diff options
Diffstat (limited to 'sysdeps/generic')
| -rw-r--r-- | sysdeps/generic/dl-tls.c | 155 | ||||
| -rw-r--r-- | sysdeps/generic/dl-tls.h | 2 | ||||
| -rw-r--r-- | sysdeps/generic/ldsodefs.h | 17 |
3 files changed, 171 insertions, 3 deletions
diff --git a/sysdeps/generic/dl-tls.c b/sysdeps/generic/dl-tls.c new file mode 100644 index 0000000000..557a023453 --- /dev/null +++ b/sysdeps/generic/dl-tls.c @@ -0,0 +1,155 @@ +/* Thread-local storage handling in the ELF dynamic linker. Generic version. + Copyright (C) 2002 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <assert.h> + +#include <dl-tls.h> +#include <ldsodefs.h> + + +/* We don't need any of this if TLS is not supported. */ +#ifdef USE_TLS + +/* Value used for dtv entries for which the allocation is delayed. */ +# define TLS_DTV_UNALLOCATE ((void *) -1l) + + +size_t +internal_function +_dl_next_tls_modid (void) +{ + size_t result; + + if (__builtin_expect (GL(dl_tls_dtv_gaps), false)) + { + /* XXX If this method proves too costly we can optimize + it to use a constant time method. But I don't think + it's a problem. */ + struct link_map *runp = GL(dl_initimage_list); + bool used[GL(dl_tls_max_dtv_idx)]; + + assert (runp != NULL); + do + { + assert (runp->l_tls_modid > 0 + && runp->l_tls_modid <= GL(dl_tls_max_dtv_idx)); + used[runp->l_tls_modid - 1] = true; + } + while ((runp = runp->l_tls_nextimage) != GL(dl_initimage_list)); + + result = 0; + do + /* The information about the gaps is pessimistic. It might be + there are actually none. */ + if (result >= GL(dl_tls_max_dtv_idx)) + { + /* Now we know there is actually no gap. Bump the maximum + ID number and remember that there are no gaps. */ + result = ++GL(dl_tls_max_dtv_idx); + GL(dl_tls_dtv_gaps) = false; + break; + } + while (used[result++]); + } + else + /* No gaps, allocate a new entry. */ + result = ++GL(dl_tls_max_dtv_idx); + + return result; +} + + +void +internal_function +_dl_determine_tlsoffset (struct link_map *firstp) +{ + struct link_map *runp = firstp; + size_t max_align = 0; + size_t offset; + +# if TLS_TCB_AT_TP + /* We simply start with zero. */ + offset = 0; + + do + { + max_align = MAX (max_align, runp->l_tls_align); + + /* Compute the offset of the next TLS block. */ + offset = roundup (offset + runp->l_tls_blocksize, runp->l_tls_align); + + /* XXX For some architectures we perhaps should store the + negative offset. */ + runp->l_tls_offset = offset; + } + while ((runp = runp->l_tls_nextimage) != firstp); +# elif TLS_DTV_AT_TP + struct link_map *lastp; + + /* The first block starts right after the TCB. */ + offset = TLS_TCB_SIZE; + max_align = runp->l_tls_align; + runp->l_tls_offset = offset; + lastp = runp; + + while ((runp = runp->l_tls_nextimage) != firstp) + { + max_align = MAX (max_align, runp->l_tls_align); + + /* Compute the offset of the next TLS block. */ + offset = roundup (offset + lastp->l_tls_blocksize, runp->l_tls_align); + + runp->l_tls_offset = offset; + } +# else +# error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined" +# endif +} + + +/* The __tls_get_addr function has two basic forms which differ in the + arguments. The IA-64 form takes two parameters, the module ID and + offset. The form used, among others, on IA-32 takes a reference to + a special structure which contain the same information. The second + form seems to be more often used (in the moment) so we default to + it. Users of the IA-64 form have to provide adequate definitions + of the following macros. */ +# ifndef GET_ADDR_ARGS +# define GET_ADDR_ARGS struct tls_index *ti +# endif +# ifndef GET_ADDR_MODULE +# define GET_ADDR_MODULE ti->ti_module +# endif +# ifndef GET_ADDR_OFFSET +# define GET_ADDR_OFFSET ti->ti_offset +# endif + + +void * +__tls_get_addr (GET_ADDR_ARGS) +{ + dtv_t *dtv = THREAD_DTV (); + + if (dtv[GET_ADDR_MODULE].pointer == TLS_DTV_UNALLOCATE) + /* XXX */; + + return (char *) dtv[GET_ADDR_MODULE].pointer + GET_ADDR_OFFSET; +} + +#endif /* use TLS */ diff --git a/sysdeps/generic/dl-tls.h b/sysdeps/generic/dl-tls.h new file mode 100644 index 0000000000..7703a97525 --- /dev/null +++ b/sysdeps/generic/dl-tls.h @@ -0,0 +1,2 @@ +/* There has to be an architecture specific version of this file. */ +#error "architecture-specific version of <dl-tls.h> missing" diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h index 75f82bdd95..9913820b03 100644 --- a/sysdeps/generic/ldsodefs.h +++ b/sysdeps/generic/ldsodefs.h @@ -22,6 +22,7 @@ #include <features.h> +#include <stdbool.h> #define __need_size_t #define __need_NULL #include <stddef.h> @@ -230,7 +231,7 @@ struct rtld_global #define DL_DEBUG_RELOC (1 << 5) #define DL_DEBUG_FILES (1 << 6) #define DL_DEBUG_STATISTICS (1 << 7) -/* This one is used only internally. */ +/* These two are used only internally. */ #define DL_DEBUG_HELP (1 << 8) #define DL_DEBUG_PRELINK (1 << 9) @@ -293,8 +294,10 @@ struct rtld_global initialize new TLS blocks. */ EXTERN struct link_map *_dl_initimage_list; - /* Count the number of modules which define TLS data. */ - EXTERN size_t _dl_tls_module_cnt; + /* Highest dtv index currently needed. */ + EXTERN size_t _dl_tls_max_dtv_idx; + /* Flag signalling whether there are gaps in the module ID allocation. */ + EXTERN bool _dl_tls_dtv_gaps; #endif /* Name of the shared object to be profiled (if any). */ @@ -651,6 +654,14 @@ extern void _dl_sysdep_start_cleanup (void) internal_function; +/* Determine next available module ID. */ +extern size_t _dl_next_tls_modid (void) internal_function; + +/* Calculate offset of the TLS blocks in the static TLS block. */ +extern void _dl_determine_tlsoffset (struct link_map *firstp) + internal_function; + + __END_DECLS #endif /* ldsodefs.h */ |