On Mon, Oct 1, 2018 at 3:46 PM Ben Peart <peartben@xxxxxxxxx> wrote:
> @@ -2479,6 +2491,7 @@ static int do_write_index(struct index_state *istate, struct tempfile *tempfile,
> if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0)
> return -1;
>
> + offset = lseek(newfd, 0, SEEK_CUR) + write_buffer_len;
Note, lseek() could in theory return -1 on error. Looking at the error
code list in the man page it's pretty unlikely though, unless
> +static size_t read_eoie_extension(const char *mmap, size_t mmap_size)
> +{
> + /*
> + * The end of index entries (EOIE) extension is guaranteed to be last
> + * so that it can be found by scanning backwards from the EOF.
> + *
> + * "EOIE"
> + * <4-byte length>
> + * <4-byte offset>
> + * <20-byte hash>
> + */
> + const char *index, *eoie;
> + uint32_t extsize;
> + size_t offset, src_offset;
> + unsigned char hash[GIT_MAX_RAWSZ];
> + git_hash_ctx c;
> +
> + /* ensure we have an index big enough to contain an EOIE extension */
> + if (mmap_size < sizeof(struct cache_header) + EOIE_SIZE_WITH_HEADER + the_hash_algo->rawsz)
Using sizeof() for on-disk structures could be dangerous because you
don't know how much padding there could be (I'm not sure if it's
actually specified in the C language spec). I've checked, on at least
x86 and amd64, sizeof(struct cache_header) is 12 bytes, but I don't
know if there are any crazy architectures out there that set higher
padding.
--
Duy
