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Mark Rutland 78b23877db kselftest/arm64: fp-ptrace: Fix expected FPMR value when PSTATE.SM is changed The fp-ptrace test suite expects that FPMR is set to zero when PSTATE.SM is changed via ptrace, but ptrace has never altered FPMR in this way, and the test logic erroneously relies upon (and has concealed) a bug where task_fpsimd_load() would unexpectedly and non-deterministically clobber FPMR. Using ptrace, FPMR can only be altered by writing to the NT_ARM_FPMR regset. The value of PSTATE.SM can be altered by writing to the NT_ARM_SVE or NT_ARM_SSVE regsets, and/or by changing the SME vector length (when writing to the NT_ARM_SVE, NT_ARM_SSVE, or NT_ARM_ZA regsets), but none of these writes will change the value of FPMR. The task_fpsimd_load() bug was introduced with the initial FPMR support in commit: `203f2b95a8` ("arm64/fpsimd: Support FEAT_FPMR") The incorrect FPMR test code was introduced in commit: `7dbd26d0b2` ("kselftest/arm64: Add FPMR coverage to fp-ptrace") Subsequently, the task_fpsimd_load() bug was fixed in commit: `e5fa85fce0` ("arm64/fpsimd: Don't corrupt FPMR when streaming mode changes") ... whereupon the fp-ptrace FPMR tests started failing reliably, e.g. \| # # Mismatch in saved FPMR: 915058000 != 0 \| # not ok 25 SVE write, SVE 64->64, SME 64/0->64/1 Fix this by changing the test to expect that FPMR is NOT changed when PSTATE.SM is changed via ptrace, matching the extant behaviour. I've chosen to update the test code rather than modifying ptrace to zero FPMR when PSTATE.SM changes. Not zeroing FPMR is simpler overall, and allows the NT_ARM_FPMR regset to be handled independently from other regsets, leaving less scope for error. Fixes: `7dbd26d0b2` ("kselftest/arm64: Add FPMR coverage to fp-ptrace") Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Spickett <david.spickett@arm.com> Cc: Luis Machado <luis.machado@arm.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Mark Brown <broonie@kernel.org> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20250508132644.1395904-22-mark.rutland@arm.com Signed-off-by: Will Deacon <will@kernel.org>		2025-05-08 15:45:24 +01:00
arch	A set of final cleanups for the timer subsystem:	2025-04-06 08:35:37 -07:00
block	treewide: Switch/rename to timer_delete[_sync]()	2025-04-05 10:30:12 +02:00
certs	sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3	2024-09-20 19:52:48 +03:00
crypto	This push fixes reverts the multibuffer hash testing as it is buggy.	2025-04-02 09:14:59 -07:00
Documentation	A set of final cleanups for the timer subsystem:	2025-04-06 08:35:37 -07:00
drivers	A set of final cleanups for the timer subsystem:	2025-04-06 08:35:37 -07:00
fs	Miscellaneous scheduler fixes/updates:	2025-04-06 10:44:58 -07:00
include	A set of final cleanups for the timer subsystem:	2025-04-06 08:35:37 -07:00
init	Miscellaneous scheduler fixes/updates:	2025-04-06 10:44:58 -07:00
io_uring	io_uring: always do atomic put from iowq	2025-04-03 08:31:57 -06:00
ipc	treewide: const qualify ctl_tables where applicable	2025-01-28 13:48:37 +01:00
kernel	Fix a perf events time accounting bug.	2025-04-06 10:48:12 -07:00
lib	Kbuild updates for v6.15	2025-04-05 15:46:50 -07:00
LICENSES	LICENSES: add 0BSD license text	2024-09-01 20:43:24 -07:00
mm	Disable SLUB_TINY for build testing	2025-04-06 10:00:04 -07:00
net	treewide: Switch/rename to timer_delete[_sync]()	2025-04-05 10:30:12 +02:00
rust	Kbuild updates for v6.15	2025-04-05 15:46:50 -07:00
samples	treewide: Switch/rename to timer_delete[_sync]()	2025-04-05 10:30:12 +02:00
scripts	Disable SLUB_TINY for build testing	2025-04-06 10:00:04 -07:00
security	mseal sysmap: kernel config and header change	2025-04-01 15:17:14 -07:00
sound	soundwire fix for 6.15-rc1	2025-04-06 12:04:53 -07:00
tools	kselftest/arm64: fp-ptrace: Fix expected FPMR value when PSTATE.SM is changed	2025-05-08 15:45:24 +01:00
usr	kbuild: hdrcheck: fix cross build with clang	2025-03-05 04:06:45 +09:00
virt	ARM:	2025-03-25 14:22:07 -07:00
.clang-format	clang-format: Update with v6.11-rc1's `for_each` macro list	2024-08-02 13:20:31 +02:00
.clippy.toml	rust: give Clippy the minimum supported Rust version	2025-01-10 00:17:25 +01:00
.cocciconfig
.editorconfig	.editorconfig: remove trim_trailing_whitespace option	2024-06-13 16:47:52 +02:00
.get_maintainer.ignore	MAINTAINERS: Retire Ralf Baechle	2024-11-12 15:48:59 +01:00
.gitattributes	.gitattributes: set diff driver for Rust source code files	2023-05-31 17:48:25 +02:00
.gitignore	kbuild: Create intermediate vmlinux build with relocations preserved	2025-03-17 00:29:50 +09:00
.mailmap	mailmap: add an entry for Nicolas Schier	2025-04-01 15:20:45 -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	Including fixes from netfilter.	2025-04-04 09:15:35 -07:00
Kbuild	drm: ensure drm headers are self-contained and pass kernel-doc	2025-02-12 10:44:43 +02:00
Kconfig	io_uring: Rename KConfig to Kconfig	2025-02-19 14:53:27 -07:00
MAINTAINERS	Kbuild updates for v6.15	2025-04-05 15:46:50 -07:00
Makefile	Linux 6.15-rc1	2025-04-06 13:11:33 -07:00
README	README: Fix spelling	2024-03-18 03:36:32 -06:00

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 reStructuredText 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.