From cea23efb4de2d31e72a576026b213e15d6792976 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Thu, 2 Jan 2020 12:29:17 -0800 Subject: lkdtm/bugs: Make double-fault test always available Adjust the DOUBLE_FAULT test to always be available (so test harnesses don't have to make exceptions more missing tests), and for the arch-specific tests to "XFAIL" so that test harnesses can reason about expected vs unexpected failures. Fixes: b09511c253e5 ("lkdtm: Add a DOUBLE_FAULT crash type on x86") Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/202001021226.751D3F869D@keescook Signed-off-by: Greg Kroah-Hartman --- drivers/misc/lkdtm/bugs.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'drivers/misc') diff --git a/drivers/misc/lkdtm/bugs.c b/drivers/misc/lkdtm/bugs.c index a4fdad04809a..9eda771d3a37 100644 --- a/drivers/misc/lkdtm/bugs.c +++ b/drivers/misc/lkdtm/bugs.c @@ -338,13 +338,13 @@ void lkdtm_UNSET_SMEP(void) native_write_cr4(cr4); } #else - pr_err("FAIL: this test is x86_64-only\n"); + pr_err("XFAIL: this test is x86_64-only\n"); #endif } -#ifdef CONFIG_X86_32 void lkdtm_DOUBLE_FAULT(void) { +#ifdef CONFIG_X86_32 /* * Trigger #DF by setting the stack limit to zero. This clobbers * a GDT TLS slot, which is okay because the current task will die @@ -373,6 +373,8 @@ void lkdtm_DOUBLE_FAULT(void) asm volatile ("movw %0, %%ss; addl $0, (%%esp)" :: "r" ((unsigned short)(GDT_ENTRY_TLS_MIN << 3))); - panic("tried to double fault but didn't die\n"); -} + pr_err("FAIL: tried to double fault but didn't die\n"); +#else + pr_err("XFAIL: this test is ia32-only\n"); #endif +} -- cgit v1.2.3-70-g09d2 From 0e31e3573f0cd94d7b821117db854187ffc85765 Mon Sep 17 00:00:00 2001 From: Brendan Higgins Date: Thu, 12 Dec 2019 16:35:22 -0800 Subject: lkdtm/bugs: fix build error in lkdtm_UNSET_SMEP MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Acked-by: Kees Cook Link: https://lore.kernel.org/r/20191213003522.66450-1-brendanhiggins@google.com Signed-off-by: Greg Kroah-Hartman --- drivers/misc/lkdtm/bugs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/misc') diff --git a/drivers/misc/lkdtm/bugs.c b/drivers/misc/lkdtm/bugs.c index 9eda771d3a37..de87693cf557 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 +#if IS_ENABLED(CONFIG_X86_64) && !IS_ENABLED(CONFIG_UML) #define MOV_CR4_DEPTH 64 void (*direct_write_cr4)(unsigned long val); unsigned char *insn; -- cgit v1.2.3-70-g09d2