If directories are passed to gen_compile_commands.py, os.walk() traverses
all the subdirectories to search for .cmd files, but we know some of them
are not worth traversing.

Use the 'topdown' parameter of os.walk to prune them.

Documentation about the 'topdown' option of os.walk:
  When topdown is True, the caller can modify the dirnames list
  in-place (perhaps using del or slice assignment), and walk() will
  only recurse into the subdirectories whose names remain in dirnames;
  this can be used to prune the search, impose a specific order of
  visiting, or even to inform walk() about directories the caller
  creates or renames before it resumes walk() again. Modifying
  dirnames when topdown is False has no effect on the behavior of
  the walk, because in bottom-up mode the directories in dirnames
  are generated before dirpath itself is generated.

This commit prunes four directories, .git, Documentation, include, and
tools.

The first three do not contain any C files, so skipping them makes this
script work slightly faster. My main motivation is the last one, tools/
directory.

Commit 6ca4c6d2 ("gen_compile_commands: do not support .cmd files
under tools/ directory") stopped supporting the tools/ directory.
The current code no longer picks up .cmd files from the tools/
directory.

If you run:

  ./scripts/clang-tools/gen_compile_commands.py --log_level=INFO

then, you will see several "File ... not found" log messages.

This is expected, and I do not want to support the tools/ directory.
However, without an explicit comment "do not support tools/", somebody
might try to get it back. Clarify this.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Nathan Chancellor <nathan@kernel.org>

Instead of storing the version in a single integer and having various
kernel (and userspace) code how it's constructed, export individual
(major, patchlevel, sublevel) components and simplify kernel code that
uses it.

This should also make it easier on userspace.
Signed-off-by: Sasha Levin <sashal@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Right now if SUBLEVEL becomes larger than 255 it will overflow into the
territory of PATCHLEVEL, causing havoc in userspace that tests for
specific kernel version.

While userspace code tests for MAJOR and PATCHLEVEL, it doesn't test
SUBLEVEL at any point as ABI changes don't happen in the context of
stable tree.

Thus, to avoid overflows, simply clamp SUBLEVEL to it's maximum value in
the context of LINUX_VERSION_CODE. This does not affect "make
kernelversion" and such.
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

DWARF v5 is the latest standard of the DWARF debug info format. GCC 11
will change the implicit default DWARF version, if left unspecified, to
DWARF v5.

Allow users of Clang and older versions of GCC that have not changed the
implicit default DWARF version to DWARF v5 to opt in. This can help
testing consumers of DWARF debug info in preparation of v5 becoming more
widespread, as well as result in significant binary size savings of the
pre-stripped vmlinux image.

DWARF5 wins significantly in terms of size when mixed with compression
(CONFIG_DEBUG_INFO_COMPRESSED).

363M    vmlinux.clang12.dwarf5.compressed
434M    vmlinux.clang12.dwarf4.compressed
439M    vmlinux.clang12.dwarf2.compressed
457M    vmlinux.clang12.dwarf5
536M    vmlinux.clang12.dwarf4
548M    vmlinux.clang12.dwarf2

515M    vmlinux.gcc10.2.dwarf5.compressed
599M    vmlinux.gcc10.2.dwarf4.compressed
624M    vmlinux.gcc10.2.dwarf2.compressed
630M    vmlinux.gcc10.2.dwarf5
765M    vmlinux.gcc10.2.dwarf4
809M    vmlinux.gcc10.2.dwarf2

Though the quality of debug info is harder to quantify; size is not a
proxy for quality.

Jakub notes:
  One thing is GCC DWARF-5 support, that is whether the compiler will
  support -gdwarf-5 flag, and that support should be there from GCC 7
  onwards.

  All [GCC] 5.1 - 6.x did was start accepting -gdwarf-5 as experimental
  option that enabled some small DWARF subset (initially only a few
  DW_LANG_* codes newly added to DWARF5 drafts).  Only GCC 7 (released
  after DWARF 5 has been finalized) started emitting DWARF5 section
  headers and got most of the DWARF5 changes in...

  Another separate thing is whether the assembler does support
  the -gdwarf-5 option (i.e. if you can compile assembler files
  with -Wa,-gdwarf-5) ... That option is about whether the assembler
  will emit DWARF5 or DWARF2 .debug_line.  It is fine to compile C sources
  with -gdwarf-5 and use DWARF2 .debug_line for assembler files if as
  doesn't support it.

Version check GCC so that we don't need to worry about the difference in
command line args between GNU readelf and llvm-readelf/llvm-dwarfdump to
validate the DWARF Version in the assembler feature detection script.

Most issues with clang produced assembler were fixed in binutils 2.35.1,
but 2.35.2 fixed issues related to requiring the flag -Wa,-gdwarf-5
explicitly. The added shell script test checks for the latter, and is
only required when using clang without its integrated assembler, though
we use for clang regardless as we do not yet have a way to query the
assembler from Kconfig.

Disabled for now if CONFIG_DEBUG_INFO_BTF is set; pahole doesn't yet
recognize the new additions to the DWARF debug info.

This only modifies the DWARF version emitted by the compiler, not the
assembler.

The DWARF version of a binary can be validated with:
$ llvm-dwarfdump <object file> | head -n 4 | grep version
or
$ readelf --debug-dump=info <object file> 2>/dev/null | grep Version

Parts of the tree don't reuse DEBUG_CFLAGS as they should; such cleanup
is left as a follow up.

Link: http://www.dwarfstd.org/doc/DWARF5.pdf
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1922707Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Suggested-by: Arvind Sankar <nivedita@alum.mit.edu>
Suggested-by: Caroline Tice <cmtice@google.com>
Suggested-by: Fangrui Song <maskray@google.com>
Suggested-by: Jakub Jelinek <jakub@redhat.com>
Suggested-by: Masahiro Yamada <masahiroy@kernel.org>
Suggested-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM/Clang v12.0.0-rc1 x86-64
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Adds a default CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT which allows
the implicit default version of DWARF emitted by the toolchain to
progress over time.

Modifies CONFIG_DEBUG_INFO_DWARF4 to be a member of a choice, making it
mutually exclusive with CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT. Users
may want to select this if they are using a newer toolchain, but have
consumers of the DWARF debug info that aren't yet ready for newer DWARF
versions' debug info.

Does so in a way that's forward compatible with existing
configs, and makes adding future versions more straightforward. This
patch does not change the current behavior or selection of DWARF
version for users upgrading to kernels with this patch.

GCC since ~4.8 has defaulted to DWARF v4 implicitly, and GCC 11 has
bumped this to v5.

Remove the Kconfig help text  about DWARF v4 being larger.  It's
empirically false for the latest toolchains for x86_64 defconfig, has no
point of reference (I suspect it was DWARF v2 but that's stil
empirically false), and debug info size is not a qualatative measure.
Suggested-by: Arvind Sankar <nivedita@alum.mit.edu>
Suggested-by: Fangrui Song <maskray@google.com>
Suggested-by: Jakub Jelinek <jakub@redhat.com>
Suggested-by: Mark Wielaard <mark@klomp.org>
Suggested-by: Masahiro Yamada <masahiroy@kernel.org>
Suggested-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

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: Chris Murphy <lists@colorremedies.com>
Suggested-by: Fangrui Song <maskray@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Mark Wielaard <mark@klomp.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Reduce repeated logic around expanding composite objects.
Signed-off-by: Elliot Berman <eberman@codeaurora.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

As commit d0e628cd ("kbuild: doc: clarify the difference between
extra-y and always-y") explained, extra-y should be used for listing
the prerequisites of vmlinux.

These targets are not related to vmlinux. always-y is a better fix.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Rob Herring <robh@kernel.org>

Revert commit 223c24a7 ("kbuild: Automatically remove stale
<linux/version.h> file").

It was more than 6 years ago. I do not expect anybody to start
git-bisect for such a big window.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

EXPORT_SYMBOL is unrelated to makefiles. No need to mention it.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

This switch statement does not list out all the cases. Since the
'default' covers all the rest, the 'DOTS' case is unneeded.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

No one sets lexstate to ST_TABLE_*. It is is very old code, and I do
not know what was the plan at that time. Let's remove the dead code.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

This is only used in yylex() in lex.l
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Paul Gortmaker reported a regression in the GCC version check. [1]
If you use GCC 4.8, the build breaks before showing the error message
"error Sorry, your version of GCC is too old - please use 4.9 or newer."

I do not want to apply his fix-up since it implies we would not be able
to remove any cc-option test. Anyway, I admit checking the GCC version
in <linux/compiler-gcc.h> is too late.

Almost at the same time, Linus also suggested to move the compiler
version error to Kconfig time. [2]

I unified the two similar scripts, gcc-version.sh and clang-version.sh
into cc-version.sh. The old scripts invoked the compiler multiple times
(3 times for gcc-version.sh, 4 times for clang-version.sh). I refactored
the code so the new one invokes the compiler just once, and also tried
my best to use shell-builtin commands where possible.

The new script runs faster.

  $ time ./scripts/clang-version.sh clang
  120000

  real    0m0.029s
  user    0m0.012s
  sys     0m0.021s

  $ time ./scripts/cc-version.sh clang
  Clang 120000

  real    0m0.009s
  user    0m0.006s
  sys     0m0.004s

cc-version.sh also shows an error message if the compiler is too old:

  $ make defconfig CC=clang-9
  *** Default configuration is based on 'x86_64_defconfig'
  ***
  *** Compiler is too old.
  ***   Your Clang version:    9.0.1
  ***   Minimum Clang version: 10.0.1
  ***
  scripts/Kconfig.include:46: Sorry, this compiler is not supported.
  make[1]: *** [scripts/kconfig/Makefile:81: defconfig] Error 1
  make: *** [Makefile:602: defconfig] Error 2

The new script takes care of ICC because we have <linux/compiler-intel.h>
although I am not sure if building the kernel with ICC is well-supported.

[1]: https://lore.kernel.org/r/20210110190807.134996-1-paul.gortmaker@windriver.com
[2]: https://lore.kernel.org/r/CAHk-=wh-+TMHPTFo1qs-MYyK7tZh-OQovA=pP3=e06aCVp6_kA@mail.gmail.com

Fixes: 87de84c9 ("kbuild: remove cc-option test of -Werror=date-time")
Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Tested-by: Miguel Ojeda <ojeda@kernel.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Commit ccbef167 ("Kbuild, lto: add ld-version and ld-ifversion
macros") introduced scripts/ld-version.sh for GCC LTO.

At that time, this script handled 5 version fields because GCC LTO
needed the downstream binutils. (https://lkml.org/lkml/2014/4/8/272)

The code snippet from the submitted patch was as follows:

    # We need HJ Lu's Linux binutils because mainline binutils does not
    # support mixing assembler and LTO code in the same ld -r object.
    # XXX check if the gcc plugin ld is the expected one too
    # XXX some Fedora binutils should also support it. How to check for that?
    ifeq ($(call ld-ifversion,-ge,22710001,y),y)
        ...

However, GCC LTO was not merged into the mainline after all.
(https://lkml.org/lkml/2014/4/8/272)

So, the 4th and 5th fields were never used, and finally removed by
commit 0d61ed17 ("ld-version: Drop the 4th and 5th version
components").

Since then, the last 4-digits returned by this script is always zeros.

Remove the meaningless last 4-digits. This makes the version format
consistent with GCC_VERSION, CLANG_VERSION, LLD_VERSION.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

The -gdwarf-4 flag is supported by GCC 4.5+, and also by Clang.

You can see it at https://godbolt.org/z/6ed1oW

  For gcc 4.5.3 pane,    line 37:    .value 0x4
  For clang 10.0.1 pane, line 117:   .short 4

Given Documentation/process/changes.rst stating GCC 4.9 is the minimal
version, this cc-option is unneeded.

Note
----

CONFIG_DEBUG_INFO_DWARF4 controls the DWARF version only for C files.

As you can see in the top Makefile, -gdwarf-4 is only passed to CFLAGS.

  ifdef CONFIG_DEBUG_INFO_DWARF4
  DEBUG_CFLAGS    += -gdwarf-4
  endif

This flag is used when compiling *.c files.

On the other hand, the assembler is always given -gdwarf-2.

  KBUILD_AFLAGS   += -Wa,-gdwarf-2

Hence, the debug info that comes from *.S files is always DWARF v2.
This is simply because GAS supported only -gdwarf-2 for a long time.

Recently, GAS gained the support for --gdwarf-[345] options. [1]
And, also we have Clang integrated assembler. So, the debug info
for *.S files might be improved in the future.

In my understanding, the current code is intentional, not a bug.

[1] https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=31bf18645d98b4d3d7357353be840e320649a67dSigned-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>

By default, xz without parameters uses a dictionary size of 8 MB.
However, most modules are much smaller than that.
The xz manpage states that 'increasing dictionary size usually improves
compression ratio, but a dictionary bigger than the uncompressed file
is waste of memory'.
Use a dictionary size of 2 MB for module compression, resulting in
slightly higher compression speed while still maintaining a good
compression ratio.
Signed-off-by: Tor Vic <torvic9@mailbox.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Randy reports the following warning when building ARCH=ia64 with
CONFIG_IA64_PALINFO=m:

../scripts/Makefile.build:68: 'arch/ia64/kernel/palinfo.ko' will not be built even though obj-m is specified.
../scripts/Makefile.build:69: You cannot use subdir-y/m to visit a module Makefile. Use obj-y/m instead.

This message is actually false-positive, and you can get palinfo.ko
correctly built. It is emitted in the archprepare stage, where Kbuild
descends into arch/ia64/kernel to generate include/generated/nr-irqs.h
instead of any kind of kernel objects.

arch/ia64/kernel/nr-irqs.c was introduced by commit 213060a4
("[IA64] pvops: paravirtualize NR_IRQS") to pre-calculate:

   NR_IRQS = max(IA64_NATIVE_NR_IRQS, XEN_NR_IRQS, FOO_NR_IRQS...)

Since commit d52eefb4 ("ia64/xen: Remove Xen support for ia64"), this
union contains just one field, making NR_IRQS and IA64_NATIVE_NR_IRQS
always match.

So, the following hard-coding now works:

  #define NR_IRQS                IA64_NATIVE_NR_IRQS

If you need to re-introduce NR_IRQS = max(...) gimmick in the future,
please try to implement it in asm-offsets.c instead of a separate file.
It will be possible because the header inclusion has been consolidated
to make asm-offsets.c independent of <asm/irqs.h>.
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>

<asm/mca.h> includes too many unneeded headers.

This commit cuts off a lot of header includes.

What we need to include are:

 - <linux/percpu.h> for DECLARE_PER_CPU(u64, ia64_mca_pal_base)
 - <linux/threads.h> for NR_CPUS
 - <linux/types.h> for u8, u64, size_t, etc.
 - <asm/ptrace.h> for KERNEL_STACK_SIZE

The other header includes are actually unneeded.

<asm/mca.h> previously included 436 headers, and now it includes
only 138. I confirmed <asm/mca.h> is still self-contained.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>

Documentation/process/coding-style.rst says:

  Please don't use things like ``vps_t``.
  It's a **mistake** to use typedef for structures and pointers.

This commit converts as follows:

  struct pal_min_state_area_s  ->  struct pal_min_state_area
         pal_min_state_area_t  ->  struct pal_min_state_area

My main motivation for this is to slim down the include directives
of <asm/mca.h> in the next commit.

Currently, <asm/mca.h> is required to include <asm/pal.h> directly
or indirectly due to (pal_min_state_area_t *). Otherwise, it would
have no idea what pal_min_state_area_t is.

Replacing it with (struct pal_min_state_area *) will relax the header
dependency since it is enough to tell it is a pointer to a structure,
and to resolve the size of struct pal_min_state_area. It will make
<asm/mca.h> independent of <asm/pal.h>.

<asm/pal.h> typedef's a lot of structures, but it is trivial to
convert the others in the same way.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>

Pull libnvdimm fixes from Dan Williams:
 "A fix for a crash scenario that has been present since the initial
  merge, a minor regression in sysfs attribute visibility, and a fix for
  some flexible array warnings.

  The bulk of this pull is an update to the libnvdimm unit test
  infrastructure to test non-ACPI platforms. Given there is zero
  regression risk for test updates, and the tests enable validation of
  bits headed towards the next merge window, I saw no reason to hold the
  new tests back. Santosh originally submitted this before the v5.11
  window opened.

  Summary:

   - Fix a crash when sysfs accesses race 'dimm' driver probe/remove.

   - Fix a regression in 'resource' attribute visibility necessary for
     mapping badblocks and other physical address interrogations.

   - Fix some flexible array warnings

   - Expand the unit test infrastructure for non-ACPI platforms"

* tag 'libnvdimm-fixes-5.11-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  libnvdimm/dimm: Avoid race between probe and available_slots_show()
  ndtest: Add papr health related flags
  ndtest: Add nvdimm control functions
  ndtest: Add regions and mappings to the test buses
  ndtest: Add dimm attributes
  ndtest: Add dimms to the two buses
  ndtest: Add compatability string to treat it as PAPR family
  testing/nvdimm: Add test module for non-nfit platforms
  libnvdimm/namespace: Fix visibility of namespace resource attribute
  libnvdimm/pmem: Remove unused header
  ACPI: NFIT: Fix flexible_array.cocci warnings

Pull dma-mapping fix from Christoph Hellwig:
 "Fix a 32 vs 64-bit padding issue in the new benchmark code (Barry
  Song)"

* tag 'dma-mapping-5.11-2' of git://git.infradead.org/users/hch/dma-mapping:
  dma-mapping: benchmark: use u8 for reserved field in uAPI structure

Pull irq fixes from Borislav Petkov:

 - Prevent device managed IRQ allocation helpers from returning IRQ 0

 - A fix for MSI activation of PCI endpoints with multiple MSIs

* tag 'irq_urgent_for_v5.11_rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq: Prevent [devm_]irq_alloc_desc from returning irq 0
  genirq/msi: Activate Multi-MSI early when MSI_FLAG_ACTIVATE_EARLY is set

Pull syscall entry fixes from Borislav Petkov:

 - For syscall user dispatch, separate prctl operation from syscall
   redirection range specification before the API has been made official
   in 5.11.

 - Ensure tasks using the generic syscall code do trap after returning
   from a syscall when single-stepping is requested.

* tag 'core_urgent_for_v5.11_rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  entry: Use different define for selector variable in SUD
  entry: Ensure trap after single-step on system call return

Pull scheduler fix from Borislav Petkov:
 "Revert an attempt to not spread IRQ threads on isolated CPUs which has
  a bunch of problems"

* tag 'sched_urgent_for_v5.11_rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Revert "lib: Restrict cpumask_local_spread to houskeeping CPUs"

Pull timer fixes from Borislav Petkov:
 "Two more timers-related fixes for v5.11:

   - Use a freezable workqueue for RTC sync because the sync can happen
     at any time and trigger suspend assertion checks in the i2c
     subsystem.

   - Correct a previous RTC validation change to check only bit 6 in
     register D because some Intel machines use bits 0-5"

* tag 'timers_urgent_for_v5.11_rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  ntp: Use freezable workqueue for RTC synchronization
  rtc: mc146818: Dont test for bit 0-5 in Register D

Pull x86 fixes from Borislav Petkov:
 "I hope this is the last batch of x86/urgent updates for this round:

   - Remove superfluous EFI PGD range checks which lead to those
     assertions failing with certain kernel configs and LLVM.

   - Disable setting breakpoints on facilities involved in #DB exception
     handling to avoid infinite loops.

   - Add extra serialization to non-serializing MSRs (IA32_TSC_DEADLINE
     and x2 APIC MSRs) to adhere to SDM's recommendation and avoid any
     theoretical issues.

   - Re-add the EPB MSR reading on turbostat so that it works on older
     kernels which don't have the corresponding EPB sysfs file.

   - Add Alder Lake to the list of CPUs which support split lock.

   - Fix %dr6 register handling in order to be able to set watchpoints
     with gdb again.

   - Disable CET instrumentation in the kernel so that gcc doesn't add
     ENDBR64 to kernel code and thus confuse tracing"

* tag 'x86_urgent_for_v5.11_rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/efi: Remove EFI PGD build time checks
  x86/debug: Prevent data breakpoints on cpu_dr7
  x86/debug: Prevent data breakpoints on __per_cpu_offset
  x86/apic: Add extra serialization for non-serializing MSRs
  tools/power/turbostat: Fallback to an MSR read for EPB
  x86/split_lock: Enable the split lock feature on another Alder Lake CPU
  x86/debug: Fix DR6 handling
  x86/build: Disable CET instrumentation in the kernel

Merge tag 'kbuild-fixes-v5.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

 - Use the 'python3' command to invoke python scripts because some
   distributions do not provide the 'python' command any more.

 - Clean-up and update documents

 - Use pkg-config to search libcrypto

 - Fix duplicated debug flags

 - Ignore some more stubs in scripts/kallsyms.c

* tag 'kbuild-fixes-v5.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kallsyms: fix nonconverging kallsyms table with lld
  kbuild: fix duplicated flags in DEBUG_CFLAGS
  scripts/clang-tools: switch explicitly to Python 3
  kbuild: remove PYTHON variable
  Documentation/llvm: Add a section about supported architectures
  Revert "checkpatch: add check for keyword 'boolean' in Kconfig definitions"
  scripts: use pkg-config to locate libcrypto
  kconfig: mconf: fix HOSTCC call
  doc: gcc-plugins: update gcc-plugins.rst
  kbuild: simplify GCC_PLUGINS enablement in dummy-tools/gcc
  Documentation/Kbuild: Remove references to gcc-plugin.sh
  scripts: switch explicitly to Python 3

Pull cifs fixes from Steve French:
 "Three small smb3 fixes for stable"

* tag '5.11-rc6-smb3' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: report error instead of invalid when revalidating a dentry fails
  smb3: fix crediting for compounding when only one request in flight
  smb3: Fix out-of-bounds bug in SMB2_negotiate()

Pull RISC-V fixes from Palmer Dabbelt:
 "A handful of fixes for this week:

   - A fix to avoid evalating the VA twice in virt_addr_valid, which
     fixes some WARNs under DEBUG_VIRTUAL.

   - Two fixes related to STRICT_KERNEL_RWX: one that fixes some
     permissions when strict is disabled, and one to fix some alignment
     issues when strict is enabled.

   - A fix to disallow the selection of MAXPHYSMEM_2GB on RV32, which
     isn't valid any more but may still show up in some oldconfigs.

  We still have the HiFive Unleashed ethernet phy reset regression, so
  there will likely be something coming next week"

* tag 'riscv-for-linus-5.11-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  RISC-V: Define MAXPHYSMEM_1GB only for RV32
  riscv: Align on L1_CACHE_BYTES when STRICT_KERNEL_RWX
  RISC-V: Fix .init section permission update
  riscv: virt_addr_valid must check the address belongs to linear mapping

Pull powerpc fixes from Michael Ellerman:

 - A fix for a change we made to __kernel_sigtramp_rt64() which confused
   glibc's backtrace logic, and also changed the semantics of that
   symbol, which was arguably an ABI break.

 - A fix for a stack overwrite in our VSX instruction emulation.

 - A couple of fixes for the Makefile logic in the new C VDSO.

Thanks to Masahiro Yamada, Naveen N.  Rao, Raoni Fassina Firmino, and
Ravi Bangoria.

* tag 'powerpc-5.11-7' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/64/signal: Fix regression in __kernel_sigtramp_rt64() semantics
  powerpc/vdso64: remove meaningless vgettimeofday.o build rule
  powerpc/vdso: fix unnecessary rebuilds of vgettimeofday.o
  powerpc/sstep: Fix array out of bound warning

Pull ARM fixes from Russell King:

 - Fix latent bug with DC21285 (Footbridge PCI bridge) configuration
   accessors that affects GCC >= 4.9.2

 - Fix misplaced tegra_uart_config in decompressor

 - Ensure signal page contents are initialised

 - Fix kexec oops

* tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm:
  ARM: kexec: fix oops after TLB are invalidated
  ARM: ensure the signal page contains defined contents
  ARM: 9043/1: tegra: Fix misplaced tegra_uart_config in decompressor
  ARM: footbridge: fix dc21285 PCI configuration accessors

Pull USB fixes from Greg KH:
 "Here are some small, last-minute, USB driver fixes for 5.11-rc7

  They all resolve issues reported, or are a few new device ids for some
  drivers. They include:

   - new device ids for some usb-serial drivers

   - xhci fixes for a variety of reported problems

   - dwc3 driver bugfixes

   - dwc2 driver bugfixes

   - usblp driver bugfix

   - thunderbolt bugfix

   - few other tiny fixes

  All have been in linux-next with no reported issues"

* tag 'usb-5.11-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usb: dwc2: Fix endpoint direction check in ep_from_windex
  usb: dwc3: fix clock issue during resume in OTG mode
  xhci: fix bounce buffer usage for non-sg list case
  usb: host: xhci: mvebu: make USB 3.0 PHY optional for Armada 3720
  usb: xhci-mtk: break loop when find the endpoint to drop
  usb: xhci-mtk: skip dropping bandwidth of unchecked endpoints
  usb: renesas_usbhs: Clear pipe running flag in usbhs_pkt_pop()
  USB: gadget: legacy: fix an error code in eth_bind()
  thunderbolt: Fix possible NULL pointer dereference in tb_acpi_add_link()
  USB: serial: option: Adding support for Cinterion MV31
  usb: xhci-mtk: fix unreleased bandwidth data
  usb: gadget: aspeed: add missing of_node_put
  USB: usblp: don't call usb_set_interface if there's a single alt
  USB: serial: cp210x: add pid/vid for WSDA-200-USB
  USB: serial: cp210x: add new VID/PID for supporting Teraoka AD2000

Pull input fixes from Dmitry Torokhov:
 "Nothing terribly interesting, just a few fixups"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: xpad - sync supported devices with fork on GitHub
  Input: ariel-pwrbutton - remove unused variable ariel_pwrbutton_id_table
  Input: goodix - add support for Goodix GT9286 chip
  dt-bindings: input: touchscreen: goodix: Add binding for GT9286 IC
  dt-bindings: input: adc-keys: clarify description
  Input: ili210x - implement pressure reporting for ILI251x
  Input: i8042 - unbreak Pegatron C15B
  Input: st1232 - wait until device is ready before reading resolution
  Input: st1232 - do not read more bytes than needed
  Input: st1232 - fix off-by-one error in resolution handling

Pull SCSI fix from James Bottomley:
 "One fix in drivers (lpfc) that stops an oops on resource exhaustion"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: lpfc: Fix EEH encountering oops with NVMe traffic

Pull block fixes from Jens Axboe:
 "A few small regression fixes:

   - NVMe pull request from Christoph:
       - more quirks for buggy devices (Thorsten Leemhuis, Claus Stovgaard)
       - update the email address for Keith (Keith Busch)
       - fix an out of bounds access in nvmet-tcp (Sagi Grimberg)

   - Regression fix for BFQ shallow depth calculations introduced in
     this merge window (Lin)"

* tag 'block-5.11-2021-02-05' of git://git.kernel.dk/linux-block:
  nvmet-tcp: fix out-of-bounds access when receiving multiple h2cdata PDUs
  bfq-iosched: Revert "bfq: Fix computation of shallow depth"
  update the email address for Keith Bush
  nvme-pci: ignore the subsysem NQN on Phison E16
  nvme-pci: avoid the deepest sleep state on Kingston A2000 SSDs

Pull io_uring fixes from Jens Axboe:
 "Two small fixes that should go into 5.11:

   - task_work resource drop fix (Pavel)

   - identity COW fix (Xiaoguang)"

* tag 'io_uring-5.11-2021-02-05' of git://git.kernel.dk/linux-block:
  io_uring: drop mm/files between task_work_submit
  io_uring: don't modify identity's files uncess identity is cowed

With CONFIG_X86_5LEVEL, CONFIG_UBSAN and CONFIG_UBSAN_UNSIGNED_OVERFLOW
enabled, clang fails the build with

  x86_64-linux-ld: arch/x86/platform/efi/efi_64.o: in function `efi_sync_low_kernel_mappings':
  efi_64.c:(.text+0x22c): undefined reference to `__compiletime_assert_354'

which happens due to -fsanitize=unsigned-integer-overflow being enabled:

  -fsanitize=unsigned-integer-overflow: Unsigned integer overflow, where
  the result of an unsigned integer computation cannot be represented
  in its type. Unlike signed integer overflow, this is not undefined
  behavior, but it is often unintentional. This sanitizer does not check
  for lossy implicit conversions performed before such a computation
  (see -fsanitize=implicit-conversion).

and that fires when the (intentional) EFI_VA_START/END defines overflow
an unsigned long, leading to the assertion expressions not getting
optimized away (on GCC they do)...

However, those checks are superfluous: the runtime services mapping
code already makes sure the ranges don't overshoot EFI_VA_END as the
EFI mapping range is hardcoded. On each runtime services call, it is
switched to the EFI-specific PGD and even if mappings manage to escape
that last PGD, this won't remain unnoticed for long.

So rip them out.

See https://github.com/ClangBuiltLinux/linux/issues/256 for more info.
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Link: http://lkml.kernel.org/r/20210107223424.4135538-1-arnd@kernel.org

Michael Kerrisk suggested that, from an API perspective, it is a bad
idea to share the PR_SYS_DISPATCH_ defines between the prctl operation
and the selector variable.

Therefore, define two new constants to be used by SUD's selector variable
and update the corresponding documentation and test cases.

While this changes the API syscall user dispatch has never been part of a
Linux release, it will show up for the first time in 5.11.
Suggested-by: Michael Kerrisk (man-pages) <mtk.manpages@gmail.com>
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210205184321.2062251-1-krisman@collabora.com