Change in flashrom[master]: libflashrom/fmap: Don't use off_t for flash offsets

[Edward O'Callaghan (Code Review)]

Edward O'Callaghan has submitted this change. ( https://review.coreboot.org/c/flashrom/+/61943 )

Change subject: libflashrom/fmap: Don't use off_t for flash offsets
......................................................................

libflashrom/fmap: Don't use off_t for flash offsets

off_t is a special POSIX type that is used to represent file offsets in
certain APIs (e.g. lseek(), mmap()), and should not be reused to
represent anything else (such as flash offsets). In particular, the
width of the type may change based on the definition of the
_FILE_OFFSET_BITS macro. Using such a type at the libflashrom interface
is particularly dangerous, because if a program is built with a
different _FILE_OFFSET_BITS value than libflashrom, the resulting ABI
corruption will cause very very nasty and confusing bugs. This patch
replaces all instances of off_t that are not related to file offsets
with (s)size_t.

BUG=b:219811851
TEST=`elogtool list` on cherry.

Signed-off-by: Julius Werner 
Change-Id: I68a386973f79ea634f63dfcd7d95a63400e1fdee
Reviewed-on: https://review.coreboot.org/c/flashrom/+/61943
Reviewed-by: Nico Huber 
Reviewed-by: Angel Pons 
Reviewed-by: Edward O'Callaghan 
Reviewed-by: Nikolai Artemiev 
Tested-by: build bot (Jenkins) 
---
M fmap.c
M libflashrom.c
M libflashrom.h
3 files changed, 6 insertions(+), 6 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Nico Huber: Looks good to me, but someone else must approve
  Angel Pons: Looks good to me, but someone else must approve
  Edward O'Callaghan: Looks good to me, approved
  Nikolai Artemiev: Looks good to me, but someone else must approve

diff --git a/fmap.c b/fmap.c
index 0236b62..bd847bd 100644
--- a/fmap.c
+++ b/fmap.c
@@ -91,15 +91,15 @@
  *         -1 to indicate that fmap was not found
  *         -2 to indicate fmap is truncated or exceeds buffer + len
  */
-static off_t fmap_lsearch(const uint8_t *buf, size_t len)
+static ssize_t fmap_lsearch(const uint8_t *buf, size_t len)
 {
-	off_t offset;
+	ssize_t offset;
    bool fmap_found = 0;

if (len < sizeof(struct fmap))
    	return -1;

-	for (offset = 0; offset <= (off_t)(len - sizeof(struct fmap)); offset++) {
+	for (offset = 0; offset <= (ssize_t)(len - sizeof(struct fmap)); offset++) {
    	if (is_valid_fmap((struct fmap *)&buf[offset])) {
    		fmap_found = 1;
    		break;
@@ -131,7 +131,7 @@
  */
 int fmap_read_from_buffer(struct fmap **fmap_out, const uint8_t *const buf, size_t len)
 {
-	off_t offset = fmap_lsearch(buf, len);
+	ssize_t offset = fmap_lsearch(buf, len);
    if (offset < 0) {
    	msg_gdbg("Unable to find fmap in provided buffer.\n");
    	return 2;
diff --git a/libflashrom.c b/libflashrom.c
index fb70934..d66c295 100644
--- a/libflashrom.c
+++ b/libflashrom.c
@@ -534,7 +534,7 @@
  *         1 on any other error.
  */
 int flashrom_layout_read_fmap_from_rom(struct flashrom_layout **const layout,
-		struct flashctx *const flashctx, off_t offset, size_t len)
+		struct flashctx *const flashctx, size_t offset, size_t len)
 {
 #ifndef __FLASHROM_LITTLE_ENDIAN__
    return 3;
diff --git a/libflashrom.h b/libflashrom.h
index 557978d..1c9498e 100644
--- a/libflashrom.h
+++ b/libflashrom.h
@@ -109,7 +109,7 @@
 int flashrom_layout_new(struct flashrom_layout **);
 int flashrom_layout_read_from_ifd(struct flashrom_layout **, struct flashrom_flashctx *, const void *dump, size_t len);
 int flashrom_layout_read_fmap_from_rom(struct flashrom_layout **,
-		struct flashrom_flashctx *, off_t offset, size_t length);
+		struct flashrom_flashctx *, size_t offset, size_t length);
 int flashrom_layout_read_fmap_from_buffer(struct flashrom_layout **layout,
    	struct flashrom_flashctx *, const uint8_t *buf, size_t len);
 int flashrom_layout_add_region(struct flashrom_layout *, size_t start, size_t end, const char *name);

2 is the latest approved patch-set.
No files were changed between the latest approved patch-set and the submitted one.