Skip to content
Commit b8d3f244 authored by Petr Vandrovec's avatar Petr Vandrovec Committed by Linus Torvalds
Browse files

Do not replace whole memcpy in apply alternatives



apply_alternatives uses memcpy() to apply alternatives.  Which has the
unfortunate effect that while applying memcpy alternative to memcpy
itself it tries to overwrite itself with nops - which causes #UD fault
as it overwrites half of an instruction in copy loop, and from this
point on only possible outcome is triplefault and reboot.

So let's overwrite only first two instructions of memcpy - as long as
the main memcpy loop is not in first two bytes it will work fine.

Signed-off-by: default avatarPetr Vandrovec <petr@vandrovec.name>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 3864e8cc
Loading
Loading
Loading
Loading
0% Loading or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment