@@ -379,16 +379,18 @@ static const char *open_pack_file(const char *pack_name)
static void parse_pack_header(void)
{
- struct pack_header *hdr = fill(sizeof(struct pack_header));
+ unsigned char *hdr = fill(sizeof(struct pack_header));
/* Header consistency check */
- if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
+ if (get_be32(hdr) != PACK_SIGNATURE)
die(_("pack signature mismatch"));
- if (!pack_version_ok(hdr->hdr_version))
+ hdr += 4;
+ if (!pack_version_ok_native(get_be32(hdr)))
die(_("pack version %"PRIu32" unsupported"),
- ntohl(hdr->hdr_version));
+ get_be32(hdr));
+ hdr += 4;
- nr_objects = ntohl(hdr->hdr_entries);
+ nr_objects = get_be32(hdr);
use(sizeof(struct pack_header));
}
@@ -579,15 +579,16 @@ static void unpack_one(unsigned nr)
static void unpack_all(void)
{
int i;
- struct pack_header *hdr = fill(sizeof(struct pack_header));
+ unsigned char *hdr = fill(sizeof(struct pack_header));
- nr_objects = ntohl(hdr->hdr_entries);
-
- if (ntohl(hdr->hdr_signature) != PACK_SIGNATURE)
+ if (get_be32(hdr) != PACK_SIGNATURE)
die("bad pack file");
- if (!pack_version_ok(hdr->hdr_version))
+ hdr += 4;
+ if (!pack_version_ok_native(get_be32(hdr)))
die("unknown pack file version %"PRIu32,
- ntohl(hdr->hdr_version));
+ get_be32(hdr));
+ hdr += 4;
+ nr_objects = get_be32(hdr);
use(sizeof(struct pack_header));
if (!quiet)
@@ -13,7 +13,8 @@ struct repository;
*/
#define PACK_SIGNATURE 0x5041434b /* "PACK" */
#define PACK_VERSION 2
-#define pack_version_ok(v) ((v) == htonl(2) || (v) == htonl(3))
+#define pack_version_ok(v) pack_version_ok_native(ntohl(v))
+#define pack_version_ok_native(v) ((v) == 2 || (v) == 3)
struct pack_header {
uint32_t hdr_signature;
uint32_t hdr_version;
Both of these commands read the incoming pack into a static unsigned char buffer in BSS, and then parse it by casting the start of the buffer to a struct pack_header. This can result in SIGBUS on some platforms if the compiler doesn't place the buffer in a position that is properly aligned for 4-byte integers. This reportedly happens with unpack-objects (but not index-pack) on sparc64 when compiled with clang (but not gcc). But we are definitely in the wrong in both spots; since the buffer's type is unsigned char, we can't depend on larger alignment. When it works it is only because we are lucky. We'll fix this by switching to get_be32() to read the headers (just like the last few commits similarly switched us to put_be32() for writing into the same buffer). It would be nice to factor this out into a common helper function, but the interface ends up quite awkward. Either the caller needs to hardcode how many bytes we'll need, or it needs to pass us its fill()/use() functions as pointers. So I've just fixed both spots in the same way; this is not code that is likely to be repeated a third time (most of the pack reading code uses an mmap'd buffer, which should be properly aligned). I did make one tweak to the shared code: our pack_version_ok() macro expects us to pass the big-endian value we'd get by casting. We can introduce a "native" variant which uses the host integer ordering. Reported-by: Koakuma <koachan@protonmail.com> Signed-off-by: Jeff King <peff@peff.net> --- New in v2. I did write the function-pointer version, and it's not even _too_ bad to read. But while trying to write a comment documenting the helper, it was just too gross to justify. builtin/index-pack.c | 12 +++++++----- builtin/unpack-objects.c | 13 +++++++------ pack.h | 3 ++- 3 files changed, 16 insertions(+), 12 deletions(-)