linux-stable.git/arch/powerpc, branch v3.16.71

powerpc/32: Clear on-stack exception marker upon exception return

2019-07-09T21:04:10+00:00

commit 9580b71b5a7863c24a9bd18bcd2ad759b86b1eff upstream.

Clear the on-stack STACK_FRAME_REGS_MARKER on exception exit in order
to avoid confusing stacktrace like the one below.

  Call Trace:
  [c0e9dca0] [c01c42a0] print_address_description+0x64/0x2bc (unreliable)
  [c0e9dcd0] [c01c4684] kasan_report+0xfc/0x180
  [c0e9dd10] [c0895130] memchr+0x24/0x74
  [c0e9dd30] [c00a9e38] msg_print_text+0x124/0x574
  [c0e9dde0] [c00ab710] console_unlock+0x114/0x4f8
  [c0e9de40] [c00adc60] vprintk_emit+0x188/0x1c4
  --- interrupt: c0e9df00 at 0x400f330
      LR = init_stack+0x1f00/0x2000
  [c0e9de80] [c00ae3c4] printk+0xa8/0xcc (unreliable)
  [c0e9df20] [c0c27e44] early_irq_init+0x38/0x108
  [c0e9df50] [c0c15434] start_kernel+0x310/0x488
  [c0e9dff0] [00003484] 0x3484

With this patch the trace becomes:

  Call Trace:
  [c0e9dca0] [c01c42c0] print_address_description+0x64/0x2bc (unreliable)
  [c0e9dcd0] [c01c46a4] kasan_report+0xfc/0x180
  [c0e9dd10] [c0895150] memchr+0x24/0x74
  [c0e9dd30] [c00a9e58] msg_print_text+0x124/0x574
  [c0e9dde0] [c00ab730] console_unlock+0x114/0x4f8
  [c0e9de40] [c00adc80] vprintk_emit+0x188/0x1c4
  [c0e9de80] [c00ae3e4] printk+0xa8/0xcc
  [c0e9df20] [c0c27e44] early_irq_init+0x38/0x108
  [c0e9df50] [c0c15434] start_kernel+0x310/0x488
  [c0e9dff0] [00003484] 0x3484

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Signed-off-by: Ben Hutchings

powerpc/powernv: Make opal log only readable by root

2019-07-09T21:04:08+00:00

commit 7b62f9bd2246b7d3d086e571397c14ba52645ef1 upstream.

Currently the opal log is globally readable. It is kernel policy to
limit the visibility of physical addresses / kernel pointers to root.
Given this and the fact the opal log may contain this information it
would be better to limit the readability to root.

Fixes: bfc36894a48b ("powerpc/powernv: Add OPAL message log interface")
Signed-off-by: Jordan Niethe 
Reviewed-by: Stewart Smith 
Reviewed-by: Andrew Donnellan 
Signed-off-by: Michael Ellerman 
Signed-off-by: Ben Hutchings

powerpc/mm/hash: Handle mmap_min_addr correctly in get_unmapped_area topdown search

2019-07-09T21:04:07+00:00

commit 3b4d07d2674f6b4a9281031f99d1f7efd325b16d upstream.

When doing top-down search the low_limit is not PAGE_SIZE but rather
max(PAGE_SIZE, mmap_min_addr). This handle cases in which mmap_min_addr >
PAGE_SIZE.

Fixes: fba2369e6ceb ("mm: use vm_unmapped_area() on powerpc architecture")
Reviewed-by: Laurent Dufour 
Signed-off-by: Aneesh Kumar K.V 
Signed-off-by: Michael Ellerman 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

powerpc/wii: properly disable use of BATs when requested.

2019-07-09T21:04:05+00:00

commit 6d183ca8baec983dc4208ca45ece3c36763df912 upstream.

'nobats' kernel parameter or some options like CONFIG_DEBUG_PAGEALLOC
deny the use of BATS for mapping memory.

This patch makes sure that the specific wii RAM mapping function
takes it into account as well.

Fixes: de32400dd26e ("wii: use both mem1 and mem2 as ram")
Reviewed-by: Jonathan Neuschafer 
Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Signed-off-by: Ben Hutchings

powerpc/83xx: Also save/restore SPRG4-7 during suspend

2019-07-09T21:04:05+00:00

commit 36da5ff0bea2dc67298150ead8d8471575c54c7d upstream.

The 83xx has 8 SPRG registers and uses at least SPRG4
for DTLB handling LRU.

Fixes: 2319f1239592 ("powerpc/mm: e300c2/c3/c4 TLB errata workaround")
Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Signed-off-by: Ben Hutchings

powerpc/irq: drop arch_early_irq_init()

2019-07-09T21:03:46+00:00

commit 607ea5090b3fb61fea1d0bc5278e6c1d40ab5bd6 upstream.

arch_early_irq_init() does nothing different than the weak
arch_early_irq_init() in kernel/softirq.c

Fixes: 089fb442f301 ("powerpc: Use ARCH_IRQ_INIT_FLAGS")
Signed-off-by: Christophe Leroy 
Acked-by: Thomas Gleixner 
Signed-off-by: Michael Ellerman 
Signed-off-by: Ben Hutchings

locking/static_keys: Add a new static_key interface

2019-05-22T22:15:05+00:00

commit 11276d5306b8e5b438a36bbff855fe792d7eaa61 upstream.

There are various problems and short-comings with the current
static_key interface:

 - static_key_{true,false}() read like a branch depending on the key
   value, instead of the actual likely/unlikely branch depending on
   init value.

 - static_key_{true,false}() are, as stated above, tied to the
   static_key init values STATIC_KEY_INIT_{TRUE,FALSE}.

 - we're limited to the 2 (out of 4) possible options that compile to
   a default NOP because that's what our arch_static_branch() assembly
   emits.

So provide a new static_key interface:

  DEFINE_STATIC_KEY_TRUE(name);
  DEFINE_STATIC_KEY_FALSE(name);

Which define a key of different types with an initial true/false
value.

Then allow:

   static_branch_likely()
   static_branch_unlikely()

to take a key of either type and emit the right instruction for the
case.

This means adding a second arch_static_branch_jump() assembly helper
which emits a JMP per default.

In order to determine the right instruction for the right state,
encode the branch type in the LSB of jump_entry::key.

This is the final step in removing the naming confusion that has led to
a stream of avoidable bugs such as:

  a833581e372a ("x86, perf: Fix static_key bug in load_mm_cr4()")

... but it also allows new static key combinations that will give us
performance enhancements in the subsequent patches.

Tested-by: Rabin Vincent  # arm
Signed-off-by: Peter Zijlstra (Intel) 
Acked-by: Michael Ellerman  # ppc
Acked-by: Heiko Carstens  # s390
Cc: Andrew Morton 
Cc: Linus Torvalds 
Cc: Paul E. McKenney 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar 
[bwh: Backported to 3.16:
 - For s390, use the 31-bit-compatible macros in arch_static_branch_jump()
 - 
Signed-off-by: Ben Hutchings

jump_label: Rename JUMP_LABEL_{EN,DIS}ABLE to JUMP_LABEL_{JMP,NOP}

2019-05-22T22:15:03+00:00

commit 76b235c6bcb16062d663e2ee96db0b69f2e6bc14 upstream.

Since we've already stepped away from ENABLE is a JMP and DISABLE is a
NOP with the branch_default bits, and are going to make it even worse,
rename it to make it all clearer.

This way we don't mix multiple levels of logic attributes, but have a
plain 'physical' name for what the current instruction patching status
of a jump label is.

This is a first step in removing the naming confusion that has led to
a stream of avoidable bugs such as:

  a833581e372a ("x86, perf: Fix static_key bug in load_mm_cr4()")

Signed-off-by: Peter Zijlstra (Intel) 
Cc: Andrew Morton 
Cc: Linus Torvalds 
Cc: Paul E. McKenney 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
[ Beefed up the changelog. ]
Signed-off-by: Ingo Molnar 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

powerpc/signal: Properly handle return value from uprobe_deny_signal()

2019-05-02T20:41:45+00:00

commit 46725b17f1c6c815a41429259b3f070c01e71bc1 upstream.

When a uprobe is installed on an instruction that we currently do not
emulate, we copy the instruction into a xol buffer and single step
that instruction. If that instruction generates a fault, we abort the
single stepping before invoking the signal handler. Once the signal
handler is done, the uprobe trap is hit again since the instruction is
retried and the process repeats.

We use uprobe_deny_signal() to detect if the xol instruction triggered
a signal. If so, we clear TIF_SIGPENDING and set TIF_UPROBE so that the
signal is not handled until after the single stepping is aborted. In
this case, uprobe_deny_signal() returns true and get_signal() ends up
returning 0. However, in do_signal(), we are not looking at the return
value, but depending on ksig.sig for further action, all with an
uninitialized ksig that is not touched in this scenario. Fix the same
by initializing ksig.sig to 0.

Fixes: 129b69df9c90 ("powerpc: Use get_signal() signal_setup_done()")
Reported-by: Anton Blanchard 
Signed-off-by: Naveen N. Rao 
Signed-off-by: Michael Ellerman 
Signed-off-by: Ben Hutchings

powerpc: Use sigsp()

2019-05-02T20:41:45+00:00

commit 059ade650ae57cfd371af690fdba887af04aded8 upstream.

Use sigsp() instead of the open coded variant.

Signed-off-by: Richard Weinberger 
[bwh: Backported to 3.16 as dependency of commit 35634ffa1751
 "signal: Always notice exiting tasks"]
Signed-off-by: Ben Hutchings