Gecko [ dataharbor.africa ]

Name	Size	Permission
?;tapset	[ DIR ]	drwxr-xr-x
alias_suffixes.meta	724 B	-rw-r--r--
alias_suffixes.stp	1.04 KB	-rwxr-xr-x
also_ran.meta	605 B	-rw-r--r--
also_ran.stp	769 B	-rwxr-xr-x
ansi_colors.meta	406 B	-rw-r--r--
ansi_colors.stp	716 B	-rwxr-xr-x
ansi_colors2.meta	467 B	-rw-r--r--
ansi_colors2.stp	738 B	-rwxr-xr-x
badname.meta	459 B	-rw-r--r--
badname.stp	1.3 KB	-rwxr-xr-x
badname.txt	126 B	-rw-r--r--
callgraph.meta	388 B	-rw-r--r--
callgraph.stp	212 B	-rwxr-xr-x
callgraph.txt	3.61 KB	-rw-r--r--
click.wav	1.26 KB	-rw-r--r--
cpu_throttle.meta	795 B	-rw-r--r--
cpu_throttle.stp	1.45 KB	-rwxr-xr-x
eventcount.meta	637 B	-rw-r--r--
eventcount.stp	6.77 KB	-rwxr-xr-x
eventcount.txt	1.85 KB	-rw-r--r--
func_time_stats.meta	696 B	-rw-r--r--
func_time_stats.stp	520 B	-rwxr-xr-x
func_time_stats.txt	493 B	-rw-r--r--
grapher.stp	1.26 KB	-rwxr-xr-x
graphs.meta	453 B	-rw-r--r--
graphs.stp	1.46 KB	-rwxr-xr-x
helloworld.meta	298 B	-rw-r--r--
helloworld.stp	57 B	-rwxr-xr-x
key.meta	319 B	-rw-r--r--
key.stp	414 B	-rwxr-xr-x
keyhack.meta	355 B	-rw-r--r--
keyhack.stp	288 B	-rwxr-xr-x
measureinterval.meta	1.54 KB	-rw-r--r--
measureinterval.stp	830 B	-rwxr-xr-x
para-callgraph-verbose.meta	879 B	-rw-r--r--
para-callgraph-verbose.stp	407 B	-rwxr-xr-x
para-callgraph.meta	756 B	-rw-r--r--
para-callgraph.stp	405 B	-rwxr-xr-x
para-callgraph.txt	4.31 KB	-rw-r--r--
py2example.meta	489 B	-rw-r--r--
py2example.stp	761 B	-rw-r--r--
py2example.tcl	79 B	-rw-r--r--
py3example.meta	515 B	-rw-r--r--
py3example.stp	761 B	-rw-r--r--
py3example.tcl	79 B	-rw-r--r--
pyexample.py	832 B	-rw-r--r--
pyexample.pyc	1.06 KB	-rw-r--r--
pyexample.pyo	1.06 KB	-rw-r--r--
regex.meta	504 B	-rw-r--r--
regex.stp	491 B	-rwxr-xr-x
return.wav	6.43 KB	-rw-r--r--
sizeof.meta	499 B	-rw-r--r--
sizeof.stp	496 B	-rwxr-xr-x
sizeof.txt	100 B	-rw-r--r--
sizeof_interactive.meta	816 B	-rw-r--r--
sizeof_interactive.stp	572 B	-rw-r--r--
sizeof_interactive.txt	154 B	-rw-r--r--
socket-events.meta	563 B	-rw-r--r--
socket-events.stp	5.28 KB	-rwxr-xr-x
stopwatches.meta	754 B	-rw-r--r--
stopwatches.stp	957 B	-rwxr-xr-x
tcl-funtop.meta	479 B	-rw-r--r--
tcl-funtop.stp	817 B	-rwxr-xr-x
tcl-trace.meta	364 B	-rw-r--r--
tcl-trace.stp	1.01 KB	-rwxr-xr-x
varwatch.meta	583 B	-rw-r--r--
varwatch.stp	635 B	-rwxr-xr-x
varwatch.txt	2.62 KB	-rw-r--r--
watchdog.meta	922 B	-rw-r--r--
watchdog.stp	447 B	-rwxr-xr-x
whythefail.meta	481 B	-rw-r--r--
whythefail.stp	2.22 KB	-rw-r--r--
whythefail.txt	3.7 KB	-rw-r--r--

Code Editor : whythefail.txt

Some sample uses of whythefail.stp:

------------------------------------------------------------------------

Trace failing cases of do_sys_open, the main outer function behind the
the open(2) syscall.

# stap whythefail.stp kernel do_sys_open '$return < 0' -c 'cat /root/no-such-file || true'
cat: /root/no-such-file: No such file or directory

cat[23342] kernel function(do_sys_open) $return: -2
cat[23342] fs/open.c:992 $$vars: dfd=0xffffffffffffff9c filename=0x7ffc0f9546b9 flags=0x8000 mode=? op={...} fd=? tmp=?
cat[23342] fs/open.c:993 $$vars: dfd=0xffffffffffffff9c filename=? flags=0x8000 mode=? op={...} fd=? tmp=0xffff88002b21d000
cat[23342] fs/open.c:996 $$vars: dfd=0xffffffffffffff9c filename=? flags=0x8000 mode=? op={...} fd=? tmp=0xffff88002b21d000
cat[23342] fs/open.c:997 $$vars: dfd=0xffffffffffffff9c filename=? flags=0x8000 mode=? op={...} fd=? tmp=0xffff88002b21d000
cat[23342] fs/open.c:998 $$vars: f=? dfd=0xffffffffffffff9c filename=? flags=? mode=? op={...} fd=0x3 tmp=0xffff88002b21d000
cat[23342] fs/open.c:999 $$vars: f=? dfd=0xffffffffffffff9c filename=? flags=? mode=? op={...} fd=0x3 tmp=0xffff88002b21d000
cat[23342] fs/open.c:1000 $$vars: f=0xfffffffffffffffe dfd=? filename=? flags=? mode=? op={...} fd=0x3 tmp=0xffff88002b21d000
cat[23342] fs/open.c:1001 $$vars: f=0xfffffffffffffffe dfd=? filename=? flags=? mode=? op={...} fd=0x3 tmp=0xffff88002b21d000
cat[23342] fs/open.c:1007 $$vars: dfd=? filename=? flags=? mode=? op={...} fd=0xfffffffffffffffe tmp=0xffff88002b21d000
cat[23342] fs/open.c:1008 $$vars: dfd=? filename=? flags=? mode=? op={...} fd=0xfffffffffffffffe tmp=0xffff88002b21d000
cat[23342] fs/open.c:1009 $$vars: dfd=? filename=? flags=? mode=? op={...} fd=? tmp=?
[... 6 other traces ...]

statistics:
entry count: 19
exit-hit count: 7
exit-miss count: 12
statement count: 216

------------------------------------------------------------------------

Take a random sampling of do_select runs.  Print a dummy non-existent
variable at the end, because the default '$$vars' is too long.  Also,
disable overload-prevention since select(2) is very heavily used;
might even need a larger -DMAXMAPENTRIES=num and smaller -DMAXSTRINGLEN=num
set.  Note that the line numbers shown allow a pretty good
after-the-fact trace of what happened.

# stap -g --suppress-time-limits whythefail.stp kernel do_select 'randint(1000)<1' '$foo'
[...]
Xorg.bin[2360] kernel function(do_select) $return: 1
Xorg.bin[2360] fs/select.c:410 $foo: ?
Xorg.bin[2360] fs/select.c:413 $foo: ?
Xorg.bin[2360] fs/select.c:419 $foo: ?
Xorg.bin[2360] fs/select.c:425 $foo: ?
Xorg.bin[2360] fs/select.c:424 $foo: ?
Xorg.bin[2360] fs/select.c:407 $foo: ?
Xorg.bin[2360] fs/select.c:401 $foo: ?
Xorg.bin[2360] fs/select.c:432 $foo: ?
Xorg.bin[2360] fs/select.c:435 $foo: ?
Xorg.bin[2360] fs/select.c:433 $foo: ?
Xorg.bin[2360] fs/select.c:439 $foo: ?
Xorg.bin[2360] fs/select.c:440 $foo: ?
Xorg.bin[2360] fs/select.c:441 $foo: ?
Xorg.bin[2360] fs/select.c:448 $foo: ?
Xorg.bin[2360] fs/select.c:450 $foo: ?
Xorg.bin[2360] fs/select.c:446 $foo: ?
Xorg.bin[2360] fs/select.c:450 $foo: ?
Xorg.bin[2360] fs/select.c:453 $foo: ?
Xorg.bin[2360] fs/select.c:457 $foo: ?
Xorg.bin[2360] fs/select.c:460 $foo: ?
Xorg.bin[2360] fs/select.c:463 $foo: ?
Xorg.bin[2360] fs/select.c:468 $foo: ?
Xorg.bin[2360] fs/select.c:473 $foo: ?
[...]
Xorg.bin[2360] fs/select.c:493 $foo: ?
Xorg.bin[2360] fs/select.c:494 $foo: ?
Xorg.bin[2360] fs/select.c:496 $foo: ?
Xorg.bin[2360] fs/select.c:498 $foo: ?
Xorg.bin[2360] fs/select.c:501 $foo: ?
Xorg.bin[2360] fs/select.c:500 $foo: ?
Xorg.bin[2360] fs/select.c:534 $foo: ?
Xorg.bin[2360] fs/select.c:536 $foo: ?
Xorg.bin[2360] fs/select.c:537 $foo: ?
^C
statistics:
entry count: 9261
exit-hit count: 8
exit-miss count: 9231
statement count: 3427078

${this.title}

Code Editor : whythefail.txt