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

Pull dma-mapping fix from Christoph Hellwig:

- handle vmalloc addresses in dma_common_{mmap,get_sgtable} (Roman
Skakun)

* tag 'dma-mapping-5.14-1' of git://git.infradead.org/users/hch/dma-mapping:
dma-mapping: handle vmalloc addresses in dma_common_{mmap,get_sgtable}

While this function is a static inline, and is only used once in
local scope, certain Kconfig variations may cause it to be compiled
as a standalone function:

89231bf0 <idle_init>:
89231bf0: 83 05 60 d9 45 89 01 addl $0x1,0x8945d960
89231bf7: 55 push %ebp

Resulting in this build failure:

WARNING: modpost: vmlinux.o(.text.unlikely+0x7fd5): Section mismatch in reference from the function idle_init() to the function .init.text:fork_idle()
The function idle_init() references
the function __init fork_idle().
This is often because idle_init lacks a __init
annotation or the annotation of fork_idle is wrong.
ERROR: modpost: Section mismatches detected.

Certain USBSAN options x86-32 builds with CONFIG_CC_OPTIMIZE_FOR_SIZE=y
seem to be causing this.

So mark idle_init() as __always_inline to work around this compiler
bug/feature.

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

Pull cifs fixes from Steve French:
"Five cifs/smb3 fixes, including a DFS failover fix, two fallocate
fixes, and two trivial coverity cleanups"

* tag '5.14-rc2-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
cifs: fix fallocate when trying to allocate a hole.
CIFS: Clarify SMB1 code for POSIX delete file
CIFS: Clarify SMB1 code for POSIX Create
cifs: support share failover when remounting
cifs: only write 64kb at a time when fallocating a small region of a file

xen-swiotlb can use vmalloc backed addresses for dma coherent allocations
and uses the common helpers. Properly handle them to unbreak Xen on
ARM platforms.

Fixes: 1b65c4e5a9af ("swiotlb-xen: use xen_alloc/free_coherent_pages")
Signed-off-by: Roman Skakun <roman_skakun@epam.com>
Reviewed-by: Andrii Anisov <andrii_anisov@epam.com>
[hch: split the patch, renamed the helpers]
Signed-off-by: Christoph Hellwig <hch@lst.de>

No need to give up the original sd minor even with this option,
and if we did we'd also need to fix the number of minors for
this configuration to actually work.

Fixes: 7c3f828b522b0 ("block: refactor device number setup in __device_add_disk")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull RISC-V fixes from Palmer Dabbelt:

- properly set the memory size, which fixes 32-bit systems

- allow initrd to load anywhere in memory, rather that restricting it
to the first 256MiB

- fix the 'mem=' parameter on 64-bit systems to properly account for
the maximum supported memory now that the kernel is outside the
linear map

- avoid installing mappings into the last 4KiB of memory, which
conflicts with error values

- avoid the stack from being freed while it is being walked

- a handful of fixes to the new copy to/from user routines

* tag 'riscv-for-linus-5.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
riscv: __asm_copy_to-from_user: Fix: Typos in comments
riscv: __asm_copy_to-from_user: Remove unnecessary size check
riscv: __asm_copy_to-from_user: Fix: fail on RV32
riscv: __asm_copy_to-from_user: Fix: overrun copy
riscv: stacktrace: pin the task's stack in get_wchan
riscv: Make sure the kernel mapping does not overlap with IS_ERR_VALUE
riscv: Make sure the linear mapping does not use the kernel mapping
riscv: Fix memory_limit for 64-bit kernel
RISC-V: load initrd wherever it fits into memory
riscv: Fix 32-bit RISC-V boot failure

Remove the conditional checking for out_data_len and skipping the fallocate
if it is 0. This is wrong will actually change any legitimate the fallocate
where the entire region is unallocated into a no-op.

Additionally, before allocating the range, if FALLOC_FL_KEEP_SIZE is set then
we need to clamp the length of the fallocate region as to not extend the size of the file.

Fixes: 966a3cb7c7db ("cifs: improve fallocate emulation")
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

This reverts commit b7eb335e26a9c7f258c96b3962c283c379d3ede0.

It turns out that the problem with the clang -Wimplicit-fallthrough
warning is not about the kernel source code, but about clang itself, and
that the warning is unusable until clang fixes its broken ways.

In particular, when you enable this warning for clang, you not only get
warnings about implicit fallthroughs. You also get this:

warning: fallthrough annotation in unreachable code [-Wimplicit-fallthrough]

which is completely broken becasue it

(a) doesn't even tell you where the problem is (seriously: no line
numbers, no filename, no nothing).

(b) is fundamentally broken anyway, because there are perfectly valid
reasons to have a fallthrough statement even if it turns out that
it can perhaps not be reached.

In the kernel, an example of that second case is code in the scheduler:

switch (state) {
case cpuset:
if (IS_ENABLED(CONFIG_CPUSETS)) {
cpuset_cpus_allowed_fallback(p);
state = possible;
break;
}
fallthrough;
case possible:

where if CONFIG_CPUSETS is enabled you actually never hit the
fallthrough case at all. But that in no way makes the fallthrough
wrong.

So the warning is completely broken, and enabling it for clang is a very
bad idea.

In the meantime, we can keep the gcc option enabled, and make the gcc
build use

-Wimplicit-fallthrough=5

which means that we will at least continue to require a proper
fallthrough statement, and that gcc won't silently accept the magic
comment versions. Because gcc does this all correctly, and while the odd
"=5" part is kind of obscure, it's documented in [1]:

"-Wimplicit-fallthrough=5 doesn’t recognize any comments as
fallthrough comments, only attributes disable the warning"

so if clang ever fixes its bad behavior we can try enabling it there again.

Link: https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html [1]
Cc: Kees Cook <keescook@chromium.org>
Cc: Gustavo A. R. Silva <gustavoars@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Rewrite copy_huge_page() and move it into mm/util.c so it's always
available. Fixes an exposure of uninitialised memory on configurations
with HUGETLB and UFFD enabled and MIGRATION disabled.

Fixes: 8cc5fcbb5be8 ("mm, hugetlb: fix racy resv_huge_pages underflow on UFFDIO_COPY")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 71f642833284 ("ACPI: utils: Fix reference counting in
for_each_acpi_dev_match()") started doing "acpi_dev_put()" on a pointer
that was possibly NULL. That fails miserably, because that helper
inline function is not set up to handle that case.

Just make acpi_dev_put() silently accept a NULL pointer, rather than
calling down to put_device() with an invalid offset off that NULL
pointer.

Link: https://lore.kernel.org/lkml/a607c149-6bf6-0fd0-0e31-100378504da2@kernel.dk/
Reported-and-tested-by: Jens Axboe <axboe@kernel.dk>
Tested-by: Daniel Scally <djrscally@gmail.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fixing typos and grammar mistakes and using more intuitive label
name.

Signed-off-by: Akira Tsukamoto <akira.tsukamoto@gmail.com>
Fixes: ca6eaaa210de ("riscv: __asm_copy_to-from_user: Optimize unaligned memory access and pipeline stall")
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

Coverity also complains about the way we calculate the offset
(starting from the address of a 4 byte array within the
header structure rather than from the beginning of the struct
plus 4 bytes) for SMB1 CIFSPOSIXDelFile. This changeset
doesn't change the address but makes it slightly clearer.

Addresses-Coverity: 711519 ("Out of bounds write")
Signed-off-by: Steve French <stfrench@microsoft.com>