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  1. 17 2月, 2019 1 次提交
    • M
      powerpc/64s: Fix possible corruption on big endian due to pgd/pud_present() · a5800762
      由 Michael Ellerman 提交于 
      In v4.20 we changed our pgd/pud_present() to check for _PAGE_PRESENT
rather than just checking that the value is non-zero, e.g.:

  static inline int pgd_present(pgd_t pgd)
  {
 -       return !pgd_none(pgd);
 +       return (pgd_raw(pgd) & cpu_to_be64(_PAGE_PRESENT));
  }

Unfortunately this is broken on big endian, as the result of the
bitwise & is truncated to int, which is always zero because
_PAGE_PRESENT is 0x8000000000000000ul. This means pgd_present() and
pud_present() are always false at compile time, and the compiler
elides the subsequent code.

Remarkably with that bug present we are still able to boot and run
with few noticeable effects. However under some work loads we are able
to trigger a warning in the ext4 code:

  WARNING: CPU: 11 PID: 29593 at fs/ext4/inode.c:3927 .ext4_set_page_dirty+0x70/0xb0
  CPU: 11 PID: 29593 Comm: debugedit Not tainted 4.20.0-rc1 #1
  ...
  NIP .ext4_set_page_dirty+0x70/0xb0
  LR  .set_page_dirty+0xa0/0x150
  Call Trace:
   .set_page_dirty+0xa0/0x150
   .unmap_page_range+0xbf0/0xe10
   .unmap_vmas+0x84/0x130
   .unmap_region+0xe8/0x190
   .__do_munmap+0x2f0/0x510
   .__vm_munmap+0x80/0x110
   .__se_sys_munmap+0x14/0x30
   system_call+0x5c/0x70

The fix is simple, we need to convert the result of the bitwise & to
an int before returning it.

Thanks to Erhard, Jan Kara and Aneesh for help with debugging.

Fixes: da7ad366 ("powerpc/mm/book3s: Update pmd_present to look at _PAGE_PRESENT bit")
Cc: stable@vger.kernel.org # v4.20+
Reported-by: NErhard F. <erhard_f@mailbox.org>
Reviewed-by: NAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      a5800762
  3. 31 1月, 2019 1 次提交
    • A
      powerpc/radix: Fix kernel crash with mremap() · 579b9239
      由 Aneesh Kumar K.V 提交于 
      With support for split pmd lock, we use pmd page pmd_huge_pte pointer
to store the deposited page table. In those config when we move page
tables we need to make sure we move the deposited page table to the
correct pmd page. Otherwise this can result in crash when we withdraw
of deposited page table because we can find the pmd_huge_pte NULL.

eg:

  __split_huge_pmd+0x1070/0x1940
  __split_huge_pmd+0xe34/0x1940 (unreliable)
  vma_adjust_trans_huge+0x110/0x1c0
  __vma_adjust+0x2b4/0x9b0
  __split_vma+0x1b8/0x280
  __do_munmap+0x13c/0x550
  sys_mremap+0x220/0x7e0
  system_call+0x5c/0x70

Fixes: 675d9952 ("powerpc/book3s64: Enable split pmd ptlock.")
Cc: stable@vger.kernel.org # v4.18+
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      579b9239
  5. 25 11月, 2018 1 次提交
  7. 27 10月, 2018 1 次提交
  9. 18 10月, 2018 1 次提交
  11. 14 10月, 2018 5 次提交
  13. 10 10月, 2018 1 次提交
    • J
      mm: Preserve _PAGE_DEVMAP across mprotect() calls · 4628a645
      由 Jan Kara 提交于 
      Currently _PAGE_DEVMAP bit is not preserved in mprotect(2) calls. As a
result we will see warnings such as:

BUG: Bad page map in process JobWrk0013  pte:800001803875ea25 pmd:7624381067
addr:00007f0930720000 vm_flags:280000f9 anon_vma:          (null) mapping:ffff97f2384056f0 index:0
file:457-000000fe00000030-00000009-000000ca-00000001_2001.fileblock fault:xfs_filemap_fault [xfs] mmap:xfs_file_mmap [xfs] readpage:          (null)
CPU: 3 PID: 15848 Comm: JobWrk0013 Tainted: G        W          4.12.14-2.g7573215-default #1 SLE12-SP4 (unreleased)
Hardware name: Intel Corporation S2600WFD/S2600WFD, BIOS SE5C620.86B.01.00.0833.051120182255 05/11/2018
Call Trace:
 dump_stack+0x5a/0x75
 print_bad_pte+0x217/0x2c0
 ? enqueue_task_fair+0x76/0x9f0
 _vm_normal_page+0xe5/0x100
 zap_pte_range+0x148/0x740
 unmap_page_range+0x39a/0x4b0
 unmap_vmas+0x42/0x90
 unmap_region+0x99/0xf0
 ? vma_gap_callbacks_rotate+0x1a/0x20
 do_munmap+0x255/0x3a0
 vm_munmap+0x54/0x80
 SyS_munmap+0x1d/0x30
 do_syscall_64+0x74/0x150
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
...

when mprotect(2) gets used on DAX mappings. Also there is a wide variety
of other failures that can result from the missing _PAGE_DEVMAP flag
when the area gets used by get_user_pages() later.

Fix the problem by including _PAGE_DEVMAP in a set of flags that get
preserved by mprotect(2).

Fixes: 69660fd7 ("x86, mm: introduce _PAGE_DEVMAP")
Fixes: ebd31197 ("powerpc/mm: Add devmap support for ppc64")
Cc: <stable@vger.kernel.org>
Signed-off-by: NJan Kara <jack@suse.cz>
Acked-by: NMichal Hocko <mhocko@suse.com>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
      4628a645
  15. 03 10月, 2018 3 次提交
  17. 30 9月, 2018 1 次提交
    • M
      xarray: Replace exceptional entries · 3159f943
      由 Matthew Wilcox 提交于 
      Introduce xarray value entries and tagged pointers to replace radix
tree exceptional entries.  This is a slight change in encoding to allow
the use of an extra bit (we can now store BITS_PER_LONG - 1 bits in a
value entry).  It is also a change in emphasis; exceptional entries are
intimidating and different.  As the comment explains, you can choose
to store values or pointers in the xarray and they are both first-class
citizens.
Signed-off-by: NMatthew Wilcox <willy@infradead.org>
Reviewed-by: NJosef Bacik <jbacik@fb.com>
      3159f943
  19. 12 9月, 2018 1 次提交
    • A
      KVM: PPC: Avoid marking DMA-mapped pages dirty in real mode · 425333bf
      由 Alexey Kardashevskiy 提交于 
      At the moment the real mode handler of H_PUT_TCE calls iommu_tce_xchg_rm()
which in turn reads the old TCE and if it was a valid entry, marks
the physical page dirty if it was mapped for writing. Since it is in
real mode, realmode_pfn_to_page() is used instead of pfn_to_page()
to get the page struct. However SetPageDirty() itself reads the compound
page head and returns a virtual address for the head page struct and
setting dirty bit for that kills the system.

This adds additional dirty bit tracking into the MM/IOMMU API for use
in the real mode. Note that this does not change how VFIO and
KVM (in virtual mode) set this bit. The KVM (real mode) changes include:
- use the lowest bit of the cached host phys address to carry
the dirty bit;
- mark pages dirty when they are unpinned which happens when
the preregistered memory is released which always happens in virtual
mode;
- add mm_iommu_ua_mark_dirty_rm() helper to set delayed dirty bit;
- change iommu_tce_xchg_rm() to take the kvm struct for the mm to use
in the new mm_iommu_ua_mark_dirty_rm() helper;
- move iommu_tce_xchg_rm() to book3s_64_vio_hv.c (which is the only
caller anyway) to reduce the real mode KVM and IOMMU knowledge
across different subsystems.

This removes realmode_pfn_to_page() as it is not used anymore.

While we at it, remove some EXPORT_SYMBOL_GPL() as that code is for
the real mode only and modules cannot call it anyway.
Signed-off-by: NAlexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NPaul Mackerras <paulus@ozlabs.org>
      425333bf
  21. 23 8月, 2018 1 次提交
  23. 16 7月, 2018 1 次提交
  25. 20 6月, 2018 1 次提交
  27. 08 6月, 2018 1 次提交
    • L
      mm: introduce ARCH_HAS_PTE_SPECIAL · 3010a5ea
      由 Laurent Dufour 提交于 
      Currently the PTE special supports is turned on in per architecture
header files.  Most of the time, it is defined in
arch/*/include/asm/pgtable.h depending or not on some other per
architecture static definition.

This patch introduce a new configuration variable to manage this
directly in the Kconfig files.  It would later replace
__HAVE_ARCH_PTE_SPECIAL.

Here notes for some architecture where the definition of
__HAVE_ARCH_PTE_SPECIAL is not obvious:

arm
 __HAVE_ARCH_PTE_SPECIAL which is currently defined in
arch/arm/include/asm/pgtable-3level.h which is included by
arch/arm/include/asm/pgtable.h when CONFIG_ARM_LPAE is set.
So select ARCH_HAS_PTE_SPECIAL if ARM_LPAE.

powerpc
__HAVE_ARCH_PTE_SPECIAL is defined in 2 files:
 - arch/powerpc/include/asm/book3s/64/pgtable.h
 - arch/powerpc/include/asm/pte-common.h
The first one is included if (PPC_BOOK3S & PPC64) while the second is
included in all the other cases.
So select ARCH_HAS_PTE_SPECIAL all the time.

sparc:
__HAVE_ARCH_PTE_SPECIAL is defined if defined(__sparc__) &&
defined(__arch64__) which are defined through the compiler in
sparc/Makefile if !SPARC32 which I assume to be if SPARC64.
So select ARCH_HAS_PTE_SPECIAL if SPARC64

There is no functional change introduced by this patch.

Link: http://lkml.kernel.org/r/1523433816-14460-2-git-send-email-ldufour@linux.vnet.ibm.comSigned-off-by: NLaurent Dufour <ldufour@linux.vnet.ibm.com>
Suggested-by: NJerome Glisse <jglisse@redhat.com>
Reviewed-by: NJerome Glisse <jglisse@redhat.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Albert Ou <albert@sifive.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Christophe LEROY <christophe.leroy@c-s.fr>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      3010a5ea
  29. 03 6月, 2018 1 次提交
  31. 15 5月, 2018 3 次提交
  33. 30 3月, 2018 1 次提交
  35. 13 2月, 2018 2 次提交
  37. 01 2月, 2018 2 次提交
  39. 20 1月, 2018 3 次提交
  41. 16 1月, 2018 2 次提交
    • C
      powerpc/mm: Introduce _PAGE_NA · 35175033
      由 Christophe Leroy 提交于 
      Today, PAGE_NONE is defined as a page not having _PAGE_USER.
In some circunstances, when the CPU supports it, it might be
better to be able to flag a page with NO ACCESS.

In a following patch, the 8xx will switch user access being flagged
in the PMD, therefore it will not be possible anymore to use
_PAGE_USER as a way to flag a page with no access.
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      35175033
    • C
      powerpc/mm: extend _PAGE_PRIVILEGED to all CPUs · 812fadcb
      由 Christophe Leroy 提交于 
      commit ac29c640 ("powerpc/mm: Replace _PAGE_USER with
_PAGE_PRIVILEGED") introduced _PAGE_PRIVILEGED for BOOK3S/64

This patch generalises _PAGE_PRIVILEGED for all CPUs, allowing
to have either _PAGE_PRIVILEGED or _PAGE_USER or both.

PPC_8xx has a _PAGE_SHARED flag which is set for and only for
all non user pages. Lets rename it _PAGE_PRIVILEGED to remove
confusion as it has nothing to do with Linux shared pages.

On BookE, there's a _PAGE_BAP_SR which has to be set for kernel
pages: defining _PAGE_PRIVILEGED as _PAGE_BAP_SR will make
this generic
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      812fadcb
  43. 22 12月, 2017 1 次提交
  45. 30 11月, 2017 1 次提交
  47. 02 11月, 2017 1 次提交
    • G
      License cleanup: add SPDX GPL-2.0 license identifier to files with no license · b2441318
      由 Greg Kroah-Hartman 提交于 
      Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: NKate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: NPhilippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b2441318
  49. 17 8月, 2017 1 次提交
    • A
      powerpc/mm: Don't send IPI to all cpus on THP updates · fa4531f7
      由 Aneesh Kumar K.V 提交于 
      Now that we made sure that lockless walk of linux page table is mostly
limitted to current task(current->mm->pgdir) we can update the THP
update sequence to only send IPI to CPUs on which this task has run.
This helps in reducing the IPI overload on systems with large number
of CPUs.

WRT kvm even though kvm is walking page table with vpc->arch.pgdir,
it is done only on secondary CPUs and in that case we have primary CPU
added to task's mm cpumask. Sending an IPI to primary will force the
secondary to do a vm exit and hence this mm cpumask usage is safe
here.

WRT CAPI, we still end up walking linux page table with capi context
MM. For now the pte lookup serialization sends an IPI to all CPUs in
CPI is in use. We can further improve this by adding the CAPI
interrupt handling CPU to task mm cpumask. That will be done in a
later patch.
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      fa4531f7
  51. 15 8月, 2017 1 次提交
    • C
      powerpc/hugetlb: fix page rights verification in gup_hugepte() · ca8afd40
      由 Christophe Leroy 提交于 
      gup_hugepte() checks if pages are present and readable, and
when  'write' is set, also checks if the pages are writable.

Initially this was done by checking if _PAGE_PRESENT and
_PAGE_READ were set. In addition, _PAGE_WRITE was verified for write
accesses.

The problem is that we have to handle the three following cases:
1/ The target defines __PAGE_READ and __PAGE_WRITE
2/ The target defines __PAGE_RW
3/ The target defines __PAGE_RO

In case 1/, this is obvious
In case 2/, __PAGE_READ is defined as 0 and __PAGE_WRITE as __PAGE_RW
so it works as well.
But in case 3, __PAGE_RW is defined as 0, which means __PAGE_WRITE is 0
and then the test returns true (page writable) in all cases.

A first correction was attempted in commit 6b8cb66a ("powerpc: Fix
usage of _PAGE_RO in hugepage"), but that fix is wrong:
instead of checking that the page is writable when write is requested,
it checks that the page is NOT writable when write is NOT requested.

This patch adds a new pte_read() helper to check whether a page is
readable or not. This avoids handling all possible cases in
gup_hugepte().

Then gup_hugepte() is modified to use pte_present(), pte_read()
and pte_write() instead of the raw flags.
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      ca8afd40
  53. 08 8月, 2017 1 次提交