linux-stable.git/arch/m68k, branch linux-3.12.y

m68k: Fix ndelay() macro

2017-01-26T16:22:20+00:00

commit 7e251bb21ae08ca2e4fb28cc0981fac2685a8efa upstream.

The current ndelay() macro definition has an extra semi-colon at the
end of the line thus leading to a compilation error when ndelay is used
in a conditional block without curly braces like this one:

	if (cond)
		ndelay(t);
	else
		...

which, after the preprocessor pass gives:

	if (cond)
		m68k_ndelay(t);;
	else
		...

thus leading to the following gcc error:

	error: 'else' without a previous 'if'

Remove this extra semi-colon.

Signed-off-by: Boris Brezillon 
Fixes: c8ee038bd1488 ("m68k: Implement ndelay() based on the existing udelay() logic")
Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Jiri Slaby

m68k/mac: Make SCC reset work more reliably

2016-01-25T14:15:34+00:00

commit 56931d73697c99ecf7aba6ae86c94d3a2d15d596 upstream.

For SCC initialization we cannot assume that the control register is in
the correct state to accept a register pointer. So first read from the
control register in order to "sync" up.

Signed-off-by: Finn Thain 
Signed-off-by: Geert Uytterhoeven 
Cc: Oliver Neukum 
Signed-off-by: Jiri Slaby

m68k/mm: Check for mm != NULL in do_page_fault() debug code

2016-01-25T14:15:34+00:00

commit 4e25c0e92f8eaf69bc51d1d523bcb7268e7dd162 upstream.

When DEBUG is enabled, do_page_fault() may dereference a NULL pointer,
causing recursive bus errors.

Signed-off-by: Geert Uytterhoeven 
Cc: Oliver Neukum 
Signed-off-by: Jiri Slaby

m68k: Define asmlinkage_protect

2015-10-28T15:38:07+00:00

commit 8474ba74193d302e8340dddd1e16c85cc4b98caf upstream.

Make sure the compiler does not modify arguments of syscall functions.
This can happen if the compiler generates a tailcall to another
function.  For example, without asmlinkage_protect sys_openat is compiled
into this function:

sys_openat:
	clr.l %d0
	move.w 18(%sp),%d0
	move.l %d0,16(%sp)
	jbra do_sys_open

Note how the fourth argument is modified in place, modifying the register
%d4 that gets restored from this stack slot when the function returns to
user-space.  The caller may expect the register to be unmodified across
system calls.

Signed-off-by: Andreas Schwab 
Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Jiri Slaby

arch: Clean up asm/barrier.h implementations using asm-generic/barrier.h

2015-10-28T15:37:39+00:00

commit 93ea02bb84354370e51de803a9405f171f3edf88 upstream.

We're going to be adding a few new barrier primitives, and in order to
avoid endless duplication make more agressive use of
asm-generic/barrier.h.

Change the asm-generic/barrier.h such that it allows partial barrier
definitions and fills out the rest with defaults.

There are a few architectures (m32r, m68k) that could probably
do away with their barrier.h file entirely but are kept for now due to
their unconventional nop() implementation.

Suggested-by: Geert Uytterhoeven 
Reviewed-by: "Paul E. McKenney" 
Reviewed-by: Mathieu Desnoyers 
Signed-off-by: Peter Zijlstra 
Cc: Michael Ellerman 
Cc: Michael Neuling 
Cc: Russell King 
Cc: Heiko Carstens 
Cc: Linus Torvalds 
Cc: Martin Schwidefsky 
Cc: Victor Kaplansky 
Cc: Tony Luck 
Cc: Oleg Nesterov 
Cc: Benjamin Herrenschmidt 
Cc: Frederic Weisbecker 
Link: http://lkml.kernel.org/r/20131213150640.846368594@infradead.org
Signed-off-by: Ingo Molnar 
Signed-off-by: Jiri Slaby

m68k/mac: Fix out-of-bounds array index in OSS IRQ source initialization

2015-06-10T13:20:27+00:00

commit b24f670b7f5b2058b95370caa9f104b3cefb9f1d upstream.

Reported-by: David Binderman 
Signed-off-by: Finn Thain 
Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Jiri Slaby

vm: add VM_FAULT_SIGSEGV handling support

2015-03-12T16:31:25+00:00

commit 33692f27597fcab536d7cbbcc8f52905133e4aa7 upstream.

The core VM already knows about VM_FAULT_SIGBUS, but cannot return a
"you should SIGSEGV" error, because the SIGSEGV case was generally
handled by the caller - usually the architecture fault handler.

That results in lots of duplication - all the architecture fault
handlers end up doing very similar "look up vma, check permissions, do
retries etc" - but it generally works.  However, there are cases where
the VM actually wants to SIGSEGV, and applications _expect_ SIGSEGV.

In particular, when accessing the stack guard page, libsigsegv expects a
SIGSEGV.  And it usually got one, because the stack growth is handled by
that duplicated architecture fault handler.

However, when the generic VM layer started propagating the error return
from the stack expansion in commit fee7e49d4514 ("mm: propagate error
from stack expansion even for guard page"), that now exposed the
existing VM_FAULT_SIGBUS result to user space.  And user space really
expected SIGSEGV, not SIGBUS.

To fix that case, we need to add a VM_FAULT_SIGSEGV, and teach all those
duplicate architecture fault handlers about it.  They all already have
the code to handle SIGSEGV, so it's about just tying that new return
value to the existing code, but it's all a bit annoying.

This is the mindless minimal patch to do this.  A more extensive patch
would be to try to gather up the mostly shared fault handling logic into
one generic helper routine, and long-term we really should do that
cleanup.

Just from this patch, you can generally see that most architectures just
copied (directly or indirectly) the old x86 way of doing things, but in
the meantime that original x86 model has been improved to hold the VM
semaphore for shorter times etc and to handle VM_FAULT_RETRY and other
"newer" things, so it would be a good idea to bring all those
improvements to the generic case and teach other architectures about
them too.

Reported-and-tested-by: Takashi Iwai 
Tested-by: Jan Engelhardt 
Acked-by: Heiko Carstens  # "s390 still compiles and boots"
Cc: linux-arch@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds 
Signed-off-by: Jiri Slaby

m68k: Disable/restore interrupts in hwreg_present()/hwreg_write()

2014-10-31T14:11:16+00:00

commit e4dc601bf99ccd1c95b7e6eef1d3cf3c4b0d4961 upstream.

hwreg_present() and hwreg_write() temporarily change the VBR register to
another vector table. This table contains a valid bus error handler
only, all other entries point to arbitrary addresses.

If an interrupt comes in while the temporary table is active, the
processor will start executing at such an arbitrary address, and the
kernel will crash.

While most callers run early, before interrupts are enabled, or
explicitly disable interrupts, Finn Thain pointed out that macsonic has
one callsite that doesn't, causing intermittent boot crashes.
There's another unsafe callsite in hilkbd.

Fix this for good by disabling and restoring interrupts inside
hwreg_present() and hwreg_write().

Explicitly disabling interrupts can be removed from the callsites later.

Reported-by: Finn Thain 
Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Jiri Slaby

m68k: Skip futex_atomic_cmpxchg_inatomic() test

2014-04-13T14:41:27+00:00

commit e571c58f313d35c56e0018470e3375ddd1fd320e upstream.

Skip the futex_atomic_cmpxchg_inatomic() test in futex_init(). It causes a
fatal exception on 68030 (and presumably 68020 also).

Signed-off-by: Finn Thain 
Acked-by: Geert Uytterhoeven 
Link: http://lkml.kernel.org/r/alpine.LNX.2.00.1403061006440.5525@nippy.intranet
Signed-off-by: Thomas Gleixner 
Signed-off-by: Jiri Slaby

Remove GENERIC_HARDIRQ config option

2013-09-13T13:09:52+00:00

After the last architecture switched to generic hard irqs the config
options HAVE_GENERIC_HARDIRQS & GENERIC_HARDIRQS and the related code
for !CONFIG_GENERIC_HARDIRQS can be removed.

Signed-off-by: Martin Schwidefsky