tjh.dev
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.
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
code
Clone this repository
https://tangled.org/tjh.dev/kernel
git@gordian.tjh.dev:tjh.dev/kernel
For self-hosted knots, clone URLs may differ based on your setup.
Pull Kbuild fixes from Masahiro Yamada:
- Move non-boot built-in DTBs to the .rodata section
- Fix Kconfig bugs
- Fix maint scripts in the linux-image Debian package
- Import some list macros to scripts/include/
* tag 'kbuild-fixes-v6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kbuild: deb-pkg: Remove blank first line from maint scripts
kbuild: fix a typo dt_binding_schema -> dt_binding_schemas
scripts: import more list macros
kconfig: qconf: fix buffer overflow in debug links
kconfig: qconf: move conf_read() before drawing tree pain
kconfig: clear expr::val_is_valid when allocated
kconfig: fix infinite loop in sym_calc_choice()
kbuild: move non-boot built-in DTBs to .rodata section
Pull x86 platform driver fixes from Hans de Goede:
- Intel PMC fix for suspend/resume issues on some Sky and Kaby Lake
laptops
- Intel Diamond Rapids hw-id additions
- Documentation and MAINTAINERS fixes
- Some other small fixes
* tag 'platform-drivers-x86-v6.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86:
platform/x86: x86-android-tablets: Fix use after free on platform_device_register() errors
platform/x86: wmi: Update WMI driver API documentation
platform/x86: dell-ddv: Fix typo in documentation
platform/x86: dell-sysman: add support for alienware products
platform/x86/intel: power-domains: Add Diamond Rapids support
platform/x86: ISST: Add Diamond Rapids to support list
platform/x86:intel/pmc: Disable ACPI PM Timer disabling on Sky and Kaby Lake
platform/x86: dell-laptop: Do not fail when encountering unsupported batteries
MAINTAINERS: Update Intel In Field Scan(IFS) entry
platform/x86: ISST: Fix the KASAN report slab-out-of-bounds bug
The blank line causes execve() to fail:
# strace ./postinst
execve("./postinst", ...) = -1 ENOEXEC (Exec format error)
strace: exec: Exec format error
+++ exited with 1 +++
However running the scripts via shell does work (at least with bash)
because the shell attempts to execute the file as a shell script when
execve() fails.
Fixes: b611daae5efc ("kbuild: deb-pkg: split image and debug objects staging out into functions")
Signed-off-by: Aaron Thompson <dev@aaront.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Pull kvm fixes from Paolo Bonzini:
"ARM64:
- Fix pKVM error path on init, making sure we do not change critical
system registers as we're about to fail
- Make sure that the host's vector length is at capped by a value
common to all CPUs
- Fix kvm_has_feat*() handling of "negative" features, as the current
code is pretty broken
- Promote Joey to the status of official reviewer, while James steps
down -- hopefully only temporarly
x86:
- Fix compilation with KVM_INTEL=KVM_AMD=n
- Fix disabling KVM_X86_QUIRK_SLOT_ZAP_ALL when shadow MMU is in use
Selftests:
- Fix compilation on non-x86 architectures"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
x86/reboot: emergency callbacks are now registered by common KVM code
KVM: x86: leave kvm.ko out of the build if no vendor module is requested
KVM: x86/mmu: fix KVM_X86_QUIRK_SLOT_ZAP_ALL for shadow MMU
KVM: arm64: Fix kvm_has_feat*() handling of negative features
KVM: selftests: Fix build on architectures other than x86_64
KVM: arm64: Another reviewer reshuffle
KVM: arm64: Constrain the host to the maximum shared SVE VL with pKVM
KVM: arm64: Fix __pkvm_init_vcpu cptr_el2 error path
x86_android_tablet_remove() frees the pdevs[] array, so it should not
be used after calling x86_android_tablet_remove().
When platform_device_register() fails, store the pdevs[x] PTR_ERR() value
into the local ret variable before calling x86_android_tablet_remove()
to avoid using pdevs[] after it has been freed.
Fixes: 5eba0141206e ("platform/x86: x86-android-tablets: Add support for instantiating platform-devs")
Fixes: e2200d3f26da ("platform/x86: x86-android-tablets: Add gpio_keys support to x86_android_tablet_init()")
Cc: stable@vger.kernel.org
Reported-by: Aleksandr Burakov <a.burakov@rosalinux.ru>
Closes: https://lore.kernel.org/platform-driver-x86/20240917120458.7300-1-a.burakov@rosalinux.ru/
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20241005130545.64136-1-hdegoede@redhat.com
If we follow "make help" to "make dt_binding_schema", we will see
below error:
$ make dt_binding_schema
make[1]: *** No rule to make target 'dt_binding_schema'. Stop.
make: *** [Makefile:224: __sub-make] Error 2
It should be a typo. So this will fix it.
Fixes: 604a57ba9781 ("dt-bindings: kbuild: Add separate target/dependency for processed-schema.json")
Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Pull powerpc fix from Michael Ellerman:
- Allow r30 to be used in vDSO code generation of getrandom
Thanks to Jason A. Donenfeld
* tag 'powerpc-6.12-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/vdso: allow r30 in vDSO code generation of getrandom
KVM/arm64 fixes for 6.12, take #1
- Fix pKVM error path on init, making sure we do not change critical
system registers as we're about to fail
- Make sure that the host's vector length is at capped by a value
common to all CPUs
- Fix kvm_has_feat*() handling of "negative" features, as the current
code is pretty broken
- Promote Joey to the status of official reviewer, while James steps
down -- hopefully only temporarly
The WMI driver core now passes the WMI event data to legacy notify
handlers, so WMI devices sharing notification IDs are now being
handled properly.
Fixes: e04e2b760ddb ("platform/x86: wmi: Pass event data directly to legacy notify handlers")
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20241005213825.701887-1-W_Armin@gmx.de
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Import list_is_first, list_is_last, list_replace, and list_replace_init.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Pull bcachefs fixes from Kent Overstreet:
"A lot of little fixes, bigger ones include:
- bcachefs's __wait_on_freeing_inode() was broken in rc1 due to vfs
changes, now fixed along with another lost wakeup
- fragmentation LRU fixes; fsck now repairs successfully (this is the
data structure copygc uses); along with some nice simplification.
- Rework logged op error handling, so that if logged op replay errors
(due to another filesystem error) we delete the logged op instead
of going into an infinite loop)
- Various small filesystem connectivitity repair fixes"
* tag 'bcachefs-2024-10-05' of git://evilpiepirate.org/bcachefs:
bcachefs: Rework logged op error handling
bcachefs: Add warn param to subvol_get_snapshot, peek_inode
bcachefs: Kill snapshot arg to fsck_write_inode()
bcachefs: Check for unlinked, non-empty dirs in check_inode()
bcachefs: Check for unlinked inodes with dirents
bcachefs: Check for directories with no backpointers
bcachefs: Kill alloc_v4.fragmentation_lru
bcachefs: minor lru fsck fixes
bcachefs: Mark more errors AUTOFIX
bcachefs: Make sure we print error that causes fsck to bail out
bcachefs: bkey errors are only AUTOFIX during read
bcachefs: Create lost+found in correct snapshot
bcachefs: Fix reattach_inode()
bcachefs: Add missing wakeup to bch2_inode_hash_remove()
bcachefs: Fix trans_commit disk accounting revert
bcachefs: Fix bch2_inode_is_open() check
bcachefs: Fix return type of dirent_points_to_inode_nowarn()
bcachefs: Fix bad shift in bch2_read_flag_list()
For gettimeofday, -ffixed-r30 was passed to work around a bug in Go
code, where the vDSO trampoline forgot to save and restore this register
across function calls. But Go requires a different trampoline for every
call, and there's no reason that new Go code needs to be broken and add
more bugs. So remove -ffixed-r30 for getrandom.
Fixes: 8072b39c3a75 ("powerpc/vdso: Wire up getrandom() vDSO implementation on VDSO64")
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240925175021.1526936-2-Jason@zx2c4.com
Guard them with CONFIG_KVM_X86_COMMON rather than the two vendor modules.
In practice this has no functional change, because CONFIG_KVM_X86_COMMON
is set if and only if at least one vendor-specific module is being built.
However, it is cleaner to specify CONFIG_KVM_X86_COMMON for functions that
are used in kvm.ko.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Fixes: 590b09b1d88e ("KVM: x86: Register "emergency disable" callbacks when virt is enabled")
Fixes: 6d55a94222db ("x86/reboot: Unconditionally define cpu_emergency_virt_cb typedef")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Oliver reports that the kvm_has_feat() helper is not behaviing as
expected for negative feature. On investigation, the main issue
seems to be caused by the following construct:
#define get_idreg_field(kvm, id, fld) \
(id##_##fld##_SIGNED ? \
get_idreg_field_signed(kvm, id, fld) : \
get_idreg_field_unsigned(kvm, id, fld))
where one side of the expression evaluates as something signed,
and the other as something unsigned. In retrospect, this is totally
braindead, as the compiler converts this into an unsigned expression.
When compared to something that is 0, the test is simply elided.
Epic fail. Similar issue exists in the expand_field_sign() macro.
The correct way to handle this is to chose between signed and unsigned
comparisons, so that both sides of the ternary expression are of the
same type (bool).
In order to keep the code readable (sort of), we introduce new
comparison primitives taking an operator as a parameter, and
rewrite the kvm_has_feat*() helpers in terms of these primitives.
Fixes: c62d7a23b947 ("KVM: arm64: Add feature checking helpers")
Reported-by: Oliver Upton <oliver.upton@linux.dev>
Tested-by: Oliver Upton <oliver.upton@linux.dev>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20241002204239.2051637-1-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Fix typo in word 'diagnostics' in documentation.
Signed-off-by: Anaswara T Rajan <anaswaratrajan@gmail.com>
Reviewed-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20241005070056.16326-1-anaswaratrajan@gmail.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
README