No description
Find a file
Christophe Leroy 9dcb65cdf3 mm, hugetlb: allow for "high" userspace addresses
commit 5f24d5a579 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 14:38:57 +02:00
arch stat: fix inconsistency between struct stat and struct compat_stat 2022-04-27 14:38:57 +02:00
block block: simplify the block device syncing code 2022-04-27 14:38:50 +02:00
certs certs: Add support for using elliptic curve keys for signing modules 2021-08-23 19:55:42 +03:00
crypto crypto: xts - Add softdep on ecb 2022-04-08 14:23:55 +02:00
Documentation dt-bindings: net: snps: remove duplicate name 2022-04-20 09:34:21 +02:00
drivers EDAC/synopsys: Read the error count from the correct register 2022-04-27 14:38:57 +02:00
fs mm, hugetlb: allow for "high" userspace addresses 2022-04-27 14:38:57 +02:00
include mm, hugetlb: allow for "high" userspace addresses 2022-04-27 14:38:57 +02:00
init init/main.c: return 1 from handled __setup() functions 2022-04-13 20:59:10 +02:00
ipc ipc/sem: do not sleep with a spin lock held 2022-02-08 18:34:03 +01:00
kernel dma-mapping: remove bogus test for pfn_valid from dma_map_resource 2022-04-27 14:38:50 +02:00
lib stacktrace: move filter_irq_stacks() to kernel/stacktrace.c 2022-04-13 20:59:28 +02:00
LICENSES LICENSES/dual/CC-BY-4.0: Git rid of "smart quotes" 2021-07-15 06:31:24 -06:00
mm mm, hugetlb: allow for "high" userspace addresses 2022-04-27 14:38:57 +02:00
net netlink: reset network and mac headers in netlink_dump() 2022-04-27 14:38:54 +02:00
samples samples/bpf, xdpsock: Fix race when running for fix duration of time 2022-04-08 14:23:40 +02:00
scripts gcc-plugins: latent_entropy: use /dev/urandom 2022-04-20 09:34:18 +02:00
security Fix incorrect type in assignment of ipv6 port for audit 2022-04-08 14:23:55 +02:00
sound ALSA: usb-audio: Fix undefined behavior due to shift overflowing the constant 2022-04-27 14:38:55 +02:00
tools selftests: mlxsw: vxlan_flooding: Prevent flooding of unwanted packets 2022-04-27 14:38:55 +02:00
usr usr/include/Makefile: add linux/nfc.h to the compile-test coverage 2022-02-01 17:27:15 +01:00
virt KVM: avoid NULL pointer dereference in kvm_dirty_ring_push 2022-04-13 20:59:26 +02:00
.clang-format clang-format: Update with the latest for_each macro list 2021-05-12 23:32:39 +02:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: ignore only top-level modules.builtin 2021-05-02 00:43:35 +09:00
.mailmap mailmap: add Andrej Shadura 2021-10-18 20:22:03 -10:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Daniel Drake to credits 2021-09-21 08:34:58 +03:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS MAINTAINERS: adjust file entry for of_net.c after movement 2022-03-08 19:12:53 +01:00
Makefile Linux 5.15.35 2022-04-20 09:34:22 +02:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.