{
  "schemaVersion": 1,
  "evidenceType": "measured-linux-api-behavior",
  "generatedAt": "2026-10-17T00:35:37.308558+00:00",
  "environment": {
    "system": "Linux",
    "kernel": "6.8.0-146-generic",
    "machine": "x86_64",
    "compiler": "cc (Ubuntu 13.3.0-6ubuntu2~24.04.1) 13.3.0",
    "filesystem": "ext2/ext3",
    "compileFlags": [
      "-std=c11",
      "-O2",
      "-Wall",
      "-Wextra",
      "-Werror"
    ]
  },
  "sourceSha256": "2b162b1cf307292f75318b9baf231b7613e1565550759de41be65e8538bd4200",
  "runnerSha256": "ff9504e3ab45c777c681cbc470cc99b96ff82d5fd640e9eda9b49696907faac7",
  "repetitions": 5,
  "casesPerRepetition": 7,
  "allRepetitionsIdentical": true,
  "limitations": [
    "Single host and filesystem; deterministic examples, not a sampled population.",
    "Reads may use cache; no power loss, reboot, cache eviction or hardware verification.",
    "No concurrent writers, DAX, huge pages, partial-tail remapping or file-growth remapping.",
    "SIGBUS is induced only in a disposable child; files are temporary and immediately unlinked."
  ],
  "observations": [
    {
      "page_size_bytes": 4096,
      "private": {
        "mapped_byte": "P",
        "file_byte_after_sync": "A",
        "msync_return": 0
      },
      "shared": {
        "file_byte_before_sync": "S",
        "file_byte_after_sync": "S",
        "msync_return": 0
      },
      "closed_descriptor": {
        "mapped_byte": "A"
      },
      "oversize_mapping": {
        "mapping_bytes": 8192,
        "file_bytes": 4096
      },
      "partial_tail": {
        "initial_byte": 0,
        "stored_byte_before_sync": 84,
        "file_bytes_after_sync": 4095,
        "pread_at_eof_bytes": 0,
        "msync_return": 0
      },
      "unaligned_sync": {
        "address_offset_bytes": 1,
        "return_value": -1,
        "errno_name": "EINVAL"
      },
      "shrink": {
        "initial_bytes": 8192,
        "final_bytes": 4096,
        "access_offset_bytes": 4096,
        "child_signal": "SIGBUS"
      }
    },
    {
      "page_size_bytes": 4096,
      "private": {
        "mapped_byte": "P",
        "file_byte_after_sync": "A",
        "msync_return": 0
      },
      "shared": {
        "file_byte_before_sync": "S",
        "file_byte_after_sync": "S",
        "msync_return": 0
      },
      "closed_descriptor": {
        "mapped_byte": "A"
      },
      "oversize_mapping": {
        "mapping_bytes": 8192,
        "file_bytes": 4096
      },
      "partial_tail": {
        "initial_byte": 0,
        "stored_byte_before_sync": 84,
        "file_bytes_after_sync": 4095,
        "pread_at_eof_bytes": 0,
        "msync_return": 0
      },
      "unaligned_sync": {
        "address_offset_bytes": 1,
        "return_value": -1,
        "errno_name": "EINVAL"
      },
      "shrink": {
        "initial_bytes": 8192,
        "final_bytes": 4096,
        "access_offset_bytes": 4096,
        "child_signal": "SIGBUS"
      }
    },
    {
      "page_size_bytes": 4096,
      "private": {
        "mapped_byte": "P",
        "file_byte_after_sync": "A",
        "msync_return": 0
      },
      "shared": {
        "file_byte_before_sync": "S",
        "file_byte_after_sync": "S",
        "msync_return": 0
      },
      "closed_descriptor": {
        "mapped_byte": "A"
      },
      "oversize_mapping": {
        "mapping_bytes": 8192,
        "file_bytes": 4096
      },
      "partial_tail": {
        "initial_byte": 0,
        "stored_byte_before_sync": 84,
        "file_bytes_after_sync": 4095,
        "pread_at_eof_bytes": 0,
        "msync_return": 0
      },
      "unaligned_sync": {
        "address_offset_bytes": 1,
        "return_value": -1,
        "errno_name": "EINVAL"
      },
      "shrink": {
        "initial_bytes": 8192,
        "final_bytes": 4096,
        "access_offset_bytes": 4096,
        "child_signal": "SIGBUS"
      }
    },
    {
      "page_size_bytes": 4096,
      "private": {
        "mapped_byte": "P",
        "file_byte_after_sync": "A",
        "msync_return": 0
      },
      "shared": {
        "file_byte_before_sync": "S",
        "file_byte_after_sync": "S",
        "msync_return": 0
      },
      "closed_descriptor": {
        "mapped_byte": "A"
      },
      "oversize_mapping": {
        "mapping_bytes": 8192,
        "file_bytes": 4096
      },
      "partial_tail": {
        "initial_byte": 0,
        "stored_byte_before_sync": 84,
        "file_bytes_after_sync": 4095,
        "pread_at_eof_bytes": 0,
        "msync_return": 0
      },
      "unaligned_sync": {
        "address_offset_bytes": 1,
        "return_value": -1,
        "errno_name": "EINVAL"
      },
      "shrink": {
        "initial_bytes": 8192,
        "final_bytes": 4096,
        "access_offset_bytes": 4096,
        "child_signal": "SIGBUS"
      }
    },
    {
      "page_size_bytes": 4096,
      "private": {
        "mapped_byte": "P",
        "file_byte_after_sync": "A",
        "msync_return": 0
      },
      "shared": {
        "file_byte_before_sync": "S",
        "file_byte_after_sync": "S",
        "msync_return": 0
      },
      "closed_descriptor": {
        "mapped_byte": "A"
      },
      "oversize_mapping": {
        "mapping_bytes": 8192,
        "file_bytes": 4096
      },
      "partial_tail": {
        "initial_byte": 0,
        "stored_byte_before_sync": 84,
        "file_bytes_after_sync": 4095,
        "pread_at_eof_bytes": 0,
        "msync_return": 0
      },
      "unaligned_sync": {
        "address_offset_bytes": 1,
        "return_value": -1,
        "errno_name": "EINVAL"
      },
      "shrink": {
        "initial_bytes": 8192,
        "final_bytes": 4096,
        "access_offset_bytes": 4096,
        "child_signal": "SIGBUS"
      }
    }
  ]
}