There were some bugs in the JNE64 and JLT64 comparision macros. This fixes
them, improves comments, and cleans up the file while we are at it.
Reported-by: Stephen Röttger <sroettger@google.com>
Signed-off-by: Mathias Svensson <idolf@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Signed-off-by: James Morris <james.l.morris@oracle.com>
The LO_ARG define needs to consider endianness also for 32 bit builds.
The "bpf_fancy" test case didn't work on s390 in 32 bit and compat mode
because the LO_ARG define resulted in a BPF program which read the upper
halve of the 64 bit system call arguments instead of the lower halves.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.l.morris@oracle.com>
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 <eparis@redhat.com>
Signed-off-by: Will Drewry <wad@chromium.org>
Acked-by: Kees Cook <keescook@chromium.org>
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 88ebdda615
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 <james.l.morris@oracle.com>