"Derrick Stolee via GitGitGadget" <gitgitgadget@xxxxxxxxx> writes: > From: Derrick Stolee <dstolee@xxxxxxxxxxxxx> > > When calculating the sizes of certain chunks, we should use 64-bit > multiplication always. This allows us to properly predict the chunk > sizes without risk of overflow. > > Signed-off-by: Derrick Stolee <dstolee@xxxxxxxxxxxxx> > --- > midx.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) This one I find somewhat questionable for multiple reasons. * the fourth parameter of add_chunk() is of size_t, not uint64_t; shouldn't the multiplication be done in type size_t instead? * these mutiplications were introduced in "midx: use chunk-format API in write_midx_internal()"; that step should use the arithmetic with cast (if necessary) from the start, no? * There is "ctx.entries_nr * MIDX_CHUNKID_OFFSET_WIDTH" passed to add_chunk(), in the post-context of the first hunk. Shouldn't that be covered as well? I didn't grep for all uses of add_chunk(), but I wouldn't be surprised if this patch missed some of the calls that need the same treatment. > diff --git a/midx.c b/midx.c > index e94dcd34b7f..a365dac6bbc 100644 > --- a/midx.c > +++ b/midx.c > @@ -913,7 +913,7 @@ static int write_midx_internal(const char *object_dir, struct multi_pack_index * > add_chunk(cf, MIDX_CHUNKID_OIDFANOUT, > write_midx_oid_fanout, MIDX_CHUNK_FANOUT_SIZE); > add_chunk(cf, MIDX_CHUNKID_OIDLOOKUP, > - write_midx_oid_lookup, ctx.entries_nr * the_hash_algo->rawsz); > + write_midx_oid_lookup, (uint64_t)ctx.entries_nr * the_hash_algo->rawsz); > add_chunk(cf, MIDX_CHUNKID_OBJECTOFFSETS, > write_midx_object_offsets, > ctx.entries_nr * MIDX_CHUNK_OFFSET_WIDTH); > @@ -921,7 +921,7 @@ static int write_midx_internal(const char *object_dir, struct multi_pack_index * > if (ctx.large_offsets_needed) > add_chunk(cf, MIDX_CHUNKID_LARGEOFFSETS, > write_midx_large_offsets, > - ctx.num_large_offsets * MIDX_CHUNK_LARGE_OFFSET_WIDTH); > + (uint64_t)ctx.num_large_offsets * MIDX_CHUNK_LARGE_OFFSET_WIDTH); > > write_midx_header(f, get_num_chunks(cf), ctx.nr - dropped_packs); > write_chunkfile(cf, &ctx);
