linux.git/arch, branch v3.18.91

powerpc/perf: Dereference BHRB entries safely

2018-01-02T19:04:57+00:00

commit f41d84dddc66b164ac16acf3f584c276146f1c48 upstream.

It's theoretically possible that branch instructions recorded in
BHRB (Branch History Rolling Buffer) entries have already been
unmapped before they are processed by the kernel. Hence, trying to
dereference such memory location will result in a crash. eg:

    Unable to handle kernel paging request for data at address 0xd000000019c41764
    Faulting instruction address: 0xc000000000084a14
    NIP [c000000000084a14] branch_target+0x4/0x70
    LR [c0000000000eb828] record_and_restart+0x568/0x5c0
    Call Trace:
    [c0000000000eb3b4] record_and_restart+0xf4/0x5c0 (unreliable)
    [c0000000000ec378] perf_event_interrupt+0x298/0x460
    [c000000000027964] performance_monitor_exception+0x54/0x70
    [c000000000009ba4] performance_monitor_common+0x114/0x120

Fix it by deferefencing the addresses safely.

Fixes: 691231846ceb ("powerpc/perf: Fix setting of "to" addresses for BHRB")
Suggested-by: Naveen N. Rao 
Signed-off-by: Ravi Bangoria 
Reviewed-by: Naveen N. Rao 
[mpe: Use probe_kernel_read() which is clearer, tweak change log]
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

KVM: X86: Fix load RFLAGS w/o the fixed bit

2018-01-02T19:04:57+00:00

commit d73235d17ba63b53dc0e1051dbc10a1f1be91b71 upstream.

 *** Guest State ***
 CR0: actual=0x0000000000000030, shadow=0x0000000060000010, gh_mask=fffffffffffffff7
 CR4: actual=0x0000000000002050, shadow=0x0000000000000000, gh_mask=ffffffffffffe871
 CR3 = 0x00000000fffbc000
 RSP = 0x0000000000000000  RIP = 0x0000000000000000
 RFLAGS=0x00000000         DR7 = 0x0000000000000400
        ^^^^^^^^^^

The failed vmentry is triggered by the following testcase when ept=Y:

    #include 
    #include 
    #include 
    #include 
    #include 
    #include 
    #include 

    long r[5];
    int main()
    {
    	r[2] = open("/dev/kvm", O_RDONLY);
    	r[3] = ioctl(r[2], KVM_CREATE_VM, 0);
    	r[4] = ioctl(r[3], KVM_CREATE_VCPU, 7);
    	struct kvm_regs regs = {
    		.rflags = 0,
    	};
    	ioctl(r[4], KVM_SET_REGS, ®s);
    	ioctl(r[4], KVM_RUN, 0);
    }

X86 RFLAGS bit 1 is fixed set, userspace can simply clearing bit 1
of RFLAGS with KVM_SET_REGS ioctl which results in vmentry fails.
This patch fixes it by oring X86_EFLAGS_FIXED during ioctl.

Suggested-by: Jim Mattson 
Reviewed-by: David Hildenbrand 
Reviewed-by: Quan Xu 
Cc: Paolo Bonzini 
Cc: Radim Krčmář 
Cc: Jim Mattson 
Signed-off-by: Wanpeng Li 
Signed-off-by: Paolo Bonzini 
Signed-off-by: Greg Kroah-Hartman

ARM: dma-mapping: disallow dma_get_sgtable() for non-kernel managed memory

2017-12-25T13:20:08+00:00

[ Upstream commit 916a008b4b8ecc02fbd035cfb133773dba1ff3d7 ]

dma_get_sgtable() tries to create a scatterlist table containing valid
struct page pointers for the coherent memory allocation passed in to it.

However, memory can be declared via dma_declare_coherent_memory(), or
via other reservation schemes which means that coherent memory is not
guaranteed to be backed by struct pages.  In such cases, the resulting
scatterlist table contains pointers to invalid pages, which causes
kernel oops later.

This patch adds detection of such memory, and refuses to create a
scatterlist table for such memory.

Reported-by: Shuah Khan 
Signed-off-by: Russell King 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

ARM: dts: am335x-evmsk: adjust mmc2 param to allow suspend

2017-12-25T13:20:08+00:00

[ Upstream commit 9bcf53f34a2c1cebc45cc12e273dcd5f51fbc099 ]

mmc2 used for wl12xx was missing the keep-power-in suspend
parameter. As a result the board couldn't reach suspend state.

Signed-off-by: Eyal Reizer 
Signed-off-by: Tony Lindgren 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

ARM: dts: ti: fix PCI bus dtc warnings

2017-12-25T13:20:07+00:00

[ Upstream commit 7d79f6098d82f8c09914d7799bc96891ad9c3baf ]

dtc recently added PCI bus checks. Fix these warnings.

Signed-off-by: Rob Herring 
Cc: "Benoît Cousson" 
Cc: Tony Lindgren 
Cc: linux-omap@vger.kernel.org
Signed-off-by: Tony Lindgren 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

KVM: x86: correct async page present tracepoint

2017-12-25T13:20:07+00:00

[ Upstream commit 24dccf83a121b8a4ad5c2ad383a8184ef6c266ee ]

After async pf setup successfully, there is a broadcast wakeup w/ special
token 0xffffffff which tells vCPU that it should wake up all processes
waiting for APFs though there is no real process waiting at the moment.

The async page present tracepoint print prematurely and fails to catch the
special token setup. This patch fixes it by moving the async page present
tracepoint after the special token setup.

Before patch:

qemu-system-x86-8499  [006] ...1  5973.473292: kvm_async_pf_ready: token 0x0 gva 0x0

After patch:

qemu-system-x86-8499  [006] ...1  5973.473292: kvm_async_pf_ready: token 0xffffffff gva 0x0

Cc: Paolo Bonzini 
Cc: Radim Krčmář 
Signed-off-by: Wanpeng Li 
Signed-off-by: Paolo Bonzini 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

arm64: Initialise high_memory global variable earlier

2017-12-25T13:20:05+00:00

commit f24e5834a2c3f6c5f814a417f858226f0a010ade upstream.

The high_memory global variable is used by
cma_declare_contiguous(.) before it is defined.

We don't notice this as we compute __pa(high_memory - 1), and it looks
like we're processing a VA from the direct linear map.

This problem becomes apparent when we flip the kernel virtual address
space and the linear map is moved to the bottom of the kernel VA space.

This patch moves the initialisation of high_memory before it used.

Fixes: f7426b983a6a ("mm: cma: adjust address limit to avoid hitting low/high memory boundary")
Signed-off-by: Steve Capper 
Signed-off-by: Will Deacon 
Signed-off-by: Greg Kroah-Hartman

pinctrl: adi2: Fix Kconfig build problem

2017-12-20T09:01:33+00:00

[ Upstream commit 1c363531dd814dc4fe10865722bf6b0f72ce4673 ]

The build robot is complaining on Blackfin:

drivers/pinctrl/pinctrl-adi2.c: In function 'port_setup':
>> drivers/pinctrl/pinctrl-adi2.c:221:21: error: dereferencing
   pointer to incomplete type 'struct gpio_port_t'
      writew(readw(®s->port_fer) & ~BIT(offset),
                        ^~
drivers/pinctrl/pinctrl-adi2.c: In function 'adi_gpio_ack_irq':
>> drivers/pinctrl/pinctrl-adi2.c:266:18: error: dereferencing
pointer to incomplete type 'struct bfin_pint_regs'
      if (readl(®s->invert_set) & pintbit)
                     ^~
It seems the driver need to include  and 
to compile.

The Blackfin architecture was re-defining the Kconfig
PINCTRL symbol which is not OK, so replaced this with
PINCTRL_BLACKFIN_ADI2 which selects PINCTRL and PINCTRL_ADI2
just like most arches do.

Further, the old GPIO driver symbol GPIO_ADI was possible to
select at the same time as selecting PINCTRL. This was not
working because the arch-local  header contains
an explicit #ifndef PINCTRL clause making compilation break
if you combine them. The same is true for DEBUG_MMRS.

Make sure the ADI2 pinctrl driver is not selected at the same
time as the old GPIO implementation. (This should be converted
to use gpiolib or pincontrol and move to drivers/...) Also make
sure the old GPIO_ADI driver or DEBUG_MMRS is not selected at
the same time as the new PINCTRL implementation, and only make
PINCTRL_ADI2 selectable for the Blackfin families that actually
have it.

This way it is still possible to add e.g. I2C-based pin
control expanders on the Blackfin.

Cc: Steven Miao 
Cc: Huanhuan Feng 
Signed-off-by: Linus Walleij 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

powerpc/ipic: Fix status get and status clear

2017-12-20T09:01:32+00:00

[ Upstream commit 6b148a7ce72a7f87c81cbcde48af014abc0516a9 ]

IPIC Status is provided by register IPIC_SERSR and not by IPIC_SERMR
which is the mask register.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

powerpc/opal: Fix EBUSY bug in acquiring tokens

2017-12-20T09:01:32+00:00

[ Upstream commit 71e24d7731a2903b1ae2bba2b2971c654d9c2aa6 ]

The current code checks the completion map to look for the first token
that is complete. In some cases, a completion can come in but the
token can still be on lease to the caller processing the completion.
If this completed but unreleased token is the first token found in the
bitmap by another tasks trying to acquire a token, then the
__test_and_set_bit call will fail since the token will still be on
lease. The acquisition will then fail with an EBUSY.

This patch reorganizes the acquisition code to look at the
opal_async_token_map for an unleased token. If the token has no lease
it must have no outstanding completions so we should never see an
EBUSY, unless we have leased out too many tokens. Since
opal_async_get_token_inrerruptible is protected by a semaphore, we
will practically never see EBUSY anymore.

Fixes: 8d7248232208 ("powerpc/powernv: Infrastructure to support OPAL async completion")
Signed-off-by: William A. Kennington III 
Signed-off-by: Michael Ellerman 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman