-blox 0x1312 composition
perf trace: fix MSG_SPLICE_PAGES build error
ipvlan: Fix return value of ipvlan_queue_xmit()
netfilter: nf_tables: fix underflow in chain reference counter
netfilter: nf_tables: unbind non-anonymous set if rule construction fails
...
|
|
Commit ca5e863233e8 ("mm/gup: remove vmas parameter from
get_user_pages_remote()") removed the vma argument from GUP handling,
and instead added a helper function (get_user_page_vma_remote()) that
looks it up separately using 'vma_lookup()'. And then converted
existing users that needed a vma to use the helper instead.
However, the helper function intentionally acts exactly like the old
get_user_pages_remote() did, and only fills in 'vma' on successful page
lookup. Fine so far.
However, __access_remote_vm() wants the vma even for the unsuccessful
case, and used to do a
vma = vma_lookup(mm, addr);
explicitly to look it up when the get_user_page() failed.
However, that conversion commit incorrectly removed that vma lookup,
thinking that get_user_page_vma_remote() would have done it. Not so.
So add the vma_lookup() back in.
Fixes: ca5e863233e8 ("mm/gup: remove vmas parameter from get_user_pages_remote()")
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-mm updates from Andrew Morton:
- Arnd Bergmann has fixed a bunch of -Wmissing-prototypes in top-level
directories
- Douglas Anderson has added a new "buddy" mode to the hardlockup
detector. It permits the detector to work on architectures which
cannot provide the required interrupts, by having CPUs periodically
perform checks on other CPUs
- Zhen Lei has enhanced kexec's ability to support two crash regions
- Petr Mladek has done a lot of cleanup on the hard lockup detector's
Kconfig entries
- And the usual bunch of singleton patches in various places
* tag 'mm-nonmm-stable-2023-06-24-19-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (72 commits)
kernel/time/posix-stubs.c: remove duplicated include
ocfs2: remove redundant assignment to variable bit_off
watchdog/hardlockup: fix typo in config HARDLOCKUP_DETECTOR_PREFER_BUDDY
powerpc: move arch_trigger_cpumask_backtrace from nmi.h to irq.h
devres: show which resource was invalid in __devm_ioremap_resource()
watchdog/hardlockup: define HARDLOCKUP_DETECTOR_ARCH
watchdog/sparc64: define HARDLOCKUP_DETECTOR_SPARC64
watchdog/hardlockup: make HAVE_NMI_WATCHDOG sparc64-specific
watchdog/hardlockup: declare arch_touch_nmi_watchdog() only in linux/nmi.h
watchdog/hardlockup: make the config checks more straightforward
watchdog/hardlockup: sort hardlockup detector related config values a logical way
watchdog/hardlockup: move SMP barriers from common code to buddy code
watchdog/buddy: simplify the dependency for HARDLOCKUP_DETECTOR_PREFER_BUDDY
watchdog/buddy: don't copy the cpumask in watchdog_next_cpu()
watchdog/buddy: cleanup how watchdog_buddy_check_hardlockup() is called
watchdog/hardlockup: remove softlockup comment in touch_nmi_watchdog()
watchdog/hardlockup: in watchdog_hardlockup_check() use cpumask_copy()
watchdog/hardlockup: don't use raw_cpu_ptr() in watchdog_hardlockup_kick()
watchdog/hardlockup: HAVE_NMI_WATCHDOG must implement watchdog_hardlockup_probe()
watchdog/hardlockup: keep kernel.nmi_watchdog sysctl as 0444 if probe fails
...
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull mm updates from Andrew Morton:
- Yosry Ahmed brought back some cgroup v1 stats in OOM logs
- Yosry has also eliminated cgroup's atomic rstat flushing
- Nhat Pham adds the new cachestat() syscall. It provides userspace
with the ability to query pagecache status - a similar concept to
mincore() but more powerful and with improved usability
- Mel Gorman provides more optimizations for compaction, reducing the
prevalence of page rescanning
- Lorenzo Stoakes has done some maintanance work on the
get_user_pages() interface
- Liam Howlett continues with cleanups and maintenance work to the
maple tree code. Peng Zhang also does some work on maple tree
- Johannes Weiner has done some cleanup work on the compaction code
- David Hildenbrand has contributed additional selftests for
get_user_pages()
- Thomas Gleixner has contributed some maintenance and optimization
work for the vmalloc code
- Baolin Wang has provided some compaction cleanups,
- SeongJae Park continues maintenance work on the DAMON code
- Huang Ying has done some maintenance on the swap code's usage of
device refcounting
- Christoph Hellwig has some cleanups for the filemap/directio code
- Ryan Roberts provides two patch series which yield some
rationalization of the kernel's access to pte entries - use the
provided APIs rather than open-coding accesses
- Lorenzo Stoakes has some fixes to the interaction between pagecache
and directio access to file mappings
- John Hubbard has a series of fixes to the MM selftesting code
- ZhangPeng continues the folio conversion campaign
- Hugh Dickins has been working on the pagetable handling code, mainly
with a view to reducing the load on the mmap_lock
- Catalin Marinas has reduced the arm64 kmalloc() minimum alignment
from 128 to 8
- Domenico Cerasuolo has improved the zswap reclaim mechanism by
reorganizing the LRU management
- Matthew Wilcox provides some fixups to make gfs2 work better with the
buffer_head code
- Vishal Moola also has done some folio conversion work
- Matthew Wilcox has removed the remnants of the pagevec code - their
functionality is migrated over to struct folio_batch
* tag 'mm-stable-2023-06-24-19-15' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (380 commits)
mm/hugetlb: remove hugetlb_set_page_subpool()
mm: nommu: correct the range of mmap_sem_read_lock in task_mem()
hugetlb: revert use of page_cache_next_miss()
Revert "page cache: fix page_cache_next/prev_miss off by one"
mm/vmscan: fix root proactive reclaim unthrottling unbalanced node
mm: memcg: rename and document global_reclaim()
mm: kill [add|del]_page_to_lru_list()
mm: compaction: convert to use a folio in isolate_migratepages_block()
mm: zswap: fix double invalidate with exclusive loads
mm: remove unnecessary pagevec includes
mm: remove references to pagevec
mm: rename invalidate_mapping_pagevec to mapping_try_invalidate
mm: remove struct pagevec
net: convert sunrpc from pagevec to folio_batch
i915: convert i915_gpu_error to use a folio_batch
pagevec: rename fbatch_count()
mm: remove check_move_unevictable_pages()
drm: convert drm_gem_put_pages() to use a folio_batch
i915: convert shmem_sg_free_table() to use a folio_batch
scatterlist: add sg_set_folio()
...
|
|
If mas_store_gfp() in the gather loop failed, the 'error' variable that
ultimately gets returned was not being set. In many cases, its original
value of -ENOMEM was still in place, and that was fine. But if VMAs had
been split at the start or end of the range, then 'error' could be zero.
Change to the 'error = foo(); if (error) goto …' idiom to fix the bug.
Also clean up a later case which avoided the same bug by *explicitly*
setting error = -ENOMEM right before calling the function that might
return -ENOMEM.
In a final cosmetic change, move the 'Point of no return' comment to
*after* the goto. That's been in the wrong place since the preallocation
was removed, and this new error path was added.
Fixes: 606c812eb1d5 ("mm/mmap: Fix error path in do_vmi_align_munmap()")
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Cc: stable@vger.kernel.org
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
|
|
Pull arm64 documentation move from Jonathan Corbet:
"Move the arm64 architecture documentation under Documentation/arch/.
This brings some order to the documentation directory, declutters the
top-level directory, and makes the documentation organization more
closely match that of the source"
* tag 'docs-arm64-move' of git://git.lwn.net/linux:
perf arm-spe: Fix a dangling Documentation/arm64 reference
mm: Fix a dangling Documentation/arm64 reference
arm64: Fix dangling references to Documentation/arm64
dt-bindings: fix dangling Documentation/arm64 reference
docs: arm64: Move arm64 documentation under Documentation/arch/
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar:
- Introduce cmpxchg128() -- aka. the demise of cmpxchg_double()
The cmpxchg128() family of functions is basically & functionally the
same as cmpxchg_double(), but with a saner interface.
Instead of a 6-parameter horror that forced u128 - u64/u64-halves
layout details on the interface and exposed users to complexity,
fragility & bugs, use a natural 3-parameter interface with u128
types.
- Restructure the generated atomic headers, and add kerneldoc comments
for all of the generic atomic{,64,_long}_t operations.
The generated definitions are much cleaner now, and come with
documentation.
- Implement lock_set_cmp_fn() on lockdep, for defining an ordering when
taking multiple locks of the same type.
This gets rid of one use of lockdep_set_novalidate_class() in the
bcache code.
- Fix raw_cpu_generic_try_cmpxchg() bug due to an unintended variable
shadowing generating garbage code on Clang on certain ARM builds.
* tag 'locking-core-2023-06-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (43 commits)
locking/atomic: scripts: fix ${atomic}_dec_if_positive() kerneldoc
percpu: Fix self-assignment of __old in raw_cpu_generic_try_cmpxchg()
locking/atomic: treewide: delete arch_atomic_*() kerneldoc
locking/atomic: docs: Add atomic operations to the driver basic API documentation
locking/atomic: scripts: generate kerneldoc comments
docs: scripts: kernel-doc: accept bitwise negation like ~@var
locking/atomic: scripts: simplify raw_atomic*() definitions
locking/atomic: scripts: simplify raw_atomic_long*() definitions
locking/atomic: scripts: split pfx/name/sfx/order
locking/atomic: scripts: restructure fallback ifdeffery
locking/atomic: scripts: build raw_atomic_long*() directly
locking/atomic: treewide: use raw_atomic*_<op>()
locking/atomic: scripts: add trivial raw_atomic*_<op>()
locking/atomic: scripts: factor out order template generation
locking/atomic: scripts: remove leftover "${mult}"
locking/atomic: scripts: remove bogus order parameter
locking/atomic: xtensa: add preprocessor symbols
locking/atomic: x86: add preprocessor symbols
locking/atomic: sparc: add preprocessor symbols
locking/atomic: sh: add preprocessor symbols
...
|
|
It feels very unlikely that anybody would want to do a GUP in an
unmapped area under the stack pointer, but real users sometimes do some
really strange things. So add a (temporary) warning for the case where
a GUP fails and expanding the stack might have made it work.
It's trivial to do the expansion in the caller as part of getting the mm
lock in the first place - see __access_remote_vm() for ptrace, for
example - it's just that it's unnecessarily painful to do it deep in the
guts of the GUP lookup when we might have to drop and re-take the lock.
I doubt anybody actually does anything quite this strange, but let's be
proactive: adding these warnings is simple, and will make debugging it
much easier if they trigger.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
This finishes the job of always holding the mmap write lock when
extending the user stack vma, and removes the 'write_locked' argument
from the vm helper functions again.
For some cases, we just avoid expanding the stack at all: drivers and
page pinning really shouldn't be extending any stacks. Let's see if any
strange users really wanted that.
It's worth noting that architectures that weren't converted to the new
lock_mm_and_find_vma() helper function are left using the legacy
"expand_stack()" function, but it has been changed to drop the mmap_lock
and take it for writing while expanding the vma. This makes it fairly
straightforward to convert the remaining architectures.
As a result of dropping and re-taking the lock, the calling conventions
for this function have also changed, since the old vma may no longer be
valid. So it will now return the new vma if successful, and NULL - and
the lock dropped - if the area could not be extended.
Tested-by: Vegard Nossum <vegard.nossum@oracle.com>
Tested-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> # ia64
Tested-by: Frank Scheiner <frank.scheiner@web.de> # ia64
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cleanups from Dave Hansen:
"As usual, these are all over the map. The biggest cluster is work from
Arnd to eliminate -Wmissing-prototype warnings:
- Address -Wmissing-prototype warnings
- Remove repeated 'the' in comments
- Remove unused current_untag_mask()
- Document urgent tip branch timing
- Clean up MSR kernel-doc notation
- Clean up paravirt_ops doc
- Update Srivatsa S. Bhat's maintained areas
- Remove unused extern declaration acpi_copy_wakeup_routine()"
* tag 'x86_cleanups_for_6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (22 commits)
x86/acpi: Remove unused extern declaration acpi_copy_wakeup_routine()
Documentation: virt: Clean up paravirt_ops doc
x86/mm: Remove unused current_untag_mask()
x86/mm: Remove repeated word in comments
x86/lib/msr: Clean up kernel-doc notation
x86/platform: Avoid missing-prototype warnings for OLPC
x86/mm: Add early_memremap_pgprot_adjust() prototype
x86/usercopy: Include arch_wb_cache_pmem() declaration
x86/vdso: Include vdso/processor.h
x86/mce: Add copy_mc_fragile_handle_tail() prototype
x86/fbdev: Include asm/fb.h as needed
x86/hibernate: Declare global functions in suspend.h
x86/entry: Add do_SYSENTER_32() prototype
x86/quirks: Include linux/pnp.h for arch_pnpbios_disabled()
x86/mm: Include asm/numa.h for set_highmem_pages_init()
x86: Avoid missing-prototype warnings for doublefault code
x86/fpu: Include asm/fpu/regset.h
x86: Add dummy prototype for mk_early_pgtbl_32()
x86/pci: Mark local functions as 'static'
x86/ftrace: Move prepare_ftrace_return prototype to header
...
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 confidential computing update from Borislav Petkov:
- Add support for unaccepted memory as specified in the UEFI spec v2.9.
The gist of it all is that Intel TDX and AMD SEV-SNP confidential
computing guests define the notion of accepting memory before using
it and thus preventing a whole set of attacks against such guests
like memory replay and the like.
There are a couple of strategies of how memory should be accepted -
the current implementation does an on-demand way of accepting.
* tag 'x86_cc_for_v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
virt: sevguest: Add CONFIG_CRYPTO dependency
x86/efi: Safely enable unaccepted memory in UEFI
x86/sev: Add SNP-specific unaccepted memory support
x86/sev: Use large PSC requests if applicable
x86/sev: Allow for use of the early boot GHCB for PSC requests
x86/sev: Put PSC struct on the stack in prep for unaccepted memory support
x86/sev: Fix calculation of end address based on number of pages
x86/tdx: Add unaccepted memory support
x86/tdx: Refactor try_accept_one()
x86/tdx: Make _tdx_hypercall() and __tdx_module_call() available in boot stub
efi/unaccepted: Avoid load_unaligned_zeropad() stepping into unaccepted memory
efi: Add unaccepted memory support
x86/boot/compressed: Handle unaccepted memory
efi/libstub: Implement support for unaccepted memory
efi/x86: Get full memory map in allocate_e820()
mm: Add support for unaccepted memory
|
|
Pull block updates from Jens Axboe:
- NVMe pull request via Keith:
- Various cleanups all around (Irvin, Chaitanya, Christophe)
- Better struct packing (Christophe JAILLET)
- Reduce controller error logs for optional commands (Keith)
- Support for >=64KiB block sizes (Daniel Gomez)
- Fabrics fixes and code organization (Max, Chaitanya, Daniel
Wagner)
- bcache updates via Coly:
- Fix a race at init time (Mingzhe Zou)
- Misc fixes and cleanups (Andrea, Thomas, Zheng, Ye)
- use page pinning in the block layer for dio (David)
- convert old block dio code to page pinning (David, Christoph)
- cleanups for pktcdvd (Andy)
- cleanups for rnbd (Guoqing)
- use the unchecked __bio_add_page() for the initial single page
additions (Johannes)
- fix overflows in the Amiga partition handling code (Michael)
- improve mq-deadline zoned device support (Bart)
- keep passthrough requests out of the IO schedulers (Christoph, Ming)
- improve support for flush requests, making them less special to deal
with (Christoph)
- add bdev holder ops and shutdown methods (Christoph)
- fix the name_to_dev_t() situation and use cases (Christoph)
- decouple the block open flags from fmode_t (Christoph)
- ublk updates and cleanups, including adding user copy support (Ming)
- BFQ sanity checking (Bart)
- convert brd from radix to xarray (Pankaj)
- constify various structures (Thomas, Ivan)
- more fine grained persistent reservation ioctl capability checks
(Jingbo)
- misc fixes and cleanups (Arnd, Azeem, Demi, Ed, Hengqi, Hou, Jan,
Jordy, Li, Min, Yu, Zhong, Waiman)
* tag 'for-6.5/block-2023-06-23' of git://git.kernel.dk/linux: (266 commits)
scsi/sg: don't grab scsi host module reference
ext4: Fix warning in blkdev_put()
block: don't return -EINVAL for not found names in devt_from_devname
cdrom: Fix spectre-v1 gadget
block: Improve kernel-doc headers
blk-mq: don't insert passthrough request into sw queue
bsg: make bsg_class a static const structure
ublk: make ublk_chr_class a static const structure
aoe: make aoe_class a static const structure
block/rnbd: make all 'class' structures const
block: fix the exclusive open mask in disk_scan_partitions
block: add overflow checks for Amiga partition support
block: change all __u32 annotations to __be32 in affs_hardblocks.h
block: fix signed int overflow in Amiga partition support
block: add capacity validation in bdev_add_partition()
block: fine-granular CAP_SYS_ADMIN for Persistent Reservation
block: disallow Persistent Reservation on partitions
reiserfs: fix blkdev_put() warning from release_journal_dev()
block: fix wrong mode for blkdev_get_by_dev() from disk_scan_partitions()
block: document the holder argument to blkdev_get_by_path
...
|
|
Pull splice updates from Jens Axboe:
"This kills off ITER_PIPE to avoid a race between truncate,
iov_iter_revert() on the pipe and an as-yet incomplete DMA to a bio
with unpinned/unref'ed pages from an O_DIRECT splice read. This causes
memory corruption.
Instead, we either use (a) filemap_splice_read(), which invokes the
buffered file reading code and splices from the pagecache into the
pipe; (b) copy_splice_read(), which bulk-allocates a buffer, reads
into it and then pushes the filled pages into the pipe; or (c) handle
it in filesystem-specific code.
Summary:
- Rename direct_splice_read() to copy_splice_read()
- Simplify the calculations for the number of pages to be reclaimed
in copy_splice_read()
- Turn do_splice_to() into a helper, vfs_splice_read(), so that it
can be used by overlayfs and coda to perform the checks on the
lower fs
- Make vfs_splice_read() jump to copy_splice_read() to handle
direct-I/O and DAX
- Provide shmem with its own splice_read to handle non-existent pages
in the pagecache. We don't want a ->read_folio() as we don't want
to populate holes, but filemap_get_pages() requires it
- Provide overlayfs with its own splice_read to call down to a lower
layer as overlayfs doesn't provide ->read_folio()
- Provide coda with its own splice_read to call down to a lower layer
as coda doesn't provide ->read_folio()
- Direct ->splice_read to copy_splice_read() in tty, procfs, kernfs
and random files as they just copy to the output buffer and don't
splice pages
- Provide wrappers for afs, ceph, ecryptfs, ext4, f2fs, nfs, ntfs3,
ocfs2, orangefs, xfs and zonefs to do locking and/or revalidation
- Make cifs use filemap_splice_read()
- Replace pointers to generic_file_splice_read() with pointers to
filemap_splice_read() as DIO and DAX are handled in the caller;
filesystems can still provide their own alternate ->splice_read()
op
- Remove generic_file_splice_read()
- Remove ITER_PIPE and its paraphernalia as generic_file_splice_read
was the only user"
* tag 'for-6.5/splice-2023-06-23' of git://git.kernel.dk/linux: (31 commits)
splice: kdoc for filemap_splice_read() and copy_splice_read()
iov_iter: Kill ITER_PIPE
splice: Remove generic_file_splice_read()
splice: Use filemap_splice_read() instead of generic_file_splice_read()
cifs: Use filemap_splice_read()
trace: Convert trace/seq to use copy_splice_read()
zonefs: Provide a splice-read wrapper
xfs: Provide a splice-read wrapper
orangefs: Provide a splice-read wrapper
ocfs2: Provide a splice-read wrapper
ntfs3: Provide a splice-read wrapper
nfs: Provide a splice-read wrapper
f2fs: Provide a splice-read wrapper
ext4: Provide a splice-read wrapper
ecryptfs: Provide a splice-read wrapper
ceph: Provide a splice-read wrapper
afs: Provide a splice-read wrapper
9p: Add splice_read wrapper
net: Make sock_splice_read() use copy_splice_read() by default
tty, proc, kernfs, random: Use copy_splice_read()
...
|
|
Make calls to extend_vma() and find_extend_vma() fail if the write lock
is required.
To avoid making this a flag-day event, this still allows the old
read-locking case for the trivial situations, and passes in a flag to
say "is it write-locked". That way write-lockers can say "yes, I'm
being careful", and legacy users will continue to work in all the common
cases until they have been fully converted to the new world order.
Co-Developed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
arm has an additional check for address < FIRST_USER_ADDRESS before
expanding the stack. Since FIRST_USER_ADDRESS is defined everywhere
(generally as 0), move that check to the generic expand_downwards().
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
This is done as a separate patch from introducing the new
lock_mm_and_find_vma() helper, because while it's an obvious change,
it's not what x86 used to do in this area.
We already abort the page fault on fatal signals anyway, so why should
we wait for the mmap lock only to then abort later? With the new helper
function that returns without the lock held on failure anyway, this is
particularly easy and straightforward.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
.. and make x86 use it.
This basically extracts the existing x86 "find and expand faulting vma"
code, but extends it to also take the mmap lock for writing in case we
actually do need to expand the vma.
We've historically short-circuited that case, and have some rather ugly
special logic to serialize the stack segment expansion (since we only
hold the mmap lock for reading) that doesn't match the normal VM
locking.
That slight violation of locking worked well, right up until it didn't:
the maple tree code really does want proper locking even for simple
extension of an existing vma.
So extract the code for "look up the vma of the fault" from x86, fix it
up to do the necessary write locking, and make it available as a helper
function for other architectures that can use the common helper.
Note: I say "common helper", but it really only handles the normal
stack-grows-down case. Which is all architectures except for PA-RISC
and IA64. So some rare architectures can't use the helper, but if they
care they'll just need to open-code this logic.
It's also worth pointing out that this code really would like to have an
optimistic "mmap_upgrade_trylock()" to make it quicker to go from a
read-lock (for the common case) to taking the write lock (for having to
extend the vma) in the normal single-threaded situation where there is
no other locking activity.
But that _is_ all the very uncommon special case, so while it would be
nice to have such an operation, it probably doesn't matter in reality.
I did put in the skeleton code for such a possible future expansion,
even if it only acts as pseudo-documentation for what we're doing.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Ackerley Tng reported an issue with hugetlbfs fallocate as noted in the
Closes tag. The issue showed up after the conversion of hugetlb page
cache lookup code to use page_cache_next_miss. User visible effects are:
- hugetlbfs fallocate incorrectly returns -EEXIST if pages are presnet
in the file.
- hugetlb pages will not be included in core dumps if they need to be
brought in via GUP.
- userfaultfd UFFDIO_COPY will not notice pages already present in the
cache. It may try to allocate a new page and potentially return
ENOMEM as opposed to EEXIST.
Revert the use page_cache_next_miss() in hugetlb code.
IMPORTANT NOTE FOR STABLE BACKPORTS:
This patch will apply cleanly to v6.3. However, due to the change of
filemap_get_folio() return values, it will not function correctly. This
patch must be modified for stable backports.
[dan.carpenter@linaro.org: fix hugetlbfs_pagecache_present()]
Link: https://lkml.kernel.org/r/efa86091-6a2c-4064-8f55-9b44e1313015@moroto.mountain
Link: https://lkml.kernel.org/r/20230621212403.174710-2-mike.kravetz@oracle.com
Fixes: d0ce0e47b323 ("mm/hugetlb: convert hugetlb fault paths to use alloc_hugetlb_folio()")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reported-by: Ackerley Tng <ackerleytng@google.com>
Closes: https://lore.kernel.org/linux-mm/cover.1683069252.git.ackerleytng@google.com
Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Vishal Annapurve <vannapurve@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
This reverts commit 9425c591e06a9ab27a145ba655fb50532cf0bcc9
The reverted commit fixed up routines primarily used by readahead code
such that they could also be used by hugetlb. Unfortunately, this
caused a performance regression as pointed out by the Closes: tag.
The hugetlb code which uses page_cache_next_miss will be addressed in
a subsequent patch.
Link: https://lkml.kernel.org/r/20230621212403.174710-1-mike.kravetz@oracle.com
Fixes: 9425c591e06a ("page cache: fix page_cache_next/prev_miss off by one")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202306211346.1e9ff03e-oliver.sang@intel.com
Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Ackerley Tng <ackerleytng@google.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Vishal Annapurve <vannapurve@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
When memory.reclaim was introduced, it became the first case where
cgroup_reclaim() is true for the root cgroup. Johannes concluded [1] that
for most cases this is okay, except for one case. Historically, kswapd
would throttle reclaim on a node if a lot of pages marked for reclaim are
under writeback (aka the node is congested). This occurred by setting
LRUVEC_CONGESTED bit in lruvec->flags. The bit would be cleared when the
node is balanced.
Similarly, cgroup reclaim would set the same bit when an lruvec is
congested, and clear it on the way out of reclaim (to throttle local
reclaimers).
Before the introduction of memory.reclaim, the root memcg was the only
target of kswapd reclaim, and non-root memcgs were the only targets of
cgroup reclaim, so they would never interfere. Using the same bit for
both was fine. After memory.reclaim, it is possible for cgroup reclaim on
the root cgroup to clear the bit set by kswapd. This would result in
reclaim on the node to be unthrottled before the node is balanced.
Fix this by introducing separate bits for cgroup-level and node-level
congestion. kswapd can unthrottle an lruvec that is marked as congested
by cgroup reclaim (as the entire node should no longer be congested), but
not vice versa (to prevent premature unthrottling before the entire node
is balanced).
[1]https://lore.kernel.org/lkml/20230405200150.GA35884@cmpxchg.org/
Link: https://lkml.kernel.org/r/20230621023101.432780-1-yosryahmed@google.com
Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Reported-by: Johannes Weiner <hannes@cmpxchg.org>
Closes: https://lore.kernel.org/lkml/20230405200150.GA35884@cmpxchg.org/
Cc: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Evidently, global_reclaim() can be a confusing name. Especially that it
used to exist before with a subtly different definition (removed by commit
b5ead35e7e1d ("mm: vmscan: naming fixes: global_reclaim() and
sane_reclaim()"). It can be interpreted as non-cgroup reclaim, even
though it returns true for cgroup reclaim on the root memcg (through
memory.reclaim).
Rename it to root_reclaim() in an attempt to make it less ambiguous, and
add documentation to it as well as cgroup_reclaim.
Link: https://lkml.kernel.org/r/20230621023053.432374-1-yosryahmed@google.com
Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Reported-by: Johannes Weiner <hannes@cmpxchg.org>
Closes: https://lore.kernel.org/lkml/20230405200150.GA35884@cmpxchg.org/
Acked-by: Yu Zhao <yuzhao@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
