9 Commits

Author	SHA1	Message	Date
Petro Karashchenko	5a298e8685	mm: memory allocations return valid pointer when request 0 size ... This change introduce 2 items: 1. If the size of the space requested is 0, the behavior is implementation-defined: either a null pointer shall be returned, or the behavior shall be as if the size were some non-zero value, except that the behavior is undefined if the returned pointer is used to access an object. Change the behavior to be similar to Linux and Android and allocates an object of a minimum size instead of returning null pointer. https://pubs.opengroup.org/onlinepubs/9699919799/functions/malloc.html https://pubs.opengroup.org/onlinepubs/9699919799/functions/calloc.html https://pubs.opengroup.org/onlinepubs/9699919799/functions/realloc.html 2. The description of realloc() has been modified from previous versions of this standard to align with the ISO/IEC 9899:1999 standard. Previous versions explicitly permitted a call to realloc (p, 0) to free the space pointed to by p and return a null pointer. While this behavior could be interpreted as permitted by this version of the standard, the C language committee have indicated that this interpretation is incorrect. Applications should assume that if realloc() returns a null pointer, the space pointed to by p has not been freed. Since this could lead to double-frees, implementations should also set errno if a null pointer actually indicates a failure, and applications should only free the space if errno was changed. Do not free memory of zero-length reallocation is requested https://pubs.opengroup.org/onlinepubs/9699919799/functions/realloc.html Co-authored-by: fangxinyong <fangxinyong@xiaomi.com> Signed-off-by: Petro Karashchenko <petro.karashchenko@gmail.com>	2023-05-02 18:29:29 -06:00
mage1	def007e2d7	add #undef for some libc function ... since it's useful to redirect these functions to others sometime(e.g. validate the memory before write). Change-Id: I6253a9231af8809e8362f4bc5a1bd67fb094c3b0	2021-07-14 15:09:58 -03:00
Xiang Xiao	76cdd5c329	mm: Remove mm_heap_impl_s struct ... it's more simple to make mm_heap_s opaque outside of mm Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com> Change-Id: I5c8e435f6baba6d22b10c5f7e8d9191104fb5af2	2021-07-07 04:25:15 -07:00
Alin Jerpelea	bcee9c391c	mm: Author Gregory Nutt: update licenses to Apache ... Gregory Nutt has submitted the SGA and we can mograte the licenses to Apache. Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>	2021-02-09 01:21:53 -08:00
Gregory Nutt	90e4cf4349	mm/umm_heap: sbrk() is only available in the KERNEL build.	2019-02-04 10:32:31 -06:00
Xiang Xiao	2671709e62	mm/umm_heap: Ensure all user allocation try sbrk before fail	2019-01-26 10:42:36 -06:00
Gregory Nutt	59cc4a7a7b	Protected mode: Redesign how the user space heap is accessed from the kernel code. It used to call memory management functions in user space via function pointers in the userspace interface. That is inefficient because the first thing that those memory management functions do is to trap back into the kernel to get the current PID. Worse, that operation can be fatal is certain fragile situations such as when a task is exitting. ... The solution is to remove all of the memory management function calls from the interface. Instead, the interface exports the userspace heap structure and then kernel size implementations of those memory management functions will operate on the userspace heap structure. This avoids the unnecessary system calls and, more importantly, failures do to freeing memory when a test exits.	2015-07-10 08:37:02 -06:00
Gregory Nutt	b33c2d9cef	Move include/nuttx/mm.h to include/nuttx/mm/mm.h	2014-09-24 07:29:09 -06:00
Gregory Nutt	8b8c134efa	Move the user heap allocator front-end from mm/. to mm/umm_heap/.	2014-09-22 10:48:58 -06:00