605b51b84e
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
42 lines
1.3 KiB
C++
42 lines
1.3 KiB
C++
//===-- SingleStepCheck.h ------------------------------------- -*- C++ -*-===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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#ifndef liblldb_SingleStepCheck_H_
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#define liblldb_SingleStepCheck_H_
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namespace lldb_private
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{
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namespace process_linux
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{
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namespace impl
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{
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extern bool
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SingleStepWorkaroundNeeded();
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}
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// arm64 linux had a bug which prevented single-stepping and watchpoints from working on non-boot
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// cpus, due to them being incorrectly initialized after coming out of suspend. This issue is
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// particularly affecting android M, which uses suspend ("doze mode") quite aggressively. This
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// code detects that situation and makes single-stepping work by doing all the step operations on
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// the boot cpu.
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//
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// The underlying issue has been fixed in android N and linux 4.4. This code can be removed once
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// these systems become obsolete.
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inline bool
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SingleStepWorkaroundNeeded()
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{
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static bool value = impl::SingleStepWorkaroundNeeded();
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return value;
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}
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} // end namespace process_linux
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} // end namespace lldb_private
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#endif // #ifndef liblldb_SingleStepCheck_H_
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