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Christophe Leroy 6b932920b9 mm, hugetlb: allow for "high" userspace addresses 
commit 5f24d5a579d1eace79d505b148808a850b417d4c upstream.

This is a fix for commit f6795053da ("mm: mmap: Allow for "high"
userspace addresses") for hugetlb.

This patch adds support for "high" userspace addresses that are
optionally supported on the system and have to be requested via a hint
mechanism ("high" addr parameter to mmap).

Architectures such as powerpc and x86 achieve this by making changes to
their architectural versions of hugetlb_get_unmapped_area() function.
However, arm64 uses the generic version of that function.

So take into account arch_get_mmap_base() and arch_get_mmap_end() in
hugetlb_get_unmapped_area().  To allow that, move those two macros out
of mm/mmap.c into include/linux/sched/mm.h

If these macros are not defined in architectural code then they default
to (TASK_SIZE) and (base) so should not introduce any behavioural
changes to architectures that do not define them.

For the time being, only ARM64 is affected by this change.

Catalin (ARM64) said
 "We should have fixed hugetlb_get_unmapped_area() as well when we added
  support for 52-bit VA. The reason for commit f6795053da was to
  prevent normal mmap() from returning addresses above 48-bit by default
  as some user-space had hard assumptions about this.

  It's a slight ABI change if you do this for hugetlb_get_unmapped_area()
  but I doubt anyone would notice. It's more likely that the current
  behaviour would cause issues, so I'd rather have them consistent.

  Basically when arm64 gained support for 52-bit addresses we did not
  want user-space calling mmap() to suddenly get such high addresses,
  otherwise we could have inadvertently broken some programs (similar
  behaviour to x86 here). Hence we added commit f6795053da. But we
  missed hugetlbfs which could still get such high mmap() addresses. So
  in theory that's a potential regression that should have bee addressed
  at the same time as commit f6795053da (and before arm64 enabled
  52-bit addresses)"

Link: https://lkml.kernel.org/r/ab847b6edb197bffdfe189e70fb4ac76bfe79e0d.1650033747.git.christophe.leroy@csgroup.eu
Fixes: f6795053da ("mm: mmap: Allow for "high" userspace addresses")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Steve Capper <steve.capper@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: <stable@vger.kernel.org>	[5.0.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 		2022-04-27 13:53:54 +02:00
Documentation docs: sysctl/kernel: add missing bit to panic_print 2022-04-08 14:40:44 +02:00
LICENSES
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arch stat: fix inconsistency between struct stat and struct compat_stat 2022-04-27 13:53:54 +02:00
block Revert "Revert "block, bfq: honor already-setup queue merges"" 2022-04-08 14:40:32 +02:00
certs
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crypto
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drivers EDAC/synopsys: Read the error count from the correct register 2022-04-27 13:53:54 +02:00
fs mm, hugetlb: allow for "high" userspace addresses 2022-04-27 13:53:54 +02:00
include mm, hugetlb: allow for "high" userspace addresses 2022-04-27 13:53:54 +02:00
init init/main.c: return 1 from handled __setup() functions 2022-04-13 21:01:01 +02:00
ipc
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kernel tracing: Dump stacktrace trigger to the corresponding instance 2022-04-27 13:53:46 +02:00
lib ubsan: remove CONFIG_UBSAN_OBJECT_SIZE 2022-04-13 21:01:10 +02:00
mm mm, hugetlb: allow for "high" userspace addresses 2022-04-27 13:53:54 +02:00
net netlink: reset network and mac headers in netlink_dump() 2022-04-27 13:53:51 +02:00
samples
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scripts gcc-plugins: latent_entropy: use /dev/urandom 2022-04-20 09:23:26 +02:00
security
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sound ALSA: usb-audio: Fix undefined behavior due to shift overflowing the constant 2022-04-27 13:53:53 +02:00
tools selftests: mlxsw: vxlan_flooding: Prevent flooding of unwanted packets 2022-04-27 13:53:52 +02:00
usr
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virt KVM: Prevent module exit until all VMs are freed 2022-04-08 14:40:38 +02:00
.clang-format
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.cocciconfig
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.get_maintainer.ignore
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.gitattributes
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.gitignore
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.mailmap
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COPYING
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CREDITS
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Kbuild
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Kconfig
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MAINTAINERS
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Makefile Linux 5.10.112 2022-04-20 09:23:32 +02:00
README
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README 

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.