Kernel/aarch64: Implement Thread Local Storage

This commit adds Processor::set_thread_specific_data, and this function is used to factor out architecture specific implementation of setting the thread specific data. This function is implemented for aarch64 and x86_64, and the callsites are changed to use this function instead.
cubiclove · Feb 15, 2023 · cfd73e5 · cfd73e5
1 parent 7d0917f
commit cfd73e5
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Showing 6 changed files with 24 additions and 6 deletions.
diff --git a/Kernel/Arch/aarch64/ASM_wrapper.h b/Kernel/Arch/aarch64/ASM_wrapper.h
@@ -37,6 +37,11 @@ inline void set_sp_el1(FlatPtr sp_el1)
  asm("msr sp_el1, %[value]" ::[value] "r"(sp_el1));
 }
 
+inline void set_tpidr_el0(FlatPtr tpidr_el0)
+{
+ asm("msr tpidr_el0, %[value]" ::[value] "r"(tpidr_el0));
+}
+
 inline void flush()
 {
  asm("dsb ish");

diff --git a/Kernel/Arch/aarch64/Processor.cpp b/Kernel/Arch/aarch64/Processor.cpp
@@ -454,6 +454,8 @@ extern "C" void enter_thread_context(Thread* from_thread, Thread* to_thread)
 
  to_thread->set_cpu(Processor::current().id());
 
+ Processor::set_thread_specific_data(to_thread->thread_specific_data());
+
  auto in_critical = to_thread->saved_critical();
  VERIFY(in_critical > 0);
  Processor::restore_critical(in_critical);
@@ -466,4 +468,9 @@ StringView Processor::platform_string()
  return "aarch64"sv;
 }
 
+void Processor::set_thread_specific_data(VirtualAddress thread_specific_data)
+{
+ Aarch64::Asm::set_tpidr_el0(thread_specific_data.get());
+}
+
 }
diff --git a/Kernel/Arch/aarch64/Processor.h b/Kernel/Arch/aarch64/Processor.h
@@ -279,6 +279,8 @@ class Processor {
 
  static StringView platform_string();
 
+ static void set_thread_specific_data(VirtualAddress thread_specific_data);
+
 private:
  Processor(Processor const&) = delete;
 

diff --git a/Kernel/Arch/x86_64/Processor.cpp b/Kernel/Arch/x86_64/Processor.cpp
@@ -1543,8 +1543,7 @@ extern "C" void enter_thread_context(Thread* from_thread, Thread* to_thread)
  }
 
  auto& processor = Processor::current();
- MSR fs_base_msr(MSR_FS_BASE);
- fs_base_msr.set(to_thread->thread_specific_data().get());
+ Processor::set_thread_specific_data(to_thread->thread_specific_data());
 
  if (from_regs.cr3 != to_regs.cr3)
  write_cr3(to_regs.cr3);
@@ -1887,4 +1886,10 @@ UNMAP_AFTER_INIT void Processor::initialize_context_switching(Thread& initial_th
  VERIFY_NOT_REACHED();
 }
 
+void Processor::set_thread_specific_data(VirtualAddress thread_specific_data)
+{
+ MSR fs_base_msr(MSR_FS_BASE);
+ fs_base_msr.set(thread_specific_data.get());
+}
+
 }
diff --git a/Kernel/Arch/x86_64/Processor.h b/Kernel/Arch/x86_64/Processor.h
@@ -419,6 +419,8 @@ class Processor {
  static ErrorOr<Vector<FlatPtr, 32>> capture_stack_trace(Thread& thread, size_t max_frames = 0);
 
  static StringView platform_string();
+
+ static void set_thread_specific_data(VirtualAddress thread_specific_data);
 };
 
 }
diff --git a/Kernel/Syscalls/mmap.cpp b/Kernel/Syscalls/mmap.cpp
@@ -566,10 +566,7 @@ ErrorOr<FlatPtr> Process::sys$allocate_tls(Userspace<char const*> initial_data,
 
  TRY(main_thread->make_thread_specific_region({}));
 
-#if ARCH(X86_64)
- MSR fs_base_msr(MSR_FS_BASE);
- fs_base_msr.set(main_thread->thread_specific_data().get());
-#endif
+ Processor::set_thread_specific_data(main_thread->thread_specific_data());
 
  return m_master_tls_region.unsafe_ptr()->vaddr().get();
  });