From 2a694596b548e60189ca7f9c08ff8dfba828ad7a Mon Sep 17 00:00:00 2001
From: topjohnwu <topjohnwu@gmail.com>
Date: Sat, 5 Dec 2020 10:23:49 -0800
Subject: [PATCH] Better error handling and logging

---
 native/jni/init/mount.cpp    |  1 +
 native/jni/init/raw_data.cpp |  8 +++++++-
 native/jni/utils/files.cpp   | 11 +++++++++--
 3 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/native/jni/init/mount.cpp b/native/jni/init/mount.cpp
index 9671f2263..e5e6fe0aa 100644
--- a/native/jni/init/mount.cpp
+++ b/native/jni/init/mount.cpp
@@ -346,6 +346,7 @@ void SARInit::early_mount() {
 		auto init = raw_data::mmap_ro("/init");
 		is_two_stage = init.contains("selinux_setup");
 	}
+	LOGD("is_two_stage: [%d]\n", is_two_stage);
 
 	if (!is_two_stage) {
 		// Make dev writable
diff --git a/native/jni/init/raw_data.cpp b/native/jni/init/raw_data.cpp
index 7f1d9bcc6..01ae06372 100644
--- a/native/jni/init/raw_data.cpp
+++ b/native/jni/init/raw_data.cpp
@@ -3,6 +3,8 @@
 using namespace std;
 
 int data_holder::patch(str_pairs list) {
+	if (buf == nullptr)
+		return 0;
 	int count = 0;
 	for (uint8_t *p = buf, *eof = buf + sz; p < eof; ++p) {
 		for (auto [from, to] : list) {
@@ -19,9 +21,13 @@ int data_holder::patch(str_pairs list) {
 }
 
 bool data_holder::contains(string_view pattern) {
+	if (buf == nullptr)
+		return false;
 	for (uint8_t *p = buf, *eof = buf + sz; p < eof; ++p) {
-		if (memcmp(p, pattern.data(), pattern.length() + 1) == 0)
+		if (memcmp(p, pattern.data(), pattern.length() + 1) == 0) {
+			LOGD("Found pattern [%s]\n", pattern.data());
 			return true;
+		}
 	}
 	return false;
 }
diff --git a/native/jni/utils/files.cpp b/native/jni/utils/files.cpp
index 098e487b4..685038a51 100644
--- a/native/jni/utils/files.cpp
+++ b/native/jni/utils/files.cpp
@@ -273,10 +273,17 @@ void fclone_attr(int src, int dest) {
 }
 
 void *__mmap(const char *filename, size_t *size, bool rw) {
+	int fd = xopen(filename, (rw ? O_RDWR : O_RDONLY) | O_CLOEXEC);
+	if (fd < 0) {
+		*size = 0;
+		return nullptr;
+	}
 	struct stat st;
 	void *buf;
-	int fd = xopen(filename, (rw ? O_RDWR : O_RDONLY) | O_CLOEXEC);
-	fstat(fd, &st);
+	if (fstat(fd, &st)) {
+		*size = 0;
+		return nullptr;
+	}
 	if (S_ISBLK(st.st_mode))
 		ioctl(fd, BLKGETSIZE64, size);
 	else