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Linux kernel
============
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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)
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Do not allocate self->dir_path in the test process because this would
not be visible in the FIXTURE_TEARDOWN() process when relying on
fork()/clone3() instead of vfork().
This change is required for a following commit removing vfork() call to
not break the layout3_fs.* test cases.
Cc: Günther Noack <gnoack@google.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20240511171445.904356-6-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Fix a race condition when running several FIXTURE_TEARDOWN() managing
the same resource. This fixes a race condition in the Landlock file
system tests when creating or unmounting the same directory.
Using clone3() with CLONE_VFORK guarantees that the child and grandchild
test processes are sequentially scheduled. This is implemented with a
new clone3_vfork() helper replacing the fork() call.
This avoids triggering this error in __wait_for_test():
Test ended in some other way [127]
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>
Fixes: 41cca0542d7c ("selftests/harness: Fix TEST_F()'s vfork handling")
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20240511171445.904356-5-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Make sure fixture teardowns are run when test cases failed, including
when _metadata->teardown_parent is set to true.
Make sure only one fixture teardown is run per test case, handling the
case where the test child forks.
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Shengyu Li <shengyu.li.evgeny@gmail.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Fixes: 72d7cb5c190b ("selftests/harness: Prevent infinite loop due to Assert in FIXTURE_TEARDOWN")
Fixes: 0710a1a73fb4 ("selftests/harness: Merge TEST_F_FORK() into TEST_F()")
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20240511171445.904356-4-mic@digikod.net
Rule: add
Link: https://lore.kernel.org/stable/20240506165518.474504-4-mic%40digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
According to the test environment, the mount point of the test's working
directory may be shared or not, which changes the visibility of the
nested "tmp" mount point for the test's parent process calling
umount("tmp").
This was spotted while running tests in containers [1], where mount
points are private.
Cc: Günther Noack <gnoack@google.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Link: https://github.com/landlock-lsm/landlock-test-tools/pull/4 [1]
Fixes: 41cca0542d7c ("selftests/harness: Fix TEST_F()'s vfork handling")
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20240511171445.904356-3-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Required by switch_timens() to open /proc/self/ns/time_for_children.
CONFIG_GENERIC_VDSO_TIME_NS is not available on UML, so pidfd_setns_test
cannot be run successfully on this architecture.
Cc: Shuah Khan <skhan@linuxfoundation.org>
Fixes: 2b40c5db73e2 ("selftests/pidfd: add pidfd setns tests")
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20240511171445.904356-2-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Pull scheduler fixes from Ingo Molnar:
- Fix EEVDF corner cases
- Fix two nohz_full= related bugs that can cause boot crashes
and warnings
* tag 'sched-urgent-2024-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/isolation: Fix boot crash when maxcpus < first housekeeping CPU
sched/isolation: Prevent boot crash when the boot CPU is nohz_full
sched/eevdf: Prevent vlag from going out of bounds in reweight_eevdf()
sched/eevdf: Fix miscalculation in reweight_entity() when se is not curr
sched/eevdf: Always update V if se->on_rq when reweighting
Pull x86 fixes from Ingo Molnar:
- Make the CPU_MITIGATIONS=n interaction with conflicting
mitigation-enabling boot parameters a bit saner.
- Re-enable CPU mitigations by default on non-x86
- Fix TDX shared bit propagation on mprotect()
- Fix potential show_regs() system hang when PKE initialization
is not fully finished yet.
- Add the 0x10-0x1f model IDs to the Zen5 range
- Harden #VC instruction emulation some more
* tag 'x86-urgent-2024-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
cpu: Ignore "mitigations" kernel parameter if CPU_MITIGATIONS=n
cpu: Re-enable CPU mitigations by default for !X86 architectures
x86/tdx: Preserve shared bit on mprotect()
x86/cpu: Fix check for RDPKRU in __show_regs()
x86/CPU/AMD: Add models 0x10-0x1f to the Zen5 range
x86/sev: Check for MWAITX and MONITORX opcodes in the #VC handler
housekeeping_setup() checks cpumask_intersects(present, online) to ensure
that the kernel will have at least one housekeeping CPU after smp_init(),
but this doesn't work if the maxcpus= kernel parameter limits the number of
processors available after bootup.
For example, a kernel with "maxcpus=2 nohz_full=0-2" parameters crashes at
boot time on a virtual machine with 4 CPUs.
Change housekeeping_setup() to use cpumask_first_and() and check that the
returned CPU number is valid and less than setup_max_cpus.
Another corner case is "nohz_full=0" on a machine with a single CPU or with
the maxcpus=1 kernel argument. In this case non_housekeeping_mask is empty
and tick_nohz_full_setup() makes no sense. And indeed, the kernel hits the
WARN_ON(tick_nohz_full_running) in tick_sched_do_timer().
And how should the kernel interpret the "nohz_full=" parameter? It should
be silently ignored, but currently cpulist_parse() happily returns the
empty cpumask and this leads to the same problem.
Change housekeeping_setup() to check cpumask_empty(non_housekeeping_mask)
and do nothing in this case.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Phil Auld <pauld@redhat.com>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20240413141746.GA10008@redhat.com
Pull irq fix from Ingo Molnar:
"Fix a double free bug in the init error path of the GICv3 irqchip
driver"
* tag 'irq-urgent-2024-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/gic-v3-its: Prevent double free on error
Explicitly disallow enabling mitigations at runtime for kernels that were
built with CONFIG_CPU_MITIGATIONS=n, as some architectures may omit code
entirely if mitigations are disabled at compile time.
E.g. on x86, a large pile of Kconfigs are buried behind CPU_MITIGATIONS,
and trying to provide sane behavior for retroactively enabling mitigations
is extremely difficult, bordering on impossible. E.g. page table isolation
and call depth tracking require build-time support, BHI mitigations will
still be off without additional kernel parameters, etc.
[ bp: Touchups. ]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240420000556.2645001-3-seanjc@google.com
Documentation/timers/no_hz.rst states that the "nohz_full=" mask must not
include the boot CPU, which is no longer true after:
08ae95f4fd3b ("nohz_full: Allow the boot CPU to be nohz_full").
However after:
aae17ebb53cd ("workqueue: Avoid using isolated cpus' timers on queue_delayed_work")
the kernel will crash at boot time in this case; housekeeping_any_cpu()
returns an invalid CPU number until smp_init() brings the first
housekeeping CPU up.
Change housekeeping_any_cpu() to check the result of cpumask_any_and() and
return smp_processor_id() in this case.
This is just the simple and backportable workaround which fixes the
symptom, but smp_processor_id() at boot time should be safe at least for
type == HK_TYPE_TIMER, this more or less matches the tick_do_timer_boot_cpu
logic.
There is no worry about cpu_down(); tick_nohz_cpu_down() will not allow to
offline tick_do_timer_cpu (the 1st online housekeeping CPU).
Fixes: aae17ebb53cd ("workqueue: Avoid using isolated cpus' timers on queue_delayed_work")
Reported-by: Chris von Recklinghausen <crecklin@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Phil Auld <pauld@redhat.com>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20240411143905.GA19288@redhat.com
Closes: https://lore.kernel.org/all/20240402105847.GA24832@redhat.com/
Pull Rust fixes from Miguel Ojeda:
- Soundness: make internal functions generated by the 'module!' macro
inaccessible, do not implement 'Zeroable' for 'Infallible' and
require 'Send' for the 'Module' trait.
- Build: avoid errors with "empty" files and workaround 'rustdoc' ICE.
- Kconfig: depend on '!CFI_CLANG' and avoid selecting 'CONSTRUCTORS'.
- Code docs: remove non-existing key from 'module!' macro example.
- Docs: trivial rendering fix in arch table.
* tag 'rust-fixes-6.9' of https://github.com/Rust-for-Linux/linux:
rust: remove `params` from `module` macro example
kbuild: rust: force `alloc` extern to allow "empty" Rust files
kbuild: rust: remove unneeded `@rustc_cfg` to avoid ICE
rust: kernel: require `Send` for `Module` implementations
rust: phy: implement `Send` for `Registration`
rust: make mutually exclusive with CFI_CLANG
rust: macros: fix soundness issue in `module!` macro
rust: init: remove impl Zeroable for Infallible
docs: rust: fix improper rendering in Arch Support page
rust: don't select CONSTRUCTORS
The error handling path in its_vpe_irq_domain_alloc() causes a double free
when its_vpe_init() fails after successfully allocating at least one
interrupt. This happens because its_vpe_irq_domain_free() frees the
interrupts along with the area bitmap and the vprop_page and
its_vpe_irq_domain_alloc() subsequently frees the area bitmap and the
vprop_page again.
Fix this by unconditionally invoking its_vpe_irq_domain_free() which
handles all cases correctly and by removing the bitmap/vprop_page freeing
from its_vpe_irq_domain_alloc().
[ tglx: Massaged change log ]
Fixes: 7d75bbb4bc1a ("irqchip/gic-v3-its: Add VPE irq domain allocation/teardown")
Signed-off-by: Guanrui Huang <guanrui.huang@linux.alibaba.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240418061053.96803-2-guanrui.huang@linux.alibaba.com
Rename x86's to CPU_MITIGATIONS, define it in generic code, and force it
on for all architectures exception x86. A recent commit to turn
mitigations off by default if SPECULATION_MITIGATIONS=n kinda sorta
missed that "cpu_mitigations" is completely generic, whereas
SPECULATION_MITIGATIONS is x86-specific.
Rename x86's SPECULATIVE_MITIGATIONS instead of keeping both and have it
select CPU_MITIGATIONS, as having two configs for the same thing is
unnecessary and confusing. This will also allow x86 to use the knob to
manage mitigations that aren't strictly related to speculative
execution.
Use another Kconfig to communicate to common code that CPU_MITIGATIONS
is already defined instead of having x86's menu depend on the common
CPU_MITIGATIONS. This allows keeping a single point of contact for all
of x86's mitigations, and it's not clear that other architectures *want*
to allow disabling mitigations at compile-time.
Fixes: f337a6a21e2f ("x86/cpu: Actually turn off mitigations by default for SPECULATION_MITIGATIONS=n")
Closes: https://lkml.kernel.org/r/20240413115324.53303a68%40canb.auug.org.au
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240420000556.2645001-2-seanjc@google.com
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