linux.git/arch/mips/vdso, branch v4.13

MIPS: VDSO: Fix clobber lists in fallback code paths

2017-08-07T11:53:25+00:00

Extend clobber lists to include all GP registers.

Fixes: 0b523a85e134 ("MIPS: VDSO: Add implementation of gettimeofday() fallback")

Signed-off-by: Miodrag Dinic 
Signed-off-by: Goran Ferenc 
Signed-off-by: Aleksandar Markovic 
Reviewed-by: James Hogan 
Cc: Bo Hu 
Cc: Douglas Leung 
Cc: James Hogan 
Cc: Jin Qian 
Cc: Paul Burton 
Cc: Petar Jovanovic 
Cc: Raghu Gandham 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16879/
Signed-off-by: Ralf Baechle

MIPS: VDSO: Fix a mismatch between comment and preprocessor constant

2017-06-29T00:42:30+00:00

Sync the comment with its preprocessor constant counterpart.

Signed-off-by: Aleksandar Markovic 
Cc: James Hogan 
Cc: Miodrag Dinic 
Cc: Paul Burton 
Cc: Petar Jovanovic 
Cc: Raghu Gandham 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16641/
Signed-off-by: Ralf Baechle

MIPS: VDSO: Add implementation of gettimeofday() fallback

2017-06-29T00:42:30+00:00

This patch adds gettimeofday_fallback() function that wraps assembly
invocation of gettimeofday() syscall using __NR_gettimeofday.

This function is used if pure VDSO implementation gettimeofday()
does not succeed for any reason. Its imeplementation is enclosed in
"#ifdef CONFIG_MIPS_CLOCK_VSYSCALL" to be in sync with the similar
arrangement for __vdso_gettimeofday().

If syscall invocation via __NR_gettimeofday fails, register a3 will
be set. So, after the syscall, register a3 is tested and the return
valuem is negated if it's set.

Signed-off-by: Goran Ferenc 
Signed-off-by: Miodrag Dinic 
Signed-off-by: Aleksandar Markovic 
Cc: Douglas Leung 
Cc: James Hogan 
Cc: Paul Burton 
Cc: Petar Jovanovic 
Cc: Raghu Gandham 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16640/
Signed-off-by: Ralf Baechle

MIPS: VDSO: Add implementation of clock_gettime() fallback

2017-06-29T00:42:29+00:00

This patch adds clock_gettime_fallback() function that wraps assembly
invocation of clock_gettime() syscall using __NR_clock_gettime.

This function is used if pure VDSO implementation of clock_gettime()
does not succeed for any reason. For example, it is called if the
clkid parameter of clock_gettime() is not one of the clkids listed
in the switch-case block of the function __vdso_clock_gettime()
(one such case for clkid is CLOCK_BOOTIME).

If syscall invocation via __NR_clock_gettime fails, register a3 will
be set. So, after the syscall, register a3 is tested and the return
value is negated if it's set.

Signed-off-by: Goran Ferenc 
Signed-off-by: Miodrag Dinic 
Signed-off-by: Aleksandar Markovic 
Cc: Douglas Leung 
Cc: James Hogan 
Cc: Paul Burton 
Cc: Petar Jovanovic 
Cc: Raghu Gandham 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16639/
Signed-off-by: Ralf Baechle

MIPS: VDSO: Fix conversions in do_monotonic()/do_monotonic_coarse()

2017-06-29T00:42:29+00:00

Fix incorrect calculation in do_monotonic() and do_monotonic_coarse()
function that in turn caused incorrect values returned by the vdso
version of system call clock_gettime() on mips64 if its system clock
ID parameter was CLOCK_MONOTONIC or CLOCK_MONOTONIC_COARSE.

Consider these variables and their types on mips32 and mips64:

tk->wall_to_monotonic.tv_sec  s64, s64   (kernel/vdso.c)
vdso_data.wall_to_mono_sec    u32, u32   (kernel/vdso.c)
to_mono_sec                   u32, u32   (vdso/gettimeofday.c)
ts->tv_sec                    s32, s64   (vdso/gettimeofday.c)

For mips64 case, u32 vdso_data.wall_to_mono_sec variable is updated
from the 64-bit signed variable tk->wall_to_monotonic.tv_sec
(kernel/vdso.c:76) which is a negative number holding the time passed
from 1970-01-01 to the time boot started. This 64-bit signed value is
currently around 47+ years, in seconds. For instance, let this value
be:

-1489757461

or

11111111111111111111111111111111 10100111001101000001101011101011

By updating 32-bit vdso_data.wall_to_mono_sec variable, we lose upper
32 bits (signed 1's).

to_mono_sec variable is a parameter of do_monotonic() and
do_monotonic_coarse() functions which holds vdso_data.wall_to_mono_sec
value. Its value needs to be added (or subtracted considering it holds
negative value from the tk->wall_to_monotonic.tv_sec) to the current
time passed from 1970-01-01 (ts->tv_sec), which is again something like
47+ years, but increased by the time passed from the boot to the
current time. ts->tv_sec is 32-bit long in case of 32-bit architecture
and 64-bit long in case of 64-bit architecture. Consider the update of
ts->tv_sec (vdso/gettimeofday.c:55 & 167):

ts->tv_sec += to_mono_sec;

mips32 case: This update will be performed correctly, since both
ts->tv_sec and to_mono_sec are 32-bit long and the sign in to_mono_sec
is preserved. Implicit conversion from u32 to s32 will be done
correctly.

mips64 case: This update will be wrong, since the implicit conversion
will not be done correctly. The reason is that the conversion will be
from u32 to s64. This is because to_mono_sec is 32-bit long for both
mips32 and mips64 cases and s64..33 bits of converted to_mono_sec
variable will be zeros.

So, in order to make MIPS64 implementation work properly for
MONOTONIC and MONOTONIC_COARSE clock ids on mips64, the size of
wall_to_mono_sec variable in mips_vdso_data union and respective
parameters in do_monotonic() and do_monotonic_coarse() functions
should be changed from u32 to u64. Because of consistency, this
size change from u32 and u64 is also done for wall_to_mono_nsec
variable and corresponding function parameters.

As far as similar situations for other architectures are concerned,
let's take a look at arm. Arm has two distinct vdso_data structures
for 32-bit & 64-bit cases, and arm's wall_to_mono_sec and
wall_to_mono_nsec are u32 for 32-bit and u64 for 64-bit cases.
On the other hand, MIPS has only one structure (mips_vdso_data),
hence the need for changing the size of above mentioned parameters.

Signed-off-by: Goran Ferenc 
Signed-off-by: Miodrag Dinic 
Signed-off-by: Aleksandar Markovic 
Cc: Douglas Leung 
Cc: James Hogan 
Cc: Paul Burton 
Cc: Petar Jovanovic 
Cc: Raghu Gandham 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16638/
Signed-off-by: Ralf Baechle

MIPS: VDSO: Explicitly use -fno-asynchronous-unwind-tables

2017-02-17T11:32:12+00:00

Not every toolchain has -fno-asynchronous-unwind-tables per default on
MIPS. This patch specifies the necessary option explicitly for VDSO
library build.

This prevents the following build failure:
GENVDSO arch/mips/vdso/vdso-image.c
arch/mips/vdso/genvdso: 'arch/mips/vdso/vdso.so.dbg' contains relocation sections
.../arch/mips/vdso/Makefile:84: recipe for target 'arch/mips/vdso/vdso-image.c' failed

Signed-off-by: Robert Schiele 
Signed-off-by: Alexander Sverdlin 
Cc: Ralf Baechle 
Cc: "Maciej W. Rozycki" 
Cc: Alexander Sverdlin 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/15127/
Signed-off-by: James Hogan

MIPS: Fix modversions

2017-01-24T17:30:35+00:00

kernelci.org reports tons of build warnings for linux-next:

35	WARNING: "memcpy" [fs/fat/msdos.ko] has no CRC!
35	WARNING: "__copy_user" [fs/fat/fat.ko] has no CRC!
32	WARNING: EXPORT symbol "memset" [vmlinux] version generation failed, symbol will not be versioned.
32	WARNING: EXPORT symbol "copy_page" [vmlinux] version generation failed, symbol will not be versioned.
32	WARNING: EXPORT symbol "clear_page" [vmlinux] version generation failed, symbol will not be versioned.
32	WARNING: EXPORT symbol "__strncpy_from_user_nocheck_asm" [vmlinux] version generation failed, symbol will not be versioned.

The problem here is mainly the missing asm/asm-prototypes.h header file
that is supposed to include the prototypes for each symbol that is exported
from an assembler file.

A second problem is that the asm/uaccess.h header contains some but not
all the necessary declarations for the user access helpers.

Finally, the vdso build is broken once we add asm/asm-prototypes.h, so
we have to fix this at the same time by changing the vdso header. My
approach here is to just not look for exported symbols in the VDSO
assembler files, as the symbols cannot be exported anyway.

Fixes: 576a2f0c5c6d ("MIPS: Export memcpy & memset functions alongside their definitions")
Signed-off-by: Arnd Bergmann 
Cc: Al Viro 
Cc: James Hogan 
Cc: Maciej W. Rozycki 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/15038/
Patchwork: https://patchwork.linux-mips.org/patch/15069/
Signed-off-by: Ralf Baechle

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