This change implements what the source-code comment already promised but
didn't keep: As we only record time deltas instead of absolute time values,
prevtime must not be overwritten unless the current delta was really added
to the trace. This has caused timing information to be stored incorrectly
if certain events were skipped (e.g., because they didn't match the memory
map configured by the user).
Change-Id: Id40271d117dd91b1122136c62329d64174f304b0
Richard noticed that instr2 values are off by one when done with the
MemoryImporter vs. with his own importer. The core problem is that
the dynamic instruction counter in the Importer base class
(Importer::copy_to_database, instruction_count_t instr) gets increased
*after* reporting an IP event to the importer implementation; this has
the side-effect that memory access events have a +1 dynamic
instruction count offset with regard to the IP event of the
instruction they belong to.
Bottom line: IP events and all memory events belonging to that
instruction should have the same dynamic instruction number.
Christian argued for the numbers starting with 0, which, as a side
effect, relativizes the repercussions of the change introduced in the
previous commit, as the new "first" event gets the sequence number 0
now.
- All experiments and importers only dealing with memory accesses
(MemoryImporter) are affected by this change: The dynamic
instruction count now starts with 0 instead of 1. Together with
the previous commit, the only change is one additional dynamic
instruction at position 0. Note that existing trace files do not
have this additional instruction, which shifts all trace positions
by 1.
- All importers that process *only* IP events (InstructionImporter,
RandomJumpImporter, RegisterImporter) won't see any difference.
Commit 036e340, though, introduced a +1 offset.
- Experiments that use these instruction counts for navigating to
the target instruction must be checked to properly deal with the
dynamic instruction #0 (no forwarding necessary). All dynamic
instruction offsetting should now work uniformly for both memory
accesses and all other fault models. To be sure everything works
in order, sanity-check the current absolute instruction pointer
right before fault injection.
Change-Id: I3f509f1b47836fa78fd029a7bb7c36c878912d97
When starting the tracing plugin (simulator.addFlow()), at the moment
the *current* dynamic instruction (e.g., the one the start symbol
points to) is skipped, and tracing commences with the second
instruction. This change records an additional instruction event at
the trace begin.
Note that this change affects all tracing-plugin users. The first
event gets recorded when starting the plugin (simulator.addFlow()).
This avoids compatibility/off-by-one issues when recording traces with
the generic-tracing experiment vs. with custom experiments.
Change-Id: Ic24e17a68b8a44edad3be994e9edd6d6712bfda1
This reverts commit 036e340bd9.
Problems with this one were:
- Broken event timings. m_prevtime wasn't reset to m_curtime in
TracingPlugin::handleSingleIP(), resulting in a large deltatime
being recorded for the second event, too. This effectively
doubled the experiment's start time.
- Code repetition (copy/pasted for special handling of first event),
making planned changes (advanced tracing for IP events) more
difficult.
- Unnecessary additional tracing-plugin interface method.
Change-Id: I4b74d1a3f4563aabe6626399f9b30a2171b4c285
When using the generic-tracing experiment for generating a trace, the
first event, after the tracing is started (the start-symbol) is lost
in the trace. This patch handles this special case seperately.
Change-Id: Ia131a8559d67161532504160826fdb100247ed75
Call this script from a build directory to setup
a build environment for FailBochs pruning.
Usage:
<path to fail>/configurations/x86_pruning.sh <Experiment name>
Change-Id: I778a20c258dcd5349c3da9e1c5a8542af43f61d5
* Fowler's Law of Refactoring: Have test cases available.
* BjoernD's Corollary to Fowler's Law: Use these tests!
Change-Id: I3d3e48ffe08209891c6204655323cd26a0eaaebd
The experiment does support
- 1 bit faults in registers/memory/IP
- 2 bit faults in registers (all)
- n bit faults monte-carlo in registers
Change-Id: Ifdd7df6ec4bc88cfc75391b5e19e0d648fd0d087
The RegisterImporter splits each register into 1 byte chunks. The
--do-not-split flag prohibits this splitting. Be aware, that def/use
pruning won't work correctly in mixed-width cases (EAX/AX/AH/AL).
Change-Id: Ifa1930bdd9f317a6fd3ae50c4ff3cffc97504640
During the prune step the data_width of the injected location was not
propagated before. It is now stored in fsppilot (database layout change!) and
sent in the fsppilot protobuf message.
Change-Id: I0562f6fc8957adea0f8a9fb63469ca5e3f4b7b2d
There's one fspgroup entry for every trace entry, the pilot_id is
therefore *not* part of the (unique) primary key. If this had been
right in the first place, it would have revealed an equivalence-based
fault-space pruning bug early ... :-/
Change-Id: I449d4985645c6631c0a8db0c64510364677b1354
If you only need raw failure counts, no-effect write equivalence classes
are redundant and only slow down access to the trace and fspgroup tables.
This switch prevents any accesstype='W' entries from finding their way into
the trace table.
Change-Id: Ifb415994063a2107769bc80ebd2fd780de5a4dda
Initially this was implemented by directly passing through trace
events to the MemoryImporter, keeping a record of conditional jumps
and opcodes, and UPDATEing all inserted rows in a second pass when the
MemoryImporter is finished.
Unfortunately, UPDATE is very slow, and keeping all information in
memory till the end doesn't scale indefinitely. Therefore the
implementation now delays passing memory access events upwards to the
MemoryImporter only until enough branch history is aggregated, and
taps into Importer's database operations with a set of new virtual
functions that are called downwards.
Change-Id: I159b2533932087087fb3049f4ff07a5f17a25a00
A MemoryImporter that additionally imports Relyzer-style conditional
branch history, instruction opcodes, and a virtual
duration=time2-time1+1 column (MariaDB 5.2+ only) for fault-space
pruning purposes.
Change-Id: I6764a26fa8aae21655be44134b88fdee85e67ff6
This change touches several subsystems, tools and experiments
(sal, util, cmake, import-trace, generic-tracing, nanojpeg), and
changes details not worth separate commits.
Change-Id: Icd1d664d1be5cfc2212dbf77801c271183214d08
This tool can now import extended trace information with the
--extended-trace command-line parameter. The existing importers cease
using artificial access_info_t objects in favor of passing through the
original Trace_Event wherever possible. This allows us to import
extended trace information for all importers.
Change-Id: I3613e9d05d5e69ad49e96f4dc5ba0b1c4ef95a11
It's OK if we cannot map every register LLVM knows to a Fail register
ID, but we need to explicitly skip these cases in the
RegisterImporter.
Change-Id: I2152f819fb94aa4de5720c5798b229b66988d382
The input (taken on stdin) is a gem5.opt --debug-flags=MemoryAccess
trace (--format gem5), or a dump-trace output (--format dump) for easy
trace synthesis (for testing purposes).
gem5 format: Currently imports physical, not virtual memory addresses.
dump format: Currently ignores extended trace information.
Change-Id: Ic26a996d6fb9ce4175c855fadcbcff9ac9263888
This change became necessary as we observed weird fail-client SIGSEGV
crashes with both Bochs and Gem5 backends and different experiments.
Some Fail* components are instantiated statically: the
SimulatorController instance "simulator", containing the
ListenerManager and the CoroutineManager, and the active
ExperimentFlow subclass(es)
(experiments/instantiate-experiment*.ah.in). The experiment(s) is
registered as an active flow in the CoroutineManager at startup.
As plugins (which are ExperimentFlows themselves) are often created on
an experiment's stack, ExperimentFlows deregister themselves on
destruction (e.g., when leaving the plugin variable's scope). The
core problem is, that the creation and destruction order of statically
instantiated objects depends on the link order; if the experiment is
destroyed after the CoroutineManager, its automatic self-deregistering
feature talks to the smoking ruins of the latter.
This change removes all static instantiations of ExperimentFlow and
replaces them with constructions on the heap. Additionally it makes
sure that the CoroutineManager recognizes that a shutdown is in
progress, and refrains from touching potentially already destroyed
data structures when a (mistakenly globally instantiated)
ExperimentFlow deregisters in this case.
Change-Id: I8a7d42fb141222cd2cce6040ab1a01f9de61be24
Contemporary AspectC++ versions can deal with the LLVM headers very
well, and #ifdef __puma stuff in Fail* headers results in
unmaintainable #ifdef __puma blocks in other parts of Fail* (e.g., the
trace importer).
Make sure you're using a 64-bit ac++ when living in a 64-bit userland
(the 32-bit version doesn't know about __int128), and be aware that
AspectC++ r325 introduced a regression that has not been fixed yet.
Change-Id: I5bb759b08995a74b020d44a2b40e9d7a6e18111c
