adjust vDSO definitions

Author: Yifan Zhu

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

@@ -17,6 +17,7 @@ namespace vdso {
 #define LIBC_VDSO_HAS_CLOCK_GETRES
 
 // list of VDSO symbols
+// following the order in arch/arm64/kernel/vdso/vdso.lds.S
 enum class VDSOSym {
   RTSigReturn,
   GetTimeOfDay,

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

@@ -11,22 +11,34 @@
 namespace LIBC_NAMESPACE {
 namespace vdso {
 // macro definitions
-#define LIBC_VDSO_HAS_GETTIMEOFDAY
+// following the order in arch/arm/vdso/vdso.lds.S
 #define LIBC_VDSO_HAS_CLOCK_GETTIME
+#define LIBC_VDSO_HAS_GETTIMEOFDAY
+#define LIBC_VDSO_HAS_CLOCK_GETRES
+#define LIBC_VDSO_HAS_CLOCK_GETTIME64
 
 // list of VDSO symbols
 enum class VDSOSym {
-  GetTimeOfDay,
   ClockGetTime,
+  GetTimeOfDay,
+  ClockGetRes,
+  ClockGetTime64,
+  VDSOSymCount
 };
 
 // translate VDSOSym to symbol names
 LIBC_INLINE constexpr cpp::string_view symbol_name(VDSOSym sym) {
   switch (sym) {
-  case VDSOSym::GetTimeOfDay:
-    return "__vdso_gettimeofday";
   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 "";
   }
 }
 

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

@@ -11,12 +11,14 @@
 namespace LIBC_NAMESPACE {
 namespace vdso {
 // macro definitions
+// following the order in arch/riscv/kernel/vdso/vdso.lds.S
 #define LIBC_VDSO_HAS_RT_SIGRETURN
 #define LIBC_VDSO_HAS_GETTIMEOFDAY
 #define LIBC_VDSO_HAS_CLOCK_GETTIME
 #define LIBC_VDSO_HAS_CLOCK_GETRES
 #define LIBC_VDSO_HAS_GETCPU
 #define LIBC_VDSO_HAS_FLUSH_ICACHE
+#define LIBC_VDSO_HAS_RISCV_HWPROBE
 
 // list of VDSO symbols
 enum class VDSOSym {
@@ -26,6 +28,7 @@ enum class VDSOSym {
   ClockGetRes,
   GetCpu,
   FlushICache,
+  RiscvHwProbe,
   VDSOSymCount
 };
 
@@ -44,6 +47,8 @@ LIBC_INLINE constexpr cpp::string_view symbol_name(VDSOSym sym) {
     return "__vdso_getcpu";
   case VDSOSym::FlushICache:
     return "__vdso_flush_icache";
+  case VDSOSym::RiscvHwProbe:
+    return "__vdso_riscv_hwprobe";
   default:
     return "";
   }

libc/src/__support/OSUtil/linux/x86_64/vdso.h

@@ -11,25 +11,36 @@
 namespace LIBC_NAMESPACE {
 namespace vdso {
 // macro definitions
+// following the order in arch/x86/entry/vdso/vdso.lds.S
 #define LIBC_VDSO_HAS_CLOCK_GETTIME
-#define LIBC_VDSO_HAS_GETCPU
 #define LIBC_VDSO_HAS_GETTIMEOFDAY
+#define LIBC_VDSO_HAS_GETCPU
 #define LIBC_VDSO_HAS_TIME
+#define LIBC_VDSO_HAS_CLOCK_GETRES
 
 // list of VDSO symbols
-enum class VDSOSym { ClockGetTime, GetCpu, GetTimeOfDay, Time, VDSOSymCount };
+enum class VDSOSym {
+  ClockGetTime,
+  GetTimeOfDay,
+  GetCpu,
+  Time,
+  ClockGetRes,
+  VDSOSymCount
+};
 
 // translate VDSOSym to symbol names
 LIBC_INLINE constexpr cpp::string_view symbol_name(VDSOSym sym) {
   switch (sym) {
   case VDSOSym::ClockGetTime:
     return "__vdso_clock_gettime";
-  case VDSOSym::GetCpu:
-    return "__vdso_getcpu";
   case VDSOSym::GetTimeOfDay:
     return "__vdso_gettimeofday";
+  case VDSOSym::GetCpu:
+    return "__vdso_getcpu";
   case VDSOSym::Time:
     return "__vdso_time";
+  case VDSOSym::ClockGetRes:
+    return "__vdso_clock_getres";
   default:
     return "";
   }

libc/test/src/__support/OSUtil/linux/vdso_test.cpp

@@ -12,10 +12,16 @@
 
 namespace LIBC_NAMESPACE {
 TEST(LlvmLibcOSUtilVDSOTest, SymbolsDefined) {
-  // for now, we simply test all symbols are provided.
-  for (size_t i = 0; i < static_cast<size_t>(vdso::VDSOSym::VDSOSymCount); ++i)
+  for (size_t i = 0; i < static_cast<size_t>(vdso::VDSOSym::VDSOSymCount);
+       ++i) {
+    // RiscvHwProbe is provided only on >=6.4 kernels. Skip it for now.
+#ifdef LIBC_VDSO_HAS_RISCV_HWPROBE
+    if (static_cast<vdso::VDSOSym>(i) == vdso::VDSOSym::RiscvHwProbe)
+      continue;
+#endif
     EXPECT_NE(vdso::get_symbol(static_cast<vdso::VDSOSym>(i)),
               static_cast<void *>(nullptr));
+  }
 }
 
 #ifdef LIBC_VDSO_HAS_GETTIMEOFDAY