diff options
| author | Eric Sandeen <sandeen@redhat.com> | 2015-10-12 07:04:15 +0200 |
|---|---|---|
| committer | Dave Chinner <david@fromorbit.com> | 2015-10-12 07:04:15 +0200 |
| commit | 91f9f5fe1e7350e872b3fbc3194e8183bddce514 (patch) | |
| tree | 5aa10aef830c70180c090d43d4cf905baf5d2f54 | |
| parent | xfs: pass total block res. as total xfs_bmapi_write() parameter (diff) | |
| download | linux-91f9f5fe1e7350e872b3fbc3194e8183bddce514.tar.xz linux-91f9f5fe1e7350e872b3fbc3194e8183bddce514.zip | |
xfs: avoid null *src in memcpy call in xlog_write
The gcc undefined behavior sanitizer caught this; surely
any sane memcpy implementation will no-op if size == 0,
but behavior with a *src of NULL is technically undefined
(declared nonnull), so avoid it here.
We are actually in this situation frequently via
xlog_commit_record(), because:
struct xfs_log_iovec reg = {
.i_addr = NULL,
.i_len = 0,
.i_type = XLOG_REG_TYPE_COMMIT,
};
Reported-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
| -rw-r--r-- | fs/xfs/xfs_log.c | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index 0c8ef767c3a9..af08326b0e41 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -2422,11 +2422,20 @@ xlog_write( &partial_copy_len); xlog_verify_dest_ptr(log, ptr); - /* copy region */ + /* + * Copy region. + * + * Unmount records just log an opheader, so can have + * empty payloads with no data region to copy. Hence we + * only copy the payload if the vector says it has data + * to copy. + */ ASSERT(copy_len >= 0); - memcpy(ptr, reg->i_addr + copy_off, copy_len); - xlog_write_adv_cnt(&ptr, &len, &log_offset, copy_len); - + if (copy_len > 0) { + memcpy(ptr, reg->i_addr + copy_off, copy_len); + xlog_write_adv_cnt(&ptr, &len, &log_offset, + copy_len); + } copy_len += start_rec_copy + sizeof(xlog_op_header_t); record_cnt++; data_cnt += contwr ? copy_len : 0; |