[PATCH 1/2] fip: Store image data in single buffer

[PATCH 1/2] fip: Store image data in single buffer

[Sascha Hauer]

Right now in fip_parse() we read the whole FIP image into an allocated
buffer, then allocate buffers for the different blobs contained in the
FIP image and memcpy the blobs there from the full buffer. Let's
optimize this a bit by keeping the full buffer. Instead of allocating
separate buffers for the blobs, just put pointers to the full buffers
into struct fip_image and set the buf_no_free flag indicating that they
should not be freed.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 lib/fip.c | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/lib/fip.c b/lib/fip.c
index 39b0fd20aa..806f172318 100644
--- a/lib/fip.c
+++ b/lib/fip.c
@@ -160,12 +160,15 @@ int fip_parse(struct fip_state *fip,
 {
 	struct stat st;
 	int fd;
-	char *buf, *bufend;
+	char *bufend;
 	fip_toc_header_t *toc_header;
 	fip_toc_entry_t *toc_entry;
 	int terminated = 0;
 	size_t st_size;
 
+	if (fip->buffer)
+		return -EBUSY;
+
 	fd = open(filename, O_RDONLY);
 	if (fd < 0) {
 		pr_err("open %s: %m\n", filename);
@@ -179,13 +182,13 @@ int fip_parse(struct fip_state *fip,
 
 	st_size = st.st_size;
 
-	buf = xmalloc(st_size);
-	if (read_full(fd, buf, st_size) != st_size) {
+	fip->buffer = xmalloc(st_size);
+	if (read_full(fd, fip->buffer, st_size) != st_size) {
 		pr_err("Failed to read %s: %m\n", filename);
 		return -errno;
 	}
 
-	bufend = buf + st_size;
+	bufend = fip->buffer + st_size;
 	close(fd);
 
 	if (st_size < sizeof(fip_toc_header_t)) {
@@ -193,7 +196,7 @@ int fip_parse(struct fip_state *fip,
 		return -ENODATA;
 	}
 
-	toc_header = (fip_toc_header_t *)buf;
+	toc_header = (fip_toc_header_t *)fip->buffer;
 	toc_entry = (fip_toc_entry_t *)(toc_header + 1);
 
 	if (toc_header->name != TOC_HEADER_NAME) {
@@ -223,7 +226,8 @@ int fip_parse(struct fip_state *fip,
 		 */
 		image = xzalloc(sizeof(*image));
 		image->toc_e = *toc_entry;
-		image->buffer = xmalloc(toc_entry->size);
+		image->buffer = fip->buffer + toc_entry->offset_address;
+		image->buf_no_free = true;
 		/* Overflow checks before memory copy. */
 		if (toc_entry->size > (uint64_t)-1 - toc_entry->offset_address) {
 			pr_err("FIP %s is corrupted: entry size exceeds 64 bit address space\n",
@@ -236,9 +240,6 @@ int fip_parse(struct fip_state *fip,
 			return -EINVAL;
 		}
 
-		memcpy(image->buffer, buf + toc_entry->offset_address,
-		    toc_entry->size);
-
 		/* If this is an unknown image, create a descriptor for it. */
 		desc = fip_lookup_image_desc_from_uuid(fip, &toc_entry->uuid);
 		if (desc == NULL) {
@@ -264,7 +265,7 @@ int fip_parse(struct fip_state *fip,
 		    filename);
 		return -EINVAL;
 	}
-	free(buf);
+
 	return 0;
 }
 
-- 
2.39.5

[PATCH 2/2] fip: add function to parse FIP from a buffer

[Sascha Hauer]

So far we can only parse a FIP image from a file. Provide fip_parse_buf()
to open a FIP image from a buffer.
The bulk of fip_parse() can be re-used for that. While at it use
read_file_2() to read in the FIP image.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 include/fiptool.h |  4 +++
 lib/fip.c         | 92 ++++++++++++++++++++++++++---------------------
 2 files changed, 56 insertions(+), 40 deletions(-)

diff --git a/include/fiptool.h b/include/fiptool.h
index bc42f7edd6..bb63a79c16 100644
--- a/include/fiptool.h
+++ b/include/fiptool.h
@@ -38,6 +38,7 @@ struct fip_state {
 	size_t nr_image_descs;
 	int verbose;
 	void *buffer;
+	bool buf_no_free;
 };
 
 #define pr_verbose(...) do { \
@@ -68,6 +69,9 @@ struct fip_image_desc *fip_lookup_image_desc_from_uuid(struct fip_state *fip,
 
 struct fip_image_desc *fip_lookup_image_desc_from_opt(struct fip_state *fip, char **arg);
 
+int fip_parse_buf(struct fip_state *fip, void *buf, size_t size,
+		  fip_toc_header_t *toc_header_out);
+
 int fip_parse(struct fip_state *fip,
 		     const char *filename, fip_toc_header_t *toc_header_out);
 
diff --git a/lib/fip.c b/lib/fip.c
index 806f172318..23e82098da 100644
--- a/lib/fip.c
+++ b/lib/fip.c
@@ -22,6 +22,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <libfile.h>
+#include <fs.h>
 
 #include <fip.h>
 #include <fiptool.h>
@@ -93,7 +94,9 @@ void fip_free(struct fip_state *fip)
 
 	ASSERT(fip->nr_image_descs == 0);
 
-	free(fip->buffer);
+	if (!fip->buf_no_free)
+		free(fip->buffer);
+
 	free(fip);
 }
 
@@ -155,44 +158,20 @@ struct fip_image_desc *fip_lookup_image_desc_from_opt(struct fip_state *fip, cha
 	return NULL;
 }
 
-int fip_parse(struct fip_state *fip,
-		     const char *filename, fip_toc_header_t *toc_header_out)
+static int fip_do_parse_buf(struct fip_state *fip, void *buf, size_t size,
+			    fip_toc_header_t *toc_header_out)
 {
-	struct stat st;
-	int fd;
 	char *bufend;
 	fip_toc_header_t *toc_header;
 	fip_toc_entry_t *toc_entry;
 	int terminated = 0;
-	size_t st_size;
-
-	if (fip->buffer)
-		return -EBUSY;
-
-	fd = open(filename, O_RDONLY);
-	if (fd < 0) {
-		pr_err("open %s: %m\n", filename);
-		return -errno;
-	}
-
-	if (fstat(fd, &st) == -1) {
-		pr_err("fstat %s: %m\n", filename);
-		return -errno;
-	}
-
-	st_size = st.st_size;
 
-	fip->buffer = xmalloc(st_size);
-	if (read_full(fd, fip->buffer, st_size) != st_size) {
-		pr_err("Failed to read %s: %m\n", filename);
-		return -errno;
-	}
+	fip->buffer = buf;
 
-	bufend = fip->buffer + st_size;
-	close(fd);
+	bufend = fip->buffer + size;
 
-	if (st_size < sizeof(fip_toc_header_t)) {
-		pr_err("FIP %s is truncated\n", filename);
+	if (size < sizeof(fip_toc_header_t)) {
+		pr_err("FIP is truncated\n");
 		return -ENODATA;
 	}
 
@@ -200,8 +179,8 @@ int fip_parse(struct fip_state *fip,
 	toc_entry = (fip_toc_entry_t *)(toc_header + 1);
 
 	if (toc_header->name != TOC_HEADER_NAME) {
-		pr_err("%s is not a FIP file: unknown magic = 0x%08x\n",
-		       filename, toc_header->name);
+		pr_err("not a FIP file: unknown magic = 0x%08x\n",
+		       toc_header->name);
 		return -EINVAL;
 	}
 
@@ -230,13 +209,12 @@ int fip_parse(struct fip_state *fip,
 		image->buf_no_free = true;
 		/* Overflow checks before memory copy. */
 		if (toc_entry->size > (uint64_t)-1 - toc_entry->offset_address) {
-			pr_err("FIP %s is corrupted: entry size exceeds 64 bit address space\n",
-			       filename);
+			pr_err("FIP is corrupted: entry size exceeds 64 bit address space\n");
 			return -EINVAL;
 		}
-		if (toc_entry->size + toc_entry->offset_address > st_size) {
-			pr_err("FIP %s is corrupted: entry size (0x%llx) exceeds FIP file size (0x%zx)\n",
-				filename, toc_entry->size + toc_entry->offset_address, st_size);
+		if (toc_entry->size + toc_entry->offset_address > size) {
+			pr_err("FIP is corrupted: entry size (0x%llx) exceeds FIP file size (0x%zx)\n",
+				toc_entry->size + toc_entry->offset_address, size);
 			return -EINVAL;
 		}
 
@@ -261,14 +239,48 @@ int fip_parse(struct fip_state *fip,
 	}
 
 	if (terminated == 0) {
-		pr_err("FIP %s does not have a ToC terminator entry\n",
-		    filename);
+		pr_err("FIP does not have a ToC terminator entry\n");
 		return -EINVAL;
 	}
 
 	return 0;
 }
 
+int fip_parse_buf(struct fip_state *fip, void *buf, size_t size,
+			    fip_toc_header_t *toc_header_out)
+{
+	if (fip->buffer)
+		return -EBUSY;
+
+	fip->buf_no_free = true;
+
+	return fip_do_parse_buf(fip, buf, size, toc_header_out);
+}
+
+int fip_parse(struct fip_state *fip,
+		     const char *filename, fip_toc_header_t *toc_header_out)
+{
+	size_t size;
+	int ret;
+	void *buf;
+
+	if (fip->buffer)
+		return -EBUSY;
+
+	ret = read_file_2(filename, &size, &buf, FILESIZE_MAX);
+	if (ret) {
+		pr_err("open %s: %m\n", filename);
+		return ret;
+	}
+
+	ret = fip_parse_buf(fip, buf, size, toc_header_out);
+
+	if (ret)
+		free(buf);
+
+	return ret;
+}
+
 static struct fip_image *fip_read_image_from_file(const uuid_t *uuid, const char *filename)
 {
 	struct stat st;
-- 
2.39.5