linux.git/arch/mips/include/asm/vdso, branch v5.6

mips: vdso: Remove unused VDSO_HAS_32BIT_FALLBACK

2020-01-14T11:20:46+00:00

VDSO_HAS_32BIT_FALLBACK has been removed from the core since
the architectures that support the generic vDSO library have
been converted to support the 32 bit fallbacks.

Remove unused VDSO_HAS_32BIT_FALLBACK from mips vdso.

Signed-off-by: Vincenzo Frascino 
Signed-off-by: Thomas Gleixner 
Acked-by: Paul Burton 
Link: https://lore.kernel.org/r/20190830135902.20861-8-vincenzo.frascino@arm.com

Merge tag 'mips_fixes_5.5_1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux

2020-01-04T22:16:57+00:00

Pull MIPS fixes from Paul Burton:
 "A collection of MIPS fixes:

   - Fill the struct cacheinfo shared_cpu_map field with sensible
     values, notably avoiding issues with perf which was unhappy in the
     absence of these values.

   - A boot fix for Loongson 2E & 2F machines which was fallout from
     some refactoring performed this cycle.

   - A Kconfig dependency fix for the Loongson CPU HWMon driver.

   - A couple of VDSO fixes, ensuring gettimeofday() behaves
     appropriately for kernel configurations that don't include support
     for a clocksource the VDSO can use & fixing the calling convention
     for the n32 & n64 VDSOs which would previously clobber the $gp/$28
     register.

   - A build fix for vmlinuz compressed images which were
     inappropriately building with -fsanitize-coverage despite not being
     part of the kernel proper, then failing to link due to the missing
     __sanitizer_cov_trace_pc() function.

   - A couple of eBPF JIT fixes, including disabling it for MIPS32 due
     to a large number of issues with the code generated there &
     reflecting ISA dependencies in Kconfig to enforce that systems
     which don't support the JIT must include the interpreter"

* tag 'mips_fixes_5.5_1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
  MIPS: Avoid VDSO ABI breakage due to global register variable
  MIPS: BPF: eBPF JIT: check for MIPS ISA compliance in Kconfig
  MIPS: BPF: Disable MIPS32 eBPF JIT
  MIPS: Prevent link failure with kcov instrumentation
  MIPS: Kconfig: Use correct form for 'depends on'
  mips: Fix gettimeofday() in the vdso library
  MIPS: Fix boot on Fuloong2 systems
  mips: cacheinfo: report shared CPU map

mips: Fix gettimeofday() in the vdso library

2019-12-02T18:50:37+00:00

The libc provides a discovery mechanism for vDSO library and its
symbols. When a symbol is not exposed by the vDSOs the libc falls back
on the system calls.

With the introduction of the unified vDSO library on mips this behavior
is not honored anymore by the kernel in the case of gettimeofday().

The issue has been noticed and reported due to a dhclient failure on the
CI20 board:

root@letux:~# dhclient
../../../../lib/isc/unix/time.c:200: Operation not permitted
root@letux:~#

Restore the original behavior fixing gettimeofday() in the vDSO library.

Reported-by: H. Nikolaus Schaller 
Tested-by: H. Nikolaus Schaller  # CI20 with JZ4780
Signed-off-by: Vincenzo Frascino 
Signed-off-by: Paul Burton 
Cc: mips-creator-ci20-dev@googlegroups.com
Cc: letux-kernel@openphoenux.org
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

timekeeping/vsyscall: Update VDSO data unconditionally

2019-11-04T22:02:53+00:00

The update of the VDSO data is depending on __arch_use_vsyscall() returning
True. This is a leftover from the attempt to map the features of various
architectures 1:1 into generic code.

The usage of __arch_use_vsyscall() in the actual vsyscall implementations
got dropped and replaced by the requirement for the architecture code to
return U64_MAX if the global clocksource is not usable in the VDSO.

But the __arch_use_vsyscall() check in the update code stayed which causes
the VDSO data to be stale or invalid when an architecture actually
implements that function and returns False when the current clocksource is
not usable in the VDSO.

As a consequence the VDSO implementations of clock_getres(), time(),
clock_gettime(CLOCK_.*_COARSE) operate on invalid data and return bogus
information.

Remove the __arch_use_vsyscall() check from the VDSO update function and
update the VDSO data unconditionally.

[ tglx: Massaged changelog and removed the now useless implementations in
  	asm-generic/ARM64/MIPS ]

Fixes: 44f57d788e7deecb50 ("timekeeping: Provide a generic update_vsyscall() implementation")
Signed-off-by: Huacai Chen 
Signed-off-by: Thomas Gleixner 
Cc: Andy Lutomirski 
Cc: Vincenzo Frascino 
Cc: Arnd Bergmann 
Cc: Paul Burton 
Cc: linux-mips@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1571887709-11447-1-git-send-email-chenhc@lemote.com

mips: vdso: Fix __arch_get_hw_counter()

2019-10-18T21:29:16+00:00

On some MIPS variants (e.g. MIPS r1), vDSO clock_mode is set to
VDSO_CLOCK_NONE.

When VDSO_CLOCK_NONE is set the expected kernel behavior is to fallback
on syscalls. To do that the generic vDSO library expects UULONG_MAX as
return value of __arch_get_hw_counter().

Fix __arch_get_hw_counter() on MIPS defining a __VDSO_USE_SYSCALL case
that addressed the described scenario.

Reported-by: Maxime Bizon 
Signed-off-by: Vincenzo Frascino 
Tested-by: Maxime Bizon 
Signed-off-by: Paul Burton 
Cc: linux-mips@vger.kernel.org

mips: compat: vdso: Use legacy syscalls as fallback

2019-09-03T14:35:23+00:00

The generic VDSO implementation uses the Y2038 safe clock_gettime64() and
clock_getres_time64() syscalls as fallback for 32bit VDSO. This breaks
seccomp setups because these syscalls might be not (yet) allowed.

Implement the 32bit variants which use the legacy syscalls and select the
variant in the core library.

The 64bit time variants are not removed because they are required for the
time64 based vdso accessors.

Cc: Paul Burton 
Fixes: 00b26474c2f1 ("lib/vdso: Provide generic VDSO implementation")
Signed-off-by: Vincenzo Frascino 
Signed-off-by: Paul Burton 
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@vger.kernel.org
Cc: linux-kselftest@vger.kernel.org
Cc: catalin.marinas@arm.com
Cc: will@kernel.org
Cc: tglx@linutronix.de
Cc: salyzyn@android.com
Cc: 0x7f454c46@gmail.com
Cc: luto@kernel.org

mips: fix vdso32 build, again

2019-08-06T21:32:15+00:00

The generic vdso support adds the same #if hack in two places,
asm/vdso/vdso.h and config-n32-o32-env.c, but only the second
is actually used. The result lacks the BUILD_VDSO32_64 macro,
and that triggers a build error:

./include/linux/page-flags-layout.h:95:2: error: #error "Not enough bits in page flags"

Move the macro into the other place, and remove the duplicated
bits.

Reported-by: Guenter Roeck 
Fixes: ee38d94a0ad8 ("page flags: prioritize kasan bits over last-cpuid")
Fixes: 24640f233b46 ("mips: Add support for generic vDSO")
Signed-off-by: Arnd Bergmann 
Signed-off-by: Paul Burton 
Cc: Andrew Morton 
Cc: Andrey Konovalov 
Cc: Andrey Ryabinin 
Cc: Dmitry Vyukov 
Cc: Will Deacon 
Cc: Christoph Lameter 
Cc: Mark Rutland 
Cc: Ralf Baechle 
Cc: Vincenzo Frascino 
Cc: James Hogan 
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

mips: Add clock_getres entry point

2019-07-26T04:45:35+00:00

The generic vDSO library provides an implementation of clock_getres()
that can be leveraged by each architecture.

Add clock_getres() entry point on mips.

Cc: Ralf Baechle 
Cc: Paul Burton 
Signed-off-by: Vincenzo Frascino 
Signed-off-by: Paul Burton

mips: Add support for generic vDSO

2019-07-26T04:45:05+00:00

The mips vDSO library requires some adaptations to take advantage of the
newly introduced generic vDSO library.

Introduce the following changes:
 - Modification of vdso.c to be compliant with the common vdso datapage
 - Use of lib/vdso for gettimeofday

Cc: Ralf Baechle 
Cc: Paul Burton 
Signed-off-by: Vincenzo Frascino 
[paul.burton@mips.com: Prepend $(src) to config-n32-o32-env.c path.]
Signed-off-by: Paul Burton