linux-stable.git/arch/powerpc/kernel/vdso.c, branch linux-4.7.y

vdso: make arch_setup_additional_pages wait for mmap_sem for write killable

2016-05-24T00:04:14+00:00

most architectures are relying on mmap_sem for write in their
arch_setup_additional_pages.  If the waiting task gets killed by the oom
killer it would block oom_reaper from asynchronous address space reclaim
and reduce the chances of timely OOM resolving.  Wait for the lock in
the killable mode and return with EINTR if the task got killed while
waiting.

Signed-off-by: Michal Hocko 
Acked-by: Andy Lutomirski 	[x86 vdso]
Acked-by: Vlastimil Babka 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

powerpc: Standardise on NR_syscalls rather than __NR_syscalls.

2015-11-26T11:11:17+00:00

Most architectures use NR_syscalls as the #define for the number of syscalls.

We use __NR_syscalls, and then define NR_syscalls as __NR_syscalls.

__NR_syscalls is not used outside arch code, whereas NR_syscalls is. So as
NR_syscalls must be defined and __NR_syscalls does not, replace __NR_syscalls
with NR_syscalls.

Signed-off-by: Rashmica Gupta 
Signed-off-by: Michael Ellerman

powerpc/vdso: Disable building the 32-bit VDSO on little endian

2015-05-11T10:01:02+00:00

The only little endian configuration we support is ppc64le. As such if
we're building little endian we don't need a 32-bit VDSO, because there
is no 32-bit userspace.

This patch is a fairly ugly mess of #ifdefs, but is the minimal logic
required to disable the 32-bit VDSO. We can hopefully clean up the
result in future with some further refactoring.

Signed-off-by: Michael Ellerman

powerpc/vdso: Combine start/size variables

2015-05-11T10:00:32+00:00

In vdso_fixup_features() we have start64/start32 and size64/size32, but
they have the same types, ie. void * and unsigned long.

They're only used to save the return value from find_sectionXX() for the
subsequent call to do_feature_fixups(), so there's no overlap in their
usage either.

So we can just consolidate them into start/size and avoid the
duplication.

Signed-off-by: Michael Ellerman

powerpc/vdso: Remove unused debug code

2015-05-11T10:00:32+00:00

It's in the git history if we ever need it back.

Signed-off-by: Michael Ellerman

powerpc: Remove superfluous bootmem includes

2014-11-09T22:59:26+00:00

Lots of places included bootmem.h even when not using bootmem.

Signed-off-by: Anton Blanchard 
Tested-by: Emil Medve 
Signed-off-by: Michael Ellerman

arm64,ia64,ppc,s390,sh,tile,um,x86,mm: remove default gate area

2014-08-08T22:57:27+00:00

The core mm code will provide a default gate area based on
FIXADDR_USER_START and FIXADDR_USER_END if
!defined(__HAVE_ARCH_GATE_AREA) && defined(AT_SYSINFO_EHDR).

This default is only useful for ia64.  arm64, ppc, s390, sh, tile, 64-bit
UML, and x86_32 have their own code just to disable it.  arm, 32-bit UML,
and x86_64 have gate areas, but they have their own implementations.

This gets rid of the default and moves the code into ia64.

This should save some code on architectures without a gate area: it's now
possible to inline the gate_area functions in the default case.

Signed-off-by: Andy Lutomirski 
Acked-by: Nathan Lynch 
Acked-by: H. Peter Anvin 
Acked-by: Benjamin Herrenschmidt  [in principle]
Acked-by: Richard Weinberger  [for um]
Acked-by: Will Deacon  [for arm64]
Cc: Catalin Marinas 
Cc: Will Deacon 
Cc: Tony Luck 
Cc: Fenghua Yu 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
Cc: Chris Metcalf 
Cc: Jeff Dike 
Cc: Richard Weinberger 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: "H. Peter Anvin" 
Cc: Nathan Lynch 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

powerpc/booke64: Use SPRG7 for VDSO

2014-03-20T00:57:14+00:00

Previously SPRG3 was marked for use by both VDSO and critical
interrupts (though critical interrupts were not fully implemented).

In commit 8b64a9dfb091f1eca8b7e58da82f1e7d1d5fe0ad ("powerpc/booke64:
Use SPRG0/3 scratch for bolted TLB miss & crit int"), Mihai Caraman
made an attempt to resolve this conflict by restoring the VDSO value
early in the critical interrupt, but this has some issues:

 - It's incompatible with EXCEPTION_COMMON which restores r13 from the
   by-then-overwritten scratch (this cost me some debugging time).
 - It forces critical exceptions to be a special case handled
   differently from even machine check and debug level exceptions.
 - It didn't occur to me that it was possible to make this work at all
   (by doing a final "ld r13, PACA_EXCRIT+EX_R13(r13)") until after
   I made (most of) this patch. :-)

It might be worth investigating using a load rather than SPRG on return
from all exceptions (except TLB misses where the scratch never leaves
the SPRG) -- it could save a few cycles.  Until then, let's stick with
SPRG for all exceptions.

Since we cannot use SPRG4-7 for scratch without corrupting the state of
a KVM guest, move VDSO to SPRG7 on book3e.  Since neither SPRG4-7 nor
critical interrupts exist on book3s, SPRG3 is still used for VDSO
there.

Signed-off-by: Scott Wood 
Cc: Mihai Caraman 
Cc: Anton Blanchard 
Cc: Paul Mackerras 
Cc: kvm-ppc@vger.kernel.org

powerpc: Move local setup.h declarations to arch includes

2013-10-30T05:00:31+00:00

Move the few declarations from arch/powerpc/kernel/setup.h
into arch/powerpc/include/asm/setup.h.  This resolves a
sparse warning for arch/powerpc/mm/numa.c which defines
do_init_bootmem() but can't include the setup.h header
in the prior path.

Resolves:
arch/powerpc/mm/numa.c:998:13:
        warning: symbol 'do_init_bootmem' was not declared.
                 Should it be static?

Signed-off-by: Robert C Jennings 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Delete __cpuinit usage from all users

2013-07-01T01:10:36+00:00

The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications.  For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.

After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out.  Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.

This removes all the powerpc uses of the __cpuinit macros.  There
are no __CPUINIT users in assembly files in powerpc.

[1] https://lkml.org/lkml/2013/5/20/589

Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: Josh Boyer 
Cc: Matt Porter 
Cc: Kumar Gala 
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Paul Gortmaker 
Signed-off-by: Benjamin Herrenschmidt