linux-toradex.git/include/linux, branch v2.6.38.5

mm: thp: fix /dev/zero MAP_PRIVATE and vm_flags cleanups

2011-05-02T16:19:45+00:00

commit 78f11a255749d09025f54d4e2df4fbcb031530e2 upstream.

The huge_memory.c THP page fault was allowed to run if vm_ops was null
(which would succeed for /dev/zero MAP_PRIVATE, as the f_op->mmap wouldn't
setup a special vma->vm_ops and it would fallback to regular anonymous
memory) but other THP logics weren't fully activated for vmas with vm_file
not NULL (/dev/zero has a not NULL vma->vm_file).

So this removes the vm_file checks so that /dev/zero also can safely use
THP (the other albeit safer approach to fix this bug would have been to
prevent the THP initial page fault to run if vm_file was set).

After removing the vm_file checks, this also makes huge_memory.c stricter
in khugepaged for the DEBUG_VM=y case.  It doesn't replace the vm_file
check with a is_pfn_mapping check (but it keeps checking for VM_PFNMAP
under VM_BUG_ON) because for a is_cow_mapping() mapping VM_PFNMAP should
only be allowed to exist before the first page fault, and in turn when
vma->anon_vma is null (so preventing khugepaged registration).  So I tend
to think the previous comment saying if vm_file was set, VM_PFNMAP might
have been set and we could still be registered in khugepaged (despite
anon_vma was not NULL to be registered in khugepaged) was too paranoid.
The is_linear_pfn_mapping check is also I think superfluous (as described
by comment) but under DEBUG_VM it is safe to stay.

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=33682

Signed-off-by: Andrea Arcangeli 
Reported-by: Caspar Zhang 
Acked-by: Mel Gorman 
Acked-by: Rik van Riel 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

libata: Implement ATA_FLAG_NO_DIPM and apply it to mcp65

2011-05-02T16:19:39+00:00

commit ae01b2493c3bf03c504c32ac4ebb01d528508db3 upstream.

NVIDIA mcp65 familiy of controllers cause command timeouts when DIPM
is used.  Implement ATA_FLAG_NO_DIPM and apply it.

This problem was reported by Stefan Bader in the following thread.

 http://thread.gmane.org/gmane.linux.ide/48841

stable: applicable to 2.6.37 and 38.

Signed-off-by: Tejun Heo 
Reported-by: Stefan Bader 
Signed-off-by: Jeff Garzik 
Signed-off-by: Greg Kroah-Hartman

next_pidmap: fix overflow condition

2011-04-21T21:32:52+00:00

commit c78193e9c7bcbf25b8237ad0dec82f805c4ea69b upstream.

next_pidmap() just quietly accepted whatever 'last' pid that was passed
in, which is not all that safe when one of the users is /proc.

Admittedly the proc code should do some sanity checking on the range
(and that will be the next commit), but that doesn't mean that the
helper functions should just do that pidmap pointer arithmetic without
checking the range of its arguments.

So clamp 'last' to PID_MAX_LIMIT.  The fact that we then do "last+1"
doesn't really matter, the for-loop does check against the end of the
pidmap array properly (it's only the actual pointer arithmetic overflow
case we need to worry about, and going one bit beyond isn't going to
overflow).

[ Use PID_MAX_LIMIT rather than pid_max as per Eric Biederman ]

Reported-by: Tavis Ormandy 
Analyzed-by: Robert Święcki 
Cc: Eric W. Biederman 
Cc: Pavel Emelyanov 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

brk: COMPAT_BRK: fix detection of randomized brk

2011-04-21T21:32:49+00:00

commit 4471a675dfc7ca676c165079e91c712b09dc9ce4 upstream.

5520e89 ("brk: fix min_brk lower bound computation for COMPAT_BRK")
tried to get the whole logic of brk randomization for legacy
(libc5-based) applications finally right.

It turns out that the way to detect whether brk has actually been
randomized in the end or not introduced by that patch still doesn't work
for those binaries, as reported by Geert:

: /sbin/init from my old m68k ramdisk exists prematurely.
:
: Before the patch:
:
: | brk(0x80005c8e)                         = 0x80006000
:
: After the patch:
:
: | brk(0x80005c8e)                         = 0x80005c8e
:
: Old libc5 considers brk() to have failed if the return value is not
: identical to the requested value.

I don't like it, but currently see no better option than a bit flag in
task_struct to catch the CONFIG_COMPAT_BRK && randomize_va_space == 2
case.

Signed-off-by: Jiri Kosina 
Tested-by: Geert Uytterhoeven 
Reported-by: Geert Uytterhoeven 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

kstrto*: converting strings to integers done (hopefully) right

2011-04-21T21:32:41+00:00

commit 33ee3b2e2eb9b4b6c64dcf9ed66e2ac3124e748c upstream.

1. simple_strto*() do not contain overflow checks and crufty,
   libc way to indicate failure.
2. strict_strto*() also do not have overflow checks but the name and
   comments pretend they do.
3. Both families have only "long long" and "long" variants,
   but users want strtou8()
4. Both "simple" and "strict" prefixes are wrong:
   Simple doesn't exactly say what's so simple, strict should not exist
   because conversion should be strict by default.

The solution is to use "k" prefix and add convertors for more types.
Enter
	kstrtoull()
	kstrtoll()
	kstrtoul()
	kstrtol()
	kstrtouint()
	kstrtoint()

	kstrtou64()
	kstrtos64()
	kstrtou32()
	kstrtos32()
	kstrtou16()
	kstrtos16()
	kstrtou8()
	kstrtos8()

Include runtime testsuite (somewhat incomplete) as well.

strict_strto*() become deprecated, stubbed to kstrto*() and
eventually will be removed altogether.

Use kstrto*() in code today!

Note: on some archs _kstrtoul() and _kstrtol() are left in tree, even if
      they'll be unused at runtime. This is temporarily solution,
      because I don't want to hardcode list of archs where these
      functions aren't needed. Current solution with sizeof() and
      __alignof__ at least always works.

Signed-off-by: Alexey Dobriyan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

perf: Fix task context scheduling

2011-04-21T21:32:25+00:00

commit ab711fe08297de1485fff0a366e6db8828cafd6a upstream.

Jiri reported:

 |
 | - once an event is created by sys_perf_event_open, task context
 |   is created and it stays even if the event is closed, until the
 |   task is finished ... thats what I see in code and I assume it's
 |   correct
 |
 | - when the task opens event, perf_sched_events jump label is
 |   incremented and following callbacks are started from scheduler
 |
 |         __perf_event_task_sched_in
 |         __perf_event_task_sched_out
 |
 |   These callback *in/out set/unset cpuctx->task_ctx value to the
 |   task context.
 |
 | - close is called on event on CPU 0:
 |         - the task is scheduled on CPU 0
 |         - __perf_event_task_sched_in is called
 |         - cpuctx->task_ctx is set
 |         - perf_sched_events jump label is decremented and == 0
 |         - __perf_event_task_sched_out is not called
 |         - cpuctx->task_ctx on CPU 0 stays set
 |
 | - exit is called on CPU 1:
 |         - the task is scheduled on CPU 1
 |         - perf_event_exit_task is called
 |         - task_ctx_sched_out unsets cpuctx->task_ctx on CPU 1
 |         - put_ctx destroys the context
 |
 | - another call of perf_rotate_context on CPU 0 will use invalid
 |   task_ctx pointer, and eventualy panic.
 |

Cure this the simplest possibly way by partially reverting the
jump_label optimization for the sched_out case.

Reported-and-tested-by: Jiri Olsa 
Signed-off-by: Peter Zijlstra 
Cc: Oleg Nesterov 
LKML-Reference: <1301520405.4859.213.camel@twins>
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

atm/solos-pci: Don't flap VCs when carrier state changes

2011-04-14T20:02:39+00:00

commit c031235b395433350f25943b7580a5e343c7b7b2 upstream.

Don't flap VCs when carrier state changes; higher-level protocols
can detect loss of connectivity and act accordingly. This is more
consistent with how other network interfaces work.

We no longer use release_vccs() so we can delete it.

release_vccs() was duplicated from net/atm/common.c; make the
corresponding function exported, since other code duplicates it
and could leverage it if it were public.

Signed-off-by: Philip A. Prindeville 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: fix ethtool->set_flags not intended -EINVAL return value

2011-04-14T20:02:11+00:00

commit 673e63c688f43104c73aad8ea4237f7ad41fa14d upstream.

After commit d5dbda23804156ae6f35025ade5307a49d1db6d7 "ethtool: Add
support for vlan accleration.", drivers that have NETIF_F_HW_VLAN_TX,
and/or NETIF_F_HW_VLAN_RX feature, but do not allow enable/disable vlan
acceleration via ethtool set_flags, always return -EINVAL from that
function. Fix by returning -EINVAL only if requested features do not
match current settings and can not be changed by driver.

Change any driver that define ethtool->set_flags to use
ethtool_invalid_flags() to avoid similar problems in the future
(also on drivers that do not have the problem).

Tested with modified (to reproduce this bug) myri10ge driver.

Signed-off-by: Stanislaw Gruszka 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

PCI/ACPI: Report ASPM support to BIOS if not disabled from command line

2011-04-14T20:02:00+00:00

commit 8b8bae901ce23addbdcdb54fa1696fb2d049feb5 upstream.

We need to distinguish the situation in which ASPM support is
disabled from the command line or through .config from the situation
in which it is disabled, because the hardware or BIOS can't handle
it.  In the former case we should not report ASPM support to the BIOS
through ACPI _OSC, but in the latter case we should do that.

Introduce pcie_aspm_support_enabled() that can be used by
acpi_pci_root_add() to determine whether or not it should report ASPM
support to the BIOS through _OSC.

References: https://bugzilla.kernel.org/show_bug.cgi?id=29722
References: https://bugzilla.kernel.org/show_bug.cgi?id=20232
Reported-and-tested-by: Ortwin Glück 
Reviewed-by: Kenji Kaneshige 
Tested-by: Kenji Kaneshige 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Jesse Barnes 
Signed-off-by: Greg Kroah-Hartman

mm: PageBuddy and mapcount robustness

2011-03-27T18:35:58+00:00

commit ef2b4b95a63a1d23958dcb99eb2c6898eddc87d0 upstream.

Change the _mapcount value indicating PageBuddy from -2 to -128 for
more robusteness against page_mapcount() undeflows.

Use reset_page_mapcount instead of __ClearPageBuddy in bad_page to
ignore the previous retval of PageBuddy().

Signed-off-by: Andrea Arcangeli 
Reported-by: Hugh Dickins 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman