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/*
* Copyright (C) 2018 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "src/profiling/common/proc_utils.h"
#include <inttypes.h>
#include <sys/stat.h>
#include <unistd.h>
#include "perfetto/ext/base/file_utils.h"
#include "perfetto/ext/base/optional.h"
#include "perfetto/profiling/normalize.h"
namespace perfetto {
namespace profiling {
namespace {
bool GetProcFile(pid_t pid, const char* file, char* filename_buf, size_t size) {
ssize_t written = snprintf(filename_buf, size, "/proc/%d/%s", pid, file);
if (written < 0 || static_cast<size_t>(written) >= size) {
if (written < 0)
PERFETTO_ELOG("Failed to concatenate cmdline file.");
else
PERFETTO_ELOG("Overflow when concatenating cmdline file.");
return false;
}
return true;
}
base::Optional<uint32_t> ParseProcStatusSize(const std::string& status,
const std::string& key) {
auto entry_idx = status.find(key);
if (entry_idx == std::string::npos)
return {};
entry_idx = status.find_first_not_of(" \t", entry_idx + key.size());
if (entry_idx == std::string::npos)
return {};
int32_t val = atoi(status.c_str() + entry_idx);
if (val < 0) {
PERFETTO_ELOG("Unexpected value reading %s", key.c_str());
return {};
}
return static_cast<uint32_t>(val);
}
} // namespace
base::Optional<std::vector<std::string>> NormalizeCmdlines(
const std::vector<std::string>& cmdlines) {
std::vector<std::string> normalized_cmdlines;
normalized_cmdlines.reserve(cmdlines.size());
for (size_t i = 0; i < cmdlines.size(); i++) {
std::string cmdline = cmdlines[i]; // mutable copy
// Add nullbyte to make sure it's a C string.
cmdline.resize(cmdline.size() + 1, '\0');
char* cmdline_cstr = &(cmdline[0]);
ssize_t size = NormalizeCmdLine(&cmdline_cstr, cmdline.size());
if (size == -1) {
PERFETTO_PLOG("Failed to normalize cmdline %s. Stopping the parse.",
cmdlines[i].c_str());
return base::nullopt;
}
normalized_cmdlines.emplace_back(cmdline_cstr, static_cast<size_t>(size));
}
return base::make_optional(normalized_cmdlines);
}
// This is mostly the same as GetHeapprofdProgramProperty in
// https://android.googlesource.com/platform/bionic/+/master/libc/bionic/malloc_common.cpp
// This should give the same result as GetHeapprofdProgramProperty.
bool GetCmdlineForPID(pid_t pid, std::string* name) {
std::string filename = "/proc/" + std::to_string(pid) + "/cmdline";
base::ScopedFile fd(base::OpenFile(filename, O_RDONLY | O_CLOEXEC));
if (!fd) {
PERFETTO_DPLOG("Failed to open %s", filename.c_str());
return false;
}
char cmdline[512];
const size_t max_read_size = sizeof(cmdline) - 1;
ssize_t rd = read(*fd, cmdline, max_read_size);
if (rd == -1) {
PERFETTO_DPLOG("Failed to read %s", filename.c_str());
return false;
}
if (rd == 0) {
PERFETTO_DLOG("Empty cmdline for %" PRIdMAX ". Skipping.",
static_cast<intmax_t>(pid));
return false;
}
// In some buggy kernels (before http://bit.ly/37R7qwL) /proc/pid/cmdline is
// not NUL-terminated (see b/147438623). If we read < max_read_size bytes
// assume we are hitting the aforementioned kernel bug and terminate anyways.
const size_t rd_u = static_cast<size_t>(rd);
if (rd_u >= max_read_size && memchr(cmdline, '\0', rd_u) == nullptr) {
// We did not manage to read the first argument.
PERFETTO_DLOG("Overflow reading cmdline for %" PRIdMAX,
static_cast<intmax_t>(pid));
errno = EOVERFLOW;
return false;
}
cmdline[rd] = '\0';
char* cmdline_start = cmdline;
ssize_t size = NormalizeCmdLine(&cmdline_start, rd_u);
if (size == -1)
return false;
name->assign(cmdline_start, static_cast<size_t>(size));
return true;
}
void FindAllProfilablePids(std::set<pid_t>* pids) {
ForEachPid([pids](pid_t pid) {
if (pid == getpid())
return;
char filename_buf[128];
if (!GetProcFile(pid, "cmdline", filename_buf, sizeof(filename_buf)))
return;
struct stat statbuf;
// Check if we have permission to the process.
if (stat(filename_buf, &statbuf) == 0)
pids->emplace(pid);
});
}
void FindPidsForCmdlines(const std::vector<std::string>& cmdlines,
std::set<pid_t>* pids) {
ForEachPid([&cmdlines, pids](pid_t pid) {
if (pid == getpid())
return;
std::string process_cmdline;
process_cmdline.reserve(512);
GetCmdlineForPID(pid, &process_cmdline);
for (const std::string& cmdline : cmdlines) {
if (process_cmdline == cmdline)
pids->emplace(static_cast<pid_t>(pid));
}
});
}
base::Optional<std::string> ReadStatus(pid_t pid) {
std::string path = "/proc/" + std::to_string(pid) + "/status";
std::string status;
bool read_proc = base::ReadFile(path, &status);
if (!read_proc) {
PERFETTO_ELOG("Failed to read %s", path.c_str());
return base::nullopt;
}
return base::Optional<std::string>(status);
}
base::Optional<uint32_t> GetRssAnonAndSwap(const std::string& status) {
auto anon_rss = ParseProcStatusSize(status, "RssAnon:");
auto swap = ParseProcStatusSize(status, "VmSwap:");
if (anon_rss.has_value() && swap.has_value()) {
return *anon_rss + *swap;
}
return base::nullopt;
}
void RemoveUnderAnonThreshold(uint32_t min_size_kb, std::set<pid_t>* pids) {
for (auto it = pids->begin(); it != pids->end();) {
const pid_t pid = *it;
base::Optional<std::string> status = ReadStatus(pid);
base::Optional<uint32_t> rss_and_swap;
if (status)
rss_and_swap = GetRssAnonAndSwap(*status);
if (rss_and_swap && rss_and_swap < min_size_kb) {
PERFETTO_LOG("Removing pid %d from profiled set (anon: %d kB < %" PRIu32
")",
pid, *rss_and_swap, min_size_kb);
it = pids->erase(it);
} else {
++it;
}
}
}
} // namespace profiling
} // namespace perfetto
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