[ Upstream commit 0e31e3573f ]
When building ARCH=um with CONFIG_UML_X86=y and CONFIG_64BIT=y we get
the build errors:
drivers/misc/lkdtm/bugs.c: In function ‘lkdtm_UNSET_SMEP’:
drivers/misc/lkdtm/bugs.c:288:8: error: implicit declaration of function ‘native_read_cr4’ [-Werror=implicit-function-declaration]
cr4 = native_read_cr4();
^~~~~~~~~~~~~~~
drivers/misc/lkdtm/bugs.c:290:13: error: ‘X86_CR4_SMEP’ undeclared (first use in this function); did you mean ‘X86_FEATURE_SMEP’?
if ((cr4 & X86_CR4_SMEP) != X86_CR4_SMEP) {
^~~~~~~~~~~~
X86_FEATURE_SMEP
drivers/misc/lkdtm/bugs.c:290:13: note: each undeclared identifier is reported only once for each function it appears in
drivers/misc/lkdtm/bugs.c:297:2: error: implicit declaration of function ‘native_write_cr4’; did you mean ‘direct_write_cr4’? [-Werror=implicit-function-declaration]
native_write_cr4(cr4);
^~~~~~~~~~~~~~~~
direct_write_cr4
So specify that this block of code should only build when
CONFIG_X86_64=y *AND* CONFIG_UML is unset.
Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Acked-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20191213003522.66450-1-brendanhiggins@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
9e62f296db