On 201229 1240, Qiuhao Li wrote:
> If previous write commands write the same length of data with the same step,
> we view it as a hint.
>
> Signed-off-by: Qiuhao Li <qiuhao...@outlook.com>
Reviewed-by: Alexander Bulekov <alx...@bu.edu>
> ---
> scripts/oss-fuzz/minimize_qtest_trace.py | 56 ++++++++++++++++++++++++
> 1 file changed, 56 insertions(+)
>
> diff --git a/scripts/oss-fuzz/minimize_qtest_trace.py
> b/scripts/oss-fuzz/minimize_qtest_trace.py
> index a681984076..6cbf2b0419 100755
> --- a/scripts/oss-fuzz/minimize_qtest_trace.py
> +++ b/scripts/oss-fuzz/minimize_qtest_trace.py
> @@ -85,6 +85,43 @@ def check_if_trace_crashes(trace, path):
> return False
>
>
> +# If previous write commands write the same length of data at the same
> +# interval, we view it as a hint.
> +def split_write_hint(newtrace, i):
> + HINT_LEN = 3 # > 2
> + if i <=(HINT_LEN-1):
> + return None
> +
> + #find previous continuous write traces
> + k = 0
> + l = i-1
> + writes = []
> + while (k != HINT_LEN and l >= 0):
> + if newtrace[l].startswith("write "):
> + writes.append(newtrace[l])
> + k += 1
> + l -= 1
> + elif newtrace[l] == "":
> + l -= 1
> + else:
> + return None
> + if k != HINT_LEN:
> + return None
> +
> + length = int(writes[0].split()[2], 16)
> + for j in range(1, HINT_LEN):
> + if length != int(writes[j].split()[2], 16):
> + return None
> +
> + step = int(writes[0].split()[1], 16) - int(writes[1].split()[1], 16)
> + for j in range(1, HINT_LEN-1):
> + if step != int(writes[j].split()[1], 16) - \
> + int(writes[j+1].split()[1], 16):
> + return None
> +
> + return (int(writes[0].split()[1], 16)+step, length)
> +
> +
> def remove_minimizer(newtrace, outpath):
> remove_step = 1
> i = 0
> @@ -148,6 +185,25 @@ def remove_minimizer(newtrace, outpath):
> length = int(newtrace[i].split()[2], 16)
> data = newtrace[i].split()[3][2:]
> if length > 1:
> +
> + # Can we get a hint from previous writes?
> + hint = split_write_hint(newtrace, i)
> + if hint is not None:
> + hint_addr = hint[0]
> + hint_len = hint[1]
> + if hint_addr >= addr and hint_addr+hint_len <=
> addr+length:
> + newtrace[i] = "write {addr} {size}
> 0x{data}\n".format(
> + addr=hex(hint_addr),
> + size=hex(hint_len),
> + data=data[(hint_addr-addr)*2:\
> + (hint_addr-addr)*2+hint_len*2])
> + if check_if_trace_crashes(newtrace, outpath):
> + # next round
> + i += 1
> + continue
> + newtrace[i] = prior[0]
> +
> + # Try splitting it using a binary approach
> leftlength = int(length/2)
> rightlength = length - leftlength
> newtrace.insert(i+1, "")
> --
> 2.25.1
>
