From: Simon Glass <sjg@chromium.org>
Date: Wed, 27 Dec 2023 21:07:05 +0000 (-0800)
Subject: bloblist: Checksum the entire bloblist
X-Git-Url: http://git.dujemihanovic.xyz/?a=commitdiff_plain;h=997dac6edebe5b82f4d6f9b90753f0af6e9d04f0;p=u-boot.git

bloblist: Checksum the entire bloblist

Use a sinple 8-bit checksum for bloblist, as specified by the spec
version 0.9.
Spec v0.9 specifies that the entire bloblist area is checksummed,
including unused portions. Update the code to follow this.

Signed-off-by: Simon Glass <sjg@chromium.org>
Co-developed-by: Raymond Mao <raymond.mao@linaro.org>
Signed-off-by: Raymond Mao <raymond.mao@linaro.org>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
---

diff --git a/common/bloblist.c b/common/bloblist.c
index 88e2a0f5c0..705d9c6ae9 100644
--- a/common/bloblist.c
+++ b/common/bloblist.c
@@ -13,6 +13,7 @@
 #include <malloc.h>
 #include <mapmem.h>
 #include <spl.h>
+#include <tables_csum.h>
 #include <asm/global_data.h>
 #include <u-boot/crc.h>
 
@@ -318,16 +319,10 @@ int bloblist_resize(uint tag, int new_size)
 
 static u32 bloblist_calc_chksum(struct bloblist_hdr *hdr)
 {
-	struct bloblist_rec *rec;
-	u32 chksum;
+	u8 chksum;
 
-	chksum = crc32(0, (unsigned char *)hdr,
-		       offsetof(struct bloblist_hdr, chksum));
-	foreach_rec(rec, hdr) {
-		chksum = crc32(chksum, (void *)rec, rec_hdr_size(rec));
-		chksum = crc32(chksum, (void *)rec + rec_hdr_size(rec),
-			       rec->size);
-	}
+	chksum = table_compute_checksum(hdr, hdr->alloced);
+	chksum += hdr->chksum;
 
 	return chksum;
 }
diff --git a/include/bloblist.h b/include/bloblist.h
index 68f97395b7..d2dcad69a1 100644
--- a/include/bloblist.h
+++ b/include/bloblist.h
@@ -174,11 +174,10 @@ enum bloblist_tag_t {
  *	sizeof(bloblist_hdr) since we need at least that much space to store a
  *	valid bloblist
  * @spare: Spare space (for future use)
- * @chksum: CRC32 for the entire bloblist allocated area. Since any of the
+ * @chksum: checksum for the entire bloblist allocated area. Since any of the
  *	blobs can be altered after being created, this checksum is only valid
  *	when the bloblist is finalised before jumping to the next stage of boot.
- *	Note that chksum is last to make it easier to exclude it from the
- *	checksum calculation.
+ *	This is the value needed to make all checksummed bytes sum to 0
  */
 struct bloblist_hdr {
 	u32 magic;
diff --git a/test/bloblist.c b/test/bloblist.c
index 8b435e27ca..49ac4b92ae 100644
--- a/test/bloblist.c
+++ b/test/bloblist.c
@@ -237,12 +237,18 @@ static int bloblist_test_checksum(struct unit_test_state *uts)
 	*data2 -= 1;
 
 	/*
-	 * Changing data outside the range of valid data should not affect
-	 * the checksum.
+	 * Changing data outside the range of valid data should affect the
+	 * checksum.
 	 */
 	ut_assertok(bloblist_check(TEST_ADDR, TEST_BLOBLIST_SIZE));
 	data[TEST_SIZE]++;
+	ut_asserteq(-EIO, bloblist_check(TEST_ADDR, TEST_BLOBLIST_SIZE));
+	data[TEST_SIZE]--;
+	ut_assertok(bloblist_check(TEST_ADDR, TEST_BLOBLIST_SIZE));
+
 	data2[TEST_SIZE2]++;
+	ut_asserteq(-EIO, bloblist_check(TEST_ADDR, TEST_BLOBLIST_SIZE));
+	data[TEST_SIZE]--;
 	ut_assertok(bloblist_check(TEST_ADDR, TEST_BLOBLIST_SIZE));
 
 	return 0;