From 02ea3ca5254c9c9ff9edeaa59063af0e8175e536 Mon Sep 17 00:00:00 2001
From: topjohnwu <topjohnwu@gmail.com>
Date: Sun, 25 Oct 2020 06:25:42 -0700
Subject: [PATCH] Headers doesn't always occupy 1 page

---
 native/jni/magiskboot/bootimg.cpp | 6 +++---
 native/jni/magiskboot/bootimg.hpp | 3 +++
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/native/jni/magiskboot/bootimg.cpp b/native/jni/magiskboot/bootimg.cpp
index cf1a93ee7..7a1047f55 100644
--- a/native/jni/magiskboot/bootimg.cpp
+++ b/native/jni/magiskboot/bootimg.cpp
@@ -294,7 +294,7 @@ void boot_img::parse_image(uint8_t *addr, format_t type) {
 
 	hdr->print();
 
-	size_t off = hdr->page_size();
+	size_t off = hdr->hdr_space();
 	hdr_addr = addr;
 	get_block(kernel);
 	get_block(ramdisk);
@@ -474,9 +474,9 @@ void repack(const char* src_img, const char* out_img, bool skip_comp) {
 		restore_buf(fd, boot.map_addr, ACCLAIM_PRE_HEADER_SZ);
 	}
 
-	// Copy a page for header
+	// Copy header
 	off.header = lseek(fd, 0, SEEK_CUR);
-	restore_buf(fd, boot.hdr_addr, boot.hdr->page_size());
+	restore_buf(fd, boot.hdr_addr, boot.hdr->hdr_space());
 
 	// kernel
 	off.kernel = lseek(fd, 0, SEEK_CUR);
diff --git a/native/jni/magiskboot/bootimg.hpp b/native/jni/magiskboot/bootimg.hpp
index 6b35eb70f..9be673b33 100644
--- a/native/jni/magiskboot/bootimg.hpp
+++ b/native/jni/magiskboot/bootimg.hpp
@@ -243,6 +243,7 @@ struct dyn_img_hdr {
 	}
 
 	virtual size_t hdr_size() = 0;
+	virtual size_t hdr_space() { return page_size(); }
 
 	const void *raw_hdr() const { return raw; }
 	void print();
@@ -367,6 +368,8 @@ struct dyn_img_vnd_v3 : public dyn_img_hdr {
 	impl_val(header_size)
 	impl_val(dtb_size)
 
+	size_t hdr_space() override { auto sz = page_size(); return do_align(hdr_size(), sz); }
+
 	// Make API compatible
 	char *extra_cmdline() override { return &vnd->cmdline[BOOT_ARGS_SIZE]; }
 };