linux-toradex.git/mm/percpu.c, branch v3.4.73

kmemleak: Fix the kmemleak tracking of the percpu areas with !SMP

2012-05-09T17:13:29+00:00

Kmemleak tracks the percpu allocations via a specific API and the
originally allocated areas must be removed from kmemleak (via
kmemleak_free). The code was already doing this for SMP systems.

Reported-by: Sami Liedes 
Cc: Tejun Heo 
Cc: Christoph Lameter 
Signed-off-by: Catalin Marinas 
Signed-off-by: Tejun Heo

percpu: pcpu_embed_first_chunk() should free unused parts after all allocs are complete

2012-05-09T17:08:16+00:00

pcpu_embed_first_chunk() allocates memory for each node, copies percpu
data and frees unused portions of it before proceeding to the next
group.  This assumes that allocations for different nodes doesn't
overlap; however, depending on memory topology, the bootmem allocator
may end up allocating memory from a different node than the requested
one which may overlap with the portion freed from one of the previous
percpu areas.  This leads to percpu groups for different nodes
overlapping which is a serious bug.

This patch separates out copy & partial free from the allocation loop
such that all allocations are complete before partial frees happen.

This also fixes overlapping frees which could happen on allocation
failure path - out_free_areas path frees whole groups but the groups
could have portions freed at that point.

Signed-off-by: Tejun Heo 
Cc: stable@vger.kernel.org
Reported-by: "Pavel V. Panteleev" 
Tested-by: "Pavel V. Panteleev" 
LKML-Reference:

percpu: use KERN_CONT in pcpu_dump_alloc_info()

2012-03-29T16:45:58+00:00

pcpu_dump_alloc_info() was printing continued lines without KERN_CONT.
Use it.

Signed-off-by: Tejun Heo 
Reported-by: Kay Sievers

Merge tag 'kmemleak' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux

2012-01-15T02:11:11+00:00

Kmemleak patches

Main features:
- Handle percpu memory allocations (only scanning them, not actually
  reporting).
- Memory hotplug support.

Usability improvements:
- Show the origin of early allocations.
- Report previously found leaks even if kmemleak has been disabled by
  some error.

* tag 'kmemleak' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux:
  kmemleak: Add support for memory hotplug
  kmemleak: Handle percpu memory allocation
  kmemleak: Report previously found leaks even after an error
  kmemleak: When the early log buffer is exceeded, report the actual number
  kmemleak: Show where early_log issues come from

percpu: fix per_cpu_ptr_to_phys() handling of non-page-aligned addresses

2011-12-15T19:41:40+00:00

per_cpu_ptr_to_phys() incorrectly rounds up its result for non-kmalloc
case to the page boundary, which is bogus for any non-page-aligned
address.

This affects the only in-tree user of this function - sysfs handler
for per-cpu 'crash_notes' physical address.  The trouble is that the
crash_notes per-cpu variable is not page-aligned:

crash_notes = 0xc08e8ed4
PER-CPU OFFSET VALUES:
 CPU 0: 3711f000
 CPU 1: 37129000
 CPU 2: 37133000
 CPU 3: 3713d000

So, the per-cpu addresses are:
 crash_notes on CPU 0: f7a07ed4 => phys 36b57ed4
 crash_notes on CPU 1: f7a11ed4 => phys 36b4ded4
 crash_notes on CPU 2: f7a1bed4 => phys 36b43ed4
 crash_notes on CPU 3: f7a25ed4 => phys 36b39ed4

However, /sys/devices/system/cpu/cpu*/crash_notes says:
 /sys/devices/system/cpu/cpu0/crash_notes: 36b57000
 /sys/devices/system/cpu/cpu1/crash_notes: 36b4d000
 /sys/devices/system/cpu/cpu2/crash_notes: 36b43000
 /sys/devices/system/cpu/cpu3/crash_notes: 36b39000

As you can see, all values are rounded down to a page
boundary. Consequently, this is where kexec sets up the NOTE segments,
and thus where the secondary kernel is looking for them. However, when
the first kernel crashes, it saves the notes to the unaligned
addresses, where they are not found.

Fix it by adding offset_in_page() to the translated page address.

-tj: Combined Eugene's and Petr's commit messages.

Signed-off-by: Eugene Surovegin 
Signed-off-by: Tejun Heo 
Reported-by: Petr Tesarik 
Cc: stable@kernel.org

kmemleak: Handle percpu memory allocation

2011-12-02T16:12:42+00:00

This patch adds kmemleak callbacks from the percpu allocator, reducing a
number of false positives caused by kmemleak not scanning such memory
blocks. The percpu chunks are never reported as leaks because of current
kmemleak limitations with the __percpu pointer not pointing directly to
the actual chunks.

Reported-by: Huajun Li 
Acked-by: Christoph Lameter 
Acked-by: Tejun Heo 
Signed-off-by: Catalin Marinas

percpu: explain why per_cpu_ptr_to_phys() is more complicated than necessary

2011-11-23T16:20:53+00:00

Add comments about current per_cpu_ptr_to_phys implementation to
explain why the logic is more complicated than necessary.

-tj: relocated comment into kerneldoc comment

Signed-off-by: Dave Young 
Signed-off-by: Tejun Heo

percpu: fix chunk range calculation

2011-11-22T16:09:46+00:00

Percpu allocator recorded the cpus which map to the first and last
units in pcpu_first/last_unit_cpu respectively and used them to
determine the address range of a chunk - e.g. it assumed that the
first unit has the lowest address in a chunk while the last unit has
the highest address.

This simply isn't true.  Groups in a chunk can have arbitrary positive
or negative offsets from the previous one and there is no guarantee
that the first unit occupies the lowest offset while the last one the
highest.

Fix it by actually comparing unit offsets to determine cpus occupying
the lowest and highest offsets.  Also, rename pcu_first/last_unit_cpu
to pcpu_low/high_unit_cpu to avoid confusion.

The chunk address range is used to flush cache on vmalloc area
map/unmap and decide whether a given address is in the first chunk by
per_cpu_ptr_to_phys() and the bug was discovered by invalid
per_cpu_ptr_to_phys() translation for crash_note.

Kudos to Dave Young for tracking down the problem.

Signed-off-by: Tejun Heo 
Reported-by: WANG Cong 
Reported-by: Dave Young 
Tested-by: Dave Young 
LKML-Reference: <4EC21F67.10905@redhat.com>
Cc: stable @kernel.org

percpu: rename pcpu_mem_alloc to pcpu_mem_zalloc

2011-11-22T16:09:41+00:00

Currently pcpu_mem_alloc() is implemented always return zeroed memory.
So rename it to make user like pcpu_get_pages_and_bitmap() know don't
reinit it.

Signed-off-by: Bob Liu 
Reviewed-by: Pekka Enberg 
Reviewed-by: Michal Hocko 
Signed-off-by: Tejun Heo

Merge branch 'for-2.6.40' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu

2011-05-24T18:53:42+00:00

* 'for-2.6.40' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  percpu: Unify input section names
  percpu: Avoid extra NOP in percpu_cmpxchg16b_double
  percpu: Cast away printk format warning
  percpu: Always align percpu output section to PAGE_SIZE

Fix up fairly trivial conflict in arch/x86/include/asm/percpu.h as per Tejun