[riscv][bionic] Prototype TLS Descriptor support
Add basic assembly stubs for TLS Descriptor support in the dynamic
linker, and enable several code paths related to TLSDESC for RISC-V.
Note: This patch requires an updated toolchain that supports TLSDESC
for RISC-V, and the `-mtls-dialect=` compiler option specifically.
Test: adb shell /data/nativetest64/bionic-unit-tests/bionic-unit-tests --gtest_filter=*tls*
Bug: 322984914
Change-Id: I74bd0fa216b44b4ca2c5a5a6aec37b3fc47b00d9
diff --git a/libc/private/bionic_elf_dtv_offset.h b/libc/private/bionic_elf_dtv_offset.h
new file mode 100644
index 0000000..8d9f3b9
--- /dev/null
+++ b/libc/private/bionic_elf_dtv_offset.h
@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#pragma once
+
+#if defined(__riscv)
+// TLS_DTV_OFFSET is a constant used in relocation fields, defined in RISC-V ELF Specification[1]
+// The front of the TCB contains a pointer to the DTV, and each pointer in DTV
+// points to 0x800 past the start of a TLS block to make full use of the range
+// of load/store instructions, refer to [2].
+//
+// [1]: RISC-V ELF Specification.
+// https://github.com/riscv-non-isa/riscv-elf-psabi-doc/blob/master/riscv-elf.adoc#constants
+// [2]: Documentation of TLS data structures
+// https://github.com/riscv-non-isa/riscv-elf-psabi-doc/issues/53
+#define TLS_DTV_OFFSET 0x800
+#else
+#define TLS_DTV_OFFSET 0
+#endif
diff --git a/libc/private/bionic_elf_tls.h b/libc/private/bionic_elf_tls.h
index 8bd5bc5..04297ad 100644
--- a/libc/private/bionic_elf_tls.h
+++ b/libc/private/bionic_elf_tls.h
@@ -34,6 +34,8 @@
#include <stdint.h>
#include <sys/cdefs.h>
+#include "bionic_elf_dtv_offset.h"
+
__LIBC_HIDDEN__ extern _Atomic(size_t) __libc_tls_generation_copy;
struct TlsAlign {
@@ -227,17 +229,3 @@
void __free_dynamic_tls(bionic_tcb* tcb);
void __notify_thread_exit_callbacks();
-#if defined(__riscv)
-// TLS_DTV_OFFSET is a constant used in relocation fields, defined in RISC-V ELF Specification[1]
-// The front of the TCB contains a pointer to the DTV, and each pointer in DTV
-// points to 0x800 past the start of a TLS block to make full use of the range
-// of load/store instructions, refer to [2].
-//
-// [1]: RISC-V ELF Specification.
-// https://github.com/riscv-non-isa/riscv-elf-psabi-doc/blob/master/riscv-elf.adoc#constants
-// [2]: Documentation of TLS data structures
-// https://github.com/riscv-non-isa/riscv-elf-psabi-doc/issues/53
-#define TLS_DTV_OFFSET 0x800
-#else
-#define TLS_DTV_OFFSET 0
-#endif