diff options
Diffstat (limited to 'elf/rtld.c')
| -rw-r--r-- | elf/rtld.c | 138 |
1 files changed, 135 insertions, 3 deletions
diff --git a/elf/rtld.c b/elf/rtld.c index 0af932579a..b3959a34d0 100644 --- a/elf/rtld.c +++ b/elf/rtld.c @@ -306,9 +306,21 @@ _dl_start_final (void *arg, struct dl_start_final_info *info) GL(dl_rtld_map).l_text_end = (ElfW(Addr)) _etext; /* Copy the TLS related data if necessary. */ #ifndef DONT_USE_BOOTSTRAP_MAP -# if NO_TLS_OFFSET != 0 +# if USE___THREAD + assert (info->l.l_tls_modid != 0); + GL(dl_rtld_map).l_tls_blocksize = info->l.l_tls_blocksize; + GL(dl_rtld_map).l_tls_align = info->l.l_tls_align; + GL(dl_rtld_map).l_tls_firstbyte_offset = info->l.l_tls_firstbyte_offset; + GL(dl_rtld_map).l_tls_initimage_size = info->l.l_tls_initimage_size; + GL(dl_rtld_map).l_tls_initimage = info->l.l_tls_initimage; + GL(dl_rtld_map).l_tls_offset = info->l.l_tls_offset; + GL(dl_rtld_map).l_tls_modid = 1; +# else +# if NO_TLS_OFFSET != 0 GL(dl_rtld_map).l_tls_offset = NO_TLS_OFFSET; +# endif # endif + #endif #if HP_TIMING_AVAIL @@ -390,6 +402,9 @@ _dl_start (void *arg) ++cnt) bootstrap_map.l_info[cnt] = 0; # endif +# if USE___THREAD + bootstrap_map.l_tls_modid = 0; +# endif #endif /* Figure out the run-time load address of the dynamic linker itself. */ @@ -403,6 +418,123 @@ _dl_start (void *arg) bootstrap_map.l_tls_offset = NO_TLS_OFFSET; #endif + /* Get the dynamic linker's own program header. First we need the ELF + file header. The `_begin' symbol created by the linker script points + to it. When we have something like GOTOFF relocs, we can use a plain + reference to find the runtime address. Without that, we have to rely + on the `l_addr' value, which is not the value we want when prelinked. */ +#if USE___THREAD + dtv_t initdtv[3]; + ElfW(Ehdr) *ehdr +# ifdef DONT_USE_BOOTSTRAP_MAP + = (ElfW(Ehdr) *) &_begin; +# else +# error This will not work with prelink. + = (ElfW(Ehdr) *) bootstrap_map.l_addr; +# endif + ElfW(Phdr) *phdr = (ElfW(Phdr) *) ((void *) ehdr + ehdr->e_phoff); + size_t cnt = ehdr->e_phnum; /* PT_TLS is usually the last phdr. */ + while (cnt-- > 0) + if (phdr[cnt].p_type == PT_TLS) + { + void *tlsblock; + size_t max_align = MAX (TLS_INIT_TCB_ALIGN, phdr[cnt].p_align); + char *p; + + bootstrap_map.l_tls_blocksize = phdr[cnt].p_memsz; + bootstrap_map.l_tls_align = phdr[cnt].p_align; + if (phdr[cnt].p_align == 0) + bootstrap_map.l_tls_firstbyte_offset = 0; + else + bootstrap_map.l_tls_firstbyte_offset = (phdr[cnt].p_vaddr + & (phdr[cnt].p_align - 1)); + assert (bootstrap_map.l_tls_blocksize != 0); + bootstrap_map.l_tls_initimage_size = phdr[cnt].p_filesz; + bootstrap_map.l_tls_initimage = (void *) (bootstrap_map.l_addr + + phdr[cnt].p_vaddr); + + /* We can now allocate the initial TLS block. This can happen + on the stack. We'll get the final memory later when we + know all about the various objects loaded at startup + time. */ +# if TLS_TCB_AT_TP + tlsblock = alloca (roundup (bootstrap_map.l_tls_blocksize, + TLS_INIT_TCB_ALIGN) + + TLS_INIT_TCB_SIZE + + max_align); +# elif TLS_DTV_AT_TP + tlsblock = alloca (roundup (TLS_INIT_TCB_SIZE, + bootstrap_map.l_tls_align) + + bootstrap_map.l_tls_blocksize + + max_align); +# else + /* In case a model with a different layout for the TCB and DTV + is defined add another #elif here and in the following #ifs. */ +# error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined" +# endif + /* Align the TLS block. */ + tlsblock = (void *) (((uintptr_t) tlsblock + max_align - 1) + & ~(max_align - 1)); + + /* Initialize the dtv. [0] is the length, [1] the generation + counter. */ + initdtv[0].counter = 1; + initdtv[1].counter = 0; + + /* Initialize the TLS block. */ +# if TLS_TCB_AT_TP + initdtv[2].pointer = tlsblock; +# elif TLS_DTV_AT_TP + bootstrap_map.l_tls_offset = roundup (TLS_INIT_TCB_SIZE, + bootstrap_map.l_tls_align); + initdtv[2].pointer = (char *) tlsblock + bootstrap_map.l_tls_offset; +# else +# error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined" +# endif + p = __mempcpy (initdtv[2].pointer, bootstrap_map.l_tls_initimage, + bootstrap_map.l_tls_initimage_size); +# ifdef HAVE_BUILTIN_MEMSET + __builtin_memset (p, '\0', (bootstrap_map.l_tls_blocksize + - bootstrap_map.l_tls_initimage_size)); +# else + { + size_t remaining = (bootstrap_map.l_tls_blocksize + - bootstrap_map.l_tls_initimage_size); + while (remaining-- > 0) + *p++ = '\0'; + } +# endif + + /* Install the pointer to the dtv. */ + + /* Initialize the thread pointer. */ +# if TLS_TCB_AT_TP + bootstrap_map.l_tls_offset + = roundup (bootstrap_map.l_tls_blocksize, TLS_INIT_TCB_ALIGN); + + INSTALL_DTV ((char *) tlsblock + bootstrap_map.l_tls_offset, + initdtv); + + const char *lossage = TLS_INIT_TP ((char *) tlsblock + + bootstrap_map.l_tls_offset, 0); +# elif TLS_DTV_AT_TP + INSTALL_DTV (tlsblock, initdtv); + const char *lossage = TLS_INIT_TP (tlsblock, 0); +# else +# error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined" +# endif + if (__builtin_expect (lossage != NULL, 0)) + _dl_fatal_printf ("cannot set up thread-local storage: %s\n", + lossage); + + /* So far this is module number one. */ + bootstrap_map.l_tls_modid = 1; + + /* There can only be one PT_TLS entry. */ + break; + } +#endif /* USE___THREAD */ + #ifdef ELF_MACHINE_BEFORE_RTLD_RELOC ELF_MACHINE_BEFORE_RTLD_RELOC (bootstrap_map.l_info); #endif @@ -647,7 +779,7 @@ cannot allocate TLS data structures for initial thread"); /* And finally install it for the main thread. If ld.so itself uses TLS we know the thread pointer was initialized earlier. */ - const char *lossage = TLS_INIT_TP (tcbp, 0); + const char *lossage = TLS_INIT_TP (tcbp, USE___THREAD); if (__builtin_expect (lossage != NULL, 0)) _dl_fatal_printf ("cannot set up thread-local storage: %s\n", lossage); tls_init_tp_called = true; @@ -2178,7 +2310,7 @@ ERROR: ld.so: object '%s' cannot be loaded as audit interface: %s; ignored.\n", TLS we know the thread pointer was initialized earlier. */ if (! tls_init_tp_called) { - const char *lossage = TLS_INIT_TP (tcbp, 0); + const char *lossage = TLS_INIT_TP (tcbp, USE___THREAD); if (__builtin_expect (lossage != NULL, 0)) _dl_fatal_printf ("cannot set up thread-local storage: %s\n", lossage); |