Re: Formal description of system call interface

From: Szabolcs Nagy
Date: Sun Nov 06 2016 - 19:34:52 EST


* Dmitry Vyukov <dvyukov@xxxxxxxxxx> [2016-11-06 14:39:28 -0800]:
> This is notes from the discussion we had at Linux Plumbers this week
> regarding providing a formal description of system calls (user API).

yes a database of the syscall abis would be useful
..depending on the level of detail it has.

(right now there is not even spec about what registers
the syscall entry point may clobber on the various abis
which would be useful to know when making syscalls)

> Action points:
> - polish DSL for description (must be extensible)
> - write a parser for DSL
> - provide definition for mm syscalls (mm is reasonably simple
> and self-contained)
> - see if we can do validation of mm arguments

for all abi variants? e.g. mmap offset range is abi dependent.

> For the reference, current syzkaller descriptions are in txt files here:
> https://github.com/google/syzkaller/tree/master/sys
...
> Taking the opportunity, if you see that something is missing/wrong
> in the descriptions of the subsystem you care about, or if it is not
> described at all, fixes are welcome.

abi variants are missing (abi variation makes a lot of
syscall interface related work painful).