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.
*/
#include <zephyr/kernel.h>
#include <zephyr/internal/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>
2016-09-02 18:55:39 -04:00
/*
* 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>
2016-09-02 18:55:39 -04:00
*/
const int _k_neg_eagain = -EAGAIN;
#ifdef CONFIG_ERRNO
#if defined(CONFIG_LIBC_ERRNO)
/* nothing needed here */
#elif defined(CONFIG_ERRNO_IN_TLS)
Z_THREAD_LOCAL int z_errno_var;
#else
#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 13:34:31 -07:00
static inline int *z_vrfy_z_errno(void)
{
return z_impl_z_errno();
}
#include <zephyr/syscalls/z_errno_mrsh.c>
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 13:34:31 -07:00
#else
int *z_impl_z_errno(void)
{
return &_current->errno_var;
}
#endif /* CONFIG_USERSPACE */
#endif /* CONFIG_ERRNO_IN_TLS */
#endif /* CONFIG_ERRNO */