25 Apr, 2019
3 commits
-
CONFIG_INIT_STACK_ALL turns on stack initialization based on
-ftrivial-auto-var-init in Clang builds, which has greater coverage
than CONFIG_GCC_PLUGINS_STRUCTLEAK_BYREF_ALL.-ftrivial-auto-var-init Clang option provides trivial initializers for
uninitialized local variables, variable fields and padding.It has three possible values:
pattern - uninitialized locals are filled with a fixed pattern
(mostly 0xAA on 64-bit platforms, see https://reviews.llvm.org/D54604
for more details, but 0x000000AA for 32-bit pointers) likely to cause
crashes when uninitialized value is used;
zero (it's still debated whether this flag makes it to the official
Clang release) - uninitialized locals are filled with zeroes;
uninitialized (default) - uninitialized locals are left intact.This patch uses only the "pattern" mode when CONFIG_INIT_STACK_ALL is
enabled.Developers have the possibility to opt-out of this feature on a
per-variable basis by using __attribute__((uninitialized)), but such
use should be well justified in comments.Co-developed-by: Alexander Potapenko
Signed-off-by: Alexander Potapenko
Signed-off-by: Kees Cook
Tested-by: Alexander Potapenko
Acked-by: Masahiro Yamada -
This moves the stackleak plugin options to Kconfig.hardening's memory
initialization menu.Signed-off-by: Kees Cook
Reviewed-by: Alexander Popov
Acked-by: Masahiro Yamada -
Right now kernel hardening options are scattered around various Kconfig
files. This can be a central place to collect these kinds of options
going forward. This is initially populated with the memory initialization
options from the gcc-plugins.Signed-off-by: Kees Cook
Acked-by: Masahiro Yamada
