commit e10e2f58030c5c211d49042a8c2a1b93d40b2ffb upstream.

In the event that random_get_entropy() can't access a cycle counter or
similar, falling back to returning 0 is really not the best we can do.
Instead, at least calling random_get_entropy_fallback() would be
preferable, because that always needs to return _something_, even
falling back to jiffies eventually. It's not as though
random_get_entropy_fallback() is super high precision or guaranteed to
be entropic, but basically anything that's not zero all the time is
better than returning zero all the time.

This is accomplished by just including the asm-generic code like on
other architectures, which means we can get rid of the empty stub
function here.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit a3d0245c58f962ee99d4440ea0eaf45fb7f5a5cc upstream.

The commit cad6fade6e78 ("xtensa: clean up WSR*/RSR*/get_sr/set_sr")
replaced 'WSR' macro in the function xtensa_wsr with 'xtensa_set_sr',
but variable 'v' in the xtensa_set_sr body shadowed the argument 'v'
passed to it, resulting in wrong value written to debug registers.

Fix that by removing intermediate variable from the xtensa_set_sr
macro body.

Cc: stable@vger.kernel.org
Fixes: cad6fade6e78 ("xtensa: clean up WSR*/RSR*/get_sr/set_sr")
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 1c4664faa38923330d478f046dc743a00c1e2dec upstream.

Before the commit f9ce0be71d1f ("mm: Cleanup faultaround and finish_fault()
codepaths") there was a call to update_mmu_cache in alloc_set_pte that
used to invalidate TLB entry caching invalid PTE that caused a page
fault. That commit removed that call so now invalid TLB entry survives
causing repetitive page faults on the CPU that took the initial fault
until that TLB entry is occasionally evicted. This issue is spotted by
the xtensa TLB sanity checker.

Fix this issue by defining update_mmu_tlb function that flushes TLB entry
for the faulting address.

Cc: stable@vger.kernel.org # 5.12+
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Pull bitmap updates from Yury Norov:

 - introduce for_each_set_bitrange()

 - use find_first_*_bit() instead of find_next_*_bit() where possible

 - unify for_each_bit() macros

* tag 'bitmap-5.17-rc1' of git://github.com/norov/linux:
  vsprintf: rework bitmap_list_string
  lib: bitmap: add performance test for bitmap_print_to_pagebuf
  bitmap: unify find_bit operations
  mm/percpu: micro-optimize pcpu_is_populated()
  Replace for_each_*_bit_from() with for_each_*_bit() where appropriate
  find: micro-optimize for_each_{set,clear}_bit()
  include/linux: move for_each_bit() macros from bitops.h to find.h
  cpumask: replace cpumask_next_* with cpumask_first_* where appropriate
  tools: sync tools/bitmap with mother linux
  all: replace find_next{,_zero}_bit with find_first{,_zero}_bit where appropriate
  cpumask: use find_first_and_bit()
  lib: add find_first_and_bit()
  arch: remove GENERIC_FIND_FIRST_BIT entirely
  include: move find.h from asm_generic to linux
  bitops: move find_bit_*_le functions from le.h to find.h
  bitops: protect find_first_{,zero}_bit properly

find_bit API and bitmap API are closely related, but inclusion paths
are different - include/asm-generic and include/linux, correspondingly.
In the past it made a lot of troubles due to circular dependencies
and/or undefined symbols. Fix this by moving find.h under include/linux.

Signed-off-by: Yury Norov <yury.norov@gmail.com>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>

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

Naresh reported another architecture that was broken by the same typo that
was already fixed for three architectures: mips also refers to the
futex_atomic_op_inuser_local() function by the wrong name and runs into a
missing closing '}' as well.

Going through the source tree the same typo was found in the documentation
as well as in the xtensa code, both of which ended up escaping the
regression testing so far. In the case of xtensa, it appears that the
broken code path is only used when building for platforms that are not
supported by the default gcc configuration, so they are impossible to test
for with default setups.

After going through these more carefully and fixing up the typos, all
architectures have been build-tested again to ensure that this is now
complete.

Fixes: 4e0d84634445 ("futex: Fix sparc32/m68k/nds32 build regression")
Fixes: 3f2bedabb62c ("futex: Ensure futex_atomic_cmpxchg_inatomic() is present")
Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20211203080823.2938839-1-arnd@kernel.org

The printk header file includes ratelimit_types.h for its __ratelimit()
based usage. It is required for the static initializer used in
printk_ratelimited(). It uses a raw_spinlock_t and includes the
spinlock_types.h.

PREEMPT_RT substitutes spinlock_t with a rtmutex based implementation and so
its spinlock_t implmentation (provided by spinlock_rt.h) includes rtmutex.h and
atomic.h which leads to recursive includes where defines are missing.

By including only the raw_spinlock_t defines it avoids the atomic.h
related includes at this stage.

An example on powerpc:

|  CALL    scripts/atomic/check-atomics.sh
|In file included from include/linux/bug.h:5,
|                 from include/linux/page-flags.h:10,
|                 from kernel/bounds.c:10:
|arch/powerpc/include/asm/page_32.h: In function ‘clear_page’:
|arch/powerpc/include/asm/bug.h:87:4: error: implicit declaration of function â=80=98__WARNâ=80=99 [-Werror=3Dimplicit-function-declaration]
|   87 |    __WARN();    \
|      |    ^~~~~~
|arch/powerpc/include/asm/page_32.h:48:2: note: in expansion of macro ‘WARN_ONâ€=99
|   48 |  WARN_ON((unsigned long)addr & (L1_CACHE_BYTES - 1));
|      |  ^~~~~~~
|arch/powerpc/include/asm/bug.h:58:17: error: invalid application of ‘sizeofâ€=99 to incomplete type ‘struct bug_entryâ€=99
|   58 |     "i" (sizeof(struct bug_entry)), \
|      |                 ^~~~~~
|arch/powerpc/include/asm/bug.h:89:3: note: in expansion of macro ‘BUG_ENTRYâ€=99
|   89 |   BUG_ENTRY(PPC_TLNEI " %4, 0",   \
|      |   ^~~~~~~~~
|arch/powerpc/include/asm/page_32.h:48:2: note: in expansion of macro ‘WARN_ONâ€=99
|   48 |  WARN_ON((unsigned long)addr & (L1_CACHE_BYTES - 1));
|      |  ^~~~~~~
|In file included from arch/powerpc/include/asm/ptrace.h:298,
|                 from arch/powerpc/include/asm/hw_irq.h:12,
|                 from arch/powerpc/include/asm/irqflags.h:12,
|                 from include/linux/irqflags.h:16,
|                 from include/asm-generic/cmpxchg-local.h:6,
|                 from arch/powerpc/include/asm/cmpxchg.h:526,
|                 from arch/powerpc/include/asm/atomic.h:11,
|                 from include/linux/atomic.h:7,
|                 from include/linux/rwbase_rt.h:6,
|                 from include/linux/rwlock_types.h:55,
|                 from include/linux/spinlock_types.h:74,
|                 from include/linux/ratelimit_types.h:7,
|                 from include/linux/printk.h:10,
|                 from include/asm-generic/bug.h:22,
|                 from arch/powerpc/include/asm/bug.h:109,
|                 from include/linux/bug.h:5,
|                 from include/linux/page-flags.h:10,
|                 from kernel/bounds.c:10:
|include/linux/thread_info.h: In function â=80=98copy_overflowâ=80=99:
|include/linux/thread_info.h:210:2: error: implicit declaration of function â=80=98WARNâ=80=99 [-Werror=3Dimplicit-function-declaration]
|  210 |  WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
|      |  ^~~~

The WARN / BUG include pulls in printk.h and then ptrace.h expects WARN
(from bug.h) which is not yet complete. Even hw_irq.h has WARN_ON()
statements.

On POWERPC64 there are missing atomic64 defines while building 32bit
VDSO:
|  VDSO32C arch/powerpc/kernel/vdso32/vgettimeofday.o
|In file included from include/linux/atomic.h:80,
|                 from include/linux/rwbase_rt.h:6,
|                 from include/linux/rwlock_types.h:55,
|                 from include/linux/spinlock_types.h:74,
|                 from include/linux/ratelimit_types.h:7,
|                 from include/linux/printk.h:10,
|                 from include/linux/kernel.h:19,
|                 from arch/powerpc/include/asm/page.h:11,
|                 from arch/powerpc/include/asm/vdso/gettimeofday.h:5,
|                 from include/vdso/datapage.h:137,
|                 from lib/vdso/gettimeofday.c:5,
|                 from <command-line>:
|include/linux/atomic-arch-fallback.h: In function ‘arch_atomic64_incâ€=99:
|include/linux/atomic-arch-fallback.h:1447:2: error: implicit declaration of function ‘arch_atomic64_add’; did you mean ‘arch_atomic_add’? [-Werror=3Dimpl
|icit-function-declaration]
| 1447 |  arch_atomic64_add(1, v);
|      |  ^~~~~~~~~~~~~~~~~
|      |  arch_atomic_add

The generic fallback is not included, atomics itself are not used. If
kernel.h does not include printk.h then it comes later from the bug.h
include.

Allow asm/spinlock_types.h to be included from
linux/spinlock_types_raw.h.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20211129174654.668506-12-bigeasy@linutronix.de

The boot-time detection of futex_atomic_cmpxchg_inatomic() has a bug on
some 32-bit arm builds, and Thomas Gleixner suggested that setting
CONFIG_HAVE_FUTEX_CMPXCHG would avoid the problem, as it is always present
anyway.

Looking into which other architectures could do the same showed that almost
all architectures have it, the exceptions being:

 - some old 32-bit MIPS uniprocessor cores without ll/sc
 - one xtensa variant with no SMP
 - 32-bit SPARC when built for SMP

Fix MIPS And Xtensa by rearranging the generic code to let it be used
as a fallback.

For SPARC, the SMP definition just ends up turning off futex anyway, so
this can be done at Kconfig time instead. Note that sparc32 glibc requires
the CASA instruction for its mutexes anyway, which is only available when
running on SPARCv9 or LEON CPUs, but needs to be implemented in the sparc32
kernel for those.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Max Filippov <jcmvbkbc@gmail.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Rich Felker <dalias@libc.org>
Link: https://lore.kernel.org/r/20211026100432.1730393-1-arnd@kernel.org

Many architectures do not include asm-generic/cacheflush.h, so turn
the includes on their head and add linux/cacheflush.h which includes
asm/cacheflush.h.

Move the flush_dcache_folio() declaration from asm-generic/cacheflush.h
to linux/cacheflush.h and change linux/highmem.h to include
linux/cacheflush.h instead of asm/cacheflush.h so that all necessary
places will see flush_dcache_folio().

More functions should have their default implementations moved in the
future, but those are for follow-on patches.  This fixes csky, sparc and
sparc64 which were missed in the commit which added flush_dcache_folio().

Fixes: 08b0b0059bf1 ("mm: Add flush_dcache_folio()")
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>