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Björn Töpel 9657e9b7d2
riscv: Discard vector state on syscalls
The RISC-V vector specification states:
  Executing a system call causes all caller-saved vector registers
  (v0-v31, vl, vtype) and vstart to become unspecified.

The vector registers are set to all 1s, vill is set (invalid), and the
vector status is set to Dirty.

That way we can prevent userspace from accidentally relying on the
stated save.

Rémi pointed out [1] that writing to the registers might be
superfluous, and setting vill is sufficient.

Link: https://lore.kernel.org/linux-riscv/12784326.9UPPK3MAeB@basile.remlab.net/ # [1]
Suggested-by: Darius Rad <darius@bluespec.com>
Suggested-by: Palmer Dabbelt <palmer@rivosinc.com>
Suggested-by: Rémi Denis-Courmont <remi@remlab.net>
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/r/20230629142228.1125715-1-bjorn@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-07-04 08:59:24 -07:00
arch riscv: Discard vector state on syscalls 2023-07-04 08:59:24 -07:00
block - Yosry Ahmed brought back some cgroup v1 stats in OOM logs. 2023-06-28 10:28:11 -07:00
certs KEYS: Add missing function documentation 2023-04-24 16:15:52 +03:00
crypto sock: Remove ->sendpage*() in favour of sendmsg(MSG_SPLICE_PAGES) 2023-06-24 15:50:13 -07:00
Documentation RISC-V: Document that V registers are clobbered on syscalls 2023-07-01 07:38:16 -07:00
drivers RISC-V Patches for the 6.5 Merge Window, Part 1 2023-06-30 09:37:26 -07:00
fs \n 2023-06-29 13:39:51 -07:00
include Merge patch series "riscv: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION" 2023-07-01 07:38:19 -07:00
init - Arnd Bergmann has fixed a bunch of -Wmissing-prototypes in 2023-06-28 10:59:38 -07:00
io_uring \n 2023-06-29 13:31:44 -07:00
ipc Merge branch 'work.namespace' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2023-02-24 19:20:07 -08:00
kernel RISC-V Patches for the 6.5 Merge Window, Part 1 2023-06-30 09:37:26 -07:00
lib Networking changes for 6.5. 2023-06-28 16:43:10 -07:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm memblock: small updates for 6.5-rc1 2023-06-29 23:21:20 -07:00
net Networking changes for 6.5. 2023-06-28 16:43:10 -07:00
rust rust: error: impl Debug for Error with errname() integration 2023-06-13 01:24:42 +02:00
samples Networking changes for 6.5. 2023-06-28 16:43:10 -07:00
scripts powerpc updates for 6.5 2023-06-30 09:20:08 -07:00
security powerpc updates for 6.5 2023-06-30 09:20:08 -07:00
sound ARM: SoC changes for 6.5 2023-06-29 15:28:33 -07:00
tools selftests: Test RISC-V Vector's first-use handler 2023-07-01 07:38:22 -07:00
usr initramfs: Check negative timestamp to prevent broken cpio archive 2023-04-16 17:37:01 +09:00
virt - Yosry Ahmed brought back some cgroup v1 stats in OOM logs. 2023-06-28 10:28:11 -07:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore linux-kselftest-kunit-6.4-rc1 2023-04-24 12:31:32 -07:00
.mailmap drm changes for 6.5-rc1: 2023-06-29 11:00:17 -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 - Address -Wmissing-prototype warnings 2023-06-26 16:43:54 -07:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS RISC-V Patches for the 6.5 Merge Window, Part 1 2023-06-30 09:37:26 -07:00
Makefile hardening updates for v6.5-rc1 2023-06-27 21:24:18 -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.