linux-stable.git/arch/mips, branch v4.4.210

MIPS: Avoid VDSO ABI breakage due to global register variable

2020-01-12T10:22:41+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

2019-12-21T09:34:45+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: OCTEON: octeon-platform: fix typing

2019-12-21T09:34:32+00:00

[ Upstream commit 2cf1c8933dd93088cfb5f8f58b3bb9bbdf1781b9 ]

Use correct type for fdt_property nameoff field.

Signed-off-by: Aaro Koskinen 
Signed-off-by: Paul Burton 
Patchwork: https://patchwork.linux-mips.org/patch/21204/
Cc: Ralf Baechle 
Cc: James Hogan 
Cc: linux-mips@linux-mips.org
Signed-off-by: Sasha Levin

MIPS: SiByte: Enable ZONE_DMA32 for LittleSur

2019-12-21T09:34:29+00:00

[ Upstream commit 756d6d836dbfb04a5a486bc2ec89397aa4533737 ]

The LittleSur board is marked for high memory support and therefore
clearly must provide a way to have enough memory installed for some to
be present outside the low 4GiB physical address range.  With the memory
map of the BCM1250 SOC it has been built around it means over 1GiB of
actual DRAM, as only the first 1GiB is mapped in the low 4GiB physical
address range[1].

Complement commit cce335ae47e2 ("[MIPS] 64-bit Sibyte kernels need
DMA32.") then and also enable ZONE_DMA32 for LittleSur.

References:

[1] "BCM1250/BCM1125/BCM1125H User Manual", Revision 1250_1125-UM100-R,
    Broadcom Corporation, 21 Oct 2002, Section 3: "System Overview",
    "Memory Map", pp. 34-38

Signed-off-by: Maciej W. Rozycki 
Signed-off-by: Paul Burton 
Reviewed-by: Christoph Hellwig 
Patchwork: https://patchwork.linux-mips.org/patch/21107/
Fixes: cce335ae47e2 ("[MIPS] 64-bit Sibyte kernels need DMA32.")
Cc: Ralf Baechle 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Sasha Levin

MIPS: kexec: Relax memory restriction

2019-11-25T14:54:08+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: txx9: fix iounmap related issue

2019-11-25T14:53:49+00:00

[ Upstream commit c6e1241a82e6e74d1ae5cc34581dab2ffd6022d0 ]

if device_register return error, iounmap should be called, also iounmap
need to call before put_device.

Signed-off-by: Ding Xiang 
Reviewed-by: Atsushi Nemoto 
Signed-off-by: Paul Burton 
Patchwork: https://patchwork.linux-mips.org/patch/20476/
Cc: ralf@linux-mips.org
Cc: jhogan@kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Sasha Levin

MIPS: BCM47XX: Enable USB power on Netgear WNDR3400v3

2019-11-25T14:53:46+00:00

[ Upstream commit feef7918667b84f9d5653c501542dd8d84ae32af ]

Setting GPIO 21 high seems to be required to enable power to USB ports
on the WNDR3400v3. As there is already similar code for WNR3500L,
make the existing USB power GPIO code generic and use that.

Signed-off-by: Tuomas Tynkkynen 
Acked-by: Hauke Mehrtens 
Signed-off-by: Paul Burton 
Patchwork: https://patchwork.linux-mips.org/patch/20259/
Cc: Rafał Miłecki 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Sasha Levin

MIPS: BCM63XX: fix switch core reset on BCM6368

2019-11-16T09:27:48+00:00

commit 8a38dacf87180738d42b058334c951eba15d2d47 upstream.

The Ethernet Switch core mask was set to 0, causing the switch core to
be not reset on BCM6368 on boot. Provide the proper mask so the switch
core gets reset to a known good state.

Fixes: 799faa626c71 ("MIPS: BCM63XX: add core reset helper")
Signed-off-by: Jonas Gorski 
Signed-off-by: Paul Burton 
Cc: linux-mips@vger.kernel.org
Cc: Ralf Baechle 
Cc: James Hogan 
Cc: Florian Fainelli 
Signed-off-by: Amit Pundir 
Signed-off-by: Greg Kroah-Hartman

MIPS: bmips: mark exception vectors as char arrays

2019-11-10T10:21:09+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: fw: sni: Fix out of bounds init of o32 stack

2019-11-06T11:09:15+00:00

[ Upstream commit efcb529694c3b707dc0471b312944337ba16e4dd ]

Use ARRAY_SIZE to caluculate the top of the o32 stack.

Signed-off-by: Thomas Bogendoerfer 
Signed-off-by: Paul Burton 
Cc: Ralf Baechle 
Cc: James Hogan 
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Sasha Levin