Currently we allocate the exception vector on systems which use a
vectored interrupt mode, but otherwise attempt to reuse whatever
exception vector the bootloader uses.

This can be problematic for a number of reasons:

  1) The memory isn't properly marked reserved in the memblock
     allocator. We've relied on the fact that EBase is generally in the
     memory below the kernel image which we don't free, but this is
     about to change.

  2) Recent versions of U-Boot place their exception vector high in
     kseg0, in memory which isn't protected by being lower than the
     kernel anyway & can end up being clobbered.

  3) We are unnecessarily reliant upon there being memory at the address
     EBase points to upon entry to the kernel. This is often the case,
     but if the bootloader doesn't configure EBase & leaves it with its
     default value then we rely upon there being memory at physical
     address 0 for no good reason.

Improve this situation by allocating the exception vector in all cases
when running on MIPSr2 or higher, and reserving the memory for MIPSr1 or
lower. This ensures we don't clobber the exception vector in any
configuration, and for MIPSr2 & higher removes the need for memory at
physical address 0.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Tested-by: Serge Semin <fancer.lancer@gmail.com>
Cc: linux-mips@vger.kernel.org

Allocate the exception vector using memblock_phys_alloc() which gives us
a physical address, rather than the previous convoluted setup which
obtained a virtual address using memblock_alloc(), converted it to a
physical address & then back to a virtual address.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Tested-by: Serge Semin <fancer.lancer@gmail.com>
Cc: linux-mips@vger.kernel.org

Before bootmem was completely removed from the kernel, the last loop
in the bootmem_init() had been used to reserve the correspondingly
marked regions, initialize sparsemem sections and to free the low memory
pages, which then would be used for early memory allocations. After the
bootmem removing patchset had been merged the loop was left to do the first
two things only. But it didn't do them quite well.

First of all it leaves the BOOT_MEM_INIT_RAM memory types unreserved,
which is definitely bug (although it isn't noticeable due to being used
by the kernel region only, which is fully marked as reserved). Secondly
the reservation is supposed to be done for any memory including the
high one. (I couldn't figure out why the highmem was ignored in the first
place, since platforms and dts' may declare any memory region for
reservation) Thirdly the reserved_end variable had been used here to not
accidentally free memory occupied by kernel. Since we already reserved the
corresponding region higher in this method there is no need in using the
variable here anymore. Fourthly the sparsemem should be aware of all the
memory types in the system including the ROM_DATA even if it is going to
be reserved for the whole system uptime. Finally after all these notes are
fixed the loop of memory reservation can be freely merged into the memory
installation loop as it's done in this patch.
Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Matt Redfearn <matt.redfearn@mips.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Thomas Bogendoerfer <tbogendoerfer@suse.de>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Stefan Agner <stefan@agner.ch>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

There is a pointless code left in the bootmem_init() method since
the bootmem allocator removal. First part resides the PFN ranges
calculation loop. The conditional expressions and continue operator
are useless there, since nothing is done after them. Second part is
in RAM ranges installation loop. We can simplify the conditions cascade
a bit without much of the logic redefinition, so to reduce the code
length. In particular the end boundary value can be verified after
the possible reduction to be below max_low_pfn.
Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Matt Redfearn <matt.redfearn@mips.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Thomas Bogendoerfer <tbogendoerfer@suse.de>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Stefan Agner <stefan@agner.ch>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

Current MIPS platform code makes sure the kernel text, data and init
sections are added to the boot memory map pool right after the
arch-specific memory setup method has been executed. But for some reason
the MIPS platform code skipped the kernel .bss section, which definitely
should be in the boot mem pool as well in any case. Lets fix this just be
adding the space between __bss_start and __bss_stop.
Reviewed-by: Matt Redfearn <matt.redfearn@mips.com>
Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Thomas Bogendoerfer <tbogendoerfer@suse.de>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Stefan Agner <stefan@agner.ch>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

Towards the goal of removing cc-ldoption, it seems that --hash-style=
was added to binutils 2.17.50.0.2 in 2006. The minimal required version
of binutils for the kernel according to
Documentation/process/changes.rst is 2.20.

--build-id was added in 2.18 according to binutils-gdb/ld/NEWS.

Link: https://gcc.gnu.org/ml/gcc/2007-01/msg01141.html
Cc: clang-built-linux@googlegroups.com
Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: ralf@linux-mips.org
Cc: jhogan@kernel.org
Cc: Matt Redfearn <matt.redfearn@mips.com>
Cc: Joel Stanley <joel@jms.id.au>
Cc: Hassan Naveed <hnaveed@wavecomp.com>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

Commit e6046b5e ("MIPS: ralink: fix cpu clock of mt7621 and add dt
clk devices") includes a file that doesn't exist, causing build
failures... Revert it.

References: https://lore.kernel.org/linux-mips/CAJsYDVJvviz8a2oVmb0XL3OB+=Eecu-3kC9T9vsmxpuC_BqDSA@mail.gmail.com/Signed-off-by: Paul Burton <paul.burton@mips.com>

Enable CONFIG_JUMP_LABEL for generic configs in order to better optimize
at runtime and get better test coverage for our jump label support.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org

MIPSr6 introduced compact branches which have no delay slots. Make use
of them for jump labels in order to avoid the need for a nop to fill the
branch or jump delay slot, saving 4 bytes of code for each static branch.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org

Both arch_static_branch() & arch_static_branch_jump() emit a control
transfer instruction (ie. branch or jump) without disabling assembler
re-ordering. As such the assembler will automatically fill their delay
slots.

Both functions follow their branch or jump with an explicit nop that at
first appears to be there to fill the delay slot, but given that the
assembler will do that the explicit nops serve no purpose & we end up
with our branch or jump followed by 2 nops. Remove the redundant nops.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org

A small batch of MIPS fixes for 5.1:

- An interrupt masking fix for Loongson-based Lemote 2F systems (fixing
  a regression from v3.19).

- A relocation fix for configurations in which the devicetree is stored
  in an ELF section (fixing a regression from v4.7).

- Fix jump labels for MIPSr6 kernels where they previously could
  inadvertently place a control transfer instruction in a forbidden slot
  & take unexpected exceptions (fixing MIPSr6 support added in v4.0).

- Extend an existing USB power workaround for the Netgear WNDR3400 to v2
  boards in addition to the v3 ones that already used it.

- Remove the custom MIPS32 definition of __kernel_fsid_t to make it
  consistent with MIPS64 & every other architecture, in particular
  resolving issues for code which tries to print the val field whose
  type previously differed (though had identical memory layout).

Merged into mips-next to gain the MIPSr6 jump label fix before enabling
jump labels by default for generic kernel builds.
Signed-off-by: Paul Burton <paul.burton@mips.com>

For a long time the mt7621 uses a fixed cpu clock which causes a problem
if the cpu frequency is not 880MHz.

This patch fixes the cpu clock calculation and adds the cpu/bus clkdev
which will be used in dts.

Ported from OpenWrt:
c7ca224299 ramips: fix cpu clock of mt7621 and add dt clk devices
Signed-off-by: Weijie Gao <hackpascal@gmail.com>
Signed-off-by: Chuanhong Guo <gch981213@gmail.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: John Crispin <john@phrozen.org>
Cc: linux-kernel@vger.kernel.org

Emulation of the tlbwr instruction, which writes a TLB entry to a random
index in the TLB, currently uses get_random_bytes() to generate a 4 byte
random number which we then mask to form the index. This is overkill in
a couple of ways:

  - We don't need 4 bytes here since we mask the value to form a 6 bit
    number anyway, so we waste /dev/random entropy generating 3 random
    bytes that are unused.

  - We don't need crypto-grade randomness here - the architecture spec
    allows implementations to use any algorithm & merely encourages that
    some pseudo-randomness be used rather than a simple counter. The
    fast prandom_u32() function fits that criteria well.

So rather than using get_random_bytes() & consuming /dev/random entropy,
switch to using the faster prandom_u32_max() which provides what we need
here whilst also performing the masking/modulo for us.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Reported-by: George Spelvin <lkml@sdf.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@vger.kernel.org

Formatting of Kconfig files doesn't look so pretty, so let the
Great White Handkerchief come around and clean it up.
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-kernel@vger.kernel.org
Cc: hauke@hauke-m.de
Cc: zajec5@gmail.com
Cc: f.fainelli@gmail.com
Cc: bcm-kernel-feedback-list@broadcom.com
Cc: linux-mips@vger.kernel.org

Currently MIPS32 supports a JIT for classic BPF only, not extended BPF.
This patch adds JIT support for extended BPF on MIPS32, so code is
actually JIT'ed instead of being only interpreted. Instructions with
64-bit operands are not supported at this point.
We can delete classic BPF because the kernel will translate classic BPF
programs into extended BPF and JIT them, eliminating the need for
classic BPF.
Signed-off-by: Hassan Naveed <hnaveed@wavecomp.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: kafai@fb.com
Cc: songliubraving@fb.com
Cc: yhs@fb.com
Cc: netdev@vger.kernel.org
Cc: bpf@vger.kernel.org
Cc: linux-mips@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: open list:MIPS <linux-mips@linux-mips.org>
Cc: open list <linux-kernel@vger.kernel.org>

Currently eBPF support is available on MIPS64R2 only. Use MIPS64R6
variants of instructions like multiply, divide, movn, movz so eBPF
can run on the newer ISA. Also, we only need to check ISA revision
before JIT'ing code, because we know the CPU is running a 64-bit
kernel because eBPF JIT is only included in kernels with CONFIG_64BIT=y
due to Kconfig dependencies.
Signed-off-by: Hassan Naveed <hnaveed@wavecomp.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: kafai@fb.com
Cc: songliubraving@fb.com
Cc: yhs@fb.com
Cc: netdev@vger.kernel.org
Cc: bpf@vger.kernel.org
Cc: linux-mips@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: open list:MIPS <linux-mips@linux-mips.org>
Cc: open list <linux-kernel@vger.kernel.org>

Add the following instructions for use by eBPF on mipsr6:
insn_ddivu_r6, insn_divu_r6, insn_dmodu, insn_dmulu, insn_modu,
insn_mulu, insn_seleqz, insn_selnez
Signed-off-by: Hassan Naveed <hnaveed@wavecomp.com>
Reviewed-by: Paul Burton <paul.burton@mips.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: kafai@fb.com
Cc: songliubraving@fb.com
Cc: yhs@fb.com
Cc: netdev@vger.kernel.org
Cc: bpf@vger.kernel.org
Cc: linux-mips@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: open list:MIPS <linux-mips@linux-mips.org>
Cc: open list <linux-kernel@vger.kernel.org>

Since the enabling and disabling of IRQs within preempt_schedule_irq()
is contained in a need_resched() loop, we don't need the outer arch
code loop.

Note that commit a18815ab ("Use preempt_schedule_irq.") initially
removed the existing loop, but missed the final branch to restore_all.
Commit cdaed73a ("Fix preemption bug.") missed that and reintroduced
the loop.
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@vger.kernel.org
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-kernel@vger.kernel.org

Pull more Kbuild updates from Masahiro Yamada:

 - add more Build-Depends to Debian source package

 - prefix header search paths with $(srctree)/

 - make modpost show verbose section mismatch warnings

 - avoid hard-coded CROSS_COMPILE for h8300

 - fix regression for Debian make-kpkg command

 - add semantic patch to detect missing put_device()

 - fix some warnings of 'make deb-pkg'

 - optimize NOSTDINC_FLAGS evaluation

 - add warnings about redundant generic-y

 - clean up Makefiles and scripts

* tag 'kbuild-v5.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kconfig: remove stale lxdialog/.gitignore
  kbuild: force all architectures except um to include mandatory-y
  kbuild: warn redundant generic-y
  Revert "modsign: Abort modules_install when signing fails"
  kbuild: Make NOSTDINC_FLAGS a simply expanded variable
  kbuild: deb-pkg: avoid implicit effects
  coccinelle: semantic code search for missing put_device()
  kbuild: pkg: grep include/config/auto.conf instead of $KCONFIG_CONFIG
  kbuild: deb-pkg: introduce is_enabled and if_enabled_echo to builddeb
  kbuild: deb-pkg: add CONFIG_ prefix to kernel config options
  kbuild: add workaround for Debian make-kpkg
  kbuild: source include/config/auto.conf instead of ${KCONFIG_CONFIG}
  unicore32: simplify linker script generation for decompressor
  h8300: use cc-cross-prefix instead of hardcoding h8300-unknown-linux-
  kbuild: move archive command to scripts/Makefile.lib
  modpost: always show verbose warning for section mismatch
  ia64: prefix header search path with $(srctree)/
  libfdt: prefix header search paths with $(srctree)/
  deb-pkg: generate correct build dependencies

Pull x86 asm updates from Thomas Gleixner:
 "Two cleanup patches removing dead conditionals and unused code"

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/asm: Remove unused __constant_c_x_memset() macro and inlines
  x86/asm: Remove dead __GNUC__ conditionals

Pull perf fixes from Thomas Gleixner:
 "Three fixes for the fallout from the TSX errata workaround:

   - Prevent memory corruption caused by a unchecked out of bound array
     index.

   - Two trivial fixes to address compiler warnings"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel: Make dev_attr_allow_tsx_force_abort static
  perf/x86: Fixup typo in stub functions
  perf/x86/intel: Fix memory corruption

Pull xen fix from Juergen Gross:
 "A fix for a Xen bug introduced by David's series for excluding
  ballooned pages in vmcores"

* tag 'for-linus-5.1b-rc1b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/balloon: Fix mapping PG_offline pages to user space

Pull 9p updates from Dominique Martinet:
 "Here is a 9p update for 5.1; there honestly hasn't been much.

  Two fixes (leak on invalid mount argument and possible deadlock on
  i_size update on 32bit smp) and a fall-through warning cleanup"

* tag '9p-for-5.1' of git://github.com/martinetd/linux:
  9p/net: fix memory leak in p9_client_create
  9p: use inode->i_lock to protect i_size_write() under 32-bit
  9p: mark expected switch fall-through

Fixes: 400816f6 ("perf/x86/intel: Implement support for TSX Force Abort")
Signed-off-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: kbuild-all@01.org
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20190313184243.GA10820@lkp-sb-ep06

When this .gitignore was added, lxdialog was an independent hostprogs-y.

Now that all objects in lxdialog/ are directly linked to mconf, the
lxdialog is no longer generated.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

Currently, every arch/*/include/uapi/asm/Kbuild explicitly includes
the common Kbuild.asm file. Factor out the duplicated include directives
to scripts/Makefile.asm-generic so that no architecture would opt out
of the mandatory-y mechanism.

um is not forced to include mandatory-y since it is a very exceptional
case which does not support UAPI.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

The generic-y is redundant under the following condition:

 - arch has its own implementation

 - the same header is added to generated-y

 - the same header is added to mandatory-y

If a redundant generic-y is found, the warning like follows is displayed:

  scripts/Makefile.asm-generic:20: redundant generic-y found in arch/arm/include/asm/Kbuild: timex.h

I fixed up arch Kbuild files found by this.
Suggested-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

This reverts commit caf6fe91.

The commit was fine but is no longer needed as of commit 3a2429e1
("kbuild: change if_changed_rule for multi-line recipe").  Let's go
back to using ";" to be consistent.

For some discussion, see:

https://lkml.kernel.org/r/CAK7LNASde0Q9S5GKeQiWhArfER4S4wL1=R_FW8q0++_X3T5=hQ@mail.gmail.comSigned-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

During a simple no-op (nothing changed) build I saw 39 invocations of
the C compiler with the argument "-print-file-name=include".  We don't
need to call the C compiler 39 times for this--one time will suffice.

Let's change NOSTDINC_FLAGS to a simply expanded variable to avoid
this since there doesn't appear to be any reason it should be
recursively expanded.

On my build this shaved ~400 ms off my "no-op" build.

Note that the recursive expansion seems to date back to the (really
old) commit e8f5bdb0 ("[PATCH] Makefile include path ordering").
It's a little unclear to me if the point of that patch was to switch
the variable to be recursively expanded (which it did) or to avoid
directly assigning to NOSTDINC_FLAGS (AKA to switch to +=) because
someone else (out of tree?) was setting it.  I presume later since if
the only goal was to switch to recursive expansion the patch would
have just removed the ":".
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

* The man page for dpkg-source(1) notes:

>      -b, --build directory [format-specific-parameters]
>             Build  a  source  package  (--build since dpkg 1.17.14).
>             <...>
>
>             dpkg-source will build the source package with the first
>             format found in this ordered list: the format  indicated
>             with  the  --format  command  line  option,  the  format
>             indicated in debian/source/format, “1.0”.  The  fallback
>             to “1.0” is deprecated and will be removed at some point
>             in the future, you should always  document  the  desired
>             source   format  in  debian/source/format.  See  section
>             SOURCE PACKAGE FORMATS for an extensive  description  of
>             the various source package formats.

  Thus it would be more foolproof to explicitly use 1.0 (as we always
  did) than to rely on dpkg-source's defaults.

* In a similar vein, debian/rules is not made executable by mkdebian,
  and dpkg-source warns about that but still silently fixes the file.
  Let's be explicit once again.
Signed-off-by: Arseny Maslennikov <ar@cs.msu.ru>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

The of_find_device_by_node() takes a reference to the underlying device
structure, we should release that reference.
The implementation of this semantic code search is:
In a function, for a local variable returned by calling
of_find_device_by_node(),
a, if it is released by a function such as
   put_device()/of_dev_put()/platform_device_put() after the last use,
   it is considered that there is no reference leak;
b, if it is passed back to the caller via
   dev_get_drvdata()/platform_get_drvdata()/get_device(), etc., the
   reference will be released in other functions, and the current function
   also considers that there is no reference leak;
c, for the rest of the situation, the current function should release the
   reference by calling put_device, this code search will report the
   corresponding error message.

By using this semantic code search, we have found some object reference leaks,
such as:
commit 11907e9d ("ASoC: fsl-asoc-card: fix object reference leaks in
fsl_asoc_card_probe")
commit a12085d1 ("mtd: rawnand: atmel: fix possible object reference leak")
commit 11493f26 ("mtd: rawnand: jz4780: fix possible object reference leak")

There are still dozens of reference leaks in the current kernel code.

Further, for the case of b, the object returned to other functions may also
have a reference leak, we will continue to develop other cocci scripts to
further check the reference leak.
Signed-off-by: Wen Yang <wen.yang99@zte.com.cn>
Reviewed-by: Julia Lawall <Julia.Lawall@lip6.fr>
Reviewed-by: Markus Elfring <Markus.Elfring@web.de>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

Pull pidfd system call from Christian Brauner:
 "This introduces the ability to use file descriptors from /proc/<pid>/
  as stable handles on struct pid. Even if a pid is recycled the handle
  will not change. For a start these fds can be used to send signals to
  the processes they refer to.

  With the ability to use /proc/<pid> fds as stable handles on struct
  pid we can fix a long-standing issue where after a process has exited
  its pid can be reused by another process. If a caller sends a signal
  to a reused pid it will end up signaling the wrong process.

  With this patchset we enable a variety of use cases. One obvious
  example is that we can now safely delegate an important part of
  process management - sending signals - to processes other than the
  parent of a given process by sending file descriptors around via scm
  rights and not fearing that the given process will have been recycled
  in the meantime. It also allows for easy testing whether a given
  process is still alive or not by sending signal 0 to a pidfd which is
  quite handy.

  There has been some interest in this feature e.g. from systems
  management (systemd, glibc) and container managers. I have requested
  and gotten comments from glibc to make sure that this syscall is
  suitable for their needs as well. In the future I expect it to take on
  most other pid-based signal syscalls. But such features are left for
  the future once they are needed.

  This has been sitting in linux-next for quite a while and has not
  caused any issues. It comes with selftests which verify basic
  functionality and also test that a recycled pid cannot be signaled via
  a pidfd.

  Jon has written about a prior version of this patchset. It should
  cover the basic functionality since not a lot has changed since then:

      https://lwn.net/Articles/773459/

  The commit message for the syscall itself is extensively documenting
  the syscall, including it's functionality and extensibility"

* tag 'pidfd-v5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
  selftests: add tests for pidfd_send_signal()
  signal: add pidfd_send_signal() syscall

Pull device-dax updates from Dan Williams:
 "New device-dax infrastructure to allow persistent memory and other
  "reserved" / performance differentiated memories, to be assigned to
  the core-mm as "System RAM".

  Some users want to use persistent memory as additional volatile
  memory. They are willing to cope with potential performance
  differences, for example between DRAM and 3D Xpoint, and want to use
  typical Linux memory management apis rather than a userspace memory
  allocator layered over an mmap() of a dax file. The administration
  model is to decide how much Persistent Memory (pmem) to use as System
  RAM, create a device-dax-mode namespace of that size, and then assign
  it to the core-mm. The rationale for device-dax is that it is a
  generic memory-mapping driver that can be layered over any "special
  purpose" memory, not just pmem. On subsequent boots udev rules can be
  used to restore the memory assignment.

  One implication of using pmem as RAM is that mlock() no longer keeps
  data off persistent media. For this reason it is recommended to enable
  NVDIMM Security (previously merged for 5.0) to encrypt pmem contents
  at rest. We considered making this recommendation an actively enforced
  requirement, but in the end decided to leave it as a distribution /
  administrator policy to allow for emulation and test environments that
  lack security capable NVDIMMs.

  Summary:

   - Replace the /sys/class/dax device model with /sys/bus/dax, and
     include a compat driver so distributions can opt-in to the new ABI.

   - Allow for an alternative driver for the device-dax address-range

   - Introduce the 'kmem' driver to hotplug / assign a device-dax
     address-range to the core-mm.

   - Arrange for the device-dax target-node to be onlined so that the
     newly added memory range can be uniquely referenced by numa apis"

NOTE! I'm not entirely happy with the whole "PMEM as RAM" model because
we currently have special - and very annoying rules in the kernel about
accessing PMEM only with the "MC safe" accessors, because machine checks
inside the regular repeat string copy functions can be fatal in some
(not described) circumstances.

And apparently the PMEM modules can cause that a lot more than regular
RAM.  The argument is that this happens because PMEM doesn't necessarily
get scrubbed at boot like RAM does, but that is planned to be added for
the user space tooling.

Quoting Dan from another email:
 "The exposure can be reduced in the volatile-RAM case by scanning for
  and clearing errors before it is onlined as RAM. The userspace tooling
  for that can be in place before v5.1-final. There's also runtime
  notifications of errors via acpi_nfit_uc_error_notify() from
  background scrubbers on the DIMM devices. With that mechanism the
  kernel could proactively clear newly discovered poison in the volatile
  case, but that would be additional development more suitable for v5.2.

  I understand the concern, and the need to highlight this issue by
  tapping the brakes on feature development, but I don't see PMEM as RAM
  making the situation worse when the exposure is also there via DAX in
  the PMEM case. Volatile-RAM is arguably a safer use case since it's
  possible to repair pages where the persistent case needs active
  application coordination"

* tag 'devdax-for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  device-dax: "Hotplug" persistent memory for use like normal RAM
  mm/resource: Let walk_system_ram_range() search child resources
  mm/memory-hotplug: Allow memory resources to be children
  mm/resource: Move HMM pr_debug() deeper into resource code
  mm/resource: Return real error codes from walk failures
  device-dax: Add a 'modalias' attribute to DAX 'bus' devices
  device-dax: Add a 'target_node' attribute
  device-dax: Auto-bind device after successful new_id
  acpi/nfit, device-dax: Identify differentiated memory with a unique numa-node
  device-dax: Add /sys/class/dax backwards compatibility
  device-dax: Add support for a dax override driver
  device-dax: Move resource pinning+mapping into the common driver
  device-dax: Introduce bus + driver model
  device-dax: Start defining a dax bus model
  device-dax: Remove multi-resource infrastructure
  device-dax: Kill dax_region base
  device-dax: Kill dax_region ida

Pull more SCSI updates from James Bottomley:
 "This is the final round of mostly small fixes and performance
  improvements to our initial submit.

  The main regression fix is the ia64 simscsi build failure which was
  missed in the serial number elimination conversion"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (24 commits)
  scsi: ia64: simscsi: use request tag instead of serial_number
  scsi: aacraid: Fix performance issue on logical drives
  scsi: lpfc: Fix error codes in lpfc_sli4_pci_mem_setup()
  scsi: libiscsi: Hold back_lock when calling iscsi_complete_task
  scsi: hisi_sas: Change SERDES_CFG init value to increase reliability of HiLink
  scsi: hisi_sas: Send HARD RESET to clear the previous affiliation of STP target port
  scsi: hisi_sas: Set PHY linkrate when disconnected
  scsi: hisi_sas: print PHY RX errors count for later revision of v3 hw
  scsi: hisi_sas: Fix a timeout race of driver internal and SMP IO
  scsi: hisi_sas: Change return variable type in phy_up_v3_hw()
  scsi: qla2xxx: check for kstrtol() failure
  scsi: lpfc: fix 32-bit format string warning
  scsi: lpfc: fix unused variable warning
  scsi: target: tcmu: Switch to bitmap_zalloc()
  scsi: libiscsi: fall back to sendmsg for slab pages
  scsi: qla2xxx: avoid printf format warning
  scsi: lpfc: resolve static checker warning in lpfc_sli4_hba_unset
  scsi: lpfc: Correct __lpfc_sli_issue_iocb_s4 lockdep check
  scsi: ufs: hisi: fix ufs_hba_variant_ops passing
  scsi: qla2xxx: Fix panic in qla_dfs_tgt_counters_show
  ...

Pull more block layer changes from Jens Axboe:
 "This is a collection of both stragglers, and fixes that came in after
  I finalized the initial pull. This contains:

   - An MD pull request from Song, with a few minor fixes

   - Set of NVMe patches via Christoph

   - Pull request from Konrad, with a few fixes for xen/blkback

   - pblk fix IO calculation fix (Javier)

   - Segment calculation fix for pass-through (Ming)

   - Fallthrough annotation for blkcg (Mathieu)"

* tag 'for-5.1/block-post-20190315' of git://git.kernel.dk/linux-block: (25 commits)
  blkcg: annotate implicit fall through
  nvme-tcp: support C2HData with SUCCESS flag
  nvmet: ignore EOPNOTSUPP for discard
  nvme: add proper write zeroes setup for the multipath device
  nvme: add proper discard setup for the multipath device
  nvme: remove nvme_ns_config_oncs
  nvme: disable Write Zeroes for qemu controllers
  nvmet-fc: bring Disconnect into compliance with FC-NVME spec
  nvmet-fc: fix issues with targetport assoc_list list walking
  nvme-fc: reject reconnect if io queue count is reduced to zero
  nvme-fc: fix numa_node when dev is null
  nvme-fc: use nr_phys_segments to determine existence of sgl
  nvme-loop: init nvmet_ctrl fatal_err_work when allocate
  nvme: update comment to make the code easier to read
  nvme: put ns_head ref if namespace fails allocation
  nvme-trace: fix cdw10 buffer overrun
  nvme: don't warn on block content change effects
  nvme: add get-feature to admin cmds tracer
  md: Fix failed allocation of md_register_thread
  It's wrong to add len to sector_nr in raid10 reshape twice
  ...

Pull NFS client bugfixes from Trond Myklebust:
 "Highlights include:

  Bugfixes:
   - Fix an Oops in SUNRPC back channel tracepoints
   - Fix a SUNRPC client regression when handling oversized replies
   - Fix the minimal size for SUNRPC reply buffer allocation
   - rpc_decode_header() must always return a non-zero value on error
   - Fix a typo in pnfs_update_layout()

  Cleanup:
   - Remove redundant check for the reply length in call_decode()"

* tag 'nfs-for-5.1-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  SUNRPC: Remove redundant check for the reply length in call_decode()
  SUNRPC: Handle the SYSTEM_ERR rpc error
  SUNRPC: rpc_decode_header() must always return a non-zero value on error
  SUNRPC: Use the ENOTCONN error on socket disconnect
  SUNRPC: Fix the minimal size for reply buffer allocation
  SUNRPC: Fix a client regression when handling oversized replies
  pNFS: Fix a typo in pnfs_update_layout
  fix null pointer deref in tracepoints in back channel

Pull powerpc fixes from Michael Ellerman:
 "One fix to prevent runtime allocation of 16GB pages when running in a
  VM (as opposed to bare metal), because it doesn't work.

  A small fix to our recently added KCOV support to exempt some more
  code from being instrumented.

  Plus a few minor build fixes, a small dead code removal and a
  defconfig update.

  Thanks to: Alexey Kardashevskiy, Aneesh Kumar K.V, Christophe Leroy,
  Jason Yan, Joel Stanley, Mahesh Salgaonkar, Mathieu Malaterre"

* tag 'powerpc-5.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/64s: Include <asm/nmi.h> header file to fix a warning
  powerpc/powernv: Fix compile without CONFIG_TRACEPOINTS
  powerpc/mm: Disable kcov for SLB routines
  powerpc: remove dead code in head_fsl_booke.S
  powerpc/configs: Sync skiroot defconfig
  powerpc/hugetlb: Don't do runtime allocation of 16G pages in LPAR configuration

Pull vfs mount infrastructure fix from Al Viro:
 "Fixup for sysfs braino.

  Capabilities checks for sysfs mount do include those on netns, but
  only if CONFIG_NET_NS is enabled. Sorry, should've caught that
  earlier..."

* 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fix sysfs_init_fs_context() in !CONFIG_NET_NS case

Permission checks on current's netns should be done only when
netns are enabled.
Reported-by: Dominik Brodowski <linux@dominikbrodowski.net>
Fixes: 23bf1b6bSigned-off-by: Al Viro <viro@zeniv.linux.org.uk>