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.
code
Clone this repository
https://tangled.org/tjh.dev/kernel
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Pull Kselftest fixes from Mickaël Salaün:
"Fix Kselftest's vfork() side effects.
As reported by Kernel Test Robot and Sean Christopherson, some
tests fail since v6.9-rc1 . This is due to the use of vfork() which
introduced some side effects. Similarly, while making it more generic,
a previous commit made some Landlock file system tests flaky, and
subject to the host's file system mount configuration.
This fixes all these side effects by replacing vfork() with clone3()
and CLONE_VFORK, which is cleaner (no arbitrary shared memory) and
makes the Kselftest framework more robust"
Link: https://lore.kernel.org/oe-lkp/202403291015.1fcfa957-oliver.sang@intel.com
Link: https://lore.kernel.org/r/ZjPelW6-AbtYvslu@google.com
Link: https://lore.kernel.org/r/20240511171445.904356-1-mic@digikod.net
* tag 'kselftest-fix-vfork-2024-05-12' of git://git.kernel.org/pub/scm/linux/kernel/git/mic/linux:
selftests/harness: Handle TEST_F()'s explicit exit codes
selftests/harness: Fix vfork() side effects
selftests/harness: Share _metadata between forked processes
selftests/pidfd: Fix wrong expectation
selftests/harness: Constify fixture variants
selftests/landlock: Do not allocate memory in fixture data
selftests/harness: Fix interleaved scheduling leading to race conditions
selftests/harness: Fix fixture teardown
selftests/landlock: Fix FS tests when run on a private mount point
selftests/pidfd: Fix config for pidfd_setns_test
Pull kvm fix from Paolo Bonzini:
- Fix NULL pointer read on s390 in ioctl(KVM_CHECK_EXTENSION) for
/dev/kvm
* tag 'for-linus-6.9' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: s390: Check kvm pointer when testing KVM_CAP_S390_HPAGE_1M
If TEST_F() explicitly calls exit(code) with code different than 0, then
_metadata->exit_code is set to this code (e.g. KVM_ONE_VCPU_TEST()). We
need to keep in mind that _metadata->exit_code can be KSFT_SKIP while
the process exit code is 0.
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Will Drewry <wad@chromium.org>
Reported-by: Sean Christopherson <seanjc@google.com>
Tested-by: Sean Christopherson <seanjc@google.com>
Closes: https://lore.kernel.org/r/ZjPelW6-AbtYvslu@google.com
Fixes: 0710a1a73fb4 ("selftests/harness: Merge TEST_F_FORK() into TEST_F()")
Link: https://lore.kernel.org/r/20240511171445.904356-11-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Pull EDAC fix from Borislav Petkov:
- Fix a race condition when clearing error count bits and toggling the
error interrupt throug the same register, in synopsys_edac
* tag 'edac_urgent_for_v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras:
EDAC/synopsys: Fix ECC status and IRQ control race condition
KVM: s390: Fix for 6.9
Fix wild read on capability check.
Setting the time namespace with CLONE_NEWTIME returns -EUSERS if the
calling thread shares memory with another thread (because of the shared
vDSO), which is the case when it is created with vfork().
Fix pidfd_setns_test by replacing test harness's vfork() call with a
clone3() call with CLONE_VFORK, and an explicit sharing of the
_metadata and self objects.
Replace _metadata->teardown_parent with a new FIXTURE_TEARDOWN_PARENT()
helper that can replace FIXTURE_TEARDOWN(). This is a cleaner approach
and it enables to selectively share the fixture data between the child
process running tests and the parent process running the fixture
teardown. This also avoids updating several tests to not rely on the
self object's copy-on-write property (e.g. storing the returned value of
a fork() call).
Cc: Christian Brauner <brauner@kernel.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Günther Noack <gnoack@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Will Drewry <wad@chromium.org>
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202403291015.1fcfa957-oliver.sang@intel.com
Fixes: 0710a1a73fb4 ("selftests/harness: Merge TEST_F_FORK() into TEST_F()")
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20240511171445.904356-10-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Pull x86 fixes from Borislav Petkov:
- Add a new PCI ID which belongs to a new AMD CPU family 0x1a
- Ensure that that last level cache ID is set in all cases, in the AMD
CPU topology parsing code, in order to prevent invalid scheduling
domain CPU masks
* tag 'x86_urgent_for_v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/topology/amd: Ensure that LLC ID is initialized
x86/amd_nb: Add new PCI IDs for AMD family 0x1a
The race condition around the ECCCLR register access happens in the IRQ
disable method called in the device remove() procedure and in the ECC IRQ
handler:
1. Enable IRQ:
a. ECCCLR = EN_CE | EN_UE
2. Disable IRQ:
a. ECCCLR = 0
3. IRQ handler:
a. ECCCLR = CLR_CE | CLR_CE_CNT | CLR_CE | CLR_CE_CNT
b. ECCCLR = 0
c. ECCCLR = EN_CE | EN_UE
So if the IRQ disabling procedure is called concurrently with the IRQ
handler method the IRQ might be actually left enabled due to the
statement 3c.
The root cause of the problem is that ECCCLR register (which since
v3.10a has been called as ECCCTL) has intermixed ECC status data clear
flags and the IRQ enable/disable flags. Thus the IRQ disabling (clear EN
flags) and handling (write 1 to clear ECC status data) procedures must
be serialised around the ECCCTL register modification to prevent the
race.
So fix the problem described above by adding the spin-lock around the
ECCCLR modifications and preventing the IRQ-handler from modifying the
IRQs enable flags (there is no point in disabling the IRQ and then
re-enabling it again within a single IRQ handler call, see the
statements 3a/3b and 3c above).
Fixes: f7824ded4149 ("EDAC/synopsys: Add support for version 3 of the Synopsys EDAC DDR")
Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240222181324.28242-2-fancer.lancer@gmail.com
KVM/arm64 fixes for 6.9, part #2
- Fix + test for a NULL dereference resulting from unsanitised user
input in the vgic-v2 device attribute accessors
KVM allows issuing the KVM_CHECK_EXTENSION ioctl either on the /dev/kvm
fd or the VM fd. In the first case, kvm_vm_ioctl_check_extension() is
called with kvm==NULL. Ensure we don't dereference the pointer in that
case.
Fixes: 40ebdb8e59df ("KVM: s390: Make huge pages unavailable in ucontrol VMs")
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Message-ID: <20240419160723.320910-2-jean-philippe@linaro.org>
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Unconditionally share _metadata between all forked processes, which
enables to actually catch errors which were previously ignored.
This is required for a following commit replacing vfork() with clone3()
and CLONE_VFORK (i.e. not sharing the full memory) . It should also be
useful to share _metadata to extend expectations to test process's
forks. For instance, this change identified a wrong expectation in
pidfd_setns_test.
Because this _metadata is used by the new XFAIL_ADD(), use a global
pointer initialized in TEST_F(). This is OK because only XFAIL_ADD()
use it, and XFAIL_ADD() already depends on TEST_F().
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Will Drewry <wad@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20240511171445.904356-9-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Pull drm fixes from Dave Airlie:
"This should be the last set of fixes for 6.9, i915, xe and amdgpu are
the bulk here, one of the previous nouveau fixes turned up an issue,
so reverting it, otherwise one core and a couple of meson fixes.
core:
- fix connector debugging output
i915:
- Automate CCS Mode setting during engine resets
- Fix audio time stamp programming for DP
- Fix parsing backlight BDB data
xe:
- Fix use zero-length element array
- Move more from system wq to ordered private wq
- Do not ignore return for drmm_mutex_init
amdgpu:
- DCN 3.5 fix
- MST DSC fixes
- S0i3 fix
- S4 fix
- HDP MMIO mapping fix
- Fix a regression in visible vram handling
amdkfd:
- Spatial partition fix
meson:
- dw-hdmi: power-up fixes
- dw-hdmi: add badngap setting for g12
nouveau:
- revert SG_DEBUG fix that has a side effect"
* tag 'drm-fixes-2024-05-11' of https://gitlab.freedesktop.org/drm/kernel:
Revert "drm/nouveau/firmware: Fix SG_DEBUG error with nvkm_firmware_ctor()"
drm/amdgpu: Fix comparison in amdgpu_res_cpu_visible
drm/amdkfd: don't allow mapping the MMIO HDP page with large pages
drm/xe: Use ordered WQ for G2H handler
drm/xe/guc: Check error code when initializing the CT mutex
drm/xe/ads: Use flexible-array
Revert "drm/amdkfd: Add partition id field to location_id"
dm/amd/pm: Fix problems with reboot/shutdown for some SMU 13.0.4/13.0.11 users
drm/amd/display: MST DSC check for older devices
drm/amd/display: Fix idle optimization checks for multi-display and dual eDP
drm/amd/display: Fix DSC-re-computing
drm/amd/display: Enable urgent latency adjustments for DCN35
drm/connector: Add \n to message about demoting connector force-probes
drm/i915/bios: Fix parsing backlight BDB data
drm/i915/audio: Fix audio time stamp programming for DP
drm/i915/gt: Automate CCS Mode setting during engine resets
drm/meson: dw-hdmi: add bandgap setting for g12
drm/meson: dw-hdmi: power up phy on device init
The original topology evaluation code initialized cpu_data::topo::llc_id
with the die ID initialy and then eventually overwrite it with information
gathered from a CPUID leaf.
The conversion analysis failed to spot that particular detail and omitted
this initial assignment under the assumption that each topology evaluation
path will set it up. That assumption is mostly correct, but turns out to be
wrong in case that the CPUID leaf 0x80000006 does not provide a LLC ID.
In that case, LLC ID is invalid and as a consequence the setup of the
scheduling domain CPU masks is incorrect which subsequently causes the
scheduler core to complain about it during CPU hotplug:
BUG: arch topology borken
the CLS domain not a subset of the MC domain
Cure it by reusing legacy_set_llc() and assigning the die ID if the LLC ID
is invalid after all possible parsers have been tried.
Fixes: f7fb3b2dd92c ("x86/cpu: Provide an AMD/HYGON specific topology parser")
Reported-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Link: https://lore.kernel.org/r/PUZPR04MB63168AC442C12627E827368581292@PUZPR04MB6316.apcprd04.prod.outlook.com