zephyr/kernel/errno.c

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/*
* Copyright (c) 2015 Wind River Systems, Inc.
*
* SPDX-License-Identifier: Apache-2.0
*/
/** @file
*
* @brief Per-thread errno accessor function
*
* Allow accessing the errno for the current thread without involving the
* context switching.
*/
headers: Refactor kernel and arch headers. This commit refactors kernel and arch headers to establish a boundary between private and public interface headers. The refactoring strategy used in this commit is detailed in the issue This commit introduces the following major changes: 1. Establish a clear boundary between private and public headers by removing "kernel/include" and "arch/*/include" from the global include paths. Ideally, only kernel/ and arch/*/ source files should reference the headers in these directories. If these headers must be used by a component, these include paths shall be manually added to the CMakeLists.txt file of the component. This is intended to discourage applications from including private kernel and arch headers either knowingly and unknowingly. - kernel/include/ (PRIVATE) This directory contains the private headers that provide private kernel definitions which should not be visible outside the kernel and arch source code. All public kernel definitions must be added to an appropriate header located under include/. - arch/*/include/ (PRIVATE) This directory contains the private headers that provide private architecture-specific definitions which should not be visible outside the arch and kernel source code. All public architecture- specific definitions must be added to an appropriate header located under include/arch/*/. - include/ AND include/sys/ (PUBLIC) This directory contains the public headers that provide public kernel definitions which can be referenced by both kernel and application code. - include/arch/*/ (PUBLIC) This directory contains the public headers that provide public architecture-specific definitions which can be referenced by both kernel and application code. 2. Split arch_interface.h into "kernel-to-arch interface" and "public arch interface" divisions. - kernel/include/kernel_arch_interface.h * provides private "kernel-to-arch interface" definition. * includes arch/*/include/kernel_arch_func.h to ensure that the interface function implementations are always available. * includes sys/arch_interface.h so that public arch interface definitions are automatically included when including this file. - arch/*/include/kernel_arch_func.h * provides architecture-specific "kernel-to-arch interface" implementation. * only the functions that will be used in kernel and arch source files are defined here. - include/sys/arch_interface.h * provides "public arch interface" definition. * includes include/arch/arch_inlines.h to ensure that the architecture-specific public inline interface function implementations are always available. - include/arch/arch_inlines.h * includes architecture-specific arch_inlines.h in include/arch/*/arch_inline.h. - include/arch/*/arch_inline.h * provides architecture-specific "public arch interface" inline function implementation. * supersedes include/sys/arch_inline.h. 3. Refactor kernel and the existing architecture implementations. - Remove circular dependency of kernel and arch headers. The following general rules should be observed: * Never include any private headers from public headers * Never include kernel_internal.h in kernel_arch_data.h * Always include kernel_arch_data.h from kernel_arch_func.h * Never include kernel.h from kernel_struct.h either directly or indirectly. Only add the kernel structures that must be referenced from public arch headers in this file. - Relocate syscall_handler.h to include/ so it can be used in the public code. This is necessary because many user-mode public codes reference the functions defined in this header. - Relocate kernel_arch_thread.h to include/arch/*/thread.h. This is necessary to provide architecture-specific thread definition for 'struct k_thread' in kernel.h. - Remove any private header dependencies from public headers using the following methods: * If dependency is not required, simply omit * If dependency is required, - Relocate a portion of the required dependencies from the private header to an appropriate public header OR - Relocate the required private header to make it public. This commit supersedes #20047, addresses #19666, and fixes #3056. Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
2019-10-24 17:08:21 +02:00
#include <kernel.h>
#include <syscall_handler.h>
unified: initial unified kernel implementation Summary of what this includes: initialization: Copy from nano_init.c, with the following changes: - the main thread is the continuation of the init thread, but an idle thread is created as well - _main() initializes threads in groups and starts the EXE group - the ready queues are initialized - the main thread is marked as non-essential once the system init is done - a weak main() symbol is provided if the application does not provide a main() function scheduler: Not an exhaustive list, but basically provide primitives for: - adding/removing a thread to/from a wait queue - adding/removing a thread to/from the ready queue - marking thread as ready - locking/unlocking the scheduler - instead of locking interrupts - getting/setting thread priority - checking what state (coop/preempt) a thread is currenlty running in - rescheduling threads - finding what thread is the next to run - yielding/sleeping/aborting sleep - finding the current thread threads: - Add operationns on threads, such as creating and starting them. standardized handling of kernel object return codes: - Kernel objects now cause _Swap() to return the following values: 0 => operation successful -EAGAIN => operation timed out -Exxxxx => operation failed for another reason - The thread's swap_data field can be used to return any additional information required to complete the operation, such as the actual result of a successful operation. timeouts: - same as nano timeouts, renamed to simply 'timeouts' - the kernel is still tick-based, but objects take timeout values in ms for forward compatibility with a tickless kernel. semaphores: - Port of the nanokernel semaphores, which have the same basic behaviour as the microkernel ones. Semaphore groups are not yet implemented. - These semaphores are enhanced in that they accept an initial count and a count limit. This allows configuring them as binary semaphores, and also provisioning them without having to "give" the semaphore multiple times before using them. mutexes: - Straight port of the microkernel mutexes. An init function is added to allow defining them at runtime. pipes: - straight port timers: - amalgamation of nano and micro timers, with all functionalities intact. events: - re-implementation, using semaphores and workqueues. mailboxes: - straight port message queues: - straight port of microkernel FIFOs memory maps: - straight port workqueues: - Basically, have all APIs follow the k_ naming rule, and use the _timeout subsystem from the unified kernel directory, and not the _nano_timeout one. stacks: - Port of the nanokernel stacks. They can now have multiple threads pending on them and threads can wait with a timeout. LIFOs: - Straight port of the nanokernel LIFOs. FIFOs: - Straight port of the nanokernel FIFOs. Work by: Dmitriy Korovkin <dmitriy.korovkin@windriver.com> Peter Mitsis <peter.mitsis@windriver.com> Allan Stephens <allan.stephens@windriver.com> Benjamin Walsh <benjamin.walsh@windriver.com> Change-Id: Id3cadb3694484ab2ca467889cfb029be3cd3a7d6 Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
2016-09-03 00:55:39 +02:00
/*
* Define _k_neg_eagain for use in assembly files as errno.h is
* not assembly language safe.
* FIXME: wastes 4 bytes
unified: initial unified kernel implementation Summary of what this includes: initialization: Copy from nano_init.c, with the following changes: - the main thread is the continuation of the init thread, but an idle thread is created as well - _main() initializes threads in groups and starts the EXE group - the ready queues are initialized - the main thread is marked as non-essential once the system init is done - a weak main() symbol is provided if the application does not provide a main() function scheduler: Not an exhaustive list, but basically provide primitives for: - adding/removing a thread to/from a wait queue - adding/removing a thread to/from the ready queue - marking thread as ready - locking/unlocking the scheduler - instead of locking interrupts - getting/setting thread priority - checking what state (coop/preempt) a thread is currenlty running in - rescheduling threads - finding what thread is the next to run - yielding/sleeping/aborting sleep - finding the current thread threads: - Add operationns on threads, such as creating and starting them. standardized handling of kernel object return codes: - Kernel objects now cause _Swap() to return the following values: 0 => operation successful -EAGAIN => operation timed out -Exxxxx => operation failed for another reason - The thread's swap_data field can be used to return any additional information required to complete the operation, such as the actual result of a successful operation. timeouts: - same as nano timeouts, renamed to simply 'timeouts' - the kernel is still tick-based, but objects take timeout values in ms for forward compatibility with a tickless kernel. semaphores: - Port of the nanokernel semaphores, which have the same basic behaviour as the microkernel ones. Semaphore groups are not yet implemented. - These semaphores are enhanced in that they accept an initial count and a count limit. This allows configuring them as binary semaphores, and also provisioning them without having to "give" the semaphore multiple times before using them. mutexes: - Straight port of the microkernel mutexes. An init function is added to allow defining them at runtime. pipes: - straight port timers: - amalgamation of nano and micro timers, with all functionalities intact. events: - re-implementation, using semaphores and workqueues. mailboxes: - straight port message queues: - straight port of microkernel FIFOs memory maps: - straight port workqueues: - Basically, have all APIs follow the k_ naming rule, and use the _timeout subsystem from the unified kernel directory, and not the _nano_timeout one. stacks: - Port of the nanokernel stacks. They can now have multiple threads pending on them and threads can wait with a timeout. LIFOs: - Straight port of the nanokernel LIFOs. FIFOs: - Straight port of the nanokernel FIFOs. Work by: Dmitriy Korovkin <dmitriy.korovkin@windriver.com> Peter Mitsis <peter.mitsis@windriver.com> Allan Stephens <allan.stephens@windriver.com> Benjamin Walsh <benjamin.walsh@windriver.com> Change-Id: Id3cadb3694484ab2ca467889cfb029be3cd3a7d6 Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
2016-09-03 00:55:39 +02:00
*/
const int _k_neg_eagain = -EAGAIN;
#ifdef CONFIG_ERRNO
#ifdef CONFIG_USERSPACE
int *z_impl_z_errno(void)
{
/* Initialized to the lowest address in the stack so the thread can
* directly read/write it
*/
return &_current->userspace_local_data->errno_var;
}
userspace: Support for split 64 bit arguments System call arguments, at the arch layer, are single words. So passing wider values requires splitting them into two registers at call time. This gets even more complicated for values (e.g k_timeout_t) that may have different sizes depending on configuration. This patch adds a feature to gen_syscalls.py to detect functions with wide arguments and automatically generates code to split/unsplit them. Unfortunately the current scheme of Z_SYSCALL_DECLARE_* macros won't work with functions like this, because for N arguments (our current maximum N is 10) there are 2^N possible configurations of argument widths. So this generates the complete functions for each handler and wrapper, effectively doing in python what was originally done in the preprocessor. Another complexity is that traditional the z_hdlr_*() function for a system call has taken the raw list of word arguments, which does not work when some of those arguments must be 64 bit types. So instead of using a single Z_SYSCALL_HANDLER macro, this splits the job of z_hdlr_*() into two steps: An automatically-generated unmarshalling function, z_mrsh_*(), which then calls a user-supplied verification function z_vrfy_*(). The verification function is typesafe, and is a simple C function with exactly the same argument and return signature as the syscall impl function. It is also not responsible for validating the pointers to the extra parameter array or a wide return value, that code gets automatically generated. This commit includes new vrfy/msrh handling for all syscalls invoked during CI runs. Future commits will port the less testable code. Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2019-08-06 22:34:31 +02:00
static inline int *z_vrfy_z_errno(void)
{
return z_impl_z_errno();
}
#include <syscalls/z_errno_mrsh.c>
#else
int *z_impl_z_errno(void)
{
kernel/arch: consolidate tTCS and TNANO definitions There was a lot of duplication between architectures for the definition of threads and the "nanokernel" guts. These have been consolidated. Now, a common file kernel/unified/include/kernel_structs.h holds the common definitions. Architectures provide two files to complement it: kernel_arch_data.h and kernel_arch_func.h. The first one contains at least the struct _thread_arch and struct _kernel_arch data structures, as well as the struct _callee_saved and struct _caller_saved register layouts. The second file contains anything that needs what is provided by the common stuff in kernel_structs.h. Those two files are only meant to be included in kernel_structs.h in very specific locations. The thread data structure has been separated into three major parts: common struct _thread_base and struct k_thread, and arch-specific struct _thread_arch. The first and third ones are included in the second. The struct s_NANO data structure has been split into two: common struct _kernel and arch-specific struct _kernel_arch. The latter is included in the former. Offsets files have also changed: nano_offsets.h has been renamed kernel_offsets.h and is still included by the arch-specific offsets.c. Also, since the thread and kernel data structures are now made of sub-structures, offsets have to be added to make up the full offset. Some of these additions have been consolidated in shorter symbols, available from kernel/unified/include/offsets_short.h, which includes an arch-specific offsets_arch_short.h. Most of the code include offsets_short.h now instead of offsets.h. Change-Id: I084645cb7e6db8db69aeaaf162963fe157045d5a Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
2016-11-08 16:36:50 +01:00
return &_current->errno_var;
}
#endif /* CONFIG_USERSPACE */
#endif /* CONFIG_ERRNO */