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

It was possible to have pick_eevdf() return NULL, which then causes a
NULL-deref. This turned out to be due to entity_eligible() returning
falsely negative because of a s64 multiplcation overflow.

Specifically, reweight_eevdf() computes the vlag without considering
the limit placed upon vlag as update_entity_lag() does, and then the
scaling multiplication (remember that weight is 20bit fixed point) can
overflow. This then leads to the new vruntime being weird which then
causes the above entity_eligible() to go side-ways and claim nothing
is eligible.

Thus limit the range of vlag accordingly.

All this was quite rare, but fatal when it does happen.

Closes: https://lore.kernel.org/all/ZhuYyrh3mweP_Kd8@nz.home/
Closes: https://lore.kernel.org/all/CA+9S74ih+45M_2TPUY_mPPVDhNvyYfy1J1ftSix+KjiTVxg8nw@mail.gmail.com/
Closes: https://lore.kernel.org/lkml/202401301012.2ed95df0-oliver.sang@intel.com/
Fixes: eab03c23c2a1 ("sched/eevdf: Fix vruntime adjustment on reweight")
Reported-by: Sergei Trofimovich <slyich@gmail.com>
Reported-by: Igor Raits <igor@gooddata.com>
Reported-by: Breno Leitao <leitao@debian.org>
Reported-by: kernel test robot <oliver.sang@intel.com>
Reported-by: Yujie Liu <yujie.liu@intel.com>
Signed-off-by: Xuewen Yan <xuewen.yan@unisoc.com>
Reviewed-and-tested-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240422082238.5784-1-xuewen.yan@unisoc.com

Pull RISC-V fixes from Palmer Dabbelt:

- A fix for TASK_SIZE on rv64/NOMMU, to reflect the lack of user/kernel
separation

- A fix to avoid loading rv64/NOMMU kernel past the start of RAM

- A fix for RISCV_HWPROBE_EXT_ZVFHMIN on ilp32 to avoid signed integer
overflow in the bitmask

- The sud_test kselftest has been fixed to properly swizzle the syscall
number into the return register, which are not the same on RISC-V

- A fix for a build warning in the perf tools on rv32

- A fix for the CBO selftests, to avoid non-constants leaking into the
inline asm

- A pair of fixes for T-Head PBMT errata probing, which has been
renamed MAE by the vendor

* tag 'riscv-for-linus-6.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
RISC-V: selftests: cbo: Ensure asm operands match constraints, take 2
perf riscv: Fix the warning due to the incompatible type
riscv: T-Head: Test availability bit before enabling MAE errata
riscv: thead: Rename T-Head PBMT to MAE
selftests: sud_test: return correct emulated syscall value on RISC-V
riscv: hwprobe: fix invalid sign extension for RISCV_HWPROBE_EXT_ZVFHMIN
riscv: Fix loading 64-bit NOMMU kernels past the start of RAM
riscv: Fix TASK_SIZE on 64-bit NOMMU

Remove argument `params` from the `module` macro example, because the
macro does not currently support module parameters since it was not sent
with the initial merge.

Signed-off-by: Aswin Unnikrishnan <aswinunni01@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Cc: stable@vger.kernel.org
Fixes: 1fbde52bde73 ("rust: add `macros` crate")
Link: https://lore.kernel.org/r/20240419215015.157258-1-aswinunni01@gmail.com
[ Reworded slightly. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

The TDX guest platform takes one bit from the physical address to
indicate if the page is shared (accessible by VMM). This bit is not part
of the physical_mask and is not preserved during mprotect(). As a
result, the 'shared' bit is lost during mprotect() on shared mappings.

_COMMON_PAGE_CHG_MASK specifies which PTE bits need to be preserved
during modification. AMD includes 'sme_me_mask' in the define to
preserve the 'encrypt' bit.

To cover both Intel and AMD cases, include 'cc_mask' in
_COMMON_PAGE_CHG_MASK instead of 'sme_me_mask'.

Reported-and-tested-by: Chris Oo <cho@microsoft.com>

Fixes: 41394e33f3a0 ("x86/tdx: Extend the confidential computing API to support TDX guests")
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/20240424082035.4092071-1-kirill.shutemov%40linux.intel.com

reweight_eevdf() only keeps V unchanged inside itself. When se !=
cfs_rq->curr, it would be dequeued from rb tree first. So that V is
changed and the result is wrong. Pass the original V to reweight_eevdf()
to fix this issue.

Fixes: eab03c23c2a1 ("sched/eevdf: Fix vruntime adjustment on reweight")
Signed-off-by: Tianchen Ding <dtcccc@linux.alibaba.com>
[peterz: flip if() condition for clarity]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Abel Wu <wuyun.abel@bytedance.com>
Link: https://lkml.kernel.org/r/20240306022133.81008-3-dtcccc@linux.alibaba.com