[lkml]   [2019]   [Dec]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Patch in this message
Subject[PATCH v1] lkdtm/bugs: fix build error in lkdtm_UNSET_SMEP
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) {
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]

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 <>

This patch is part of my larger effort to get allyesconfig closer to
working for ARCH=um. For more information about that, checkout the cover
letter for a related patchset here:

drivers/misc/lkdtm/bugs.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/misc/lkdtm/bugs.c b/drivers/misc/lkdtm/bugs.c
index a4fdad04809a9..6c1aab177fced 100644
--- a/drivers/misc/lkdtm/bugs.c
+++ b/drivers/misc/lkdtm/bugs.c
@@ -278,7 +278,7 @@ void lkdtm_STACK_GUARD_PAGE_TRAILING(void)

void lkdtm_UNSET_SMEP(void)
-#ifdef CONFIG_X86_64
#define MOV_CR4_DEPTH 64
void (*direct_write_cr4)(unsigned long val);
unsigned char *insn;
 \ /
  Last update: 2019-12-13 01:36    [W:0.060 / U:0.544 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site