run-as: add shared app gid in supplementary groups.
This is to read profile guide compiled oat files of debuggable apps, which is
needed by simpleperf for profiling.
Bug: none
Test: run run-as manually.
Change-Id: I8ec8897b882be650f02124413c7d20ed8b1b444b
diff --git a/run-as/run-as.cpp b/run-as/run-as.cpp
index f49bdf7..8752eef 100644
--- a/run-as/run-as.cpp
+++ b/run-as/run-as.cpp
@@ -26,6 +26,7 @@
#include <unistd.h>
#include <string>
+#include <vector>
#include <libminijail.h>
#include <scoped_minijail.h>
@@ -131,6 +132,25 @@
return check_directory(data_path, uid);
}
+std::vector<gid_t> get_supplementary_gids(uid_t userAppId) {
+ std::vector<gid_t> gids;
+ int size = getgroups(0, &gids[0]);
+ if (size < 0) {
+ error(1, errno, "getgroups failed");
+ }
+ gids.resize(size);
+ size = getgroups(size, &gids[0]);
+ if (size != static_cast<int>(gids.size())) {
+ error(1, errno, "getgroups failed");
+ }
+ // Profile guide compiled oat files (like /data/app/xxx/oat/arm64/base.odex) are not readable
+ // worldwide (DEXOPT_PUBLIC flag isn't set). To support reading them (needed by simpleperf for
+ // profiling), add shared app gid to supplementary groups.
+ gid_t shared_app_gid = userAppId % AID_USER_OFFSET - AID_APP_START + AID_SHARED_GID_START;
+ gids.push_back(shared_app_gid);
+ return gids;
+}
+
int main(int argc, char* argv[]) {
// Check arguments.
if (argc < 2) {
@@ -210,10 +230,11 @@
// same time to avoid nasty surprises.
uid_t uid = userAppId;
uid_t gid = userAppId;
+ std::vector<gid_t> supplementary_gids = get_supplementary_gids(userAppId);
ScopedMinijail j(minijail_new());
minijail_change_uid(j.get(), uid);
minijail_change_gid(j.get(), gid);
- minijail_keep_supplementary_gids(j.get());
+ minijail_set_supplementary_gids(j.get(), supplementary_gids.size(), supplementary_gids.data());
minijail_enter(j.get());
std::string seinfo = std::string(info.seinfo) + ":fromRunAs";
