linux-toradex.git/arch, branch v3.4.67

parisc: fix interruption handler to respect pagefault_disable()

2013-10-22T08:02:25+00:00

commit 59b33f148cc08fb33cbe823fca1e34f7f023765e upstream.

Running an "echo t > /proc/sysrq-trigger" crashes the parisc kernel.  The
problem is, that in print_worker_info() we try to read the workqueue info via
the probe_kernel_read() functions which use pagefault_disable() to avoid
crashes like this:
    probe_kernel_read(&pwq, &worker->current_pwq, sizeof(pwq));
    probe_kernel_read(&wq, &pwq->wq, sizeof(wq));
    probe_kernel_read(name, wq->name, sizeof(name) - 1);

The problem here is, that the first probe_kernel_read(&pwq) might return zero
in pwq and as such the following probe_kernel_reads() try to access contents of
the page zero which is read protected and generate a kernel segfault.

With this patch we fix the interruption handler to call parisc_terminate()
directly only if pagefault_disable() was not called (in which case
preempt_count()==0).  Otherwise we hand over to the pagefault handler which
will try to look up the faulting address in the fixup tables.

Signed-off-by: Helge Deller 
Signed-off-by: John David Anglin  
Signed-off-by: Helge Deller 
Signed-off-by: Greg Kroah-Hartman

KVM: PPC: Book3S HV: Fix typo in saving DSCR

2013-10-22T08:02:25+00:00

commit cfc860253abd73e1681696c08ea268d33285a2c4 upstream.

This fixes a typo in the code that saves the guest DSCR (Data Stream
Control Register) into the kvm_vcpu_arch struct on guest exit.  The
effect of the typo was that the DSCR value was saved in the wrong place,
so changes to the DSCR by the guest didn't persist across guest exit
and entry, and some host kernel memory got corrupted.

Signed-off-by: Paul Mackerras 
Acked-by: Alexander Graf 
Signed-off-by: Paolo Bonzini 
Signed-off-by: Greg Kroah-Hartman

tile: use a more conservative __my_cpu_offset in CONFIG_PREEMPT

2013-10-13T22:42:50+00:00

commit f862eefec0b68e099a9fa58d3761ffb10bad97e1 upstream.

It turns out the kernel relies on barrier() to force a reload of the
percpu offset value.  Since we can't easily modify the definition of
barrier() to include "tp" as an output register, we instead provide a
definition of __my_cpu_offset as extended assembly that includes a fake
stack read to hazard against barrier(), forcing gcc to know that it
must reread "tp" and recompute anything based on "tp" after a barrier.

This fixes observed hangs in the slub allocator when we are looping
on a percpu cmpxchg_double.

A similar fix for ARMv7 was made in June in change 509eb76ebf97.

Signed-off-by: Chris Metcalf 
Signed-off-by: Greg Kroah-Hartman

mm, show_mem: suppress page counts in non-blockable contexts

2013-10-13T22:42:49+00:00

commit 4b59e6c4730978679b414a8da61514a2518da512 upstream.

On large systems with a lot of memory, walking all RAM to determine page
types may take a half second or even more.

In non-blockable contexts, the page allocator will emit a page allocation
failure warning unless __GFP_NOWARN is specified.  In such contexts, irqs
are typically disabled and such a lengthy delay may even result in NMI
watchdog timeouts.

To fix this, suppress the page walk in such contexts when printing the
page allocation failure warning.

Signed-off-by: David Rientjes 
Cc: Mel Gorman 
Acked-by: Michal Hocko 
Cc: Dave Hansen 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Cc: Xishi Qiu 
Signed-off-by: Greg Kroah-Hartman

sparc32: Fix exit flag passed from traced sys_sigreturn

2013-10-13T22:42:49+00:00

[ Upstream commit 7a3b0f89e3fea680f93932691ca41a68eee7ab5e ]

Pass 1 in %o1 to indicate that syscall_trace accounts exit.

Signed-off-by: Kirill Tkhai 
CC: David Miller 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

sparc64: Fix not SRA'ed %o5 in 32-bit traced syscall

2013-10-13T22:42:49+00:00

[ Upstream commit ab2abda6377723e0d5fbbfe5f5aa16a5523344d1 ]

(From v1 to v2: changed comment)

On the way linux_sparc_syscall32->linux_syscall_trace32->goto 2f,
register %o5 doesn't clear its second 32-bit.

Fix that.

Signed-off-by: Kirill Tkhai 
CC: David Miller 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

sparc64: Fix off by one in trampoline TLB mapping installation loop.

2013-10-13T22:42:49+00:00

[ Upstream commit 63d499662aeec1864ec36d042aca8184ea6a938e ]

Reported-by: Kirill Tkhai 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

sparc64: Remove RWSEM export leftovers

2013-10-13T22:42:49+00:00

[ Upstream commit 61d9b9355b0d427bd1e732bd54628ff9103e496f ]

The functions

			__down_read
			__down_read_trylock
			__down_write
			__down_write_trylock
			__up_read
			__up_write
			__downgrade_write

are implemented inline, so remove corresponding EXPORT_SYMBOLs
(They lead to compile errors on RT kernel).

Signed-off-by: Kirill Tkhai 
CC: David Miller 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

sparc64: Fix ITLB handler of null page

2013-10-13T22:42:49+00:00

[ Upstream commit 1c2696cdaad84580545a2e9c0879ff597880b1a9 ]

1)Use kvmap_itlb_longpath instead of kvmap_dtlb_longpath.

2)Handle page #0 only, don't handle page #1: bleu -> blu

 (KERNBASE is 0x400000, so #1 does not exist too. But everything
  is possible in the future. Fix to not to have problems later.)

3)Remove unused kvmap_itlb_nonlinear.

Signed-off-by: Kirill Tkhai 
CC: David Miller 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

powerpc: Fix parameter clobber in csum_partial_copy_generic()

2013-10-13T22:42:48+00:00

commit d9813c3681a36774b254c0cdc9cce53c9e22c756 upstream.

The csum_partial_copy_generic() uses register r7 to adjust the remaining
bytes to process.  Unfortunately, r7 also holds a parameter, namely the
address of the flag to set in case of access exceptions while reading
the source buffer.  Lacking a quantum implementation of PowerPC, this
commit instead uses register r9 to do the adjusting, leaving r7's
pointer uncorrupted.

Signed-off-by: Paul E. McKenney 
Signed-off-by: Anton Blanchard 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman