gcc doesn't care, but clang quite reasonably pointed out that the recent
commit e9ba16e68cce ("smpboot: Mark idle_init() as __always_inlined to
work around aggressive compiler un-inlining") did some really odd
things:

kernel/smpboot.c:50:20: warning: duplicate 'inline' declaration specifier [-Wduplicate-decl-specifier]
static inline void __always_inline idle_init(unsigned int cpu)
^

which not only has that duplicate inlining specifier, but the new
__always_inline was put in the wrong place of the function definition.

We put the storage class specifiers (ie things like "static" and
"extern") first, and the type information after that. And while the
compiler may not care, we put the inline specifier before the types.

So it should be just

static __always_inline void idle_init(unsigned int cpu)

instead.

Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull powerpc fixes from Michael Ellerman:

- Fix guest to host memory corruption in H_RTAS due to missing nargs
check.

- Fix guest triggerable host crashes due to bad handling of nested
guest TM state.

- Fix possible crashes due to incorrect reference counting in
kvm_arch_vcpu_ioctl().

- Two commits fixing some regressions in KVM transactional memory
handling introduced by the recent rework of the KVM code.

Thanks to Nicholas Piggin, Alexey Kardashevskiy, and Michael Neuling.

* tag 'powerpc-5.14-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
KVM: PPC: Book3S HV Nested: Sanitise H_ENTER_NESTED TM state
KVM: PPC: Book3S: Fix H_RTAS rets buffer overflow
KVM: PPC: Fix kvm_arch_vcpu_ioctl vcpu_load leak
KVM: PPC: Book3S: Fix CONFIG_TRANSACTIONAL_MEM=n crash
KVM: PPC: Book3S HV P9: Fix guest TM support

Pull timer fixes from Thomas Gleixner:
"A small set of timer related fixes:

- Plug a race between rearm and process tick in the posix CPU timers
code

- Make the optimization to avoid recalculation of the next timer
interrupt work correctly when there are no timers pending"

* tag 'timers-urgent-2021-07-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
timers: Fix get_next_timer_interrupt() with no timers pending
posix-cpu-timers: Fix rearm racing against process tick

The H_ENTER_NESTED hypercall is handled by the L0, and it is a request
by the L1 to switch the context of the vCPU over to that of its L2
guest, and return with an interrupt indication. The L1 is responsible
for switching some registers to guest context, and the L0 switches
others (including all the hypervisor privileged state).

If the L2 MSR has TM active, then the L1 is responsible for
recheckpointing the L2 TM state. Then the L1 exits to L0 via the
H_ENTER_NESTED hcall, and the L0 saves the TM state as part of the exit,
and then it recheckpoints the TM state as part of the nested entry and
finally HRFIDs into the L2 with TM active MSR. Not efficient, but about
the simplest approach for something that's horrendously complicated.

Problems arise if the L1 exits to the L0 with a TM state which does not
match the L2 TM state being requested. For example if the L1 is
transactional but the L2 MSR is non-transactional, or vice versa. The
L0's HRFID can take a TM Bad Thing interrupt and crash.

Fix this by disallowing H_ENTER_NESTED in TM[T] state entirely, and then
ensuring that if the L1 is suspended then the L2 must have TM active,
and if the L1 is not suspended then the L2 must not have TM active.

Fixes: 360cae313702 ("KVM: PPC: Book3S HV: Nested guest entry via hypercall")
Cc: stable@vger.kernel.org # v4.20+
Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Acked-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Pull x86 jump label fix from Thomas Gleixner:
"A single fix for jump labels to prevent the compiler from agressive
un-inlining which results in a section mismatch"

* tag 'locking-urgent-2021-07-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
jump_labels: Mark __jump_label_transform() as __always_inlined to work around aggressive compiler un-inlining

Pull dyntick fixes from Frederic Weisbecker:

- Fix a rearm race in the posix cpu timer code
- Handle get_next_timer_interrupt() correctly when no timers are pending

Link: https://lore.kernel.org/r/20210715104218.81276-1-frederic@kernel.org

The kvmppc_rtas_hcall() sets the host rtas_args.rets pointer based on
the rtas_args.nargs that was provided by the guest. That guest nargs
value is not range checked, so the guest can cause the host rets pointer
to be pointed outside the args array. The individual rtas function
handlers check the nargs and nrets values to ensure they are correct,
but if they are not, the handlers store a -3 (0xfffffffd) failure
indication in rets[0] which corrupts host memory.

Fix this by testing up front whether the guest supplied nargs and nret
would exceed the array size, and fail the hcall directly without storing
a failure indication to rets[0].

Also expand on a comment about why we kill the guest and try not to
return errors directly if we have a valid rets[0] pointer.

Fixes: 8e591cb72047 ("KVM: PPC: Book3S: Add infrastructure to implement kernel-side RTAS calls")
Cc: stable@vger.kernel.org # v3.10+
Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Pull EFI fixes from Thomas Gleixner:
"A set of EFI fixes:

- Prevent memblock and I/O reserved resources to get out of sync when
EFI memreserve is in use.

- Don't claim a non-existing table is invalid

- Don't warn when firmware memory is already reserved correctly"

* tag 'efi-urgent-2021-07-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
efi/mokvar: Reserve the table only if it is in boot services data
efi/libstub: Fix the efi_load_initrd function description
firmware/efi: Tell memblock about EFI iomem reservations
efi/tpm: Differentiate missing and invalid final event log table.

In randconfig testing, certain UBSAN and CC Kconfig combinations
with GCC 10.3.0:

CONFIG_X86_32=y

CONFIG_CC_OPTIMIZE_FOR_SIZE=y

CONFIG_UBSAN=y
# CONFIG_UBSAN_TRAP is not set
# CONFIG_UBSAN_BOUNDS is not set
CONFIG_UBSAN_SHIFT=y
# CONFIG_UBSAN_DIV_ZERO is not set
CONFIG_UBSAN_UNREACHABLE=y
CONFIG_UBSAN_BOOL=y
# CONFIG_UBSAN_ENUM is not set
# CONFIG_UBSAN_ALIGNMENT is not set
# CONFIG_UBSAN_SANITIZE_ALL is not set

... produce this build warning (and build error if
CONFIG_SECTION_MISMATCH_WARN_ONLY=y is set):

WARNING: modpost: vmlinux.o(.text+0x4c1cc): Section mismatch in reference from the function __jump_label_transform() to the function .init.text:text_poke_early()
The function __jump_label_transform() references
the function __init text_poke_early().
This is often because __jump_label_transform lacks a __init
annotation or the annotation of text_poke_early is wrong.

ERROR: modpost: Section mismatches detected.

The problem is that __jump_label_transform() gets uninlined by GCC,
despite there being only a single local scope user of the 'static inline'
function.

Mark the function __always_inline instead, to work around this compiler
bug/artifact.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

31cd0e119d50 ("timers: Recalculate next timer interrupt only when
necessary") subtly altered get_next_timer_interrupt()'s behaviour. The
function no longer consistently returns KTIME_MAX with no timers
pending.

In order to decide if there are any timers pending we check whether the
next expiry will happen NEXT_TIMER_MAX_DELTA jiffies from now.
Unfortunately, the next expiry time and the timer base clock are no
longer updated in unison. The former changes upon certain timer
operations (enqueue, expire, detach), whereas the latter keeps track of
jiffies as they move forward. Ultimately breaking the logic above.

A simplified example:

- Upon entering get_next_timer_interrupt() with:

jiffies = 1
base->clk = 0;
base->next_expiry = NEXT_TIMER_MAX_DELTA;

'base->next_expiry == base->clk + NEXT_TIMER_MAX_DELTA', the function
returns KTIME_MAX.

- 'base->clk' is updated to the jiffies value.

- The next time we enter get_next_timer_interrupt(), taking into account
no timer operations happened:

base->clk = 1;
base->next_expiry = NEXT_TIMER_MAX_DELTA;

'base->next_expiry != base->clk + NEXT_TIMER_MAX_DELTA', the function
returns a valid expire time, which is incorrect.

This ultimately might unnecessarily rearm sched's timer on nohz_full
setups, and add latency to the system[1].

So, introduce 'base->timers_pending'[2], update it every time
'base->next_expiry' changes, and use it in get_next_timer_interrupt().

[1] See tick_nohz_stop_tick().
[2] A quick pahole check on x86_64 and arm64 shows it doesn't make
'struct timer_base' any bigger.

Fixes: 31cd0e119d50 ("timers: Recalculate next timer interrupt only when necessary")
Signed-off-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>

vcpu_put is not called if the user copy fails. This can result in preempt
notifier corruption and crashes, among other issues.

Fixes: b3cebfe8c1ca ("KVM: PPC: Move vcpu_load/vcpu_put down to each ioctl case in kvm_arch_vcpu_ioctl")
Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210716024310.164448-2-npiggin@gmail.com

Pull core fix from Thomas Gleixner:
"A single update for the boot code to prevent aggressive un-inlining
which causes a section mismatch"

* tag 'core-urgent-2021-07-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
smpboot: Mark idle_init() as __always_inlined to work around aggressive compiler un-inlining