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Commit c9551307 authored by Sasha Goldshtein's avatar Sasha Goldshtein
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Print traceback only if verbose mode was requested

parent a6f5a219
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Showing with 108 additions and 78 deletions
tools/argdist.py
View file @ c9551307
......@@ -16,6 +16,8 @@ from bcc import BPF
from time import sleep, strftime
import argparse
import re
import traceback
import sys
class Specifier(object):
probe_text = """
......@@ -45,7 +47,7 @@ int PROBENAME(struct pt_regs *ctx SIGNATURE)
headers = ""
for header, keywords in Specifier.auto_includes.items():
for keyword in keywords:
for specifier in specifiers:
for specifier in specifiers:
if keyword in specifier:
headers += "#include <%s>\n" \
% header
......@@ -207,7 +209,7 @@ u64 __time = bpf_ktime_get_ns();
def __init__(self, type, specifier, pid):
self.raw_spec = specifier
self._validate_specifier()
spec_and_label = specifier.split('#')
self.label = spec_and_label[1] \
if len(spec_and_label) == 2 else None
......@@ -242,7 +244,7 @@ u64 __time = bpf_ktime_get_ns();
self.filter = "" if len(parts) != 6 else parts[5]
self._substitute_exprs()
# Do we need to attach an entry probe so that we can collect an
# Do we need to attach an entry probe so that we can collect an
# argument that is required for an exit (return) probe?
def check(expr):
keywords = ["$entry", "$latency"]
......@@ -303,13 +305,13 @@ u64 __time = bpf_ktime_get_ns();
text = "struct %s_key_t __key = {};\n" % \
self.probe_hash_name
for i in range(0, len(self.exprs)):
text += self._generate_field_assignment(i)
text += self._generate_field_assignment(i)
return text
def _generate_hash_update(self):
if self.type == "hist":
return "%s.increment(bpf_log2l(__key));" % \
self.probe_hash_name
self.probe_hash_name
else:
return "%s.increment(__key);" % self.probe_hash_name
......@@ -335,7 +337,7 @@ u64 __time = bpf_ktime_get_ns();
prefix = ""
if self.entry_probe_required:
program = self._generate_entry_probe()
prefix = self._generate_retprobe_prefix()
prefix = self._generate_retprobe_prefix()
# Replace $entry(paramname) with a reference to the
# value we collected when entering the function:
self._replace_entry_exprs()
......@@ -353,9 +355,9 @@ u64 __time = bpf_ktime_get_ns();
key_expr = self._generate_key_assignment()
collect = self._generate_hash_update()
program = program.replace("DATA_DECL", decl)
program = program.replace("KEY_EXPR", key_expr)
program = program.replace("KEY_EXPR", key_expr)
program = program.replace("FILTER",
"1" if len(self.filter) == 0 else self.filter)
"1" if len(self.filter) == 0 else self.filter)
program = program.replace("COLLECT", collect)
program = program.replace("PREFIX", prefix)
return program
......@@ -396,7 +398,7 @@ u64 __time = bpf_ktime_get_ns();
"(bpf_ktime_get_ns() - *____latency_val)", "$latency")
# Replace alias values back with the alias name
for alias, subst in Specifier.aliases.items():
expr = expr.replace(subst, alias)
expr = expr.replace(subst, alias)
# Replace retval expression with $retval
expr = expr.replace("ctx->ax", "$retval")
# Replace ugly (*__param_val) expressions with param name
......@@ -425,7 +427,7 @@ u64 __time = bpf_ktime_get_ns();
data = sorted(data.items(), key=lambda kv: kv[1].value)
if top is not None:
data = data[-top:]
for key, value in data:
for key, value in data:
# Print some nice values if the user didn't
# specify an expression to probe
if self.is_default_expr:
......@@ -435,7 +437,7 @@ u64 __time = bpf_ktime_get_ns();
key_str = "retval = %s" % \
self._v2s(key.v0)
else:
key_str = self._display_key(key)
key_str = self._display_key(key)
print("\t%-10s %s" % \
(str(value.value), key_str))
elif self.type == "hist":
......@@ -443,7 +445,8 @@ u64 __time = bpf_ktime_get_ns();
if not self.is_default_expr else "retval")
data.print_log2_hist(val_type=label)
examples = """
class Tool(object):
examples = """
Probe specifier syntax:
{p,r}:[library]:function(signature)[:type[,type...]:expr[,expr...][:filter]][#label]
Where:
......@@ -487,7 +490,7 @@ argdist -p 1005 -H 'r:c:read()'
argdist -C 'r::__vfs_read():u32:$PID:$latency > 100000'
Print frequency of reads by process where the latency was >0.1ms
argdist -H 'r::__vfs_read(void *file, void *buf, size_t count):size_t:$entry(count):$latency > 1000000'
argdist -H 'r::__vfs_read(void *file, void *buf, size_t count):size_t:$entry(count):$latency > 1000000'
Print a histogram of read sizes that were longer than 1ms
argdist -H \\
......@@ -497,7 +500,7 @@ argdist -H \\
argdist -C 'p:c:fork()#fork calls'
Count fork() calls in libc across all processes
Can also use funccount.py, which is easier and more flexible
Can also use funccount.py, which is easier and more flexible
argdist -H \\
'p:c:sleep(u32 seconds):u32:seconds' \\
......@@ -507,72 +510,99 @@ argdist -H \\
argdist -p 2780 -z 120 \\
-C 'p:c:write(int fd, char* buf, size_t len):char*:buf:fd==1'
Spy on writes to STDOUT performed by process 2780, up to a string size
of 120 characters
of 120 characters
"""
parser = argparse.ArgumentParser(description=
"Trace a function and display a summary of its parameter values.",
formatter_class=argparse.RawDescriptionHelpFormatter,
epilog=examples)
parser.add_argument("-p", "--pid", type=int,
help="id of the process to trace (optional)")
parser.add_argument("-z", "--string-size", default=80, type=int,
help="maximum string size to read from char* arguments")
parser.add_argument("-i", "--interval", default=1, type=int,
help="output interval, in seconds")
parser.add_argument("-n", "--number", type=int, dest="count",
help="number of outputs")
parser.add_argument("-v", "--verbose", action="store_true",
help="print resulting BPF program code before executing")
parser.add_argument("-T", "--top", type=int,
help="number of top results to show (not applicable to histograms)")
parser.add_argument("-H", "--histogram", nargs="*", dest="histspecifier",
metavar="specifier",
help="probe specifier to capture histogram of (see examples below)")
parser.add_argument("-C", "--count", nargs="*", dest="countspecifier",
metavar="specifier",
help="probe specifier to capture count of (see examples below)")
parser.add_argument("-I", "--include", nargs="*", metavar="header",
help="additional header files to include in the BPF program")
args = parser.parse_args()
specifiers = []
for specifier in (args.countspecifier or []):
specifiers.append(Specifier("freq", specifier, args.pid))
for histspecifier in (args.histspecifier or []):
specifiers.append(Specifier("hist", histspecifier, args.pid))
if len(specifiers) == 0:
print("at least one specifier is required")
exit(1)
bpf_source = """
def __init__(self):
parser = argparse.ArgumentParser(description="Trace a " +
"function and display a summary of its parameter values.",
formatter_class=argparse.RawDescriptionHelpFormatter,
epilog=Tool.examples)
parser.add_argument("-p", "--pid", type=int,
help="id of the process to trace (optional)")
parser.add_argument("-z", "--string-size", default=80,
type=int,
help="maximum string size to read from char* arguments")
parser.add_argument("-i", "--interval", default=1, type=int,
help="output interval, in seconds")
parser.add_argument("-n", "--number", type=int, dest="count",
help="number of outputs")
parser.add_argument("-v", "--verbose", action="store_true",
help="print resulting BPF program code before executing")
parser.add_argument("-T", "--top", type=int,
help="number of top results to show (not applicable to " +
"histograms)")
parser.add_argument("-H", "--histogram", nargs="*",
dest="histspecifier", metavar="specifier",
help="probe specifier to capture histogram of " +
"(see examples below)")
parser.add_argument("-C", "--count", nargs="*",
dest="countspecifier", metavar="specifier",
help="probe specifier to capture count of " +
"(see examples below)")
parser.add_argument("-I", "--include", nargs="*",
metavar="header",
help="additional header files to include in the BPF program")
self.args = parser.parse_args()
def _create_specifiers(self):
self.specifiers = []
for specifier in (self.args.countspecifier or []):
self.specifiers.append(Specifier(
"freq", specifier, self.args.pid))
for histspecifier in (self.args.histspecifier or []):
self.specifiers.append(
Specifier("hist", histspecifier, self.args.pid))
if len(self.specifiers) == 0:
print("at least one specifier is required")
exit(1)
def _generate_program(self):
bpf_source = """
struct __string_t { char s[%d]; };
#include <uapi/linux/ptrace.h>
""" % args.string_size
for include in (args.include or []):
bpf_source += "#include <%s>\n" % include
bpf_source += Specifier.generate_auto_includes(map(lambda s: s.raw_spec, specifiers))
for specifier in specifiers:
bpf_source += specifier.generate_text()
if args.verbose:
print(bpf_source)
bpf = BPF(text=bpf_source)
for specifier in specifiers:
specifier.attach(bpf)
count_so_far = 0
while True:
try:
sleep(args.interval)
except KeyboardInterrupt:
exit()
print("[%s]" % strftime("%H:%M:%S"))
for specifier in specifiers:
specifier.display(args.top)
count_so_far += 1
if args.count is not None and count_so_far >= args.count:
exit()
""" % self.args.string_size
for include in (self.args.include or []):
bpf_source += "#include <%s>\n" % include
bpf_source += Specifier.generate_auto_includes(
map(lambda s: s.raw_spec, self.specifiers))
for specifier in self.specifiers:
bpf_source += specifier.generate_text()
if self.args.verbose:
print(bpf_source)
self.bpf = BPF(text=bpf_source)
def _attach(self):
for specifier in self.specifiers:
specifier.attach(self.bpf)
def _main_loop(self):
count_so_far = 0
while True:
try:
sleep(self.args.interval)
except KeyboardInterrupt:
exit()
print("[%s]" % strftime("%H:%M:%S"))
for specifier in self.specifiers:
specifier.display(self.args.top)
count_so_far += 1
if self.args.count is not None and \
count_so_far >= self.args.count:
exit()
def run(self):
try:
self._create_specifiers()
self._generate_program()
self._attach()
self._main_loop()
except:
if self.args.verbose:
traceback.print_exc()
else:
print(sys.exc_value)
if __name__ == "__main__":
Tool().run()
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