linux-stable.git/arch, branch v3.18.129

powerpc/vdso64: Use double word compare on pointers

2018-12-13T08:22:31+00:00

[ Upstream commit 5045ea37377ce8cca6890d32b127ad6770e6dce5 ]

__kernel_get_syscall_map() and __kernel_clock_getres() use cmpli to
check if the passed in pointer is non zero. cmpli maps to a 32 bit
compare on binutils, so we ignore the top 32 bits.

A simple test case can be created by passing in a bogus pointer with
the bottom 32 bits clear. Using a clk_id that is handled by the VDSO,
then one that is handled by the kernel shows the problem:

  printf("%d\n", clock_getres(CLOCK_REALTIME, (void *)0x100000000));
  printf("%d\n", clock_getres(CLOCK_BOOTTIME, (void *)0x100000000));

And we get:

  0
  -1

The bigger issue is if we pass a valid pointer with the bottom 32 bits
clear, in this case we will return success but won't write any data
to the pointer.

I stumbled across this issue because the LLVM integrated assembler
doesn't accept cmpli with 3 arguments. Fix this by converting them to
cmpldi.

Fixes: a7f290dad32e ("[PATCH] powerpc: Merge vdso's and add vdso support to 32 bits kernel")
Cc: stable@vger.kernel.org # v2.6.15+
Signed-off-by: Anton Blanchard 
Signed-off-by: Michael Ellerman 
Signed-off-by: Sasha Levin

mips: fix mips_get_syscall_arg o32 check

2018-12-13T08:22:29+00:00

commit c50cbd85cd7027d32ac5945bb60217936b4f7eaf upstream.

When checking for TIF_32BIT_REGS flag, mips_get_syscall_arg() should
use the task specified as its argument instead of the current task.

This potentially affects all syscall_get_arguments() users
who specify tasks different from the current.

Fixes: c0ff3c53d4f99 ("MIPS: Enable HAVE_ARCH_TRACEHOOK.")
Signed-off-by: Dmitry V. Levin 
Signed-off-by: Paul Burton 
Patchwork: https://patchwork.linux-mips.org/patch/21185/
Cc: Elvira Khabirova 
Cc: Ralf Baechle 
Cc: James Hogan 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org # v3.13+
Signed-off-by: Greg Kroah-Hartman

arm64: remove no-op -p linker flag

2018-12-01T08:48:00+00:00

(commit 1a381d4a0a9a0f999a13faaba22bf6b3fc80dcb9 upstream)

Linking the ARM64 defconfig kernel with LLVM lld fails with the error:

  ld.lld: error: unknown argument: -p
  Makefile:1015: recipe for target 'vmlinux' failed

Without this flag, the ARM64 defconfig kernel successfully links with
lld and boots on Dragonboard 410c.

After digging through binutils source and changelogs, it turns out that
-p is only relevant to ancient binutils installations targeting 32-bit
ARM.  binutils accepts -p for AArch64 too, but it's always been
undocumented and silently ignored.  A comment in
ld/emultempl/aarch64elf.em explains that it's "Only here for backwards
compatibility".

Since this flag is a no-op on ARM64, we can safely drop it.

Acked-by: Will Deacon 
Reviewed-by: Nick Desaulniers 
Signed-off-by: Greg Hackmann 
Signed-off-by: Catalin Marinas 
Signed-off-by: Nick Desaulniers 
Signed-off-by: Sasha Levin

powerpc/numa: Suppress "VPHN is not supported" messages

2018-12-01T08:47:59+00:00

[ Upstream commit 437ccdc8ce629470babdda1a7086e2f477048cbd ]

When VPHN function is not supported and during cpu hotplug event,
kernel prints message 'VPHN function not supported. Disabling
polling...'. Currently it prints on every hotplug event, it floods
dmesg when a KVM guest tries to hotplug huge number of vcpus, let's
just print once and suppress further kernel prints.

Signed-off-by: Satheesh Rajendran 
Signed-off-by: Michael Ellerman 
Signed-off-by: Sasha Levin

s390/vdso: add missing FORCE to build targets

2018-11-27T15:05:36+00:00

[ Upstream commit b44b136a3773d8a9c7853f8df716bd1483613cbb ]

According to Documentation/kbuild/makefiles.txt all build targets using
if_changed should use FORCE as well. Add missing FORCE to make sure
vdso targets are rebuild properly when not just immediate prerequisites
have changed but also when build command differs.

Reviewed-by: Philipp Rudo 
Signed-off-by: Vasily Gorbik 
Signed-off-by: Martin Schwidefsky 
Signed-off-by: Sasha Levin

um: Give start_idle_thread() a return code

2018-11-27T15:05:36+00:00

[ Upstream commit 7ff1e34bbdc15acab823b1ee4240e94623d50ee8 ]

Fixes:
arch/um/os-Linux/skas/process.c:613:1: warning: control reaches end of
non-void function [-Wreturn-type]

longjmp() never returns but gcc still warns that the end of the function
can be reached.
Add a return code and debug aid to detect this impossible case.

Signed-off-by: Richard Weinberger 
Signed-off-by: Sasha Levin

arch/alpha, termios: implement BOTHER, IBSHIFT and termios2

2018-11-22T06:32:47+00:00

commit d0ffb805b729322626639336986bc83fc2e60871 upstream.

Alpha has had c_ispeed and c_ospeed, but still set speeds in c_cflags
using arbitrary flags. Because BOTHER is not defined, the general
Linux code doesn't allow setting arbitrary baud rates, and because
CBAUDEX == 0, we can have an array overrun of the baud_rate[] table in
drivers/tty/tty_baudrate.c if (c_cflags & CBAUD) == 037.

Resolve both problems by #defining BOTHER to 037 on Alpha.

However, userspace still needs to know if setting BOTHER is actually
safe given legacy kernels (does anyone actually care about that on
Alpha anymore?), so enable the TCGETS2/TCSETS*2 ioctls on Alpha, even
though they use the same structure. Define struct termios2 just for
compatibility; it is the exact same structure as struct termios. In a
future patchset, this will be cleaned up so the uapi headers are
usable from libc.

Signed-off-by: H. Peter Anvin (Intel) 
Cc: Jiri Slaby 
Cc: Al Viro 
Cc: Richard Henderson 
Cc: Ivan Kokshaysky 
Cc: Matt Turner 
Cc: Thomas Gleixner 
Cc: Kate Stewart 
Cc: Philippe Ombredanne 
Cc: Eugene Syromiatnikov 
Cc: 
Cc: 
Cc: Johan Hovold 
Cc: Alan Cox 
Cc: 
Signed-off-by: Greg Kroah-Hartman

xtensa: fix boot parameters address translation

2018-11-22T06:32:46+00:00

commit 40dc948f234b73497c3278875eb08a01d5854d3f upstream.

The bootloader may pass physical address of the boot parameters structure
to the MMUv3 kernel in the register a2. Code in the _SetupMMU block in
the arch/xtensa/kernel/head.S is supposed to map that physical address to
the virtual address in the configured virtual memory layout.

This code haven't been updated when additional 256+256 and 512+512
memory layouts were introduced and it may produce wrong addresses when
used with these layouts.

Cc: stable@vger.kernel.org
Signed-off-by: Max Filippov 
Signed-off-by: Greg Kroah-Hartman

powerpc/boot: Ensure _zimage_start is a weak symbol

2018-11-22T06:32:46+00:00

[ Upstream commit ee9d21b3b3583712029a0db65a4b7c081d08d3b3 ]

When building with clang crt0's _zimage_start is not marked weak, which
breaks the build when linking the kernel image:

 $ objdump -t arch/powerpc/boot/crt0.o |grep _zimage_start$
 0000000000000058 g       .text  0000000000000000 _zimage_start

 ld: arch/powerpc/boot/wrapper.a(crt0.o): in function '_zimage_start':
 (.text+0x58): multiple definition of '_zimage_start';
 arch/powerpc/boot/pseries-head.o:(.text+0x0): first defined here

Clang requires the .weak directive to appear after the symbol is
declared. The binutils manual says:

 This directive sets the weak attribute on the comma separated list of
 symbol names. If the symbols do not already exist, they will be
 created.

So it appears this is different with clang. The only reference I could
see for this was an OpenBSD mailing list post[1].

Changing it to be after the declaration fixes building with Clang, and
still works with GCC.

 $ objdump -t arch/powerpc/boot/crt0.o |grep _zimage_start$
 0000000000000058  w      .text	0000000000000000 _zimage_start

Reported to clang as https://bugs.llvm.org/show_bug.cgi?id=38921

[1] https://groups.google.com/forum/#!topic/fa.openbsd.tech/PAgKKen2YCY

Signed-off-by: Joel Stanley 
Reviewed-by: Nick Desaulniers 
Signed-off-by: Michael Ellerman 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

MIPS: kexec: Mark CPU offline before disabling local IRQ

2018-11-22T06:32:46+00:00

[ Upstream commit dc57aaf95a516f70e2d527d8287a0332c481a226 ]

After changing CPU online status, it will not be sent any IPIs such as in
__flush_cache_all() on software coherency systems. Do this before disabling
local IRQ.

Signed-off-by: Dengcheng Zhu 
Signed-off-by: Paul Burton 
Patchwork: https://patchwork.linux-mips.org/patch/20571/
Cc: pburton@wavecomp.com
Cc: ralf@linux-mips.org
Cc: linux-mips@linux-mips.org
Cc: rachel.mozes@intel.com
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman