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Merge "Don't unmount /storage for early native processes"

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am: ee9554b2d9

Change-Id: I985413323a86816b392bd00211c550aef93328ae
This commit is contained in:
Jiyong Park 2019-03-08 17:55:15 -08:00 committed by android-build-merger
commit b5acb5bfba
2 changed files with 26 additions and 0 deletions
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3
Android.bp
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@ -152,6 +152,9 @@ cc_library_static {
shared_libs: [ shared_libs: [
"android.hardware.health.storage@1.0", "android.hardware.health.storage@1.0",
], ],
whole_static_libs: [
"com.android.sysprop.apex",
],
} }
cc_binary { cc_binary {

23
VolumeManager.cpp
View file

@ -33,6 +33,7 @@
#include <linux/kdev_t.h> #include <linux/kdev_t.h>
#include <ApexProperties.sysprop.h>
#include <android-base/logging.h> #include <android-base/logging.h>
#include <android-base/parseint.h> #include <android-base/parseint.h>
#include <android-base/properties.h> #include <android-base/properties.h>
@ -432,6 +433,8 @@ int VolumeManager::remountUid(uid_t uid, const std::string& mode) {
struct stat sb; struct stat sb;
pid_t child; pid_t child;
static bool apexUpdatable = android::sysprop::ApexProperties::updatable().value_or(false);
if (!(dir = opendir("/proc"))) { if (!(dir = opendir("/proc"))) {
PLOG(ERROR) << "Failed to opendir"; PLOG(ERROR) << "Failed to opendir";
return -1; return -1;
@ -476,6 +479,26 @@ int VolumeManager::remountUid(uid_t uid, const std::string& mode) {
goto next; goto next;
} }
if (apexUpdatable) {
std::string exeName;
// When ro.apex.bionic_updatable is set to true,
// some early native processes have mount namespaces that are different
// from that of the init. Therefore, above check can't filter them out.
// Since the propagation type of / is 'shared', unmounting /storage
// for the early native processes affects other processes including
// init. Filter out such processes by skipping if a process is a
// non-Java process whose UID is < AID_APP_START. (The UID condition
// is required to not filter out child processes spawned by apps.)
if (!android::vold::Readlinkat(pidFd, "exe", &exeName)) {
PLOG(WARNING) << "Failed to read exe name for " << de->d_name;
goto next;
}
if (!StartsWith(exeName, "/system/bin/app_process") && sb.st_uid < AID_APP_START) {
LOG(WARNING) << "Skipping due to native system process";
goto next;
}
}
// We purposefully leave the namespace open across the fork // We purposefully leave the namespace open across the fork
nsFd = openat(pidFd, "ns/mnt", O_RDONLY); // not O_CLOEXEC nsFd = openat(pidFd, "ns/mnt", O_RDONLY); // not O_CLOEXEC
if (nsFd < 0) { if (nsFd < 0) {