Hi,
On Mon, Apr 22, 2024 at 05:35:53PM +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!
Signed-off-by: Daniel Thompson daniel.thompson@linaro.org
Seems to work nicely.
There is some weird behavior which was present before your patch and is still present with it (let >< represent cursor position):
[0]kdb> test_ap>< (now press TAB)
[0]kdb> test_aperfmperf>< (so far so good, we got our autocomplete)
[0]kdb> test_ap><erfmperf (now, let's move the cursor back and press TAB again)
[0]kdb> test_aperfmperf><erfmperf
This is because the autocomplete engine is not considering the characters after the cursor position. To be clear, this isn't really a bug but rather a decision to be made about which functionality is desired.
For example, my shell (zsh) will just simply move the cursor back to the end of the complete match instead of re-writing stuff.
At any rate, Tested-by: Justin Stitt justinstitt@google.com
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@lina...
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 | 133 ++++++++++++++++++++-------------------------- 1 file changed, 58 insertions(+), 75 deletions(-)
base-commit: dccce9b8780618986962ba37c373668bcf426866 change-id: 20240415-kgdb_read_refactor-2ea2dfc15dbb
Best regards,
Daniel Thompson daniel.thompson@linaro.org
Thanks Justin