tree 44e3f94cbac26b7e9208a2b4b1cabb30c77acabc
parent d228bee8201a7ea77c414f1298b2f572f42c6113
author Daniel Thompson <daniel.thompson@linaro.org> 1581607000 +0000
committer Daniel Thompson <daniel.thompson@linaro.org> 1585756751 +0100

kdb: Censor attempts to set PROMPT without ENABLE_MEM_READ

Currently the PROMPT variable could be abused to provoke the printf()
machinery to read outside the current stack frame. Normally this
doesn't matter becaues md is already a much better tool for reading
from memory.

However the md command can be disabled by not setting KDB_ENABLE_MEM_READ.
Let's also prevent PROMPT from being modified in these circumstances.

Whilst adding a comment to help future code reviewers we also remove
the #ifdef where PROMPT in consumed. There is no problem passing an
unused (0) to snprintf when !CONFIG_SMP.
argument

Reported-by: Wang Xiayang <xywang.sjtu@sjtu.edu.cn>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>