linux-kernel - Re: [PATCH 3/4] rcutorture/nolibc: add a bit of documentation to explain how to use nolibc

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Message-ID: <20181229223324.slqx3qjrmzg5g2w2@gmail.com>
Date:   Sat, 29 Dec 2018 12:33:24 -1000
From:   Joey Pabalinas <joeypabalinas@...il.com>
To:     Willy Tarreau <w@....eu>
Cc:     mingo@...nel.org, paulmck@...ux.vnet.ibm.com,
        rdunlap@...radead.org, linux-kernel@...r.kernel.org,
        Joey Pabalinas <joeypabalinas@...il.com>
Subject: Re: [PATCH 3/4] rcutorture/nolibc: add a bit of documentation to
 explain how to use nolibc

On Sat, Dec 29, 2018 at 07:02:18PM +0100, Willy Tarreau wrote:
> + *   - the lower level is the arch-specific syscall() definition, consisting in
> + *     assembly code in compound expressions. These are called my_syscall0() to
> + *     my_syscall6() depending on the number of arguments. The MIPS
> + *     implementation is limited to 5 arguments. All input arguments are cast
> + *     to a long stored in a register. These expressions always return the
> + *     syscall's return value as a signed long value which is often either a
> + *     pointer or the negated errno value.
> + *
> + *   - the second level is mostly architecture-independent. It is made of
> + *     static functions called sys_<name>() which rely on my_syscallN()
> + *     depending on the syscall definition. These functions are responsible
> + *     for exposing the appropriate types for the syscall arguments (int,
> + *     pointers, etc) and for setting the appropriate return type (often int).
> + *     A few of them are architecture-specific because the syscalls are not all
> + *     mapped exactly the same among architectures. For example, some archs do
> + *     not implement select() and need pselect6() instead, so the sys_select()
> + *     function will have to abstract this.
> + *
> + *   - the third level is the libc call definition. It exposes the lower raw
> + *     sys_<name>() calls in a way that looks like what a libc usually does,
> + *     takes care of specific input values, and of setting errno upon error.
> + *     There can be minor variations compared to standard libc calls. For
> + *     example the open() call always takes 3 args here.

Shouldn't these sentences begin with a capitalized "The" for
consistency?

>  /* some archs (at least aarch64) don't expose the regular syscalls anymore by
>   * default, either because they have an "_at" replacement, or because there are
>   * more modern alternatives. For now we'd rather still use them.

Also here. Shouldn't this begin with a capitalized "Some"?

-- 
Cheers,
Joey Pabalinas

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