Summary:
//reviews.llvm.org/D33035 added in 2017 basic support for intel-pt. I
plan to improve it and use it to support reverse debugging.
I fixed a couple of issues and now this plugin works again:
1. pythonlib needed to be linked against it for the SB framework.
Linking was failing because of this
2. the decoding functionality was broken because it lacked handling for
instruction events. It seems old versions of libipt, the actual decoding
library, didn't require these, but modern version require it (you can
read more here
https://github.com/intel/libipt/blob/master/doc/howto_libipt.md). These
events signal overflows of the internal PT buffer in the CPU,
enable/disable events of tracing, async cpu events, interrupts, etc.
I ended up refactoring a little bit the code to reduce code duplication.
In another diff I'll implement some basic tests.
This is a simple execution of the library:
(lldb) target create "/data/users/wallace/rr-project/a.out"
Current executable set to '/data/users/wallace/rr-project/a.out' (x86_64).
(lldb) plugin load liblldbIntelFeatures.so
(lldb) b main
Breakpoint 1: where = a.out`main + 8 at test.cpp:10, address = 0x00000000004007fa
(lldb) b test.cpp:14
Breakpoint 2: where = a.out`main + 50 at test.cpp:14, address = 0x0000000000400824
(lldb) r
Process 902754 stopped
* thread #1, name = 'a.out', stop reason = breakpoint 1.1
frame #0: 0x00000000004007fa a.out`main at test.cpp:10
7 }
8
9 int main() {
-> 10 int z = 0;
11 for(int i = 0; i < 10000; i++)
12 z += fun(z);
13
Process 902754 launched: '/data/users/wallace/rr-project/a.out' (x86_64)
(lldb) processor-trace start all
(lldb) c
Process 902754 resuming
Process 902754 stopped
* thread #1, name = 'a.out', stop reason = breakpoint 2.1
frame #0: 0x0000000000400824 a.out`main at test.cpp:14
11 for(int i = 0; i < 10000; i++)
12 z += fun(z);
13
-> 14 cout << z<< endl;
15 return 0;
16 }
(lldb) processor-trace show-instr-log
thread #1: tid=902754
0x7ffff72299b9 <+9>: addq $0x8, %rsp
0x7ffff72299bd <+13>: retq
0x4007ed <+16>: addl $0x1, %eax
0x4007f0 <+19>: leave
0x4007f1 <+20>: retq
0x400814 <+34>: addl %eax, -0x4(%rbp)
0x400817 <+37>: addl $0x1, -0x8(%rbp)
0x40081b <+41>: cmpl $0x270f, -0x8(%rbp) ; imm = 0x270F
0x400822 <+48>: jle 0x40080a ; <+24> at test.cpp:12
0x400822 <+48>: jle 0x40080a ; <+24> at test.cpp:12
```
Subscribers: mgorny, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D76872
Summary:
r316368 broke this build when it introduced a reference to a pthread
function to the Utility module. This caused cmake to generate an
incorrect link line (wrong order of libs) because it did not see the
dependency from Utility to the system libraries. Instead these libraries
were being manually added to each final target.
This changes moves the dependency management from the individual targets
to the lldbUtility module, which is consistent with how llvm does it.
The final targets will pick up these libraries as they will be a part of
the link interface of the module.
Technically, some of these dependencies could go into the host module,
as that's where most of the os-specific code is, but I did not try to
investigate which ones.
Reviewers: zturner, sylvestre.ledru
Subscribers: lldb-commits, mgorny
Differential Revision: https://reviews.llvm.org/D39246
llvm-svn: 316997
Summary:
1. Provide single library for all Intel specific hardware features instead
of individual libraries for each feature
2. Added Intel(R) Processor Trace hardware feature in this single library.
Details about the tool implementing this feature is as follows:
Tool developed on top of LLDB to provide its users the execution
trace of the debugged inferiors. Tool's API are exposed as C++ object
oriented interface in a shared library. API are designed especially to be
easily integrable with IDEs providing LLDB as an application debugger.
Entire API is also available as Python functions through a script bridging
interface allowing development of python modules.
This patch also provides a CLI wrapper to use the Tool through LLDB's command
line. Highlights of the Tool and the wrapper are given below:
******************************
Intel(R) Processor Trace Tool:
******************************
- Provides execution trace of the debugged application
- Uses Intel(R) Processor Trace hardware feature (already implemented inside LLDB)
for this purpose
-- Collects trace packets generated by this feature from LLDB, decodes and
post-processes them
-- Constructs the execution trace of the application
-- Presents execution trace as a list of assembly instructions
- Provides 4 APIs (exposed as C++ object oriented interface)
-- start trace with configuration options for a thread/process,
-- stop trace for a thread/process,
-- get the execution flow (assembly instructions) for a thread,
-- get trace specific information for a thread
- Easily integrable into IDEs providing LLDB as application debugger
- Entire API available as Python functions through script bridging interface
-- Allows developing python apps on top of Tool
- README_TOOL.txt provides more details about the Tool, its dependencies, building
steps and API usage
- Tool ready to use through LLDB's command line
-- CLI wrapper has been developed on top of the Tool for this purpose
*********************************
CLI wrapper: cli-wrapper-pt.cpp
*********************************
- Provides 4 commands (syntax similar to LLDB's CLI commands):
-- processor-trace start
-- processor-trace stop
-- processor-trace show-trace-options
-- processor-trace show-instr-log
- README_CLI.txt provides more details about commands and their options
Signed-off-by: Abhishek Aggarwal <abhishek.a.aggarwal@intel.com>
Reviewers: clayborg, jingham, lldb-commits, labath
Reviewed By: clayborg
Subscribers: ravitheja, emaste, krytarowski, mgorny
Differential Revision: https://reviews.llvm.org/D33035
llvm-svn: 310261
Walter Erquinigo