From 8ac270d1e29f0428228ab2b9a8ae5e1ed4a5cd84 Mon Sep 17 00:00:00 2001 From: Will Drewry Date: Thu, 12 Apr 2012 16:48:04 -0500 Subject: Documentation: prctl/seccomp_filter Documents how system call filtering using Berkeley Packet Filter programs works and how it may be used. Includes an example for x86 and a semi-generic example using a macro-based code generator. Acked-by: Eric Paris Signed-off-by: Will Drewry Acked-by: Kees Cook v18: - added acked by - update no new privs numbers v17: - remove @compat note and add Pitfalls section for arch checking (keescook@chromium.org) v16: - v15: - v14: - rebase/nochanges v13: - rebase on to 88ebdda6159ffc15699f204c33feb3e431bf9bdc v12: - comment on the ptrace_event use - update arch support comment - note the behavior of SECCOMP_RET_DATA when there are multiple filters (keescook@chromium.org) - lots of samples/ clean up incl 64-bit bpf-direct support (markus@chromium.org) - rebase to linux-next v11: - overhaul return value language, updates (keescook@chromium.org) - comment on do_exit(SIGSYS) v10: - update for SIGSYS - update for new seccomp_data layout - update for ptrace option use v9: - updated bpf-direct.c for SIGILL v8: - add PR_SET_NO_NEW_PRIVS to the samples. v7: - updated for all the new stuff in v7: TRAP, TRACE - only talk about PR_SET_SECCOMP now - fixed bad JLE32 check (coreyb@linux.vnet.ibm.com) - adds dropper.c: a simple system call disabler v6: - tweak the language to note the requirement of PR_SET_NO_NEW_PRIVS being called prior to use. (luto@mit.edu) v5: - update sample to use system call arguments - adds a "fancy" example using a macro-based generator - cleaned up bpf in the sample - update docs to mention arguments - fix prctl value (eparis@redhat.com) - language cleanup (rdunlap@xenotime.net) v4: - update for no_new_privs use - minor tweaks v3: - call out BPF <-> Berkeley Packet Filter (rdunlap@xenotime.net) - document use of tentative always-unprivileged - guard sample compilation for i386 and x86_64 v2: - move code to samples (corbet@lwn.net) Signed-off-by: James Morris --- samples/seccomp/Makefile | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) create mode 100644 samples/seccomp/Makefile (limited to 'samples/seccomp/Makefile') diff --git a/samples/seccomp/Makefile b/samples/seccomp/Makefile new file mode 100644 index 000000000000..e8fe0f57b68f --- /dev/null +++ b/samples/seccomp/Makefile @@ -0,0 +1,38 @@ +# kbuild trick to avoid linker error. Can be omitted if a module is built. +obj- := dummy.o + +hostprogs-$(CONFIG_SECCOMP) := bpf-fancy dropper +bpf-fancy-objs := bpf-fancy.o bpf-helper.o + +HOSTCFLAGS_bpf-fancy.o += -I$(objtree)/usr/include +HOSTCFLAGS_bpf-fancy.o += -idirafter $(objtree)/include +HOSTCFLAGS_bpf-helper.o += -I$(objtree)/usr/include +HOSTCFLAGS_bpf-helper.o += -idirafter $(objtree)/include + +HOSTCFLAGS_dropper.o += -I$(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 $(objtree)/include + +# Try to match the kernel target. +ifeq ($(CONFIG_64BIT),) +HOSTCFLAGS_bpf-direct.o += -m32 +HOSTCFLAGS_dropper.o += -m32 +HOSTCFLAGS_bpf-helper.o += -m32 +HOSTCFLAGS_bpf-fancy.o += -m32 +HOSTLOADLIBES_bpf-direct += -m32 +HOSTLOADLIBES_bpf-fancy += -m32 +HOSTLOADLIBES_dropper += -m32 +endif + +# Tell kbuild to always build the programs +always := $(hostprogs-y) -- cgit v1.2.3-59-g8ed1b