[BOLT] Enable hugify for AArch64 (llvm#117158)

Add required hugify instrumentation and runtime libraries support for AArch64.
Fixes llvm#58226
Unblocks llvm#62695

Author: alekuz01

bolt/CMakeLists.txt

@@ -136,7 +136,7 @@ if (LLVM_INCLUDE_TESTS)
 endif()
 
 if (BOLT_ENABLE_RUNTIME)
-  message(STATUS "Building BOLT runtime libraries for X86")
+  message(STATUS "Building BOLT runtime libraries for ${CMAKE_SYSTEM_PROCESSOR}")
   set(extra_args "")
   if(CMAKE_SYSROOT)
     list(APPEND extra_args -DCMAKE_SYSROOT=${CMAKE_SYSROOT})

bolt/lib/Rewrite/RewriteInstance.cpp

@@ -597,8 +597,9 @@ Error RewriteInstance::discoverStorage() {
 
   // Hugify: Additional huge page from left side due to
   // weird ASLR mapping addresses (4KB aligned)
-  if (opts::Hugify && !BC->HasFixedLoadAddress)
+  if (opts::Hugify && !BC->HasFixedLoadAddress) {
     NextAvailableAddress += BC->PageAlign;
+  }
 
   if (!opts::UseGnuStack && !BC->IsLinuxKernel) {
     // This is where the black magic happens. Creating PHDR table in a segment
@@ -5885,17 +5886,28 @@ void RewriteInstance::rewriteFile() {
 
   // Write all allocatable sections - reloc-mode text is written here as well
   for (BinarySection &Section : BC->allocatableSections()) {
-    if (!Section.isFinalized() || !Section.getOutputData())
+    if (!Section.isFinalized() || !Section.getOutputData()) {
+      LLVM_DEBUG(if (opts::Verbosity > 1) {
+        dbgs() << "BOLT-INFO: new section is finalized or !getOutputData, skip "
+               << Section.getName() << '\n';
+      });
       continue;
-    if (Section.isLinkOnly())
+    }
+    if (Section.isLinkOnly()) {
+      LLVM_DEBUG(if (opts::Verbosity > 1) {
+        dbgs() << "BOLT-INFO: new section is link only, skip "
+               << Section.getName() << '\n';
+      });
       continue;
+    }
 
     if (opts::Verbosity >= 1)
       BC->outs() << "BOLT: writing new section " << Section.getName()
                  << "\n data at 0x"
                  << Twine::utohexstr(Section.getAllocAddress()) << "\n of size "
                  << Section.getOutputSize() << "\n at offset "
-                 << Section.getOutputFileOffset() << '\n';
+                 << Section.getOutputFileOffset() << " with content size "
+                 << Section.getOutputContents().size() << '\n';
     OS.seek(Section.getOutputFileOffset());
     Section.write(OS);
   }

bolt/runtime/common.h

@@ -151,10 +151,12 @@ struct timespec {
   uint64_t tv_nsec; /* nanoseconds */
 };
 
-#if defined(__aarch64__)
+#if defined(__aarch64__) || defined(__arm64__)
 #include "sys_aarch64.h"
-#else
+#elif defined(__x86_64__)
 #include "sys_x86_64.h"
+#else
+#error "For AArch64/ARM64 and X86_64 only."
 #endif
 
 constexpr uint32_t BufSize = 10240;

bolt/runtime/hugify.cpp

@@ -6,7 +6,8 @@
 //
 //===---------------------------------------------------------------------===//
 
-#if defined (__x86_64__) && !defined(__APPLE__)
+#if defined(__x86_64__) ||                                                     \
+    (defined(__aarch64__) || defined(__arm64__)) && !defined(__APPLE__)
 
 #include "common.h"
 
@@ -73,8 +74,10 @@ static bool hasPagecacheTHPSupport() {
   if (Res < 0)
     return false;
 
-  if (!strStr(Buf, "[always]") && !strStr(Buf, "[madvise]"))
+  if (!strStr(Buf, "[always]") && !strStr(Buf, "[madvise]")) {
+    DEBUG(report("[hugify] THP support is not enabled.\n");)
     return false;
+  }
 
   struct KernelVersionTy {
     uint32_t major;
@@ -167,12 +170,20 @@ extern "C" void __bolt_hugify_self_impl() {
 
 /// This is hooking ELF's entry, it needs to save all machine state.
 extern "C" __attribute((naked)) void __bolt_hugify_self() {
+  // clang-format off
 #if defined(__x86_64__)
   __asm__ __volatile__(SAVE_ALL "call __bolt_hugify_self_impl\n" RESTORE_ALL
-                                "jmp __bolt_hugify_start_program\n" ::
-                                    :);
+                                "jmp __bolt_hugify_start_program\n"
+                                :::);
+#elif defined(__aarch64__) || defined(__arm64__)
+  __asm__ __volatile__(SAVE_ALL "bl __bolt_hugify_self_impl\n" RESTORE_ALL
+                                "adrp x16, __bolt_hugify_start_program\n"
+                                "add x16, x16, #:lo12:__bolt_hugify_start_program\n"
+                                "br x16\n"
+                                :::);
 #else
-  exit(1);
+  __exit(1);
 #endif
+  // clang-format on
 }
 #endif

bolt/test/runtime/X86/Inputs/user_func_order.txt renamed to bolt/test/runtime/Inputs/user_func_order.txt

@@ -11,17 +11,28 @@ int main(int argc, char **argv) {
 REQUIRES: system-linux,bolt-runtime
 
 RUN: %clang %cflags -no-pie %s -o %t.nopie.exe -Wl,-q
-RUN: %clang %cflags -fpic -pie %s -o %t.pie.exe -Wl,-q
+RUN: %clang %cflags -fpic %s -o %t.pie.exe -Wl,-q
 
 RUN: llvm-bolt %t.nopie.exe --lite=0 -o %t.nopie --hugify
 RUN: llvm-bolt %t.pie.exe --lite=0 -o %t.pie --hugify
 
+RUN: llvm-nm --numeric-sort --print-armap %t.nopie | \
+RUN:   FileCheck %s -check-prefix=CHECK-NM
 RUN: %t.nopie | FileCheck %s -check-prefix=CHECK-NOPIE
 
-CHECK-NOPIE: Hello world
-
+RUN: llvm-nm --numeric-sort --print-armap %t.pie | \
+RUN:   FileCheck %s -check-prefix=CHECK-NM
 RUN: %t.pie | FileCheck %s -check-prefix=CHECK-PIE
 
+CHECK-NM:       W  __hot_start
+CHECK-NM-NEXT:  T _start
+CHECK-NM:       T main
+CHECK-NM:       W __hot_end
+CHECK-NM:       t __bolt_hugify_start_program
+CHECK-NM-NEXT:  W __bolt_runtime_start
+
+CHECK-NOPIE: Hello world
+
 CHECK-PIE: Hello world
 
 */

bolt/test/runtime/X86/hugify.c renamed to bolt/test/runtime/hugify.c

@@ -5,19 +5,15 @@
  */
 #include <stdio.h>
 
-int foo(int x) {
-  return x + 1;
-}
+int foo(int x) { return x + 1; }
 
 int fib(int x) {
   if (x < 2)
     return x;
   return fib(x - 1) + fib(x - 2);
 }
 
-int bar(int x) {
-  return x - 1;
-}
+int bar(int x) { return x - 1; }
 
 int main(int argc, char **argv) {
   printf("fib(%d) = %d\n", argc, fib(argc));
@@ -31,14 +27,28 @@ RUN: %clang %cflags -no-pie %s -o %t.exe -Wl,-q
 
 RUN: llvm-bolt %t.exe --relocs=1 --lite --reorder-functions=user \
 RUN:   --hugify --function-order=%p/Inputs/user_func_order.txt -o %t
+RUN: llvm-bolt %t.exe --relocs=1 --lite --reorder-functions=user \
+RUN:   --function-order=%p/Inputs/user_func_order.txt -o %t.nohugify
 RUN: llvm-nm --numeric-sort --print-armap %t | \
 RUN:   FileCheck %s -check-prefix=CHECK-NM
 RUN: %t 1 2 3 | FileCheck %s -check-prefix=CHECK-OUTPUT
+RUN: llvm-nm --numeric-sort --print-armap %t.nohugify | \
+RUN:   FileCheck %s -check-prefix=CHECK-NM-NOHUGIFY
+RUN: %t.nohugify 1 2 3 | FileCheck %s -check-prefix=CHECK-OUTPUT-NOHUGIFY
+
 
 CHECK-NM:      W  __hot_start
 CHECK-NM:      T main
 CHECK-NM-NEXT: T fib
 CHECK-NM-NEXT: W __hot_end
+CHECK-NM: t __bolt_hugify_start_program
+CHECK-NM-NEXT: W __bolt_runtime_start
+
+CHECK-NM-NOHUGIFY:      W  __hot_start
+CHECK-NM-NOHUGIFY:      T main
+CHECK-NM-NOHUGIFY-NEXT: T fib
+CHECK-NM-NOHUGIFY-NEXT: W __hot_end
 
 CHECK-OUTPUT: fib(4) = 3
+CHECK-OUTPUT-NOHUGIFY: fib(4) = 3
 */