linux-stable.git/arch/mips/include/asm, branch linux-3.12.y

MIPS: Fix special case in 64 bit IP checksumming.

2017-03-13T20:40:15+00:00

commit 66fd848cadaa6be974a8c780fbeb328f0af4d3bd upstream.

For certain arguments such as saddr = 0xc0a8fd60, daddr = 0xc0a8fda1,
len = 80, proto = 17, sum = 0x7eae049d there will be a carry when
folding the intermediate 64 bit checksum to 32 bit but the code doesn't
add the carry back to the one's complement sum, thus an incorrect result
will be generated.

Reported-by: Mark Zhang 
Signed-off-by: Ralf Baechle 
Reviewed-by: James Hogan 
Signed-off-by: James Hogan 
Signed-off-by: Jiri Slaby

KVM: MIPS: Precalculate MMIO load resume PC

2016-11-09T21:29:50+00:00

commit e1e575f6b026734be3b1f075e780e91ab08ca541 upstream.

The advancing of the PC when completing an MMIO load is done before
re-entering the guest, i.e. before restoring the guest ASID. However if
the load is in a branch delay slot it may need to access guest code to
read the prior branch instruction. This isn't safe in TLB mapped code at
the moment, nor in the future when we'll access unmapped guest segments
using direct user accessors too, as it could read the branch from host
user memory instead.

Therefore calculate the resume PC in advance while we're still in the
right context and save it in the new vcpu->arch.io_pc (replacing the no
longer needed vcpu->arch.pending_load_cause), and restore it on MMIO
completion.

Fixes: e685c689f3a8 ("KVM/MIPS32: Privileged instruction/target branch emulation.")
Signed-off-by: James Hogan 
Cc: Paolo Bonzini 
Cc: "Radim Krčmář 
Cc: Ralf Baechle 
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Signed-off-by: Paolo Bonzini 
[james.hogan@imgtec.com: Backport to 3.10..3.16]
Signed-off-by: James Hogan 
Signed-off-by: Jiri Slaby

MIPS: ptrace: Fix regs_return_value for kernel context

2016-10-28T18:36:59+00:00

commit 74f1077b5b783e7bf4fa3007cefdc8dbd6c07518 upstream.

Currently regs_return_value always negates reg[2] if it determines
the syscall has failed, but when called in kernel context this check is
invalid and may result in returning a wrong value.

This fixes errors reported by CONFIG_KPROBES_SANITY_TEST

Fixes: d7e7528bcd45 ("Audit: push audit success and retcode into arch ptrace.h")
Signed-off-by: Marcin Nowakowski 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14381/
Signed-off-by: Ralf Baechle 
Signed-off-by: Jiri Slaby

mips: copy_from_user() must zero the destination on access_ok() failure

2016-09-29T09:14:34+00:00

commit e69d700535ac43a18032b3c399c69bf4639e89a2 upstream.

Signed-off-by: Al Viro 
Signed-off-by: Jiri Slaby

MIPS: KVM: Fix modular KVM under QEMU

2016-07-21T06:36:12+00:00

commit 797179bc4fe06c89e47a9f36f886f68640b423f8 upstream.

Copy __kvm_mips_vcpu_run() into unmapped memory, so that we can never
get a TLB refill exception in it when KVM is built as a module.

This was observed to happen with the host MIPS kernel running under
QEMU, due to a not entirely transparent optimisation in the QEMU TLB
handling where TLB entries replaced with TLBWR are copied to a separate
part of the TLB array. Code in those pages continue to be executable,
but those mappings persist only until the next ASID switch, even if they
are marked global.

An ASID switch happens in __kvm_mips_vcpu_run() at exception level after
switching to the guest exception base. Subsequent TLB mapped kernel
instructions just prior to switching to the guest trigger a TLB refill
exception, which enters the guest exception handlers without updating
EPC. This appears as a guest triggered TLB refill on a host kernel
mapped (host KSeg2) address, which is not handled correctly as user
(guest) mode accesses to kernel (host) segments always generate address
error exceptions.

Signed-off-by: James Hogan 
Cc: Paolo Bonzini 
Cc: Radim Krčmář 
Cc: Ralf Baechle 
Cc: kvm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Signed-off-by: Paolo Bonzini 
[james.hogan@imgtec.com: backported for stable 3.14]
Signed-off-by: James Hogan 
Signed-off-by: Jiri Slaby

MIPS: Fix 64k page support for 32 bit kernels.

2016-06-23T12:05:36+00:00

commit d7de413475f443957a0c1d256e405d19b3a2cb22 upstream.

TASK_SIZE was defined as 0x7fff8000UL which for 64k pages is not a
multiple of the page size.  Somewhere further down the math fails
such that executing an ELF binary fails.

Signed-off-by: Ralf Baechle 
Tested-by: Joshua Henderson 
Cc: James Hogan 
Signed-off-by: Jiri Slaby

arch: Introduce smp_load_acquire(), smp_store_release()

2015-08-25T14:56:59+00:00

commit 47933ad41a86a4a9b50bed7c9b9bd2ba242aac63 upstream.

A number of situations currently require the heavyweight smp_mb(),
even though there is no need to order prior stores against later
loads.  Many architectures have much cheaper ways to handle these
situations, but the Linux kernel currently has no portable way
to make use of them.

This commit therefore supplies smp_load_acquire() and
smp_store_release() to remedy this situation.  The new
smp_load_acquire() primitive orders the specified load against
any subsequent reads or writes, while the new smp_store_release()
primitive orders the specifed store against any prior reads or
writes.  These primitives allow array-based circular FIFOs to be
implemented without an smp_mb(), and also allow a theoretical
hole in rcu_assign_pointer() to be closed at no additional
expense on most architectures.

In addition, the RCU experience transitioning from explicit
smp_read_barrier_depends() and smp_wmb() to rcu_dereference()
and rcu_assign_pointer(), respectively resulted in substantial
improvements in readability.  It therefore seems likely that
replacing other explicit barriers with smp_load_acquire() and
smp_store_release() will provide similar benefits.  It appears
that roughly half of the explicit barriers in core kernel code
might be so replaced.

[Changelog by PaulMck]

Reviewed-by: "Paul E. McKenney" 
Signed-off-by: Peter Zijlstra 
Acked-by: Will Deacon 
Cc: Benjamin Herrenschmidt 
Cc: Frederic Weisbecker 
Cc: Mathieu Desnoyers 
Cc: Michael Ellerman 
Cc: Michael Neuling 
Cc: Russell King 
Cc: Geert Uytterhoeven 
Cc: Heiko Carstens 
Cc: Linus Torvalds 
Cc: Martin Schwidefsky 
Cc: Victor Kaplansky 
Cc: Tony Luck 
Cc: Oleg Nesterov 
Link: http://lkml.kernel.org/r/20131213150640.908486364@infradead.org
Signed-off-by: Ingo Molnar 
Signed-off-by: Jiri Slaby

MIPS: Make set_pte() SMP safe.

2015-08-19T06:36:46+00:00

commit 46011e6ea39235e4aca656673c500eac81a07a17 upstream.

On MIPS the GLOBAL bit of the PTE must have the same value in any
aligned pair of PTEs.  These pairs of PTEs are referred to as
"buddies".  In a SMP system is is possible for two CPUs to be calling
set_pte() on adjacent PTEs at the same time.  There is a race between
setting the PTE and a different CPU setting the GLOBAL bit in its
buddy PTE.

This race can be observed when multiple CPUs are executing
vmap()/vfree() at the same time.

Make setting the buddy PTE's GLOBAL bit an atomic operation to close
the race condition.

The case of CONFIG_64BIT_PHYS_ADDR && CONFIG_CPU_MIPS32 is *not*
handled.

Signed-off-by: David Daney 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/10835/
Signed-off-by: Ralf Baechle 
Signed-off-by: Jiri Slaby

MIPS: Fix KVM guest fixmap address

2015-07-30T12:10:42+00:00

commit 8e748c8d09a9314eedb5c6367d9acfaacddcdc88 upstream.

KVM guest kernels for trap & emulate run in user mode, with a modified
set of kernel memory segments. However the fixmap address is still in
the normal KSeg3 region at 0xfffe0000 regardless, causing problems when
cache alias handling makes use of them when handling copy on write.

Therefore define FIXADDR_TOP as 0x7ffe0000 in the guest kernel mapped
region when CONFIG_KVM_GUEST is defined.

Signed-off-by: James Hogan 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9887/
Signed-off-by: Ralf Baechle 
Signed-off-by: Jiri Slaby

nosave: consolidate __nosave_{begin,end} in

2015-05-04T09:49:04+00:00

commit 7f8998c7aef3ac9c5f3f2943e083dfa6302e90d0 upstream.

The different architectures used their own (and different) declarations:

    extern __visible const void __nosave_begin, __nosave_end;
    extern const void __nosave_begin, __nosave_end;
    extern long __nosave_begin, __nosave_end;

Consolidate them using the first variant in .

Signed-off-by: Geert Uytterhoeven 
Cc: Russell King 
Cc: Ralf Baechle 
Cc: Benjamin Herrenschmidt 
Cc: Martin Schwidefsky 
Cc: "David S. Miller" 
Cc: Guan Xuetao 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: "H. Peter Anvin" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Jiri Slaby 
[js -- port to 3.12: arm does not have hibernation yet]