user/sven/linux.git/lib/flex_array.c, branch v3.4.46

lib: reduce the use of module.h wherever possible

2012-03-07T20:04:04Z

For files only using THIS_MODULE and/or EXPORT_SYMBOL, map them onto including export.h -- or if the file isn't even using those, then just delete the include. Fix up any implicit include dependencies that were being masked by module.h along the way. Signed-off-by: Paul Gortmaker

flex_array: avoid divisions when accessing elements

2011-05-27T00:12:33Z

On most architectures division is an expensive operation and accessing an element currently requires four of them. This performance penalty effectively precludes flex arrays from being used on any kind of fast path. However, two of these divisions can be handled at creation time and the others can be replaced by a reciprocal divide, completely avoiding real divisions on access. [eparis@redhat.com: rebase on top of changes to support 0 len elements] [eparis@redhat.com: initialize part_nr when array fits entirely in base] Signed-off-by: Jesse Gross Signed-off-by: Eric Paris Cc: Dave Hansen Cc: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

flex_array: allow 0 length elements

2011-04-28T19:56:07Z

flex_arrays are supposed to be a replacement for: kmalloc(num_elements * sizeof(element)) If kmalloc is given 0 num_elements or a 0 size element it will happily return ZERO_SIZE_PTR. Which looks like a valid allocation, but which will explode if something actually try to use it. The current flex_array code will return an equivalent result if num_elements is 0, but will fail to work if sizeof(element) is 0. This patch allows allocation to work even for 0 size elements. It will cause flex_arrays to explode though if they are used. Imitating the kmalloc behavior. Based-on-patch-by: Steffen Klassert Signed-off-by: Eric Paris Acked-by: Dave Hansen

flex_arrays: allow zero length flex arrays

2011-04-28T19:56:07Z

Just like kmalloc will allow one to allocate a 0 length segment of memory flex arrays should do the same thing. It should bomb if you try to use something, but it should at least allow the allocation. This is needed because when SELinux switched to using flex_arrays in 2.6.38 the inability to allocate a 0 length array resulted in SELinux policy load returning -ENOSPC when previously it worked. Based-on-patch-by: Steffen Klassert Signed-off-by: Eric Paris Tested-by: Chris Richards Cc: stable@kernel.org [2.6.38+]

flex_array: flex_array_prealloc takes a number of elements, not an end

2011-04-28T19:56:06Z

Change flex_array_prealloc to take the number of elements for which space should be allocated instead of the last (inclusive) element. Users and documentation are updated accordingly. flex_arrays got introduced before they had users. When folks started using it, they ended up needing a different API than was coded up originally. This swaps over to the API that folks apparently need. Based-on-patch-by: Steffen Klassert Signed-off-by: Eric Paris Tested-by: Chris Richards Acked-by: Dave Hansen Cc: stable@kernel.org [2.6.38+]

flex_array: export symbols to modules

2011-01-13T16:03:11Z

Alex said: I want to use flex_array to store a sparse array of ATM cell re-assembly buffers for my ATM over Ethernet driver. Using the per-vcc user_back structure causes problems when stacked with things like br2684. Add EXPORT_SYMBOL() for all publically accessible flex array functions and move to obj-y so that modules may use this library. Signed-off-by: David Rientjes Cc: Dave Hansen Cc: Paul Mundt Reported-by: Alex Bennee Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

flex_array: add helpers to get and put to make pointers easy to use

2010-08-10T03:45:09Z

Getting and putting arrays of pointers with flex arrays is a PITA. You have to remember to pass &ptr to the _put and you have to do weird and wacky casting to get the ptr back from the _get. Add two functions flex_array_get_ptr() and flex_array_put_ptr() to handle all of the magic. [akpm@linux-foundation.org: simplification suggested by Joe] Signed-off-by: Eric Paris Cc: David Rientjes Cc: Dave Hansen Cc: Joe Perches Cc: James Morris Cc: Joe Perches Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

flex_array: fix the panic when calling flex_array_alloc() without __GFP_ZERO

2010-04-24T18:31:24Z

memset() is called with the wrong address and the kernel panics. Signed-off-by: Changli Gao Cc: Patrick McHardy Acked-by: David Rientjes Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

flex_array: add missing kerneldoc annotations

2009-09-22T14:17:47Z

Add kerneldoc annotations for function formals of type struct flex_array and gfp_t which are currently lacking. Signed-off-by: David Rientjes Cc: Dave Hansen Cc: Randy Dunlap Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

flex_array: introduce DEFINE_FLEX_ARRAY

2009-09-22T14:17:47Z

FLEX_ARRAY_INIT(element_size, total_nr_elements) cannot determine if either parameter is valid, so flex arrays which are statically allocated with this interface can easily become corrupted or reference beyond its allocated memory. This removes FLEX_ARRAY_INIT() as a struct flex_array initializer since no initializer may perform the required checking. Instead, the array is now defined with a new interface: DEFINE_FLEX_ARRAY(name, element_size, total_nr_elements) This may be prefixed with `static' for file scope. This interface includes compile-time checking of the parameters to ensure they are valid. Since the validity of both element_size and total_nr_elements depend on FLEX_ARRAY_BASE_SIZE and FLEX_ARRAY_PART_SIZE, the kernel build will fail if either of these predefined values changes such that the array parameters are no longer valid. Since BUILD_BUG_ON() requires compile time constants, several of the static inline functions that were once local to lib/flex_array.c had to be moved to include/linux/flex_array.h. Signed-off-by: David Rientjes Acked-by: Dave Hansen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds