Gramine Use Case

[Kevin Chacon Levin]

To whom it may concern,

Hope this email finds you well.

I have a very specific need in order to use Gramine. I need to print all system calls that happen when running an application via Gramine. I'm having difficulty achieving this (bare in mind I'm not expert on this). I thought that modifying the file libos_syscalls.c and the function libos_emulate_syscall would be enough, but nothing has happened.

Can you point me in the direction of which component is in charge of intercepting systemcalls so that I can print the system call names?

Thanks so much.

Best,

Kevin

[Wojtek Porczyk]

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On Tue, Aug 08, 2023 at 03:03:59PM +0100, Kevin Chacon Levin wrote:
> I have a very specific need in order to use Gramine. I need to print all
> system calls that happen when running an application via Gramine. I'm
> having difficulty achieving this (bare in mind I'm not expert on this). I
> thought that modifying the file libos_syscalls.c and the function
> libos_emulate_syscall would be enough, but nothing has happened.
>
> Can you point me in the direction of which component is in charge of
> intercepting systemcalls so that I can print the system call names?

You can use loader.log_level="trace" in manifest, it will print all the
syscalls to stderr.
https://gramine.readthedocs.io/en/stable/manifest-syntax.html#log-level


- --
pozdrawiam / best regards
Wojtek Porczyk
Gramine / Invisible Things Lab

I do not fear computers,
I fear lack of them.
-- Isaac Asimov
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[Kenny]

Hi,

Are you referring to implement the system call? You can add the function body of libos_syscall_sched_setaffinity to implement the system call.

Refer https://gramine.readthedocs.io/en/stable/devel/new-syscall.html for more information.

Regards,
Ken

[Kevin Chacon Levin]

Hi Wojtek,

Thanks so much for your reply.

This solved my problem. Thank you again :).

Best,

Kevin