From f68022ae0aeb0803450e05abc0e984027c33ef1b Mon Sep 17 00:00:00 2001 From: Kristina Martsenko Date: Fri, 9 Dec 2022 17:34:41 +0000 Subject: lkdtm: cfi: Make PAC test work with GCC 7 and 8 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The CFI test uses the branch-protection=none compiler attribute to disable PAC return address protection on a function. While newer GCC versions support this attribute, older versions (GCC 7 and 8) instead supported the sign-return-address=none attribute, leading to a build failure when the test is built with older compilers. Fix it by checking which attribute is supported and using the correct one. Fixes: 2e53b877dc12 ("lkdtm: Add CFI_BACKWARD to test ROP mitigations") Reported-by: Daniel Díaz Signed-off-by: Kristina Martsenko Signed-off-by: Kees Cook Link: https://lore.kernel.org/all/CAEUSe78kDPxQmQqCWW-_9LCgJDFhAeMoVBFnX9QLx18Z4uT4VQ@mail.gmail.com/ --- drivers/misc/lkdtm/cfi.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'drivers/misc') diff --git a/drivers/misc/lkdtm/cfi.c b/drivers/misc/lkdtm/cfi.c index 5245cf6013c9..fc28714ae3a6 100644 --- a/drivers/misc/lkdtm/cfi.c +++ b/drivers/misc/lkdtm/cfi.c @@ -54,7 +54,11 @@ static void lkdtm_CFI_FORWARD_PROTO(void) # ifdef CONFIG_ARM64_BTI_KERNEL # define __no_pac "branch-protection=bti" # else -# define __no_pac "branch-protection=none" +# ifdef CONFIG_CC_HAS_BRANCH_PROT_PAC_RET +# define __no_pac "branch-protection=none" +# else +# define __no_pac "sign-return-address=none" +# endif # endif # define __no_ret_protection __noscs __attribute__((__target__(__no_pac))) #else -- cgit v1.2.3