Extend capabilities of a minimal libc to support C11 capability
to allocate memory with requested alignment.
Signed-off-by: Piotr Pryga <piotr.pryga@nordicsemi.no>
As of today <zephyr/zephyr.h> is 100% equivalent to <zephyr/kernel.h>.
This patch proposes to then include <zephyr/kernel.h> instead of
<zephyr/zephyr.h> since it is more clear that you are including the
Kernel APIs and (probably) nothing else. <zephyr/zephyr.h> sounds like a
catch-all header that may be confusing. Most applications need to
include a bunch of other things to compile, e.g. driver headers or
subsystem headers like BT, logging, etc.
The idea of a catch-all header in Zephyr is probably not feasible
anyway. Reason is that Zephyr is not a library, like it could be for
example `libpython`. Zephyr provides many utilities nowadays: a kernel,
drivers, subsystems, etc and things will likely grow. A catch-all header
would be massive, difficult to keep up-to-date. It is also likely that
an application will only build a small subset. Note that subsystem-level
headers may use a catch-all approach to make things easier, though.
NOTE: This patch is **NOT** removing the header, just removing its usage
in-tree. I'd advocate for its deprecation (add a #warning on it), but I
understand many people will have concerns.
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
This commit changes the invocation of the minimal libc malloc
initialisation function such that it is executed during the POST_KERNEL
phase instead of the APPLICATION phase.
This is necessary in order to ensure that the application
initialisation functions (i.e. the functions called during the
APPLICATIION phase) can make use of the libc heap.
Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
MISRA C:2012 Rule 21.13 (Any value passed to a function in <ctype.h>
shall be representable as an unsigned char or be the value EOF).
Functions in <ctype.h> have undefined behavior if they are called with
any other value. Callers affected by this change are not prepared to
handle EOF anyway. The addition of these casts avoids the issue
and does not result in any performance penalty.
Signed-off-by: Abramo Bagnara <abramo.bagnara@bugseng.com>
Signed-off-by: Simon Hein <SHein@baumer.com>
This commit globally defines the `Z_LIBC_DATA` macro, which is used to
place variables into the libc memory partition, so that it can be
re-used.
Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
This commit introduces a new configuration called
`CONFIG_MINIMAL_LIBC_NON_REENTRANT_FUNCTIONS`, which enables the
traditional non-reentrant (i.e. not thread-safe) version of the C
standard library functions such as rand() and gmtime() when the
respective configs are enabled.
The non-reentrant functions make use of the globals and require an
additional memory partition (MPU region), which is scarce on low-end
devices, when CONFIG_USERSPACE=y.
The purpose of this option is to classify the MPU resource intensive
functions as a separate category and only enable them when there is a
demand for such.
Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
This commit adds the `rand_r` function, which is a reentrant (i.e.
thread-safe) version of the `rand` function, such that a thread-safe
variant is always available.
Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
This commit adds the strtoull function implementation that is licensed
BSD-3-Clause, which is an OSI-approved license, with the modifications
necessary for adoption into the Zephyr minimal C library.
Origin: Newlib
License: BSD 3-Clause
URL: git://sourceware.org/git/newlib-cygwin.git
Commit: 9042d0ce65533a26fc3264206db5828d5692332c
Purpose: strtoull function support in the minimal C library
Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
This commit removes the strtoull function implementation that is
licensed BSD-4-Clause-UC, which is not an OSI-approved license.
Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
This commit adds the strtoll function implementation that is licensed
BSD-3-Clause, which is an OSI-approved license, with the modifications
necessary for adoption into the Zephyr minimal C library.
Origin: Newlib
License: BSD 3-Clause
URL: git://sourceware.org/git/newlib-cygwin.git
Commit: 9042d0ce65533a26fc3264206db5828d5692332c
Purpose: strtoll function support in the minimal C library
Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
This commit removes the strtoll function implementation that is
licensed BSD-4-Clause-UC, which is not an OSI-approved license.
Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
This commit adds the strtoul function implementation that is licensed
BSD-3-Clause, which is an OSI-approved license, with the modifications
necessary for adoption into the Zephyr minimal C library.
Origin: Newlib
License: BSD 3-Clause
URL: git://sourceware.org/git/newlib-cygwin.git
Commit: 9042d0ce65533a26fc3264206db5828d5692332c
Purpose: strtoul function support in the minimal C library
Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
This commit removes the strtoul function implementation that is
licensed BSD-4-Clause-UC, which is not an OSI-approved license.
Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
This commit adds the strtol function implementation that is licensed
BSD-3-Clause, which is an OSI-approved license, with the modifications
necessary for adoption into the Zephyr minimal C library.
Origin: Newlib
License: BSD 3-Clause
URL: git://sourceware.org/git/newlib-cygwin.git
Commit: 9042d0ce65533a26fc3264206db5828d5692332c
Purpose: strtol function support in the minimal C library
Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
This commit removes the strtol function implementation that is
licensed BSD-4-Clause-UC, which is not an OSI-approved license.
Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
In order to bring consistency in-tree, migrate all lib code to the new
prefix <zephyr/...>. Note that the conversion has been scripted, refer
to zephyrproject-rtos#45388 for more details.
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
- strtoll() and strtoull() are copies of strtol() and strtoul() with
types changed to long long instead of long.
- added tests
- added documentation
- removed stubs from civetweb sample
Signed-off-by: Gerhard Jörges <joerges@metratec.com>
Remove the cast of the two parameter compare function used by qsort, to
the three parameter callback function used by qsort_r, in order to
ensure compatibility with other toolchains, even those off-tree.
Fixes#42870
Signed-off-by: Danny Oerndrup <daor@demant.com>
This change implements qsort() for the minimal libc via Heapsort.
Heapsort time complexity is O(n log(n)) in the best, average,
and worst cases. It is O(1) in space complexity (i.e. sorts
in-place) and is iterative rather than recursive. Heapsort is
not stable (i.e. does not preserve order of identical elements).
On cortex-m0, this implementation occupies ~240 bytes.
Fixes#28896
Signed-off-by: Christopher Friedt <chrisfriedt@gmail.com>
When CONFIG_USERSPACE is turned off, the POOL_SECTION will be located in
.data section. This will increase the target binary size. Since the
memory pool is for malloc() use and it doesn't need for initial values,
locate it in the .bss section to reduce binary size.
Signed-off-by: Dylan Hung <dylan_hung@aspeedtech.com>
Change-Id: Iee52ac06a48414c083518c79775fe31334eab674
rand() and srand() are pseudo-random number generator functions
defined in ISO C. This implementation uses the Linear Congruential
Generator (LCG) algorithm with the following parameters, which are the
same as used in GNU Libc "TYPE_0" algorithm.
Modulus 2^31
Multiplier 1103515245
Increment 12345
Output Bits 30..0
Note that the default algorithm used by GNU Libc is not TYPE_0, and
TYPE_0 should be selected first by an initstate() call as shown below.
All global variables in a C library must be routed to a memory
partition in order to be used by user-mode applications when
CONFIG_USERSPACE is enabled. Thus, srand_seed is marked as
such. z_libc_partition is originally used by the Newlib C library but
it's generic enough to be used by either the minimal libc or the
newlib.
All other functions in the Minimal C library, however, don't require
global variables/states. Unconditionally using z_libc_partition with
the minimal libc might be a problem for applications utilizing many
custom memory partitions on platforms with a limited number of MPU
regions (eg. Cortex M0/M3). This commit introduces a kconfig option
CONFIG_MINIMAL_LIBC_RAND so that applications can enable the
functions if needed. The option is disabled by default.
Because this commit _does_ implement rand() and srand(), our coding
guideline check on GitHub Action finds it as a violation.
Error: lib/libc/minimal/include/stdlib.h:45:WARNING: Violation to
rule 21.2 (Should not used a reserved identifier) - srand
But this is false positive.
The following is a simple test program for LCG with GNU Libc.
#include <stdio.h>
#include <stdlib.h>
int main()
{
static char state[8];
/* Switch GLIBC to use LCG/TYPE_0 generator type. */
initstate(0, state, sizeof(state));
srand(1); /* Or any other value. */
printf("%d\n", rand());
printf("%d\n", rand());
return 0;
}
See initstate(3p) for more detail about how to use LCG in GLIBC.
Signed-off-by: Yasushi SHOJI <yashi@spacecubics.com>
According to the Zephyr Coding Guideline all switch statements
shall be well-formed.
Added a default labels to switch-clauses without them.
Added comments to the empty default cases.
Found as a coding guideline violation (MISRA R16.1) by static
coding scanning tool.
Signed-off-by: Maksim Masalski <maksim.masalski@intel.com>
- When malloc() is called with a size of 0 we should not set errno
to ENOMEM as there is no actual allocation failure in that case.
This duplicates the realloc() behavior.
- Put unlock_ret assignments on separate lines, otherwise gcc complains
about unused variables when the tests on it are disabled.
- There NULL return added in 952970d6cb are completely pointless.
First, there is no reason for sys_mutex_unlock() to fail, and even
if it did, those returns would be blatent memory leaks. Remove them.
No one should blindly modify code just to make static code
analysers happy.
- Replace all CHECKIF() by explicit assertion statements to uniformize
those checks and drop the NULL returns entirely. We can't return
anything in the free() case, and there are no runtime conditions
for sys_mutex_lock() to sometimes succeed and sometimes fail anyway.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
The identifiers used in the declaration and definition of a function
shall be identical [MISRAC2012-RULE_8_3-b]
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
Fix#32938 [Coverity CID :219508] "Unchecked return value in
lib/libc/minimal/source/stdlib/malloc.c"
The Coverity complains about sys_mutex_lock() which returns 0 if
locked. I added also the same check on returned value for
sys_mutex_unlock() which returns 0 if unlocked.
Signed-off-by: Guðni Már Gilbert <gudni.m.g@gmail.com>
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>
abort() is an important runtime function, oftentimes used to signal
abnormal execution conditions in generic applications. Worse, they
may be used under such circumstances in e.g. compiler support
libraries, in which case lack of implementation of this function
will lead to link error.
Fixes: #29541
Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
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>
Per guidelines, all statements should have braces around them. We do not
have a CI check for this, so a few went in unnoticed.
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>
