More complete support for fstab in dt

native/jni/init/getinfo.cpp

@@ -12,11 +12,9 @@
 
 using namespace std;
 
-#define DEFAULT_DT_DIR "/proc/device-tree/firmware/android"
-
 static void parse_cmdline(const std::function<void (std::string_view, const char *)> &fn) {
 	char cmdline[4096];
-	int fd = open("/proc/cmdline", O_RDONLY | O_CLOEXEC);
+	int fd = xopen("/proc/cmdline", O_RDONLY | O_CLOEXEC);
 	cmdline[read(fd, cmdline, sizeof(cmdline))] = '\0';
 	close(fd);
 
@@ -125,7 +123,10 @@ void load_kernel_info(cmdline *cmd) {
 		} else if (key == "enter_recovery") {
 			enter_recovery = value[0] == '1';
 		} else if (key == "androidboot.hardware") {
+			strcpy(cmd->hardware, value);
 			kirin = strstr(value, "kirin") || strstr(value, "hi3660") || strstr(value, "hi6250");
+		} else if (key == "androidboot.hardware.platform") {
+			strcpy(cmd->hardware_plat, value);
 		}
 	});
 
@@ -154,8 +155,11 @@ void load_kernel_info(cmdline *cmd) {
 	if (cmd->dt_dir[0] == '\0')
 		strcpy(cmd->dt_dir, DEFAULT_DT_DIR);
 
+	LOGD("Device info:\n");
 	LOGD("skip_initramfs=[%d]\n", cmd->skip_initramfs);
 	LOGD("force_normal_boot=[%d]\n", cmd->force_normal_boot);
 	LOGD("slot=[%s]\n", cmd->slot);
 	LOGD("dt_dir=[%s]\n", cmd->dt_dir);
+	LOGD("hardware=[%s]\n", cmd->hardware);
+	LOGD("hardware.platform=[%s]\n", cmd->hardware_plat);
 }

native/jni/init/init.hpp

@@ -4,6 +4,7 @@
 #include <unistd.h>
 #include <stdlib.h>
 #include <vector>
+#include <map>
 
 #include <logging.hpp>
 
@@ -11,7 +12,9 @@ struct cmdline {
 	bool skip_initramfs;
 	bool force_normal_boot;
 	char slot[3];
-	char dt_dir[128];
+	char dt_dir[64];
+	char hardware[32];
+	char hardware_plat[32];
 };
 
 struct raw_data {
@@ -31,6 +34,30 @@ struct raw_data {
 	}
 };
 
+struct fstab_entry {
+	std::string dev;
+	std::string mnt_point;
+	std::string type;
+	std::string mnt_flags;
+	std::string fsmgr_flags;
+
+	fstab_entry() = default;
+	fstab_entry(const fstab_entry &o) = delete;
+	fstab_entry(fstab_entry &&o) = default;
+};
+
+#define INIT_SOCKET "MAGISKINIT"
+#define DEFAULT_DT_DIR "/proc/device-tree/firmware/android"
+
+void load_kernel_info(cmdline *cmd);
+int dump_magisk(const char *path, mode_t mode);
+int magisk_proxy_main(int argc, char *argv[]);
+void setup_klog();
+void setup_tmp(const char *path, const raw_data &self, const raw_data &config);
+
+using str_pairs = std::initializer_list<std::pair<std::string_view, std::string_view>>;
+int raw_data_patch(void *addr, size_t sz, str_pairs list);
+
 /***************
  * Base classes
  ***************/
@@ -52,6 +79,8 @@ public:
 	cmd(cmd), argv(argv), mount_list{"/sys", "/proc"} {}
 	virtual ~BaseInit() = default;
 	virtual void start() = 0;
+	void read_dt_fstab(std::map<std::string_view, fstab_entry> &fstab);
+	void dt_early_mount();
 };
 
 class MagiskInit : public BaseInit {
@@ -158,11 +187,3 @@ public:
 		exec_init();
 	}
 };
-
-#define INIT_SOCKET "MAGISKINIT"
-
-void load_kernel_info(cmdline *cmd);
-int dump_magisk(const char *path, mode_t mode);
-int magisk_proxy_main(int argc, char *argv[]);
-void setup_klog();
-void setup_tmp(const char *path, const raw_data &self, const raw_data &config);

native/jni/init/mount.cpp

@@ -1,6 +1,7 @@
 #include <sys/sysmacros.h>
 #include <string.h>
 #include <stdio.h>
+#include <libgen.h>
 #include <vector>
 
 #include <utils.hpp>
@@ -21,10 +22,6 @@ struct devinfo {
 
 static vector<devinfo> dev_list;
 
-static char partname[32];
-static char fstype[32];
-static char block_dev[64];
-
 static void parse_device(devinfo *dev, const char *uevent) {
 	dev->partname[0] = '\0';
 	parse_prop_file(uevent, [=](string_view key, string_view value) -> bool {
@@ -55,6 +52,11 @@ static void collect_devices() {
 	}
 }
 
+static struct {
+	char partname[32];
+	char block_dev[64];
+} blk_info;
+
 static int64_t setup_block(bool write_block = true) {
 	if (dev_list.empty())
 		collect_devices();
@@ -63,13 +65,13 @@ static int64_t setup_block(bool write_block = true) {
 
 	for (int tries = 0; tries < 3; ++tries) {
 		for (auto &dev : dev_list) {
-			if (strcasecmp(dev.partname, partname) == 0) {
+			if (strcasecmp(dev.partname, blk_info.partname) == 0) {
 				if (write_block) {
-					sprintf(block_dev, "/dev/block/%s", dev.devname);
+					sprintf(blk_info.block_dev, "/dev/block/%s", dev.devname);
 				}
-				LOGD("Found %s: [%s] (%d, %d)\n", dev.partname, dev.devname, dev.major, dev.minor);
+				LOGD("Setup %s: [%s] (%d, %d)\n", dev.partname, dev.devname, dev.major, dev.minor);
 				dev_t rdev = makedev(dev.major, dev.minor);
-				mknod(block_dev, S_IFBLK | 0600, rdev);
+				mknod(blk_info.block_dev, S_IFBLK | 0600, rdev);
 				return rdev;
 			}
 		}
@@ -90,35 +92,69 @@ static bool is_lnk(const char *name) {
 	return S_ISLNK(st.st_mode);
 }
 
-static bool read_dt_fstab(cmdline *cmd, const char *name) {
+static string rtrim(string &&str) {
-	char path[128];
+	// Trim space, newline, and null byte from end of string
-	int fd;
+	while (memchr(" \n\r", str[str.length() - 1], 4))
-	sprintf(path, "%s/fstab/%s/dev", cmd->dt_dir, name);
+		str.pop_back();
-	if ((fd = open(path, O_RDONLY | O_CLOEXEC)) >= 0) {
+	return std::move(str);
-		read(fd, path, sizeof(path));
-		close(fd);
-		path[strcspn(path, "\r\n")] = '\0';
-		// Some custom treble use different names, so use what we read
-		char *part = rtrim(strrchr(path, '/') + 1);
-		sprintf(partname, "%s%s", part, strend(part, cmd->slot) ? cmd->slot : "");
-		sprintf(path, "%s/fstab/%s/type", cmd->dt_dir, name);
-		if ((fd = xopen(path, O_RDONLY | O_CLOEXEC)) >= 0) {
-			read(fd, fstype, 32);
-			close(fd);
-			fstype[strcspn(fstype, "\r\n")] = '\0';
-			return true;
-		}
-	}
-	return false;
 }
 
-#define mount_root(name) \
+#define read_info(val) \
-if (!is_lnk("/" #name) && read_dt_fstab(cmd, #name)) { \
+if (access(#val, F_OK) == 0) {\
-	LOGD("Early mount " #name "\n"); \
+	entry.val = rtrim(full_read(#val)); \
-	setup_block(); \
+}
-	xmkdir("/" #name, 0755); \
+
-	xmount(block_dev, "/" #name, fstype, MS_RDONLY, nullptr); \
+void BaseInit::read_dt_fstab(map<string_view, fstab_entry> &fstab) {
-	mount_list.emplace_back("/" #name); \
+	if (access(cmd->dt_dir, F_OK) != 0)
+		return;
+	chdir(cmd->dt_dir);
+	run_finally cr([]{ chdir("/"); });
+
+	if (access("fstab", F_OK) != 0)
+		return;
+	chdir("fstab");
+
+	auto dir = xopen_dir(".");
+	for (dirent *dp; (dp = xreaddir(dir.get()));) {
+		if (dp->d_type != DT_DIR)
+			continue;
+		chdir(dp->d_name);
+		run_finally f([]{ chdir(".."); });
+
+		if (access("status", F_OK) == 0) {
+			auto status = rtrim(full_read("status"));
+			if (status != "okay" && status != "ok")
+				continue;
+		}
+
+		fstab_entry entry;
+
+		read_info(dev);
+		read_info(mnt_point) else {
+			entry.mnt_point = "/";
+			entry.mnt_point += dp->d_name;
+		}
+		read_info(type);
+		read_info(mnt_flags);
+		read_info(fsmgr_flags);
+
+		fstab.emplace(entry.mnt_point, std::move(entry));
+	}
+}
+
+void BaseInit::dt_early_mount() {
+	map<string_view, fstab_entry> fstab;
+	read_dt_fstab(fstab);
+	for (const auto &[_, entry] : fstab) {
+		if (is_lnk(entry.mnt_point.data()))
+			continue;
+		// Derive partname from dev
+		sprintf(blk_info.partname, "%s%s", basename(entry.dev.data()), cmd->slot);
+		setup_block();
+		xmkdir(entry.mnt_point.data(), 0755);
+		xmount(blk_info.block_dev, entry.mnt_point.data(), entry.type.data(), MS_RDONLY, nullptr);
+		mount_list.push_back(entry.mnt_point);
+	}
 }
 
 static void switch_root(const string &path) {
@@ -152,17 +188,17 @@ static void switch_root(const string &path) {
 
 static void mount_persist(const char *dev_base, const char *mnt_base) {
 	string mnt_point = mnt_base + "/persist"s;
-	strcpy(partname, "persist");
+	strcpy(blk_info.partname, "persist");
-	xrealpath(dev_base, block_dev);
+	xrealpath(dev_base, blk_info.block_dev);
-	char *s = block_dev + strlen(block_dev);
+	char *s = blk_info.block_dev + strlen(blk_info.block_dev);
 	strcpy(s, "/persist");
 	if (setup_block(false) < 0) {
 		// Fallback to cache
-		strcpy(partname, "cache");
+		strcpy(blk_info.partname, "cache");
 		strcpy(s, "/cache");
 		if (setup_block(false) < 0) {
 			// Try NVIDIA's BS
-			strcpy(partname, "CAC");
+			strcpy(blk_info.partname, "CAC");
 			if (setup_block(false) < 0)
 				return;
 		}
@@ -170,19 +206,16 @@ static void mount_persist(const char *dev_base, const char *mnt_base) {
 		mnt_point = mnt_base + "/cache"s;
 	}
 	xmkdir(mnt_point.data(), 0755);
-	xmount(block_dev, mnt_point.data(), "ext4", 0, nullptr);
+	xmount(blk_info.block_dev, mnt_point.data(), "ext4", 0, nullptr);
 }
 
 void RootFSInit::early_mount() {
 	full_read("/init", self.buf, self.sz);
 
-	LOGD("Reverting /init\n");
+	LOGD("Restoring /init\n");
 	rename("/.backup/init", "/init");
 
-	mount_root(system);
+	dt_early_mount();
-	mount_root(vendor);
-	mount_root(product);
-	mount_root(odm);
 
 	xmkdir("/dev/mnt", 0755);
 	mount_persist("/dev/block", "/dev/mnt");
@@ -201,12 +234,12 @@ void SARBase::backup_files() {
 
 void SARBase::mount_system_root() {
 	LOGD("Early mount system_root\n");
-	sprintf(partname, "system%s", cmd->slot);
+	sprintf(blk_info.partname, "system%s", cmd->slot);
-	strcpy(block_dev, "/dev/root");
+	strcpy(blk_info.block_dev, "/dev/root");
 	auto dev = setup_block(false);
 	if (dev < 0) {
 		// Try NVIDIA naming scheme
-		strcpy(partname, "APP");
+		strcpy(blk_info.partname, "APP");
 		dev = setup_block(false);
 		if (dev < 0) {
 			// We don't really know what to do at this point...
@@ -230,9 +263,7 @@ void SARInit::early_mount() {
 	mount_system_root();
 	switch_root("/system_root");
 
-	mount_root(vendor);
+	dt_early_mount();
-	mount_root(product);
-	mount_root(odm);
 }
 
 void SARFirstStageInit::early_mount() {
@@ -262,15 +293,12 @@ void BaseInit::cleanup() {
 }
 
 static void patch_socket_name(const char *path) {
+	char rstr[16];
+	gen_rand_str(rstr, sizeof(rstr));
 	char *buf;
 	size_t size;
 	mmap_rw(path, buf, size);
-	for (int i = 0; i < size; ++i) {
+	raw_data_patch(buf, size, { make_pair(MAIN_SOCKET, rstr) });
-		if (memcmp(buf + i, MAIN_SOCKET, sizeof(MAIN_SOCKET)) == 0) {
-			gen_rand_str(buf + i, 16);
-			i += sizeof(MAIN_SOCKET);
-		}
-	}
 	munmap(buf, size);
 }
 

native/jni/init/rootdir.cpp

@@ -81,19 +81,28 @@ static void load_overlay_rc(const char *overlay) {
 	}
 }
 
+int raw_data_patch(void *addr, size_t sz, str_pairs list) {
+	int count = 0;
+	for (uint8_t *p = (uint8_t *)addr, *eof = (uint8_t *)addr + sz; p < eof; ++p) {
+		for (auto &[from, to] : list) {
+			if (memcmp(p, from.data(), from.length() + 1) == 0) {
+				LOGD("Replace [%s] -> [%s]\n", from.data(), to.data());
+				memset(p, 0, from.length());
+				memcpy(p, to.data(), to.length());
+				++count;
+				p += from.length();
+			}
+		}
+	}
+	return count;
+}
+
 void RootFSInit::setup_rootfs() {
 	if (patch_sepolicy("/sepolicy")) {
 		char *addr;
 		size_t size;
 		mmap_rw("/init", addr, size);
-		for (char *p = addr; p < addr + size; ++p) {
+		raw_data_patch(addr, size, {make_pair(SPLIT_PLAT_CIL, "xxx")});
-			if (memcmp(p, SPLIT_PLAT_CIL, sizeof(SPLIT_PLAT_CIL)) == 0) {
-				// Force init to load /sepolicy
-				LOGD("Remove from init: " SPLIT_PLAT_CIL "\n");
-				memset(p, 'x', sizeof(SPLIT_PLAT_CIL) - 1);
-				break;
-			}
-		}
 		munmap(addr, size);
 	}
 
@@ -259,43 +268,26 @@ void SARBase::patch_rootdir() {
 
 	// Patch init
 	raw_data init;
-	bool redirect = false;
 	int src = xopen("/init", O_RDONLY | O_CLOEXEC);
 	fd_full_read(src, init.buf, init.sz);
-	for (uint8_t *p = init.buf, *eof = init.buf + init.sz; p < eof;) {
+	int patch_count = raw_data_patch(init.buf, init.sz, {
-		if (memcmp(p, SPLIT_PLAT_CIL, sizeof(SPLIT_PLAT_CIL)) == 0) {
+		make_pair(SPLIT_PLAT_CIL, "xxx"), /* Force loading monolithic sepolicy */
-			LOGD("Remove from init: " SPLIT_PLAT_CIL "\n");
+		make_pair(MONOPOLICY, sepol)      /* Redirect /sepolicy to custom path */
-			memset(p, 'x', sizeof(SPLIT_PLAT_CIL) - 1);
+	});
-			p += sizeof(SPLIT_PLAT_CIL);
-		} else if (memcmp(p, MONOPOLICY, sizeof(MONOPOLICY)) == 0) {
-			LOGD("Patch init [" MONOPOLICY "] -> [%s]\n", sepol);
-			strcpy(reinterpret_cast<char *>(p), sepol);
-			redirect = true;
-			p += sizeof(MONOPOLICY);
-		} else {
-			++p;
-		}
-	}
 	xmkdir(ROOTOVL, 0);
-	int dest = xopen(ROOTOVL "/init", O_CREAT | O_WRONLY | O_CLOEXEC);
+	int dest = xopen(ROOTOVL "/init", O_CREAT | O_WRONLY | O_CLOEXEC, 0);
 	xwrite(dest, init.buf, init.sz);
 	fclone_attr(src, dest);
 	close(src);
 	close(dest);
 
-	if (!redirect) {
+	if (patch_count != 2 && access(LIBSELINUX, F_OK) == 0) {
 		// init is dynamically linked, need to patch libselinux
 		raw_data lib;
 		full_read(LIBSELINUX, lib.buf, lib.sz);
-		for (uint8_t *p = lib.buf, *eof = lib.buf + lib.sz; p < eof; ++p) {
+		raw_data_patch(lib.buf, lib.sz, {make_pair(MONOPOLICY, sepol)});
-			if (memcmp(p, MONOPOLICY, sizeof(MONOPOLICY)) == 0) {
-				LOGD("Patch libselinux.so [" MONOPOLICY "] -> [%s]\n", sepol);
-				strcpy(reinterpret_cast<char *>(p), sepol);
-				break;
-			}
-		}
 		xmkdirs(dirname(ROOTOVL LIBSELINUX), 0755);
-		dest = xopen(ROOTOVL LIBSELINUX, O_CREAT | O_WRONLY | O_CLOEXEC);
+		dest = xopen(ROOTOVL LIBSELINUX, O_CREAT | O_WRONLY | O_CLOEXEC, 0);
 		xwrite(dest, lib.buf, lib.sz);
 		close(dest);
 		clone_attr(LIBSELINUX, ROOTOVL LIBSELINUX);

native/jni/utils/files.cpp

@@ -302,11 +302,10 @@ void full_read(const char *filename, void **buf, size_t *size) {
 }
 
 string fd_full_read(int fd) {
+	char buf[4096];
 	string str;
-	auto len = lseek(fd, 0, SEEK_END);
+	for (ssize_t len; (len = xread(fd, buf, sizeof(buf))) > 0;)
-	str.resize(len);
+		str.insert(str.end(), buf, buf + len);
-	lseek(fd, 0, SEEK_SET);
-	xxread(fd, str.data(), len);
 	return str;
 }
 

native/jni/utils/misc.cpp

@@ -164,14 +164,6 @@ bool ends_with(const std::string_view &s1, const std::string_view &s2) {
 	return l1 < l2 ? false : s1.compare(l1 - l2, l2, s2) == 0;
 }
 
-char *rtrim(char *str) {
-	int len = strlen(str);
-	while (len > 0 && str[len - 1] == ' ')
-		--len;
-	str[len] = '\0';
-	return str;
-}
-
 /*
  * Bionic's atoi runs through strtol().
  * Use our own implementation for faster conversion.

native/jni/utils/misc.hpp

@@ -97,7 +97,6 @@ bool ends_with(const std::string_view &s1, const std::string_view &s2);
 int fork_dont_care();
 int fork_no_zombie();
 int strend(const char *s1, const char *s2);
-char *rtrim(char *str);
 void init_argv0(int argc, char **argv);
 void set_nice_name(const char *name);
 uint32_t binary_gcd(uint32_t u, uint32_t v);