move misc/mempool.h to sys/mempool.h and
create a shim for backward-compatibility.
No functional changes to the headers.
A warning in the shim can be controlled with CONFIG_COMPAT_INCLUDES.
Related to #16539
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
move misc/mempool_base.h to sys/mempool_base.h and
create a shim for backward-compatibility.
No functional changes to the headers.
A warning in the shim can be controlled with CONFIG_COMPAT_INCLUDES.
Related to #16539
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
In z_sys_mem_pool_block_alloc() the size of the first level block
allocation is rounded up to the next 4-bite boundary. This means one
or more of the trailing blocks could overlap the free block bitmap.
Let's consider this code from kernel.h:
#define K_MEM_POOL_DEFINE(name, minsz, maxsz, nmax, align) \
char __aligned(align) _mpool_buf_##name[_ALIGN4(maxsz * nmax) \
+ _MPOOL_BITS_SIZE(maxsz, minsz, nmax)]; \
The static pool allocation rounds up the product of maxsz and nmax not
size of individual blocks. If we have, say maxsz = 10 and nmax = 20,
the result of _ALIGN4(10 * 20) is 200. That's the offset at which the
free block bitmap will be located.
However, because z_sys_mem_pool_block_alloc() does this:
lsizes[0] = _ALIGN4(p->max_sz);
Individual level 0 blocks will have a size of 12 not 10. That means
the 17th block will extend up to offset 204, 18th block up to 216, 19th
block to 228, and 20th block to 240. So 4 out of the 20 blocks are
overflowing the static pool area and 3 of them are even located
completely outside of it.
In this example, we have only 20 blocks that can't be split so there is
no extra free block bitmap allocation beyond the bitmap embedded in the
sys_mem_pool_lvl structure. This means that memory corruption will
happen in whatever data is located alongside the _mpool_buf_##name
array. But even with, say, 40 blocks, or larger blocks, the extra bitmap
size would be small compared to the extent of the overflow, and it would
get corrupted too of course.
And the data corruption will happen even without allocating any memory
since z_sys_mem_pool_base_init() stores free_list pointer nodes into
those blocks, which in turn may get corrupted if that other data is
later modified instead.
Fixing this issue is simple: rounding on the static pool allocation is
"misparenthesized". Let's turn
_ALIGN4(maxsz * nmax)
into
_ALIGN4(maxsz) * nmax
But that's not sufficient.
In z_sys_mem_pool_base_init() we have:
size_t buflen = p->n_max * p->max_sz, sz = p->max_sz;
u32_t *bits = (u32_t *)((u8_t *)p->buf + buflen);
Considering the same parameters as above, here we're locating the extra
free block bitmap at offset `buflen` which is 20 * 10 = 200, again below
the reach of the last 4 memory blocks. If the number of blocks gets past
the size of the embedded bitmap, it will overlap memory blocks.
Also, the block_ptr() call used here to initialize the free block linked
list uses unrounded p->max_sz, meaning that it is initially not locating
dlist nodes within the same block boundaries as what is expected from
z_sys_mem_pool_block_alloc(). This opens the possibility for allocated
adjacent blocks to overwrite dlist nodes, leading to random crashes in
the future.
So a complete fix must round up p->max_sz here too.
Given that runtime usage of max_sz should always be rounded up, it is
then preferable to round it up once at compile time instead and avoid
further mistakes of that sort. The existing _ALIGN4() usage on p->max_sz
at run time are then redundant.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Permission management no longer necessary, the former
parameter for the mutex is now simply ignored.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Update reserved function names starting with one underscore, replacing
them as follows:
'_k_' with 'z_'
'_K_' with 'Z_'
'_handler_' with 'z_handl_'
'_Cstart' with 'z_cstart'
'_Swap' with 'z_swap'
This renaming is done on both global and those static function names
in kernel/include and include/. Other static function names in kernel/
are renamed by removing the leading underscore. Other function names
not starting with any prefix listed above are renamed starting with
a 'z_' or 'Z_' prefix.
Function names starting with two or three leading underscores are not
automatcally renamed since these names will collide with the variants
with two or three leading underscores.
Various generator scripts have also been updated as well as perf,
linker and usb files. These are
drivers/serial/uart_handlers.c
include/linker/kobject-text.ld
kernel/include/syscall_handler.h
scripts/gen_kobject_list.py
scripts/gen_syscall_header.py
Signed-off-by: Patrik Flykt <patrik.flykt@intel.com>
Any word started with underscore followed by and uppercase letter or a
second underscore is a reserved word according with C99.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
SYS_MEM_POOL_KERNEL and SYS_MEM_POOL_USER are used by k_mem_pool flags
and should be defined as a bit mask.
It was defined as zero failing in all places checking for this
bit. e.g pool_irq_lock and pool_irq_unlock were not working correctly
because the check for this flag was always returning false.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
We would like to offer the capability to have memory pool heap data
structures that are usable from user mode threads. The current
k_mem_pool implementation uses IRQ locking and system-wide membership
lists that make it incompatible with user mode constraints.
However, much of the existing memory pool code can be abstracted to some
common functions that are used by both k_mem_pool and the new
sys_mem_pool implementations.
The sys_mem_pool implementation has the following differences:
* The alloc/free APIs work directly with pointers, no internal memory
block structures are exposed to the end user. A pointer to the source
pool is provided for allocation, but freeing memory just requires the
pointer and nothing else.
* k_mem_pool uses IRQ locks and required very fine-grained locking in
order to not affect system latency. sys_mem_pools just use a semaphore
to protect the pool data structures at the API level, since there aren't
implications for system responsiveness with this kind of concurrency
control.
* sys_mem_pools do not support the notion of timeouts for requesting
memory.
* sys_mem_pools are specified at compile time with macros, just like
kernel memory pools. Alternative forms of specification at runtime
will be a later enhancement.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
