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  1. 12 3月, 2020 1 次提交
  3. 04 2月, 2020 2 次提交
  5. 30 1月, 2020 1 次提交
  7. 13 12月, 2019 1 次提交
  9. 12 12月, 2019 1 次提交
  11. 08 12月, 2019 1 次提交
  13. 01 12月, 2019 1 次提交
  15. 30 11月, 2019 2 次提交
    • M
      s390/livepatch: Implement reliable stack tracing for the consistency model · aa137a6d
      由 Miroslav Benes 提交于 
      The livepatch consistency model requires reliable stack tracing
architecture support in order to work properly. In order to achieve
this, two main issues have to be solved. First, reliable and consistent
call chain backtracing has to be ensured. Second, the unwinder needs to
be able to detect stack corruptions and return errors.

The "zSeries ELF Application Binary Interface Supplement" says:

  "The stack pointer points to the first word of the lowest allocated
  stack frame. If the "back chain" is implemented this word will point to
  the previously allocated stack frame (towards higher addresses), except
  for the first stack frame, which shall have a back chain of zero (NULL).
  The stack shall grow downwards, in other words towards lower addresses."

"back chain" is optional. GCC option -mbackchain enables it. Quoting
Martin Schwidefsky [1]:

  "The compiler is called with the -mbackchain option, all normal C
  function will store the backchain in the function prologue. All
  functions written in assembler code should do the same, if you find one
  that does not we should fix that. The end result is that a task that
  *voluntarily* called schedule() should have a proper backchain at all
  times.

  Dependent on the use case this may or may not be enough. Asynchronous
  interrupts may stop the CPU at the beginning of a function, if kernel
  preemption is enabled we can end up with a broken backchain.  The
  production kernels for IBM Z are all compiled *without* kernel
  preemption. So yes, we might get away without the objtool support.

  On a side-note, we do have a line item to implement the ORC unwinder for
  the kernel, that includes the objtool support. Once we have that we can
  drop the -mbackchain option for the kernel build. That gives us a nice
  little performance benefit. I hope that the change from backchain to the
  ORC unwinder will not be too hard to implement in the livepatch tools."

Since -mbackchain is enabled by default when the kernel is compiled, the
call chain backtracing should be currently ensured and objtool should
not be necessary for livepatch purposes.

Regarding the second issue, stack corruptions and non-reliable states
have to be recognized by the unwinder. Mainly it means to detect
preemption or page faults, the end of the task stack must be reached,
return addresses must be valid text addresses and hacks like function
graph tracing and kretprobes must be properly detected.

Unwinding a running task's stack is not a problem, because there is a
livepatch requirement that every checked task is blocked, except for the
current task. Due to that, the implementation can be much simpler
compared to the existing non-reliable infrastructure. We can consider a
task's kernel/thread stack only and skip the other stacks.

[1] 20180912121106.31ffa97c@mschwideX1 [not archived on lore.kernel.org]

Link: https://lkml.kernel.org/r/20191106095601.29986-5-mbenes@suse.czReviewed-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Tested-by: NMiroslav Benes <mbenes@suse.cz>
Signed-off-by: NMiroslav Benes <mbenes@suse.cz>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>
      aa137a6d
    • I
      s390/unwind: add a test for the internal API · badbf397
      由 Ilya Leoshkevich 提交于 
      unwind_for_each_frame can take at least 8 different sets of parameters.
Add a test to make sure they all are handled in a sane way.
Reviewed-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NIlya Leoshkevich <iii@linux.ibm.com>
Co-developed-by: NVasily Gorbik <gor@linux.ibm.com>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>
      badbf397
  17. 10 10月, 2019 2 次提交
  19. 13 9月, 2019 1 次提交
  21. 22 8月, 2019 1 次提交
  23. 21 8月, 2019 1 次提交
  25. 20 8月, 2019 1 次提交
  27. 09 8月, 2019 1 次提交
  29. 06 8月, 2019 1 次提交
  31. 17 7月, 2019 1 次提交
    • T
      dma-direct: Force unencrypted DMA under SME for certain DMA masks · 9087c375
      由 Tom Lendacky 提交于 
      If a device doesn't support DMA to a physical address that includes the
encryption bit (currently bit 47, so 48-bit DMA), then the DMA must
occur to unencrypted memory. SWIOTLB is used to satisfy that requirement
if an IOMMU is not active (enabled or configured in passthrough mode).

However, commit fafadcd1 ("swiotlb: don't dip into swiotlb pool for
coherent allocations") modified the coherent allocation support in
SWIOTLB to use the DMA direct coherent allocation support. When an IOMMU
is not active, this resulted in dma_alloc_coherent() failing for devices
that didn't support DMA addresses that included the encryption bit.

Addressing this requires changes to the force_dma_unencrypted() function
in kernel/dma/direct.c. Since the function is now non-trivial and
SME/SEV specific, update the DMA direct support to add an arch override
for the force_dma_unencrypted() function. The arch override is selected
when CONFIG_AMD_MEM_ENCRYPT is set. The arch override function resides in
the arch/x86/mm/mem_encrypt.c file and forces unencrypted DMA when either
SEV is active or SME is active and the device does not support DMA to
physical addresses that include the encryption bit.

Fixes: fafadcd1 ("swiotlb: don't dip into swiotlb pool for coherent allocations")
Suggested-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NTom Lendacky <thomas.lendacky@amd.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
[hch: moved the force_dma_unencrypted declaration to dma-mapping.h,
      fold the s390 fix from Halil Pasic]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
      9087c375
  33. 13 7月, 2019 2 次提交
  35. 15 6月, 2019 2 次提交
  37. 11 6月, 2019 1 次提交
    • M
      docs: s390: convert docs to ReST and rename to *.rst · 8b4a503d
      由 Mauro Carvalho Chehab 提交于 
      Convert all text files with s390 documentation to ReST format.

Tried to preserve as much as possible the original document
format. Still, some of the files required some work in order
for it to be visible on both plain text and after converted
to html.

The conversion is actually:
  - add blank lines and identation in order to identify paragraphs;
  - fix tables markups;
  - add some lists markups;
  - mark literal blocks;
  - adjust title markups.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
      8b4a503d
  39. 07 6月, 2019 2 次提交
  41. 04 6月, 2019 1 次提交
  43. 15 5月, 2019 3 次提交
    • M
      mm: memblock: make keeping memblock memory opt-in rather than opt-out · 350e88ba
      由 Mike Rapoport 提交于 
      Most architectures do not need the memblock memory after the page
allocator is initialized, but only few enable ARCH_DISCARD_MEMBLOCK in the
arch Kconfig.

Replacing ARCH_DISCARD_MEMBLOCK with ARCH_KEEP_MEMBLOCK and inverting the
logic makes it clear which architectures actually use memblock after
system initialization and skips the necessity to add ARCH_DISCARD_MEMBLOCK
to the architectures that are still missing that option.

Link: http://lkml.kernel.org/r/1556102150-32517-1-git-send-email-rppt@linux.ibm.comSigned-off-by: NMike Rapoport <rppt@linux.ibm.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.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: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      350e88ba
    • A
      hugetlb: allow to free gigantic pages regardless of the configuration · 4eb0716e
      由 Alexandre Ghiti 提交于 
      On systems without CONTIG_ALLOC activated but that support gigantic pages,
boottime reserved gigantic pages can not be freed at all.  This patch
simply enables the possibility to hand back those pages to memory
allocator.

Link: http://lkml.kernel.org/r/20190327063626.18421-5-alex@ghiti.frSigned-off-by: NAlexandre Ghiti <alex@ghiti.fr>
Acked-by: David S. Miller <davem@davemloft.net> [sparc]
Reviewed-by: NMike Kravetz <mike.kravetz@oracle.com>
Cc: Andy Lutomirsky <luto@kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      4eb0716e
    • A
      mm: simplify MEMORY_ISOLATION && COMPACTION || CMA into CONTIG_ALLOC · 8df995f6
      由 Alexandre Ghiti 提交于 
      This condition allows to define alloc_contig_range, so simplify it into a
more accurate naming.

Link: http://lkml.kernel.org/r/20190327063626.18421-4-alex@ghiti.frSigned-off-by: NAlexandre Ghiti <alex@ghiti.fr>
Suggested-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Andy Lutomirsky <luto@kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      8df995f6
  45. 03 5月, 2019 2 次提交
  47. 29 4月, 2019 3 次提交
  49. 23 4月, 2019 1 次提交
  51. 11 4月, 2019 1 次提交
  53. 10 4月, 2019 1 次提交
  55. 03 4月, 2019 2 次提交
    • W
      locking/rwsem: Remove rwsem-spinlock.c & use rwsem-xadd.c for all archs · 390a0c62
      由 Waiman Long 提交于 
      Currently, we have two different implementation of rwsem:

 1) CONFIG_RWSEM_GENERIC_SPINLOCK (rwsem-spinlock.c)
 2) CONFIG_RWSEM_XCHGADD_ALGORITHM (rwsem-xadd.c)

As we are going to use a single generic implementation for rwsem-xadd.c
and no architecture-specific code will be needed, there is no point
in keeping two different implementations of rwsem. In most cases, the
performance of rwsem-spinlock.c will be worse. It also doesn't get all
the performance tuning and optimizations that had been implemented in
rwsem-xadd.c over the years.

For simplication, we are going to remove rwsem-spinlock.c and make all
architectures use a single implementation of rwsem - rwsem-xadd.c.

All references to RWSEM_GENERIC_SPINLOCK and RWSEM_XCHGADD_ALGORITHM
in the code are removed.
Suggested-by: NPeter Zijlstra <peterz@infradead.org>
Signed-off-by: NWaiman Long <longman@redhat.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-c6x-dev@linux-c6x.org
Cc: linux-m68k@lists.linux-m68k.org
Cc: linux-riscv@lists.infradead.org
Cc: linux-um@lists.infradead.org
Cc: linux-xtensa@linux-xtensa.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: nios2-dev@lists.rocketboards.org
Cc: openrisc@lists.librecores.org
Cc: uclinux-h8-devel@lists.sourceforge.jp
Link: https://lkml.kernel.org/r/20190322143008.21313-3-longman@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      390a0c62
    • M
      s390/tlb: Convert to generic mmu_gather · 9de7d833
      由 Martin Schwidefsky 提交于 
      No change in behavior intended.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: aneesh.kumar@linux.vnet.ibm.com
Cc: heiko.carstens@de.ibm.com
Cc: linux@armlinux.org.uk
Cc: npiggin@gmail.com
Cc: will.deacon@arm.com
Link: http://lkml.kernel.org/r/20180918125151.31744-3-schwidefsky@de.ibm.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      9de7d833