Add compressed ramdisk support

app-core/src/main/java/com/topjohnwu/magisk/tasks/MagiskInstaller.java

@@ -222,7 +222,8 @@ public abstract class MagiskInstaller {
                 Config.keepEnc, Config.keepVerity, srcBoot)).to(console, logs).exec().isSuccess())
             return false;
 
-        job = Shell.sh("mv bin/busybox busybox",
+        job = Shell.sh("./magiskboot --cleanup",
+                "mv bin/busybox busybox",
                 "rm -rf magisk.apk bin boot.img update-binary",
                 "cd /");
 

native/jni/core/init.cpp

@@ -30,7 +30,6 @@
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/mount.h>
-#include <sys/mman.h>
 #include <sys/sendfile.h>
 #include <sys/sysmacros.h>
 #include <functional>
@@ -40,6 +39,7 @@
 #include <magisk.h>
 #include <magiskpolicy.h>
 #include <selinux.h>
+#include <cpio.h>
 #include <utils.h>
 #include <flags.h>
 
@@ -320,6 +320,24 @@ static bool unxz(int fd, const uint8_t *buf, size_t size) {
 	return true;
 }
 
+static void decompress_ramdisk() {
+	constexpr char tmp[] = "tmp.cpio";
+	constexpr char ramdisk_xz[] = "ramdisk.cpio.xz";
+	if (access(ramdisk_xz, F_OK))
+		return;
+	uint8_t *buf;
+	size_t sz;
+	mmap_ro(ramdisk_xz, (void **) &buf, &sz);
+	int fd = open(tmp, O_WRONLY | O_CREAT | O_TRUNC | O_CLOEXEC);
+	unxz(fd, buf, sz);
+	munmap(buf, sz);
+	close(fd);
+	cpio_mmap cpio(tmp);
+	cpio.extract();
+	unlink(tmp);
+	unlink(ramdisk_xz);
+}
+
 static int dump_magisk(const char *path, mode_t mode) {
 	int fd = open(path, O_WRONLY | O_CREAT | O_TRUNC | O_CLOEXEC, mode);
 	if (fd < 0)
@@ -496,6 +514,8 @@ int main(int argc, char *argv[]) {
 		frm_rf(root);
 		excl_list = nullptr;
 	} else {
+		decompress_ramdisk();
+
 		// Revert original init binary
 		rename("/.backup/init", "/init");
 		rm_rf("/.backup");

native/jni/magiskboot/ramdisk.cpp

@@ -18,7 +18,7 @@ static const char *UNSUPPORT_LIST[] =
 
 static const char *MAGISK_LIST[] =
 		{ ".backup/.magisk", "init.magisk.rc",
-		  "overlay/init.magisk.rc", ramdisk_xz };
+		  "overlay/init.magisk.rc" };
 
 class magisk_cpio : public cpio_rw {
 public:
@@ -59,17 +59,21 @@ void magisk_cpio::patch(bool keepverity, bool keepforceencrypt) {
 	}
 }
 
-#define STOCK_BOOT       0x0
-#define MAGISK_PATCH     0x1
-#define UNSUPPORT_PATCH  0x2
+#define STOCK_BOOT        0
+#define MAGISK_PATCHED    1 << 0
+#define UNSUPPORTED_CPIO  1 << 1
+#define COMPRESSED_CPIO   1 << 2
 int magisk_cpio::test() {
+	if (exists(ramdisk_xz))
+		return MAGISK_PATCHED | COMPRESSED_CPIO;
+
 	for (auto file : UNSUPPORT_LIST)
 		if (exists(file))
-			return UNSUPPORT_PATCH;
+			return UNSUPPORTED_CPIO;
 
 	for (auto file : MAGISK_LIST)
 		if (exists(file))
-			return MAGISK_PATCH;
+			return MAGISK_PATCHED;
 
 	return STOCK_BOOT;
 }
@@ -108,6 +112,7 @@ char *magisk_cpio::sha1() {
 for (str = (char *) buf; str < (char *) buf + size; str = str += strlen(str) + 1)
 
 void magisk_cpio::restore() {
+	decompress();
 	char *file;
 	auto next = entries.begin();
 	decltype(next) cur;
@@ -218,8 +223,12 @@ void magisk_cpio::compress() {
 	encoder.set_out(make_unique<BufOutStream>());
 	output(encoder);
 	encoder.finalize();
+	auto backup = entries.extract(".backup");
+	auto config = entries.extract(".backup/.magisk");
 	entries.clear();
 	entries.insert(std::move(init));
+	entries.insert(std::move(backup));
+	entries.insert(std::move(config));
 	auto xz = new cpio_entry(ramdisk_xz, S_IFREG);
 	static_cast<BufOutStream *>(encoder.get_out())->release(xz->data, xz->filesize);
 	insert(xz);
@@ -230,6 +239,8 @@ void magisk_cpio::decompress() {
 	if (it == entries.end())
 		return;
 	fprintf(stderr, "Decompressing cpio [%s]\n", ramdisk_xz);
+	entries.erase(".backup");
+	entries.erase(".backup/.magisk");
 	LZMADecoder decoder;
 	decoder.set_out(make_unique<BufOutStream>());
 	decoder.write(it->second->data, it->second->filesize);

native/jni/utils/include/OutStream.h

@@ -3,6 +3,8 @@
 #include <unistd.h>
 #include <memory>
 
+#include "utils.h"
+
 class OutStream {
 public:
 	virtual bool write(const void *buf, size_t len) = 0;

scripts/boot_patch.sh

@@ -90,7 +90,8 @@ esac
 # Test patch status and do restore, after this section, ramdisk.cpio.orig is guaranteed to exist
 ui_print "- Checking ramdisk status"
 ./magiskboot --cpio ramdisk.cpio test
-case $? in
+STATUS=$?
+case $((STATUS & 3)) in
   0 )  # Stock boot
     ui_print "- Stock boot image detected"
     ui_print "- Backing up stock boot image"
@@ -128,6 +129,11 @@ echo "KEEPFORCEENCRYPT=$KEEPFORCEENCRYPT" >> config
 "backup ramdisk.cpio.orig" \
 "add 000 .backup/.magisk config"
 
+if [ $((STATUS & 4)) -ne 0 ]; then
+  ui_print "- Compressing ramdisk"
+  ./magiskboot --cpio ramdisk.cpio compress
+fi
+
 rm -f ramdisk.cpio.orig config
 
 ##########################################################################################
@@ -167,4 +173,5 @@ ui_print "- Repacking boot image"
 # Sign chromeos boot
 $CHROMEOS && sign_chromeos
 
-./magiskboot --cleanup
+# Reset any error code
+true

scripts/flash_script.sh

@@ -106,7 +106,15 @@ $IS64BIT && mv -f magiskinit64 magiskinit || rm -f magiskinit64
 . ./boot_patch.sh "$BOOTIMAGE"
 
 ui_print "- Flashing new boot image"
-flash_image new-boot.img "$BOOTIMAGE" || abort "! Insufficient partition size"
+
+if ! flash_image new-boot.img "$BOOTIMAGE"; then
+  ui_print "- Compressing ramdisk to fit in partition"
+  ./magiskboot --cpio ramdisk.cpio compress
+  ./magiskboot --repack "$BOOTIMAGE"
+  flash_image new-boot.img "$BOOTIMAGE" || abort "! Insufficient partition size"
+fi
+
+./magiskboot --cleanup
 rm -f new-boot.img
 
 if [ -f stock_boot* ]; then

scripts/util_functions.sh

@@ -256,9 +256,9 @@ flash_image() {
     CMD2="cat -"
   fi
   if [ -b "$2" ]; then
-    local s_size=`stat -c '%s' "$1"`
-    local t_size=`blockdev --getsize64 "$2"`
-    [ $s_size -gt $t_size ] && return 1
+    local img_sz=`stat -c '%s' "$1"`
+    local blk_sz=`blockdev --getsize64 "$2"`
+    [ $img_sz -gt $blk_sz ] && return 1
     eval $CMD1 | eval $CMD2 | cat - /dev/zero > "$2" 2>/dev/null
   else
     ui_print "- Not block device, storing image"