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9992c2d50a
linux/tools/perf
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Adrian Hunter 9992c2d50a perf intel-pt: Fix potential loop forever 
TSC packets contain only 7 bytes of TSC.  The 8th byte is assumed to
change so infrequently that its value can be inferred.  However the
logic must cater for a 7 byte wraparound, which it does by adding 1 to
the top byte.

The existing code was doing that with a while loop even though the
addition should only need to be done once.  That logic won't work (will
loop forever) if TSC wraps around at the 8th byte.  Theoretically that
would take at least 10 years, unless something else went wrong.

And what else could go wrong.  Well, if the chunks of trace data are
processed out of order, it will make it look like the 7-byte TSC has
gone backwards (i.e. wrapped).  If that happens 256 times then stuck in
the while loop it will be.

Fix that by getting rid of the unnecessary while loop.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1443186956-18718-4-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-09-28 16:44:31 -03:00
..
arch perf tools: Introduce regs_query_register_offset() for x86 2015-09-15 09:48:33 -03:00
bench perf bench futex: Add lock_pi stresser 2015-07-20 17:49:51 -03:00
config Merge branch 'perf/urgent' into perf/core, to pick up fixes before applying new changes 2015-09-18 09:24:01 +02:00
Documentation perf auxtrace: Fix 'instructions' period of zero 2015-09-28 15:50:56 -03:00
python perf python: Make twatch.py use soft dummy event, freq=0 2015-07-29 10:51:45 -03:00
scripts perf scripts python: Add new compaction-times script 2015-08-28 14:53:40 -03:00
tests Merge branch 'perf/urgent' into perf/core, to resolve a conflict 2015-09-16 09:19:56 +02:00
trace/strace/groups perf trace: Add read/write to the file group 2015-09-04 13:22:06 -03:00
ui perf hists browser: Use the map to determine if a DSO is being used as a kernel 2015-09-28 15:50:54 -03:00
util perf intel-pt: Fix potential loop forever 2015-09-28 16:44:31 -03:00
.gitignore perf tools: Add Intel PT instruction decoder 2015-08-17 11:11:36 -03:00
Build perf trace: Support 'strace' syscall event groups 2015-07-20 15:16:32 -03:00
builtin-annotate.c perf env: Rename some leftovers from rename to perf_env 2015-09-14 12:50:20 -03:00
builtin-bench.c perf bench futex: Add lock_pi stresser 2015-07-20 17:49:51 -03:00
builtin-buildid-cache.c perf buildid: Introduce sysfs/filename__sprintf_build_id 2015-08-28 14:53:50 -03:00
builtin-buildid-list.c perf buildid: Introduce sysfs/filename__sprintf_build_id 2015-08-28 14:53:50 -03:00
builtin-data.c perf data: Support using -f to override perf.data file ownership for 'convert' 2015-04-02 13:18:52 -03:00
builtin-diff.c perf callchain: Allow disabling call graphs per event 2015-08-12 13:20:28 -03:00
builtin-evlist.c perf evlist: Support using -f to override perf.data file ownership 2015-04-02 13:18:45 -03:00
builtin-help.c perf tools: Add the bash completion for listing subsubcommands of perf help 2015-03-19 13:49:39 -03:00
builtin-inject.c perf tools: Add new PERF_RECORD_SWITCH event 2015-07-23 22:51:13 -03:00
builtin-kmem.c perf kmem: Fill in the missing session freeing after an error occurs 2015-07-01 17:53:49 -03:00
builtin-kvm.c tools lib api fs: Replace debugfs/tracefs objects interface with fs.c 2015-09-14 12:50:15 -03:00
builtin-list.c perf list: Extend raw-dump to certain kind of events 2015-02-27 15:52:24 -03:00
builtin-lock.c perf machine: Protect the machine->threads with a rwlock 2015-05-08 16:19:27 -03:00
builtin-mem.c perf mem: Fill in the missing session freeing after an error occurs 2015-07-01 17:53:49 -03:00
builtin-probe.c perf probe: Fix a segfault when removing uprobe events 2015-09-21 18:01:17 -03:00
builtin-record.c perf record: Synthesize COMM event for a command line workload 2015-09-22 22:43:12 -03:00
builtin-report.c perf report: Fix sample type validation for synthesized callchains 2015-09-28 16:42:38 -03:00
builtin-sched.c perf sched: Add option to merge like comms to lat output 2015-05-27 12:21:45 -03:00
builtin-script.c perf tools: Fix use of wrong event when processing exit events 2015-09-02 17:46:26 -03:00
builtin-stat.c perf stat: Quieten failed to read counter message 2015-09-02 16:30:47 -03:00
builtin-timechart.c perf tools: Elliminate alignment holes 2015-05-18 10:17:33 -03:00
builtin-top.c perf top: Filter symbols based on __map__is_kernel(map) 2015-09-28 15:50:53 -03:00
builtin-trace.c perf evsel: Propagate error info from tp_format 2015-09-15 09:48:33 -03:00
builtin.h perf tools: Add new 'perf data' command 2015-02-25 12:42:25 -03:00
command-list.txt perf tools: Add new 'perf data' command 2015-02-25 12:42:25 -03:00
CREDITS
design.txt perf tools: Update some code references in design.txt 2014-03-18 18:17:06 -03:00
Makefile perf build: Fix single target build dependency check 2015-06-22 11:27:09 -03:00
Makefile.perf tools build: Build fixdep helper from perf and basic libs 2015-09-28 15:50:55 -03:00
MANIFEST perf tools: Add include/err.h into MANIFEST 2015-09-22 10:47:05 -03:00
perf-archive.sh
perf-completion.sh perf tools: Avoid confusion with preloaded bash function for perf bash completion 2015-03-19 13:53:27 -03:00
perf-read-vdso.c perf tools: Build programs to copy 32-bit compatibility 2014-10-29 10:32:48 -02:00
perf-sys.h perf tools: Move generic barriers out of perf-sys.h 2015-05-08 16:05:08 -03:00
perf-with-kcore.sh perf tools: Fix perf-with-kcore handling of arguments containing spaces 2015-08-06 16:48:27 -03:00
perf.c perf env: Introduce read_cpu_topology_map() method 2015-09-14 12:50:28 -03:00
perf.h perf record: Add ability to name registers to record 2015-08-31 18:01:33 -03:00