incubator-nuttx/include/nuttx/lib/modlib.h

559 lines
19 KiB
C

/****************************************************************************
* include/nuttx/lib/modlib.h
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
#ifndef __INCLUDE_NUTTX_LIB_MODLIB_H
#define __INCLUDE_NUTTX_LIB_MODLIB_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <elf.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Configuration ************************************************************/
#ifndef CONFIG_MODLIB_MAXDEPEND
# define CONFIG_MODLIB_MAXDEPEND 0
#endif
#ifndef CONFIG_MODLIB_ALIGN_LOG2
# define CONFIG_MODLIB_ALIGN_LOG2 2
#endif
#ifndef CONFIG_MODLIB_BUFFERSIZE
# define CONFIG_MODLIB_BUFFERSIZE 32
#endif
#ifndef CONFIG_MODLIB_BUFFERINCR
# define CONFIG_MODLIB_BUFFERINCR 32
#endif
/* CONFIG_DEBUG_INFO, and CONFIG_LIBC_MODLIB have to be defined or
* CONFIG_MODLIB_DUMPBUFFER does nothing.
*/
#if !defined(CONFIG_DEBUG_INFO) || !defined(CONFIG_LIBC_MODLIB)
# undef CONFIG_MODLIB_DUMPBUFFER
#endif
#ifdef CONFIG_MODLIB_DUMPBUFFER
# define modlib_dumpbuffer(m,b,n) sinfodumpbuffer(m,b,n)
#else
# define modlib_dumpbuffer(m,b,n)
#endif
/* Module names. These are only used by the kernel module and will be
* disabled in all other configurations.
*
* FLAT build: There are only kernel modules and kernel modules
* masquerading as shared libraries. Names are required.
* PROTECTED and KERNEL builds: Names are only needed in the kernel
* portion of the build
*/
#if defined(CONFIG_BUILD_FLAT) || defined(__KERNEL__)
# define HAVE_MODLIB_NAMES
# define MODLIB_NAMEMAX NAME_MAX
#endif
/****************************************************************************
* Public Types
****************************************************************************/
/* This is the type of the function that is called to uninitialize the
* the loaded module. This may mean, for example, un-registering a device
* driver. If the module is successfully uninitialized, its memory will be
* deallocated.
*
* Input Parameters:
* arg - An opaque argument that was previously returned by the initializer
* function.
*
* Returned Value:
* Zero (OK) on success; a negated errno value on any failure to
* uninitialize the module. If zero is returned, then the module memory
* will be deallocated. If the module is still in use (for example with
* open driver instances), the uninitialization function should fail with
* -EBUSY
*/
typedef CODE int (*mod_uninitializer_t)(FAR void *arg);
/* The content of this structure is filled by module_initialize().
*
* uninitializer - The pointer to the uninitialization function. NULL may
* be specified if no uninitialization is needed (i.e, the
* the module memory can be deallocated at any time).
* arg - An argument that will be passed to the uninitialization
* function.
* exports - A symbol table exported by the module
* nexports - The number of symbols in the exported symbol table.
*/
struct symtab_s;
struct mod_info_s
{
mod_uninitializer_t uninitializer; /* Module uninitializer */
FAR void *arg; /* Uninitializer argument */
FAR const struct symtab_s *exports; /* Symbols exported by module */
unsigned int nexports; /* Number of symbols in exports list */
};
/* A NuttX module is expected to export a function called module_initialize()
* that has the following function prototype. This function should appear as
* the entry point in the ELF module file and will be called by the loader
* logic after the module has been loaded into memory.
*
* Input Parameters:
* modinfo - Module information to be filled by the initializer.
*
* Returned Value:
* Zero (OK) on success; a negated errno value on any failure to
* initialize the module.
*/
typedef CODE int (*mod_initializer_t)(FAR struct mod_info_s *modinfo);
/* This is the type of the callback function used by
* modlib_registry_foreach()
*/
struct module_s;
typedef CODE int (*mod_callback_t)(FAR struct module_s *modp, FAR void *arg);
/* This describes the file to be loaded. */
struct module_s
{
FAR struct module_s *flink; /* Supports a singly linked list */
#ifdef HAVE_MODLIB_NAMES
FAR char modname[MODLIB_NAMEMAX]; /* Module name */
#endif
#if defined(CONFIG_FS_PROCFS) && !defined(CONFIG_FS_PROCFS_EXCLUDE_MODULE)
mod_initializer_t initializer; /* Module initializer function */
#endif
struct mod_info_s modinfo; /* Module information */
FAR void *textalloc; /* Allocated kernel text memory */
FAR void *dataalloc; /* Allocated kernel memory */
int dynamic; /* Module is a dynamic shared object */
#if defined(CONFIG_FS_PROCFS) && !defined(CONFIG_FS_PROCFS_EXCLUDE_MODULE)
size_t textsize; /* Size of the kernel .text memory allocation */
size_t datasize; /* Size of the kernel .bss/.data memory allocation */
#endif
#if CONFIG_MODLIB_MAXDEPEND > 0
uint8_t dependents; /* Number of modules that depend on this module */
/* This is an upacked array of pointers to other modules that this module
* depends upon.
*/
FAR struct module_s *dependencies[CONFIG_MODLIB_MAXDEPEND];
#endif
uintptr_t finiarr; /* .fini_array */
uint16_t nfini; /* Number of entries in .fini_array */
};
/* This struct provides a description of the currently loaded instantiation
* of the kernel module.
*/
struct mod_loadinfo_s
{
/* elfalloc is the base address of the memory that is allocated to hold the
* module image.
*
* The alloc[] array in struct module_s will hold memory that persists
* after the module has been loaded.
*/
uintptr_t textalloc; /* .text memory allocated when module was loaded */
uintptr_t datastart; /* Start of.bss/.data memory in .text allocation */
size_t textsize; /* Size of the module .text memory allocation */
size_t datasize; /* Size of the module .bss/.data memory allocation */
size_t textalign; /* Necessary alignment of .text */
size_t dataalign; /* Necessary alignment of .bss/.text */
off_t filelen; /* Length of the entire module file */
Elf_Ehdr ehdr; /* Buffered module file header */
FAR Elf_Phdr *phdr; /* Buffered module program headers */
FAR Elf_Shdr *shdr; /* Buffered module section headers */
FAR void *exported; /* Module exports */
uint8_t *iobuffer; /* File I/O buffer */
uintptr_t datasec; /* ET_DYN - data area start from Phdr */
uintptr_t segpad; /* Padding between text and data */
uintptr_t initarr; /* .init_array */
uintptr_t finiarr; /* .fini_array */
uintptr_t preiarr; /* .preinit_array */
uint16_t ninit; /* Number of .init_array entries */
uint16_t nfini; /* Number of .fini_array entries */
uint16_t nprei; /* Number of .preinit_array entries */
uint16_t symtabidx; /* Symbol table section index */
uint16_t strtabidx; /* String table section index */
uint16_t dsymtabidx; /* Dynamic symbol table section index */
uint16_t buflen; /* size of iobuffer[] */
int filfd; /* Descriptor for the file being loaded */
int nexports; /* ET_DYN - Number of symbols exported */
};
/****************************************************************************
* Public Data
****************************************************************************/
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
/****************************************************************************
* Name: modlib_initialize
*
* Description:
* This function is called to configure the library to process an kernel
* module.
*
* Returned Value:
* 0 (OK) is returned on success and a negated errno is returned on
* failure.
*
****************************************************************************/
int modlib_initialize(FAR const char *filename,
FAR struct mod_loadinfo_s *loadinfo);
/****************************************************************************
* Name: modlib_uninitialize
*
* Description:
* Releases any resources committed by modlib_initialize(). This
* essentially undoes the actions of modlib_initialize.
*
* Returned Value:
* 0 (OK) is returned on success and a negated errno is returned on
* failure.
*
****************************************************************************/
int modlib_uninitialize(FAR struct mod_loadinfo_s *loadinfo);
/****************************************************************************
* Name: modlib_getsymtab
*
* Description:
* Get the current symbol table selection as an atomic operation.
*
* Input Parameters:
* symtab - The location to store the symbol table.
* nsymbols - The location to store the number of symbols in the symbol
* table.
*
* Returned Value:
* None
*
****************************************************************************/
void modlib_getsymtab(FAR const struct symtab_s **symtab, FAR int *nsymbols);
/****************************************************************************
* Name: modlib_setsymtab
*
* Description:
* Select a new symbol table selection as an atomic operation.
*
* Input Parameters:
* symtab - The new symbol table.
* nsymbols - The number of symbols in the symbol table.
*
* Returned Value:
* None
*
****************************************************************************/
void modlib_setsymtab(FAR const struct symtab_s *symtab, int nsymbols);
/****************************************************************************
* Name: modlib_load
*
* Description:
* Loads the binary into memory, allocating memory, performing relocations
* and initializing the data and bss segments.
*
* Returned Value:
* 0 (OK) is returned on success and a negated errno is returned on
* failure.
*
****************************************************************************/
int modlib_load(FAR struct mod_loadinfo_s *loadinfo);
/****************************************************************************
* Name: modlib_bind
*
* Description:
* Bind the imported symbol names in the loaded module described by
* 'loadinfo' using the exported symbol values provided by
* modlib_setsymtab().
*
* Returned Value:
* 0 (OK) is returned on success and a negated errno is returned on
* failure.
*
****************************************************************************/
int modlib_bind(FAR struct module_s *modp,
FAR struct mod_loadinfo_s *loadinfo);
/****************************************************************************
* Name: modlib_unload
*
* Description:
* This function unloads the object from memory. This essentially undoes
* the actions of modlib_load. It is called only under certain error
* conditions after the module has been loaded but not yet started.
*
* Input Parameters:
* modp - Module state information
* loadinfo - Load state information
*
* Returned Value:
* 0 (OK) is returned on success and a negated errno is returned on
* failure.
*
****************************************************************************/
int modlib_unload(struct mod_loadinfo_s *loadinfo);
/****************************************************************************
* Name: modlib_depend
*
* Description:
* Set up module dependencies between the exporter and the importer of a
* symbol. The happens when the module is installed via insmod and a
* symbol is imported from another module.
*
* Returned Value:
* 0 (OK) is returned on success and a negated errno is returned on
* failure.
*
* Assumptions:
* Caller holds the registry lock.
*
****************************************************************************/
#if CONFIG_MODLIB_MAXDEPEND > 0
int modlib_depend(FAR struct module_s *importer,
FAR struct module_s *exporter);
#endif
/****************************************************************************
* Name: modlib_undepend
*
* Description:
* Tear down module dependencies between the exporters and the importer of
* symbols. This happens when the module is removed via rmmod (and on
* error handling cases in insmod).
*
* Returned Value:
* 0 (OK) is returned on success and a negated errno is returned on
* failure.
*
* Assumptions:
* Caller holds the registry lock.
*
****************************************************************************/
#if CONFIG_MODLIB_MAXDEPEND > 0
int modlib_undepend(FAR struct module_s *importer);
#endif
/****************************************************************************
* Name: modlib_read
*
* Description:
* Read 'readsize' bytes from the object file at 'offset'. The data is
* read into 'buffer.'
*
* Returned Value:
* 0 (OK) is returned on success and a negated errno is returned on
* failure.
*
****************************************************************************/
int modlib_read(FAR struct mod_loadinfo_s *loadinfo, FAR uint8_t *buffer,
size_t readsize, off_t offset);
/****************************************************************************
* Name: modlib_registry_lock
*
* Description:
* Get exclusive access to the module registry.
*
* Input Parameters:
* None
*
* Returned Value:
* None
*
****************************************************************************/
void modlib_registry_lock(void);
/****************************************************************************
* Name: modlib_registry_unlock
*
* Description:
* Relinquish the lock on the module registry
*
* Input Parameters:
* None
*
* Returned Value:
* None
*
****************************************************************************/
void modlib_registry_unlock(void);
/****************************************************************************
* Name: modlib_registry_add
*
* Description:
* Add a new entry to the module registry.
*
* Input Parameters:
* modp - The module data structure to be registered.
*
* Returned Value:
* None
*
* Assumptions:
* The caller holds the lock on the module registry.
*
****************************************************************************/
void modlib_registry_add(FAR struct module_s *modp);
/****************************************************************************
* Name: modlib_registry_del
*
* Description:
* Remove a module entry from the registry
*
* Input Parameters:
* modp - The registry entry to be removed.
*
* Returned Value:
* Zero (OK) is returned if the registry entry was deleted. Otherwise,
* a negated errno value is returned.
*
* Assumptions:
* The caller holds the lock on the module registry.
*
****************************************************************************/
int modlib_registry_del(FAR struct module_s *modp);
/****************************************************************************
* Name: modlib_registry_find
*
* Description:
* Find an entry in the module registry using the name of the module.
*
* Input Parameters:
* modname - The name of the module to be found
*
* Returned Value:
* If the registry entry is found, a pointer to the module entry is
* returned. NULL is returned if the entry is not found.
*
* Assumptions:
* The caller holds the lock on the module registry.
*
****************************************************************************/
#ifdef HAVE_MODLIB_NAMES
FAR struct module_s *modlib_registry_find(FAR const char *modname);
#endif
/****************************************************************************
* Name: modlib_registry_verify
*
* Description:
* Verify that a module handle is valid by traversing the module list and
* assuring that the module still resides in the list. If it does not,
* the handle is probably a stale pointer.
*
* Input Parameters:
* modp - The registry entry to be verified.
*
* Returned Value:
* Returns OK is the module is valid; -ENOENT otherwise.
*
* Assumptions:
* The caller holds the lock on the module registry.
*
****************************************************************************/
int modlib_registry_verify(FAR struct module_s *modp);
/****************************************************************************
* Name: modlib_registry_foreach
*
* Description:
* Visit each module in the registry. This is an internal OS interface and
* not available for use by applications.
*
* Input Parameters:
* callback - This callback function was be called for each entry in the
* registry.
* arg - This opaque argument will be passed to the callback function.
*
* Returned Value:
* This function normally returns zero (OK). If, however, any callback
* function returns a non-zero value, the traversal will be terminated and
* that non-zero value will be returned.
*
* Assumptions:
* The caller does NOT hold the lock on the module registry.
*
****************************************************************************/
int modlib_registry_foreach(mod_callback_t callback, FAR void *arg);
/****************************************************************************
* Name: modlib_freesymtab
*
* Description:
* Free a symbol table for the current module.
*
* Input Parameters:
* modp - Module state descriptor
*
****************************************************************************/
void modlib_freesymtab(FAR struct module_s *modp);
#endif /* __INCLUDE_NUTTX_LIB_MODLIB_H */