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bpftrace.cpp
1732 lines (1525 loc) · 45.5 KB
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bpftrace.cpp
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#include <assert.h>
#include <fstream>
#include <iomanip>
#include <iostream>
#include <regex>
#include <sstream>
#include <sys/epoll.h>
#include <time.h>
#include <arpa/inet.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/prctl.h>
#include <sys/wait.h>
#include <fcntl.h>
#include <unistd.h>
#include "bcc_syms.h"
#include "perf_reader.h"
#include "bpforc.h"
#include "bpftrace.h"
#include "attached_probe.h"
#include "printf.h"
#include "triggers.h"
#include "resolve_cgroupid.h"
extern char** environ;
namespace bpftrace {
DebugLevel bt_debug = DebugLevel::kNone;
bool bt_verbose = false;
BPFtrace::~BPFtrace()
{
for (int pid : child_pids_)
{
// We don't care if waitpid returns any errors. We're just trying
// to make a best effort here. It's not like we could recover from
// an error.
int status;
waitpid(pid, &status, 0);
}
for (const auto& pair : pid_sym_)
{
if (pair.second)
bcc_free_symcache(pair.second, pair.first);
}
if (ksyms_)
bcc_free_symcache(ksyms_, -1);
}
int BPFtrace::add_probe(ast::Probe &p)
{
for (auto attach_point : *p.attach_points)
{
if (attach_point->provider == "BEGIN")
{
Probe probe;
probe.path = "/proc/self/exe";
probe.attach_point = "BEGIN_trigger";
probe.type = probetype(attach_point->provider);
probe.orig_name = p.name();
probe.name = p.name();
probe.loc = 0;
probe.index = attach_point->index(probe.name) > 0 ?
attach_point->index(probe.name) : p.index();
special_probes_.push_back(probe);
continue;
}
else if (attach_point->provider == "END")
{
Probe probe;
probe.path = "/proc/self/exe";
probe.attach_point = "END_trigger";
probe.type = probetype(attach_point->provider);
probe.orig_name = p.name();
probe.name = p.name();
probe.loc = 0;
probe.index = attach_point->index(probe.name) > 0 ?
attach_point->index(probe.name) : p.index();
special_probes_.push_back(probe);
continue;
}
std::vector<std::string> attach_funcs;
if (attach_point->need_expansion && has_wildcard(attach_point->func))
{
std::set<std::string> matches;
switch (probetype(attach_point->provider))
{
case ProbeType::kprobe:
case ProbeType::kretprobe:
matches = find_wildcard_matches(attach_point->target,
attach_point->func,
"/sys/kernel/debug/tracing/available_filter_functions");
break;
case ProbeType::uprobe:
case ProbeType::uretprobe:
{
auto symbol_stream = std::istringstream(extract_func_symbols_from_path(attach_point->target));
matches = find_wildcard_matches("", attach_point->func, symbol_stream);
break;
}
case ProbeType::tracepoint:
matches = find_wildcard_matches(attach_point->target,
attach_point->func,
"/sys/kernel/debug/tracing/available_events");
break;
default:
std::cerr << "Wildcard matches aren't available on probe type '"
<< attach_point->provider << "'" << std::endl;
return 1;
}
attach_funcs.insert(attach_funcs.end(), matches.begin(), matches.end());
}
else
{
attach_funcs.push_back(attach_point->func);
}
for (auto func : attach_funcs)
{
Probe probe;
probe.path = attach_point->target;
probe.attach_point = func;
probe.type = probetype(attach_point->provider);
probe.orig_name = p.name();
probe.name = attach_point->name(func);
probe.freq = attach_point->freq;
probe.loc = 0;
probe.index = attach_point->index(func) > 0 ?
attach_point->index(func) : p.index();
probes_.push_back(probe);
}
}
return 0;
}
std::set<std::string> BPFtrace::find_wildcard_matches(const std::string &prefix, const std::string &func, std::istream &symbol_name_stream)
{
// Turn glob into a regex
auto regex_str = "(" + std::regex_replace(func, std::regex("\\*"), "[^\\s]*") + ")";
if (prefix != "")
regex_str = prefix + ":" + regex_str;
regex_str = "^" + regex_str;
std::regex func_regex(regex_str);
std::smatch match;
std::string line;
std::set<std::string> matches;
while (std::getline(symbol_name_stream, line))
{
if (std::regex_search(line, match, func_regex))
{
assert(match.size() == 2);
// skip the ".part.N" kprobe variants, as they can't be traced:
if (std::strstr(match.str(1).c_str(), ".part.") == NULL)
matches.insert(match[1]);
}
}
return matches;
}
std::set<std::string> BPFtrace::find_wildcard_matches(const std::string &prefix, const std::string &func, const std::string &file_name)
{
std::ifstream file(file_name);
if (file.fail())
{
throw std::runtime_error("Could not read symbols from \"" + file_name + "\", err=" + std::to_string(errno));
}
std::stringstream symbol_name_stream;
std::string line;
while (file >> line)
{
symbol_name_stream << line << std::endl;
}
file.close();
return find_wildcard_matches(prefix, func, symbol_name_stream);
}
int BPFtrace::num_probes() const
{
return special_probes_.size() + probes_.size();
}
void perf_event_printer(void *cb_cookie, void *data, int size __attribute__((unused)))
{
auto bpftrace = static_cast<BPFtrace*>(cb_cookie);
auto printf_id = *static_cast<uint64_t*>(data);
auto arg_data = static_cast<uint8_t*>(data);
int err;
// async actions
if (printf_id == asyncactionint(AsyncAction::exit))
{
err = bpftrace->print_maps();
exit(err);
}
else if (printf_id == asyncactionint(AsyncAction::print))
{
std::string arg = (const char *)(static_cast<uint8_t*>(data) + sizeof(uint64_t) + 2 * sizeof(uint64_t));
uint64_t top = (uint64_t)*(static_cast<uint64_t*>(data) + sizeof(uint64_t) / sizeof(uint64_t));
uint64_t div = (uint64_t)*(static_cast<uint64_t*>(data) + (sizeof(uint64_t) + sizeof(uint64_t)) / sizeof(uint64_t));
err = bpftrace->print_map_ident(arg, top, div);
if (err)
throw std::runtime_error("Could not print map with ident \"" + arg + "\", err=" + std::to_string(err));
return;
}
else if (printf_id == asyncactionint(AsyncAction::clear))
{
std::string arg = (const char *)(arg_data+sizeof(uint64_t));
err = bpftrace->clear_map_ident(arg);
if (err)
throw std::runtime_error("Could not clear map with ident \"" + arg + "\", err=" + std::to_string(err));
return;
}
else if (printf_id == asyncactionint(AsyncAction::zero))
{
std::string arg = (const char *)(arg_data+sizeof(uint64_t));
err = bpftrace->zero_map_ident(arg);
if (err)
throw std::runtime_error("Could not zero map with ident \"" + arg + "\", err=" + std::to_string(err));
return;
}
else if (printf_id == asyncactionint(AsyncAction::time))
{
char timestr[STRING_SIZE];
time_t t;
struct tm *tmp;
t = time(NULL);
tmp = localtime(&t);
if (tmp == NULL) {
perror("localtime");
return;
}
uint64_t time_id = (uint64_t)*(static_cast<uint64_t*>(data) + sizeof(uint64_t) / sizeof(uint64_t));
auto fmt = bpftrace->time_args_[time_id].c_str();
if (strftime(timestr, sizeof(timestr), fmt, tmp) == 0) {
fprintf(stderr, "strftime returned 0");
return;
}
printf("%s", timestr);
return;
}
else if (printf_id == asyncactionint(AsyncAction::join))
{
const char *joinstr = " ";
for (int i = 0; i < bpftrace->join_argnum_; i++) {
auto *arg = arg_data+sizeof(uint64_t) + i * bpftrace->join_argsize_;
if (arg[0] == 0)
break;
if (i)
printf("%s", joinstr);
printf("%s", arg);
}
printf("\n");
return;
}
else if ( printf_id >= asyncactionint(AsyncAction::syscall))
{
auto id = printf_id - asyncactionint(AsyncAction::syscall);
auto fmt = std::get<0>(bpftrace->system_args_[id]).c_str();
auto args = std::get<1>(bpftrace->system_args_[id]);
auto arg_values = bpftrace->get_arg_values(args, arg_data);
char buffer [255];
switch (args.size())
{
case 0:
system(fmt);
break;
case 1:
snprintf(buffer, 255, fmt, arg_values.at(0)->value());
system(buffer);
break;
case 2:
snprintf(buffer, 255, fmt, arg_values.at(0)->value(), arg_values.at(1)->value());
system(buffer);
break;
case 3:
snprintf(buffer, 255, fmt, arg_values.at(0)->value(), arg_values.at(1)->value(), arg_values.at(2)->value());
system(buffer);
break;
case 4:
snprintf(buffer, 255, fmt, arg_values.at(0)->value(), arg_values.at(1)->value(), arg_values.at(2)->value(),
arg_values.at(3)->value());
system(buffer);
break;
case 5:
snprintf(buffer, 255, fmt, arg_values.at(0)->value(), arg_values.at(1)->value(), arg_values.at(2)->value(),
arg_values.at(3)->value(), arg_values.at(4)->value());
system(buffer);
break;
case 6:
snprintf(buffer, 255, fmt, arg_values.at(0)->value(), arg_values.at(1)->value(), arg_values.at(2)->value(),
arg_values.at(3)->value(), arg_values.at(4)->value(), arg_values.at(5)->value());
system(buffer);
break;
default:
std::cerr << "printf() can only take up to 7 arguments (" << args.size() << ") provided" << std::endl;
abort();
}
return;
}
// printf
auto fmt = std::get<0>(bpftrace->printf_args_[printf_id]).c_str();
auto args = std::get<1>(bpftrace->printf_args_[printf_id]);
auto arg_values = bpftrace->get_arg_values(args, arg_data);
switch (args.size())
{
case 0:
printf(fmt);
break;
case 1:
printf(fmt, arg_values.at(0)->value());
break;
case 2:
printf(fmt, arg_values.at(0)->value(), arg_values.at(1)->value());
break;
case 3:
printf(fmt, arg_values.at(0)->value(), arg_values.at(1)->value(), arg_values.at(2)->value());
break;
case 4:
printf(fmt, arg_values.at(0)->value(), arg_values.at(1)->value(), arg_values.at(2)->value(),
arg_values.at(3)->value());
break;
case 5:
printf(fmt, arg_values.at(0)->value(), arg_values.at(1)->value(), arg_values.at(2)->value(),
arg_values.at(3)->value(), arg_values.at(4)->value());
break;
case 6:
printf(fmt, arg_values.at(0)->value(), arg_values.at(1)->value(), arg_values.at(2)->value(),
arg_values.at(3)->value(), arg_values.at(4)->value(), arg_values.at(5)->value());
break;
default:
std::cerr << "printf() can only take up to 7 arguments (" << args.size() << ") provided" << std::endl;
abort();
}
}
std::vector<std::unique_ptr<IPrintable>> BPFtrace::get_arg_values(const std::vector<Field> &args, uint8_t* arg_data)
{
std::vector<std::unique_ptr<IPrintable>> arg_values;
for (auto arg : args)
{
switch (arg.type.type)
{
case Type::integer:
switch (arg.type.size)
{
case 8:
arg_values.push_back(
std::make_unique<PrintableInt>(
*reinterpret_cast<uint64_t*>(arg_data+arg.offset)));
break;
case 4:
arg_values.push_back(
std::make_unique<PrintableInt>(
*reinterpret_cast<uint32_t*>(arg_data+arg.offset)));
break;
case 2:
arg_values.push_back(
std::make_unique<PrintableInt>(
*reinterpret_cast<uint16_t*>(arg_data+arg.offset)));
break;
case 1:
arg_values.push_back(
std::make_unique<PrintableInt>(
*reinterpret_cast<uint8_t*>(arg_data+arg.offset)));
break;
default:
std::cerr << "get_arg_values: invalid integer size. 8, 4, 2 and byte supported. " << arg.type.size << "provided" << std::endl;
abort();
}
break;
case Type::string:
arg_values.push_back(
std::make_unique<PrintableCString>(
reinterpret_cast<char *>(arg_data+arg.offset)));
break;
case Type::ksym:
arg_values.push_back(
std::make_unique<PrintableString>(
resolve_ksym(*reinterpret_cast<uint64_t*>(arg_data+arg.offset))));
break;
case Type::usym:
arg_values.push_back(
std::make_unique<PrintableString>(
resolve_usym(
*reinterpret_cast<uint64_t*>(arg_data+arg.offset),
*reinterpret_cast<uint64_t*>(arg_data+arg.offset + 8))));
break;
case Type::inet:
arg_values.push_back(
std::make_unique<PrintableString>(
resolve_inet(
*reinterpret_cast<uint64_t*>(arg_data+arg.offset),
*reinterpret_cast<uint64_t*>(arg_data+arg.offset+8))));
break;
case Type::username:
arg_values.push_back(
std::make_unique<PrintableString>(
resolve_uid(
*reinterpret_cast<uint64_t*>(arg_data+arg.offset))));
break;
case Type::probe:
arg_values.push_back(
std::make_unique<PrintableString>(
resolve_probe(
*reinterpret_cast<uint64_t*>(arg_data+arg.offset))));
break;
case Type::kstack:
arg_values.push_back(
std::make_unique<PrintableString>(
get_stack(
*reinterpret_cast<uint64_t*>(arg_data+arg.offset),
false,
8)));
break;
case Type::ustack:
arg_values.push_back(
std::make_unique<PrintableString>(
get_stack(
*reinterpret_cast<uint64_t*>(arg_data+arg.offset),
true,
8)));
break;
default:
std::cerr << "invalid argument type" << std::endl;
abort();
}
}
return arg_values;
}
bool BPFtrace::is_numeric(std::string str)
{
int i = 0;
while (str[i]) {
if (str[i] < '0' || str[i] > '9')
return false;
i++;
}
if (i == 0)
return false;
return true;
}
void BPFtrace::add_param(const std::string ¶m)
{
params_.emplace_back(param);
}
std::string BPFtrace::get_param(size_t i)
{
if (i > 0 && i < params_.size() + 1)
return params_[i - 1];
return "0";
}
void perf_event_lost(void *cb_cookie __attribute__((unused)), uint64_t lost)
{
printf("Lost %lu events\n", lost);
}
std::unique_ptr<AttachedProbe> BPFtrace::attach_probe(Probe &probe, const BpfOrc &bpforc)
{
// use the single-probe program if it exists (as is the case with wildcards
// and the name builtin, which must be expanded into separate programs per
// probe), else try to find a the program based on the original probe name
// that includes wildcards.
std::string index_str = "_" + std::to_string(probe.index);
auto func = bpforc.sections_.find("s_" + probe.name + index_str);
if (func == bpforc.sections_.end())
func = bpforc.sections_.find("s_" + probe.orig_name + index_str);
if (func == bpforc.sections_.end())
{
if (probe.name != probe.orig_name)
std::cerr << "Code not generated for probe: " << probe.name << " from: " << probe.orig_name << std::endl;
else
std::cerr << "Code not generated for probe: " << probe.name << std::endl;
return nullptr;
}
try
{
if (probe.type == ProbeType::usdt)
return std::make_unique<AttachedProbe>(probe, func->second, pid_);
else
return std::make_unique<AttachedProbe>(probe, func->second);
}
catch (std::runtime_error &e)
{
std::cerr << e.what() << std::endl;
}
return nullptr;
}
int BPFtrace::run(std::unique_ptr<BpfOrc> bpforc)
{
auto r_special_probes = special_probes_.rbegin();
for (; r_special_probes != special_probes_.rend(); ++r_special_probes)
{
auto attached_probe = attach_probe(*r_special_probes, *bpforc.get());
if (attached_probe == nullptr)
return -1;
special_attached_probes_.push_back(std::move(attached_probe));
}
int epollfd = setup_perf_events();
if (epollfd < 0)
return epollfd;
// Spawn a child process if we've been passed a command to run
if (cmd_.size())
{
auto args = split_string(cmd_, ' ');
args[0] = resolve_binary_path(args[0]); // does path lookup on executable
int pid = spawn_child(args);
if (pid < 0)
{
std::cerr << "Failed to spawn child=" << cmd_ << std::endl;
return pid;
}
child_pids_.emplace_back(pid);
pid_ = pid;
}
BEGIN_trigger();
// NOTE (mmarchini): Apparently the kernel fires kprobe_events in the reverse
// order they were attached, so we insert them backwards to make sure blocks
// are executed in the same order they were declared.
auto r_probes = probes_.rbegin();
for (; r_probes != probes_.rend(); ++r_probes)
{
auto attached_probe = attach_probe(*r_probes, *bpforc.get());
if (attached_probe == nullptr)
return -1;
attached_probes_.push_back(std::move(attached_probe));
}
if (bt_verbose)
std::cerr << "Running..." << std::endl;
poll_perf_events(epollfd);
attached_probes_.clear();
END_trigger();
poll_perf_events(epollfd, true);
special_attached_probes_.clear();
return 0;
}
int BPFtrace::setup_perf_events()
{
int epollfd = epoll_create1(EPOLL_CLOEXEC);
if (epollfd == -1)
{
std::cerr << "Failed to create epollfd" << std::endl;
return -1;
}
std::vector<int> cpus = get_online_cpus();
online_cpus_ = cpus.size();
for (int cpu : cpus)
{
int page_cnt = 64;
void *reader = bpf_open_perf_buffer(&perf_event_printer, &perf_event_lost, this, -1, cpu, page_cnt);
if (reader == nullptr)
{
std::cerr << "Failed to open perf buffer" << std::endl;
return -1;
}
struct epoll_event ev = {};
ev.events = EPOLLIN;
ev.data.ptr = reader;
int reader_fd = perf_reader_fd((perf_reader*)reader);
bpf_update_elem(perf_event_map_->mapfd_, &cpu, &reader_fd, 0);
if (epoll_ctl(epollfd, EPOLL_CTL_ADD, reader_fd, &ev) == -1)
{
std::cerr << "Failed to add perf reader to epoll" << std::endl;
return -1;
}
}
return epollfd;
}
void BPFtrace::poll_perf_events(int epollfd, bool drain)
{
auto events = std::vector<struct epoll_event>(online_cpus_);
while (true)
{
int ready = epoll_wait(epollfd, events.data(), online_cpus_, 100);
// Return if either
// * epoll_wait has encountered an error (eg signal delivery)
// * There's no events left and we've been instructed to drain
if (ready < 0 || (ready == 0 && drain))
{
return;
}
for (int i=0; i<ready; i++)
{
perf_reader_event_read((perf_reader*)events[i].data.ptr);
}
// If we are tracing a specific pid and it has exited, we should exit
// as well b/c otherwise we'd be tracing nothing.
//
// Note that there technically is a race with a new process using the
// same pid, but we're polling at 100ms and it would be unlikely that
// the pids wrap around that fast.
if (pid_ > 0 && !is_pid_alive(pid_))
{
return;
}
}
return;
}
int BPFtrace::print_maps()
{
for(auto &mapmap : maps_)
{
IMap &map = *mapmap.second.get();
int err;
if (map.type_.type == Type::hist || map.type_.type == Type::lhist)
err = print_map_hist(map, 0, 0);
else if (map.type_.type == Type::avg || map.type_.type == Type::stats)
err = print_map_stats(map);
else
err = print_map(map, 0, 0);
std::cout << std::endl;
if (err)
return err;
}
return 0;
}
// print a map given an ident string
int BPFtrace::print_map_ident(const std::string &ident, uint32_t top, uint32_t div)
{
int err = 0;
for(auto &mapmap : maps_)
{
IMap &map = *mapmap.second.get();
if (map.name_ == ident) {
if (map.type_.type == Type::hist || map.type_.type == Type::lhist)
err = print_map_hist(map, top, div);
else if (map.type_.type == Type::avg || map.type_.type == Type::stats)
err = print_map_stats(map);
else
err = print_map(map, top, div);
return err;
}
}
return -2;
}
// clear a map (delete all keys) given an ident string
int BPFtrace::clear_map_ident(const std::string &ident)
{
int err = 0;
for(auto &mapmap : maps_)
{
IMap &map = *mapmap.second.get();
if (map.name_ == ident) {
err = clear_map(map);
return err;
}
}
return -2;
}
// zero a map (set all keys to zero) given an ident string
int BPFtrace::zero_map_ident(const std::string &ident)
{
int err = 0;
for(auto &mapmap : maps_)
{
IMap &map = *mapmap.second.get();
if (map.name_ == ident) {
err = zero_map(map);
return err;
}
}
return -2;
}
// clear a map
int BPFtrace::clear_map(IMap &map)
{
std::vector<uint8_t> old_key;
try
{
if (map.type_.type == Type::hist)
// hist maps have 8 extra bytes for the bucket number
old_key = find_empty_key(map, map.key_.size() + 8);
else
old_key = find_empty_key(map, map.key_.size());
}
catch (std::runtime_error &e)
{
std::cerr << "Error getting key for map '" << map.name_ << "': "
<< e.what() << std::endl;
return -2;
}
auto key(old_key);
// snapshot keys, then operate on them
std::vector<std::vector<uint8_t>> keys;
while (bpf_get_next_key(map.mapfd_, old_key.data(), key.data()) == 0)
{
keys.push_back(key);
old_key = key;
}
for (auto &key : keys)
{
int err = bpf_delete_elem(map.mapfd_, key.data());
if (err)
{
std::cerr << "Error looking up elem: " << err << std::endl;
return -1;
}
}
return 0;
}
// zero a map
int BPFtrace::zero_map(IMap &map)
{
std::vector<uint8_t> old_key;
try
{
if (map.type_.type == Type::hist || map.type_.type == Type::lhist ||
map.type_.type == Type::stats || map.type_.type == Type::avg)
// hist maps have 8 extra bytes for the bucket number
old_key = find_empty_key(map, map.key_.size() + 8);
else
old_key = find_empty_key(map, map.key_.size());
}
catch (std::runtime_error &e)
{
std::cerr << "Error getting key for map '" << map.name_ << "': "
<< e.what() << std::endl;
return -2;
}
auto key(old_key);
// snapshot keys, then operate on them
std::vector<std::vector<uint8_t>> keys;
while (bpf_get_next_key(map.mapfd_, old_key.data(), key.data()) == 0)
{
keys.push_back(key);
old_key = key;
}
int value_size = map.type_.size;
if (map.type_.type == Type::count || map.type_.type == Type::sum ||
map.type_.type == Type::min || map.type_.type == Type::max ||
map.type_.type == Type::avg || map.type_.type == Type::hist ||
map.type_.type == Type::lhist || map.type_.type == Type::stats )
value_size *= ncpus_;
std::vector<uint8_t> zero(value_size, 0);
for (auto &key : keys)
{
int err = bpf_update_elem(map.mapfd_, key.data(), zero.data(), BPF_EXIST);
if (err)
{
std::cerr << "Error looking up elem: " << err << std::endl;
return -1;
}
}
return 0;
}
int BPFtrace::print_map(IMap &map, uint32_t top, uint32_t div)
{
std::vector<uint8_t> old_key;
try
{
old_key = find_empty_key(map, map.key_.size());
}
catch (std::runtime_error &e)
{
std::cerr << "Error getting key for map '" << map.name_ << "': "
<< e.what() << std::endl;
return -2;
}
auto key(old_key);
std::vector<std::pair<std::vector<uint8_t>, std::vector<uint8_t>>> values_by_key;
while (bpf_get_next_key(map.mapfd_, old_key.data(), key.data()) == 0)
{
int value_size = map.type_.size;
if (map.type_.type == Type::count || map.type_.type == Type::sum ||
map.type_.type == Type::min || map.type_.type == Type::max)
value_size *= ncpus_;
auto value = std::vector<uint8_t>(value_size);
int err = bpf_lookup_elem(map.mapfd_, key.data(), value.data());
if (err)
{
std::cerr << "Error looking up elem: " << err << std::endl;
return -1;
}
values_by_key.push_back({key, value});
old_key = key;
}
if (map.type_.type == Type::count || map.type_.type == Type::sum)
{
std::sort(values_by_key.begin(), values_by_key.end(), [&](auto &a, auto &b)
{
return reduce_value(a.second, ncpus_) < reduce_value(b.second, ncpus_);
});
}
else if (map.type_.type == Type::min)
{
std::sort(values_by_key.begin(), values_by_key.end(), [&](auto &a, auto &b)
{
return min_value(a.second, ncpus_) < min_value(b.second, ncpus_);
});
}
else if (map.type_.type == Type::max)
{
std::sort(values_by_key.begin(), values_by_key.end(), [&](auto &a, auto &b)
{
return max_value(a.second, ncpus_) < max_value(b.second, ncpus_);
});
}
else
{
sort_by_key(map.key_.args_, values_by_key);
};
if (div == 0)
div = 1;
uint32_t i = 0;
size_t total = values_by_key.size();
for (auto &pair : values_by_key)
{
auto key = pair.first;
auto value = pair.second;
if (top)
{
if (total > top && i++ < (total - top))
continue;
}
std::cout << map.name_ << map.key_.argument_value_list(*this, key) << ": ";
if (map.type_.type == Type::kstack)
std::cout << get_stack(*(uint64_t*)value.data(), false, 8);
else if (map.type_.type == Type::ustack)
std::cout << get_stack(*(uint64_t*)value.data(), true, 8);
else if (map.type_.type == Type::ksym)
std::cout << resolve_ksym(*(uintptr_t*)value.data());
else if (map.type_.type == Type::usym)
std::cout << resolve_usym(*(uintptr_t*)value.data(), *(uint64_t*)(value.data() + 8));
else if (map.type_.type == Type::inet)
std::cout << resolve_inet(*(uintptr_t*)value.data(), *(uint64_t*)(value.data() + 8));
else if (map.type_.type == Type::username)
std::cout << resolve_uid(*(uint64_t*)(value.data())) << std::endl;
else if (map.type_.type == Type::string)
std::cout << value.data() << std::endl;
else if (map.type_.type == Type::count || map.type_.type == Type::sum)
std::cout << reduce_value(value, ncpus_) / div << std::endl;
else if (map.type_.type == Type::min)
std::cout << min_value(value, ncpus_) / div << std::endl;
else if (map.type_.type == Type::max)
std::cout << max_value(value, ncpus_) / div << std::endl;
else if (map.type_.type == Type::probe)
std::cout << resolve_probe(*(uint64_t*)value.data()) << std::endl;
else
std::cout << *(int64_t*)value.data() / div << std::endl;
}
if (i == 0)
std::cout << std::endl;
return 0;
}
int BPFtrace::print_map_hist(IMap &map, uint32_t top, uint32_t div)
{
// A hist-map adds an extra 8 bytes onto the end of its key for storing
// the bucket number.
// e.g. A map defined as: @x[1, 2] = @hist(3);
// would actually be stored with the key: [1, 2, 3]
std::vector<uint8_t> old_key;
try
{
old_key = find_empty_key(map, map.key_.size() + 8);
}
catch (std::runtime_error &e)
{
std::cerr << "Error getting key for map '" << map.name_ << "': "
<< e.what() << std::endl;
return -2;
}
auto key(old_key);
std::map<std::vector<uint8_t>, std::vector<uint64_t>> values_by_key;
while (bpf_get_next_key(map.mapfd_, old_key.data(), key.data()) == 0)
{
auto key_prefix = std::vector<uint8_t>(map.key_.size());
int bucket = key.at(map.key_.size());
for (size_t i=0; i<map.key_.size(); i++)
key_prefix.at(i) = key.at(i);
int value_size = map.type_.size * ncpus_;
auto value = std::vector<uint8_t>(value_size);
int err = bpf_lookup_elem(map.mapfd_, key.data(), value.data());
if (err)
{
std::cerr << "Error looking up elem: " << err << std::endl;
return -1;
}
if (values_by_key.find(key_prefix) == values_by_key.end())
{
// New key - create a list of buckets for it
if (map.type_.type == Type::hist)
values_by_key[key_prefix] = std::vector<uint64_t>(65);
else
values_by_key[key_prefix] = std::vector<uint64_t>(1002);
}
values_by_key[key_prefix].at(bucket) = reduce_value(value, ncpus_);
old_key = key;
}
// Sort based on sum of counts in all buckets
std::vector<std::pair<std::vector<uint8_t>, uint64_t>> total_counts_by_key;
for (auto &map_elem : values_by_key)
{
int sum = 0;
for (size_t i=0; i<map_elem.second.size(); i++)
{
sum += map_elem.second.at(i);
}
total_counts_by_key.push_back({map_elem.first, sum});
}
std::sort(total_counts_by_key.begin(), total_counts_by_key.end(), [&](auto &a, auto &b)
{
return a.second < b.second;
});
if (div == 0)
div = 1;
uint32_t i = 0;
for (auto &key_count : total_counts_by_key)
{
auto &key = key_count.first;
auto &value = values_by_key[key];
if (top)
{
if (i++ < (values_by_key.size() - top))
continue;
}
std::cout << map.name_ << map.key_.argument_value_list(*this, key) << ": " << std::endl;
if (map.type_.type == Type::hist)