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/ProcessMappings.cpp b/ProcessMappings.cpp
index 9a06870..701ce16 100644
--- a/ProcessMappings.cpp
+++ b/ProcessMappings.cpp
@@ -14,21 +14,30 @@
* limitations under the License.
*/
+#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <string.h>
#include <unistd.h>
#include <android-base/unique_fd.h>
+#include <procinfo/process_map.h>
-#include "LineBuffer.h"
#include "ProcessMappings.h"
-#include "log.h"
namespace android {
-// This function is not re-entrant since it uses a static buffer for
-// the line data.
+struct ReadMapCallback {
+ ReadMapCallback(allocator::vector<Mapping>& mappings) : mappings_(mappings) {}
+
+ void operator()(uint64_t start, uint64_t end, uint16_t flags, uint64_t, const char* name) const {
+ mappings_.emplace_back(start, end, flags & PROT_READ, flags & PROT_WRITE, flags & PROT_EXEC,
+ name);
+ }
+
+ allocator::vector<Mapping>& mappings_;
+};
+
bool ProcessMappings(pid_t pid, allocator::vector<Mapping>& mappings) {
char map_buffer[1024];
snprintf(map_buffer, sizeof(map_buffer), "/proc/%d/maps", pid);
@@ -36,35 +45,13 @@
if (fd == -1) {
return false;
}
-
- LineBuffer line_buf(fd, map_buffer, sizeof(map_buffer));
- char* line;
- size_t line_len;
- while (line_buf.GetLine(&line, &line_len)) {
- int name_pos;
- char perms[5];
- Mapping mapping{};
- if (sscanf(line, "%" SCNxPTR "-%" SCNxPTR " %4s %*x %*x:%*x %*d %n", &mapping.begin,
- &mapping.end, perms, &name_pos) == 3) {
- if (perms[0] == 'r') {
- mapping.read = true;
- }
- if (perms[1] == 'w') {
- mapping.write = true;
- }
- if (perms[2] == 'x') {
- mapping.execute = true;
- }
- if (perms[3] == 'p') {
- mapping.priv = true;
- }
- if ((size_t)name_pos < line_len) {
- strlcpy(mapping.name, line + name_pos, sizeof(mapping.name));
- }
- mappings.emplace_back(mapping);
- }
+ allocator::string content(mappings.get_allocator());
+ ssize_t n;
+ while ((n = TEMP_FAILURE_RETRY(read(fd, map_buffer, sizeof(map_buffer)))) > 0) {
+ content.append(map_buffer, n);
}
- return true;
+ ReadMapCallback callback(mappings);
+ return android::procinfo::ReadMapFileContent(&content[0], callback);
}
} // namespace android