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[v3,0/3] Add a new command in kgdb for vmcoreinfo

Message ID 20250113172936.1434532-1-tjarlama@gmail.com
Headers show
Series Add a new command in kgdb for vmcoreinfo | expand

Message

Amal Raj T Jan. 13, 2025, 5:29 p.m. UTC 
From: Amal Raj T <amalrajt@meta.com>

This patch set introduces a new custom query packet,
`qlinux.vmcoreinfo`, to kgdb. This packet retrieves kernel's
vmcoreinfo text, which contains crucial debugging information
such as the KASLR offset, kernel release, `phys_base` etc.

This implementation includes a new binary-encoder (`mem2ebin`)
instead of the existing hex-encoder (`mem2hex`) to reduce the
amount of data sent over the wire.

These changes also move the LF -> CRLF replacement logic from
serial drivers to KDB, since KDB is the only user of this
logic, and the existing replacement results in incorrect
checksums generated by KGDB.

Link:
- https://github.com/osandov/drgn/wiki/GDB-Remote-Protocol-proposal:-linux.vmcoreinfo-query-packet

v3:
- Added relevant links for the new query
- Updated `tmp+=1` to `tmp++`
- Added few examples and additional documentation for encoding function
Amal Raj T (3):
  kgdb: Add kgdb_mem2ebin function for converting memory to binary
    format
  serial: Move LF -> CRLF replacement from serial console to kdb
  kgdb: Add command linux.vmcoreinfo to kgdb

 drivers/tty/serial/serial_core.c |   2 -
 include/linux/kgdb.h             |   1 +
 kernel/debug/gdbstub.c           | 131 ++++++++++++++++++++-----------
 kernel/debug/kdb/kdb_io.c        |   2 +
 lib/Kconfig.kgdb                 |   1 +
 5 files changed, 91 insertions(+), 46 deletions(-)