diff options
Diffstat (limited to 'cpukit/include/rtems/score/tls.h')
| -rw-r--r-- | cpukit/include/rtems/score/tls.h | 120 |
1 files changed, 67 insertions, 53 deletions
diff --git a/cpukit/include/rtems/score/tls.h b/cpukit/include/rtems/score/tls.h index abb0a748ad..8716c5230c 100644 --- a/cpukit/include/rtems/score/tls.h +++ b/cpukit/include/rtems/score/tls.h @@ -10,7 +10,7 @@ */ /* - * Copyright (C) 2014, 2022 embedded brains GmbH + * Copyright (C) 2014, 2023 embedded brains GmbH & Co. KG * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions @@ -59,31 +59,51 @@ extern "C" { * @{ */ -extern char _TLS_Data_begin[]; - -extern char _TLS_Data_end[]; +/** + * @brief Represents the TLS configuration. + */ +typedef struct { + /** + * @brief This member is initialized to _TLS_Data_begin. + */ + const char *data_begin; -extern char _TLS_Data_size[]; + /** + * @brief This member is initialized to _TLS_Data_size. + */ + const char *data_size; -extern char _TLS_BSS_begin[]; + /** + * @brief This member is initialized to _TLS_BSS_begin. + */ + const char *bss_begin; -extern char _TLS_BSS_end[]; + /** + * @brief This member is initialized to _TLS_BSS_size. + */ + const char *bss_size; -extern char _TLS_BSS_size[]; + /** + * @brief This member is initialized to _TLS_Size. + */ + const char *size; -extern char _TLS_Size[]; + /** + * @brief This member is initialized to _TLS_Alignment. + */ + const char *alignment; +} TLS_Configuration; /** - * @brief The TLS section alignment. + * @brief Provides the TLS configuration. * - * This symbol is provided by the linker command file as the maximum alignment - * of the .tdata and .tbss sections. The linker ensures that the first TLS - * output section is aligned to the maximum alignment of all TLS output - * sections, see function _bfd_elf_tls_setup() in bfd/elflink.c of the GNU - * Binutils sources. The linker command file must take into account the case - * that the .tdata section is empty and the .tbss section is non-empty. + * Directly using symbols with an arbitrary absolute address such as + * _TLS_Alignment may not work with all code models (for example the AArch64 + * tiny and small code models). Store the addresses in a read-only object. + * Using the volatile qualifier ensures that the compiler actually loads the + * address from the object. */ -extern char _TLS_Alignment[]; +extern const volatile TLS_Configuration _TLS_Configuration; typedef struct { /* @@ -116,38 +136,24 @@ typedef struct { } TLS_Index; /** - * @brief Gets the size of the thread-local storage data in bytes. - * - * @return Returns the size of the thread-local storage data in bytes. - */ -static inline uintptr_t _TLS_Get_size( void ) -{ - uintptr_t size; - - /* - * We must be careful with using _TLS_Size here since this could lead GCC to - * assume that this symbol is not 0 and the tests for 0 will be optimized - * away. - */ - size = (uintptr_t) _TLS_Size; - RTEMS_OBFUSCATE_VARIABLE( size ); - return size; -} - -/** * @brief Gets the size of the thread control block area in bytes. * + * @param config is the TLS configuration. + * * @return Returns the size of the thread control block area in bytes. */ -static inline uintptr_t _TLS_Get_thread_control_block_area_size( void ) +static inline uintptr_t _TLS_Get_thread_control_block_area_size( + const volatile TLS_Configuration *config +) { #if CPU_THREAD_LOCAL_STORAGE_VARIANT == 11 uintptr_t alignment; - alignment = (uintptr_t) _TLS_Alignment; + alignment = (uintptr_t) config->alignment; return RTEMS_ALIGN_UP( sizeof( TLS_Thread_control_block ), alignment ); #else + (void) config; return sizeof( TLS_Thread_control_block ); #endif } @@ -163,17 +169,23 @@ uintptr_t _TLS_Get_allocation_size( void ); /** * @brief Initializes the thread-local storage data. * + * @param config is the TLS configuration. + * * @param[out] tls_data is the thread-local storage data to initialize. */ -static inline void _TLS_Copy_and_clear( void *tls_data ) +static inline void _TLS_Copy_and_clear( + const volatile TLS_Configuration *config, + void *tls_data +) { - tls_data = memcpy( tls_data, _TLS_Data_begin, (uintptr_t) _TLS_Data_size ); + tls_data = + memcpy( tls_data, config->data_begin, (uintptr_t) config->data_size ); memset( (char *) tls_data + - (uintptr_t) _TLS_BSS_begin - (uintptr_t) _TLS_Data_begin, + (uintptr_t) config->bss_begin - (uintptr_t) config->data_begin, 0, - (uintptr_t) _TLS_BSS_size + (uintptr_t) config->bss_size ); } @@ -213,20 +225,22 @@ static inline void _TLS_Initialize_TCB_and_DTV( */ static inline void *_TLS_Initialize_area( void *tls_area ) { - uintptr_t alignment; - void *tls_data; - TLS_Thread_control_block *tcb; - TLS_Dynamic_thread_vector *dtv; - void *return_value; + const volatile TLS_Configuration *config; + uintptr_t alignment; + void *tls_data; + TLS_Thread_control_block *tcb; + TLS_Dynamic_thread_vector *dtv; + void *return_value; #if CPU_THREAD_LOCAL_STORAGE_VARIANT == 11 - uintptr_t tcb_size; + uintptr_t tcb_size; #endif #if CPU_THREAD_LOCAL_STORAGE_VARIANT == 20 - uintptr_t size; - uintptr_t alignment_2; + uintptr_t size; + uintptr_t alignment_2; #endif - alignment = (uintptr_t) _TLS_Alignment; + config = &_TLS_Configuration; + alignment = (uintptr_t) config->alignment; #ifdef __i386__ dtv = NULL; @@ -249,7 +263,7 @@ static inline void *_TLS_Initialize_area( void *tls_area ) #elif CPU_THREAD_LOCAL_STORAGE_VARIANT == 20 alignment_2 = RTEMS_ALIGN_UP( alignment, CPU_SIZEOF_POINTER ); tls_area = (void *) RTEMS_ALIGN_UP( (uintptr_t) tls_area, alignment_2 ); - size = _TLS_Get_size(); + size = (uintptr_t) config->size; tcb = (TLS_Thread_control_block *) ((char *) tls_area + RTEMS_ALIGN_UP( size, alignment_2 )); tls_data = (char *) tcb - RTEMS_ALIGN_UP( size, alignment ); @@ -259,7 +273,7 @@ static inline void *_TLS_Initialize_area( void *tls_area ) #endif _TLS_Initialize_TCB_and_DTV( tls_data, tcb, dtv ); - _TLS_Copy_and_clear( tls_data ); + _TLS_Copy_and_clear( config, tls_data ); return return_value; } |