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| author | Tyler Hicks <tyhicks@canonical.com> | 2017-08-11 06:33:52 +0200 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2017-08-14 22:46:43 +0200 |
| commit | 8e5f1ad116df6b0de65eac458d5e7c318d1c05af (patch) | |
| tree | 88e0c7fe5c3a8099c65d70a4a54562ce37ff4887 /Documentation | |
| parent | seccomp: Provide matching filter for introspection (diff) | |
| download | linux-8e5f1ad116df6b0de65eac458d5e7c318d1c05af.tar.xz linux-8e5f1ad116df6b0de65eac458d5e7c318d1c05af.zip | |
seccomp: Sysctl to display available actions
This patch creates a read-only sysctl containing an ordered list of
seccomp actions that the kernel supports. The ordering, from left to
right, is the lowest action value (kill) to the highest action value
(allow). Currently, a read of the sysctl file would return "kill trap
errno trace allow". The contents of this sysctl file can be useful for
userspace code as well as the system administrator.
The path to the sysctl is:
/proc/sys/kernel/seccomp/actions_avail
libseccomp and other userspace code can easily determine which actions
the current kernel supports. The set of actions supported by the current
kernel may be different than the set of action macros found in kernel
headers that were installed where the userspace code was built.
In addition, this sysctl will allow system administrators to know which
actions are supported by the kernel and make it easier to configure
exactly what seccomp logs through the audit subsystem. Support for this
level of logging configuration will come in a future patch.
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/sysctl/kernel.txt | 1 | ||||
| -rw-r--r-- | Documentation/userspace-api/seccomp_filter.rst | 16 |
2 files changed, 17 insertions, 0 deletions
diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index bac23c198360..995c42cf86ba 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt @@ -74,6 +74,7 @@ show up in /proc/sys/kernel: - reboot-cmd [ SPARC only ] - rtsig-max - rtsig-nr +- seccomp/ ==> Documentation/userspace-api/seccomp_filter.rst - sem - sem_next_id [ sysv ipc ] - sg-big-buff [ generic SCSI device (sg) ] diff --git a/Documentation/userspace-api/seccomp_filter.rst b/Documentation/userspace-api/seccomp_filter.rst index f71eb5ef1f2d..35fc7cbf1d95 100644 --- a/Documentation/userspace-api/seccomp_filter.rst +++ b/Documentation/userspace-api/seccomp_filter.rst @@ -169,7 +169,23 @@ The ``samples/seccomp/`` directory contains both an x86-specific example and a more generic example of a higher level macro interface for BPF program generation. +Sysctls +======= + +Seccomp's sysctl files can be found in the ``/proc/sys/kernel/seccomp/`` +directory. Here's a description of each file in that directory: + +``actions_avail``: + A read-only ordered list of seccomp return values (refer to the + ``SECCOMP_RET_*`` macros above) in string form. The ordering, from + left-to-right, is the least permissive return value to the most + permissive return value. + The list represents the set of seccomp return values supported + by the kernel. A userspace program may use this list to + determine if the actions found in the ``seccomp.h``, when the + program was built, differs from the set of actions actually + supported in the current running kernel. Adding architecture support =========================== |