The if ... else inside the for-loop is unneeded because one empty
line is placed after printing the last element of deps_config.

Currently, all errors in conf_write_dep() are ignored. Add proper
error checks.

Rename it to conf_write_autoconf_cmd(), which is more intuitive.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

This function does similar for auto.conf and autoconf.h

Create __conf_write_autoconf() helper to factor out the common code.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

For consistency with conf_get_autoconfig_name()

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Now that sym_escape_string_value() is only used in confdata.c
it can be a 'static' function.

Rename it escape_string_value() because it is agnostic about
(struct sym *).

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

We can reuse __print_symbol() helper to print symbols for listnewconfig.
Only the difference is the format for "n" symbols.

This prints "CONFIG_FOO=n" instead of "# CONFIG_FOO is not set".

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

I do not think 'struct conf_printer' is so useful.

Add simple functions, print_symbol_for_*() to write out one symbol.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

All the call sites of conf_write_heading() pass NULL to the third
argument, and it is not used in the function.

Also, the print_comment hooks are doing much more complex than
needed.

Rewrite the code.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

sym_escape_string_value() returns a malloc'ed memory, but as
(const char *). So, it must be casted to (void *) when it is free'd.
This is odd.

The return type of sym_escape_string_value() should be (char *).

I exploited that free(NULL) has no effect.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

In Kconfig, like Python, you can enclose a string by double-quotes or
single-quotes. So, both "foo" and 'foo' are allowed.

The variable, "str", is used to remember whether the string started with
a double-quote or a single-quote because open/closing quotation marks
must match.

The name "str" is too generic to understand the intent. Rename it to
"open_quote", which is easier to understand. The type should be 'char'.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Boris Kolpackov <boris@codesynthesis.com>

The variables, "ts" and "i", are used locally in the action of
the [ \t]+ pattern in the <HELP> start state.

Define them where they are used.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

When one searches for a main menu item, links aren't created for it like
with the rest of the symbols.

This happens because we trace the item until we get to the rootmenu, but
we don't include it in the path of the item. The rationale was probably
that we don't want to show the main menu in the path of all items,
because it is redundant.

However, when an item has only the rootmenu in its path it should be
included, because this way the user can jump to its location.

Add a 'Main menu' entry in the 'Location:' section for the kconfig
items.

This makes the 'if (i > 0)' superfluous because each item with prompt
will have at least one menu in its path.

Signed-off-by: Ariel Marcovitch <arielmarcovitch@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

For CONFIG_LTO_CLANG=y, the objtool processing is not possible at the
compilation, hence postponed by the link time.

Reuse $(cmd_objtool) for CONFIG_LTO_CLANG=y by defining objtool-enabled
properly.

For CONFIG_LTO_CLANG=y:

  objtool-enabled is off for %.o compilation
  objtool-enabled is on  for %.lto link

For CONFIG_LTO_CLANG=n:

  objtool-enabled is on for %.o compilation
      (but, it depends on OBJECT_FILE_NON_STANDARD)

Set part-of-module := y for %.lto.o to avoid repeating --module.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>

Redo commit 8852c552

 ("kbuild: Fix objtool dependency for
'OBJECT_FILES_NON_STANDARD_<obj> := n'") to add the objtool
dependency in a cleaner way.

Using .SECONDEXPANSION ends up with unreadable code due to escaped
dollars. Also, it is not efficient because the second half of
Makefile.build is parsed twice every time.

Append the objtool dependency to the *.cmd files at the build time.

This is what fixdep and gen_ksymdeps.sh already do. So, following the
same pattern seems a natural solution.

This allows us to drop $$(objtool_dep) entirely.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>

The OBJECT_FILES_NON_STANDARD check is quite long.

Factor it out into a new macro, objtool-enabled, to not repeat it.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>

objtool_dep includes include/config/{ORC_UNWINDER,STACK_VALIDATION}
so that all the objects are rebuilt when CONFIG_ORC_UNWINDER or
CONFIG_STACK_VALIDATION is toggled.

BTW, the correct option name is not CONFIG_ORC_UNWINDER, but
CONFIG_UNWINDER_ORC. Commit 11af8474

 ("x86/unwind: Rename
unwinder config options to 'CONFIG_UNWINDER_*'") missed to
adjust this part. So, this dependency has been broken for a
long time.

As you can see in 'objtool_args', there are more CONFIG options
that affect the objtool command line.

Adding more and more include/config/* is ugly and unmaintainable.

Another issue is that non-standard objects are needlessly rebuilt.
Objects specified as OBJECT_FILES_NON_STANDARD is not processed by
objtool, but they are rebuilt anyway when CONFIG_STACK_VALIDATION
is toggled. This is not a big deal, but better to fix.

A cleaner and more precise fix is to include the objtool command in
*.cmd files so any command change is naturally detected by if_change.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>

Rename __objtool_obj to objtool, and move it out of the
'ifndef CONFIG_LTO_CLANG' conditional, so it can be used for
cmd_cc_lto_link_modules as well.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>

Commit b1a1a1a0 ("kbuild: lto: postpone objtool") moved objtool_args
to Makefile.lib, so the arguments can be used in Makefile.modfinal as
well as Makefile.build.

With commit 850ded46

 ("kbuild: Fix TRIM_UNUSED_KSYMS with
LTO_CLANG"), module LTO linking came back to scripts/Makefile.build
again.

So, there is no more reason to keep objtool_args in a separate file.

Get it back to the original place, close to the objtool command.

Remove the stale comment too.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>

Further isolate kernel from userspace, prevent accidental inclusion of
undesireable headers, mainly float.h and stdatomic.h.

nds32 keeps -isystem globally due to intrinsics used in entrenched header.

-isystem is selectively reenabled for some files, again, for intrinsics.

Compile tested on:

hexagon-defconfig hexagon-allmodconfig
alpha-allmodconfig alpha-allnoconfig alpha-defconfig arm64-allmodconfig
arm64-allnoconfig arm64-defconfig arm-am200epdkit arm-aspeed_g4
arm-aspeed_g5 arm-assabet arm-at91_dt arm-axm55xx arm-badge4 arm-bcm2835
arm-cerfcube arm-clps711x arm-cm_x300 arm-cns3420vb arm-colibri_pxa270
arm-colibri_pxa300 arm-collie arm-corgi arm-davinci_all arm-dove
arm-ep93xx arm-eseries_pxa arm-exynos arm-ezx arm-footbridge arm-gemini
arm-h3600 arm-h5000 arm-hackkit arm-hisi arm-imote2 arm-imx_v4_v5
arm-imx_v6_v7 arm-integrator arm-iop32x arm-ixp4xx arm-jornada720
arm-keystone arm-lart arm-lpc18xx arm-lpc32xx arm-lpd270 arm-lubbock
arm-magician arm-mai...

Currently, the install target in arch/nios2/Makefile descends into
arch/nios2/boot/Makefile to invoke the shell script, but it is no
good reason to do so.

arch/nios2/Makefile can run the shell script directly.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Nathan Chancellor reports that the recent change to pci_iounmap in
commit 9caea000 ("parisc: Declare pci_iounmap() parisc version only
when CONFIG_PCI enabled") causes build errors on arm64.

It took me about two hours to convince myself that I think I know what
the logic of that mess of #ifdef's in the <asm-generic/io.h> header file
really aim to do, and rewrite it to be easier to follow.

Famous last words.

Anyway, the code has now been lifted from that grotty header file into
lib/pci_iomap.c, and has fairly extensive comments about what the logic
is.  It also avoids indirecting through another confusing (and badly
named) helper function that has other preprocessor config conditionals.

Let's see what odd architecture did something else strange in this area
to break things.  But my arm64 cross build is clean.

Fixes: 9caea000

 ("parisc: Declare pci_iounmap() parisc version only when CONFIG_PCI enabled")
Reported-by: Nathan Chancellor <nathan@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Ulrich Teichert <krypton@ulrich-teichert.org>
Cc: James Bottomley <James.Bottomley@hansenpartnership.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull x86 fixes from Borislav Petkov:

 - Prevent a infinite loop in the MCE recovery on return to user space,
   which was caused by a second MCE queueing work for the same page and
   thereby creating a circular work list.

 - Make kern_addr_valid() handle existing PMD entries, which are marked
   not present in the higher level page table, correctly instead of
   blindly dereferencing them.

 - Pass a valid address to sanitize_phys(). This was caused by the
   mixture of inclusive and exclusive ranges. memtype_reserve() expect
   'end' being exclusive, but sanitize_phys() wants it inclusive. This
   worked so far, but with end being the end of the physical address
   space the fail is exposed.

 - Increase the maximum supported GPIO numbers for 64bit. Newer SoCs
   exceed the previous maximum.

* tag 'x86_urgent_for_v5.15_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mce: Avoid infinite loop for copy from user recovery
  x86/mm: Fix kern_addr_valid() to cope with existing but not present entries
  x86/platform: Increase maximum GPIO number for X86_64
  x86/pat: Pass valid address to sanitize_phys()

Pull perf event fix from Thomas Gleixner:
 "A single fix for the perf core where a value read with READ_ONCE() was
  checked and then reread which makes all the checks invalid. Reuse the
  already read value instead"

* tag 'perf-urgent-2021-09-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  events: Reuse value read using READ_ONCE instead of re-reading it

Pull locking fixes from Thomas Gleixner:
 "A set of updates for the RT specific reader/writer locking base code:

   - Make the fast path reader ordering guarantees correct.

   - Code reshuffling to make the fix simpler"

[ This plays ugly games with atomic_add_return_release() because we
  don't have a plain atomic_add_release(), and should really be cleaned
  up, I think    - Linus ]

* tag 'locking-urgent-2021-09-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/rwbase: Take care of ordering guarantee for fastpath reader
  locking/rwbase: Extract __rwbase_write_trylock()
  locking/rwbase: Properly match set_and_save_state() to restore_state()

Pull powerpc fixes from Michael Ellerman:

 - Fix crashes when scv (System Call Vectored) is used to make a syscall
   when a transaction is active, on Power9 or later.

 - Fix bad interactions between rfscv (Return-from scv) and Power9
   fake-suspend mode.

 - Fix crashes when handling machine checks in LPARs using the Hash MMU.

 - Partly revert a recent change to our XICS interrupt controller code,
   which broke the recently added Microwatt support.

Thanks to Cédric Le Goater, Eirik Fuller, Ganesh Goudar, Gustavo Romero,
Joel Stanley, Nicholas Piggin.

* tag 'powerpc-5.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/xics: Set the IRQ chip data for the ICS native backend
  powerpc/mce: Fix access error in mce handler
  KVM: PPC: Book3S HV: Tolerate treclaim. in fake-suspend mode changing registers
  powerpc/64s: system call rfscv workaround for TM bugs
  selftests/powerpc: Add scv versions of the basic TM syscall tests
  powerpc/64s: system call scv tabort fix for corrupt irq soft-mask state

Merge tag 'kbuild-fixes-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

 - Fix bugs in checkkconfigsymbols.py

 - Fix missing sys import in gen_compile_commands.py

 - Fix missing FORCE warning for ARCH=sh builds

 - Fix -Wignored-optimization-argument warnings for Clang builds

 - Turn -Wignored-optimization-argument into an error in order to stop
   building instead of sprinkling warnings

* tag 'kbuild-fixes-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: Add -Werror=ignored-optimization-argument to CLANG_FLAGS
  x86/build: Do not add -falign flags unconditionally for clang
  kbuild: Fix comment typo in scripts/Makefile.modpost
  sh: Add missing FORCE prerequisites in Makefile
  gen_compile_commands: fix missing 'sys' package
  checkkconfigsymbols.py: Remove skipping of help lines in parse_kconfig_file
  checkkconfigsymbols.py: Forbid passing 'HEAD' to --commit

Merge tag 'perf-tools-fixes-for-v5.15-2021-09-18' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux

Pull perf tools fixes from Arnaldo Carvalho de Melo:

 - Fix ip display in 'perf script' when output type != attr->type.

 - Ignore deprecation warning when using libbpf'sg btf__get_from_id(),
   fixing the build with libbpf v0.6+.

 - Make use of FD() robust in libperf, fixing a segfault with 'perf stat
   --iostat list'.

 - Initialize addr_location:srcline pointer to NULL when resolving
   callchain addresses.

 - Fix fused instruction logic for assembly functions in 'perf
   annotate'.

* tag 'perf-tools-fixes-for-v5.15-2021-09-18' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux:
  perf bpf: Ignore deprecation warning when using libbpf's btf__get_from_id()
  libperf evsel: Make use of FD robust.
  perf machine: Initialize srcline string member in add_location struct
  perf script: Fix ip display when type != attr->type
  perf annotate: Fix fused instr logic for assembly functions

The old dmascc driver depends on the legacy ISA_DMA_API, and blindly
just casts the kernel virtual address to 'int' for set_dma_addr().

That works only incidentally, and because the high bits of the address
will be ignored anyway. And on 64-bit architectures it causes warnings.

Admittedly, 64-bit architectures with ISA are basically dead - I think
the only example of this is alpha, and nobody would ever use the dmascc
driver there.  But hey, the fix is easy enough, the end result is
cleaner, and it's yet another configuration that now builds without
warnings.

If somebody actually uses this driver on an alpha and this fixes it for
you, please email me.  Because that is just incredibly bizarre.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

With the previous commit (9caea000

: "parisc: Declare pci_iounmap()
parisc version only when CONFIG_PCI enabled") we can now enable
GENERIC_PCI_IOMAP unconditionally on alpha, and if PCI is not enabled we
will just get the nice empty helper functions that allow mixed-bus
drivers to build.

Example driver: the old 3com/3c59x.c driver works with either the PCI or
the EISA version of the 3x59x card, but wouldn't build in an EISA-only
configuration because of missing pci_iomap() and pci_iounmap() dummy
wrappers.

Most of the other PCI infrastructure just becomes empty wrappers even
without GENERIC_PCI_IOMAP, and it's not obvious that the pci_iomap
functionality shouldn't do the same, but this works.

Cc: Ulrich Teichert <krypton@ulrich-teichert.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Linus noticed odd declaration rules for pci_iounmap() in iomap.h and
pci_iomap.h, where it dependend on either NO_GENERIC_PCI_IOPORT_MAP or
GENERIC_IOMAP when CONFIG_PCI was disabled.

Testing on parisc seems to indicate that we need pci_iounmap() only when
CONFIG_PCI is enabled, so the declaration of pci_iounmap() can be moved
cleanly into pci_iomap.h in sync with the declarations of pci_iomap().

Link: https://lore.kernel.org/all/CAHk-=wjRrh98pZoQ+AzfWmsTZacWxTJKXZ9eKU2X_0+jM=O8nw@mail.gmail.com/


Signed-off-by: Helge Deller <deller@gmx.de>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Fixes: 97a29d59

 ("[PARISC] fix compile break caused by iomap: make IOPORT/PCI mapping functions conditional")
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Ulrich Teichert <krypton@ulrich-teichert.org>
Cc: James Bottomley <James.Bottomley@hansenpartnership.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This reverts commit 27da370e.

Sudip Mukherjee reports that this broke pulseaudio with a NULL pointer
dereference in vc4_hdmi_audio_prepare(), bisected it to this commit, and
confirmed that a revert fixed the problem.

Revert the problematic commit until fixed.

Link: https://lore.kernel.org/all/CADVatmPB9-oKd=ypvj25UYysVo6EZhQ6bCM7EvztQBMyiZfAyw@mail.gmail.com/
Link: https://lore.kernel.org/all/CADVatmN5EpRshGEPS_JozbFQRXg5w_8LFB3OMP1Ai-ghxd3w4g@mail.gmail.com/


Reported-and-tested-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Cc: Maxime Ripard <maxime@cerno.tech>
Cc: Emma Anholt <emma@anholt.net>
Cc: Dave Airlie <airlied@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This reverts commits

  9984d666 ("drm/vc4: hdmi: Make sure the controller is powered in detect")
  411efa18 ("drm/vc4: hdmi: Move the HSM clock enable to runtime_pm")

as Michael Stapelberg reports that the new runtime PM changes cause his
Raspberry Pi 3 to hang on boot, probably due to interactions with other
changes in the DRM tree (because a bisect points to the merge in commit
e058a84b: "Merge tag 'drm-next-2021-07-01' of git://.../drm").

Revert these two commits until it's been resolved.

Link: https://lore.kernel.org/all/871r5mp7h2.fsf@midna.i-did-not-set--mail-host-address--so-tickle-me/


Reported-and-tested-by: Michael Stapelberg <michael@stapelberg.ch>
Cc: Maxime Ripard <maxime@cerno.tech>
Cc: Dave Stevenson <dave.stevenson@raspberrypi.com>
Cc: Dave Airlie <airlied@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Similar to commit 589834b3

 ("kbuild: Add
-Werror=unknown-warning-option to CLANG_FLAGS").

Clang ignores certain GCC flags that it has not implemented, only
emitting a warning:

$ echo | clang -fsyntax-only -falign-jumps -x c -
clang-14: warning: optimization flag '-falign-jumps' is not supported
[-Wignored-optimization-argument]

When one of these flags gets added to KBUILD_CFLAGS unconditionally, all
subsequent cc-{disable-warning,option} calls fail because -Werror was
added to these invocations to turn the above warning and the equivalent
-W flag warning into errors.

To catch the presence of these flags earlier, turn
-Wignored-optimization-argument into an error so that the flags can
either be implemented or ignored via cc-option and there are no more
weird errors.

Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

clang does not support -falign-jumps and only recently gained support
for -falign-loops. When one of the configuration options that adds these
flags is enabled, clang warns and all cc-{disable-warning,option} that
follow fail because -Werror gets added to test for the presence of this
warning:

clang-14: warning: optimization flag '-falign-jumps=0' is not supported
[-Wignored-optimization-argument]

To resolve this, add a couple of cc-option calls when building with
clang; gcc has supported these options since 3.2 so there is no point in
testing for their support. -falign-functions was implemented in clang-7,
-falign-loops was implemented in clang-14, and -falign-jumps has not
been implemented yet.

Link: https://lore.kernel.org/r/YSQE2f5teuvKLkON@Ryzen-9-3900X.localdomain/
Link: https://lore.kernel.org/r/20210824022640.2170859-2-nathan@kernel.org/


Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Change comment "create one <module>.mod.c file pr. module"
to "create one <module>.mod.c file per module"

Signed-off-by: Ramji Jiyani <ramjiyani@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

make:

    arch/sh/boot/Makefile:87: FORCE prerequisite is missing

Add the missing FORCE prerequisites for all build targets identified by
"make help".

Fixes: e1f86d7b

 ("kbuild: warn if FORCE is missing for if_changed(_dep,_rule) and filechk")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

We need to import the 'sys' package since the script has called
sys.exit() method.

Fixes: 6ad7cbc0

 ("Makefile: Add clang-tidy and static analyzer support to makefile")
Signed-off-by: Kortan <kortanzh@gmail.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

When parsing Kconfig files to find symbol definitions and references,
lines after a 'help' line are skipped until a new config definition
starts.

However, Kconfig statements can actually be after a help section, as
long as these have shallower indentation. These are skipped by the
parser.

This means that symbols referenced in this kind of statements are
ignored by this function and thus are not considered undefined
references in case the symbol is not defined.

Remove the 'skip' logic entirely, as it is not needed if we just use the
STMT regex to find the end of help lines.

However, this means that keywords that appear as part of the help
message (i.e. with the same indentation as the help lines) it will be
considered as a reference/definition. This can happen now as well, but
only with REGEX_KCONFIG_DEF lines. Also, the keyword must have a SYMBOL
after it, which probably means that someone referenced a config in the
help so it...

As opposed to the --diff option, --commit can get ref names instead of
commit hashes.

When using the --commit option, the script resets the working directory
to the commit before the given ref, by adding '~' to the end of the ref.

However, the 'HEAD' ref is relative, and so when the working directory
is reset to 'HEAD~', 'HEAD' points to what was 'HEAD~'. Then when the
script resets to 'HEAD' it actually stays in the same commit. In this
case, the script won't report any cases because there is no diff between
the cases of the two refs.

Prevent the user from using HEAD refs.

A better solution might be to resolve the refs before doing the
reset, but for now just disallow such refs.

Signed-off-by: Ariel Marcovitch <arielmarcovitch@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

We already had the implementation for __udiv_qrnnd (unsigned divide for
multi-precision arithmetic) as part of the alpha math emulation code.

But you can disable the math emulation code - even if you shouldn't -
and then the MPI code that actually wants this functionality (and is
needed by various crypto functions) will fail to build.

So move the extended-precision divide code to be a regular library
function, just like all the regular division code is.  That way ie is
available regardless of math-emulation.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>