[PATCH u-boot-marvell 24/29] tools: kwboot: Round up header size to 128 B when patching

["Marek Behún" <marek.behun@nic.cz>]

From: Pali Rohár <pali@kernel.org>

The beginning of image data must be sent in a separate xmodem block;
the block must not contain end of header with the beginning of data.

Therefore we need to ensure that the image header size is a multiple of
xmodem block size (which is 128 B).

Read the file into a malloc()ed buffer of enough size instead of
mmap()ing it. (If we are going to move the data, most of the pages will
be dirty anyway.) Then move the payload if header size needs to be
increased.

Signed-off-by: Pali Rohár <pali@kernel.org>
[ refactored ]
Signed-off-by: Marek Behún <marek.behun@nic.cz>
---
 tools/kwboot.c | 91 +++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 79 insertions(+), 12 deletions(-)

diff --git a/tools/kwboot.c b/tools/kwboot.c
index 1481735346..6d7d812416 100644
--- a/tools/kwboot.c
+++ b/tools/kwboot.c
@@ -25,7 +25,6 @@
 #include <stdint.h>
 #include <termios.h>
 #include <time.h>
-#include <sys/mman.h>
 #include <sys/stat.h>
 
 /*
@@ -689,11 +688,12 @@ out:
 }
 
 static void *
-kwboot_mmap_image(const char *path, size_t *size)
+kwboot_read_image(const char *path, size_t *size, size_t reserve)
 {
 	int rc, fd;
 	struct stat st;
 	void *img;
+	off_t tot;
 
 	rc = -1;
 	img = NULL;
@@ -706,17 +706,30 @@ kwboot_mmap_image(const char *path, size_t *size)
 	if (rc)
 		goto out;
 
-	img = mmap(NULL, st.st_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
-	if (img == MAP_FAILED) {
-		img = NULL;
+	img = malloc(st.st_size + reserve);
+	if (!img)
 		goto out;
+
+	tot = 0;
+	while (tot < st.st_size) {
+		ssize_t rd = read(fd, img + tot, st.st_size - tot);
+
+		if (rd < 0)
+			goto out;
+
+		tot += rd;
+
+		if (!rd && tot < st.st_size) {
+			errno = EIO;
+			goto out;
+		}
 	}
 
 	rc = 0;
 	*size = st.st_size;
 out:
 	if (rc && img) {
-		munmap(img, st.st_size);
+		free(img);
 		img = NULL;
 	}
 	if (fd >= 0)
@@ -752,8 +765,41 @@ kwboot_img_is_secure(void *img)
 	return 0;
 }
 
+static void
+kwboot_img_grow_hdr(void *img, size_t *size, size_t grow)
+{
+	uint32_t hdrsz, datasz, srcaddr;
+	struct main_hdr_v1 *hdr = img;
+	uint8_t *data;
+
+	srcaddr = le32_to_cpu(hdr->srcaddr);
+
+	hdrsz = kwbheader_size(hdr);
+	data = (uint8_t *)img + srcaddr;
+	datasz = *size - srcaddr;
+
+	/* only move data if there is not enough space */
+	if (hdrsz + grow > srcaddr) {
+		size_t need = hdrsz + grow - srcaddr;
+
+		/* move data by enough bytes */
+		memmove(data + need, data, datasz);
+
+		hdr->srcaddr = cpu_to_le32(srcaddr + need);
+		*size += need;
+	}
+
+	if (kwbimage_version(img) == 1) {
+		struct main_hdr_v1 *hdr = img;
+
+		hdrsz += grow;
+		hdr->headersz_msb = hdrsz >> 16;
+		hdr->headersz_lsb = cpu_to_le16(hdrsz & 0xffff);
+	}
+}
+
 static int
-kwboot_img_patch_hdr(void *img, size_t size)
+kwboot_img_patch_hdr(void *img, size_t *size)
 {
 	int rc;
 	struct main_hdr_v1 *hdr;
@@ -767,7 +813,7 @@ kwboot_img_patch_hdr(void *img, size_t size)
 	rc = -1;
 	hdr = img;
 
-	if (size < hdrsz) {
+	if (*size < hdrsz) {
 		errno = EINVAL;
 		goto out;
 	}
@@ -781,7 +827,7 @@ kwboot_img_patch_hdr(void *img, size_t size)
 
 	hdrsz = kwbheader_size(hdr);
 
-	if (size < hdrsz) {
+	if (*size < hdrsz) {
 		errno = EINVAL;
 		goto out;
 	}
@@ -841,10 +887,31 @@ kwboot_img_patch_hdr(void *img, size_t size)
 		}
 	}
 
+	if (hdrsz > le32_to_cpu(hdr->srcaddr) ||
+	    *size < le32_to_cpu(hdr->srcaddr) + le32_to_cpu(hdr->blocksize)) {
+		errno = EINVAL;
+		goto out;
+	}
+
 	hdr->blockid = IBR_HDR_UART_ID;
 
+	if (hdrsz % KWBOOT_XM_BLKSZ) {
+		size_t offset = (KWBOOT_XM_BLKSZ - hdrsz % KWBOOT_XM_BLKSZ) %
+				KWBOOT_XM_BLKSZ;
+
+		if (is_secure) {
+			fprintf(stderr, "Cannot align image with secure header\n");
+			errno = EINVAL;
+			goto out;
+		}
+
+		kwboot_printv("Aligning image header to Xmodem block size\n");
+		kwboot_img_grow_hdr(img, size, offset);
+	}
+
 	hdr->checksum = kwboot_hdr_csum8(hdr) - csum;
 
+	*size = le32_to_cpu(hdr->srcaddr) + le32_to_cpu(hdr->blocksize);
 	rc = 0;
 out:
 	return rc;
@@ -971,13 +1038,13 @@ main(int argc, char **argv)
 	}
 
 	if (imgpath) {
-		img = kwboot_mmap_image(imgpath, &size);
+		img = kwboot_read_image(imgpath, &size, KWBOOT_XM_BLKSZ);
 		if (!img) {
 			perror(imgpath);
 			goto out;
 		}
 
-		rc = kwboot_img_patch_hdr(img, size);
+		rc = kwboot_img_patch_hdr(img, &size);
 		if (rc) {
 			fprintf(stderr, "%s: Invalid image.\n", imgpath);
 			goto out;
@@ -1020,7 +1087,7 @@ out:
 		close(tty);
 
 	if (img)
-		munmap(img, size);
+		free(img);
 
 	return rv;
 
-- 
2.31.1