Convert the verify_pack callback to struct object_id
Make the verify_pack_callback take a pointer to struct object_id. Change the pack checksum to use GIT_MAX_RAWSZ, even though it is not strictly an object ID. Doing so ensures resilience against future hash size changes, and allows us to remove hard-coded assumptions about how big the buffer needs to be. Also, use a union to convert the pointer from nth_packed_object_sha1 to to a pointer to struct object_id. This behavior is compatible with GCC and clang and explicitly sanctioned by C11. The alternatives are to just perform a cast, which would run afoul of strict aliasing rules, but should just work, and changing the pointer into an instance of struct object_id and copying the value. The latter operation could seriously bloat memory usage on fsck, which already uses a lot of memory on some repositories. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
brian m. carlson committed
May 6, 2017 at 22:10 UTC
9fd750461befcaf984d5966606308c8cd6912f3c
3 files changed
+18
-15
builtin/fsck.c
+3
-3
@@ -377,7 +377,7 @@ static int fsck_obj(struct object *obj)
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return 0;
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}
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-static int fsck_obj_buffer(const unsigned char *sha1, enum object_type type,
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+static int fsck_obj_buffer(const struct object_id *oid, enum object_type type,
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unsigned long size, void *buffer, int *eaten)
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{
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/*
@@ -385,10 +385,10 @@ static int fsck_obj_buffer(const unsigned char *sha1, enum object_type type,
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* verify_packfile(), data_valid variable for details.
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*/
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struct object *obj;
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- obj = parse_object_buffer(sha1, type, size, buffer, eaten);
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+ obj = parse_object_buffer(oid->hash, type, size, buffer, eaten);
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if (!obj) {
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errors_found |= ERROR_OBJECT;
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- return error("%s: object corrupt or missing", sha1_to_hex(sha1));
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+ return error("%s: object corrupt or missing", oid_to_hex(oid));
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}
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obj->flags = HAS_OBJ;
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return fsck_obj(obj);
pack-check.c
+14
-11
@@ -5,7 +5,10 @@
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struct idx_entry {
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off_t offset;
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- const unsigned char *sha1;
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+ union idx_entry_object {
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+ const unsigned char *hash;
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+ struct object_id *oid;
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+ } oid;
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unsigned int nr;
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};
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@@ -51,7 +54,7 @@ static int verify_packfile(struct packed_git *p,
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off_t index_size = p->index_size;
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const unsigned char *index_base = p->index_data;
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git_SHA_CTX ctx;
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- unsigned char sha1[20], *pack_sig;
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+ unsigned char hash[GIT_MAX_RAWSZ], *pack_sig;
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off_t offset = 0, pack_sig_ofs = 0;
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uint32_t nr_objects, i;
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int err = 0;
@@ -71,9 +74,9 @@ static int verify_packfile(struct packed_git *p,
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remaining -= (unsigned int)(offset - pack_sig_ofs);
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git_SHA1_Update(&ctx, in, remaining);
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} while (offset < pack_sig_ofs);
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- git_SHA1_Final(sha1, &ctx);
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+ git_SHA1_Final(hash, &ctx);
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pack_sig = use_pack(p, w_curs, pack_sig_ofs, NULL);
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- if (hashcmp(sha1, pack_sig))
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+ if (hashcmp(hash, pack_sig))
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err = error("%s SHA1 checksum mismatch",
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p->pack_name);
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if (hashcmp(index_base + index_size - 40, pack_sig))
@@ -90,8 +93,8 @@ static int verify_packfile(struct packed_git *p,
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entries[nr_objects].offset = pack_sig_ofs;
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/* first sort entries by pack offset, since unpacking them is more efficient that way */
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for (i = 0; i < nr_objects; i++) {
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- entries[i].sha1 = nth_packed_object_sha1(p, i);
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- if (!entries[i].sha1)
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+ entries[i].oid.hash = nth_packed_object_sha1(p, i);
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+ if (!entries[i].oid.hash)
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die("internal error pack-check nth-packed-object");
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entries[i].offset = nth_packed_object_offset(p, i);
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entries[i].nr = i;
@@ -112,7 +115,7 @@ static int verify_packfile(struct packed_git *p,
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if (check_pack_crc(p, w_curs, offset, len, nr))
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err = error("index CRC mismatch for object %s "
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"from %s at offset %"PRIuMAX"",
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- sha1_to_hex(entries[i].sha1),
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+ oid_to_hex(entries[i].oid.oid),
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p->pack_name, (uintmax_t)offset);
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}
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@@ -135,14 +138,14 @@ static int verify_packfile(struct packed_git *p,
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if (data_valid && !data)
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err = error("cannot unpack %s from %s at offset %"PRIuMAX"",
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- sha1_to_hex(entries[i].sha1), p->pack_name,
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+ oid_to_hex(entries[i].oid.oid), p->pack_name,
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(uintmax_t)entries[i].offset);
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- else if (check_sha1_signature(entries[i].sha1, data, size, typename(type)))
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+ else if (check_sha1_signature(entries[i].oid.hash, data, size, typename(type)))
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err = error("packed %s from %s is corrupt",
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- sha1_to_hex(entries[i].sha1), p->pack_name);
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+ oid_to_hex(entries[i].oid.oid), p->pack_name);
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else if (fn) {
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int eaten = 0;
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- err |= fn(entries[i].sha1, type, size, data, &eaten);
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+ err |= fn(entries[i].oid.oid, type, size, data, &eaten);
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if (eaten)
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data = NULL;
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}
pack.h
+1
-1
@@ -75,7 +75,7 @@ struct pack_idx_entry {
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struct progress;
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/* Note, the data argument could be NULL if object type is blob */
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-typedef int (*verify_fn)(const unsigned char*, enum object_type, unsigned long, void*, int*);
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+typedef int (*verify_fn)(const struct object_id *, enum object_type, unsigned long, void*, int*);
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extern const char *write_idx_file(const char *index_name, struct pack_idx_entry **objects, int nr_objects, const struct pack_idx_option *, const unsigned char *sha1);
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extern int check_pack_crc(struct packed_git *p, struct pack_window **w_curs, off_t offset, off_t len, unsigned int nr);