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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | EXAMPLES | NOTES | AUTHOR | SEE ALSO | COLOPHON |
seccomp_syscall_priority(3)ibseccomp Documentationeccomp_syscall_priority(3)
seccomp_syscall_priority - Prioritize syscalls in the seccomp filter
#include <seccomp.h>
typedef void * scmp_filter_ctx;
int SCMP_SYS(syscall_name);
int seccomp_syscall_priority(scmp_filter_ctx ctx,
int syscall, uint8_t priority);
Link with -lseccomp.
The seccomp_syscall_priority() function provides a priority hint to
the seccomp filter generator in libseccomp such that higher priority
syscalls are placed earlier in the seccomp filter code so that they
incur less overhead at the expense of lower priority syscalls. A
syscall's priority can be set regardless of if any rules currently
exist for that syscall; the library will remember the priority and it
will be assigned to the syscall if and when a rule for that syscall
is created.
While it is possible to specify the syscall value directly using the
standard __NR_syscall values, in order to ensure proper operation
across multiple architectures it is highly recommended to use the
SCMP_SYS() macro instead. See the EXAMPLES section below.
The priority parameter takes an 8-bit value ranging from 0 - 255; a
higher value represents a higher priority.
The filter context ctx is the value returned by the call to
seccomp_init().
The seccomp_syscall_priority() function returns zero on success,
negative errno values on failure. The SCMP_SYS() macro returns a
value suitable for use as the syscall value in
seccomp_syscall_priority().
#include <seccomp.h>
int main(int argc, char *argv[])
{
int rc = -1;
scmp_filter_ctx ctx;
ctx = seccomp_init(SCMP_ACT_KILL);
if (ctx == NULL)
goto out;
/* ... */
rc = seccomp_syscall_priority(ctx, SCMP_SYS(read), 200);
if (rc < 0)
goto out;
/* ... */
out:
seccomp_release(ctx);
return -rc;
}
While the seccomp filter can be generated independent of the kernel,
kernel support is required to load and enforce the seccomp filter
generated by libseccomp.
The libseccomp project site, with more information and the source
code repository, can be found at
https://github.com/seccomp/libseccomp. This tool, as well as the
libseccomp library, is currently under development, please report any
bugs at the project site or directly to the author.
Paul Moore <paul@paul-moore.com>
seccomp_rule_add(3), seccomp_rule_add_exact(3)
This page is part of the libseccomp (high-level API to the Linux
Kernel's seccomp filter) project. Information about the project can
be found at ⟨https://github.com/seccomp/libseccomp⟩. If you have a
bug report for this manual page, see
⟨https://groups.google.com/d/forum/libseccomp⟩. This page was
obtained from the project's upstream Git repository
⟨https://github.com/seccomp/libseccomp⟩ on 2017-07-05. If you dis‐
cover any rendering problems in this HTML version of the page, or you
believe there is a better or more up-to-date source for the page, or
you have corrections or improvements to the information in this
COLOPHON (which is not part of the original manual page), send a mail
to man-pages@man7.org
paul@paul-moore.com 25 July 2012 seccomp_syscall_priority(3)
Pages that refer to this page: seccomp_rule_add(3)