libprocinfo: add functions reading process map file.
Add test and benchmark.
Also switch libbacktrace, libunwindstack, libmemunreachable
to use libprocinfo for map file reading.
The benchmark shows using libprocinfo speeds up map file reading
in libbacktrace and libunwindstack 18% - 36% on walleye.
Bug: http://b/79118393
Test: run procinfo_test.
Test: run libunwindstack_test.
Test: run libbacktrace_test.
Test: run memunreachable_test.
Change-Id: Icf281c352f4103fc8d4ba6732c5c07b943330ca1
diff --git a/libunwindstack/Maps.cpp b/libunwindstack/Maps.cpp
index e1a1a71..bb682ea 100644
--- a/libunwindstack/Maps.cpp
+++ b/libunwindstack/Maps.cpp
@@ -24,6 +24,7 @@
#include <unistd.h>
#include <android-base/unique_fd.h>
+#include <procinfo/process_map.h>
#include <algorithm>
#include <cctype>
@@ -57,150 +58,16 @@
return nullptr;
}
-// Assumes that line does not end in '\n'.
-static MapInfo* InternalParseLine(const char* line) {
- // Do not use a sscanf implementation since it is not performant.
-
- // Example linux /proc/<pid>/maps lines:
- // 6f000000-6f01e000 rwxp 00000000 00:0c 16389419 /system/lib/libcomposer.so
- char* str;
- const char* old_str = line;
- uint64_t start = strtoull(old_str, &str, 16);
- if (old_str == str || *str++ != '-') {
- return nullptr;
- }
-
- old_str = str;
- uint64_t end = strtoull(old_str, &str, 16);
- if (old_str == str || !std::isspace(*str++)) {
- return nullptr;
- }
-
- while (std::isspace(*str)) {
- str++;
- }
-
- // Parse permissions data.
- if (*str == '\0') {
- return nullptr;
- }
- uint16_t flags = 0;
- if (*str == 'r') {
- flags |= PROT_READ;
- } else if (*str != '-') {
- return nullptr;
- }
- str++;
- if (*str == 'w') {
- flags |= PROT_WRITE;
- } else if (*str != '-') {
- return nullptr;
- }
- str++;
- if (*str == 'x') {
- flags |= PROT_EXEC;
- } else if (*str != '-') {
- return nullptr;
- }
- str++;
- if (*str != 'p' && *str != 's') {
- return nullptr;
- }
- str++;
-
- if (!std::isspace(*str++)) {
- return nullptr;
- }
-
- old_str = str;
- uint64_t offset = strtoull(old_str, &str, 16);
- if (old_str == str || !std::isspace(*str)) {
- return nullptr;
- }
-
- // Ignore the 00:00 values.
- old_str = str;
- (void)strtoull(old_str, &str, 16);
- if (old_str == str || *str++ != ':') {
- return nullptr;
- }
- if (std::isspace(*str)) {
- return nullptr;
- }
-
- // Skip the inode.
- old_str = str;
- (void)strtoull(str, &str, 16);
- if (old_str == str || !std::isspace(*str++)) {
- return nullptr;
- }
-
- // Skip decimal digit.
- old_str = str;
- (void)strtoull(old_str, &str, 10);
- if (old_str == str || (!std::isspace(*str) && *str != '\0')) {
- return nullptr;
- }
-
- while (std::isspace(*str)) {
- str++;
- }
- if (*str == '\0') {
- return new MapInfo(start, end, offset, flags, "");
- }
-
- // Save the name data.
- std::string name(str);
-
- // Mark a device map in /dev/ and not in /dev/ashmem/ specially.
- if (name.substr(0, 5) == "/dev/" && name.substr(5, 7) != "ashmem/") {
- flags |= MAPS_FLAGS_DEVICE_MAP;
- }
- return new MapInfo(start, end, offset, flags, name);
-}
-
bool Maps::Parse() {
- int fd = open(GetMapsFile().c_str(), O_RDONLY | O_CLOEXEC);
- if (fd == -1) {
- return false;
- }
-
- bool return_value = true;
- char buffer[2048];
- size_t leftover = 0;
- while (true) {
- ssize_t bytes = read(fd, &buffer[leftover], 2048 - leftover);
- if (bytes == -1) {
- return_value = false;
- break;
- }
- if (bytes == 0) {
- break;
- }
- bytes += leftover;
- char* line = buffer;
- while (bytes > 0) {
- char* newline = static_cast<char*>(memchr(line, '\n', bytes));
- if (newline == nullptr) {
- memmove(buffer, line, bytes);
- break;
- }
- *newline = '\0';
-
- MapInfo* map_info = InternalParseLine(line);
- if (map_info == nullptr) {
- return_value = false;
- break;
- }
- maps_.push_back(map_info);
-
- bytes -= newline - line + 1;
- line = newline + 1;
- }
- leftover = bytes;
- }
- close(fd);
- return return_value;
+ return android::procinfo::ReadMapFile(
+ GetMapsFile(),
+ [&](uint64_t start, uint64_t end, uint16_t flags, uint64_t pgoff, const char* name) {
+ // Mark a device map in /dev/ and not in /dev/ashmem/ specially.
+ if (strncmp(name, "/dev/", 5) == 0 && strncmp(name + 5, "ashmem/", 7) != 0) {
+ flags |= unwindstack::MAPS_FLAGS_DEVICE_MAP;
+ }
+ maps_.push_back(new MapInfo(start, end, pgoff, flags, name));
+ });
}
void Maps::Add(uint64_t start, uint64_t end, uint64_t offset, uint64_t flags,
@@ -222,26 +89,16 @@
}
bool BufferMaps::Parse() {
- const char* start_of_line = buffer_;
- do {
- std::string line;
- const char* end_of_line = strchr(start_of_line, '\n');
- if (end_of_line == nullptr) {
- line = start_of_line;
- } else {
- line = std::string(start_of_line, end_of_line - start_of_line);
- end_of_line++;
- }
-
- MapInfo* map_info = InternalParseLine(line.c_str());
- if (map_info == nullptr) {
- return false;
- }
- maps_.push_back(map_info);
-
- start_of_line = end_of_line;
- } while (start_of_line != nullptr && *start_of_line != '\0');
- return true;
+ std::string content(buffer_);
+ return android::procinfo::ReadMapFileContent(
+ &content[0],
+ [&](uint64_t start, uint64_t end, uint16_t flags, uint64_t pgoff, const char* name) {
+ // Mark a device map in /dev/ and not in /dev/ashmem/ specially.
+ if (strncmp(name, "/dev/", 5) == 0 && strncmp(name + 5, "ashmem/", 7) != 0) {
+ flags |= unwindstack::MAPS_FLAGS_DEVICE_MAP;
+ }
+ maps_.push_back(new MapInfo(start, end, pgoff, flags, name));
+ });
}
const std::string RemoteMaps::GetMapsFile() const {