From 04ced0296e66ff0fbeafbbf2e94d2441237f49c8 Mon Sep 17 00:00:00 2001
From: Pali Rohár
Date: Fri, 24 Sep 2021 23:07:03 +0200
Subject: tools: kwboot: Round up header size to 128 B when patching

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>
Reviewed-by: Stefan Roese <sr@denx.de>
---
 tools/kwboot.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 77 insertions(+), 12 deletions(-)

(limited to 'tools')

diff --git a/tools/kwboot.c b/tools/kwboot.c
index e60f7c5b7ae..4fae44c46e9 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>
 
 /*
@@ -706,11 +705,12 @@ 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;
@@ -723,17 +723,30 @@ 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)
@@ -769,8 +782,39 @@ 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(img);
+	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) {
+		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;
@@ -783,7 +827,7 @@ kwboot_img_patch_hdr(void *img, size_t size)
 	rc = -1;
 	hdr = img;
 
-	if (size < hdrsz) {
+	if (*size < hdrsz) {
 		errno = EINVAL;
 		goto out;
 	}
@@ -797,7 +841,7 @@ kwboot_img_patch_hdr(void *img, size_t size)
 
 	hdrsz = kwbheader_size(hdr);
 
-	if (size < hdrsz) {
+	if (*size < hdrsz) {
 		errno = EINVAL;
 		goto out;
 	}
@@ -844,6 +888,12 @@ kwboot_img_patch_hdr(void *img, size_t size)
 		break;
 	}
 
+	if (hdrsz > le32_to_cpu(hdr->srcaddr) ||
+	    *size < le32_to_cpu(hdr->srcaddr) + le32_to_cpu(hdr->blocksize)) {
+		errno = EINVAL;
+		goto out;
+	}
+
 	is_secure = kwboot_img_is_secure(img);
 
 	if (hdr->blockid != IBR_HDR_UART_ID) {
@@ -858,8 +908,23 @@ kwboot_img_patch_hdr(void *img, size_t size)
 		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;
@@ -986,13 +1051,13 @@ 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;
@@ -1035,7 +1100,7 @@ out:
 		close(tty);
 
 	if (img)
-		munmap(img, size);
+		free(img);
 
 	return rv;
 
-- 
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