commit 4d4377881d462458de5d91840d11c10206e2e34d
author Paul Kirth <paulkirth@google.com> Tue Jan 30 23:03:14 2024 +0000
committer Paul Kirth <paulkirth@google.com> Fri Jun 07 14:30:22 2024 -0700
tree 9f240c235fa923c58b46cfe9567e69d718768f2d
parent b9279b62c2a128ceb4e9d86352a2d61ad1384bbd

[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

tests/elftls_dl_test.cpp

diff --git a/tests/elftls_dl_test.cpp b/tests/elftls_dl_test.cpp
index e759e15..e409b72 100644
--- a/tests/elftls_dl_test.cpp
+++ b/tests/elftls_dl_test.cpp
@@ -107,6 +107,22 @@
   void* lib = dlopen("libtest_elftls_dynamic.so", RTLD_LOCAL | RTLD_NOW);
   ASSERT_NE(nullptr, lib);
 
+  auto get_local_var2 = reinterpret_cast<int(*)()>(dlsym(lib, "get_local_var2"));
+  ASSERT_NE(nullptr, get_local_var2);
+
+  auto get_local_var1 = reinterpret_cast<int(*)()>(dlsym(lib, "get_local_var1"));
+  ASSERT_NE(nullptr, get_local_var1);
+
+  auto get_local_var1_addr = reinterpret_cast<int*(*)()>(dlsym(lib, "get_local_var1_addr"));
+  ASSERT_NE(nullptr, get_local_var1_addr);
+
+  // Make sure subsequent accesses return the same pointer.
+  ASSERT_EQ(get_local_var1_addr(), get_local_var1_addr());
+
+  // Check the initial values are correct.
+  ASSERT_EQ(25, get_local_var2());
+  ASSERT_EQ(15, get_local_var1());
+
   auto bump_local_vars = reinterpret_cast<int(*)()>(dlsym(lib, "bump_local_vars"));
   ASSERT_NE(nullptr, bump_local_vars);
 
@@ -135,7 +151,7 @@
 // TLSDESC, the result is NULL. With __tls_get_addr, the result is the
 // generation count (or maybe undefined behavior)? This test only tests TLSDESC.
 TEST(elftls_dl, tlsdesc_missing_weak) {
-#if defined(__aarch64__)
+#if defined(__aarch64__) || defined(__riscv)
   void* lib = dlopen("libtest_elftls_dynamic.so", RTLD_LOCAL | RTLD_NOW);
   ASSERT_NE(nullptr, lib);
 

tests/libs/elftls_dtv_resize_helper.cpp

diff --git a/tests/libs/elftls_dtv_resize_helper.cpp b/tests/libs/elftls_dtv_resize_helper.cpp
index 340d5df..7fb6fb5 100644
--- a/tests/libs/elftls_dtv_resize_helper.cpp
+++ b/tests/libs/elftls_dtv_resize_helper.cpp
@@ -180,8 +180,8 @@
   // Access a TLS variable from the first filler module.
   ASSERT_EQ(102, func1());
   ASSERT_EQ(5u, highest_modid_in_dtv());
-#if defined(__aarch64__)
-  // The arm64 TLSDESC resolver doesn't update the DTV if it is new enough for
+#if defined(__aarch64__) || defined(__riscv)
+  // The arm64 and riscv64 TLSDESC resolver doesn't update the DTV if it is new enough for
   // the given access.
   ASSERT_EQ(initial_dtv, dtv());
   ASSERT_EQ(5u, dtv()->count);

tests/libs/elftls_dynamic.cpp

diff --git a/tests/libs/elftls_dynamic.cpp b/tests/libs/elftls_dynamic.cpp
index 2500484..df3ad75 100644
--- a/tests/libs/elftls_dynamic.cpp
+++ b/tests/libs/elftls_dynamic.cpp
@@ -66,6 +66,18 @@
   return ++local_var_1 + ++local_var_2;
 }
 
+extern "C" int get_local_var1() {
+  return local_var_1;
+}
+
+extern "C" int* get_local_var1_addr() {
+  return &local_var_1;
+}
+
+extern "C" int get_local_var2() {
+  return local_var_2;
+}
+
 __attribute__((weak)) extern "C" __thread int missing_weak_dyn_tls;
 
 extern "C" int* missing_weak_dyn_tls_addr() {