linux-stable.git/arch/mips/include, branch v4.9.232

KVM: MIPS: Fix VPN2_MASK definition for variable cpu_vmbits

2020-06-20T08:24:12+00:00

commit 5816c76dea116a458f1932eefe064e35403248eb upstream.

If a CPU support more than 32bit vmbits (which is true for 64bit CPUs),
VPN2_MASK set to fixed 0xffffe000 will lead to a wrong EntryHi in some
functions such as _kvm_mips_host_tlb_inv().

The cpu_vmbits definition of 32bit CPU in cpu-features.h is 31, so we
still use the old definition.

Cc: Stable 
Reviewed-by: Aleksandar Markovic 
Signed-off-by: Xing Li 
[Huacai: Improve commit messages]
Signed-off-by: Huacai Chen 
Message-Id: <1590220602-3547-3-git-send-email-chenhc@lemote.com>
Signed-off-by: Paolo Bonzini 
Signed-off-by: Greg Kroah-Hartman

KVM: MIPS: Define KVM_ENTRYHI_ASID to cpu_asid_mask(&boot_cpu_data)

2020-06-20T08:24:11+00:00

commit fe2b73dba47fb6d6922df1ad44e83b1754d5ed4d upstream.

The code in decode_config4() of arch/mips/kernel/cpu-probe.c

        asid_mask = MIPS_ENTRYHI_ASID;
        if (config4 & MIPS_CONF4_AE)
                asid_mask |= MIPS_ENTRYHI_ASIDX;
        set_cpu_asid_mask(c, asid_mask);

set asid_mask to cpuinfo->asid_mask.

So in order to support variable ASID_MASK, KVM_ENTRYHI_ASID should also
be changed to cpu_asid_mask(&boot_cpu_data).

Cc: Stable   #4.9+
Reviewed-by: Aleksandar Markovic 
Signed-off-by: Xing Li 
[Huacai: Change current_cpu_data to boot_cpu_data for optimization]
Signed-off-by: Huacai Chen 
Message-Id: <1590220602-3547-2-git-send-email-chenhc@lemote.com>
Signed-off-by: Paolo Bonzini 
Signed-off-by: Greg Kroah-Hartman

mips: avoid explicit UB in assignment of mips_io_port_base

2020-01-29T09:24:30+00:00

[ Upstream commit 12051b318bc3ce5b42d6d786191008284b067d83 ]

The code in question is modifying a variable declared const through
pointer manipulation.  Such code is explicitly undefined behavior, and
is the lone issue preventing malta_defconfig from booting when built
with Clang:

If an attempt is made to modify an object defined with a const-qualified
type through use of an lvalue with non-const-qualified type, the
behavior is undefined.

LLVM is removing such assignments. A simple fix is to not declare
variables const that you plan on modifying.  Limiting the scope would be
a better method of preventing unwanted writes to such a variable.

Further, the code in question mentions "compiler bugs" without any links
to bug reports, so it is difficult to know if the issue is resolved in
GCC. The patch was authored in 2006, which would have been GCC 4.0.3 or
4.1.1. The minimal supported version of GCC in the Linux kernel is
currently 4.6.

For what its worth, there was UB before the commit in question, it just
added a barrier and got lucky IRT codegen. I don't think there's any
actual compiler bugs related, just runtime bugs due to UB.

Link: https://github.com/ClangBuiltLinux/linux/issues/610
Fixes: 966f4406d903 ("[MIPS] Work around bad code generation for .")
Reported-by: Nathan Chancellor 
Debugged-by: Nathan Chancellor 
Suggested-by: Eli Friedman 
Signed-off-by: Nick Desaulniers 
Reviewed-by: Nathan Chancellor 
Tested-by: Nathan Chancellor 
Signed-off-by: Paul Burton 
Cc: ralf@linux-mips.org
Cc: jhogan@kernel.org
Cc: Maciej W. Rozycki 
Cc: Hassan Naveed 
Cc: Stephen Kitt 
Cc: Serge Semin 
Cc: Mike Rapoport 
Cc: Andrew Morton 
Cc: Michal Hocko 
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: clang-built-linux@googlegroups.com
Signed-off-by: Sasha Levin

MIPS: Avoid VDSO ABI breakage due to global register variable

2020-01-12T10:24:12+00:00

commit bbcc5672b0063b0e9d65dc8787a4f09c3b5bb5cc upstream.

Declaring __current_thread_info as a global register variable has the
effect of preventing GCC from saving & restoring its value in cases
where the ABI would typically do so.

To quote GCC documentation:

> If the register is a call-saved register, call ABI is affected: the
> register will not be restored in function epilogue sequences after the
> variable has been assigned. Therefore, functions cannot safely return
> to callers that assume standard ABI.

When our position independent VDSO is built for the n32 or n64 ABIs all
functions it exposes should be preserving the value of $gp/$28 for their
caller, but in the presence of the __current_thread_info global register
variable GCC stops doing so & simply clobbers $gp/$28 when calculating
the address of the GOT.

In cases where the VDSO returns success this problem will typically be
masked by the caller in libc returning & restoring $gp/$28 itself, but
that is by no means guaranteed. In cases where the VDSO returns an error
libc will typically contain a fallback path which will now fail
(typically with a bad memory access) if it attempts anything which
relies upon the value of $gp/$28 - eg. accessing anything via the GOT.

One fix for this would be to move the declaration of
__current_thread_info inside the current_thread_info() function,
demoting it from global register variable to local register variable &
avoiding inadvertently creating a non-standard calling ABI for the VDSO.
Unfortunately this causes issues for clang, which doesn't support local
register variables as pointed out by commit fe92da0f355e ("MIPS: Changed
current_thread_info() to an equivalent supported by both clang and GCC")
which introduced the global register variable before we had a VDSO to
worry about.

Instead, fix this by continuing to use the global register variable for
the kernel proper but declare __current_thread_info as a simple extern
variable when building the VDSO. It should never be referenced, and will
cause a link error if it is. This resolves the calling convention issue
for the VDSO without having any impact upon the build of the kernel
itself for either clang or gcc.

Signed-off-by: Paul Burton 
Fixes: ebb5e78cc634 ("MIPS: Initial implementation of a VDSO")
Reported-by: Jason A. Donenfeld 
Reviewed-by: Jason A. Donenfeld 
Tested-by: Jason A. Donenfeld 
Cc: Arnd Bergmann 
Cc: Christian Brauner 
Cc: Vincenzo Frascino 
Cc:  # v4.4+
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

MIPS: OCTEON: cvmx_pko_mem_debug8: use oldest forward compatible definition

2019-12-21T09:41:23+00:00

[ Upstream commit 1c6121c39677175bd372076020948e184bad4b6b ]

cn58xx is compatible with cn50xx, so use the latter.

Signed-off-by: Aaro Koskinen 
[paul.burton@mips.com: s/cn52xx/cn50xx/ in commit message.]
Signed-off-by: Paul Burton 
Cc: Ralf Baechle 
Cc: James Hogan 
Cc: linux-mips@vger.kernel.org
Signed-off-by: Sasha Levin

MIPS: kexec: Relax memory restriction

2019-11-25T08:52:47+00:00

[ Upstream commit a6da4d6fdf8bd512c98d3ac7f1d16bc4bb282919 ]

We can rely on the system kernel and the dump capture kernel themselves in
memory usage.

Being restrictive with 512MB limit may cause kexec tool failure on some
platforms.

Tested-by: Rachel Mozes 
Reported-by: Rachel Mozes 
Signed-off-by: Dengcheng Zhu 
Signed-off-by: Paul Burton 
Patchwork: https://patchwork.linux-mips.org/patch/20568/
Cc: pburton@wavecomp.com
Cc: ralf@linux-mips.org
Cc: linux-mips@linux-mips.org
Signed-off-by: Sasha Levin

MIPS: bmips: mark exception vectors as char arrays

2019-11-10T10:23:21+00:00

[ Upstream commit e4f5cb1a9b27c0f94ef4f5a0178a3fde2d3d0e9e ]

The vectors span more than one byte, so mark them as arrays.

Fixes the following build error when building when using GCC 8.3:

In file included from ./include/linux/string.h:19,
                 from ./include/linux/bitmap.h:9,
                 from ./include/linux/cpumask.h:12,
                 from ./arch/mips/include/asm/processor.h:15,
                 from ./arch/mips/include/asm/thread_info.h:16,
                 from ./include/linux/thread_info.h:38,
                 from ./include/asm-generic/preempt.h:5,
                 from ./arch/mips/include/generated/asm/preempt.h:1,
                 from ./include/linux/preempt.h:81,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/mmzone.h:8,
                 from ./include/linux/bootmem.h:8,
                 from arch/mips/bcm63xx/prom.c:10:
arch/mips/bcm63xx/prom.c: In function 'prom_init':
./arch/mips/include/asm/string.h:162:11: error: '__builtin_memcpy' forming offset [2, 32] is out of the bounds [0, 1] of object 'bmips_smp_movevec' with type 'char' [-Werror=array-bounds]
   __ret = __builtin_memcpy((dst), (src), __len); \
           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
arch/mips/bcm63xx/prom.c:97:3: note: in expansion of macro 'memcpy'
   memcpy((void *)0xa0000200, &bmips_smp_movevec, 0x20);
   ^~~~~~
In file included from arch/mips/bcm63xx/prom.c:14:
./arch/mips/include/asm/bmips.h:80:13: note: 'bmips_smp_movevec' declared here
 extern char bmips_smp_movevec;

Fixes: 18a1eef92dcd ("MIPS: BMIPS: Introduce bmips.h")
Signed-off-by: Jonas Gorski 
Reviewed-by: Florian Fainelli 
Signed-off-by: Paul Burton 
Cc: linux-mips@vger.kernel.org
Cc: Ralf Baechle 
Cc: James Hogan 
Signed-off-by: Sasha Levin

MIPS: VDSO: Prevent use of smp_processor_id()

2019-09-21T05:14:05+00:00

commit 351fdddd366245c0fb4636f32edfb4198c8d6b8c upstream.

VDSO code should not be using smp_processor_id(), since it is executed
in user mode.
Introduce a VDSO-specific path which will cause a compile-time
or link-time error (depending upon support for __compiletime_error) if
the VDSO ever incorrectly attempts to use smp_processor_id().

[Matt Redfearn : Move before change to
smp_processor_id in series]

Signed-off-by: Paul Burton 
Signed-off-by: Matt Redfearn 
Patchwork: https://patchwork.linux-mips.org/patch/17932/
Cc: Ralf Baechle 
Cc: James Hogan 
Cc: linux-mips@linux-mips.org
Cc: Guenter Roeck 
Signed-off-by: Greg Kroah-Hartman

MIPS: ath79: fix ar933x uart parity mode

2019-08-04T07:33:13+00:00

[ Upstream commit db13a5ba2732755cf13320f3987b77cf2a71e790 ]

While trying to get the uart with parity working I found setting even
parity enabled odd parity insted. Fix the register settings to match
the datasheet of AR9331.

A similar patch was created by 8devices, but not sent upstream.
https://github.com/8devices/openwrt-8devices/commit/77c5586ade3bb72cda010afad3f209ed0c98ea7c

Signed-off-by: Stefan Hellermann 
Signed-off-by: Paul Burton 
Cc: linux-mips@vger.kernel.org
Signed-off-by: Sasha Levin

MIPS: Remove superfluous check for linux

2019-07-21T07:06:03+00:00

commit 1287533d3d95d5ad8b02773733044500b1be06bc upstream.

When building BPF code using "clang -target bpf -c", clang does not
define __linux__.

To build BPF IR decoders the include linux/lirc.h is needed which
includes linux/types.h. Currently this workaround is needed:

https://git.linuxtv.org/v4l-utils.git/commit/?id=dd3ff81f58c4e1e6f33765dc61ad33c48ae6bb07

This check might otherwise be useful to stop users from using a non-linux
compiler, but if you're doing that you are going to have a lot more
trouble anyway.

Signed-off-by: Sean Young 
Signed-off-by: Paul Burton 
Patchwork: https://patchwork.linux-mips.org/patch/21149/
Cc: Ralf Baechle 
Cc: James Hogan 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: Hauke Mehrtens 
Signed-off-by: Greg Kroah-Hartman