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* [PATCH v5 00/14] Provide generic top-down mmap layout functions
@ 2019-07-30  5:50 ` Alexandre Ghiti
  0 siblings, 0 replies; 55+ messages in thread
From: Alexandre Ghiti @ 2019-07-30  5:50 UTC (permalink / raw)
  To: Andrew Morton
  Cc: Luis Chamberlain, Christoph Hellwig, Russell King,
	Catalin Marinas, Will Deacon, Ralf Baechle, Paul Burton,
	James Hogan, Palmer Dabbelt, Albert Ou, Alexander Viro,
	Kees Cook, linux-kernel, linux-arm-kernel, linux-mips,
	linux-riscv, linux-fsdevel, linux-mm, Alexandre Ghiti

This series introduces generic functions to make top-down mmap layout
easily accessible to architectures, in particular riscv which was
the initial goal of this series.
The generic implementation was taken from arm64 and used successively
by arm, mips and finally riscv.

Note that in addition the series fixes 2 issues:
- stack randomization was taken into account even if not necessary.
- [1] fixed an issue with mmap base which did not take into account
  randomization but did not report it to arm and mips, so by moving
  arm64 into a generic library, this problem is now fixed for both
  architectures.

This work is an effort to factorize architecture functions to avoid
code duplication and oversights as in [1].

[1]: https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1429066.html

Changes in v5:
  - Fix [PATCH 11/14]
  - Rebase on top of v5.3rc2 and commit
    "riscv: kbuild: add virtual memory system selection"
  - [PATCH 14/14] now takes into account the various virtual memory systems

Changes in v4:
  - Make ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT select ARCH_HAS_ELF_RANDOMIZE
    by default as suggested by Kees,
  - ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT depends on MMU and defines the
    functions needed by ARCH_HAS_ELF_RANDOMIZE => architectures that use
    the generic mmap topdown functions cannot have ARCH_HAS_ELF_RANDOMIZE
    selected without MMU, but I think it's ok since randomization without
    MMU does not add much security anyway.
  - There is no common API to determine if a process is 32b, so I came up with
    !IS_ENABLED(CONFIG_64BIT) || is_compat_task() in [PATCH v4 12/14].
  - Mention in the change log that x86 already takes care of not offseting mmap
    base address if the task does not want randomization.
  - Re-introduce a comment that should not have been removed.
  - Add Reviewed/Acked-By from Paul, Christoph and Kees, thank you for that.
  - I tried to minimize the changes from the commits in v3 in order to make
    easier the review of the v4, the commits changed or added are:
    - [PATCH v4 5/14]
    - [PATCH v4 8/14]
    - [PATCH v4 11/14]
    - [PATCH v4 12/14]
    - [PATCH v4 13/14]

Changes in v3:
  - Split into small patches to ease review as suggested by Christoph
    Hellwig and Kees Cook
  - Move help text of new config as a comment, as suggested by Christoph
  - Make new config depend on MMU, as suggested by Christoph

Changes in v2 as suggested by Christoph Hellwig:
  - Preparatory patch that moves randomize_stack_top
  - Fix duplicate config in riscv
  - Align #if defined on next line => this gives rise to a checkpatch
    warning. I found this pattern all around the tree, in the same proportion
    as the previous pattern which was less pretty:
    git grep -C 1 -n -P "^#if defined.+\|\|.*\\\\$"

Alexandre Ghiti (14):
  mm, fs: Move randomize_stack_top from fs to mm
  arm64: Make use of is_compat_task instead of hardcoding this test
  arm64: Consider stack randomization for mmap base only when necessary
  arm64, mm: Move generic mmap layout functions to mm
  arm64, mm: Make randomization selected by generic topdown mmap layout
  arm: Properly account for stack randomization and stack guard gap
  arm: Use STACK_TOP when computing mmap base address
  arm: Use generic mmap top-down layout and brk randomization
  mips: Properly account for stack randomization and stack guard gap
  mips: Use STACK_TOP when computing mmap base address
  mips: Adjust brk randomization offset to fit generic version
  mips: Replace arch specific way to determine 32bit task with generic
    version
  mips: Use generic mmap top-down layout and brk randomization
  riscv: Make mmap allocation top-down by default

 arch/Kconfig                       |  11 +++
 arch/arm/Kconfig                   |   2 +-
 arch/arm/include/asm/processor.h   |   2 -
 arch/arm/kernel/process.c          |   5 --
 arch/arm/mm/mmap.c                 |  52 --------------
 arch/arm64/Kconfig                 |   2 +-
 arch/arm64/include/asm/processor.h |   2 -
 arch/arm64/kernel/process.c        |   8 ---
 arch/arm64/mm/mmap.c               |  72 -------------------
 arch/mips/Kconfig                  |   2 +-
 arch/mips/include/asm/processor.h  |   5 --
 arch/mips/mm/mmap.c                |  84 ----------------------
 arch/riscv/Kconfig                 |  13 ++++
 fs/binfmt_elf.c                    |  20 ------
 include/linux/mm.h                 |   2 +
 kernel/sysctl.c                    |   6 +-
 mm/util.c                          | 107 ++++++++++++++++++++++++++++-
 17 files changed, 139 insertions(+), 256 deletions(-)

-- 
2.20.1


^ permalink raw reply	[flat|nested] 55+ messages in thread

end of thread, other threads:[~2019-07-31 22:40 UTC | newest]

Thread overview: 55+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-07-30  5:50 [PATCH v5 00/14] Provide generic top-down mmap layout functions Alexandre Ghiti
2019-07-30  5:50 ` Alexandre Ghiti
2019-07-30  5:50 ` Alexandre Ghiti
2019-07-30  5:51 ` [PATCH v5 01/14] mm, fs: Move randomize_stack_top from fs to mm Alexandre Ghiti
2019-07-30  5:51   ` Alexandre Ghiti
2019-07-30  5:51   ` Alexandre Ghiti
2019-07-30  5:51 ` [PATCH v5 02/14] arm64: Make use of is_compat_task instead of hardcoding this test Alexandre Ghiti
2019-07-30  5:51   ` Alexandre Ghiti
2019-07-30  5:51   ` Alexandre Ghiti
2019-07-30  5:51 ` [PATCH v5 03/14] arm64: Consider stack randomization for mmap base only when necessary Alexandre Ghiti
2019-07-30  5:51   ` Alexandre Ghiti
2019-07-30  5:51   ` Alexandre Ghiti
2019-07-30  5:51 ` [PATCH v5 04/14] arm64, mm: Move generic mmap layout functions to mm Alexandre Ghiti
2019-07-30  5:51   ` Alexandre Ghiti
2019-07-30  5:51   ` Alexandre Ghiti
2019-07-30  5:51 ` [PATCH v5 05/14] arm64, mm: Make randomization selected by generic topdown mmap layout Alexandre Ghiti
2019-07-30  5:51   ` Alexandre Ghiti
2019-07-30  5:51   ` Alexandre Ghiti
2019-07-30  5:51 ` [PATCH v5 06/14] arm: Properly account for stack randomization and stack guard gap Alexandre Ghiti
2019-07-30  5:51   ` Alexandre Ghiti
2019-07-30  5:51   ` Alexandre Ghiti
2019-07-30  5:51 ` [PATCH v5 07/14] arm: Use STACK_TOP when computing mmap base address Alexandre Ghiti
2019-07-30  5:51   ` Alexandre Ghiti
2019-07-30  5:51   ` Alexandre Ghiti
2019-07-30  5:51 ` [PATCH v5 08/14] arm: Use generic mmap top-down layout and brk randomization Alexandre Ghiti
2019-07-30  5:51   ` Alexandre Ghiti
2019-07-30  5:51   ` Alexandre Ghiti
2019-07-30  5:51 ` [PATCH v5 09/14] mips: Properly account for stack randomization and stack guard gap Alexandre Ghiti
2019-07-30  5:51   ` Alexandre Ghiti
2019-07-30  5:51   ` Alexandre Ghiti
2019-07-30  5:51 ` [PATCH v5 10/14] mips: Use STACK_TOP when computing mmap base address Alexandre Ghiti
2019-07-30  5:51   ` Alexandre Ghiti
2019-07-30  5:51   ` Alexandre Ghiti
2019-07-30  5:51 ` [PATCH v5 11/14] mips: Adjust brk randomization offset to fit generic version Alexandre Ghiti
2019-07-30  5:51   ` Alexandre Ghiti
2019-07-30  5:51   ` Alexandre Ghiti
2019-07-30  5:51 ` [PATCH v5 12/14] mips: Replace arch specific way to determine 32bit task with " Alexandre Ghiti
2019-07-30  5:51   ` Alexandre Ghiti
2019-07-30  5:51   ` Alexandre Ghiti
2019-07-30  5:51 ` [PATCH v5 13/14] mips: Use generic mmap top-down layout and brk randomization Alexandre Ghiti
2019-07-30  5:51   ` Alexandre Ghiti
2019-07-30  5:51   ` Alexandre Ghiti
2019-07-30  5:51 ` [PATCH v5 14/14] riscv: Make mmap allocation top-down by default Alexandre Ghiti
2019-07-30  5:51   ` Alexandre Ghiti
2019-07-30  5:51   ` Alexandre Ghiti
2019-07-31  6:05   ` Alex Ghiti
2019-07-31  6:05     ` Alex Ghiti
2019-07-31  6:05     ` Alex Ghiti
2019-07-31 17:33     ` Guenter Roeck
2019-07-31 17:33       ` Guenter Roeck
2019-07-31 17:33       ` Guenter Roeck
2019-07-31 22:40   ` Paul Walmsley
2019-07-31 22:40     ` Paul Walmsley
2019-07-31 22:40     ` Paul Walmsley
2019-07-31 22:40     ` Paul Walmsley

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