linux-toradex.git/lib, branch v2.6.29

bitmap: fix end condition in bitmap_find_free_region

2009-03-13T02:32:51+00:00

Guennadi Liakhovetski noticed that the end condition for the loop in
bitmap_find_free_region() is wrong, and the "return if error" was also
using the wrong conditional that would only trigger if the bitmap was an
exact multiple of the allocation size, which is not necessarily the case
with dma_alloc_from_coherent().

Such a failure would end up in bitmap_find_free_region() accessing
beyond the end of the bitmap.

Reported-by: Guennadi Liakhovetski 
Cc: Andrew Morton 
Signed-off-by: Linus Torvalds

idr: make idr_remove_all() do removal -before- free_layer()

2009-03-10T22:55:11+00:00

Fix a problem in the IDR system, where an idr_remove_all() hands a data
element to call_rcu() (via free_layer()) before making that data element
inaccessible to new readers.  This is very bad, and results in readers
still having a reference to this data element at the end of the grace
period.

Tests on large machines that concurrently map and unmap user-space memory
within the same multithreaded process result in crashes within about five
minutes.  Applying this patch increases the kernel's longevity to the
three-to-eight-hour range.

There appear to be other similar problems in idr_get_empty_slot() and
sub_remove(), but I fixed the easy one in idr_remove_all() first.  It is
therefore no surprise that failures still occur.

Located-by: Milton Miller II 
Tested-by: Milton Miller II 
Signed-off-by: Paul E. McKenney 
Cc: Manfred Spraul 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

docsrc: use config instead of menuconfig

2009-02-21T01:57:49+00:00

BUILD_DOCSRC should be controlled by "config" instead of "menuconfig".
I have no idea how I managed to use "menuconfig" here.

Signed-off-by: Randy Dunlap 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

cpumask: convert lib/smp_processor_id to new cpumask ops

2009-01-30T14:47:34+00:00

Impact: fix debug_smp_processor_id() for CONFIG_CPUMASK_OFFSTACK=y

The scheduler now uses the new cpumask API, which deals up to
nr_cpumask_bits, whereas the API used NR_CPUS bits.

If CONFIG_CPUMASK_OFFSTACK=y these two are not equal, so the top bits
are undefined.  Leading to bug 12518 "BUG: using smp_processor_id() in
preemptible [00000000] code: dellWirelessCtl/..."

The fix is simple: use the modern API in the check.

Signed-off-by: Rusty Russell 
Signed-off-by: Mike Travis 
Signed-off-by: Ingo Molnar

Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2009-01-26T17:47:56+00:00

* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  debugobjects: add and use INIT_WORK_ON_STACK
  rcu: remove duplicate CONFIG_RCU_CPU_STALL_DETECTOR
  relay: fix lock imbalance in relay_late_setup_files
  oprofile: fix uninitialized use of struct op_entry
  rcu: move Kconfig menu
  softlock: fix false panic which can occur if softlockup_thresh is reduced
  rcu: add __cpuinit to rcu_init_percpu_data()

Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2009-01-26T17:47:28+00:00

* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (29 commits)
  xen: unitialised return value in xenbus_write_transaction
  x86: fix section mismatch warning
  x86: unmask CPUID levels on Intel CPUs, fix
  x86: work around PAGE_KERNEL_WC not getting WC in iomap_atomic_prot_pfn.
  x86: use standard PIT frequency
  xen: handle highmem pages correctly when shrinking a domain
  x86, mm: fix pte_free()
  xen: actually release memory when shrinking domain
  x86: unmask CPUID levels on Intel CPUs
  x86: add MSR_IA32_MISC_ENABLE bits to 
  x86: fix PTE corruption issue while mapping RAM using /dev/mem
  x86: mtrr fix debug boot parameter
  x86: fix page attribute corruption with cpa()
  Revert "x86: signal: change type of paramter for sys_rt_sigreturn()"
  x86: use early clobbers in usercopy*.c
  x86: remove kernel_physical_mapping_init() from init section
  fix: crash: IP: __bitmap_intersects+0x48/0x73
  cpufreq: use work_on_cpu in acpi-cpufreq.c for drv_read and drv_write
  work_on_cpu: Use our own workqueue.
  work_on_cpu: don't try to get_online_cpus() in work_on_cpu.
  ...

Merge branch 'core/debugobjects' into core/urgent

2009-01-22T09:03:02+00:00

rcu: remove duplicate CONFIG_RCU_CPU_STALL_DETECTOR

2009-01-22T08:29:36+00:00

Impact: remove the old CONFIG_RCU_CPU_STALL_DETECTOR

tree_rcu introduce CONFIG_RCU_CPU_STALL_DETECTOR again.

These two are the same exactly except:

 the old one "depends on CLASSIC_RCU"
 the new one "depends on CLASSIC_RCU || TREE_RCU"

This patch remove the old one.

Signed-off-by: Lai Jiangshan 
Signed-off-by: Ingo Molnar

x86: define ARCH_WANT_FRAME_POINTERS

2009-01-18T20:15:10+00:00

Commit da4276b8299a6544dc41ac2485d3ffca5811b3fb changed a dependency
for FRAME_POINTER from X86 to ARCH_WANT_FRAME_POINTERS, but didn't
actually define it.

This patch adds the definition for ARCH_WANT_FRAME_POINTERS. Without it,
FRAME_POINTER can't be enabled on x86.

Signed-off-by: Jeff Mahoney 
Signed-off-by: Ingo Molnar

lib/idr.c: use kmem_cache_zalloc() for the idr_layer cache

2009-01-16T00:39:40+00:00

David points out that the idr_remove_all() function returns unused slabs
to the kmem cache, but needs to zero them first or else they will be
uninitialized upon next use.  This causes crashes which have been observed
in the firewire subsystem.

He fixed this by zeroing the object before freeing it in idr_remove_all().

But we agree that simply removing the constructor and zeroing the object
at allocation time is simpler than relying upon slab constructor machinery
and might even be faster.

This problem was introduced by "idr: make idr_remove rcu-safe" (commit
cf481c20c476ad2c0febdace9ce23f5a4db19582), which was first released in
2.6.27.

There are no known codesites which trigger this bug in 2.6.27 or 2.6.28.
The post-2.6.28 firewire changes are the only known triggerer.

There might of course be not-yet-discovered triggerers in 2.6.27 and
2.6.28, and there might be out-of-tree triggerers which are added to those
kernel versions.  I'll let the -stable guys decide whether they want to
backport this fix.

Reported-by: David Moore 
Cc: Stefan Richter 
Cc: Nadia Derbey 
Cc: Paul E. McKenney 
Cc: Manfred Spraul 
Cc: Kristian Hgsberg 
Acked-by: Pekka Enberg 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds