tree 967bd9f4d4d7fa2c57a8f194e05f47523f32c589
parent 9249f4bc4148caef423a9cd0139d9e917fb36341
author Tao Bao <tbao@google.com> 1524521740 -0700
committer Tao Bao <tbao@google.com> 1524677362 -0700

libsparse: Use 'size_t' for the 'len' parameter in callbacks.

This CL updates the callback function signature in
sparse_file_callback() and sparse_file_foreach_chunk().

Before:
int sparse_file_callback(
    struct sparse_file *s, bool sparse, bool crc,
    int (*write)(void *priv, const void *data, int len), void *priv);

int sparse_file_foreach_chunk(
    struct sparse_file *s, bool sparse, bool crc,
    int (*write)(
        void *priv, const void *data, int len, unsigned int block,
        unsigned int nr_blocks),
    void *priv);

After:
int sparse_file_callback(
    struct sparse_file *s, bool sparse, bool crc,
    int (*write)(void *priv, const void *data, size_t len), void *priv);

int sparse_file_foreach_chunk(
    struct sparse_file *s, bool sparse, bool crc,
    int (*write)(
        void *priv, const void *data, size_t len, unsigned int block,
        unsigned int nr_blocks),
    void *priv);

The length (i.e. 'len') comes from the size of a chunk, which could be
legitimately larger than INT_MAX. Prior to this CL, callers (e.g.
write_sparse_data_chunk()) were already passing unsigned int to the
callbacks. When a chunk size exceeds INT_MAX, the callback would see a
negative value, which could lead to undesired behavior. For example,
out_counter_write(), as one of the internal callbacks in libsparse,
gives a wrong sum of chunk sizes, which in turn fails the fastboot
flashing when given a huge sparse image.

It also defines SPARSE_CALLBACK_USES_SIZE_T that allows clients to keep
their codes compatibile with both versions.

Bug: 78432315
Test: `m dist` (with matching changes to all the clients)
Test: Build fastboot and successfully flash a previously failing (huge)
      sparse image.
Change-Id: Iac4bcf7b57039d08af3c57f4be00d75f6b693d93