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* [PATCH 0/6] arm64: untag user pointers passed to the kernel
@ 2018-04-18 18:53 Andrey Konovalov
  2018-04-18 18:53 ` [PATCH 1/6] arm64: add type casts to untagged_addr macro Andrey Konovalov
                   ` (6 more replies)
  0 siblings, 7 replies; 21+ messages in thread
From: Andrey Konovalov @ 2018-04-18 18:53 UTC (permalink / raw)
  To: Catalin Marinas, Will Deacon, Jonathan Corbet, Mark Rutland,
	Robin Murphy, Al Viro, Andrey Konovalov, James Morse, Kees Cook,
	Bart Van Assche, Kate Stewart, Greg Kroah-Hartman,
	Thomas Gleixner, Philippe Ombredanne, Andrew Morton, Ingo Molnar,
	Kirill A . Shutemov, Dan Williams, Aneesh Kumar K . V, Zi Yan,
	linux-arm-kernel, linux-doc, linux-kernel, linux-mm
  Cc: Dmitry Vyukov, Kostya Serebryany, Evgeniy Stepanov, Lee Smith,
	Ramana Radhakrishnan, Jacob Bramley, Ruben Ayrapetyan

Hi!

arm64 has a feature called Top Byte Ignore, which allows to embed pointer
tags into the top byte of each pointer. Userspace programs (such as
HWASan, a memory debugging tool [1]) might use this feature and pass
tagged user pointers to the kernel through syscalls or other interfaces.

This patch makes a few of the kernel interfaces accept tagged user
pointers. The kernel is already able to handle user faults with tagged
pointers and has the untagged_addr macro, which this patchset reuses.

We're not trying to cover all possible ways the kernel accepts user
pointers in one patchset, so this one should be considered as a start.

Thanks!

[1] http://clang.llvm.org/docs/HardwareAssistedAddressSanitizerDesign.html

Changes in v1:
- Rebased onto 4.17-rc1.

Changes in RFC v2:
- Added "#ifndef untagged_addr..." fallback in linux/uaccess.h instead of
  defining it for each arch individually.
- Updated Documentation/arm64/tagged-pointers.txt.
- Dropped “mm, arm64: untag user addresses in memory syscalls”.
- Rebased onto 3eb2ce82 (4.16-rc7).

Andrey Konovalov (6):
  arm64: add type casts to untagged_addr macro
  uaccess: add untagged_addr definition for other arches
  arm64: untag user addresses in copy_from_user and others
  mm, arm64: untag user addresses in mm/gup.c
  lib, arm64: untag addrs passed to strncpy_from_user and strnlen_user
  arm64: update Documentation/arm64/tagged-pointers.txt

 Documentation/arm64/tagged-pointers.txt |  5 +++--
 arch/arm64/include/asm/uaccess.h        |  9 +++++++--
 include/linux/uaccess.h                 |  4 ++++
 lib/strncpy_from_user.c                 |  2 ++
 lib/strnlen_user.c                      |  2 ++
 mm/gup.c                                | 12 ++++++++++++
 6 files changed, 30 insertions(+), 4 deletions(-)

-- 
2.17.0.484.g0c8726318c-goog

^ permalink raw reply	[flat|nested] 21+ messages in thread

end of thread, other threads:[~2018-05-11 12:36 UTC | newest]

Thread overview: 21+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-04-18 18:53 [PATCH 0/6] arm64: untag user pointers passed to the kernel Andrey Konovalov
2018-04-18 18:53 ` [PATCH 1/6] arm64: add type casts to untagged_addr macro Andrey Konovalov
2018-04-18 18:53 ` [PATCH 2/6] uaccess: add untagged_addr definition for other arches Andrey Konovalov
2018-04-18 18:53 ` [PATCH 3/6] arm64: untag user addresses in copy_from_user and others Andrey Konovalov
2018-04-26 15:47   ` Catalin Marinas
2018-05-02 15:29     ` Andrey Konovalov
2018-04-18 18:53 ` [PATCH 4/6] mm, arm64: untag user addresses in mm/gup.c Andrey Konovalov
2018-04-26 17:47   ` Catalin Marinas
2018-05-02 14:38     ` Andrey Konovalov
2018-05-02 15:36       ` Kirill A. Shutemov
2018-05-02 17:25         ` Andrey Konovalov
2018-05-03 14:09           ` Andrey Konovalov
2018-05-03 15:24             ` Kirill A. Shutemov
2018-05-03 16:51               ` Andrey Konovalov
2018-05-08 15:11           ` Catalin Marinas
2018-05-11 12:36             ` Andrey Konovalov
2018-04-18 18:53 ` [PATCH 5/6] lib, arm64: untag addrs passed to strncpy_from_user and strnlen_user Andrey Konovalov
2018-04-18 18:53 ` [PATCH 6/6] arm64: update Documentation/arm64/tagged-pointers.txt Andrey Konovalov
2018-04-19  9:33 ` [PATCH 0/6] arm64: untag user pointers passed to the kernel Kirill A. Shutemov
2018-04-25 14:45   ` Andrey Konovalov
2018-04-26 17:56     ` Catalin Marinas

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