With x86_64_defconfig and the following configs, there is an orphan
section warning:

CONFIG_SMP=n
CONFIG_AMD_MEM_ENCRYPT=y
CONFIG_HYPERVISOR_GUEST=y
CONFIG_KVM=y
CONFIG_PARAVIRT=y

ld: warning: orphan section `.data..decrypted' from `arch/x86/kernel/cpu/vmware.o' being placed in section `.data..decrypted'
ld: warning: orphan section `.data..decrypted' from `arch/x86/kernel/kvm.o' being placed in section `.data..decrypted'

These sections are created with DEFINE_PER_CPU_DECRYPTED, which
ultimately turns into __PCPU_ATTRS, which in turn has a section
attribute with a value of PER_CPU_BASE_SECTION + the section name. When
CONFIG_SMP is not set, the base section is .data and that is not
currently handled in any linker script.

Add .data..decrypted to PERCPU_DECRYPTED_SECTION, which is included in
PERCPU_INPUT -> PERCPU_SECTION, which is include in the x86 linker
script when either CONFIG_X86_64 or CONFIG_SMP is unset, taking care of
the warning.

Fixes: ac26963a ("percpu: Introduce DEFINE_PER_CPU_DECRYPTED")
Link: https://github.com/ClangBuiltLinux/linux/issues/1360Reported-by: Nkernel test robot <lkp@intel.com>
Signed-off-by: NNathan Chancellor <nathan@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com> # build
Signed-off-by: NKees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210506001410.1026691-1-nathan@kernel.org

Since /dev/kmem has been removed, let's remove the xlate_dev_kmem_ptr()
leftovers.

Link: https://lkml.kernel.org/r/20210324102351.6932-3-david@redhat.comSigned-off-by: NDavid Hildenbrand <david@redhat.com>
Acked-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Palmer Dabbelt <palmerdabbelt@google.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Niklas Schnelle <schnelle@linux.ibm.com>
Cc: Pierre Morel <pmorel@linux.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Similarly to bitmap functions, users would benefit if we'll handle a case
of small-size bitmaps that fit into a single word.

While here, move the find_last_bit() declaration to bitops/find.h where
other find_*_bit() functions sit.

Link: https://lkml.kernel.org/r/20210401003153.97325-11-yury.norov@gmail.comSigned-off-by: NYury Norov <yury.norov@gmail.com>
Acked-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Cc: Alexey Klimov <aklimov@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Sterba <dsterba@suse.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Jianpeng Ma <jianpeng.ma@intel.com>
Cc: Joe Perches <joe@perches.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Stefano Brivio <sbrivio@redhat.com>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: Wolfram Sang <wsa+renesas@sang-engineering.com>
Cc: Yoshinori Sato <ysato@users.osdn.me>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Similarly to bitmap functions, find_next_*_bit() users will benefit if
we'll handle a case of bitmaps that fit into a single word inline.  In the
very best case, the compiler may replace a function call with a few
instructions.

This is the quite typical find_next_bit() user:

	unsigned int cpumask_next(int n, const struct cpumask *srcp)
	{
		/* -1 is a legal arg here. */
		if (n != -1)
			cpumask_check(n);
		return find_next_bit(cpumask_bits(srcp), nr_cpumask_bits, n + 1);
	}
	EXPORT_SYMBOL(cpumask_next);

Currently, on ARM64 the generated code looks like this:
	0000000000000000 <cpumask_next>:
	   0:   a9bf7bfd        stp     x29, x30, [sp, #-16]!
	   4:   11000402        add     w2, w0, #0x1
	   8:   aa0103e0        mov     x0, x1
	   c:   d2800401        mov     x1, #0x40                       // #64
	  10:   910003fd        mov     x29, sp
	  14:   93407c42        sxtw    x2, w2
	  18:   94000000        bl      0 <find_next_bit>
	  1c:   a8c17bfd        ldp     x29, x30, [sp], #16
	  20:   d65f03c0        ret
	  24:   d503201f        nop

After applying this patch:
	0000000000000140 <cpumask_next>:
	 140:   11000400        add     w0, w0, #0x1
	 144:   93407c00        sxtw    x0, w0
	 148:   f100fc1f        cmp     x0, #0x3f
	 14c:   54000168        b.hi    178 <cpumask_next+0x38>  // b.pmore
	 150:   f9400023        ldr     x3, [x1]
	 154:   92800001        mov     x1, #0xffffffffffffffff         // #-1
	 158:   9ac02020        lsl     x0, x1, x0
	 15c:   52800802        mov     w2, #0x40                       // #64
	 160:   8a030001        and     x1, x0, x3
	 164:   dac00020        rbit    x0, x1
	 168:   f100003f        cmp     x1, #0x0
	 16c:   dac01000        clz     x0, x0
	 170:   1a800040        csel    w0, w2, w0, eq  // eq = none
	 174:   d65f03c0        ret
	 178:   52800800        mov     w0, #0x40                       // #64
	 17c:   d65f03c0        ret

find_next_bit() call is replaced with 6 instructions.  find_next_bit()
itself is 41 instructions plus function call overhead.

Despite inlining, the scripts/bloat-o-meter report smaller .text size
after applying the series:
	add/remove: 11/9 grow/shrink: 233/176 up/down: 5780/-6768 (-988)

Link: https://lkml.kernel.org/r/20210401003153.97325-10-yury.norov@gmail.comSigned-off-by: NYury Norov <yury.norov@gmail.com>
Acked-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Cc: Alexey Klimov <aklimov@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Sterba <dsterba@suse.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Jianpeng Ma <jianpeng.ma@intel.com>
Cc: Joe Perches <joe@perches.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Stefano Brivio <sbrivio@redhat.com>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: Wolfram Sang <wsa+renesas@sang-engineering.com>
Cc: Yoshinori Sato <ysato@users.osdn.me>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

lib/find_bit.c declares five single-line wrappers for _find_next_bit().
We may turn those wrappers to inline functions.  It eliminates unneeded
function calls and opens room for compile-time optimizations.

Link: https://lkml.kernel.org/r/20210401003153.97325-8-yury.norov@gmail.comSigned-off-by: NYury Norov <yury.norov@gmail.com>
Acked-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Cc: Alexey Klimov <aklimov@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Sterba <dsterba@suse.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Jianpeng Ma <jianpeng.ma@intel.com>
Cc: Joe Perches <joe@perches.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Stefano Brivio <sbrivio@redhat.com>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: Wolfram Sang <wsa+renesas@sang-engineering.com>
Cc: Yoshinori Sato <ysato@users.osdn.me>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

find_bit would also benefit from small_const_nbits() optimizations.  The
detailed comment is provided by Rasmus Villemoes.

Link: https://lkml.kernel.org/r/20210401003153.97325-6-yury.norov@gmail.comSuggested-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: NYury Norov <yury.norov@gmail.com>
Acked-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Cc: Alexey Klimov <aklimov@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Sterba <dsterba@suse.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Jianpeng Ma <jianpeng.ma@intel.com>
Cc: Joe Perches <joe@perches.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Stefano Brivio <sbrivio@redhat.com>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: Wolfram Sang <wsa+renesas@sang-engineering.com>
Cc: Yoshinori Sato <ysato@users.osdn.me>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Correct inline documentation for `do_div', which is a function-like
macro the `n' parameter of which has the semantics of a C++ reference:
it is both read and written in the context of the caller without an
explicit dereference such as with a pointer.

In the C programming language it has no equivalent for proper functions,
in terms of which the documentation expresses the semantics of `do_div',
but substituting a pointer in documentation is misleading, and using the
C++ notation should at least raise the reader's attention and encourage
to seek explanation even if the C++ semantics is not readily understood.

While at it observe that "semantics" is an uncountable noun, so refer to
it with a singular rather than plural verb.
Signed-off-by: NMaciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: NThomas Bogendoerfer <tsbogend@alpha.franken.de>

There is not a consistent pattern for checking Hyper-V hypercall status.
Existing code uses a number of variants.  The variants work, but a consistent
pattern would improve the readability of the code, and be more conformant
to what the Hyper-V TLFS says about hypercall status.

Implemented new helper functions hv_result(), hv_result_success(), and
hv_repcomp().  Changed the places where hv_do_hypercall() and related variants
are used to use the helper functions.
Signed-off-by: NJoseph Salisbury <joseph.salisbury@microsoft.com>
Reviewed-by: NMichael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1618620183-9967-2-git-send-email-joseph.salisbury@linux.microsoft.comSigned-off-by: NWei Liu <wei.liu@kernel.org>

This patch makes no functional changes.  It simply moves hv_do_rep_hypercall()
out of arch/x86/include/asm/mshyperv.h and into asm-generic/mshyperv.h

hv_do_rep_hypercall() is architecture independent, so it makes sense that it
should be in the architecture independent mshyperv.h, not in the x86-specific
mshyperv.h.

This is done in preperation for a follow up patch which creates a consistent
pattern for checking Hyper-V hypercall status.
Signed-off-by: NJoseph Salisbury <joseph.salisbury@microsoft.com>
Reviewed-by: NMichael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1618620183-9967-1-git-send-email-joseph.salisbury@linux.microsoft.comSigned-off-by: NWei Liu <wei.liu@kernel.org>

It accidentally slipped into the #ifdef for ioremap_uc().
Signed-off-by: NHector Martin <marcan@marcan.st>
Link: https://lore.kernel.org/r/20210409052038.58925-1-marcan@marcan.st'
Signed-off-by: NArnd Bergmann <arnd@arndb.de>

This change adds support for Clang’s forward-edge Control Flow
Integrity (CFI) checking. With CONFIG_CFI_CLANG, the compiler
injects a runtime check before each indirect function call to ensure
the target is a valid function with the correct static type. This
restricts possible call targets and makes it more difficult for
an attacker to exploit bugs that allow the modification of stored
function pointers. For more details, see:

  https://clang.llvm.org/docs/ControlFlowIntegrity.html

Clang requires CONFIG_LTO_CLANG to be enabled with CFI to gain
visibility to possible call targets. Kernel modules are supported
with Clang’s cross-DSO CFI mode, which allows checking between
independently compiled components.

With CFI enabled, the compiler injects a __cfi_check() function into
the kernel and each module for validating local call targets. For
cross-module calls that cannot be validated locally, the compiler
calls the global __cfi_slowpath_diag() function, which determines
the target module and calls the correct __cfi_check() function. This
patch includes a slowpath implementation that uses __module_address()
to resolve call targets, and with CONFIG_CFI_CLANG_SHADOW enabled, a
shadow map that speeds up module look-ups by ~3x.

Clang implements indirect call checking using jump tables and
offers two methods of generating them. With canonical jump tables,
the compiler renames each address-taken function to <function>.cfi
and points the original symbol to a jump table entry, which passes
__cfi_check() validation. This isn’t compatible with stand-alone
assembly code, which the compiler doesn’t instrument, and would
result in indirect calls to assembly code to fail. Therefore, we
default to using non-canonical jump tables instead, where the compiler
generates a local jump table entry <function>.cfi_jt for each
address-taken function, and replaces all references to the function
with the address of the jump table entry.

Note that because non-canonical jump table addresses are local
to each component, they break cross-module function address
equality. Specifically, the address of a global function will be
different in each module, as it's replaced with the address of a local
jump table entry. If this address is passed to a different module,
it won’t match the address of the same function taken there. This
may break code that relies on comparing addresses passed from other
components.

CFI checking can be disabled in a function with the __nocfi attribute.
Additionally, CFI can be disabled for an entire compilation unit by
filtering out CC_FLAGS_CFI.

By default, CFI failures result in a kernel panic to stop a potential
exploit. CONFIG_CFI_PERMISSIVE enables a permissive mode, where the
kernel prints out a rate-limited warning instead, and allows execution
to continue. This option is helpful for locating type mismatches, but
should only be enabled during development.
Signed-off-by: NSami Tolvanen <samitolvanen@google.com>
Reviewed-by: NKees Cook <keescook@chromium.org>
Tested-by: NNathan Chancellor <nathan@kernel.org>
Signed-off-by: NKees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210408182843.1754385-2-samitolvanen@google.com

ARM64 currently defaults to posted MMIO (nGnRE), but some devices
require the use of non-posted MMIO (nGnRnE). Introduce a new ioremap()
variant to handle this case. ioremap_np() returns NULL on arches that
do not implement this variant.

sparc64 is the only architecture that needs to be touched directly,
because it includes neither of the generic io.h or iomap.h headers.

This adds the IORESOURCE_MEM_NONPOSTED flag, which maps to this
variant and marks a given resource as requiring non-posted mappings.
This is implemented in the resource system because it is a SoC-level
requirement, so existing drivers do not need special-case code to pick
this ioremap variant.

Then this is implemented in devres by introducing devm_ioremap_np(),
and making devm_ioremap_resource() automatically select this variant
when the resource has the IORESOURCE_MEM_NONPOSTED flag set.
Acked-by: NMarc Zyngier <maz@kernel.org>
Signed-off-by: NHector Martin <marcan@marcan.st>

Linux has support for free page reporting now (36e66c55) for
virtualized environment. On Hyper-V when virtually backed VMs are
configured, Hyper-V will advertise cold memory discard capability,
when supported. This patch adds the support to hook into the free
page reporting infrastructure and leverage the Hyper-V cold memory
discard hint hypercall to report/free these pages back to the host.
Signed-off-by: NSunil Muthuswamy <sunilmut@microsoft.com>
Tested-by: NMatheus Castello <matheus@castello.eng.br>
Reviewed-by: NMichael Kelley <mikelley@microsoft.com>
Tested-by: NNathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/SN4PR2101MB0880121FA4E2FEC67F35C1DCC0649@SN4PR2101MB0880.namprd21.prod.outlook.comSigned-off-by: NWei Liu <wei.liu@kernel.org>

Add two function prototypes for -W1 warnings generated by the
kernel test robot.
Reported-by: Nkernel test robot <lkp@intel.com>
Signed-off-by: NMichael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1615402069-39462-1-git-send-email-mikelley@microsoft.comSigned-off-by: NWei Liu <wei.liu@kernel.org>

STIMER0 interrupts are most naturally modeled as per-cpu IRQs. But
because x86/x64 doesn't have per-cpu IRQs, the core STIMER0 interrupt
handling machinery is done in code under arch/x86 and Linux IRQs are
not used. Adding support for ARM64 means adding equivalent code
using per-cpu IRQs under arch/arm64.

A better model is to treat per-cpu IRQs as the normal path (which it is
for modern architectures), and the x86/x64 path as the exception. Do this
by incorporating standard Linux per-cpu IRQ allocation into the main
SITMER0 driver code, and bypass it in the x86/x64 exception case. For
x86/x64, special case code is retained under arch/x86, but no STIMER0
interrupt handling code is needed under arch/arm64.

No functional change.
Signed-off-by: NMichael Kelley <mikelley@microsoft.com>
Acked-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/1614721102-2241-11-git-send-email-mikelley@microsoft.comSigned-off-by: NWei Liu <wei.liu@kernel.org>

VMbus interrupts are most naturally modelled as per-cpu IRQs.  But
because x86/x64 doesn't have per-cpu IRQs, the core VMbus interrupt
handling machinery is done in code under arch/x86 and Linux IRQs are
not used.  Adding support for ARM64 means adding equivalent code
using per-cpu IRQs under arch/arm64.

A better model is to treat per-cpu IRQs as the normal path (which it is
for modern architectures), and the x86/x64 path as the exception.  Do this
by incorporating standard Linux per-cpu IRQ allocation into the main VMbus
driver, and bypassing it in the x86/x64 exception case. For x86/x64,
special case code is retained under arch/x86, but no VMbus interrupt
handling code is needed under arch/arm64.

No functional change.
Signed-off-by: NMichael Kelley <mikelley@microsoft.com>
Reviewed-by: NBoqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/1614721102-2241-7-git-send-email-mikelley@microsoft.comSigned-off-by: NWei Liu <wei.liu@kernel.org>

With the new Hyper-V MSR set function, hyperv_report_panic_msg() can be
architecture neutral, so move it out from under arch/x86 and merge into
hv_kmsg_dump(). This move also avoids needing a separate implementation
under arch/arm64.

No functional change.
Signed-off-by: NMichael Kelley <mikelley@microsoft.com>
Reviewed-by: NBoqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/1614721102-2241-5-git-send-email-mikelley@microsoft.comSigned-off-by: NWei Liu <wei.liu@kernel.org>

Current code defines a separate get and set macro for each Hyper-V
synthetic MSR used by the VMbus driver. Furthermore, the get macro
can't be converted to a standard function because the second argument
is modified in place, which is somewhat bad form.

Redo this by providing a single get and a single set function that
take a parameter specifying the MSR to be operated on. Fixup usage
of the get function. Calling locations are no more complex than before,
but the code under arch/x86 and the upcoming code under arch/arm64
is significantly simplified.

Also standardize the names of Hyper-V synthetic MSRs that are
architecture neutral. But keep the old x86-specific names as aliases
that can be removed later when all references (particularly in KVM
code) have been cleaned up in a separate patch series.

No functional change.
Signed-off-by: NMichael Kelley <mikelley@microsoft.com>
Reviewed-by: NBoqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/1614721102-2241-4-git-send-email-mikelley@microsoft.comSigned-off-by: NWei Liu <wei.liu@kernel.org>

The definition of enum hv_message_type includes arch neutral and
x86/x64-specific values. Ideally there would be a way to put the
arch neutral values in an arch neutral module, and the arch
specific values in an arch specific module. But C doesn't provide
a way to extend enum types. As a compromise, move the entire
definition into an arch neutral module, to avoid duplicating the
arch neutral values for x86/x64 and for ARM64.

No functional change.
Signed-off-by: NMichael Kelley <mikelley@microsoft.com>
Reviewed-by: NBoqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/1614721102-2241-3-git-send-email-mikelley@microsoft.comSigned-off-by: NWei Liu <wei.liu@kernel.org>

The Hyper-V page allocator functions are implemented in an architecture
neutral way.  Move them into the architecture neutral VMbus module so
a separate implementation for ARM64 is not needed.

No functional change.
Signed-off-by: NMichael Kelley <mikelley@microsoft.com>
Reviewed-by: NBoqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/1614721102-2241-2-git-send-email-mikelley@microsoft.comSigned-off-by: NWei Liu <wei.liu@kernel.org>

clang produces .eh_frame sections when CONFIG_GCOV_KERNEL is enabled,
even when -fno-asynchronous-unwind-tables is in KBUILD_CFLAGS:

$ make CC=clang vmlinux
...
ld: warning: orphan section `.eh_frame' from `init/main.o' being placed in section `.eh_frame'
ld: warning: orphan section `.eh_frame' from `init/version.o' being placed in section `.eh_frame'
ld: warning: orphan section `.eh_frame' from `init/do_mounts.o' being placed in section `.eh_frame'
ld: warning: orphan section `.eh_frame' from `init/do_mounts_initrd.o' being placed in section `.eh_frame'
ld: warning: orphan section `.eh_frame' from `init/initramfs.o' being placed in section `.eh_frame'
ld: warning: orphan section `.eh_frame' from `init/calibrate.o' being placed in section `.eh_frame'
ld: warning: orphan section `.eh_frame' from `init/init_task.o' being placed in section `.eh_frame'
...

$ rg "GCOV_KERNEL|GCOV_PROFILE_ALL" .config
CONFIG_GCOV_KERNEL=y
CONFIG_ARCH_HAS_GCOV_PROFILE_ALL=y
CONFIG_GCOV_PROFILE_ALL=y

This was already handled for a couple of other options in
commit d812db78 ("vmlinux.lds.h: Avoid KASAN and KCSAN's unwanted
sections") and there is an open LLVM bug for this issue. Take advantage
of that section for this config as well so that there are no more orphan
warnings.

Link: https://bugs.llvm.org/show_bug.cgi?id=46478
Link: https://github.com/ClangBuiltLinux/linux/issues/1069Reported-by: Nkernel test robot <lkp@intel.com>
Reviewed-by: NFangrui Song <maskray@google.com>
Reviewed-by: NNick Desaulniers <ndesaulniers@google.com>
Signed-off-by: NNathan Chancellor <nathan@kernel.org>
Fixes: d812db78 ("vmlinux.lds.h: Avoid KASAN and KCSAN's unwanted sections")
Cc: stable@vger.kernel.org
Signed-off-by: NKees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210130004650.2682422-1-nathan@kernel.org

LKP caught another bunch of orphaned instrumentation symbols [0]:

mipsel-linux-ld: warning: orphan section `.data.$LPBX1' from
`init/main.o' being placed in section `.data.$LPBX1'
mipsel-linux-ld: warning: orphan section `.data.$LPBX0' from
`init/main.o' being placed in section `.data.$LPBX0'
mipsel-linux-ld: warning: orphan section `.data.$LPBX1' from
`init/do_mounts.o' being placed in section `.data.$LPBX1'
mipsel-linux-ld: warning: orphan section `.data.$LPBX0' from
`init/do_mounts.o' being placed in section `.data.$LPBX0'
mipsel-linux-ld: warning: orphan section `.data.$LPBX1' from
`init/do_mounts_initrd.o' being placed in section `.data.$LPBX1'
mipsel-linux-ld: warning: orphan section `.data.$LPBX0' from
`init/do_mounts_initrd.o' being placed in section `.data.$LPBX0'
mipsel-linux-ld: warning: orphan section `.data.$LPBX1' from
`init/initramfs.o' being placed in section `.data.$LPBX1'
mipsel-linux-ld: warning: orphan section `.data.$LPBX0' from
`init/initramfs.o' being placed in section `.data.$LPBX0'
mipsel-linux-ld: warning: orphan section `.data.$LPBX1' from
`init/calibrate.o' being placed in section `.data.$LPBX1'
mipsel-linux-ld: warning: orphan section `.data.$LPBX0' from
`init/calibrate.o' being placed in section `.data.$LPBX0'

[...]

Soften the wildcard to .data.$L* to grab these ones into .data too.

[0] https://lore.kernel.org/lkml/202102231519.lWPLPveV-lkp@intel.comReported-by: Nkernel test robot <lkp@intel.com>
Signed-off-by: NAlexander Lobakin <alobakin@pm.me>
Signed-off-by: NThomas Bogendoerfer <tsbogend@alpha.franken.de>

When exporting static_call_key; with EXPORT_STATIC_CALL*(), the module
can use static_call_update() to change the function called.  This is
not desirable in general.

Not exporting static_call_key however also disallows usage of
static_call(), since objtool needs the key to construct the
static_call_site.

Solve this by allowing objtool to create the static_call_site using
the trampoline address when it builds a module and cannot find the
static_call_key symbol. The module loader will then try and map the
trampole back to a key before it constructs the normal sites list.

Doing this requires a trampoline -> key associsation, so add another
magic section that keeps those.
Originally-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: NIngo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20210127231837.ifddpn7rhwdaepiu@treble

LKP triggered lots of LD orphan warnings [0]:

mipsel-linux-ld: warning: orphan section `.data.$Lubsan_data299' from
`init/do_mounts_rd.o' being placed in section `.data.$Lubsan_data299'
mipsel-linux-ld: warning: orphan section `.data.$Lubsan_data183' from
`init/do_mounts_rd.o' being placed in section `.data.$Lubsan_data183'
mipsel-linux-ld: warning: orphan section `.data.$Lubsan_type3' from
`init/do_mounts_rd.o' being placed in section `.data.$Lubsan_type3'
mipsel-linux-ld: warning: orphan section `.data.$Lubsan_type2' from
`init/do_mounts_rd.o' being placed in section `.data.$Lubsan_type2'
mipsel-linux-ld: warning: orphan section `.data.$Lubsan_type0' from
`init/do_mounts_rd.o' being placed in section `.data.$Lubsan_type0'

[...]

Seems like "unnamed data" isn't the only type of symbols that UBSAN
instrumentation can emit.
Catch these into .data with the wildcard as well.

[0] https://lore.kernel.org/linux-mm/202102160741.k57GCNSR-lkp@intel.com

Fixes: f41b233d ("vmlinux.lds.h: catch UBSAN's "unnamed data" into data")
Reported-by: Nkernel test robot <lkp@intel.com>
Signed-off-by: NAlexander Lobakin <alobakin@pm.me>
Signed-off-by: NThomas Bogendoerfer <tsbogend@alpha.franken.de>

We expect toolchains to produce these new debug info sections as part of
DWARF v5. Add explicit placements to prevent the linker warnings from
--orphan-section=warn.

Compilers may produce such sections with explicit -gdwarf-5, or based on
the implicit default version of DWARF when -g is used via DEBUG_INFO.
This implicit default changes over time, and has changed to DWARF v5
with GCC 11.

.debug_sup was mentioned in review, but without compilers producing it
today, let's wait to add it until it becomes necessary.

Cc: stable@vger.kernel.org
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1922707Reported-by: NChris Murphy <lists@colorremedies.com>
Suggested-by: NFangrui Song <maskray@google.com>
Reviewed-by: NNathan Chancellor <nathan@kernel.org>
Reviewed-by: NMark Wielaard <mark@klomp.org>
Tested-by: NSedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: NNick Desaulniers <ndesaulniers@google.com>
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>

powerpc was the last provider of arch_remap() and the last
user of mm-arch-hooks.h.

Since commit 526a9c4a ("powerpc/vdso: Provide vdso_remap()"),
arch_remap() hence mm-arch-hooks.h are not used anymore.

Remove them.
Signed-off-by: NChristophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: NRichard Weinberger <richard@nod.at>

include/asm-generic/qrwlock.h was trying to get arch_spin_is_locked via
asm-generic/qspinlock.h.  However, this does not work because architectures
might be using queued rwlocks but not queued spinlocks (csky), or because they
might be defining their own queued_* macros before including asm/qspinlock.h.

To fix this, ensure that asm/spinlock.h always includes qrwlock.h after
defining arch_spin_is_locked (either directly for csky, or via
asm/qspinlock.h for other architectures).  The only inclusion elsewhere
is in kernel/locking/qrwlock.c.  That one is really unnecessary because
the file is only compiled in SMP configurations (config QUEUED_RWLOCKS
depends on SMP) and in that case linux/spinlock.h already includes
asm/qrwlock.h if needed, via asm/spinlock.h.
Reported-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NWaiman Long <longman@redhat.com>
Fixes: 26128cb6 ("locking/rwlocks: Add contention detection for rwlocks")
Tested-by: NGuenter Roeck <linux@roeck-us.net>
Reviewed-by: NBen Gardon <bgardon@google.com>
[Add arch/sparc and kernel/locking parts per discussion with Waiman. - Paolo]
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Signed-off-by: NSunil Muthuswamy <sunilmut@microsoft.com>
Co-Developed-by: NSunil Muthuswamy <sunilmut@microsoft.com>
Signed-off-by: NWei Liu <wei.liu@kernel.org>
Reviewed-by: NMichael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20210203150435.27941-15-wei.liu@kernel.org

We will need to identify the device we want Microsoft Hypervisor to
manipulate.  Introduce the data structures for that purpose.

They will be used in a later patch.
Signed-off-by: NSunil Muthuswamy <sunilmut@microsoft.com>
Co-Developed-by: NSunil Muthuswamy <sunilmut@microsoft.com>
Signed-off-by: NWei Liu <wei.liu@kernel.org>
Reviewed-by: NMichael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20210203150435.27941-14-wei.liu@kernel.org

We will soon use the same structure to handle IO-APIC interrupts as
well. Introduce an enum to identify the source and a data structure for
IO-APIC RTE.

While at it, update pci-hyperv.c to use the enum.

No functional change.
Signed-off-by: NWei Liu <wei.liu@kernel.org>
Acked-by: NRob Herring <robh@kernel.org>
Reviewed-by: NMichael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20210203150435.27941-13-wei.liu@kernel.org

We will soon need to access fields inside the MSI address and MSI data
fields. Introduce hv_msi_address_register and hv_msi_data_register.

Fix up one user of hv_msi_entry in mshyperv.h.

No functional change expected.
Signed-off-by: NWei Liu <wei.liu@kernel.org>
Reviewed-by: NMichael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20210203150435.27941-12-wei.liu@kernel.org

They are used to deposit pages into Microsoft Hypervisor and bring up
logical and virtual processors.
Signed-off-by: NLillian Grassin-Drake <ligrassi@microsoft.com>
Signed-off-by: NSunil Muthuswamy <sunilmut@microsoft.com>
Signed-off-by: NNuno Das Neves <nunodasneves@linux.microsoft.com>
Co-Developed-by: NLillian Grassin-Drake <ligrassi@microsoft.com>
Co-Developed-by: NSunil Muthuswamy <sunilmut@microsoft.com>
Co-Developed-by: NNuno Das Neves <nunodasneves@linux.microsoft.com>
Signed-off-by: NWei Liu <wei.liu@kernel.org>
Reviewed-by: NMichael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20210203150435.27941-10-wei.liu@kernel.org

We will need the partition ID for executing some hypercalls later.
Signed-off-by: NLillian Grassin-Drake <ligrassi@microsoft.com>
Co-Developed-by: NSunil Muthuswamy <sunilmut@microsoft.com>
Signed-off-by: NWei Liu <wei.liu@kernel.org>
Reviewed-by: NMichael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20210203150435.27941-7-wei.liu@kernel.org

This makes the name match Hyper-V TLFS.
Signed-off-by: NWei Liu <wei.liu@kernel.org>
Reviewed-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: NPavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: NMichael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20210203150435.27941-2-wei.liu@kernel.org

If bit 22 of Group B Features is set, the guest has access to the
Isolation Configuration CPUID leaf.  On x86, the first four bits
of EAX in this leaf provide the isolation type of the partition;
we entail three isolation types: 'SNP' (hardware-based isolation),
'VBS' (software-based isolation), and 'NONE' (no isolation).
Signed-off-by: NAndrea Parri (Microsoft) <parri.andrea@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: x86@kernel.org
Cc: linux-arch@vger.kernel.org
Link: https://lore.kernel.org/r/20210201144814.2701-2-parri.andrea@gmail.comReviewed-by: NMichael Kelley <mikelley@microsoft.com>
Signed-off-by: NWei Liu <wei.liu@kernel.org>

To avoid include recursion hell move the do_softirq_own_stack() related
content into a generic asm header and include it from all places in arch/
which need the prototype.

This allows architectures to provide an inline implementation of
do_softirq_own_stack() without introducing a lot of #ifdeffery all over the
place.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NKees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210210002513.289960691@linutronix.de

arm64 references the start address of .builtin_fw (__start_builtin_fw)
with a pair of R_AARCH64_ADR_PREL_PG_HI21/R_AARCH64_LDST64_ABS_LO12_NC
relocations.  The compiler is allowed to emit the
R_AARCH64_LDST64_ABS_LO12_NC relocation because struct builtin_fw in
include/linux/firmware.h is 8-byte aligned.

The R_AARCH64_LDST64_ABS_LO12_NC relocation requires the address to be a
multiple of 8, which may not be the case if .builtin_fw is empty.
Unconditionally align .builtin_fw to fix the linker error.  32-bit
architectures could use ALIGN(4) but that would add unnecessary
complexity, so just use ALIGN(8).

Link: https://lkml.kernel.org/r/20201208054646.2913063-1-maskray@google.com
Link: https://github.com/ClangBuiltLinux/linux/issues/1204
Fixes: 5658c769 ("firmware: allow firmware files to be built into kernel image")
Signed-off-by: NFangrui Song <maskray@google.com>
Reported-by: Nkernel test robot <lkp@intel.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Reviewed-by: NNick Desaulniers <ndesaulniers@google.com>
Tested-by: NNick Desaulniers <ndesaulniers@google.com>
Tested-by: NDouglas Anderson <dianders@chromium.org>
Acked-by: NNathan Chancellor <nathan@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

EXPORT_UNUSED_SYMBOL* is not actually used anywhere.  Remove the
unused functionality as we generally just remove unused code anyway.
Reviewed-by: NMiroslav Benes <mbenes@suse.cz>
Reviewed-by: NEmil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJessica Yu <jeyu@kernel.org>

As far as I can tell this has never been used at all, and certainly
not any time recently.
Reviewed-by: NMiroslav Benes <mbenes@suse.cz>
Reviewed-by: NEmil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJessica Yu <jeyu@kernel.org>

rwlocks do not currently have any facility to detect contention
like spinlocks do. In order to allow users of rwlocks to better manage
latency, add contention detection for queued rwlocks.

CC: Ingo Molnar <mingo@redhat.com>
CC: Will Deacon <will@kernel.org>
Acked-by: NPeter Zijlstra <peterz@infradead.org>
Acked-by: NDavidlohr Bueso <dbueso@suse.de>
Acked-by: NWaiman Long <longman@redhat.com>
Acked-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NBen Gardon <bgardon@google.com>
Message-Id: <20210202185734.1680553-7-bgardon@google.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>