Work around a stepping bug in arm64 android M

Summary:
On arm64, linux<=4.4 and Android<=M there is a bug, which prevents single-stepping from working when
the system comes back from suspend, because of incorrectly initialized CPUs. This did not really
affect Android<M, because it did not use software suspend, but it is a problem for M, which uses
suspend (doze) quite extensively.  Fortunately, it seems that the first CPU is not affected by
this bug, so this commit implements a workaround by forcing the inferior to execute on the first
cpu whenever we are doing single stepping.

While inside, I have moved the implementations of Resume() and SingleStep() to the thread class
(instead of process).

Reviewers: tberghammer, ovyalov

Subscribers: aemerson, rengolin, tberghammer, danalbert, srhines, lldb-commits

Differential Revision: http://reviews.llvm.org/D17509

llvm-svn: 261636

1 files changed, 3 insertions, 13 deletions

diff --git a/lldb/source/Plugins/Process/Linux/NativeProcessLinux.h b/lldb/source/Plugins/Process/Linux/NativeProcessLinux.h
index 7bac1dc..c4c4a4a 100644
--- a/lldb/source/Plugins/Process/Linux/NativeProcessLinux.h
+++ b/lldb/source/Plugins/Process/Linux/NativeProcessLinux.h
@@ -127,6 +127,9 @@ namespace process_linux {
                       size_t data_size = 0,
                       long *result = nullptr);
 
+        bool
+        SupportHardwareSingleStepping() const;
+
     protected:
         // ---------------------------------------------------------------------
         // NativeProcessProtocol protected interface
@@ -239,9 +242,6 @@ namespace process_linux {
         void
         MonitorSignal(const siginfo_t &info, NativeThreadLinux &thread, bool exited);
 
-        bool
-        SupportHardwareSingleStepping() const;
-
         Error
         SetupSoftwareSingleStepping(NativeThreadLinux &thread);
 
@@ -285,16 +285,6 @@ namespace process_linux {
         Error
         GetEventMessage(lldb::tid_t tid, unsigned long *message);
 
-        /// Resumes the given thread.  If @p signo is anything but
-        /// LLDB_INVALID_SIGNAL_NUMBER, deliver that signal to the thread.
-        Error
-        Resume(lldb::tid_t tid, uint32_t signo);
-
-        /// Single steps the given thread.  If @p signo is anything but
-        /// LLDB_INVALID_SIGNAL_NUMBER, deliver that signal to the thread.
-        Error
-        SingleStep(lldb::tid_t tid, uint32_t signo);
-
         void
         NotifyThreadDeath (lldb::tid_t tid);