This change fixes the compilation error triggered here for i386 allmodconfig in linux-next: http://kisskb.ellerman.id.au/kisskb/buildresult/6123842/ Logic attempting to predict the host architecture has been removed from the Makefile. Instead, the bpf-direct sample should now compile on any architecture, but if the architecture is not supported, it will compile a minimal main() function. This change also ensures the samples are not compiled when there is no seccomp filter support. (Note, I wasn't able to reproduce the error locally, but the existing approach was clearly flawed. This tweak should resolve your issue and avoid other future weirdness.) Reported-by: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx> Suggested-by: Kees Cook <keescook@xxxxxxxxxxxx> Signed-off-by: Will Drewry <wad@xxxxxxxxxxxx> --- samples/seccomp/Makefile | 12 +++--------- samples/seccomp/bpf-direct.c | 18 ++++++++++++++++-- 2 files changed, 19 insertions(+), 11 deletions(-) diff --git a/samples/seccomp/Makefile b/samples/seccomp/Makefile index e8fe0f5..16aa2d4 100644 --- a/samples/seccomp/Makefile +++ b/samples/seccomp/Makefile @@ -1,27 +1,21 @@ # kbuild trick to avoid linker error. Can be omitted if a module is built. obj- := dummy.o -hostprogs-$(CONFIG_SECCOMP) := bpf-fancy dropper -bpf-fancy-objs := bpf-fancy.o bpf-helper.o +hostprogs-$(CONFIG_SECCOMP_FILTER) := bpf-fancy dropper bpf-direct HOSTCFLAGS_bpf-fancy.o += -I$(objtree)/usr/include HOSTCFLAGS_bpf-fancy.o += -idirafter $(objtree)/include HOSTCFLAGS_bpf-helper.o += -I$(objtree)/usr/include HOSTCFLAGS_bpf-helper.o += -idirafter $(objtree)/include +bpf-fancy-objs := bpf-fancy.o bpf-helper.o HOSTCFLAGS_dropper.o += -I$(objtree)/usr/include HOSTCFLAGS_dropper.o += -idirafter $(objtree)/include dropper-objs := dropper.o -# bpf-direct.c is x86-only. -ifeq ($(SRCARCH),x86) -# List of programs to build -hostprogs-$(CONFIG_SECCOMP) += bpf-direct -bpf-direct-objs := bpf-direct.o -endif - HOSTCFLAGS_bpf-direct.o += -I$(objtree)/usr/include HOSTCFLAGS_bpf-direct.o += -idirafter $(objtree)/include +bpf-direct-objs := bpf-direct.o # Try to match the kernel target. ifeq ($(CONFIG_64BIT),) diff --git a/samples/seccomp/bpf-direct.c b/samples/seccomp/bpf-direct.c index 26f523e..151ec3f 100644 --- a/samples/seccomp/bpf-direct.c +++ b/samples/seccomp/bpf-direct.c @@ -8,6 +8,11 @@ * and can serve as a starting point for developing * applications using prctl(PR_SET_SECCOMP, 2, ...). */ +#if defined(__i386__) || defined(__x86_64__) +#define SUPPORTED_ARCH 1 +#endif + +#if defined(SUPPORTED_ARCH) #define __USE_GNU 1 #define _GNU_SOURCE 1 @@ -43,8 +48,6 @@ #define REG_ARG3 REG_R10 #define REG_ARG4 REG_R8 #define REG_ARG5 REG_R9 -#else -#error Unsupported platform #endif #ifndef PR_SET_NO_NEW_PRIVS @@ -174,3 +177,14 @@ int main(int argc, char **argv) payload("Error message going to STDERR\n")); return 0; } +#else /* SUPPORTED_ARCH */ +/* + * This sample is x86-only. Since kernel samples are compiled with the + * host toolchain, a non-x86 host will result in using only the main() + * below. + */ +int main(void) +{ + return 1; +} +#endif /* SUPPORTED_ARCH */ -- 1.7.5.4 -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
