linux-toradex.git/arch/mips/include/asm, branch v4.4.73

MIPS: Only change $28 to thread_info if coming from user mode

2017-04-18T05:14:36+00:00

commit 510d86362a27577f5ee23f46cfb354ad49731e61 upstream.

The SAVE_SOME macro is used to save the execution context on all
exceptions.
If an exception occurs while executing user code, the stack is switched
to the kernel's stack for the current task, and register $28 is switched
to point to the current_thread_info, which is at the bottom of the stack
region.
If the exception occurs while executing kernel code, the stack is left,
and this change ensures that register $28 is not updated. This is the
correct behaviour when the kernel can be executing on the separate irq
stack, because the thread_info will not be at the base of it.

With this change, register $28 is only switched to it's kernel
conventional usage of the currrent thread info pointer at the point at
which execution enters kernel space. Doing it on every exception was
redundant, but OK without an IRQ stack, but will be erroneous once that
is introduced.

Signed-off-by: Matt Redfearn 
Acked-by: Jason A. Donenfeld 
Cc: Thomas Gleixner 
Cc: James Hogan 
Cc: Paul Burton 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14742/
Signed-off-by: Ralf Baechle 
Signed-off-by: Amit Pundir 
Signed-off-by: Greg Kroah-Hartman

MIPS: Introduce irq_stack

2017-04-18T05:14:35+00:00

commit fe8bd18ffea5327344d4ec2bf11f47951212abd0 upstream.

Allocate a per-cpu irq stack for use within interrupt handlers.

Also add a utility function on_irq_stack to determine if a given stack
pointer is within the irq stack for that cpu.

Signed-off-by: Matt Redfearn 
Acked-by: Jason A. Donenfeld 
Cc: Thomas Gleixner 
Cc: Paolo Bonzini 
Cc: Chris Metcalf 
Cc: Petr Mladek 
Cc: James Hogan 
Cc: Paul Burton 
Cc: Aaron Tomlin 
Cc: Andrew Morton 
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14740/
Signed-off-by: Ralf Baechle 
Signed-off-by: Amit Pundir 
Signed-off-by: Greg Kroah-Hartman

MIPS: End spinlocks with .insn

2017-04-12T10:38:35+00:00

commit 4b5347a24a0f2d3272032c120664b484478455de upstream.

When building for microMIPS we need to ensure that the assembler always
knows that there is code at the target of a branch or jump. Recent
toolchains will fail to link a microMIPS kernel when this isn't the case
due to what it thinks is a branch to non-microMIPS code.

mips-mti-linux-gnu-ld kernel/built-in.o: .spinlock.text+0x2fc: Unsupported branch between ISA modes.
mips-mti-linux-gnu-ld final link failed: Bad value

This is due to inline assembly labels in spinlock.h not being followed
by an instruction mnemonic, either due to a .subsection pseudo-op or the
end of the inline asm block.

Fix this with a .insn direction after such labels.

Signed-off-by: Paul Burton 
Signed-off-by: James Hogan 
Reviewed-by: Maciej W. Rozycki 
Cc: Ralf Baechle 
Cc: Peter Zijlstra 
Cc: Ingo Molnar 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/15325/
Signed-off-by: James Hogan 
Signed-off-by: Greg Kroah-Hartman

MIPS: Fix special case in 64 bit IP checksumming.

2017-03-12T05:37:23+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: Greg Kroah-Hartman

KVM: MIPS: Precalculate MMIO load resume PC

2016-11-18T09:48:36+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 3.18..4.4]
Signed-off-by: James Hogan 
Signed-off-by: Greg Kroah-Hartman

MIPS: ptrace: Fix regs_return_value for kernel context

2016-10-28T07:01:30+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: Greg Kroah-Hartman

MIPS: uprobes: remove incorrect set_orig_insn

2016-10-07T13:23:42+00:00

commit ddabfa5c2e33f1b495f3e0176de7057850915c0b upstream.

Generic kernel code implements a weak version of set_orig_insn that
moves cached 'insn' from arch_uprobe to the original code location when
the trap is removed.
MIPS variant used arch_uprobe->orig_inst which was never initialised
properly, so this code only inserted a nop instead of the original
instruction. With that change orig_inst can also be safely removed.

Signed-off-by: Marcin Nowakowski 
Fixes: 40e084a506eb ('MIPS: Add uprobes support.')
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14299/
Signed-off-by: Ralf Baechle 
Signed-off-by: Greg Kroah-Hartman

MIPS: paravirt: Fix undefined reference to smp_bootstrap

2016-09-30T08:18:39+00:00

commit 951c39cd3bc0aedf67fbd8fb4b9380287e6205d1 upstream.

If the paravirt machine is compiles without CONFIG_SMP, the following
linker error occurs

arch/mips/kernel/head.o: In function `kernel_entry':
(.ref.text+0x10): undefined reference to `smp_bootstrap'

due to the kernel entry macro always including SMP startup code.
Wrap this code in CONFIG_SMP to fix the error.

Signed-off-by: Matt Redfearn 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14212/
Signed-off-by: Ralf Baechle 
Signed-off-by: Greg Kroah-Hartman

MIPS: Add a missing ".set pop" in an early commit

2016-09-30T08:18:39+00:00

commit 3cbc6fc9c99f1709203711f125bc3b79487aba06 upstream.

Commit 842dfc11ea9a21 ("MIPS: Fix build with binutils 2.24.51+") missing
a ".set pop" in macro fpu_restore_16even, so add it.

Signed-off-by: Huacai Chen 
Acked-by: Manuel Lauss 
Cc: Steven J . Hill 
Cc: Fuxin Zhang 
Cc: Zhangjin Wu 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14210/
Signed-off-by: Ralf Baechle 
Signed-off-by: Greg Kroah-Hartman

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

2016-09-24T08:07:45+00:00

commit e69d700535ac43a18032b3c399c69bf4639e89a2 upstream.

Signed-off-by: Al Viro 
Signed-off-by: Greg Kroah-Hartman