util/cbfstool: calculate cbfs file size for xip stages

The initial lookup for cbfs location for xip stages is implicitly
using the ELF size assuming it's relatively equivalent. However,
if the ELF that is being converted contains debug information or
other metadata then the location lookup can fail because the ELF is
considerably bigger than the real footprint.

BUG=b:70801221

Change-Id: I47024dcd8205a09885d3a3f76e255eb5e3c55d9e
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/22936
Reviewed-by: Furquan Shaikh <furquan@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

3 files changed, 52 insertions, 9 deletions

diff --git a/util/cbfstool/cbfstool.c b/util/cbfstool/cbfstool.c
index 77dbf72e97..1f71906ef6 100644
--- a/util/cbfstool/cbfstool.c
+++ b/util/cbfstool/cbfstool.c
@@ -27,6 +27,7 @@
 #include "cbfs.h"
 #include "cbfs_image.h"
 #include "cbfs_sections.h"
+#include "elfparsing.h"
 #include "fit.h"
 #include "partitioned_file.h"
 #include <commonlib/fsp.h>
@@ -147,7 +148,8 @@ static unsigned convert_to_from_top_aligned(const struct buffer *region,
 	return convert_to_from_absolute_top_aligned(region, offset);
 }
 
-static int do_cbfs_locate(int32_t *cbfs_addr, size_t metadata_size)
+static int do_cbfs_locate(int32_t *cbfs_addr, size_t metadata_size,
+			size_t data_size)
 {
 	if (!param.filename) {
 		ERROR("You need to specify -f/--filename.\n");
@@ -167,12 +169,18 @@ static int do_cbfs_locate(int32_t *cbfs_addr, size_t metadata_size)
 	if (cbfs_get_entry(&image, param.name))
 		WARN("'%s' already in CBFS.\n", param.name);
 
-	struct buffer buffer;
-	if (buffer_from_file(&buffer, param.filename) != 0) {
-		ERROR("Cannot load %s.\n", param.filename);
-		return 1;
+	if (!data_size) {
+		struct buffer buffer;
+		if (buffer_from_file(&buffer, param.filename) != 0) {
+			ERROR("Cannot load %s.\n", param.filename);
+			return 1;
+		}
+		data_size = buffer.size;
+		buffer_delete(&buffer);
 	}
 
+	DEBUG("File size is %zd (0x%zx)\n", data_size, data_size);
+
 	/* Include cbfs_file size along with space for with name. */
 	metadata_size += cbfs_calculate_file_header_size(param.name);
 	/* Adjust metadata_size if additional attributes were added */
@@ -187,9 +195,8 @@ static int do_cbfs_locate(int32_t *cbfs_addr, size_t metadata_size)
 	if (param.hash != VB2_HASH_INVALID)
 		metadata_size += sizeof(struct cbfs_file_attr_hash);
 
-	int32_t address = cbfs_locate_entry(&image, buffer.size, param.pagesize,
+	int32_t address = cbfs_locate_entry(&image, data_size, param.pagesize,
 						param.alignment, metadata_size);
-	buffer_delete(&buffer);
 
 	if (address == -1) {
 		ERROR("'%s' can't fit in CBFS for page-size %#x, align %#x.\n",
@@ -579,8 +586,15 @@ static int cbfstool_convert_mkstage(struct buffer *buffer, uint32_t *offset,
 
 	if (param.stage_xip) {
 		int32_t address;
+		size_t data_size;
+
+		if (elf_program_file_size(buffer, &data_size) < 0) {
+			ERROR("Could not obtain ELF size\n");
+			return 1;
+		}
 
-		if (do_cbfs_locate(&address, sizeof(struct cbfs_stage)))  {
+		if (do_cbfs_locate(&address, sizeof(struct cbfs_stage),
+			data_size))  {
 			ERROR("Could not find location for XIP stage.\n");
 			return 1;
 		}
@@ -684,7 +698,7 @@ static int cbfs_add(void)
 	if (param.alignment) {
 		/* CBFS compression file attribute is unconditionally added. */
 		size_t metadata_sz = sizeof(struct cbfs_file_attr_compression);
-		if (do_cbfs_locate(&address, metadata_sz))
+		if (do_cbfs_locate(&address, metadata_sz, 0))
 			return 1;
 		local_baseaddress = address;
 	}
diff --git a/util/cbfstool/elfheaders.c b/util/cbfstool/elfheaders.c
index acb25a7475..36226639d0 100644
--- a/util/cbfstool/elfheaders.c
+++ b/util/cbfstool/elfheaders.c
@@ -1440,3 +1440,26 @@ int elf_writer_add_rel(struct elf_writer *ew, const char *sym, Elf64_Addr addr)
 
 	return add_rel(rel_sec, &rel);
 }
+
+int elf_program_file_size(const struct buffer *input, size_t *file_size)
+{
+	Elf64_Ehdr ehdr;
+	Elf64_Phdr *phdr;
+	int i;
+	size_t loadable_file_size = 0;
+
+	if (elf_headers(input, &ehdr, &phdr, NULL))
+		return -1;
+
+	for (i = 0; i < ehdr.e_phnum; i++) {
+		if (phdr[i].p_type != PT_LOAD)
+			continue;
+		loadable_file_size += phdr[i].p_filesz;
+	}
+
+	*file_size = loadable_file_size;
+
+	free(phdr);
+
+	return 0;
+}
diff --git a/util/cbfstool/elfparsing.h b/util/cbfstool/elfparsing.h
index 978592bc46..1c6bf5e81a 100644
--- a/util/cbfstool/elfparsing.h
+++ b/util/cbfstool/elfparsing.h
@@ -124,4 +124,10 @@ int elf_writer_add_rel(struct elf_writer *ew, const char *sym, Elf64_Addr addr);
  */
 int elf_writer_serialize(struct elf_writer *ew, struct buffer *out);
 
+/*
+ * Calculate the loadable program's file size footprint. Returns < 0 on error,
+ * 0 on success.
+ */
+int elf_program_file_size(const struct buffer *input, size_t *file_size);
+
 #endif /* ELFPARSING_H */