ausyscall Command in Linux
ausyscall is a command used in Linux to map system call numbers to their corresponding numbers and vice versa. This command is pretty useful for auditing and debugging that requires specifying an architecture (like x86_64 or i386) to get the correct mapping for that system.
If you provide a system call name, ausyscall will return its number and in case you provide a number, it will return the name.
Table of Contents
Here is a comprehensive guide to the options available with the ausyscall command in linux −
Syntax for ausyscall Command
The basic syntax to use the ausyscall in Linux is provided below −
ausyscall [options] [arch] [syscall]
- options are various options you can use with the command.
- arch is the architecture you are targeting, like x86_64 or i386.
- syscall is the system call name or number you want to look up.
ausyscall Command Options
The following table enlists different options you can use with the ausyscall command on Linux system −
| Option | Description |
|---|---|
| --arch | Specifies the architecture (e.g., x86_64, i386) for which to list system calls. |
| --dump | Lists all system calls for the specified architecture. |
| --exact | Performs an exact match for the given system call name or number. |
| --help | Displays help information about the command and its usage. |
| --version | Shows the version information of the command. |
Examples of ausyscall Command in Linux
Lets discuss a few examples of ausyscall commands in Linux systems. This will help you in learning how to get started with the command.
- List All System Call for a Specific Architecture
- Find the System Call Number for a Specific Call
- Find the System Call Name for a Specific Number
- Perform an Exact Match for a System Call Name
List All System Calls for a Specific Architecture
One of the basic uses of ausyscall is to list all system calls for a specific architecture. To do this, you can execute the following command −
ausyscall --dump x86_64
Once you run the above command, it will provide a list of all system calls for the x86_64 architecture and help you understand the available system calls.
Find the System Call Number for a Specific Call
With the ausyscall command, you can also find the system call number for a specific call. This is useful for debugging and auditing purposes, and it can be done using the below-given command −
ausyscall x86_64 open
This command will return the system call number for open in the x86_64 architecture.
Find the System Call Name for a Specific Number
It is also possible to find the system call name for a specific number using the ausyscall command. To do this, you can execute the following command −
ausyscall x86_64 4
When the above command is executed, it will return the system call name for the number 4 in the x86_64 architecture.
Perform an Exact Match for a System Call Name
You can also perform an exact match for a system call name using the ausyscall command. This is useful when you need precise information, and it can be done using the below-provided command −
ausyscall --exact x86_64 open
The above command will ensure an exact match for the open system call in the x86_64 architecture.
Thats how you can use the ausyscall command in your Linux system.
Conclusion
The ausyscall command is a valuable tool in Linux for mapping system call names to their corresponding numbers and vice versa. This command is pretty useful for auditing and debugging, and needs a specific architecture (like x86_64, arm, or i386) to get the correct mapping.
In this tutorial, we explored the basic syntax of ausyscall command along with some options that can be used with it. Further, a few practical examples are provided as well to illustrate its usage. By following these examples, you should now have a solid understanding of how to use the ausyscall command effectively on your Linux system.