linux-stable.git/arch/mips, branch v5.12.2

mips: Do not include hi and lo in clobber list for R6

2021-05-07T10:53:25+00:00

commit 1d7ba0165d8206ac073f7ac3b14fc0836b66eae7 upstream.

From [1]
"GCC 10 (PR 91233) won't silently allow registers that are not
architecturally available to be present in the clobber list anymore,
resulting in build failure for mips*r6 targets in form of:
...
.../sysdep.h:146:2: error: the register ‘lo’ cannot be clobbered in ‘asm’ for the current target
  146 |  __asm__ volatile (      \
      |  ^~~~~~~

This is because base R6 ISA doesn't define hi and lo registers w/o DSP
extension. This patch provides the alternative clobber list for r6 targets
that won't include those registers."

Since kernel 5.4 and mips support for generic vDSO [2], the kernel fail to
build for mips r6 cpus with gcc 10 for the same reason as glibc.

[1] https://sourceware.org/git/?p=glibc.git;a=commit;h=020b2a97bb15f807c0482f0faee2184ed05bcad8
[2] '24640f233b46 ("mips: Add support for generic vDSO")'

Signed-off-by: Romain Naour 
Signed-off-by: Sudip Mukherjee 
Signed-off-by: Thomas Bogendoerfer 
Signed-off-by: Greg Kroah-Hartman

MIPS: kernel: setup.c: fix compilation error

2021-03-30T12:51:23+00:00

With ath79_defconfig enabling CONFIG_MIPS_ELF_APPENDED_DTB gives a
compilation error. This patch fixes it.

Build log:
...
  CC      kernel/locking/percpu-rwsem.o
../arch/mips/kernel/setup.c:46:39: error: conflicting types for
'__appended_dtb'
 const char __section(".appended_dtb") __appended_dtb[0x100000];
                                       ^~~~~~~~~~~~~~
In file included from ../arch/mips/kernel/setup.c:34:
../arch/mips/include/asm/bootinfo.h:118:13: note: previous declaration
of '__appended_dtb' was here
 extern char __appended_dtb[];
             ^~~~~~~~~~~~~~
  CC      fs/attr.o
make[4]: *** [../scripts/Makefile.build:271: arch/mips/kernel/setup.o]
 Error 1
...

Root cause seems to be:
Fixes: b83ba0b9df56 ("MIPS: of: Introduce helper function to get DTB")

Signed-off-by: Mauri Sandberg 
Reviewed-by: Thomas Bogendoerfer 
Cc: trivial@kernel.org
Signed-off-by: Thomas Bogendoerfer

MIPS: vmlinux.lds.S: Fix appended dtb not properly aligned

2021-03-16T21:53:08+00:00

Commit 6654111c893f ("MIPS: vmlinux.lds.S: align raw appended dtb to 8
bytes") changed the alignment from STRUCT_ALIGNMENT bytes to 8 bytes.

The commit's message makes it sound like it was actually done on
purpose, but this is not the case. The commit was written when raw
appended dtb were not aligned at all. The STRUCT_ALIGN() was added a few
days before, in commit 7a05293af39f ("MIPS: boot/compressed: Copy DTB to
aligned address"). The true purpose of the commit was not to align
specifically to 8 bytes, but to make sure that the generated vmlinux'
size was properly padded to the alignment required for DTBs.

While the switch to 8-byte alignment worked for vmlinux-appended dtb
blobs, it broke vmlinuz-appended dtb blobs, as the decompress routine
moves the blob to a STRUCT_ALIGNMENT aligned address.

Fix this by changing the raw appended dtb blob alignment from 8 bytes
back to STRUCT_ALIGNMENT bytes in vmlinux.lds.S.

Fixes: 6654111c893f ("MIPS: vmlinux.lds.S: align raw appended dtb to 8 bytes")
Cc: Bjørn Mork 
Signed-off-by: Paul Cercueil 
Signed-off-by: Thomas Bogendoerfer

MIPS: kernel: Reserve exception base early to prevent corruption

2021-03-09T10:22:59+00:00

BMIPS is one of the few platforms that do change the exception base.
After commit 2dcb39645441 ("memblock: do not start bottom-up allocations
with kernel_end") we started seeing BMIPS boards fail to boot with the
built-in FDT being corrupted.

Before the cited commit, early allocations would be in the [kernel_end,
RAM_END] range, but after commit they would be within [RAM_START +
PAGE_SIZE, RAM_END].

The custom exception base handler that is installed by
bmips_ebase_setup() done for BMIPS5000 CPUs ends-up trampling on the
memory region allocated by unflatten_and_copy_device_tree() thus
corrupting the FDT used by the kernel.

To fix this, we need to perform an early reservation of the custom
exception space. Additional we reserve the first 4k (1k for R3k) for
either normal exception vector space (legacy CPUs) or special vectors
like cache exceptions.

Huge thanks to Serge for analysing and proposing a solution to this
issue.

Fixes: 2dcb39645441 ("memblock: do not start bottom-up allocations with kernel_end")
Reported-by: Kamal Dasu 
Debugged-by: Serge Semin 
Acked-by: Mike Rapoport 
Tested-by: Florian Fainelli 
Reviewed-by: Serge Semin 
Signed-off-by: Thomas Bogendoerfer

MIPS: vmlinux.lds.S: align raw appended dtb to 8 bytes

2021-03-08T17:36:08+00:00

The devicetree specification requires 8-byte alignment in
memory. This is now enforced by libfdt since commit 79edff12060f
("scripts/dtc: Update to upstream version v1.6.0-51-g183df9e9c2b9")
which included the upstream commit 5e735860c478 ("libfdt: Check for
8-byte address alignment in fdt_ro_probe_()").

This broke the MIPS raw appended DTBs which would be appended to
the image immediately following the initramfs section.  This ends
with a 32bit size, resulting in a 4-byte alignment of the DTB.

Fix by padding with zeroes to 8-bytes when MIPS_RAW_APPENDED_DTB
is defined.

Fixes: 79edff12060f ("scripts/dtc: Update to upstream version v1.6.0-51-g183df9e9c2b9")
Cc: Rob Herring 
Cc: Frank Rowand 
Signed-off-by: Bjørn Mork 
Signed-off-by: Thomas Bogendoerfer

crypto: mips/poly1305 - enable for all MIPS processors

2021-03-08T10:52:17+00:00

The MIPS Poly1305 implementation is generic MIPS code written such as to
support down to the original MIPS I and MIPS III ISA for the 32-bit and
64-bit variant respectively.  Lift the current limitation then to enable
code for MIPSr1 ISA or newer processors only and have it available for
all MIPS processors.

Signed-off-by: Maciej W. Rozycki 
Fixes: a11d055e7a64 ("crypto: mips/poly1305 - incorporate OpenSSL/CRYPTOGAMS optimized implementation")
Cc: stable@vger.kernel.org # v5.5+
Acked-by: Jason A. Donenfeld 
Signed-off-by: Thomas Bogendoerfer

MIPS: boot/compressed: Copy DTB to aligned address

2021-03-08T10:49:47+00:00

Since 5.12-rc1, the Device Tree blob must now be properly aligned.

Therefore, the decompress routine must be careful to copy the blob at
the next aligned address after the kernel image.

This commit fixes the kernel sometimes not booting with a Device Tree
blob appended to it.

Fixes: 79edff12060f ("scripts/dtc: Update to upstream version v1.6.0-51-g183df9e9c2b9")
Signed-off-by: Paul Cercueil 
Acked-by: Rob Herring 
Signed-off-by: Thomas Bogendoerfer

Merge tag 'io_uring-worker.v3-2021-02-25' of git://git.kernel.dk/linux-block

2021-02-27T16:29:02+00:00

Pull io_uring thread rewrite from Jens Axboe:
 "This converts the io-wq workers to be forked off the tasks in question
  instead of being kernel threads that assume various bits of the
  original task identity.

  This kills > 400 lines of code from io_uring/io-wq, and it's the worst
  part of the code. We've had several bugs in this area, and the worry
  is always that we could be missing some pieces for file types doing
  unusual things (recent /dev/tty example comes to mind, userfaultfd
  reads installing file descriptors is another fun one... - both of
  which need special handling, and I bet it's not the last weird oddity
  we'll find).

  With these identical workers, we can have full confidence that we're
  never missing anything. That, in itself, is a huge win. Outside of
  that, it's also more efficient since we're not wasting space and code
  on tracking state, or switching between different states.

  I'm sure we're going to find little things to patch up after this
  series, but testing has been pretty thorough, from the usual
  regression suite to production. Any issue that may crop up should be
  manageable.

  There's also a nice series of further reductions we can do on top of
  this, but I wanted to get the meat of it out sooner rather than later.
  The general worry here isn't that it's fundamentally broken. Most of
  the little issues we've found over the last week have been related to
  just changes in how thread startup/exit is done, since that's the main
  difference between using kthreads and these kinds of threads. In fact,
  if all goes according to plan, I want to get this into the 5.10 and
  5.11 stable branches as well.

  That said, the changes outside of io_uring/io-wq are:

   - arch setup, simple one-liner to each arch copy_thread()
     implementation.

   - Removal of net and proc restrictions for io_uring, they are no
     longer needed or useful"

* tag 'io_uring-worker.v3-2021-02-25' of git://git.kernel.dk/linux-block: (30 commits)
  io-wq: remove now unused IO_WQ_BIT_ERROR
  io_uring: fix SQPOLL thread handling over exec
  io-wq: improve manager/worker handling over exec
  io_uring: ensure SQPOLL startup is triggered before error shutdown
  io-wq: make buffered file write hashed work map per-ctx
  io-wq: fix race around io_worker grabbing
  io-wq: fix races around manager/worker creation and task exit
  io_uring: ensure io-wq context is always destroyed for tasks
  arch: ensure parisc/powerpc handle PF_IO_WORKER in copy_thread()
  io_uring: cleanup ->user usage
  io-wq: remove nr_process accounting
  io_uring: flag new native workers with IORING_FEAT_NATIVE_WORKERS
  net: remove cmsg restriction from io_uring based send/recvmsg calls
  Revert "proc: don't allow async path resolution of /proc/self components"
  Revert "proc: don't allow async path resolution of /proc/thread-self components"
  io_uring: move SQPOLL thread io-wq forked worker
  io-wq: make io_wq_fork_thread() available to other users
  io-wq: only remove worker from free_list, if it was there
  io_uring: remove io_identity
  io_uring: remove any grabbing of context
  ...

Merge branch 'akpm' (patches from Andrew)

2021-02-26T17:50:09+00:00

Merge more updates from Andrew Morton:
 "118 patches:

   - The rest of MM.

     Includes kfence - another runtime memory validator. Not as thorough
     as KASAN, but it has unmeasurable overhead and is intended to be
     usable in production builds.

   - Everything else

  Subsystems affected by this patch series: alpha, procfs, sysctl,
  misc, core-kernel, MAINTAINERS, lib, bitops, checkpatch, init,
  coredump, seq_file, gdb, ubsan, initramfs, and mm (thp, cma,
  vmstat, memory-hotplug, mlock, rmap, zswap, zsmalloc, cleanups,
  kfence, kasan2, and pagemap2)"

* emailed patches from Andrew Morton : (118 commits)
  MIPS: make userspace mapping young by default
  initramfs: panic with memory information
  ubsan: remove overflow checks
  kgdb: fix to kill breakpoints on initmem after boot
  scripts/gdb: fix list_for_each
  x86: fix seq_file iteration for pat/memtype.c
  seq_file: document how per-entry resources are managed.
  fs/coredump: use kmap_local_page()
  init/Kconfig: fix a typo in CC_VERSION_TEXT help text
  init: clean up early_param_on_off() macro
  init/version.c: remove Version_ symbol
  checkpatch: do not apply "initialise globals to 0" check to BPF progs
  checkpatch: don't warn about colon termination in linker scripts
  checkpatch: add kmalloc_array_node to unnecessary OOM message check
  checkpatch: add warning for avoiding .L prefix symbols in assembly files
  checkpatch: improve TYPECAST_INT_CONSTANT test message
  checkpatch: prefer ftrace over function entry/exit printks
  checkpatch: trivial style fixes
  checkpatch: ignore warning designated initializers using NR_CPUS
  checkpatch: improve blank line after declaration test
  ...

MIPS: make userspace mapping young by default

2021-02-26T17:41:05+00:00

MIPS page fault path(except huge page) takes 3 exceptions (1 TLB Miss + 2
TLB Invalid), butthe second TLB Invalid exception is just triggered by
__update_tlb from do_page_fault writing tlb without _PAGE_VALID set.  With
this patch, user space mapping prot is made young by default (with both
_PAGE_VALID and _PAGE_YOUNG set), and it only take 1 TLB Miss + 1 TLB
Invalid exception

Remove pte_sw_mkyoung without polluting MM code and make page fault delay
of MIPS on par with other architecture

Link: https://lkml.kernel.org/r/20210204013942.8398-1-huangpei@loongson.cn
Signed-off-by: Huang Pei 
Reviewed-by: Nicholas Piggin 
Acked-by: 
Acked-by: Thomas Bogendoerfer 
Cc: Christophe Leroy 
Cc: 
Cc: Bibo Mao 
Cc: Jiaxun Yang 
Cc: Paul Burton 
Cc: Li Xuefeng 
Cc: Yang Tiezhu 
Cc: Gao Juxin 
Cc: Fuxin Zhang 
Cc: Huacai Chen 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds