Inspired by a patch from [Justin][1] I took a closer look at kdb_read().

Despite Justin's patch being a (correct) one-line manipulation it was a
tough patch to review because the surrounding code was hard to read and
it looked like there were unfixed problems.

This series isn't enough to make kdb_read() beautiful but it does make
it shorter, easier to reason about and fixes two buffer overflows and a
screen redraw problem!

[1]: https://lore.kernel.org/all/20240403-strncpy-kernel-debug-kdb-kdb_io-c-v1-1-7f78a08e9ff4@google.com/

Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
---
Changes in v3:
- Collected tags from v2
- Added comment to describe the hidden depths of kdb_position_cursor()
  (thanks Doug)
- Fixed a couple of typos in the patch descriptions (thanks Doug)
- Link to v2: https://lore.kernel.org/r/20240422-kgdb_read_refactor-v2-0-ed51f7d145fe@linaro.org

Changes in v2:
- No code changes!
- I belatedly realized that one of the cleanups actually fixed a buffer
  overflow so there are changes to Cc: (to add stable@...) and to one
  of the patch descriptions.
- Link to v1: https://lore.kernel.org/r/20240416-kgdb_read_refactor-v1-0-b18c2d01076d@linaro.org

---
Daniel Thompson (7):
      kdb: Fix buffer overflow during tab-complete
      kdb: Use format-strings rather than '\0' injection in kdb_read()
      kdb: Fix console handling when editing and tab-completing commands
      kdb: Merge identical case statements in kdb_read()
      kdb: Use format-specifiers rather than memset() for padding in kdb_read()
      kdb: Replace double memcpy() with memmove() in kdb_read()
      kdb: Simplify management of tmpbuffer in kdb_read()

 kernel/debug/kdb/kdb_io.c | 153 +++++++++++++++++++++++-----------------------
 1 file changed, 78 insertions(+), 75 deletions(-)
---
base-commit: dccce9b8780618986962ba37c373668bcf426866
change-id: 20240415-kgdb_read_refactor-2ea2dfc15dbb

Best regards,
-- 
Daniel Thompson <daniel.thompson@linaro.org>

On Wed, 24 Apr 2024 15:03:33 +0100, Daniel Thompson wrote:
> Inspired by a patch from [Justin][1] I took a closer look at kdb_read().
> 
> Despite Justin's patch being a (correct) one-line manipulation it was a
> tough patch to review because the surrounding code was hard to read and
> it looked like there were unfixed problems.
> 
> This series isn't enough to make kdb_read() beautiful but it does make
> it shorter, easier to reason about and fixes two buffer overflows and a
> screen redraw problem!
> 
> [...]

Applied, thanks!

[1/7] kdb: Fix buffer overflow during tab-complete
      commit: e9730744bf3af04cda23799029342aa3cddbc454
[2/7] kdb: Use format-strings rather than '\0' injection in kdb_read()
      commit: 09b35989421dfd5573f0b4683c7700a7483c71f9
[3/7] kdb: Fix console handling when editing and tab-completing commands
      commit: db2f9c7dc29114f531df4a425d0867d01e1f1e28
[4/7] kdb: Merge identical case statements in kdb_read()
      commit: 6244917f377bf64719551b58592a02a0336a7439
[5/7] kdb: Use format-specifiers rather than memset() for padding in kdb_read()
      commit: c9b51ddb66b1d96e4d364c088da0f1dfb004c574
[6/7] kdb: Replace double memcpy() with memmove() in kdb_read()
      commit: 80bd73c154e3063c4f9293163daf3262335f9f86
[7/7] kdb: Simplify management of tmpbuffer in kdb_read()
      commit: 64d504cfcd514743aaed3a5b79c060f0143149e9

Best regards,
-- 
Daniel Thompson <daniel.thompson@linaro.org>