Commit graph

4 commits

Author SHA1 Message Date
Stefano Brivio
daf8d057ce seccomp: Introduce mechanism to allow per-arch syscalls
Some C library functions are commonly implemented by different syscalls
on different architectures. Add a mechanism to allow selected syscalls
for a single architecture, syntax in #syscalls comment is:

	#syscalls <arch>:<name>

e.g. s390x:socketcall, given that socketcall() is commonly used there
instead of socket().

This is now implemented by a compiler probe for syscall numbers,
auditd tools (ausyscall) are not required anymore as a result.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-01-26 16:29:34 +01:00
Stefano Brivio
fa7e2e7016 Makefile, seccomp: Fix build for i386, ppc64, ppc64le
On some distributions, on ppc64, ulimit -s returns 'unlimited': add a
reasonable default, and also make sure ulimit is invoked using the
default shell, which should ensure ulimit is actually implemented.

Also note that AUDIT_ARCH doesn't follow closely the naming reported
by 'uname -m': convert for i386 and ppc as needed.

While at it, move inclusion of seccomp.h after util.h, the former is
less generic (cosmetic/clang-tidy only).

Older kernel headers might lack a definition for AUDIT_ARCH_PPC64LE:
define that explicitly if it's not available.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-01-26 07:57:09 +01:00
Stefano Brivio
819d13bb92 seccomp.sh: Handle missing ausyscall(8) or unknown syscall number
...try sourcing it with the compiler from <sys/syscalls.h> before
giving up.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-10-21 01:21:26 +02:00
Stefano Brivio
66d5930ec7 passt, pasta: Add seccomp support
List of allowed syscalls comes from comments in the form:
	#syscalls <list>

for syscalls needed both in passt and pasta mode, and:
	#syscalls:pasta <list>
	#syscalls:passt <list>

for syscalls specifically needed in pasta or passt mode only.

seccomp.sh builds a list of BPF statements from those comments,
prefixed by a binary search tree to keep lookup fast.

While at it, clean up a bit the Makefile using wildcards.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2021-10-14 13:15:46 +02:00