Add ARM EABI function __aeabi_read_tp
By default, Clang uses this arm32 function to read the thread pointer,
either for ELF TLS or via __builtin_thread_pointer(). It's probably better
to inline the cp15 access using -mtp=cp15, but that's not the default yet.
See https://reviews.llvm.org/D34878?id=114573.
Bug: http://b/78026329
Test: bionic unit tests
Change-Id: I93b8926075f0b2cea8df9ef518d54f2820a8ff5b
diff --git a/libc/Android.bp b/libc/Android.bp
index 3e607f6..01c0cad 100644
--- a/libc/Android.bp
+++ b/libc/Android.bp
@@ -760,6 +760,7 @@
"arch-arm/generic/bionic/strcpy.S",
"arch-arm/generic/bionic/strlen.c",
+ "arch-arm/bionic/__aeabi_read_tp.S",
"arch-arm/bionic/atomics_arm.c",
"arch-arm/bionic/__bionic_clone.S",
"arch-arm/bionic/_exit_with_stack_teardown.S",
diff --git a/libc/NOTICE b/libc/NOTICE
index 40a5704..120c4fd 100644
--- a/libc/NOTICE
+++ b/libc/NOTICE
@@ -1068,6 +1068,34 @@
-------------------------------------------------------------------
+Copyright (C) 2019 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.
+
+-------------------------------------------------------------------
+
Copyright (c) 1980, 1983, 1988, 1993
The Regents of the University of California. All rights reserved.
diff --git a/libc/arch-arm/bionic/__aeabi_read_tp.S b/libc/arch-arm/bionic/__aeabi_read_tp.S
new file mode 100644
index 0000000..f6f9757
--- /dev/null
+++ b/libc/arch-arm/bionic/__aeabi_read_tp.S
@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2018 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.
+ */
+
+#include <private/bionic_asm.h>
+
+// For arm32 and -mtp=soft, the compiler uses this function to read the thread
+// pointer for ELF TLS accesses. With -mtp=cp15, the compiler inlines the call
+// instead. GCC defaults to -mtp=auto, which inlines this function with
+// -march=armv7-a. Clang does not yet implement -mtp=auto, and instead defaults
+// to -mtp=soft.
+// - https://bugs.llvm.org/show_bug.cgi?id=38394.
+// - https://reviews.llvm.org/D34878?id=114573.
+//
+// This function must preserve every register except r0, ip, lr, and cpsr.
+//
+// See "Run-time ABI for the ARM Architecture"
+// http://infocenter.arm.com/help/topic/com.arm.doc.ihi0043d/IHI0043D_rtabi.pdf
+//
+ENTRY(__aeabi_read_tp)
+ // __get_tls()
+ mrc p15, 0, r0, c13, c0, 3
+ bx lr
+END(__aeabi_read_tp)
diff --git a/libc/libc.map.txt b/libc/libc.map.txt
index 4b8463f..f78014d 100644
--- a/libc/libc.map.txt
+++ b/libc/libc.map.txt
@@ -1446,6 +1446,7 @@
LIBC_Q { # introduced=Q
global:
+ __aeabi_read_tp; # arm
__res_randomid;
android_fdsan_close_with_tag;
android_fdsan_create_owner_tag;
diff --git a/tests/Android.bp b/tests/Android.bp
index 899fc66..7d56a22 100644
--- a/tests/Android.bp
+++ b/tests/Android.bp
@@ -64,6 +64,7 @@
name: "libBionicStandardTests",
defaults: ["bionic_tests_defaults"],
srcs: [
+ "__aeabi_read_tp_test.cpp",
"alloca_test.cpp",
"android_get_device_api_level.cpp",
"arpa_inet_test.cpp",
diff --git a/tests/__aeabi_read_tp_test.cpp b/tests/__aeabi_read_tp_test.cpp
new file mode 100644
index 0000000..ab96af9
--- /dev/null
+++ b/tests/__aeabi_read_tp_test.cpp
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2019 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.
+ */
+
+#include <gtest/gtest.h>
+
+#include "private/__get_tls.h"
+
+#if defined(__arm__)
+extern "C" void* __aeabi_read_tp();
+TEST(aeabi, read_tp) {
+ ASSERT_EQ(__aeabi_read_tp(), static_cast<void*>(__get_tls()));
+}
+#endif
