linux.git/arch/mips/vdso, branch v4.9.209

MIPS: Disable Loongson MMI instructions for kernel build

2019-10-17T20:42:45+00:00

commit 2f2b4fd674cadd8c6b40eb629e140a14db4068fd upstream.

GCC 9.x automatically enables support for Loongson MMI instructions when
using some -march= flags, and then errors out when -msoft-float is
specified with:

  cc1: error: ‘-mloongson-mmi’ must be used with ‘-mhard-float’

The kernel shouldn't be using these MMI instructions anyway, just as it
doesn't use floating point instructions. Explicitly disable them in
order to fix the build with GCC 9.x.

Signed-off-by: Paul Burton 
Fixes: 3702bba5eb4f ("MIPS: Loongson: Add GCC 4.4 support for Loongson2E")
Fixes: 6f7a251a259e ("MIPS: Loongson: Add basic Loongson 2F support")
Fixes: 5188129b8c9f ("MIPS: Loongson-3: Improve -march option and move it to Platform")
Cc: Huacai Chen 
Cc: Jiaxun Yang 
Cc: stable@vger.kernel.org # v2.6.32+
Cc: linux-mips@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

MIPS: VDSO: Use same -m%-float cflag as the kernel proper

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

commit 0648e50e548d881d025b9419a1a168753c8e2bf7 upstream.

The MIPS VDSO build currently doesn't provide the -msoft-float flag to
the compiler as the kernel proper does. This results in an attempt to
use the compiler's default floating point configuration, which can be
problematic in cases where this is incompatible with the target CPU's
-march= flag. For example decstation_defconfig fails to build using
toolchains in which gcc was configured --with-fp-32=xx with the
following error:

    LDS     arch/mips/vdso/vdso.lds
  cc1: error: '-march=r3000' requires '-mfp32'
  make[2]: *** [scripts/Makefile.build:379: arch/mips/vdso/vdso.lds] Error 1

The kernel proper avoids this error because we build with the
-msoft-float compiler flag, rather than using the compiler's default.
Pass this flag through to the VDSO build so that it too becomes agnostic
to the toolchain's floating point configuration.

Note that this is filtered out from KBUILD_CFLAGS rather than simply
always using -msoft-float such that if we switch the kernel to use
-mno-float in the future the VDSO will automatically inherit the change.

The VDSO doesn't actually include any floating point code, and its
.MIPS.abiflags section is already manually generated to specify that
it's compatible with any floating point ABI. As such this change should
have no effect on the resulting VDSO, apart from fixing the build
failure for affected toolchains.

Signed-off-by: Paul Burton 
Reported-by: Kevin Hilman 
Reported-by: Guenter Roeck 
Tested-by: Kevin Hilman 
References: https://lore.kernel.org/linux-mips/1477843551-21813-1-git-send-email-linux@roeck-us.net/
References: https://kernelci.org/build/id/5c4e4ae059b5142a249ad004/logs/
Fixes: ebb5e78cc634 ("MIPS: Initial implementation of a VDSO")
Cc: Maciej W. Rozycki 
Cc: linux-mips@vger.kernel.org
Cc: stable@vger.kernel.org # v4.4+
Cc: Guenter Roeck 
Signed-off-by: Greg Kroah-Hartman

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: VDSO: Include $(ccflags-vdso) in o32,n32 .lds builds

2019-02-15T07:07:38+00:00

commit 67fc5dc8a541e8f458d7f08bf88ff55933bf9f9d upstream.

When generating vdso-o32.lds & vdso-n32.lds for use with programs
running as compat ABIs under 64b kernels, we previously haven't included
the compiler flags that are supposedly common to all ABIs - ie. those in
the ccflags-vdso variable.

This is problematic in cases where we need to provide the -m%-float flag
in order to ensure that we don't attempt to use a floating point ABI
that's incompatible with the target CPU & ABI. For example a toolchain
using current gcc trunk configured --with-fp-32=xx fails to build a
64r6el_defconfig kernel with the following error:

  cc1: error: '-march=mips1' requires '-mfp32'
  make[2]: *** [arch/mips/vdso/Makefile:135: arch/mips/vdso/vdso-o32.lds] Error 1

Include $(ccflags-vdso) for the compat VDSO .lds builds, just as it is
included for the native VDSO .lds & when compiling objects for the
compat VDSOs. This ensures we consistently provide the -msoft-float flag
amongst others, avoiding the problem by ensuring we're agnostic to the
toolchain defaults.

Signed-off-by: Paul Burton 
Fixes: ebb5e78cc634 ("MIPS: Initial implementation of a VDSO")
Cc: linux-mips@vger.kernel.org
Cc: Kevin Hilman 
Cc: Guenter Roeck 
Cc: Maciej W . Rozycki 
Cc: stable@vger.kernel.org # v4.4+
Signed-off-by: Greg Kroah-Hartman

MIPS: VDSO: Drop duplicated -I/-E aflags

2016-10-11T13:07:30+00:00

The aflags-vdso is based on ccflags-vdso, which already contains the -I*
and -EL/-EB flags from KBUILD_CFLAGS, but those flags are needlessly
added again to aflags-vdso.

Drop the duplication.

Signed-off-by: James Hogan 
Reported-by: Maciej W. Rozycki 
Reviewed-by: Maciej W. Rozycki 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14369/
Signed-off-by: Ralf Baechle

MIPS: Fix -mabi=64 build of vdso.lds

2016-10-11T13:03:47+00:00

The native ABI vDSO linker script vdso.lds is built by preprocessing
vdso.lds.S, with the native -mabi flag passed in to get the correct ABI
definitions. Unfortunately however certain toolchains choke on -mabi=64
without a corresponding compatible -march flag, for example:

cc1: error: ‘-march=mips32r2’ is not compatible with the selected ABI
scripts/Makefile.build:338: recipe for target 'arch/mips/vdso/vdso.lds' failed

Fix this by including ccflags-vdso in the KBUILD_CPPFLAGS for vdso.lds,
which includes the appropriate -march flag.

Fixes: ebb5e78cc634 ("MIPS: Initial implementation of a VDSO")
Signed-off-by: James Hogan 
Reviewed-by: Maciej W. Rozycki 
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org # 4.4.x-
Patchwork: https://patchwork.linux-mips.org/patch/14368/
Signed-off-by: Ralf Baechle

MIPS: Build microMIPS VDSO for microMIPS kernels

2016-05-28T10:35:12+00:00

MicroMIPS kernels may be expected to run on microMIPS only cores which
don't support the normal MIPS instruction set, so be sure to pass the
-mmicromips flag through to the VDSO cflags.

Fixes: ebb5e78cc634 ("MIPS: Initial implementation of a VDSO")
Signed-off-by: James Hogan 
Cc: Paul Burton 
Cc: linux-mips@linux-mips.org
Cc:  # 4.4.x-
Patchwork: https://patchwork.linux-mips.org/patch/13349/
Signed-off-by: Ralf Baechle

MIPS: VDSO: Build with `-fno-strict-aliasing'

2016-05-28T10:35:12+00:00

Avoid an aliasing issue causing a build error in VDSO:

In file included from include/linux/srcu.h:34:0,
                 from include/linux/notifier.h:15,
                 from ./arch/mips/include/asm/uprobes.h:9,
                 from include/linux/uprobes.h:61,
                 from include/linux/mm_types.h:13,
                 from ./arch/mips/include/asm/vdso.h:14,
                 from arch/mips/vdso/vdso.h:27,
                 from arch/mips/vdso/gettimeofday.c:11:
include/linux/workqueue.h: In function 'work_static':
include/linux/workqueue.h:186:2: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing]
  return *work_data_bits(work) & WORK_STRUCT_STATIC;
  ^
cc1: all warnings being treated as errors
make[2]: *** [arch/mips/vdso/gettimeofday.o] Error 1

with a CONFIG_DEBUG_OBJECTS_WORK configuration and GCC 5.2.0.  Include
`-fno-strict-aliasing' along with compiler options used, as required for
kernel code, fixing a problem present since the introduction of VDSO
with commit ebb5e78cc634 ("MIPS: Initial implementation of a VDSO").

Thanks to Tejun for diagnosing this properly!

Signed-off-by: Maciej W. Rozycki 
Reviewed-by: James Hogan 
Fixes: ebb5e78cc634 ("MIPS: Initial implementation of a VDSO")
Cc: Tejun Heo 
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org # v4.3+
Patchwork: https://patchwork.linux-mips.org/patch/13357/
Signed-off-by: Ralf Baechle

MIPS: Fix genvdso error on rebuild

2016-05-13T20:47:39+00:00

The genvdso program modifies the debug and stripped versions of the
VDSOs in place, and errors if the modification has already taken place.
Unfortunately this means that a rebuild which tries to rerun genvdso to
generate vdso*-image.c without also rebuilding vdso.so.dbg (for example
if genvdso.c is modified) hits a build error like this:

arch/mips/vdso/genvdso 'arch/mips/vdso/vdso.so.dbg' already contains a '.MIPS.abiflags' section

This is fixed by reorganising the rules such that unmodified .so files
have a .raw suffix, and these are copied in the same rule that runs
genvdso on the copies.

I.e. previously we had:

 cmd_vdsold:
  link objects -> vdso.so.dbg

 cmd_genvdso:
  strip vdso.so.dbg -> vdso.so
  run genvdso -> vdso-image.c
   and modify vdso.so.dbg and vdso.so in place

Now we have:

 cmd_vdsold:
  link objects -> vdso.so.dbg.raw

 a new cmd_objcopy based strip rule (inspired by ARM):
  strip vdso.so.dbg.raw -> vdso.so.raw

 cmd_genvdso:
  copy vdso.so.dbg.raw -> vdso.so.dbg
  copy vdso.so.raw -> vdso.so
  run genvdso -> vdso-image.c
   and modify vdso.so.dbg and vdso.so in place

Signed-off-by: James Hogan 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13250/
Signed-off-by: Ralf Baechle

Fix ld-version.sh to handle large 3rd version part

2016-01-04T09:22:52+00:00

The ld-version.sh script doesn't handle versions with large (>= 10) 3rd
version components, because the 2nd component is only multiplied by 10
times that of the 3rd component.

For example the following version string:
GNU ld (Codescape GNU Tools 2015.06-05 for MIPS MTI Linux) 2.24.90

gives a bogus version number:
 20000000
+ 2400000
+  900000 = 23300000

Breakage, confusion and mole-whacking ensues.

Increase the multipliers of the first two version components by a factor
of 10 to give space for a 3rd components of up to 99, and update the
sole user of ld-ifversion (MIPS VDSO) accordingly.

Signed-off-by: James Hogan 
Acked-by: Guenter Roeck 
Reviewed-by: Andi Kleen 
Cc: Andi Kleen 
Cc: Michal Marek 
Cc: Guenter Roeck 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11931/
Signed-off-by: Ralf Baechle

linux.git/arch/mips/vdso, branch v4.9.209

MIPS: Disable Loongson MMI instructions for kernel build

MIPS: VDSO: Use same -m%-float cflag as the kernel proper

MIPS: VDSO: Prevent use of smp_processor_id()

MIPS: VDSO: Include $(ccflags-vdso) in o32,n32 .lds builds

MIPS: VDSO: Drop duplicated -I*/-E* aflags

MIPS: Fix -mabi=64 build of vdso.lds

MIPS: Build microMIPS VDSO for microMIPS kernels

MIPS: VDSO: Build with `-fno-strict-aliasing'

MIPS: Fix genvdso error on rebuild

Fix ld-version.sh to handle large 3rd version part

MIPS: VDSO: Drop duplicated -I/-E aflags