[PATCH v6 3/6] syscall.h: introduce syscall_set_nr()

Maciej W. Rozycki macro at orcam.me.uk
Wed Feb 19 19:20:33 UTC 2025


On Wed, 19 Feb 2025, Dmitry V. Levin wrote:

> >  That label is called `trace_a_syscall' in arch/mips/kernel/scall64-o32.S 
> > instead.  To bring some order and avoid an inaccuracy here should the odd 
> > one be matched to the other three?
> 
> Apparently, there are two instances of syscall_trace_entry(), one
> n32_syscall_trace_entry(), one trace_a_syscall(), and each of them
> is calling syscall_trace_enter(), not to be confused with
> syscall_trace_entry():

 Oh dear!

> I'd change the wording of my comment rather than try to disentangle this.
> After all, the most important here is that the new syscall number is
> loaded from regs[2] right after the syscall_trace_enter() invocation.

 Right.

> Would you be OK with the following wording:
> 	/*
> 	 * New syscall number has to be assigned to regs[2] because it is
> 	 * loaded from there unconditionally after syscall_trace_enter()
> 	 * invocation.

 May I suggest "[...] after return from syscall_trace_enter() invocation." 
instead?  Minor reformatting might be required for better visual alignment 
though.

  Maciej


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