/* Thread-local storage handling in the ELF dynamic linker. i386 version. Copyright (C) 2004-2025 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, see . */ .hidden _dl_tlsdesc_dynamic .global _dl_tlsdesc_dynamic .type _dl_tlsdesc_dynamic,@function /* This function is used for symbols that need dynamic TLS. %eax points to the TLS descriptor, such that 0(%eax) points to _dl_tlsdesc_dynamic itself, and 4(%eax) points to a struct tlsdesc_dynamic_arg object. It must return in %eax the offset between the thread pointer and the object denoted by the argument, without clobbering any registers. The assembly code that follows is a rendition of the following C code, hand-optimized a little bit. ptrdiff_t __attribute__ ((__regparm__ (1))) _dl_tlsdesc_dynamic (struct tlsdesc *tdp) { struct tlsdesc_dynamic_arg *td = tdp->arg; dtv_t *dtv = *(dtv_t **)((char *)__thread_pointer + DTV_OFFSET); if (__builtin_expect (td->gen_count <= dtv[0].counter && (dtv[td->tlsinfo.ti_module].pointer.val != TLS_DTV_UNALLOCATED), 1)) return dtv[td->tlsinfo.ti_module].pointer.val + td->tlsinfo.ti_offset - __thread_pointer; return ___tls_get_addr (&td->tlsinfo) - __thread_pointer; } */ cfi_startproc .align 16 _dl_tlsdesc_dynamic: /* Like all TLS resolvers, preserve call-clobbered registers. We need two scratch regs anyway. */ subl $32, %esp cfi_adjust_cfa_offset (32) movl %ecx, 20(%esp) movl %edx, 24(%esp) movl TLSDESC_ARG(%eax), %eax movl %gs:DTV_OFFSET, %edx movl TLSDESC_GEN_COUNT(%eax), %ecx cmpl (%edx), %ecx ja 2f movl TLSDESC_MODID(%eax), %ecx movl (%edx,%ecx,8), %edx cmpl $-1, %edx je 2f movl TLSDESC_MODOFF(%eax), %eax addl %edx, %eax 1: movl 20(%esp), %ecx subl %gs:0, %eax movl 24(%esp), %edx addl $32, %esp cfi_adjust_cfa_offset (-32) ret .p2align 4,,7 2: #include "tls-get-addr-wrapper.h" jmp 1b cfi_endproc .size _dl_tlsdesc_dynamic, .-_dl_tlsdesc_dynamic #undef STATE_SAVE_ALIGNMENT