kasan: Add documentation for CONFIG_KASAN_EXTRA_INFO

This patch adds CONFIG_KASAN_EXTRA_INFO introduction information to
KASAN documentation.

Signed-off-by: Juntong Deng <juntong.deng@outlook.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Link: https://lore.kernel.org/r/AM6PR03MB5848C52B871DA67455F0B2F2994D2@AM6PR03MB5848.eurprd03.prod.outlook.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This commit is contained in:
Juntong Deng 2024-02-15 19:17:23 +00:00 committed by Jonathan Corbet
parent d4f42b71e8
commit eefe68280c

View File

@ -277,6 +277,27 @@ traces point to places in code that interacted with the object but that are not
directly present in the bad access stack trace. Currently, this includes
call_rcu() and workqueue queuing.
CONFIG_KASAN_EXTRA_INFO
~~~~~~~~~~~~~~~~~~~~~~~
Enabling CONFIG_KASAN_EXTRA_INFO allows KASAN to record and report more
information. The extra information currently supported is the CPU number and
timestamp at allocation and free. More information can help find the cause of
the bug and correlate the error with other system events, at the cost of using
extra memory to record more information (more cost details in the help text of
CONFIG_KASAN_EXTRA_INFO).
Here is the report with CONFIG_KASAN_EXTRA_INFO enabled (only the
different parts are shown)::
==================================================================
...
Allocated by task 134 on cpu 5 at 229.133855s:
...
Freed by task 136 on cpu 3 at 230.199335s:
...
==================================================================
Implementation details
----------------------