[all-commits] [llvm/llvm-project] 31e44c: [trace] Use vector instead of ArrayRef when readin...

[walter erquinigo via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 31e44c01e3b5cc2cc7a9f1dc49806b3f050efb82
      https://github.com/llvm/llvm-project/commit/31e44c01e3b5cc2cc7a9f1dc49806b3f050efb82
  Author: Walter Erquinigo <wallace at fb.com>
  Date:   2022-03-21 (Mon, 21 Mar 2022)

  Changed paths:
    M lldb/include/lldb/Target/Trace.h
    M lldb/source/Target/Trace.cpp

  Log Message:
  -----------
  [trace] Use vector instead of ArrayRef when reading data

I incorrectly returned an ArrayRef when the underlying object didn't own
the data. Instead, returning a vector<uint8_t> is what we should do.

This fixes an issue when trying to access an intel-pt trace buffer
larger than 16 MB.

repro
```
go to a breakpoint
thread trace start -s 16777216
n
thread trace dump instructions # this doesn't fail anymore
```

Differential Revision: https://reviews.llvm.org/D122192


  Commit: a80c6c7d36d25999a28cfad32e1f461db95ba4dc
      https://github.com/llvm/llvm-project/commit/a80c6c7d36d25999a28cfad32e1f461db95ba4dc
  Author: Walter Erquinigo <wallace at fb.com>
  Date:   2022-03-21 (Mon, 21 Mar 2022)

  Changed paths:
    M lldb/source/Target/Target.cpp
    M lldb/test/API/commands/trace/TestTraceStartStop.py

  Log Message:
  -----------
  [trace] clear any existing tracing sessions before relaunching the binary

There's a bug caused when a process is relaunched: the target, which
doesn't change, keeps the Trace object from the previous process, which
is already defunct, and causes segmentation faults when it's attempted
to be used.
A fix is to clean up the Trace object when the target is disposing of
the previous process during relaunches.

A way to reproduce this:
```
lldb a.out
b main
r
process trace start
c
r
process trace start
```

Differential Revision: https://reviews.llvm.org/D122176


Compare: https://github.com/llvm/llvm-project/compare/f4b794427e80...a80c6c7d36d2