linux-stable.git/arch/arc, branch v5.4.97

arch/arc: add copy_user_page() to to fix build error on ARC

2021-01-19T17:26:15+00:00

[ Upstream commit 8a48c0a3360bf2bf4f40c980d0ec216e770e58ee ]

fs/dax.c uses copy_user_page() but ARC does not provide that interface,
resulting in a build error.

Provide copy_user_page() in .

../fs/dax.c: In function 'copy_cow_page_dax':
../fs/dax.c:702:2: error: implicit declaration of function 'copy_user_page'; did you mean 'copy_to_user_page'? [-Werror=implicit-function-declaration]

Reported-by: kernel test robot 
Signed-off-by: Randy Dunlap 
Cc: Vineet Gupta 
Cc: linux-snps-arc@lists.infradead.org
Cc: Dan Williams 
#Acked-by: Vineet Gupta  # v1
Cc: Andrew Morton 
Cc: Matthew Wilcox 
Cc: Jan Kara 
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-nvdimm@lists.01.org
#Reviewed-by: Ira Weiny  # v2
Signed-off-by: Vineet Gupta 
Signed-off-by: Sasha Levin

ARC: build: move symlink creation to arch/arc/Makefile to avoid race

2021-01-19T17:26:14+00:00

[ Upstream commit c5e6ae563c802c4d828d42e134af64004db2e58c ]

If you run 'make uImage uImage.gz' with the parallel option, uImage.gz
will be created by two threads simultaneously.

This is because arch/arc/Makefile does not specify the dependency
between uImage and uImage.gz. Hence, GNU Make assumes they can be
built in parallel. One thread descends into arch/arc/boot/ to create
uImage, and another to create uImage.gz.

Please notice the same log is displayed twice in the following steps:

  $ export CROSS_COMPILE=
  $ make -s ARCH=arc defconfig
  $ make -j$(nproc) ARCH=arc uImage uImage.gz
  [ snip ]
    LD      vmlinux
    SORTTAB vmlinux
    SYSMAP  System.map
    OBJCOPY arch/arc/boot/vmlinux.bin
    OBJCOPY arch/arc/boot/vmlinux.bin
    GZIP    arch/arc/boot/vmlinux.bin.gz
    GZIP    arch/arc/boot/vmlinux.bin.gz
    UIMAGE  arch/arc/boot/uImage.gz
    UIMAGE  arch/arc/boot/uImage.gz
  Image Name:   Linux-5.10.0-rc4-00003-g62f23044
  Created:      Sun Nov 22 02:52:26 2020
  Image Type:   ARC Linux Kernel Image (gzip compressed)
  Data Size:    2109376 Bytes = 2059.94 KiB = 2.01 MiB
  Load Address: 80000000
  Entry Point:  80004000
    Image arch/arc/boot/uImage is ready
  Image Name:   Linux-5.10.0-rc4-00003-g62f23044
  Created:      Sun Nov 22 02:52:26 2020
  Image Type:   ARC Linux Kernel Image (gzip compressed)
  Data Size:    2815455 Bytes = 2749.47 KiB = 2.69 MiB
  Load Address: 80000000
  Entry Point:  80004000

This is a race between the two threads trying to write to the same file
arch/arc/boot/uImage.gz. This is a potential problem that can generate
a broken file.

I fixed a similar problem for ARM by commit 3939f3345050 ("ARM: 8418/1:
add boot image dependencies to not generate invalid images").

I highly recommend to avoid such build rules that cause a race condition.

Move the uImage rule to arch/arc/Makefile.

Another strangeness is that arch/arc/boot/Makefile compares the
timestamps between $(obj)/uImage and $(obj)/uImage.*:

  $(obj)/uImage: $(obj)/uImage.$(suffix-y)
          @ln -sf $(notdir $<) $@
          @echo '  Image $@ is ready'

This does not work as expected since $(obj)/uImage is a symlink.
The symlink should be created in a phony target rule.

I used $(kecho) instead of echo to suppress the message
'Image arch/arc/boot/uImage is ready' when the -s option is given.

Signed-off-by: Masahiro Yamada 
Signed-off-by: Vineet Gupta 
Signed-off-by: Sasha Levin

ARC: build: add boot_targets to PHONY

2021-01-19T17:26:14+00:00

[ Upstream commit 0cfccb3c04934cdef42ae26042139f16e805b5f7 ]

The top-level boot_targets (uImage and uImage.*) should be phony
targets. They just let Kbuild descend into arch/arc/boot/ and create
files there.

If a file exists in the top directory with the same name, the boot
image will not be created.

You can confirm it by the following steps:

  $ export CROSS_COMPILE=
  $ make -s ARCH=arc defconfig all   # vmlinux will be built
  $ touch uImage.gz
  $ make ARCH=arc uImage.gz
  CALL    scripts/atomic/check-atomics.sh
  CALL    scripts/checksyscalls.sh
  CHK     include/generated/compile.h
  # arch/arc/boot/uImage.gz is not created

Specify the targets as PHONY to fix this.

Signed-off-by: Masahiro Yamada 
Signed-off-by: Vineet Gupta 
Signed-off-by: Sasha Levin

ARC: build: add uImage.lzma to the top-level target

2021-01-19T17:26:14+00:00

[ Upstream commit f2712ec76a5433e5ec9def2bd52a95df1f96d050 ]

arch/arc/boot/Makefile supports uImage.lzma, but you cannot do
'make uImage.lzma' because the corresponding target is missing
in arch/arc/Makefile. Add it.

I also changed the assignment operator '+=' to ':=' since this is the
only place where we expect this variable to be set.

Signed-off-by: Masahiro Yamada 
Signed-off-by: Vineet Gupta 
Signed-off-by: Sasha Levin

ARC: build: remove non-existing bootpImage from KBUILD_IMAGE

2021-01-19T17:26:14+00:00

[ Upstream commit 9836720911cfec25d3fbdead1c438bf87e0f2841 ]

The deb-pkg builds for ARCH=arc fail.

  $ export CROSS_COMPILE=
  $ make -s ARCH=arc defconfig
  $ make ARCH=arc bindeb-pkg
  SORTTAB vmlinux
  SYSMAP  System.map
  MODPOST Module.symvers
  make KERNELRELEASE=5.10.0-rc4 ARCH=arc KBUILD_BUILD_VERSION=2 -f ./Makefile intdeb-pkg
  sh ./scripts/package/builddeb
  cp: cannot stat 'arch/arc/boot/bootpImage': No such file or directory
  make[4]: *** [scripts/Makefile.package:87: intdeb-pkg] Error 1
  make[3]: *** [Makefile:1527: intdeb-pkg] Error 2
  make[2]: *** [debian/rules:13: binary-arch] Error 2
  dpkg-buildpackage: error: debian/rules binary subprocess returned exit status 2
  make[1]: *** [scripts/Makefile.package:83: bindeb-pkg] Error 2
  make: *** [Makefile:1527: bindeb-pkg] Error 2

The reason is obvious; arch/arc/Makefile sets $(boot)/bootpImage as
the default image, but there is no rule to build it.

Remove the meaningless KBUILD_IMAGE assignment so it will fallback
to the default vmlinux. With this change, you can build the deb package.

I removed the 'bootpImage' target as well. At best, it provides
'make bootpImage' as an alias of 'make vmlinux', but I do not see
much sense in doing so.

Signed-off-by: Masahiro Yamada 
Signed-off-by: Vineet Gupta 
Signed-off-by: Sasha Levin

ARC: stack unwinding: don't assume non-current task is sleeping

2020-12-16T09:56:55+00:00

[ Upstream commit e42404fa10fd11fe72d0a0e149a321d10e577715 ]

To start stack unwinding (SP, PC and BLINK) are needed. When the
explicit execution context (pt_regs etc) is not available, unwinder
assumes the task is sleeping (in __switch_to()) and fetches SP and BLINK
from kernel mode stack.

But this assumption is not true, specially in a SMP system, when top
runs on 1 core, there may be active running processes on all cores.

So when unwinding non courrent tasks, ensure they are NOT running.

And while at it, handle the self unwinding case explicitly.

This came out of investigation of a customer reported hang with
rcutorture+top

Link: https://github.com/foss-for-synopsys-dwc-arc-processors/linux/issues/31
Signed-off-by: Vineet Gupta 
Signed-off-by: Sasha Levin

arch: pgtable: define MAX_POSSIBLE_PHYSMEM_BITS where needed

2020-12-02T07:49:50+00:00

[ Upstream commit cef397038167ac15d085914493d6c86385773709 ]

Stefan Agner reported a bug when using zsram on 32-bit Arm machines
with RAM above the 4GB address boundary:

  Unable to handle kernel NULL pointer dereference at virtual address 00000000
  pgd = a27bd01c
  [00000000] *pgd=236a0003, *pmd=1ffa64003
  Internal error: Oops: 207 [#1] SMP ARM
  Modules linked in: mdio_bcm_unimac(+) brcmfmac cfg80211 brcmutil raspberrypi_hwmon hci_uart crc32_arm_ce bcm2711_thermal phy_generic genet
  CPU: 0 PID: 123 Comm: mkfs.ext4 Not tainted 5.9.6 #1
  Hardware name: BCM2711
  PC is at zs_map_object+0x94/0x338
  LR is at zram_bvec_rw.constprop.0+0x330/0xa64
  pc : []    lr : []    psr: 60000013
  sp : e376bbe0  ip : 00000000  fp : c1e2921c
  r10: 00000002  r9 : c1dda730  r8 : 00000000
  r7 : e8ff7a00  r6 : 00000000  r5 : 02f9ffa0  r4 : e3710000
  r3 : 000fdffe  r2 : c1e0ce80  r1 : ebf979a0  r0 : 00000000
  Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
  Control: 30c5383d  Table: 235c2a80  DAC: fffffffd
  Process mkfs.ext4 (pid: 123, stack limit = 0x495a22e6)
  Stack: (0xe376bbe0 to 0xe376c000)

As it turns out, zsram needs to know the maximum memory size, which
is defined in MAX_PHYSMEM_BITS when CONFIG_SPARSEMEM is set, or in
MAX_POSSIBLE_PHYSMEM_BITS on the x86 architecture.

The same problem will be hit on all 32-bit architectures that have a
physical address space larger than 4GB and happen to not enable sparsemem
and include asm/sparsemem.h from asm/pgtable.h.

After the initial discussion, I suggested just always defining
MAX_POSSIBLE_PHYSMEM_BITS whenever CONFIG_PHYS_ADDR_T_64BIT is
set, or provoking a build error otherwise. This addresses all
configurations that can currently have this runtime bug, but
leaves all other configurations unchanged.

I looked up the possible number of bits in source code and
datasheets, here is what I found:

 - on ARC, CONFIG_ARC_HAS_PAE40 controls whether 32 or 40 bits are used
 - on ARM, CONFIG_LPAE enables 40 bit addressing, without it we never
   support more than 32 bits, even though supersections in theory allow
   up to 40 bits as well.
 - on MIPS, some MIPS32r1 or later chips support 36 bits, and MIPS32r5
   XPA supports up to 60 bits in theory, but 40 bits are more than
   anyone will ever ship
 - On PowerPC, there are three different implementations of 36 bit
   addressing, but 32-bit is used without CONFIG_PTE_64BIT
 - On RISC-V, the normal page table format can support 34 bit
   addressing. There is no highmem support on RISC-V, so anything
   above 2GB is unused, but it might be useful to eventually support
   CONFIG_ZRAM for high pages.

Fixes: 61989a80fb3a ("staging: zsmalloc: zsmalloc memory allocation library")
Fixes: 02390b87a945 ("mm/zsmalloc: Prepare to variable MAX_PHYSMEM_BITS")
Acked-by: Thomas Bogendoerfer 
Reviewed-by: Stefan Agner 
Tested-by: Stefan Agner 
Acked-by: Mike Rapoport 
Link: https://lore.kernel.org/linux-mm/bdfa44bf1c570b05d6c70898e2bbb0acf234ecdf.1604762181.git.stefan@agner.ch/
Signed-off-by: Arnd Bergmann 
Signed-off-by: Sasha Levin

ARC: stack unwinding: avoid indefinite looping

2020-11-10T11:37:33+00:00

commit 328d2168ca524d501fc4b133d6be076142bd305c upstream.

Currently stack unwinder is a while(1) loop which relies on the dwarf
unwinder to signal termination, which in turn relies on dwarf info to do
so. This in theory could cause an infinite loop if the dwarf info was
somehow messed up or the register contents were etc.

This fix thus detects the excessive looping and breaks the loop.

| Mem: 26184K used, 1009136K free, 0K shrd, 0K buff, 14416K cached
| CPU:  0.0% usr 72.8% sys  0.0% nic 27.1% idle  0.0% io  0.0% irq  0.0% sirq
| Load average: 4.33 2.60 1.11 2/74 139
|   PID  PPID USER     STAT   VSZ %VSZ CPU %CPU COMMAND
|   133     2 root     SWN      0  0.0   3 22.9 [rcu_torture_rea]
|   132     2 root     SWN      0  0.0   0 22.0 [rcu_torture_rea]
|   131     2 root     SWN      0  0.0   3 21.5 [rcu_torture_rea]
|   126     2 root     RW       0  0.0   2  5.4 [rcu_torture_wri]
|   129     2 root     SWN      0  0.0   0  0.2 [rcu_torture_fak]
|   137     2 root     SW       0  0.0   0  0.2 [rcu_torture_cbf]
|   127     2 root     SWN      0  0.0   0  0.1 [rcu_torture_fak]
|   138   115 root     R     1464  0.1   2  0.1 top
|   130     2 root     SWN      0  0.0   0  0.1 [rcu_torture_fak]
|   128     2 root     SWN      0  0.0   0  0.1 [rcu_torture_fak]
|   115     1 root     S     1472  0.1   1  0.0 -/bin/sh
|   104     1 root     S     1464  0.1   0  0.0 inetd
|     1     0 root     S     1456  0.1   2  0.0 init
|    78     1 root     S     1456  0.1   0  0.0 syslogd -O /var/log/messages
|   134     2 root     SW       0  0.0   2  0.0 [rcu_torture_sta]
|    10     2 root     IW       0  0.0   1  0.0 [rcu_preempt]
|    88     2 root     IW       0  0.0   1  0.0 [kworker/1:1-eve]
|    66     2 root     IW       0  0.0   2  0.0 [kworker/2:2-eve]
|    39     2 root     IW       0  0.0   2  0.0 [kworker/2:1-eve]
| unwinder looping too long, aborting !

Cc: 
Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman

ARC: perf: redo the pct irq missing in device-tree handling

2020-11-05T10:43:33+00:00

commit 8c42a5c02bec6c7eccf08957be3c6c8fccf9790b upstream.

commit feb92d7d3813456c11dce21 "(ARC: perf: don't bail setup if pct irq
missing in device-tree)" introduced a silly brown-paper bag bug:
The assignment and comparison in an if statement were not bracketed
correctly leaving the order of evaluation undefined.

|
| if (has_interrupts && (irq = platform_get_irq(pdev, 0) >= 0)) {
|                           ^^^                         ^^^^

And given such a chance, the compiler will bite you hard, fully entitled
to generating this piece of beauty:

|
| # if (has_interrupts && (irq = platform_get_irq(pdev, 0) >= 0)) {
|
| bl.d @platform_get_irq  <-- irq returned in r0
|
| setge r2, r0, 0   	<-- r2 is bool 1 or 0 if irq >= 0 true/false
| brlt.d r0, 0, @.L114
|
| st_s	r2,[sp]    	<-- irq saved is bool 1 or 0, not actual return val
| st	1,[r3,160]   	# arc_pmu.18_29->irq <-- drops bool and assumes 1
|
| # return __request_percpu_irq(irq, handler, 0,
|
| bl.d @__request_percpu_irq;
| mov_s	r0,1	   <-- drops even bool and assumes 1 which fails

With the snafu fixed, everything is as expected.

| bl.d @platform_get_irq	<-- returns irq in r0
|
| mov_s	r2,r0
| brlt.d r2, 0, @.L112
|
| st_s	r0,[sp]			<-- irq isaved is actual return value above
| st	r0,[r13,160]	#arc_pmu.18_27->irq
|
| bl.d @__request_percpu_irq	<-- r0 unchanged so actual irq returned
| add r4,r4,r12	#, tmp363, __ptr

Cc: 
Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman

ARC: [dts] fix the errors detected by dtbs_check

2020-11-05T10:43:19+00:00

[ Upstream commit 05b1be68c4d6d76970025e6139bfd735c2256ee5 ]

xxx/arc/boot/dts/axs101.dt.yaml: dw-apb-ictl@e0012000: $nodename:0: \
'dw-apb-ictl@e0012000' does not match '^interrupt-controller(@[0-9a-f,]+)*$'
 From schema: xxx/interrupt-controller/snps,dw-apb-ictl.yaml

The node name of the interrupt controller must start with
"interrupt-controller" instead of "dw-apb-ictl".

Signed-off-by: Zhen Lei 
Signed-off-by: Vineet Gupta 
Signed-off-by: Sasha Levin