[libc] implement vdso

libc/hdr/CMakeLists.txt

@@ -143,4 +143,22 @@ add_proxy_header_library(
     libc.include.llvm-libc-macros.limits_macros
 )
 
+add_proxy_header_library(
+  link_macros
+  HDRS
+    link_macros.h
+  FULL_BUILD_DEPENDS
+    libc.include.llvm-libc-macros.link_macros
+    libc.include.link
+)
+
+add_proxy_header_library(
+  sys_auxv_macros
+  HDRS
+    sys_auxv_macros.h
+  FULL_BUILD_DEPENDS
+    libc.include.llvm-libc-macros.sys_auxv_macros
+    libc.include.sys_auxv
+)
+
 add_subdirectory(types)

libc/hdr/link_macros.h

@@ -0,0 +1,22 @@
+//===-- Definition of macros from link.h ----------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_HDR_LINK_MACROS_H
+#define LLVM_LIBC_HDR_LINK_MACROS_H
+
+#ifdef LIBC_FULL_BUILD
+
+#include "include/llvm-libc-macros/link-macros.h"
+
+#else // Overlay mode
+
+#include <link.h>
+
+#endif // LLVM_LIBC_FULL_BUILD
+
+#endif // LLVM_LIBC_HDR_LINK_MACROS_H

libc/hdr/sys_auxv_macros.h

@@ -0,0 +1,22 @@
+//===-- Definition of macros from sys/auxv.h ------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_HDR_SYS_AUXV_MACROS_H
+#define LLVM_LIBC_HDR_SYS_AUXV_MACROS_H
+
+#ifdef LIBC_FULL_BUILD
+
+#include "include/llvm-libc-macros/sys-auxv-macros.h"
+
+#else // Overlay mode
+
+#include <sys/auxv.h>
+
+#endif // LLVM_LIBC_FULL_BUILD
+
+#endif // LLVM_LIBC_HDR_SYS_AUXV_MACROS_H

libc/src/__support/OSUtil/linux/CMakeLists.txt

@@ -23,3 +23,33 @@ add_object_library(
     libc.hdr.types.struct_f_owner_ex
     libc.hdr.types.off_t
 )
+
+add_header_library(
+  vdso_sym
+  HDRS
+    vdso_sym.h
+  DEPENDS
+    libc.src.__support.common
+)
+
+add_object_library(
+  vdso
+  HDRS
+    vdso.h
+  SRCS
+    vdso.cpp
+  DEPENDS
+    .${LIBC_TARGET_ARCHITECTURE}.vdso
+    libc.src.__support.CPP.array
+    libc.src.__support.CPP.optional
+    libc.src.__support.CPP.string_view
+    libc.src.__support.threads.callonce
+    libc.src.__support.threads.linux.futex_word_type
+    libc.hdr.types.struct_timeval
+    libc.hdr.types.struct_timespec
+    libc.hdr.types.clockid_t
+    libc.hdr.types.time_t
+    libc.hdr.link_macros
+    libc.src.errno.errno
+    libc.src.sys.auxv.getauxval
+)

libc/src/__support/OSUtil/linux/aarch64/CMakeLists.txt

@@ -5,3 +5,13 @@ add_header_library(
   DEPENDS
     libc.src.__support.common
 )
+
+add_header_library(
+  vdso
+  HDRS
+    vdso.h
+  DEPENDS
+    libc.src.__support.common
+    libc.src.__support.CPP.string_view
+    libc.src.__support.OSUtil.linux.vdso_sym
+)

libc/src/__support/OSUtil/linux/aarch64/vdso.h

@@ -0,0 +1,37 @@
+//===---------- aarch64 vdso configuration ------------------------* C++ *-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+#ifndef LLVM_LIBC_SRC___SUPPORT_OSUTIL_LINUX_AARCH64_VDSO_H
+#define LLVM_LIBC_SRC___SUPPORT_OSUTIL_LINUX_AARCH64_VDSO_H
+#include "src/__support/CPP/string_view.h"
+#include "src/__support/OSUtil/linux/vdso_sym.h"
+namespace LIBC_NAMESPACE_DECL {
+namespace vdso {
+// translate VDSOSym to symbol names
+// https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm64/kernel/vdso/vdso.lds.S
+LIBC_INLINE constexpr cpp::string_view symbol_name(VDSOSym sym) {
+  switch (sym) {
+  case VDSOSym::RTSigReturn:
+    return "__kernel_rt_sigreturn";
+  case VDSOSym::GetTimeOfDay:
+    return "__kernel_gettimeofday";
+  case VDSOSym::ClockGetTime:
+    return "__kernel_clock_gettime";
+  case VDSOSym::ClockGetRes:
+    return "__kernel_clock_getres";
+  default:
+    return "";
+  }
+}
+
+// symbol versions
+LIBC_INLINE constexpr cpp::string_view symbol_version(VDSOSym) {
+  return "LINUX_2.6.39";
+}
+} // namespace vdso
+} // namespace LIBC_NAMESPACE_DECL
+#endif // LLVM_LIBC_SRC___SUPPORT_OSUTIL_LINUX_AARCH64_VDSO_H

libc/src/__support/OSUtil/linux/arm/CMakeLists.txt

@@ -5,3 +5,13 @@ add_header_library(
   DEPENDS
     libc.src.__support.common
 )
+
+add_header_library(
+  vdso
+  HDRS
+    vdso.h
+  DEPENDS
+    libc.src.__support.common
+    libc.src.__support.CPP.string_view
+    libc.src.__support.OSUtil.linux.vdso_sym
+)

libc/src/__support/OSUtil/linux/arm/vdso.h

@@ -0,0 +1,37 @@
+//===---------- arm vdso configuration ----------------------------* C++ *-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+#ifndef LLVM_LIBC_SRC___SUPPORT_OSUTIL_LINUX_ARM_VDSO_H
+#define LLVM_LIBC_SRC___SUPPORT_OSUTIL_LINUX_ARM_VDSO_H
+#include "src/__support/CPP/string_view.h"
+#include "src/__support/OSUtil/linux/vdso_sym.h"
+namespace LIBC_NAMESPACE_DECL {
+namespace vdso {
+// translate VDSOSym to symbol names
+// https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm/vdso/vdso.lds.S
+LIBC_INLINE constexpr cpp::string_view symbol_name(VDSOSym sym) {
+  switch (sym) {
+  case VDSOSym::ClockGetTime:
+    return "__vdso_clock_gettime";
+  case VDSOSym::GetTimeOfDay:
+    return "__vdso_gettimeofday";
+  case VDSOSym::ClockGetRes:
+    return "__vdso_clock_getres";
+  case VDSOSym::ClockGetTime64:
+    return "__vdso_clock_gettime64";
+  default:
+    return "";
+  }
+}
+
+// symbol versions
+LIBC_INLINE constexpr cpp::string_view symbol_version(VDSOSym) {
+  return "LINUX_2.6";
+}
+} // namespace vdso
+} // namespace LIBC_NAMESPACE_DECL
+#endif // LLVM_LIBC_SRC___SUPPORT_OSUTIL_LINUX_ARM_VDSO_H

libc/src/__support/OSUtil/linux/riscv/CMakeLists.txt

@@ -5,3 +5,13 @@ add_header_library(
   DEPENDS
     libc.src.__support.common
 )
+
+add_header_library(
+  vdso
+  HDRS
+    vdso.h
+  DEPENDS
+    libc.src.__support.common
+    libc.src.__support.CPP.string_view
+    libc.src.__support.OSUtil.linux.vdso_sym
+)

libc/src/__support/OSUtil/linux/riscv/vdso.h

@@ -0,0 +1,43 @@
+//===---------- RISC-V vdso configuration -------------------------* C++ *-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+#ifndef LLVM_LIBC_SRC___SUPPORT_OSUTIL_LINUX_RISCV_VDSO_H
+#define LLVM_LIBC_SRC___SUPPORT_OSUTIL_LINUX_RISCV_VDSO_H
+#include "src/__support/CPP/string_view.h"
+#include "src/__support/OSUtil/linux/vdso_sym.h"
+namespace LIBC_NAMESPACE_DECL {
+namespace vdso {
+// translate VDSOSym to symbol names
+// https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/riscv/kernel/vdso/vdso.lds.S
+LIBC_INLINE constexpr cpp::string_view symbol_name(VDSOSym sym) {
+  switch (sym) {
+  case VDSOSym::RTSigReturn:
+    return "__vdso_rt_sigreturn";
+  case VDSOSym::GetTimeOfDay:
+    return "__vdso_gettimeofday";
+  case VDSOSym::ClockGetTime:
+    return "__vdso_clock_gettime";
+  case VDSOSym::ClockGetRes:
+    return "__vdso_clock_getres";
+  case VDSOSym::GetCpu:
+    return "__vdso_getcpu";
+  case VDSOSym::FlushICache:
+    return "__vdso_flush_icache";
+  case VDSOSym::RiscvHwProbe:
+    return "__vdso_riscv_hwprobe";
+  default:
+    return "";
+  }
+}
+
+// symbol versions
+LIBC_INLINE constexpr cpp::string_view symbol_version(VDSOSym) {
+  return "LINUX_4.15";
+}
+} // namespace vdso
+} // namespace LIBC_NAMESPACE_DECL
+#endif // LLVM_LIBC_SRC___SUPPORT_OSUTIL_LINUX_RISCV_VDSO_H