Hi everyone, Amal is working on adding a custom query packet to kgdb for getting the kernel's vmcoreinfo. The rationale and details are available here: https://github.com/osandov/drgn/wiki/GDB-Remote-Protocol-proposal:-linux.vmcoreinfo-query-packet vmcoreinfo is about 3kB, so we were hoping to avoid hex-encoding the response and doubling the time it takes to transmit over a slow serial connection. Instead, we were hoping to use the escaped binary format, which escapes the characters #$}* and leaves other bytes untouched. We ran into a problem, though: vmcoreinfo contains newline characters, which the serial core replaces with CRLF; see commit c7d44a02ac60 ("serial_core: Commonalize crlf when working w/ a non open console port"). This effectively corrupts the data and causes a checksum mismatch. We'd love some input on how to work around this, especially from the kgdb maintainers. Here are a few options, in descending order of my preference: 1. Disable the LF -> CRLF replacement while sending binary data. 2. Escape the newlines using some other custom scheme. 3. Give up and hex-encode the response. Any thoughts? Thanks, Omar
