linux-stable.git/arch/mips/include/asm, branch v3.18.48

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

2016-10-06T02:40:20+00:00

[ Upstream commit e69d700535ac43a18032b3c399c69bf4639e89a2 ]

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro 
Signed-off-by: Sasha Levin

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

2016-10-06T02:40:20+00:00

[ Upstream commit 3cbc6fc9c99f1709203711f125bc3b79487aba06 ]

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
Cc: stable@vger.kernel.org # 3.18+
Patchwork: https://patchwork.linux-mips.org/patch/14210/
Signed-off-by: Ralf Baechle 
Signed-off-by: Sasha Levin

MIPS: paravirt: Fix undefined reference to smp_bootstrap

2016-10-06T02:40:20+00:00

[ Upstream commit 951c39cd3bc0aedf67fbd8fb4b9380287e6205d1 ]

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
Cc: stable@vger.kernel.org # 3.16+
Patchwork: https://patchwork.linux-mips.org/patch/14212/
Signed-off-by: Ralf Baechle 
Signed-off-by: Sasha Levin

MIPS: Fix page table corruption on THP permission changes.

2016-07-20T15:35:52+00:00

[ Upstream commit 88d02a2ba6c52350f9a73ff1b01a5be839c3ca17 ]

When the core THP code is modifying the permissions of a huge page it
calls pmd_modify(), which unfortunately was clearing the _PAGE_HUGE bit
of the page table entry.  The result can be kernel messages like:

mm/memory.c:397: bad pmd 000000040080004d.
mm/memory.c:397: bad pmd 00000003ff00004d.
mm/memory.c:397: bad pmd 000000040100004d.

or:

------------[ cut here ]------------
WARNING: at mm/mmap.c:3200 exit_mmap+0x150/0x158()
Modules linked in: ipv6 at24 octeon3_ethernet octeon_srio_nexus m25p80
CPU: 12 PID: 1295 Comm: pmderr Not tainted 3.10.87-rt80-Cavium-Octeon #4
Stack : 0000000040808000 0000000014009ce1 0000000000400004 ffffffff81076ba0
          0000000000000000 0000000000000000 ffffffff85110000 0000000000000119
          0000000000000004 0000000000000000 0000000000000119 43617669756d2d4f
          0000000000000000 ffffffff850fda40 ffffffff85110000 0000000000000000
          0000000000000000 0000000000000009 ffffffff809207a0 0000000000000c80
          ffffffff80f1bf20 0000000000000001 000000ffeca36828 0000000000000001
          0000000000000000 0000000000000001 000000ffeca7e700 ffffffff80886924
          80000003fd7a0000 80000003fd7a39b0 80000003fdea8000 ffffffff80885780
          80000003fdea8000 ffffffff80f12218 000000000000000c 000000000000050f
          0000000000000000 ffffffff80865c4c 0000000000000000 0000000000000000
          ...
Call Trace:
[] show_stack+0x6c/0xf8
[] warn_slowpath_common+0x78/0xa8
[] exit_mmap+0x150/0x158
[] mmput+0x5c/0x110
[] do_exit+0x230/0xa68
[] do_group_exit+0x54/0x1d0
[] __wake_up_parent+0x0/0x18

---[ end trace c7b38293191c57dc ]---
BUG: Bad rss-counter state mm:80000003fa168000 idx:1 val:1536

Fix by not clearing _PAGE_HUGE bit.

Signed-off-by: David Daney 
Tested-by: Aaro Koskinen 
Cc: stable@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13687/
Signed-off-by: Ralf Baechle 
Signed-off-by: Sasha Levin

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

2016-07-12T12:48:27+00:00

[ Upstream commit d7de413475f443957a0c1d256e405d19b3a2cb22 ]

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 
Signed-off-by: Sasha Levin

MIPS: KVM: Fix modular KVM under QEMU

2016-07-11T15:16:28+00:00

[ Upstream commit 797179bc4fe06c89e47a9f36f886f68640b423f8 ]

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
Cc:  # 3.10.x-
Signed-off-by: Paolo Bonzini 
Signed-off-by: Sasha Levin

MIPS: MSA: Fix a link error on `_init_msa_upper' with older GCC

2016-06-06T23:11:06+00:00

[ Upstream commit e49d38488515057dba8f0c2ba4cfde5be4a7281f ]

Fix a build regression from commit c9017757c532 ("MIPS: init upper 64b
of vector registers when MSA is first used"):

arch/mips/built-in.o: In function `enable_restore_fp_context':
traps.c:(.text+0xbb90): undefined reference to `_init_msa_upper'
traps.c:(.text+0xbb90): relocation truncated to fit: R_MIPS_26 against `_init_msa_upper'
traps.c:(.text+0xbef0): undefined reference to `_init_msa_upper'
traps.c:(.text+0xbef0): relocation truncated to fit: R_MIPS_26 against `_init_msa_upper'

to !CONFIG_CPU_HAS_MSA configurations with older GCC versions, which are
unable to figure out that calls to `_init_msa_upper' are indeed dead.
Of the many ways to tackle this failure choose the approach we have
already taken in `thread_msa_context_live'.

[ralf@linux-mips.org: Drop patch segment to junk file.]

Signed-off-by: Maciej W. Rozycki 
Cc: stable@vger.kernel.org # v3.16+
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13271/
Signed-off-by: Ralf Baechle 
Signed-off-by: Sasha Levin

MIPS: KVM: Fix timer IRQ race when writing CP0_Compare

2016-06-06T23:11:02+00:00

[ Upstream commit b45bacd2d048f405c7760e5cc9b60dd67708734f ]

Writing CP0_Compare clears the timer interrupt pending bit
(CP0_Cause.TI), but this wasn't being done atomically. If a timer
interrupt raced with the write of the guest CP0_Compare, the timer
interrupt could end up being pending even though the new CP0_Compare is
nowhere near CP0_Count.

We were already updating the hrtimer expiry with
kvm_mips_update_hrtimer(), which used both kvm_mips_freeze_hrtimer() and
kvm_mips_resume_hrtimer(). Close the race window by expanding out
kvm_mips_update_hrtimer(), and clearing CP0_Cause.TI and setting
CP0_Compare between the freeze and resume. Since the pending timer
interrupt should not be cleared when CP0_Compare is written via the KVM
user API, an ack argument is added to distinguish the source of the
write.

Fixes: e30492bbe95a ("MIPS: KVM: Rewrite count/compare timer emulation")
Signed-off-by: James Hogan 
Cc: Paolo Bonzini 
Cc: "Radim KrÄmÃ¡Å™" 
Cc: Ralf Baechle 
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Cc:  # 3.16.x-
Signed-off-by: Paolo Bonzini 
Signed-off-by: Sasha Levin

MIPS: Fix buffer overflow in syscall_get_arguments()

2016-03-02T20:18:54+00:00

[ Upstream commit f4dce1ffd2e30fa31756876ef502ce6d2324be35 ]

Since commit 4c21b8fd8f14 ("MIPS: seccomp: Handle indirect system calls
(o32)"), syscall_get_arguments() attempts to handle o32 indirect syscall
arguments by incrementing both the start argument number and the number
of arguments to fetch. However only the start argument number needs to
be incremented. The number of arguments does not change, they're just
shifted up by one, and in fact the output array is provided by the
caller and is likely only n entries long, so reading more arguments
overflows the output buffer.

In the case of seccomp, this results in it fetching 7 arguments starting
at the 2nd one, which overflows the unsigned long args[6] in
populate_seccomp_data(). This clobbers the $s0 register from
syscall_trace_enter() which __seccomp_phase1_filter() saved onto the
stack, into which syscall_trace_enter() had placed its syscall number
argument. This caused Chromium to crash.

Credit goes to Milko for tracking it down as far as $s0 being clobbered.

Fixes: 4c21b8fd8f14 ("MIPS: seccomp: Handle indirect system calls (o32)")
Reported-by: Milko Leporis 
Signed-off-by: James Hogan 
Cc: linux-mips@linux-mips.org
Cc:  # 3.15-
Patchwork: https://patchwork.linux-mips.org/patch/12213/
Signed-off-by: Ralf Baechle 
Signed-off-by: Sasha Levin

MIPS: Make set_pte() SMP safe.

2015-08-19T17:15:59+00:00

[ Upstream commit 46011e6ea39235e4aca656673c500eac81a07a17 ]

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: 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/10835/
Signed-off-by: Ralf Baechle 
Signed-off-by: Sasha Levin