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Palmer Dabbelt 8aeb7b17f0
RISC-V: Make mmap() with PROT_WRITE imply PROT_READ
Commit 2139619bca ("riscv: mmap with PROT_WRITE but no PROT_READ is
invalid") made mmap() reject mappings with only PROT_WRITE set in an
attempt to fix an observed inconsistency in behavior when attempting
to read from a PROT_WRITE-only mapping. The root cause of this behavior
was actually that while RISC-V's protection_map maps VM_WRITE to
readable PTE permissions (since write-only PTEs are considered reserved
by the privileged spec), the page fault handler considered loads from
VM_WRITE-only VMAs illegal accesses. Fix the underlying cause by
handling faults in VM_WRITE-only VMAs (patch 1) and then re-enable
use of mmap(PROT_WRITE) (patch 2), making RISC-V's behavior consistent
with all other architectures that don't support write-only PTEs.

* remotes/palmer/riscv-wonly:
  riscv: Allow PROT_WRITE-only mmap()
  riscv: Make VM_WRITE imply VM_READ

Link: https://lore.kernel.org/r/20220915193702.2201018-1-abrestic@rivosinc.com/
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-10-13 12:49:12 -07:00
arch RISC-V: Make mmap() with PROT_WRITE imply PROT_READ 2022-10-13 12:49:12 -07:00
block for-6.1/passthrough-2022-10-04 2022-10-07 09:35:50 -07:00
certs certs: make system keyring depend on built-in x509 parser 2022-09-24 04:31:18 +09:00
crypto crypto: blake2b: effectively disable frame size warning 2022-08-10 17:59:11 -07:00
Documentation Merge patch series "Use composable cache instead of L2 cache" 2022-10-13 11:07:13 -07:00
drivers RISC-V: Re-enable counter access from userspace 2022-10-13 11:18:39 -07:00
fs The first batch of KVM patches, mostly covering x86, which I 2022-10-09 09:39:55 -07:00
include Merge patch series "Use composable cache instead of L2 cache" 2022-10-13 11:07:13 -07:00
init Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
io_uring for-6.1/passthrough-2022-10-04 2022-10-07 09:35:50 -07:00
ipc Updates to various subsystems which I help look after. lib, ocfs2, 2022-08-07 10:03:24 -07:00
kernel Driver core changes for 6.1-rc1 2022-10-07 17:04:10 -07:00
lib Driver core changes for 6.1-rc1 2022-10-07 17:04:10 -07:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm The first batch of KVM patches, mostly covering x86, which I 2022-10-09 09:39:55 -07:00
net Driver core changes for 6.1-rc1 2022-10-07 17:04:10 -07:00
rust Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
samples ARM: driver updates for 6.1 2022-10-06 11:04:57 -07:00
scripts Networking changes for 6.1. 2022-10-04 13:38:03 -07:00
security whack-a-mole: constifying struct path * 2022-10-06 17:31:02 -07:00
sound sound updates for 6.1-rc1 2022-10-05 12:02:07 -07:00
tools The first batch of KVM patches, mostly covering x86, which I 2022-10-09 09:39:55 -07:00
usr Not a lot of material this cycle. Many singleton patches against various 2022-05-27 11:22:03 -07:00
virt KVM: remove KVM_REQ_UNHALT 2022-09-26 12:37:21 -04:00
.clang-format PCI/DOE: Add DOE mailbox support functions 2022-07-19 15:38:04 -07:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
.mailmap The first batch of KVM patches, mostly covering x86, which I 2022-10-09 09:39:55 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS drm for 5.20/6.0 2022-08-03 19:52:08 -07:00
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 dt-bindings: riscv: update microchip.yaml's maintainership 2022-10-11 12:39:14 -07:00
Makefile hardening updates for v6.1-rc1 2022-10-03 17:24:22 -07:00
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.