This is the mail archive of the mailing list for the GDB project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: Could not use "record btrace" even if I have Intel PT hardware feature

My best regards to you.

     No System Is Safe!
     Dongliang Mu

2016-09-06 10:59 GMT-04:00 Metzger, Markus T <>:
>> -----Original Message-----
>> From: [] On
>> Behalf Of ???
>> Sent: Tuesday, September 6, 2016 4:37 PM
>> To:
>> Subject: Could not use "record btrace" even if I have Intel PT hardware feature
> Hello Dongliang,
>> I encounter one problem when I try to leverage Intel PT to do branch tracing.
>> My cpu has Intel PT feature via "grep intel_pt /proc/cpuinfo".
>> $ grep intel_pt /proc/cpuinfo
>> flags : ...intel_pt...
>> $ gdb simple
>> .......
>> (gdb) b main
>> Breakpoint 1 at 0x40050c
>> (gdb) r
>> Starting program: .../Work/Projects/simple
>> Breakpoint 1, 0x000000000040050c in main ()
>> (gdb) record btrace
>> Target does not support branch tracing.
>> (gdb) record btrace pt
>> GDB does not support Intel Processor Trace.
> You need a kernel that supports it (4.1+) and you need a GDB that supports it.

I am using Debian Testing with linux kernel 4.6.0-1 and gdb 7.11.1-2

> Newer Linux distributions should already provide GDB with Intel PT support.  If
> your distribution doesn't or if you want to build GDB yourself, please configure
> it with "--with-intel-pt".

I have installed libipt-dev and libipt1 packages.

> If your Linux distribution does not provide libipt(-devel), you may need to
> build it yourself.  You can get the sources from here:
> You may also need to configure GDB with "--with-libipt-prefix=<path-to-libipt>"
> if you don't (want to) install libipt in a standard place.
> You may further need to install kernel headers - GDB needs
> /usr/include/linux/perf_event.h.

And I have checked the existence of /usr/include/linux/perf_event.h.

Should I reboot my Debian to make kernel module for Intel PT effective?

> Regards,
> Markus.
> Intel Deutschland GmbH
> Registered Address: Am Campeon 10-12, 85579 Neubiberg, Germany
> Tel: +49 89 99 8853-0,
> Managing Directors: Christin Eisenschmid, Christian Lamprechter
> Chairperson of the Supervisory Board: Nicole Lau
> Registered Office: Munich
> Commercial Register: Amtsgericht Muenchen HRB 186928

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]