linux-toradex.git/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c, branch v4.9.108

perf intel-pt: Fix timestamp following overflow

2018-04-20T06:20:41+00:00

commit 91d29b288aed3406caf7c454bf2b898c96cfd177 upstream.

timestamp_insn_cnt is used to estimate the timestamp based on the number of
instructions since the last known timestamp.

If the estimate is not accurate enough decoding might not be correctly
synchronized with side-band events causing more trace errors.

However there are always timestamps following an overflow, so the
estimate is not needed and can indeed result in more errors.

Suppress the estimate by setting timestamp_insn_cnt to zero.

Signed-off-by: Adrian Hunter 
Cc: Jiri Olsa 
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1520431349-30689-5-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf intel-pt: Fix error recovery from missing TIP packet

2018-04-20T06:20:41+00:00

commit 1c196a6c771c47a2faa63d38d913e03284f73a16 upstream.

When a TIP packet is expected but there is a different packet, it is an
error. However the unexpected packet might be something important like a
TSC packet, so after the error, it is necessary to continue from there,
rather than the next packet. That is achieved by setting pkt_step to
zero.

Signed-off-by: Adrian Hunter 
Cc: Jiri Olsa 
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1520431349-30689-4-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf intel-pt: Fix overlap detection to identify consecutive buffers correctly

2018-04-20T06:20:41+00:00

commit 117db4b27bf08dba412faf3924ba55fe970c57b8 upstream.

Overlap detection was not not updating the buffer's 'consecutive' flag.
Marking buffers consecutive has the advantage that decoding begins from
the start of the buffer instead of the first PSB. Fix overlap detection
to identify consecutive buffers correctly.

Signed-off-by: Adrian Hunter 
Cc: Jiri Olsa 
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1520431349-30689-2-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf intel-pt: Clear FUP flag on error

2017-07-27T22:07:58+00:00

commit 6a558f12dbe85437acbdec5e149ea07b5554eced upstream.

Sometimes a FUP packet is associated with a TSX transaction and a flag is
set to indicate that. Ensure that flag is cleared on any error condition
because at that point the decoder can no longer assume it is correct.

Signed-off-by: Adrian Hunter 
Cc: Andi Kleen 
Link: http://lkml.kernel.org/r/1495786658-18063-9-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf intel-pt: Use FUP always when scanning for an IP

2017-07-27T22:07:57+00:00

commit 622b7a47b843c78626f40c1d1aeef8483383fba2 upstream.

The decoder will try to use branch packets to find an IP to start decoding
or to recover from errors. Currently the FUP packet is used only in the
case of an overflow, however there is no reason for that to be a special
case. So just use FUP always when scanning for an IP.

Signed-off-by: Adrian Hunter 
Cc: Andi Kleen 
Link: http://lkml.kernel.org/r/1495786658-18063-8-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf intel-pt: Ensure never to set 'last_ip' when packet 'count' is zero

2017-07-27T22:07:57+00:00

commit f952eaceb089b691eba7c4e13686e742a8f26bf5 upstream.

Intel PT uses IP compression based on the last IP. For decoding purposes,
'last IP' is not updated when a branch target has been suppressed, which is
indicated by IPBytes == 0. IPBytes is stored in the packet 'count', so
ensure never to set 'last_ip' when packet 'count' is zero.

Signed-off-by: Adrian Hunter 
Cc: Andi Kleen 
Link: http://lkml.kernel.org/r/1495786658-18063-7-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf intel-pt: Fix last_ip usage

2017-07-27T22:07:57+00:00

commit ee14ac0ef6827cd6f9a572cc83dd0191ea17812c upstream.

Intel PT uses IP compression based on the last IP. For decoding
purposes, 'last IP' is considered to be reset to zero whenever there is
a synchronization packet (PSB). The decoder wasn't doing that, and was
treating the zero value to mean that there was no last IP, whereas
compression can be done against the zero value. Fix by setting last_ip
to zero when a PSB is received and keep track of have_last_ip.

Signed-off-by: Adrian Hunter 
Cc: Andi Kleen 
Link: http://lkml.kernel.org/r/1495786658-18063-6-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf intel-pt: Ensure IP is zero when state is INTEL_PT_STATE_NO_IP

2017-07-27T22:07:57+00:00

commit ad7167a8cd174ba7d8c0d0ed8d8410521206d104 upstream.

A value of zero is used to indicate that there is no IP. Ensure the
value is zero when the state is INTEL_PT_STATE_NO_IP.

Signed-off-by: Adrian Hunter 
Cc: Andi Kleen 
Link: http://lkml.kernel.org/r/1495786658-18063-5-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf intel-pt: Fix missing stack clear

2017-07-27T22:07:57+00:00

commit 12b7080609097753fd8198cc1daf589be3ec1cca upstream.

The return compression stack must be cleared whenever there is a PSB. Fix
one case where that was not happening.

Signed-off-by: Adrian Hunter 
Cc: Andi Kleen 
Link: http://lkml.kernel.org/r/1495786658-18063-4-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf intel-pt: Improve sample timestamp

2017-07-27T22:07:57+00:00

commit 3f04d98e972b59706bd43d6cc75efac91f8fba50 upstream.

The decoder uses its current timestamp in samples. Usually that is a
timestamp that has already passed, but in some cases it is a timestamp
for a branch that the decoder is walking towards, and consequently
hasn't reached. Improve that situation by using the pkt_state to
determine when to use the current or previous timestamp.

Signed-off-by: Adrian Hunter 
Cc: Andi Kleen 
Link: http://lkml.kernel.org/r/1495786658-18063-3-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman