ausyscall

Display syscall number of a specific system call

$ ausyscall [search_pattern]

$ ausyscall [system_call_number]

$ ausyscall [architecture] --dump

ausyscall [arch] name | number | --dump | --exact

ausyscall is a program that prints out the mapping from syscall name to number and reverse for the given arch. The arch can be anything returned by `uname -m`. If arch is not given, the program will take a guess based on the running image. Or for convenience, you can pass b32 or b64 to use the current arch but a specific ABI. You may give the syscall name or number and it will find the opposite. You can also dump the whole table with the --dump option. By default a syscall name lookup will be a substring match meaning that it will try to match all occurrences of the given name with syscalls. So giving a name of chown will match both fchown and chown as any other syscall with chown in its name. If this behavior is not desired, pass the --exact flag and it will do an exact string match.

The program takes the special arch, uring, to denote that you want to specify io_uring operations. In this case, the arch must be given because it will otherwise detect the underlying harware.

This program can be used to verify syscall numbers on a biarch platform for rule optimization. For example, suppose you had an auditctl rule:

-a always, exit -S open -F exit=-EPERM -k fail-open

If you wanted to verify that both 32 and 64 bit programs would be audited, run "ausyscall i386 open" and then "ausyscall x86_64 open". (Or use the b32 and b64 option.) Look at the returned numbers. If they are different, you will have to write two auditctl rules to get complete coverage.

-a always,exit -F arch=b32 -S open -F exit=-EPERM -k fail-open
-a always,exit -F arch=b64 -S open -F exit=-EPERM -k fail-open

For more information about a specific syscall, use the man program and pass the number 2 as an argument to make sure that you get the syscall information rather than a shell script program or glibc function call of the same name. For example, if you wanted to learn about the open syscall, type: man 2 open.

--dump

Print all syscalls for the given arch

--exact

Instead of doing a partial word match, match the given syscall name exactly.

ausearch(8), auditctl(8).

Steve Grubb