linux.git/lib, branch v5.9-rc2

lib/string.c: Use freestanding environment

2020-08-19T18:23:45+00:00

gcc can transform the loop in a naive implementation of memset/memcpy
etc into a call to the function itself.  This optimization is enabled by
-ftree-loop-distribute-patterns.

This has been the case for a while, but gcc-10.x enables this option at
-O2 rather than -O3 as in previous versions.

Add -ffreestanding, which implicitly disables this optimization with
gcc.  It is unclear whether clang performs such optimizations, but
hopefully it will also not do so in a freestanding environment.

Signed-off-by: Arvind Sankar 
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56888
Signed-off-by: Linus Torvalds

iomap: constify ioreadX() iomem argument (as in generic implementation)

2020-08-15T02:56:57+00:00

Patch series "iomap: Constify ioreadX() iomem argument", v3.

The ioread8/16/32() and others have inconsistent interface among the
architectures: some taking address as const, some not.

It seems there is nothing really stopping all of them to take pointer to
const.

This patch (of 4):

The ioreadX() and ioreadX_rep() helpers have inconsistent interface.  On
some architectures void *__iomem address argument is a pointer to const,
on some not.

Implementations of ioreadX() do not modify the memory under the address so
they can be converted to a "const" version for const-safety and
consistency among architectures.

[krzk@kernel.org: sh: clk: fix assignment from incompatible pointer type for ioreadX()]
  Link: http://lkml.kernel.org/r/20200723082017.24053-1-krzk@kernel.org
[akpm@linux-foundation.org: fix drivers/mailbox/bcm-pdc-mailbox.c]
  Link: http://lkml.kernel.org/r/202007132209.Rxmv4QyS%25lkp@intel.com

Suggested-by: Geert Uytterhoeven 
Signed-off-by: Krzysztof Kozlowski 
Signed-off-by: Andrew Morton 
Reviewed-by: Geert Uytterhoeven 
Reviewed-by: Arnd Bergmann 
Cc: Richard Henderson 
Cc: Ivan Kokshaysky 
Cc: Matt Turner 
Cc: "James E.J. Bottomley" 
Cc: Helge Deller 
Cc: Michael Ellerman 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: Yoshinori Sato 
Cc: Rich Felker 
Cc: Kalle Valo 
Cc: "David S. Miller" 
Cc: Jakub Kicinski 
Cc: Dave Jiang 
Cc: Jon Mason 
Cc: Allen Hubbe 
Cc: "Michael S. Tsirkin" 
Cc: Jason Wang 
Link: http://lkml.kernel.org/r/20200709072837.5869-1-krzk@kernel.org
Link: http://lkml.kernel.org/r/20200709072837.5869-2-krzk@kernel.org
Signed-off-by: Linus Torvalds

lz4: fix kernel decompression speed

2020-08-15T02:56:56+00:00

This patch replaces all memcpy() calls with LZ4_memcpy() which calls
__builtin_memcpy() so the compiler can inline it.

LZ4 relies heavily on memcpy() with a constant size being inlined.  In x86
and i386 pre-boot environments memcpy() cannot be inlined because memcpy()
doesn't get defined as __builtin_memcpy().

An equivalent patch has been applied upstream so that the next import
won't lose this change [1].

I've measured the kernel decompression speed using QEMU before and after
this patch for the x86_64 and i386 architectures.  The speed-up is about
10x as shown below.

Code	Arch	Kernel Size	Time	Speed
v5.8	x86_64	11504832 B	148 ms	 79 MB/s
patch	x86_64	11503872 B	 13 ms	885 MB/s
v5.8	i386	 9621216 B	 91 ms	106 MB/s
patch	i386	 9620224 B	 10 ms	962 MB/s

I also measured the time to decompress the initramfs on x86_64, i386, and
arm.  All three show the same decompression speed before and after, as
expected.

[1] https://github.com/lz4/lz4/pull/890

Signed-off-by: Nick Terrell 
Signed-off-by: Andrew Morton 
Cc: Yann Collet 
Cc: Gao Xiang 
Cc: Sven Schmidt <4sschmid@informatik.uni-hamburg.de>
Cc: Greg Kroah-Hartman 
Cc: Ingo Molnar 
Cc: Arvind Sankar 
Link: http://lkml.kernel.org/r/20200803194022.2966806-1-nickrterrell@gmail.com
Signed-off-by: Linus Torvalds

Merge tag 'timers-urgent-2020-08-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2020-08-14T21:26:08+00:00

Pull timekeeping updates from Thomas Gleixner:
 "A set of timekeeping/VDSO updates:

   - Preparatory work to allow S390 to switch over to the generic VDSO
     implementation.

     S390 requires that the VDSO data pointer is handed in to the
     counter read function when time namespace support is enabled.
     Adding the pointer is a NOOP for all other architectures because
     the compiler is supposed to optimize that out when it is unused in
     the architecture specific inline. The change also solved a similar
     problem for MIPS which fortunately has time namespaces not yet
     enabled.

     S390 needs to update clock related VDSO data independent of the
     timekeeping updates. This was solved so far with yet another
     sequence counter in the S390 implementation. A better solution is
     to utilize the already existing VDSO sequence count for this. The
     core code now exposes helper functions which allow to serialize
     against the timekeeper code and against concurrent readers.

     S390 needs extra data for their clock readout function. The initial
     common VDSO data structure did not provide a way to add that. It
     now has an embedded architecture specific struct embedded which
     defaults to an empty struct.

     Doing this now avoids tree dependencies and conflicts post rc1 and
     allows all other architectures which work on generic VDSO support
     to work from a common upstream base.

   - A trivial comment fix"

* tag 'timers-urgent-2020-08-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  time: Delete repeated words in comments
  lib/vdso: Allow to add architecture-specific vdso data
  timekeeping/vsyscall: Provide vdso_update_begin/end()
  vdso/treewide: Add vdso_data pointer argument to __arch_get_hw_counter()

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2020-08-14T03:03:11+00:00

Pull networking fixes from David Miller:
 "Some merge window fallout, some longer term fixes:

   1) Handle headroom properly in lapbether and x25_asy drivers, from
      Xie He.

   2) Fetch MAC address from correct r8152 device node, from Thierry
      Reding.

   3) In the sw kTLS path we should allow MSG_CMSG_COMPAT in sendmsg,
      from Rouven Czerwinski.

   4) Correct fdputs in socket layer, from Miaohe Lin.

   5) Revert troublesome sockptr_t optimization, from Christoph Hellwig.

   6) Fix TCP TFO key reading on big endian, from Jason Baron.

   7) Missing CAP_NET_RAW check in nfc, from Qingyu Li.

   8) Fix inet fastreuse optimization with tproxy sockets, from Tim
      Froidcoeur.

   9) Fix 64-bit divide in new SFC driver, from Edward Cree.

  10) Add a tracepoint for prandom_u32 so that we can more easily
      perform usage analysis. From Eric Dumazet.

  11) Fix rwlock imbalance in AF_PACKET, from John Ogness"

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (49 commits)
  net: openvswitch: introduce common code for flushing flows
  af_packet: TPACKET_V3: fix fill status rwlock imbalance
  random32: add a tracepoint for prandom_u32()
  Revert "ipv4: tunnel: fix compilation on ARCH=um"
  net: accept an empty mask in /sys/class/net/*/queues/rx-*/rps_cpus
  net: ethernet: stmmac: Disable hardware multicast filter
  net: stmmac: dwmac1000: provide multicast filter fallback
  ipv4: tunnel: fix compilation on ARCH=um
  vsock: fix potential null pointer dereference in vsock_poll()
  sfc: fix ef100 design-param checking
  net: initialize fastreuse on inet_inherit_port
  net: refactor bind_bucket fastreuse into helper
  net: phy: marvell10g: fix null pointer dereference
  net: Fix potential memory leak in proto_register()
  net: qcom/emac: add missed clk_disable_unprepare in error path of emac_clks_phase1_init
  ionic_lif: Use devm_kcalloc() in ionic_qcq_alloc()
  net/nfc/rawsock.c: add CAP_NET_RAW check.
  hinic: fix strncpy output truncated compile warnings
  drivers/net/wan/x25_asy: Added needed_headroom and a skb->len check
  net/tls: Fix kmap usage
  ...

random32: add a tracepoint for prandom_u32()

2020-08-13T22:11:14+00:00

There has been some heat around prandom_u32() lately, and some people
were wondering if there was a simple way to determine how often
it was used, before considering making it maybe 10 times more expensive.

This tracepoint exports the generated pseudo random value.

Tested:

perf list | grep prandom_u32
  random:prandom_u32                                 [Tracepoint event]

perf record -a [-g] [-C1] -e random:prandom_u32 sleep 1
[ perf record: Woken up 0 times to write data ]
[ perf record: Captured and wrote 259.748 MB perf.data (924087 samples) ]

perf report --nochildren
    ...
    97.67%  ksoftirqd/1     [kernel.vmlinux]  [k] prandom_u32
            |
            ---prandom_u32
               prandom_u32
               |
               |--48.86%--tcp_v4_syn_recv_sock
               |          tcp_check_req
               |          tcp_v4_rcv
               |          ...
                --48.81%--tcp_conn_request
                          tcp_v4_conn_request
                          tcp_rcv_state_process
                          ...
perf script

Signed-off-by: Eric Dumazet 
Cc: Willy Tarreau 
Cc: Sedat Dilek 
Tested-by: Sedat Dilek 
Signed-off-by: David S. Miller

lib/Kconfig.debug: fix typo in the help text of CONFIG_PANIC_TIMEOUT

2020-08-12T17:58:02+00:00

There exists duplicated "the" in the help text of CONFIG_PANIC_TIMEOUT,
Remove it.

Signed-off-by: Tiezhu Yang 
Signed-off-by: Andrew Morton 
Reviewed-by: Kees Cook 
Cc: Xuefeng Li 
Link: http://lkml.kernel.org/r/1591103358-32087-2-git-send-email-yangtiezhu@loongson.cn
Signed-off-by: Linus Torvalds

test_kmod: avoid potential double free in trigger_config_run_type()

2020-08-12T17:58:01+00:00

Reset the member "test_fs" of the test configuration after a call of the
function "kfree_const" to a null pointer so that a double memory release
will not be performed.

Fixes: d9c6a72d6fa2 ("kmod: add test driver to stress test the module loader")
Signed-off-by: Tiezhu Yang 
Signed-off-by: Luis Chamberlain 
Signed-off-by: Andrew Morton 
Acked-by: Luis Chamberlain 
Cc: Alexei Starovoitov 
Cc: Al Viro 
Cc: Christian Brauner 
Cc: Chuck Lever 
Cc: David Howells 
Cc: David S. Miller 
Cc: Greg Kroah-Hartman 
Cc: Jakub Kicinski 
Cc: James Morris 
Cc: Jarkko Sakkinen 
Cc: J. Bruce Fields 
Cc: Jens Axboe 
Cc: Josh Triplett 
Cc: Kees Cook 
Cc: Lars Ellenberg 
Cc: Nikolay Aleksandrov 
Cc: Philipp Reisner 
Cc: Roopa Prabhu 
Cc: "Serge E. Hallyn" 
Cc: Sergei Trofimovich 
Cc: Sergey Kvachonok 
Cc: Shuah Khan 
Cc: Tony Vroon 
Cc: Christoph Hellwig 
Link: http://lkml.kernel.org/r/20200610154923.27510-4-mcgrof@kernel.org
Signed-off-by: Linus Torvalds

lib/test_bits.c: add tests of GENMASK

2020-08-12T17:58:00+00:00

Add tests of GENMASK and GENMASK_ULL.

A few test cases that should fail compilation are provided under #ifdef
TEST_GENMASK_FAILURES

[rd.dunlap@gmail.com: add MODULE_LICENSE()]
  Link: http://lkml.kernel.org/r/dfc74524-0789-2827-4eff-476ddab65699@gmail.com
[weiyongjun1@huawei.com: make some functions static]
  Link: http://lkml.kernel.org/r/20200702150336.4756-1-weiyongjun1@huawei.com

Suggested-by: Andy Shevchenko 
Signed-off-by: Rikard Falkeborn 
Signed-off-by: Randy Dunlap 
Signed-off-by: Wei Yongjun 
Signed-off-by: Andrew Morton 
Reviewed-by: Andy Shevchenko 
Acked-by: William Breathitt Gray 
Cc: Emil Velikov 
Cc: Syed Nayyar Waris 
Cc: Andy Shevchenko 
Cc: Arnd Bergmann 
Cc: Geert Uytterhoeven 
Cc: Kees Cook 
Cc: Linus Walleij 
Cc: Masahiro Yamada 
Link: http://lkml.kernel.org/r/20200621054210.14804-2-rikard.falkeborn@gmail.com
Link: http://lkml.kernel.org/r/20200608221823.35799-2-rikard.falkeborn@gmail.com
Signed-off-by: Linus Torvalds

kstrto: do not describe simple_strto() as obsolete/replaced