diff options
Diffstat (limited to 'sysdeps/x86_64/tls_get_addr.S')
-rw-r--r-- | sysdeps/x86_64/tls_get_addr.S | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/sysdeps/x86_64/tls_get_addr.S b/sysdeps/x86_64/tls_get_addr.S new file mode 100644 index 0000000000..9d38fb3be5 --- /dev/null +++ b/sysdeps/x86_64/tls_get_addr.S @@ -0,0 +1,61 @@ +/* Stack-aligning implementation of __tls_get_addr. x86-64 version. + Copyright (C) 2017 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 + <http://www.gnu.org/licenses/>. */ + +#ifdef SHARED + +# include <sysdep.h> +# include "tlsdesc.h" +# include "rtld-offsets.h" + +/* See __tls_get_addr and __tls_get_addr_slow in dl-tls.c. This function + call __tls_get_addr_slow on both slow paths. It realigns the stack + before the call to work around GCC PR58066. */ + +ENTRY (__tls_get_addr) + mov %fs:DTV_OFFSET, %RDX_LP + mov GL_TLS_GENERATION_OFFSET+_rtld_local(%rip), %RAX_LP + /* GL(dl_tls_generation) == dtv[0].counter */ + cmp %RAX_LP, (%rdx) + jne 1f + mov TI_MODULE_OFFSET(%rdi), %RAX_LP + /* dtv[ti->ti_module] */ +# ifdef __LP64__ + salq $4, %rax + movq (%rdx,%rax), %rax +# else + movl (%rdx,%rax, 8), %eax +# endif + cmp $-1, %RAX_LP + je 1f + add TI_OFFSET_OFFSET(%rdi), %RAX_LP + ret +1: + /* On the slow path, align the stack. */ + pushq %rbp + cfi_def_cfa_offset (16) + cfi_offset (%rbp, -16) + mov %RSP_LP, %RBP_LP + cfi_def_cfa_register (%rbp) + and $-16, %RSP_LP + call __tls_get_addr_slow + mov %RBP_LP, %RSP_LP + popq %rbp + cfi_def_cfa (%rsp, 8) + ret +END (__tls_get_addr) +#endif /* SHARED */ |