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-rw-r--r--sysdeps/x86_64/tls_get_addr.S61
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
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+++ b/sysdeps/x86_64/tls_get_addr.S
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+/* Stack-aligning implementation of __tls_get_addr. x86-64 version.
+ Copyright (C) 2017-2018 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 */