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3 years agokhugepaged: use helper khugepaged_test_exit() in __khugepaged_enter()
Miaohe Lin [Wed, 5 May 2021 01:33:43 +0000 (18:33 -0700)]
khugepaged: use helper khugepaged_test_exit() in __khugepaged_enter()

Commit 1c8e01d37f7e ("mm: remove the now-unnecessary mmget_still_valid()
hack") have made khugepaged_test_exit() suitable for check mm->mm_users
against 0.  Use this helper here.

Link: https://lkml.kernel.org/r/20210306032947.35921-4-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Ebru Akagunduz <ebru.akagunduz@gmail.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agokhugepaged: reuse the smp_wmb() inside __SetPageUptodate()
Miaohe Lin [Wed, 5 May 2021 01:33:40 +0000 (18:33 -0700)]
khugepaged: reuse the smp_wmb() inside __SetPageUptodate()

smp_wmb() is needed to avoid the copy_huge_page writes to become visible
after the set_pmd_at() write here.  But we can reuse the smp_wmb() inside
__SetPageUptodate() to remove this redundant one.

Link: https://lkml.kernel.org/r/20210306032947.35921-3-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Ebru Akagunduz <ebru.akagunduz@gmail.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agokhugepaged: remove unneeded return value of khugepaged_collapse_pte_mapped_thps()
Miaohe Lin [Wed, 5 May 2021 01:33:37 +0000 (18:33 -0700)]
khugepaged: remove unneeded return value of khugepaged_collapse_pte_mapped_thps()

Patch series "Cleanup and fixup for khugepaged", v2.

This series contains cleanups to remove unneeded return value, use
helper function and so on.  And there is one fix to correct the wrong
result value for trace_mm_collapse_huge_page_isolate().

This patch (of 4):

The return value of khugepaged_collapse_pte_mapped_thps() is never checked
since it's introduced.  We should remove such unneeded return value.

Link: https://lkml.kernel.org/r/20210306032947.35921-1-linmiaohe@huawei.com
Link: https://lkml.kernel.org/r/20210306032947.35921-2-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Ebru Akagunduz <ebru.akagunduz@gmail.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/hugetlb: avoid calculating fault_mutex_hash in truncate_op case
Miaohe Lin [Wed, 5 May 2021 01:33:34 +0000 (18:33 -0700)]
mm/hugetlb: avoid calculating fault_mutex_hash in truncate_op case

The fault_mutex hashing overhead can be avoided in truncate_op case
because page faults can not race with truncation in this routine.

So calculate hash for fault_mutex only in !truncate_op case to save some
cpu cycles.

Link: https://lkml.kernel.org/r/20210308112809.26107-6-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/hugetlb: simplify the code when alloc_huge_page() failed in hugetlb_no_page()
Miaohe Lin [Wed, 5 May 2021 01:33:31 +0000 (18:33 -0700)]
mm/hugetlb: simplify the code when alloc_huge_page() failed in hugetlb_no_page()

Rework the error handling code when alloc_huge_page() failed to remove
some duplicated code and simplify the code slightly.

Link: https://lkml.kernel.org/r/20210308112809.26107-5-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/hugetlb_cgroup: remove unnecessary VM_BUG_ON_PAGE in hugetlb_cgroup_migrate()
Miaohe Lin [Wed, 5 May 2021 01:33:28 +0000 (18:33 -0700)]
mm/hugetlb_cgroup: remove unnecessary VM_BUG_ON_PAGE in hugetlb_cgroup_migrate()

!PageHuge(oldhpage) is implicitly checked in page_hstate() above, so we
remove this explicit one.

Link: https://lkml.kernel.org/r/20210308112809.26107-4-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/hugetlb: optimize the surplus state transfer code in move_hugetlb_state()
Miaohe Lin [Wed, 5 May 2021 01:33:25 +0000 (18:33 -0700)]
mm/hugetlb: optimize the surplus state transfer code in move_hugetlb_state()

We should not transfer the per-node surplus state when we do not cross the
node in order to save some cpu cycles

Link: https://lkml.kernel.org/r/20210308112809.26107-3-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/hugetlb: use some helper functions to cleanup code
Miaohe Lin [Wed, 5 May 2021 01:33:22 +0000 (18:33 -0700)]
mm/hugetlb: use some helper functions to cleanup code

Patch series "Some cleanups for hugetlb".

This series contains cleanups to remove unnecessary VM_BUG_ON_PAGE, use
helper function and so on.  I also collect some previous patches into this
series in case they are forgotten.

This patch (of 5):

We could use pages_per_huge_page to get the number of pages per hugepage,
use get_hstate_idx to calculate hstate index, and use hstate_is_gigantic
to check if a hstate is gigantic to make code more succinct.

Link: https://lkml.kernel.org/r/20210308112809.26107-1-linmiaohe@huawei.com
Link: https://lkml.kernel.org/r/20210308112809.26107-2-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm: generalize HUGETLB_PAGE_SIZE_VARIABLE
Anshuman Khandual [Wed, 5 May 2021 01:33:19 +0000 (18:33 -0700)]
mm: generalize HUGETLB_PAGE_SIZE_VARIABLE

HUGETLB_PAGE_SIZE_VARIABLE need not be defined for each individual
platform subscribing it.  Instead just make it generic.

Link: https://lkml.kernel.org/r/1614914928-22039-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Suggested-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> [powerpc]
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/hugetlb: remove redundant reservation check condition in alloc_huge_page()
Miaohe Lin [Wed, 5 May 2021 01:33:16 +0000 (18:33 -0700)]
mm/hugetlb: remove redundant reservation check condition in alloc_huge_page()

vma_resv_map(vma) checks if a reserve map is associated with the vma.
The routine vma_needs_reservation() will check vma_resv_map(vma) and
return 1 if no reserv map is present.  map_chg is set to the return
value of vma_needs_reservation().  Therefore, !vma_resv_map(vma) is
redundant in the expression:

map_chg || avoid_reserve || !vma_resv_map(vma);

Remove the redundant check.

[Thanks Mike Kravetz for reshaping this commit message!]

Link: https://lkml.kernel.org/r/20210301104726.45159-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agohugetlb/userfaultfd: unshare all pmds for hugetlbfs when register wp
Peter Xu [Wed, 5 May 2021 01:33:13 +0000 (18:33 -0700)]
hugetlb/userfaultfd: unshare all pmds for hugetlbfs when register wp

Huge pmd sharing for hugetlbfs is racy with userfaultfd-wp because
userfaultfd-wp is always based on pgtable entries, so they cannot be
shared.

Walk the hugetlb range and unshare all such mappings if there is, right
before UFFDIO_REGISTER will succeed and return to userspace.

This will pair with want_pmd_share() in hugetlb code so that huge pmd
sharing is completely disabled for userfaultfd-wp registered range.

Link: https://lkml.kernel.org/r/20210218231206.15524-1-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Adam Ruprecht <ruprecht@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Cannon Matthews <cannonmatthews@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chinwen Chang <chinwen.chang@mediatek.com>
Cc: David Rientjes <rientjes@google.com>
Cc: "Dr . David Alan Gilbert" <dgilbert@redhat.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Lokesh Gidra <lokeshgidra@google.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Michal Koutn" <mkoutny@suse.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oliver Upton <oupton@google.com>
Cc: Shaohua Li <shli@fb.com>
Cc: Shawn Anastasio <shawn@anastas.io>
Cc: Steven Price <steven.price@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/hugetlb: move flush_hugetlb_tlb_range() into hugetlb.h
Peter Xu [Wed, 5 May 2021 01:33:08 +0000 (18:33 -0700)]
mm/hugetlb: move flush_hugetlb_tlb_range() into hugetlb.h

Prepare for it to be called outside of mm/hugetlb.c.

Link: https://lkml.kernel.org/r/20210218231204.15474-1-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Axel Rasmussen <axelrasmussen@google.com>
Cc: Adam Ruprecht <ruprecht@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Cannon Matthews <cannonmatthews@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chinwen Chang <chinwen.chang@mediatek.com>
Cc: David Rientjes <rientjes@google.com>
Cc: "Dr . David Alan Gilbert" <dgilbert@redhat.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Lokesh Gidra <lokeshgidra@google.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Michal Koutn" <mkoutny@suse.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oliver Upton <oupton@google.com>
Cc: Shaohua Li <shli@fb.com>
Cc: Shawn Anastasio <shawn@anastas.io>
Cc: Steven Price <steven.price@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agohugetlb/userfaultfd: forbid huge pmd sharing when uffd enabled
Peter Xu [Wed, 5 May 2021 01:33:04 +0000 (18:33 -0700)]
hugetlb/userfaultfd: forbid huge pmd sharing when uffd enabled

Huge pmd sharing could bring problem to userfaultfd.  The thing is that
userfaultfd is running its logic based on the special bits on page table
entries, however the huge pmd sharing could potentially share page table
entries for different address ranges.  That could cause issues on
either:

 - When sharing huge pmd page tables for an uffd write protected range,
   the newly mapped huge pmd range will also be write protected
   unexpectedly, or,

 - When we try to write protect a range of huge pmd shared range, we'll
   first do huge_pmd_unshare() in hugetlb_change_protection(), however
   that also means the UFFDIO_WRITEPROTECT could be silently skipped for
   the shared region, which could lead to data loss.

While at it, a few other things are done altogether:

 - Move want_pmd_share() from mm/hugetlb.c into linux/hugetlb.h, because
   that's definitely something that arch code would like to use too

 - ARM64 currently directly check against
   CONFIG_ARCH_WANT_HUGE_PMD_SHARE when trying to share huge pmd. Switch
   to the want_pmd_share() helper.

 - Move vma_shareable() from huge_pmd_share() into want_pmd_share().

[peterx@redhat.com: fix build with !ARCH_WANT_HUGE_PMD_SHARE]
Link: https://lkml.kernel.org/r/20210310185359.88297-1-peterx@redhat.com
Link: https://lkml.kernel.org/r/20210218231202.15426-1-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Axel Rasmussen <axelrasmussen@google.com>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Cc: Adam Ruprecht <ruprecht@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Cannon Matthews <cannonmatthews@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chinwen Chang <chinwen.chang@mediatek.com>
Cc: David Rientjes <rientjes@google.com>
Cc: "Dr . David Alan Gilbert" <dgilbert@redhat.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Lokesh Gidra <lokeshgidra@google.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Michal Koutn" <mkoutny@suse.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oliver Upton <oupton@google.com>
Cc: Shaohua Li <shli@fb.com>
Cc: Shawn Anastasio <shawn@anastas.io>
Cc: Steven Price <steven.price@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agohugetlb: pass vma into huge_pte_alloc() and huge_pmd_share()
Peter Xu [Wed, 5 May 2021 01:33:00 +0000 (18:33 -0700)]
hugetlb: pass vma into huge_pte_alloc() and huge_pmd_share()

Patch series "hugetlb: Disable huge pmd unshare for uffd-wp", v4.

This series tries to disable huge pmd unshare of hugetlbfs backed memory
for uffd-wp.  Although uffd-wp of hugetlbfs is still during rfc stage,
the idea of this series may be needed for multiple tasks (Axel's uffd
minor fault series, and Mike's soft dirty series), so I picked it out
from the larger series.

This patch (of 4):

It is a preparation work to be able to behave differently in the per
architecture huge_pte_alloc() according to different VMA attributes.

Pass it deeper into huge_pmd_share() so that we can avoid the find_vma() call.

[peterx@redhat.com: build fix]
Link: https://lkml.kernel.org/r/20210304164653.GB397383@xz-x1Link:
Link: https://lkml.kernel.org/r/20210218230633.15028-2-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Suggested-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Adam Ruprecht <ruprecht@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Cannon Matthews <cannonmatthews@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chinwen Chang <chinwen.chang@mediatek.com>
Cc: David Rientjes <rientjes@google.com>
Cc: "Dr . David Alan Gilbert" <dgilbert@redhat.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Lokesh Gidra <lokeshgidra@google.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Michal Koutn" <mkoutny@suse.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oliver Upton <oupton@google.com>
Cc: Shaohua Li <shli@fb.com>
Cc: Shawn Anastasio <shawn@anastas.io>
Cc: Steven Price <steven.price@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm: remove nrexceptional from inode: remove BUG_ON
Hugh Dickins [Wed, 5 May 2021 01:32:57 +0000 (18:32 -0700)]
mm: remove nrexceptional from inode: remove BUG_ON

clear_inode()'s BUG_ON(!mapping_empty(&inode->i_data)) is unsafe: we
know of two ways in which nodes can and do (on rare occasions) get left
behind.  Until those are fixed, do not BUG_ON() nor even WARN_ON().

Yes, this will then leak those nodes (or the next user of the struct
inode may use them); but this has been happening for years, and the new
BUG_ON(!mapping_empty) was only guilty of revealing that.  A proper fix
will follow, but no hurry.

Link: https://lkml.kernel.org/r/alpine.LSU.2.11.2104292229380.16080@eggly.anvils
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm: remove nrexceptional from inode
Matthew Wilcox (Oracle) [Wed, 5 May 2021 01:32:54 +0000 (18:32 -0700)]
mm: remove nrexceptional from inode

We no longer track anything in nrexceptional, so remove it, saving 8 bytes
per inode.

Link: https://lkml.kernel.org/r/20201026151849.24232-5-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Vishal Verma <vishal.l.verma@intel.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agodax: account DAX entries as nrpages
Matthew Wilcox (Oracle) [Wed, 5 May 2021 01:32:51 +0000 (18:32 -0700)]
dax: account DAX entries as nrpages

Simplify mapping_needs_writeback() by accounting DAX entries as pages
instead of exceptional entries.

Link: https://lkml.kernel.org/r/20201026151849.24232-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Vishal Verma <vishal.l.verma@intel.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm: stop accounting shadow entries
Matthew Wilcox (Oracle) [Wed, 5 May 2021 01:32:48 +0000 (18:32 -0700)]
mm: stop accounting shadow entries

We no longer need to keep track of how many shadow entries are present in
a mapping.  This saves a few writes to the inode and memory barriers.

Link: https://lkml.kernel.org/r/20201026151849.24232-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Vishal Verma <vishal.l.verma@intel.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm: introduce and use mapping_empty()
Matthew Wilcox (Oracle) [Wed, 5 May 2021 01:32:45 +0000 (18:32 -0700)]
mm: introduce and use mapping_empty()

Patch series "Remove nrexceptional tracking", v2.

We actually use nrexceptional for very little these days.  It's a minor
pain to keep in sync with nrpages, but the pain becomes much bigger with
the THP patches because we don't know how many indices a shadow entry
occupies.  It's easier to just remove it than keep it accurate.

Also, we save 8 bytes per inode which is nothing to sneeze at; on my
laptop, it would improve shmem_inode_cache from 22 to 23 objects per
16kB, and inode_cache from 26 to 27 objects.  Combined, that saves
a megabyte of memory from a combined usage of 25MB for both caches.
Unfortunately, ext4 doesn't cross a magic boundary, so it doesn't save
any memory for ext4.

This patch (of 4):

Instead of checking the two counters (nrpages and nrexceptional), we can
just check whether i_pages is empty.

Link: https://lkml.kernel.org/r/20201026151849.24232-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20201026151849.24232-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Vishal Verma <vishal.l.verma@intel.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/memory-failure: unnecessary amount of unmapping
Jane Chu [Fri, 30 Apr 2021 06:02:19 +0000 (23:02 -0700)]
mm/memory-failure: unnecessary amount of unmapping

It appears that unmap_mapping_range() actually takes a 'size' as its third
argument rather than a location, the current calling fashion causes
unnecessary amount of unmapping to occur.

Link: https://lkml.kernel.org/r/20210420002821.2749748-1-jane.chu@oracle.com
Fixes: 7aac46741c35e ("mm, memory_failure: Teach memory_failure() about dev_pagemap pages")
Signed-off-by: Jane Chu <jane.chu@oracle.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/mmzone.h: fix existing kernel-doc comments and link them to core-api
Mike Rapoport [Fri, 30 Apr 2021 06:02:16 +0000 (23:02 -0700)]
mm/mmzone.h: fix existing kernel-doc comments and link them to core-api

There are a couple of kernel-doc comments in include/linux/mmzone.h but
they have minor formatting issues that would cause kernel-doc warnings.

Fix the formatting of those comments, add missing Return: descriptions and
link include/linux/mmzone.h to Documentation/core-api/mm-api.rst

Link: https://lkml.kernel.org/r/20210426141927.1314326-2-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm: page_alloc: ignore init_on_free=1 for debug_pagealloc=1
Sergei Trofimovich [Fri, 30 Apr 2021 06:02:11 +0000 (23:02 -0700)]
mm: page_alloc: ignore init_on_free=1 for debug_pagealloc=1

On !ARCH_SUPPORTS_DEBUG_PAGEALLOC (like ia64) debug_pagealloc=1 implies
page_poison=on:

    if (page_poisoning_enabled() ||
         (!IS_ENABLED(CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC) &&
          debug_pagealloc_enabled()))
            static_branch_enable(&_page_poisoning_enabled);

page_poison=on needs to override init_on_free=1.

Before the change it did not work as expected for the following case:
- have PAGE_POISONING=y
- have page_poison unset
- have !ARCH_SUPPORTS_DEBUG_PAGEALLOC arch (like ia64)
- have init_on_free=1
- have debug_pagealloc=1

That way we get both keys enabled:
- static_branch_enable(&init_on_free);
- static_branch_enable(&_page_poisoning_enabled);

which leads to poisoned pages returned for __GFP_ZERO pages.

After the change we execute only:
- static_branch_enable(&_page_poisoning_enabled);
  and ignore init_on_free=1.

Link: https://lkml.kernel.org/r/20210329222555.3077928-1-slyfox@gentoo.org
Link: https://lkml.org/lkml/2021/3/26/443
Fixes: 016c9a64fda9 ("mm, page_poison: use static key more efficiently")
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agonet: page_pool: use alloc_pages_bulk in refill code path
Jesper Dangaard Brouer [Fri, 30 Apr 2021 06:02:07 +0000 (23:02 -0700)]
net: page_pool: use alloc_pages_bulk in refill code path

There are cases where the page_pool need to refill with pages from the
page allocator.  Some workloads cause the page_pool to release pages
instead of recycling these pages.

For these workload it can improve performance to bulk alloc pages from the
page-allocator to refill the alloc cache.

For XDP-redirect workload with 100G mlx5 driver (that use page_pool)
redirecting xdp_frame packets into a veth, that does XDP_PASS to create an
SKB from the xdp_frame, which then cannot return the page to the
page_pool.

Performance results under GitHub xdp-project[1]:
 [1] https://github.com/xdp-project/xdp-project/blob/master/areas/mem/page_pool06_alloc_pages_bulk.org

Mel: The patch "net: page_pool: convert to use alloc_pages_bulk_array
variant" was squashed with this patch. From the test page, the array
variant was superior with one of the test results as follows.

Kernel XDP stats       CPU     pps           Delta
Baseline XDP-RX CPU      total   3,771,046       n/a
List XDP-RX CPU      total   3,940,242    +4.49%
Array XDP-RX CPU      total   4,249,224   +12.68%

Link: https://lkml.kernel.org/r/20210325114228.27719-10-mgorman@techsingularity.net
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Alexander Lobakin <alobakin@pm.me>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: David Miller <davem@davemloft.net>
Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agonet: page_pool: refactor dma_map into own function page_pool_dma_map
Jesper Dangaard Brouer [Fri, 30 Apr 2021 06:02:04 +0000 (23:02 -0700)]
net: page_pool: refactor dma_map into own function page_pool_dma_map

In preparation for next patch, move the dma mapping into its own function,
as this will make it easier to follow the changes.

[ilias.apalodimas: make page_pool_dma_map return boolean]

Link: https://lkml.kernel.org/r/20210325114228.27719-9-mgorman@techsingularity.net
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Alexander Lobakin <alobakin@pm.me>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: David Miller <davem@davemloft.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agoSUNRPC: refresh rq_pages using a bulk page allocator
Chuck Lever [Fri, 30 Apr 2021 06:02:01 +0000 (23:02 -0700)]
SUNRPC: refresh rq_pages using a bulk page allocator

Reduce the rate at which nfsd threads hammer on the page allocator.  This
improves throughput scalability by enabling the threads to run more
independently of each other.

[mgorman: Update interpretation of alloc_pages_bulk return value]

Link: https://lkml.kernel.org/r/20210325114228.27719-8-mgorman@techsingularity.net
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Alexander Lobakin <alobakin@pm.me>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David Miller <davem@davemloft.net>
Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agoSUNRPC: set rq_page_end differently
Chuck Lever [Fri, 30 Apr 2021 06:01:58 +0000 (23:01 -0700)]
SUNRPC: set rq_page_end differently

Patch series "SUNRPC consumer for the bulk page allocator"

This patch set and the measurements below are based on yesterday's
bulk allocator series:

  git://git.kernel.org/pub/scm/linux/kernel/git/mel/linux.git mm-bulk-rebase-v5r9

The patches change SUNRPC to invoke the array-based bulk allocator
instead of alloc_page().

The micro-benchmark results are promising.  I ran a mixture of 256KB
reads and writes over NFSv3.  The server's kernel is built with KASAN
enabled, so the comparison is exaggerated but I believe it is still
valid.

I instrumented svc_recv() to measure the latency of each call to
svc_alloc_arg() and report it via a trace point.  The following results
are averages across the trace events.

  Single page: 25.007 us per call over 532,571 calls
  Bulk list:    6.258 us per call over 517,034 calls
  Bulk array:   4.590 us per call over 517,442 calls

This patch (of 2)

Refactor:

I'm about to use the loop variable @i for something else.

As far as the "i++" is concerned, that is a post-increment. The
value of @i is not used subsequently, so the increment operator
is unnecessary and can be removed.

Also note that nfsd_read_actor() was renamed nfsd_splice_actor()
by commit e2dcdb477d84 ("sendfile: convert nfsd to
splice_direct_to_actor()").

Link: https://lkml.kernel.org/r/20210325114228.27719-7-mgorman@techsingularity.net
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Alexander Lobakin <alobakin@pm.me>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David Miller <davem@davemloft.net>
Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/page_alloc: inline __rmqueue_pcplist
Jesper Dangaard Brouer [Fri, 30 Apr 2021 06:01:55 +0000 (23:01 -0700)]
mm/page_alloc: inline __rmqueue_pcplist

When __alloc_pages_bulk() got introduced two callers of __rmqueue_pcplist
exist and the compiler chooses to not inline this function.

  ./scripts/bloat-o-meter vmlinux-before vmlinux-inline__rmqueue_pcplist
  add/remove: 0/1 grow/shrink: 2/0 up/down: 164/-125 (39)
  Function                                     old     new   delta
  rmqueue                                     2197    2296     +99
  __alloc_pages_bulk                          1921    1986     +65
  __rmqueue_pcplist                            125       -    -125
  Total: Before=19374127, After=19374166, chg +0.00%

modprobe page_bench04_bulk loops=$((10**7))

Type:time_bulk_page_alloc_free_array
 -  Per elem: 106 cycles(tsc) 29.595 ns (step:64)
 - (measurement period time:0.295955434 sec time_interval:295955434)
 - (invoke count:10000000 tsc_interval:1065447105)

Before:
 - Per elem: 110 cycles(tsc) 30.633 ns (step:64)

Link: https://lkml.kernel.org/r/20210325114228.27719-6-mgorman@techsingularity.net
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Alexander Lobakin <alobakin@pm.me>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: David Miller <davem@davemloft.net>
Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/page_alloc: optimize code layout for __alloc_pages_bulk
Jesper Dangaard Brouer [Fri, 30 Apr 2021 06:01:51 +0000 (23:01 -0700)]
mm/page_alloc: optimize code layout for __alloc_pages_bulk

Looking at perf-report and ASM-code for __alloc_pages_bulk() it is clear
that the code activated is suboptimal.  The compiler guesses wrong and
places unlikely code at the beginning.  Due to the use of WARN_ON_ONCE()
macro the UD2 asm instruction is added to the code, which confuse the
I-cache prefetcher in the CPU.

[mgorman@techsingularity.net: minor changes and rebasing]

Link: https://lkml.kernel.org/r/20210325114228.27719-5-mgorman@techsingularity.net
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Alexander Lobakin <alobakin@pm.me>
Acked-By: Vlastimil Babka <vbabka@suse.cz>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: David Miller <davem@davemloft.net>
Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/page_alloc: add an array-based interface to the bulk page allocator
Mel Gorman [Fri, 30 Apr 2021 06:01:48 +0000 (23:01 -0700)]
mm/page_alloc: add an array-based interface to the bulk page allocator

The proposed callers for the bulk allocator store pages from the bulk
allocator in an array.  This patch adds an array-based interface to the
API to avoid multiple list iterations.  The page list interface is
preserved to avoid requiring all users of the bulk API to allocate and
manage enough storage to store the pages.

[akpm@linux-foundation.org: remove now unused local `allocated']

Link: https://lkml.kernel.org/r/20210325114228.27719-4-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Alexander Lobakin <alobakin@pm.me>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: David Miller <davem@davemloft.net>
Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/page_alloc: add a bulk page allocator
Mel Gorman [Fri, 30 Apr 2021 06:01:45 +0000 (23:01 -0700)]
mm/page_alloc: add a bulk page allocator

This patch adds a new page allocator interface via alloc_pages_bulk, and
__alloc_pages_bulk_nodemask.  A caller requests a number of pages to be
allocated and added to a list.

The API is not guaranteed to return the requested number of pages and
may fail if the preferred allocation zone has limited free memory, the
cpuset changes during the allocation or page debugging decides to fail
an allocation.  It's up to the caller to request more pages in batch if
necessary.

Note that this implementation is not very efficient and could be
improved but it would require refactoring.  The intent is to make it
available early to determine what semantics are required by different
callers.  Once the full semantics are nailed down, it can be refactored.

[mgorman@techsingularity.net: fix alloc_pages_bulk() return type, per Matthew]
Link: https://lkml.kernel.org/r/20210325123713.GQ3697@techsingularity.net
[mgorman@techsingularity.net: fix uninit var warning]
Link: https://lkml.kernel.org/r/20210330114847.GX3697@techsingularity.net
[mgorman@techsingularity.net: fix comment, per Vlastimil]
Link: https://lkml.kernel.org/r/20210412110255.GV3697@techsingularity.net
Link: https://lkml.kernel.org/r/20210325114228.27719-3-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Alexander Lobakin <alobakin@pm.me>
Tested-by: Colin Ian King <colin.king@canonical.com>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: David Miller <davem@davemloft.net>
Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/page_alloc: rename alloced to allocated
Mel Gorman [Fri, 30 Apr 2021 06:01:42 +0000 (23:01 -0700)]
mm/page_alloc: rename alloced to allocated

Patch series "Introduce a bulk order-0 page allocator with two in-tree users", v6.

This series introduces a bulk order-0 page allocator with sunrpc and the
network page pool being the first users.  The implementation is not
efficient as semantics needed to be ironed out first.  If no other
semantic changes are needed, it can be made more efficient.  Despite that,
this is a performance-related for users that require multiple pages for an
operation without multiple round-trips to the page allocator.  Quoting the
last patch for the high-speed networking use-case

            Kernel          XDP stats       CPU     pps           Delta
            Baseline        XDP-RX CPU      total   3,771,046       n/a
            List            XDP-RX CPU      total   3,940,242    +4.49%
            Array           XDP-RX CPU      total   4,249,224   +12.68%

Via the SUNRPC traces of svc_alloc_arg()

Single page: 25.007 us per call over 532,571 calls
Bulk list:    6.258 us per call over 517,034 calls
Bulk array:   4.590 us per call over 517,442 calls

Both potential users in this series are corner cases (NFS and high-speed
networks) so it is unlikely that most users will see any benefit in the
short term.  Other potential other users are batch allocations for page
cache readahead, fault around and SLUB allocations when high-order pages
are unavailable.  It's unknown how much benefit would be seen by
converting multiple page allocation calls to a single batch or what
difference it may make to headline performance.

Light testing of my own running dbench over NFS passed.  Chuck and Jesper
conducted their own tests and details are included in the changelogs.

Patch 1 renames a variable name that is particularly unpopular

Patch 2 adds a bulk page allocator

Patch 3 adds an array-based version of the bulk allocator

Patches 4-5 adds micro-optimisations to the implementation

Patches 6-7 SUNRPC user

Patches 8-9 Network page_pool user

This patch (of 9):

Review feedback of the bulk allocator twice found problems with "alloced"
being a counter for pages allocated.  The naming was based on the API name
"alloc" and was based on the idea that verbal communication about malloc
tends to use the fake word "malloced" instead of the fake word mallocated.
To be consistent, this preparation patch renames alloced to allocated in
rmqueue_bulk so the bulk allocator and per-cpu allocator use similar names
when the bulk allocator is introduced.

Link: https://lkml.kernel.org/r/20210325114228.27719-1-mgorman@techsingularity.net
Link: https://lkml.kernel.org/r/20210325114228.27719-2-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Alexander Lobakin <alobakin@pm.me>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/page_alloc: duplicate include linux/vmalloc.h
zhouchuangao [Fri, 30 Apr 2021 06:01:39 +0000 (23:01 -0700)]
mm/page_alloc: duplicate include linux/vmalloc.h

linux/vmalloc.h is repeatedly in the file page_alloc.c

Link: https://lkml.kernel.org/r/1616468751-80656-1-git-send-email-zhouchuangao@vivo.com
Signed-off-by: zhouchuangao <zhouchuangao@vivo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm, page_alloc: avoid page_to_pfn() in move_freepages()
Kefeng Wang [Fri, 30 Apr 2021 06:01:36 +0000 (23:01 -0700)]
mm, page_alloc: avoid page_to_pfn() in move_freepages()

The start_pfn and end_pfn are already available in move_freepages_block(),
there is no need to go back and forth between page and pfn in
move_freepages and move_freepages_block, and pfn_valid_within() should
validate pfn first before touching the page.

Link: https://lkml.kernel.org/r/20210323131215.934472-1-liushixin2@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/Kconfig: remove default DISCONTIGMEM_MANUAL
Geert Uytterhoeven [Fri, 30 Apr 2021 06:01:33 +0000 (23:01 -0700)]
mm/Kconfig: remove default DISCONTIGMEM_MANUAL

Commit 448d2250adbd0701 ("ia64: make SPARSEMEM default and disable
DISCONTIGMEM") removed the last enabler of ARCH_DISCONTIGMEM_DEFAULT,
hence the memory model can no longer default to DISCONTIGMEM_MANUAL.

Link: https://lkml.kernel.org/r/20210312141208.3465520-1-geert@linux-m68k.org
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm: page_alloc: dump migrate-failed pages
Minchan Kim [Fri, 30 Apr 2021 06:01:30 +0000 (23:01 -0700)]
mm: page_alloc: dump migrate-failed pages

Currently, debugging CMA allocation failures is quite limited.  The most
common source of these failures seems to be page migration which doesn't
provide any useful information on the reason of the failure by itself.
alloc_contig_range can report those failures as it holds a list of
migrate-failed pages.

The information logged by dump_page() has already proven helpful for
debugging allocation issues, like identifying long-term pinnings on
ZONE_MOVABLE or MIGRATE_CMA.

Let's use the dynamic debugging infrastructure, such that we avoid
flooding the logs and creating a lot of noise on frequent
alloc_contig_range() calls.  This information is helpful for debugging
only.

There are two ifdefery conditions to support common dyndbg options:

 - CONFIG_DYNAMIC_DEBUG_CORE && DYNAMIC_DEBUG_MODULE
   It aims for supporting the feature with only specific file with
   adding ccflags.

 - CONFIG_DYNAMIC_DEBUG
   It aims for supporting the feature with system wide globally.

A simple example to enable the feature:

Admin could enable the dump like this(by default, disabled)

echo "func alloc_contig_dump_pages +p" > control

Admin could disable it.

echo "func alloc_contig_dump_pages =_" > control

Detail goes Documentation/admin-guide/dynamic-debug-howto.rst

A concern is utility functions in dump_page use inconsistent
loglevels. In the future, we might want to make the loglevels
used inside dump_page() consistent and eventually rework the way
we log the information here. See [1].

[1] https://lore.kernel.org/linux-mm/YEh4doXvyuRl5BDB@google.com/

Link: https://lkml.kernel.org/r/20210311194042.825152-1-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: John Dias <joaodias@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jason Baron <jbaron@akamai.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/mempolicy: fix mpol_misplaced kernel-doc
Matthew Wilcox (Oracle) [Fri, 30 Apr 2021 06:01:27 +0000 (23:01 -0700)]
mm/mempolicy: fix mpol_misplaced kernel-doc

Sphinx interprets the Return section as a list and complains about it.
Turn it into a sentence and move it to the end of the kernel-doc to fit
the kernel-doc style.

Link: https://lkml.kernel.org/r/20210225150642.2582252-8-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/mempolicy: rewrite alloc_pages_vma documentation
Matthew Wilcox (Oracle) [Fri, 30 Apr 2021 06:01:24 +0000 (23:01 -0700)]
mm/mempolicy: rewrite alloc_pages_vma documentation

The current formatting doesn't quite work with kernel-doc.

Link: https://lkml.kernel.org/r/20210225150642.2582252-7-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/mempolicy: rewrite alloc_pages documentation
Matthew Wilcox (Oracle) [Fri, 30 Apr 2021 06:01:21 +0000 (23:01 -0700)]
mm/mempolicy: rewrite alloc_pages documentation

Document alloc_pages() for both NUMA and non-NUMA cases as kernel-doc
doesn't care.

Link: https://lkml.kernel.org/r/20210225150642.2582252-6-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/mempolicy: rename alloc_pages_current to alloc_pages
Matthew Wilcox (Oracle) [Fri, 30 Apr 2021 06:01:18 +0000 (23:01 -0700)]
mm/mempolicy: rename alloc_pages_current to alloc_pages

When CONFIG_NUMA is enabled, alloc_pages() is a wrapper around
alloc_pages_current().  This is pointless, just implement alloc_pages()
directly.

Link: https://lkml.kernel.org/r/20210225150642.2582252-5-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/page_alloc: combine __alloc_pages and __alloc_pages_nodemask
Matthew Wilcox (Oracle) [Fri, 30 Apr 2021 06:01:15 +0000 (23:01 -0700)]
mm/page_alloc: combine __alloc_pages and __alloc_pages_nodemask

There are only two callers of __alloc_pages() so prune the thicket of
alloc_page variants by combining the two functions together.  Current
callers of __alloc_pages() simply add an extra 'NULL' parameter and
current callers of __alloc_pages_nodemask() call __alloc_pages() instead.

Link: https://lkml.kernel.org/r/20210225150642.2582252-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/page_alloc: rename gfp_mask to gfp
Matthew Wilcox (Oracle) [Fri, 30 Apr 2021 06:01:13 +0000 (23:01 -0700)]
mm/page_alloc: rename gfp_mask to gfp

Shorten some overly-long lines by renaming this identifier.

Link: https://lkml.kernel.org/r/20210225150642.2582252-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/page_alloc: rename alloc_mask to alloc_gfp
Matthew Wilcox (Oracle) [Fri, 30 Apr 2021 06:01:10 +0000 (23:01 -0700)]
mm/page_alloc: rename alloc_mask to alloc_gfp

Patch series "Rationalise __alloc_pages wrappers", v3.

I was poking around the __alloc_pages variants trying to understand why
they each exist, and couldn't really find a good justification for keeping
__alloc_pages and __alloc_pages_nodemask as separate functions.  That led
to getting rid of alloc_pages_current() and then I noticed the
documentation was bad, and then I noticed the mempolicy documentation
wasn't included.

Anyway, this is all cleanups & doc fixes.

This patch (of 7):

We have two masks involved -- the nodemask and the gfp mask, so alloc_mask
is an unclear name.

Link: https://lkml.kernel.org/r/20210225150642.2582252-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agoinclude/linux/page-flags-layout.h: cleanups
Yu Zhao [Fri, 30 Apr 2021 06:01:07 +0000 (23:01 -0700)]
include/linux/page-flags-layout.h: cleanups

Tidy things up and delete comments stating the obvious with typos or
making no sense.

Link: https://lkml.kernel.org/r/20210303071609.797782-2-yuzhao@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agoinclude/linux/page-flags-layout.h: correctly determine LAST_CPUPID_WIDTH
Yu Zhao [Fri, 30 Apr 2021 06:01:04 +0000 (23:01 -0700)]
include/linux/page-flags-layout.h: correctly determine LAST_CPUPID_WIDTH

The naming convention used in include/linux/page-flags-layout.h:
  *_SHIFT: the number of bits trying to allocate
  *_WIDTH: the number of bits successfully allocated

So when it comes to LAST_CPUPID_WIDTH, we need to check whether all
previous *_WIDTH and LAST_CPUPID_SHIFT can fit into page flags. This
means we need to use NODES_WIDTH, not NODES_SHIFT.

Link: https://lkml.kernel.org/r/20210303071609.797782-1-yuzhao@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm: remove lru_add_drain_all in alloc_contig_range
Minchan Kim [Fri, 30 Apr 2021 06:01:01 +0000 (23:01 -0700)]
mm: remove lru_add_drain_all in alloc_contig_range

__alloc_contig_migrate_range already has lru_add_drain_all call via
migrate_prep.  It's necessary to move LRU taget pages into LRU list to be
able to isolated.  However, lru_add_drain_all call after
__alloc_contig_migrate_range is pointless since it has changed source page
freeing from putback_lru_pages to put_page[1].

This patch removes it.

[1] 6a24a175e594, ("mm: use put_page() to free page instead of putback_lru_page()"

Link: https://lkml.kernel.org/r/20210303204512.2863087-1-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/page_alloc: drop pr_info_ratelimited() in alloc_contig_range()
David Hildenbrand [Fri, 30 Apr 2021 06:00:58 +0000 (23:00 -0700)]
mm/page_alloc: drop pr_info_ratelimited() in alloc_contig_range()

The information that some PFNs are busy is:

a) not helpful for ordinary users: we don't even know *who* called
   alloc_contig_range(). This is certainly not worth a pr_info.*().

b) not really helpful for debugging: we don't have any details *why*
   these PFNs are busy, and that is what we usually care about.

c) not complete: there are other cases where we fail alloc_contig_range()
   using different paths that are not getting recorded.

For example, we reach this path once we succeeded in isolating pageblocks,
but failed to migrate some pages - which can happen easily on ZONE_NORMAL
(i.e., has_unmovable_pages() is racy) but also on ZONE_MOVABLE i.e., we
would have to retry longer to migrate).

For example via virtio-mem when unplugging memory, we can create quite
some noise (especially with ZONE_NORMAL) that is not of interest to users
- it's expected that some allocations may fail as memory is busy.

Let's just drop that pr_info_ratelimit() and rather implement a dynamic
debugging mechanism in the future that can give us a better reason why
alloc_contig_range() failed on specific pages.

Link: https://lkml.kernel.org/r/20210301150945.77012-1-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm: move mem_init_print_info() into mm_init()
Kefeng Wang [Fri, 30 Apr 2021 06:00:55 +0000 (23:00 -0700)]
mm: move mem_init_print_info() into mm_init()

mem_init_print_info() is called in mem_init() on each architecture, and
pass NULL argument, so using void argument and move it into mm_init().

Link: https://lkml.kernel.org/r/20210317015210.33641-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com> [x86]
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr> [powerpc]
Acked-by: David Hildenbrand <david@redhat.com>
Tested-by: Anatoly Pugachev <matorola@gmail.com> [sparc64]
Acked-by: Russell King <rmk+kernel@armlinux.org.uk> [arm]
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Guo Ren <guoren@kernel.org>
Cc: Yoshinori Sato <ysato@users.osdn.me>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "Peter Zijlstra" <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agoirq_work: record irq_work_queue() call stack
Zqiang [Fri, 30 Apr 2021 06:00:52 +0000 (23:00 -0700)]
irq_work: record irq_work_queue() call stack

Add the irq_work_queue() call stack into the KASAN auxiliary stack in
order to improve KASAN reports.  this will let us know where the irq work
be queued.

Link: https://lkml.kernel.org/r/20210331063202.28770-1-qiang.zhang@windriver.com
Signed-off-by: Zqiang <qiang.zhang@windriver.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Walter Wu <walter-zh.wu@mediatek.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agokasan: detect false-positives in tests
Andrey Konovalov [Fri, 30 Apr 2021 06:00:49 +0000 (23:00 -0700)]
kasan: detect false-positives in tests

Currently, KASAN-KUnit tests can check that a particular annotated part of
code causes a KASAN report.  However, they do not check that no unwanted
reports happen between the annotated parts.

This patch implements these checks.

It is done by setting report_data.report_found to false in
kasan_test_init() and at the end of KUNIT_EXPECT_KASAN_FAIL() and then
checking that it remains false at the beginning of
KUNIT_EXPECT_KASAN_FAIL() and in kasan_test_exit().

kunit_add_named_resource() call is moved to kasan_test_init(), and the
value of fail_data.report_expected is kept as false in between
KUNIT_EXPECT_KASAN_FAIL() annotations for consistency.

Link: https://lkml.kernel.org/r/48079c52cc329fbc52f4386996598d58022fb872.1617207873.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agokasan: record task_work_add() call stack
Walter Wu [Fri, 30 Apr 2021 06:00:45 +0000 (23:00 -0700)]
kasan: record task_work_add() call stack

Why record task_work_add() call stack?  Syzbot reports many use-after-free
issues for task_work, see [1].  After seeing the free stack and the
current auxiliary stack, we think they are useless, we don't know where
the work was registered.  This work may be the free call stack, so we miss
the root cause and don't solve the use-after-free.

Add the task_work_add() call stack into the KASAN auxiliary stack in order
to improve KASAN reports.  It helps programmers solve use-after-free
issues.

[1]: https://groups.google.com/g/syzkaller-bugs/search?q=kasan%20use-after-free%20task_work_run

Link: https://lkml.kernel.org/r/20210316024410.19967-1-walter-zh.wu@mediatek.com
Signed-off-by: Walter Wu <walter-zh.wu@mediatek.com>
Suggested-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agokasan: docs: update tests section
Andrey Konovalov [Fri, 30 Apr 2021 06:00:42 +0000 (23:00 -0700)]
kasan: docs: update tests section

Update the "Tests" section in KASAN documentation:

 - Add an introductory sentence.

 - Add proper indentation for the list of ways to run KUnit tests.

 - Punctuation, readability, and other minor clean-ups.

Link: https://lkml.kernel.org/r/fb08845e25c8847ffda271fa19cda2621c04a65b.1615559068.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agokasan: docs: update ignoring accesses section
Andrey Konovalov [Fri, 30 Apr 2021 06:00:39 +0000 (23:00 -0700)]
kasan: docs: update ignoring accesses section

Update the "Ignoring accesses" section in KASAN documentation:

 - Mention __no_sanitize_address/noinstr.

 - Mention kasan_disable/enable_current().

 - Mention kasan_reset_tag()/page_kasan_tag_reset().

 - Readability and punctuation clean-ups.

Link: https://lkml.kernel.org/r/4531ba5f3eca61f6aade863c136778cc8c807a64.1615559068.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agokasan: docs: update shadow memory section
Andrey Konovalov [Fri, 30 Apr 2021 06:00:36 +0000 (23:00 -0700)]
kasan: docs: update shadow memory section

Update the "Shadow memory" section in KASAN documentation:

 - Rearrange the introduction paragraph do it doesn't give a
   "KASAN has an issue" impression.

 - Update the list of architectures with vmalloc support.

 - Punctuation, readability, and other minor clean-ups.

Link: https://lkml.kernel.org/r/00f8c38b0fd5290a3f4dced04eaba41383e67e14.1615559068.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agokasan: docs: update HW_TAGS implementation details section
Andrey Konovalov [Fri, 30 Apr 2021 06:00:33 +0000 (23:00 -0700)]
kasan: docs: update HW_TAGS implementation details section

Update the "Implementation details" section for HW_TAGS KASAN:

 - Punctuation, readability, and other minor clean-ups.

Link: https://lkml.kernel.org/r/ee2caf4c138cc1fd239822c2abefd5af6c057744.1615559068.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agokasan: docs: update SW_TAGS implementation details section
Andrey Konovalov [Fri, 30 Apr 2021 06:00:30 +0000 (23:00 -0700)]
kasan: docs: update SW_TAGS implementation details section

Update the "Implementation details" section for SW_TAGS KASAN:

 - Clarify the introduction sentence.

 - Punctuation, readability, and other minor clean-ups.

Link: https://lkml.kernel.org/r/69b9b2e49d8cf789358fa24558be3fc0ce4ee32c.1615559068.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agokasan: docs: update GENERIC implementation details section
Andrey Konovalov [Fri, 30 Apr 2021 06:00:27 +0000 (23:00 -0700)]
kasan: docs: update GENERIC implementation details section

Update the "Implementation details" section for generic KASAN:

 - Don't mention kmemcheck, it's not present in the kernel anymore.

 - Don't mention GCC as the only supported compiler.

 - Update kasan_mem_to_shadow() definition to match actual code.

 - Punctuation, readability, and other minor clean-ups.

Link: https://lkml.kernel.org/r/f2f35fdab701f8c709f63d328f98aec2982c8acc.1615559068.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agokasan: docs: update boot parameters section
Andrey Konovalov [Fri, 30 Apr 2021 06:00:24 +0000 (23:00 -0700)]
kasan: docs: update boot parameters section

Update the "Boot parameters" section in KASAN documentation:

 - Mention panic_on_warn.

 - Mention kasan_multi_shot and its interaction with panic_on_warn.

 - Clarify kasan.fault=panic interaction with panic_on_warn.

 - A readability clean-up.

Link: https://lkml.kernel.org/r/01364952f15789948f0627d6733b5cdf5209f83a.1615559068.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agokasan: docs: update error reports section
Andrey Konovalov [Fri, 30 Apr 2021 06:00:21 +0000 (23:00 -0700)]
kasan: docs: update error reports section

Update the "Error reports" section in KASAN documentation:

 - Mention that bug titles are best-effort.

 - Move and reword the part about auxiliary stacks from "Implementation
   details".

 - Punctuation, readability, and other minor clean-ups.

Link: https://lkml.kernel.org/r/3531e8fe6972cf39d1954e3643237b19eb21227e.1615559068.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agokasan: docs: update usage section
Andrey Konovalov [Fri, 30 Apr 2021 06:00:18 +0000 (23:00 -0700)]
kasan: docs: update usage section

Update the "Usage" section in KASAN documentation:

 - Add inline code snippet markers.

 - Reword the part about stack traces for clarity.

 - Other minor clean-ups.

Link: https://lkml.kernel.org/r/48427809cd4b8b5d6bc00926cbe87e2b5081df17.1615559068.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agokasan: docs: update overview section
Andrey Konovalov [Fri, 30 Apr 2021 06:00:15 +0000 (23:00 -0700)]
kasan: docs: update overview section

Update the "Overview" section in KASAN documentation:

 - Outline main use cases for each mode.

 - Mention that HW_TAGS mode need compiler support too.

 - Move the part about SLUB/SLAB support from "Usage" to "Overview".

 - Punctuation, readability, and other minor clean-ups.

Link: https://lkml.kernel.org/r/1486fba8514de3d7db2f47df2192db59228b0a7b.1615559068.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agokasan: docs: clean up sections
Andrey Konovalov [Fri, 30 Apr 2021 06:00:12 +0000 (23:00 -0700)]
kasan: docs: clean up sections

Update KASAN documentation:

 - Give some sections clearer names.

 - Remove unneeded subsections in the "Tests" section.

 - Move the "For developers" section and split into subsections.

Link: https://lkml.kernel.org/r/c2bbb56eaea80ad484f0ee85bb71959a3a63f1d7.1615559068.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agokasan, mm: integrate slab init_on_free with HW_TAGS
Andrey Konovalov [Fri, 30 Apr 2021 06:00:09 +0000 (23:00 -0700)]
kasan, mm: integrate slab init_on_free with HW_TAGS

This change uses the previously added memory initialization feature of
HW_TAGS KASAN routines for slab memory when init_on_free is enabled.

With this change, memory initialization memset() is no longer called when
both HW_TAGS KASAN and init_on_free are enabled.  Instead, memory is
initialized in KASAN runtime.

For SLUB, the memory initialization memset() is moved into
slab_free_hook() that currently directly follows the initialization loop.
A new argument is added to slab_free_hook() that indicates whether to
initialize the memory or not.

To avoid discrepancies with which memory gets initialized that can be
caused by future changes, both KASAN hook and initialization memset() are
put together and a warning comment is added.

Combining setting allocation tags with memory initialization improves
HW_TAGS KASAN performance when init_on_free is enabled.

Link: https://lkml.kernel.org/r/190fd15c1886654afdec0d19ebebd5ade665b601.1615296150.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.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: Evgenii Stepanov <eugenis@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agokasan, mm: integrate slab init_on_alloc with HW_TAGS
Andrey Konovalov [Fri, 30 Apr 2021 06:00:06 +0000 (23:00 -0700)]
kasan, mm: integrate slab init_on_alloc with HW_TAGS

This change uses the previously added memory initialization feature of
HW_TAGS KASAN routines for slab memory when init_on_alloc is enabled.

With this change, memory initialization memset() is no longer called when
both HW_TAGS KASAN and init_on_alloc are enabled.  Instead, memory is
initialized in KASAN runtime.

The memory initialization memset() is moved into slab_post_alloc_hook()
that currently directly follows the initialization loop.  A new argument
is added to slab_post_alloc_hook() that indicates whether to initialize
the memory or not.

To avoid discrepancies with which memory gets initialized that can be
caused by future changes, both KASAN hook and initialization memset() are
put together and a warning comment is added.

Combining setting allocation tags with memory initialization improves
HW_TAGS KASAN performance when init_on_alloc is enabled.

Link: https://lkml.kernel.org/r/c1292aeb5d519da221ec74a0684a949b027d7720.1615296150.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.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: Evgenii Stepanov <eugenis@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agokasan, mm: integrate page_alloc init with HW_TAGS
Andrey Konovalov [Fri, 30 Apr 2021 06:00:02 +0000 (23:00 -0700)]
kasan, mm: integrate page_alloc init with HW_TAGS

This change uses the previously added memory initialization feature of
HW_TAGS KASAN routines for page_alloc memory when init_on_alloc/free is
enabled.

With this change, kernel_init_free_pages() is no longer called when both
HW_TAGS KASAN and init_on_alloc/free are enabled.  Instead, memory is
initialized in KASAN runtime.

To avoid discrepancies with which memory gets initialized that can be
caused by future changes, both KASAN and kernel_init_free_pages() hooks
are put together and a warning comment is added.

This patch changes the order in which memory initialization and page
poisoning hooks are called.  This doesn't lead to any side-effects, as
whenever page poisoning is enabled, memory initialization gets disabled.

Combining setting allocation tags with memory initialization improves
HW_TAGS KASAN performance when init_on_alloc/free is enabled.

[andreyknvl@google.com: fix for "integrate page_alloc init with HW_TAGS"]
Link: https://lkml.kernel.org/r/65b6028dea2e9a6e8e2cb779b5115c09457363fc.1617122211.git.andreyknvl@google.com
Link: https://lkml.kernel.org/r/e77f0d5b1b20658ef0b8288625c74c2b3690e725.1615296150.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Tested-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Sergei Trofimovich <slyfox@gentoo.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.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: Evgenii Stepanov <eugenis@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agokasan: init memory in kasan_(un)poison for HW_TAGS
Andrey Konovalov [Fri, 30 Apr 2021 05:59:59 +0000 (22:59 -0700)]
kasan: init memory in kasan_(un)poison for HW_TAGS

This change adds an argument to kasan_poison() and kasan_unpoison() that
allows initializing memory along with setting the tags for HW_TAGS.

Combining setting allocation tags with memory initialization will improve
HW_TAGS KASAN performance when init_on_alloc/free is enabled.

This change doesn't integrate memory initialization with KASAN, this is
done is subsequent patches in this series.

Link: https://lkml.kernel.org/r/3054314039fa64510947e674180d675cab1b4c41.1615296150.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.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: Evgenii Stepanov <eugenis@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agoarm64: kasan: allow to init memory when setting tags
Andrey Konovalov [Fri, 30 Apr 2021 05:59:55 +0000 (22:59 -0700)]
arm64: kasan: allow to init memory when setting tags

Patch series "kasan: integrate with init_on_alloc/free", v3.

This patch series integrates HW_TAGS KASAN with init_on_alloc/free by
initializing memory via the same arm64 instruction that sets memory tags.

This is expected to improve HW_TAGS KASAN performance when
init_on_alloc/free is enabled.  The exact perfomance numbers are unknown
as MTE-enabled hardware doesn't exist yet.

This patch (of 5):

This change adds an argument to mte_set_mem_tag_range() that allows to
enable memory initialization when settinh the allocation tags.  The
implementation uses stzg instruction instead of stg when this argument
indicates to initialize memory.

Combining setting allocation tags with memory initialization will improve
HW_TAGS KASAN performance when init_on_alloc/free is enabled.

This change doesn't integrate memory initialization with KASAN, this is
done is subsequent patches in this series.

Link: https://lkml.kernel.org/r/cover.1615296150.git.andreyknvl@google.com
Link: https://lkml.kernel.org/r/d04ae90cc36be3fe246ea8025e5085495681c3d7.1615296150.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Marco Elver <elver@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm, kasan: don't poison boot memory with tag-based modes
Andrey Konovalov [Fri, 30 Apr 2021 05:59:52 +0000 (22:59 -0700)]
mm, kasan: don't poison boot memory with tag-based modes

During boot, all non-reserved memblock memory is exposed to page_alloc via
memblock_free_pages->__free_pages_core().  This results in
kasan_free_pages() being called, which poisons that memory.

Poisoning all that memory lengthens boot time.  The most noticeable effect
is observed with the HW_TAGS mode.  A boot-time impact may potentially
also affect systems with large amount of RAM.

This patch changes the tag-based modes to not poison the memory during the
memblock->page_alloc transition.

An exception is made for KASAN_GENERIC.  Since it marks all new memory as
accessible, not poisoning the memory released from memblock will lead to
KASAN missing invalid boot-time accesses to that memory.

With KASAN_SW_TAGS, as it uses the invalid 0xFE tag as the default tag for
all memory, it won't miss bad boot-time accesses even if the poisoning of
memblock memory is removed.

With KASAN_HW_TAGS, the default memory tags values are unspecified.
Therefore, if memblock poisoning is removed, this KASAN mode will miss the
mentioned type of boot-time bugs with a 1/16 probability.  This is taken
as an acceptable trafe-off.

Internally, the poisoning is removed as follows.  __free_pages_core() is
used when exposing fresh memory during system boot and when onlining
memory during hotplug.  This patch adds a new FPI_SKIP_KASAN_POISON flag
and passes it to __free_pages_ok() through free_pages_prepare() from
__free_pages_core().  If FPI_SKIP_KASAN_POISON is set, kasan_free_pages()
is not called.

All memory allocated normally when the boot is over keeps getting poisoned
as usual.

Link: https://lkml.kernel.org/r/a0570dc1e3a8f39a55aa343a1fc08cd5c2d4cad6.1613692950.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agokasan: initialize shadow to TAG_INVALID for SW_TAGS
Andrey Konovalov [Fri, 30 Apr 2021 05:59:49 +0000 (22:59 -0700)]
kasan: initialize shadow to TAG_INVALID for SW_TAGS

Currently, KASAN_SW_TAGS uses 0xFF as the default tag value for
unallocated memory.  The underlying idea is that since that memory hasn't
been allocated yet, it's only supposed to be dereferenced through a
pointer with the native 0xFF tag.

While this is a good idea in terms on consistency, practically it doesn't
bring any benefit.  Since the 0xFF pointer tag is a match-all tag, it
doesn't matter what tag the accessed memory has.  No accesses through
0xFF-tagged pointers are considered buggy by KASAN.

This patch changes the default tag value for unallocated memory to 0xFE,
which is the tag KASAN uses for inaccessible memory.  This doesn't affect
accesses through 0xFF-tagged pointer to this memory, but this allows KASAN
to detect wild and large out-of-bounds invalid memory accesses through
otherwise-tagged pointers.

This is a prepatory patch for the next one, which changes the tag-based
KASAN modes to not poison the boot memory.

Link: https://lkml.kernel.org/r/c8e93571c18b3528aac5eb33ade213bf133d10ad.1613692950.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agokasan: fix kasan_byte_accessible() to be consistent with actual checks
Peter Collingbourne [Fri, 30 Apr 2021 05:59:46 +0000 (22:59 -0700)]
kasan: fix kasan_byte_accessible() to be consistent with actual checks

We can sometimes end up with kasan_byte_accessible() being called on
non-slab memory.  For example ksize() and krealloc() may end up calling it
on KFENCE allocated memory.  In this case the memory will be tagged with
KASAN_SHADOW_INIT, which a subsequent patch ("kasan: initialize shadow to
TAG_INVALID for SW_TAGS") will set to the same value as KASAN_TAG_INVALID,
causing kasan_byte_accessible() to fail when called on non-slab memory.

This highlighted the fact that the check in kasan_byte_accessible() was
inconsistent with checks as implemented for loads and stores
(kasan_check_range() in SW tags mode and hardware-implemented checks in HW
tags mode).  kasan_check_range() does not have a check for
KASAN_TAG_INVALID, and instead has a comparison against
KASAN_SHADOW_START.  In HW tags mode, we do not have either, but we do set
TCR_EL1.TCMA which corresponds with the comparison against
KASAN_TAG_KERNEL.

Therefore, update kasan_byte_accessible() for both SW and HW tags modes to
correspond with the respective checks on loads and stores.

Link: https://linux-review.googlesource.com/id/Ic6d40803c57dcc6331bd97fbb9a60b0d38a65a36
Link: https://lkml.kernel.org/r/20210405220647.1965262-1-pcc@google.com
Signed-off-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/kasan: switch from strlcpy to strscpy
Zhiyuan Dai [Fri, 30 Apr 2021 05:59:43 +0000 (22:59 -0700)]
mm/kasan: switch from strlcpy to strscpy

strlcpy is marked as deprecated in Documentation/process/deprecated.rst,
and there is no functional difference when the caller expects truncation
(when not checking the return value).  strscpy is relatively better as it
also avoids scanning the whole source string.

Link: https://lkml.kernel.org/r/1613970647-23272-1-git-send-email-daizhiyuan@phytium.com.cn
Signed-off-by: Zhiyuan Dai <daizhiyuan@phytium.com.cn>
Acked-by: Alexander Potapenko <glider@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agopagewalk: prefix struct kernel-doc descriptions
Lukas Bulwahn [Fri, 30 Apr 2021 05:59:40 +0000 (22:59 -0700)]
pagewalk: prefix struct kernel-doc descriptions

The script './scripts/kernel-doc -none ./include/linux/pagewalk.h' reports:

  include/linux/pagewalk.h:37: warning: cannot understand function prototype: 'struct mm_walk_ops '
  include/linux/pagewalk.h:85: warning: cannot understand function prototype: 'struct mm_walk '

A kernel-doc description for a structure requires to prefix the struct
name with the keyword 'struct'.  So, do that such that no further
kernel-doc warnings are reported for this file.

Link: https://lkml.kernel.org/r/20210322122542.15072-3-lukas.bulwahn@gmail.com
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ralf Ramsauer <ralf.ramsauer@oth-regensburg.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agoMAINTAINERS: assign pagewalk.h to MEMORY MANAGEMENT
Lukas Bulwahn [Fri, 30 Apr 2021 05:59:37 +0000 (22:59 -0700)]
MAINTAINERS: assign pagewalk.h to MEMORY MANAGEMENT

Patch series "kernel-doc and MAINTAINERS clean-up".

Roughly 900 warnings of about 21.000 kernel-doc warnings in the kernel
tree warn with 'cannot understand function prototype:', i.e., the
kernel-doc parser cannot parse the function's signature.  The majority,
about 600 cases of those, are just struct definitions following the
kernel-doc description.  Further, spot-check investigations suggest that
the authors of the specific kernel-doc descriptions simply were not
aware that the general format for a kernel-doc description for a
structure requires to prefix the struct name with the keyword 'struct',
as in 'struct struct_name - Brief description.'.  Details on kernel-doc
are at the Link below.

Without the struct keyword, kernel-doc does not check if the kernel-doc
description fits to the actual struct definition in the source code.
Fortunately, in roughly a quarter of these cases, the kernel-doc
description is actually complete wrt.  its corresponding struct
definition.  So, the trivial change adding the struct keyword will allow
us to keep the kernel-doc descriptions more consistent for future
changes, by checking for new kernel-doc warnings.

Also, some of the files in ./include/ are not assigned to a specific
MAINTAINERS section and hence have no dedicated maintainer.  So, if
needed, the files in ./include/ are also assigned to the fitting
MAINTAINERS section, as I need to identify whom to send the clean-up
patch anyway.

Here is the change from this kernel-doc janitorial work in the
./include/ directory for MEMORY MANAGEMENT.

This patch (of 2):

Commit 7de01c5d6089 ("mm: split out a new pagewalk.h header from mm.h")
adds a new file in ./include/linux, but misses to update MAINTAINERS
accordingly.  Hence,

  ./scripts/get_maintainers.pl include/linux/pagewalk.h

points only to lkml as general fallback for all files, whereas the
original include/linux/mm.h clearly marks this file part of MEMORY
MANAGEMENT.

Assign include/linux/pagewalk.h to MEMORY MANAGEMENT.

Link: https://lkml.kernel.org/r/20210322122542.15072-1-lukas.bulwahn@gmail.com
Link: https://lkml.kernel.org/r/20210322122542.15072-2-lukas.bulwahn@gmail.com
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Ralf Ramsauer <ralf.ramsauer@oth-regensburg.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/doc: add mm.h and mm_types.h to the mm-api document
Matthew Wilcox (Oracle) [Fri, 30 Apr 2021 05:59:34 +0000 (22:59 -0700)]
mm/doc: add mm.h and mm_types.h to the mm-api document

kerneldoc in include/linux/mm.h and include/linux/mm_types.h wasn't being
included in the html build.

Link: https://lkml.kernel.org/r/20210322195022.2143603-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/doc: turn fault flags into an enum
Matthew Wilcox (Oracle) [Fri, 30 Apr 2021 05:59:31 +0000 (22:59 -0700)]
mm/doc: turn fault flags into an enum

The kernel-doc script complains about

  include/linux/mm.h:425: warning: wrong kernel-doc identifier on line:
   * Fault flag definitions.

I don't know how to document a series of #defines, so turn these
definitions into an enum and document that instead.

Link: https://lkml.kernel.org/r/20210322195022.2143603-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/doc: fix page_maybe_dma_pinned kerneldoc
Matthew Wilcox (Oracle) [Fri, 30 Apr 2021 05:59:28 +0000 (22:59 -0700)]
mm/doc: fix page_maybe_dma_pinned kerneldoc

make htmldocs reports:

  include/linux/mm.h:1341: warning: Excess function parameter 'Return' description in 'page_maybe_dma_pinned'

Fix a few other formatting nits while I'm editing this description.

Link: https://lkml.kernel.org/r/20210322195022.2143603-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/doc: fix fault_flag_allow_retry_first kerneldoc
Matthew Wilcox (Oracle) [Fri, 30 Apr 2021 05:59:25 +0000 (22:59 -0700)]
mm/doc: fix fault_flag_allow_retry_first kerneldoc

make htmldocs reports:

  include/linux/mm.h:496: warning: Function parameter or member 'flags' not described in 'fault_flag_allow_retry_first'

Add a description.

Link: https://lkml.kernel.org/r/20210322195022.2143603-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/vmalloc: remove an empty line
Uladzislau Rezki (Sony) [Fri, 30 Apr 2021 05:59:22 +0000 (22:59 -0700)]
mm/vmalloc: remove an empty line

Link: https://lkml.kernel.org/r/20210402202237.20334-5-urezki@gmail.com
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/vmalloc: refactor the preloading loagic
Uladzislau Rezki (Sony) [Fri, 30 Apr 2021 05:59:19 +0000 (22:59 -0700)]
mm/vmalloc: refactor the preloading loagic

Instead of keeping open-coded style, move the code related to preloading
into a separate function.  Therefore introduce the preload_this_cpu_lock()
routine that prelaods a current CPU with one extra vmap_area object.

There is no functional change as a result of this patch.

Link: https://lkml.kernel.org/r/20210402202237.20334-4-urezki@gmail.com
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agovm/test_vmalloc.sh: adapt for updated driver interface
Uladzislau Rezki (Sony) [Fri, 30 Apr 2021 05:59:16 +0000 (22:59 -0700)]
vm/test_vmalloc.sh: adapt for updated driver interface

A 'single_cpu_test' parameter is odd and it does not exist anymore.
Instead there was introduced a 'nr_threads' one.  If it is not set it
behaves as the former parameter.

That is why update a "stress mode" according to this change specifying
number of workers which are equal to number of CPUs.  Also update an
output of help message based on a new interface.

Link: https://lkml.kernel.org/r/20210402202237.20334-3-urezki@gmail.com
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agolib/test_vmalloc.c: add a new 'nr_threads' parameter
Uladzislau Rezki (Sony) [Fri, 30 Apr 2021 05:59:13 +0000 (22:59 -0700)]
lib/test_vmalloc.c: add a new 'nr_threads' parameter

By using this parameter we can specify how many workers are created to
perform vmalloc tests.  By default it is one CPU.  The maximum value is
set to 1024.

As a result of this change a 'single_cpu_test' one becomes obsolete,
therefore it is no longer needed.

[urezki@gmail.com: extend max value of nr_threads parameter]
Link: https://lkml.kernel.org/r/20210406124536.19658-1-urezki@gmail.com
Link: https://lkml.kernel.org/r/20210402202237.20334-2-urezki@gmail.com
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agolib/test_vmalloc.c: remove two kvfree_rcu() tests
Uladzislau Rezki (Sony) [Fri, 30 Apr 2021 05:59:10 +0000 (22:59 -0700)]
lib/test_vmalloc.c: remove two kvfree_rcu() tests

Remove two test cases related to kvfree_rcu() and SLAB.  Those are
considered as redundant now, because similar test functionality has
recently been introduced in the "rcuscale" RCU test-suite.

Link: https://lkml.kernel.org/r/20210402202237.20334-1-urezki@gmail.com
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm: vmalloc: prevent use after free in _vm_unmap_aliases
Vijayanand Jitta [Fri, 30 Apr 2021 05:59:07 +0000 (22:59 -0700)]
mm: vmalloc: prevent use after free in _vm_unmap_aliases

A potential use after free can occur in _vm_unmap_aliases where an already
freed vmap_area could be accessed, Consider the following scenario:

Process 1 Process 2

__vm_unmap_aliases __vm_unmap_aliases
purge_fragmented_blocks_allcpus rcu_read_lock()
rcu_read_lock()
list_del_rcu(&vb->free_list)
list_for_each_entry_rcu(vb .. )
__purge_vmap_area_lazy
kmem_cache_free(va)
va_start = vb->va->va_start

Here Process 1 is in purge path and it does list_del_rcu on vmap_block and
later frees the vmap_area, since Process 2 was holding the rcu lock at
this time vmap_block will still be present in and Process 2 accesse it and
thereby it tries to access vmap_area of that vmap_block which was already
freed by Process 1 and this results in use after free.

Fix this by adding a check for vb->dirty before accessing vmap_area
structure since vb->dirty will be set to VMAP_BBMAP_BITS in purge path
checking for this will prevent the use after free.

Link: https://lkml.kernel.org/r/1616062105-23263-1-git-send-email-vjitta@codeaurora.org
Signed-off-by: Vijayanand Jitta <vjitta@codeaurora.org>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/vmalloc: improve allocation failure error messages
Nicholas Piggin [Fri, 30 Apr 2021 05:59:04 +0000 (22:59 -0700)]
mm/vmalloc: improve allocation failure error messages

There are several reasons why a vmalloc can fail, virtual space exhausted,
page array allocation failure, page allocation failure, and kernel page
table allocation failure.

Add distinct warning messages for the main causes of failure, with some
added information like page order or allocation size where applicable.

[urezki@gmail.com: print correct vmalloc allocation size]
Link: https://lkml.kernel.org/r/20210329193214.GA28602@pc638.lan
Link: https://lkml.kernel.org/r/20210322021806.892164-6-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/vmalloc: remove unmap_kernel_range
Nicholas Piggin [Fri, 30 Apr 2021 05:59:01 +0000 (22:59 -0700)]
mm/vmalloc: remove unmap_kernel_range

This is a shim around vunmap_range, get rid of it.

Move the main API comment from the _noflush variant to the normal
variant, and make _noflush internal to mm/.

[npiggin@gmail.com: fix nommu builds and a comment bug per sfr]
Link: https://lkml.kernel.org/r/1617292598.m6g0knx24s.astroid@bobo.none
[akpm@linux-foundation.org: move vunmap_range_noflush() stub inside !CONFIG_MMU, not !CONFIG_NUMA]
[npiggin@gmail.com: fix nommu builds]
Link: https://lkml.kernel.org/r/1617292497.o1uhq5ipxp.astroid@bobo.none
Link: https://lkml.kernel.org/r/20210322021806.892164-5-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Cédric Le Goater <clg@kaod.org>
Cc: Uladzislau Rezki <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agopowerpc/xive: remove unnecessary unmap_kernel_range
Nicholas Piggin [Fri, 30 Apr 2021 05:58:58 +0000 (22:58 -0700)]
powerpc/xive: remove unnecessary unmap_kernel_range

iounmap will remove ptes.

Link: https://lkml.kernel.org/r/20210322021806.892164-4-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Cédric Le Goater <clg@kaod.org>
Cc: Uladzislau Rezki <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agokernel/dma: remove unnecessary unmap_kernel_range
Nicholas Piggin [Fri, 30 Apr 2021 05:58:55 +0000 (22:58 -0700)]
kernel/dma: remove unnecessary unmap_kernel_range

vunmap will remove ptes.

Link: https://lkml.kernel.org/r/20210322021806.892164-3-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Cédric Le Goater <clg@kaod.org>
Cc: Uladzislau Rezki <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/vmalloc: remove map_kernel_range
Nicholas Piggin [Fri, 30 Apr 2021 05:58:53 +0000 (22:58 -0700)]
mm/vmalloc: remove map_kernel_range

Patch series "mm/vmalloc: cleanup after hugepage series", v2.

Christoph pointed out some overdue cleanups required after the huge
vmalloc series, and I had another failure error message improvement as
well.

This patch (of 5):

This is a shim around vmap_pages_range, get rid of it.

Move the main API comment from the _noflush variant to the normal variant,
and make _noflush internal to mm/.

Link: https://lkml.kernel.org/r/20210322021806.892164-1-npiggin@gmail.com
Link: https://lkml.kernel.org/r/20210322021806.892164-2-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/vmalloc: hugepage vmalloc mappings
Nicholas Piggin [Fri, 30 Apr 2021 05:58:49 +0000 (22:58 -0700)]
mm/vmalloc: hugepage vmalloc mappings

Support huge page vmalloc mappings.  Config option HAVE_ARCH_HUGE_VMALLOC
enables support on architectures that define HAVE_ARCH_HUGE_VMAP and
supports PMD sized vmap mappings.

vmalloc will attempt to allocate PMD-sized pages if allocating PMD size or
larger, and fall back to small pages if that was unsuccessful.

Architectures must ensure that any arch specific vmalloc allocations that
require PAGE_SIZE mappings (e.g., module allocations vs strict module rwx)
use the VM_NOHUGE flag to inhibit larger mappings.

This can result in more internal fragmentation and memory overhead for a
given allocation, an option nohugevmalloc is added to disable at boot.

[colin.king@canonical.com: fix read of uninitialized pointer area]
Link: https://lkml.kernel.org/r/20210318155955.18220-1-colin.king@canonical.com
Link: https://lkml.kernel.org/r/20210317062402.533919-14-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ding Tianhong <dingtianhong@huawei.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/vmalloc: add vmap_range_noflush variant
Nicholas Piggin [Fri, 30 Apr 2021 05:58:46 +0000 (22:58 -0700)]
mm/vmalloc: add vmap_range_noflush variant

As a side-effect, the order of flush_cache_vmap() and
arch_sync_kernel_mappings() calls are switched, but that now matches the
other callers in this file.

Link: https://lkml.kernel.org/r/20210317062402.533919-13-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ding Tianhong <dingtianhong@huawei.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm: move vmap_range from mm/ioremap.c to mm/vmalloc.c
Nicholas Piggin [Fri, 30 Apr 2021 05:58:43 +0000 (22:58 -0700)]
mm: move vmap_range from mm/ioremap.c to mm/vmalloc.c

This is a generic kernel virtual memory mapper, not specific to ioremap.

Code is unchanged other than making vmap_range non-static.

Link: https://lkml.kernel.org/r/20210317062402.533919-12-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ding Tianhong <dingtianhong@huawei.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/vmalloc: provide fallback arch huge vmap support functions
Nicholas Piggin [Fri, 30 Apr 2021 05:58:39 +0000 (22:58 -0700)]
mm/vmalloc: provide fallback arch huge vmap support functions

If an architecture doesn't support a particular page table level as a huge
vmap page size then allow it to skip defining the support query function.

Link: https://lkml.kernel.org/r/20210317062402.533919-11-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Suggested-by: Christoph Hellwig <hch@lst.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ding Tianhong <dingtianhong@huawei.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agox86: inline huge vmap supported functions
Nicholas Piggin [Fri, 30 Apr 2021 05:58:36 +0000 (22:58 -0700)]
x86: inline huge vmap supported functions

This allows unsupported levels to be constant folded away, and so
p4d_free_pud_page can be removed because it's no longer linked to.

Link: https://lkml.kernel.org/r/20210317062402.533919-10-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ding Tianhong <dingtianhong@huawei.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agoarm64: inline huge vmap supported functions
Nicholas Piggin [Fri, 30 Apr 2021 05:58:33 +0000 (22:58 -0700)]
arm64: inline huge vmap supported functions

This allows unsupported levels to be constant folded away, and so
p4d_free_pud_page can be removed because it's no longer linked to.

Link: https://lkml.kernel.org/r/20210317062402.533919-9-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ding Tianhong <dingtianhong@huawei.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agopowerpc: inline huge vmap supported functions
Nicholas Piggin [Fri, 30 Apr 2021 05:58:30 +0000 (22:58 -0700)]
powerpc: inline huge vmap supported functions

This allows unsupported levels to be constant folded away, and so
p4d_free_pud_page can be removed because it's no longer linked to.

Link: https://lkml.kernel.org/r/20210317062402.533919-8-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ding Tianhong <dingtianhong@huawei.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm: HUGE_VMAP arch support cleanup
Nicholas Piggin [Fri, 30 Apr 2021 05:58:26 +0000 (22:58 -0700)]
mm: HUGE_VMAP arch support cleanup

This changes the awkward approach where architectures provide init
functions to determine which levels they can provide large mappings for,
to one where the arch is queried for each call.

This removes code and indirection, and allows constant-folding of dead
code for unsupported levels.

This also adds a prot argument to the arch query.  This is unused
currently but could help with some architectures (e.g., some powerpc
processors can't map uncacheable memory with large pages).

Link: https://lkml.kernel.org/r/20210317062402.533919-7-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Ding Tianhong <dingtianhong@huawei.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arm64]
Cc: Will Deacon <will@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/ioremap: rename ioremap_*_range to vmap_*_range
Nicholas Piggin [Fri, 30 Apr 2021 05:58:23 +0000 (22:58 -0700)]
mm/ioremap: rename ioremap_*_range to vmap_*_range

This will be used as a generic kernel virtual mapping function, so re-name
it in preparation.

Link: https://lkml.kernel.org/r/20210317062402.533919-6-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ding Tianhong <dingtianhong@huawei.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/vmalloc: rename vmap_*_range vmap_pages_*_range
Nicholas Piggin [Fri, 30 Apr 2021 05:58:19 +0000 (22:58 -0700)]
mm/vmalloc: rename vmap_*_range vmap_pages_*_range

The vmalloc mapper operates on a struct page * array rather than a linear
physical address, re-name it to make this distinction clear.

Link: https://lkml.kernel.org/r/20210317062402.533919-5-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ding Tianhong <dingtianhong@huawei.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm: apply_to_pte_range warn and fail if a large pte is encountered
Nicholas Piggin [Fri, 30 Apr 2021 05:58:16 +0000 (22:58 -0700)]
mm: apply_to_pte_range warn and fail if a large pte is encountered

apply_to_pte_range might mistake a large pte for bad, or treat it as a
page table, resulting in a crash or corruption.  Add a test to warn and
return error if large entries are found.

Link: https://lkml.kernel.org/r/20210317062402.533919-4-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ding Tianhong <dingtianhong@huawei.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agomm/vmalloc: fix HUGE_VMAP regression by enabling huge pages in vmalloc_to_page
Nicholas Piggin [Fri, 30 Apr 2021 05:58:13 +0000 (22:58 -0700)]
mm/vmalloc: fix HUGE_VMAP regression by enabling huge pages in vmalloc_to_page

vmalloc_to_page returns NULL for addresses mapped by larger pages[*].
Whether or not a vmap is huge depends on the architecture details,
alignments, boot options, etc., which the caller can not be expected to
know.  Therefore HUGE_VMAP is a regression for vmalloc_to_page.

This change teaches vmalloc_to_page about larger pages, and returns the
struct page that corresponds to the offset within the large page.  This
makes the API agnostic to mapping implementation details.

[*] As explained by commit 75e6da1859a5f ("mm/vmalloc.c: huge-vmap:
    fail gracefully on unexpected huge vmap mappings")

[npiggin@gmail.com: sparc32: add stub pud_page define for walking huge vmalloc page tables]
Link: https://lkml.kernel.org/r/20210324232825.1157363-1-npiggin@gmail.com
Link: https://lkml.kernel.org/r/20210317062402.533919-3-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ding Tianhong <dingtianhong@huawei.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Will Deacon <will@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3 years agoARM: mm: add missing pud_page define to 2-level page tables
Nicholas Piggin [Fri, 30 Apr 2021 05:58:10 +0000 (22:58 -0700)]
ARM: mm: add missing pud_page define to 2-level page tables

Patch series "huge vmalloc mappings", v13.

The kernel virtual mapping layer grew support for mapping memory with >
PAGE_SIZE ptes with commit a8ff1e199667 ("lib/ioremap.c: add huge I/O
map capability interfaces"), and implemented support for using those
huge page mappings with ioremap.

According to the submission, the use-case is mapping very large
non-volatile memory devices, which could be GB or TB:

  https://lore.kernel.org/lkml/1425404664-19675-1-git-send-email-toshi.kani@hp.com/

The benefit is said to be in the overhead of maintaining the mapping,
perhaps both in memory overhead and setup / teardown time.  Memory
overhead for the mapping with a 4kB page and 8 byte page table is 2GB
per TB of mapping, down to 4MB / TB with 2MB pages.

The same huge page vmap infrastructure can be quite easily adapted and
used for mapping vmalloc memory pages without more complexity for arch
or core vmap code.  However unlike ioremap, vmalloc page table overhead
is not a real problem, so the advantage to justify this is performance.

Several of the most structures in the kernel (e.g., vfs and network hash
tables) are allocated with vmalloc on NUMA machines, in order to
distribute access bandwidth over the machine.  Mapping these with larger
pages can improve TLB usage significantly, for example this reduces TLB
misses by nearly 30x on a `git diff` workload on a 2-node POWER9 (59,800
-> 2,100) and reduces CPU cycles by 0.54%, due to vfs hashes being
allocated with 2MB pages.

[ Other numbers?
  - The difference is even larger in a guest due to more costly TLB
    misses.
  - Eric Dumazet was keen on the network hash performance possibilities.
  - Other archs? Ding was doing x86 testing. ]

The kernel module allocator also uses vmalloc to map module images even on
non-NUMA, which can result in high iTLB pressure on highly modular distro
type of kernels.  This series does not implement huge mappings for modules
yet, but it's a step along the way.  Rick Edgecombe was looking at that
IIRC.

The per-cpu allocator similarly might be able to take advantage of this.
Also on the todo list.

The disadvantages of this I can see are:
* Memory fragmentation can waste some physical memory because it will
  attempt to allocate larger pages to fit the required size, rounding up
  (once the requested size is >= 2MB).
  - I don't see it being a big problem in practice unless some user
    crops up that allocates thousands of 2.5MB ranges. We can tewak
    heuristics a bit there if needed to reduce peak waste.
* Less granular mappings can make the NUMA distribution less balanced.
  - Similar to the above.
  - Could also allocate all major system hashes with one allocation
    up-front and spread them all across the one block, which should help
    overall NUMA distribution and reduce fragmentation waste.
* Callers might expect something about the underlying allocated pages.
  - Tried to keep the apperance of base PAGE_SIZE pages throughout the
    APIs and exposed data structures.
  - Added a VM_NO_HUGE_VMAP flag to hammer troublesome cases with.

- Finally, added a nohugevmalloc boot option to turn it off (independent
  of nohugeiomap).

This patch (of 14):

ARM uses its own PMD folding scheme which is missing pud_page which should
just pass through to pmd_page.  Move this from the 3-level page table to
common header.

Link: https://lkml.kernel.org/r/20210317062402.533919-2-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Ding Tianhong <dingtianhong@huawei.com>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>