linux-toradex.git/arch/parisc, branch v3.12.6

parisc: fix mmap(MAP_FIXED|MAP_SHARED) to already mmapped address

2013-12-12T06:37:54+00:00

commit 0576da2c08e3d332f1b0653030d28ab804585ab6 upstream.

locale-gen on Debian showed a strange problem on parisc:
mmap2(NULL, 536870912, PROT_NONE, MAP_SHARED, 3, 0) = 0x42a54000
mmap2(0x42a54000, 103860, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, 3, 0) = -1 EINVAL (Invalid argument)

Basically it was just trying to re-mmap() a file at the same address
which it was given by a previous mmap() call. But this remapping failed
with EINVAL.

The problem is, that when MAP_FIXED and MAP_SHARED flags were used, we didn't
included the mapping-based offset when we verified the alignment of the given
fixed address against the offset which we calculated it in the previous call.

Signed-off-by: Helge Deller 
Signed-off-by: Greg Kroah-Hartman

parisc: break out SOCK_NONBLOCK define to own asm header file

2013-12-04T19:05:11+00:00

commit 38c7937379276a5ea8c54481205003af2f2b5694 upstream.

Break SOCK_NONBLOCK out to its own asm-file as other arches do. This
fixes build errors with auditd and probably other packages.

Signed-off-by: Helge Deller 
Signed-off-by: Greg Kroah-Hartman

parisc: Do not crash 64bit SMP kernels on machines with >= 4GB RAM

2013-10-27T14:58:44+00:00

Since the beginning of the parisc-linux port, sometimes 64bit SMP kernels were
not able to bring up other CPUs than the monarch CPU and instead crashed the
kernel.  The reason was unclear, esp. since it involved various machines (e.g.
J5600, J6750 and SuperDome). Testing showed, that those crashes didn't happened
when less than 4GB were installed, or if a 32bit Linux kernel was booted.

In the end, the fix for those SMP problems is trivial:
During the early phase of the initialization of the CPUs, including the monarch
CPU, the PDC_PSW firmware function to enable WIDE (=64bit) mode is called.
It's documented that this firmware function may clobber various registers, and
one one of those possibly clobbered registers is %cr30 which holds the task
thread info pointer.

Now, if %cr30 would always have been clobbered, then this bug would have been
detected much earlier. But lots of testing finally showed, that - at least for
%cr30 - on some machines only the upper 32bits of the 64bit register suddenly
turned zero after the firmware call.

So, after finding the root cause, the explanation for the various crashes
became clear:
- On 32bit SMP Linux kernels all upper 32bit were zero, so we didn't faced this
  problem.
- Monarch CPUs in 64bit mode always booted sucessfully, because the inital task
  thread info pointer was below 4GB.
- Secondary CPUs booted sucessfully on machines with less than 4GB RAM because
  the upper 32bit were zero anyay.
- Secondary CPus failed to boot if we had more than 4GB RAM and the task thread
  info pointer was located above the 4GB boundary.

Finally, the patch to fix this problem is trivial by saving the %cr30 register
before the firmware call and restoring it afterwards.

Signed-off-by: Helge Deller 
Signed-off-by: John David Anglin 
Cc:  # 2.6.12+
Signed-off-by: Helge Deller

parisc: enable DEVTMPFS, DEVTMPFS_MOUNT and BLK_DEV_INITRD in defconfigs

2013-10-19T19:37:52+00:00

Latest udev requires that DEVTMPFS and DEVTMPFS_MOUNT are enabled, else
initrd will fail to find root filesystem. Enable missing BLK_DEV_INITRD
for B180 and C3000 machines.

Signed-off-by: Helge Deller

Revert "parisc: Export flush_cache_page() (needed by lustre)"

2013-10-19T19:37:40+00:00

This reverts commit 320c90be7ba1c371e882edff57272a89b213d136.

Christoph Hellwig  commented:
This one shouldn't go in - Geert sent it a bit prematurely, as Lustre
shouldn't use it just to reimplement core VM functionality (which it
shouldn't use either, but that's a separate story).

Signed-off-by: Helge Deller

parisc: let probe_kernel_read() capture access to page zero

2013-10-13T15:46:31+00:00

Signed-off-by: Helge Deller

parisc: optimize variable initialization in do_page_fault

2013-10-13T15:45:40+00:00

The attached change defers the initialization of the variables tsk, mm
and flags until they are needed. As a result, the code won't crash if a
kernel probe is done with a corrupt context and the code will be better
optimized.

Signed-off-by: John David Anglin  
Signed-off-by: Helge Deller

parisc: fix interruption handler to respect pagefault_disable()

2013-10-13T15:45:20+00:00

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 
Cc:  # v3.0+
Signed-off-by: John David Anglin  
Signed-off-by: Helge Deller

parisc: mark parisc_terminate() noreturn and cold.

2013-10-13T15:44:49+00:00

Signed-off-by: Helge Deller

parisc: remove unused syscall_ipi() function.

2013-10-13T15:44:39+00:00

Signed-off-by: Helge Deller