Commit 40016a6a92 ("libc/minimal: Use a sys_heap for the malloc
implementation") replaced sys_mem_pool_alloc() with sys_heap_alloc().
The problem is that those aren't equivalent. While the former did
guard against concurrent usage, the later doesn't.
Add the same locking around sys_heap_alloc() that used to be implicit
with sys_mem_pool_alloc().
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
The definition for realloc() says that it should return a pointer
to the allocated memory which is suitably aligned for any built-in
type.
Turn sys_heap_realloc() into a sys_heap_aligned_realloc() and use it
with __alignof__(z_max_align_t) to implement realloc() with proper
memory alignment for any platform.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
The definition for malloc() says that it should return a pointer
to the allocated memory which is suitably aligned for any built-in
type. This requirement was lost in commit 0c15627cc1 ("lib: Remove
sys_mem_pool implementation") where the entire memory pool used to
have an explicit alignment of 16.
Fix this by allocating memory with sys_heap_aligned_alloc() using
__alignof__(z_max_align_t) which will automatically get the needed
alignment on each platform.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
reallocarray() is defined in terms of realloc(). From OpenBSD manual
pages:
"Designed for safe allocation of arrays, the reallocarray()
function is similar to realloc() except it operates on nmemb
members of size size and checks for integer overflow in the
calculation nmemb * size."
The return value of sys_heap_realloc() is not compatible with that
of realloc().
Signed-off-by: Martin Åberg <martin.aberg@gaisler.com>
Most of kernel files where declaring os module without providing
log level. Because of that default log level was used instead of
CONFIG_KERNEL_LOG_LEVEL.
Signed-off-by: Krzysztof Chruscinski <krzysztof.chruscinski@nordicsemi.no>
Now that device_api attribute is unmodified at runtime, as well as all
the other attributes, it is possible to switch all device driver
instance to be constant.
A coccinelle rule is used for this:
@r_const_dev_1
disable optional_qualifier
@
@@
-struct device *
+const struct device *
@r_const_dev_2
disable optional_qualifier
@
@@
-struct device * const
+const struct device *
Fixes#27399
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
Previously, if the arena size was zero, malloc would always fail.
However, the log message was only visible if debug messages were
enabled. Logging an error will hopefully make it more obvious that
CONFIG_MINIMAL_LIBC_MALLOC_ARENA_SIZE should be >= if the minimal
libc and malloc are both used.
Fixes#26720
Signed-off-by: Christopher Friedt <chrisfriedt@gmail.com>
Severely memory constrained systems with known allocation patterns can
benefit from providing their own implementation of malloc with
specifically tuned bucket sizes. Provide a switch to allow users to
replace the default malloc implementation with their own.
Signed-off-by: Josh Gao <josh@jmgao.dev>
The realloc function was a bit too intimate with the mempool accounting.
Abstract that knowledge away and move it where it belongs.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
The mempool allocator implementation recursively breaks a memory block
into 4 sub-blocks until it minimally fits the requested memory size.
The size of each sub-blocks is rounded up to the next word boundary to
preserve word alignment on the returned memory, and this is a problem.
Let's consider max_sz = 2072 and n_max = 1. That's our level 0.
At level 1, we get one level-0 block split in 4 sub-blocks whose size
is WB_UP(2072 / 4) = 520. However 4 * 520 = 2080 so we must discard the
4th sub-block since it doesn't fit inside our 2072-byte parent block.
We're down to 3 * 520 = 1560 bytes of usable memory.
Our memory usage efficiency is now 1560 / 2072 = 75%.
At level 2, we get 3 level-1 blocks, and each of them may be split
in 4 sub-blocks whose size is WB_UP(520 / 4) = 132. But 4 * 132 = 528
so the 4th sub-block has to be discarded again.
We're down to 9 * 132 = 1188 bytes of usable memory.
Our memory usage efficiency is now 1188 / 2072 = 57%.
At level 3, we get 9 level-2 blocks, each split into WB_UP(132 / 4)
= 36 bytes. Again 4 * 36 = 144 so the 4th sub-block is discarded.
We're down to 27 * 36 = 972 bytes of usable memory.
Our memory usage efficiency is now 972 / 2072 = 47%.
What should be done instead, is to round _down_ sub-block sizes
not _up_. This way, sub-blocks still align to word boundaries, and
they always fit within their parent block as the total size may
no longer exceed the initial size.
Using the same max_sz = 2072 would yield a memory usage efficiency of
99% at level 3, so let's demo a worst case 2044 instead.
Level 1: 4 sub-blocks of WB_DN(2044 / 4) = 508 bytes.
We're down to 4 * 508 = 2032 bytes of usable memory.
Our memory usage efficiency is now 2032 / 2044 = 99%.
Level 2: 4 * 4 sub-blocks of WB_DN(508 / 4) = 124 bytes.
We're down to 16 * 124 = 1984 bytes of usable memory.
Our memory usage efficiency is now 1984 / 2044 = 97%.
Level 3: 16 * 4 sub-blocks of WB_DN(124 / 4) = 28 bytes.
We're down to 64 * 28 = 1792 bytes of usable memory.
Our memory usage efficiency is now 1792 / 2044 = 88%.
Conclusion: if max_sz is a power of 2 then we get 100% efficiency at
all levens in both cases. But if not, then the rounding-up method has
a far worse degradation curve than the rounding-down method, wasting
more than 50% of memory in some cases.
So let's round sub-block sizes down rather than up, and remove
block_fits() which purpose was to identify sub-blocks that didn't
fit within their parent block and is now useless.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Since commit 39cd2ebef7 ("malloc: make sure returned memory is
properly aligned") the size of struct sys_mem_pool_block size is
rounded up to the next word boundary.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Minimum alignment and rounding must be done on a word boundary. Let's
replace _ALIGN4() with WB_UP() which is equivalent on 32-bit targets,
and 64-bit aware.
Also enforce a minimal alignment on the memory pool. This is making
a difference mostly on64-bit targets where the widely used 4-byte
alignment is not sufficient.
The _ALIGN4() macro has no users left so it is removed.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
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/math_extras.h to sys/math_extras.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>
Use the new math_extras functions instead of calling builtins directly.
Change a few local variables to size_t after checking that all uses of
the variable actually expects a size_t.
Signed-off-by: Jakob Olesen <jolesen@fb.com>
Excerpt from the manual:
If ptr is NULL, then the call is equivalent to malloc(size) [...]
Without this commit, such calls end with a BUS FAULT.
Signed-off-by: Tomasz Gorochowik <tgorochowik@antmicro.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>
We used to leave byte-long placeholder symbols to ensure
that empty application memory sections did not cause
build errors that were very difficult to understand.
Now we use some relatively portable inline assembly to
generate a symbol, but don't take up any extra space.
The malloc and libc partitions are now only instantiated
if there is some data to put in them.
Fixes: #13923
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This is an integral part of userspace and cannot be used
on its own. Fold into the main userspace configuration.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
* Newlib now defines a special z_newlib_partition containing
all globals relevant to newlib. Most of these are in libc.a
with a heap tracking variable in newlib's hooks.
* Both C libraries now expose a k_mem_partition containing the
bounds of the malloc heap arena. Threads that want to use
libc malloc() will need to add this to their memory domain.
* z_newlib_get_heap_bounds has been removed, in favor of the
memory partition for the heap arena
* ztest now includes the C library partitions in its memory
domain.
* The mem_alloc test now runs in user mode to prove that this
all works for both C libraries.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Make if statement using pointers explicitly check whether the value is
NULL or not.
The C standard does not say that the null pointer is the same as the
pointer to memory address 0 and because of this is a good practice
always compare with the macro NULL.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
The return of memset is never checked. This patch explicitly ignore
the return to avoid MISRA-C violations.
The only directory excluded directory was ext/* since it contains
only imported code.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
