linux-toradex.git/arch/s390, branch tegra

oprofile: Fix uninitialized memory access when writing to writing to oprofilefs

2012-01-11T17:30:03+00:00

commit 913050b91eb94f194392dd797b1ff3779f606ac0 upstream.

If oprofilefs_ulong_from_user() is called with count equals
zero, *val remains unchanged. Depending on the implementation it
might be uninitialized.

Change oprofilefs_ulong_from_user()'s interface to return count
on success. Thus, we are able to return early if count equals
zero which avoids using *val uninitialized. Fixing all users of
oprofilefs_ulong_ from_user().

This follows write syscall implementation when count is zero:
"If count is zero ... [and if] no errors are detected, 0 will be
returned without causing any other effect." (man 2 write)

Reported-By: Mike Waychison 
Signed-off-by: Robert Richter 
Cc: Andrew Morton 
Cc: oprofile-list 
Link: http://lkml.kernel.org/r/20111219153830.GH16765@erda.amd.com
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman 

Change-Id: Ic9b5dd12ec6e93b609b0e61acd02944352cd436d
Reviewed-on: http://git-master/r/74177
Reviewed-by: Varun Wadekar 
Tested-by: Varun Wadekar

cpu-hotplug: CPUx should be active before it is marked online

2011-12-27T05:28:19+00:00

CPU0		CPUn

_cpu_up()
  __cpu_up()

		boostrap()
		  notify_cpu_starting()
		  set_cpu_online()
		  while (!cpu_active())
		    cpu_relax()



smp_call_function(.wait=1)
  /* we find cpu_online() is true */
  arch_send_call_function_ipi_mask()
  /* wait-forever-more */

		  local_irq_enable()

  cpu_notify(CPU_ONLINE)
    sched_cpu_active()
      set_cpu_active()

Now the purpose of cpu_active is mostly with bringing down a cpu, where
we mark it !active to avoid the load-balancer from moving tasks to it
while we tear down the cpu. This is required because we only update the
sched_domain tree after we brought the cpu-down. And this is needed so
that some tasks can still run while we bring it down, we just don't want
new tasks to appear.

On cpu-up however the sched_domain tree doesn't yet include the new cpu,
so its invisible to the load-balancer, regardless of the active state.
So instead of setting the active state after we boot the new cpu (and
consequently having to wait for it before enabling interrupts) set the
cpu active before we set it online and avoid the whole mess.

Bug 916986

Original Patch: https://lkml.org/lkml/2011/12/15/255

Change-Id: Ia1c07bdc1b3eb07a7cd4d69756fa7bec509c9400
Reported-by: Stepan Moskovchenko 
Signed-off-by: Peter Zijlstra 
Signed-off-by: Varun Wadekar 
Reviewed-on: http://git-master/r/72130
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Mayuresh Kulkarni

add missing .set function for NT_S390_LAST_BREAK regset

2011-12-09T16:55:45+00:00

commit b934069c991355d27a053a932591c77960f4e414 upstream.

The last breaking event address is a read-only value, the regset misses the
.set function. If a PTRACE_SETREGSET is done for NT_S390_LAST_BREAK we
get an oops due to a branch to zero:

Kernel BUG at 0000000000000002 verbose debug info unavailable
illegal operation: 0001 #1 SMP
...
Call Trace:
(<0000000000158294> ptrace_regset+0x184/0x188)
 <00000000001595b6> ptrace_request+0x37a/0x4fc
 <0000000000109a78> arch_ptrace+0x108/0x1fc
 <00000000001590d6> SyS_ptrace+0xaa/0x12c
 <00000000005c7a42> sysc_noemu+0x16/0x1c
 <000003fffd5ec10c> 0x3fffd5ec10c
Last Breaking-Event-Address:
 <0000000000158242> ptrace_regset+0x132/0x188

Add a nop .set function to prevent the branch to zero.

Signed-off-by: Martin Schwidefsky 
Signed-off-by: Greg Kroah-Hartman

KVM: s390: Fix RUNNING flag misinterpretation

2011-11-26T17:08:33+00:00

commit 9e6dabeffd1d0ec2aa19aa076c4886067238d442 upstream.

CPUSTAT_RUNNING was implemented signifying that a vcpu is not stopped.
This is not, however, what the architecture says: RUNNING should be
set when the host is acting on the behalf of the guest operating
system.

CPUSTAT_RUNNING has been changed to be set in kvm_arch_vcpu_load()
and to be unset in kvm_arch_vcpu_put().

For signifying stopped state of a vcpu, a host-controlled bit has
been used and is set/unset basically on the reverse as the old
CPUSTAT_RUNNING bit (including pushing it down into stop handling
proper in handle_stop()).

Signed-off-by: Cornelia Huck 
Signed-off-by: Carsten Otte 
Signed-off-by: Avi Kivity 
Signed-off-by: Greg Kroah-Hartman

thp: share get_huge_page_tail()

2011-11-11T17:44:01+00:00

commit b35a35b556f5e6b7993ad0baf20173e75c09ce8c upstream.

This avoids duplicating the function in every arch gup_fast.

Signed-off-by: Andrea Arcangeli 
Cc: Peter Zijlstra 
Cc: Hugh Dickins 
Cc: Johannes Weiner 
Cc: Rik van Riel 
Cc: Mel Gorman 
Cc: KOSAKI Motohiro 
Cc: Benjamin Herrenschmidt 
Cc: David Gibson 
Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
Cc: David Miller 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

s390: gup_huge_pmd() return 0 if pte changes

2011-11-11T17:44:00+00:00

commit 0693bc9ce2cc4f6a1b9c3c05790fc149a74c0b87 upstream.

s390 didn't return 0 in that case, if it's rolling back the *nr pointer it
should also return zero to avoid adding pages to the array at the wrong
offset.

Signed-off-by: Andrea Arcangeli 
Cc: Peter Zijlstra 
Cc: Hugh Dickins 
Cc: Johannes Weiner 
Cc: Rik van Riel 
Cc: Mel Gorman 
Cc: KOSAKI Motohiro 
Cc: Benjamin Herrenschmidt 
Cc: David Gibson 
Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
Cc: David Miller 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

s390: gup_huge_pmd() support THP tail recounting

2011-11-11T17:44:00+00:00

commit 220a2eb228d032acde60e9fd044ca802706ff583 upstream.

Up to this point the code assumed old refcounting for hugepages (pre-thp).
This updates the code directly to the thp mapcount tail page refcounting.

Signed-off-by: Andrea Arcangeli 
Cc: Peter Zijlstra 
Cc: Hugh Dickins 
Cc: Johannes Weiner 
Cc: Rik van Riel 
Cc: Mel Gorman 
Cc: KOSAKI Motohiro 
Cc: Benjamin Herrenschmidt 
Cc: David Gibson 
Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
Cc: David Miller 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

memory leak with RCU_TABLE_FREE

2011-11-11T17:43:22+00:00

commit e73b7fffe487c315fd1a4fa22282e3362b440a06 upstream.

The rcu page table free code uses a couple of bits in the page table
pointer passed to tlb_remove_table to discern the different page table
types. __tlb_remove_table extracts the type with an incorrect mask which
leads to memory leaks. The correct mask is ((FRAG_MASK << 4) | FRAG_MASK).

Signed-off-by: Martin Schwidefsky 
Signed-off-by: Greg Kroah-Hartman

user per registers vs. ptrace single stepping

2011-11-11T17:43:22+00:00

commit a45aff5285871bf7be1781d9462d3fdbb6c913f9 upstream.

git commit 5e9a2692 "[S390] ptrace cleanup" introduced a regression
for the case when both a user PER set (e.g. a storage alteration trace) and
PTRACE_SINGLESTEP are active. The new code will overrule the user PER set
with a instruction-fetch PER set over the whole address space for ptrace
single stepping. The inferior process will be stopped after each instruction
with an instruction fetch event. Any other events that may have occurred
concurrently are not reported (e.g. storage alteration event) because the
control bits for them are not set. The solution is to merge the PER control
bits of the user PER set with the PER_EVENT_IFETCH control bit for
PTRACE_SINGLESTEP.

Signed-off-by: Martin Schwidefsky 
Signed-off-by: Greg Kroah-Hartman

KVM: s390: check cpu_id prior to using it

2011-11-11T17:43:21+00:00

commit 4d47555a80495657161a7e71ec3014ff2021e450 upstream.

We use the cpu id provided by userspace as array index here. Thus we
clearly need to check it first. Ooops.

Signed-off-by: Carsten Otte 
Signed-off-by: Christian Borntraeger 
Signed-off-by: Marcelo Tosatti 
Signed-off-by: Greg Kroah-Hartman