Re: Remove ioctl-based procfs support on Solaris

[Pedro Alves <palves@redhat.com>]

On 09/26/2017 01:23 PM, Rainer Orth wrote:
> This is the previously mentioned patch to get rid of
> unstructured/ioctl-based procfs support in procfs.c.  Given that support
> for structured procfs was introduced in Solaris 2.6 back in 1997 and
> we're just removing support for Solaris < 10, there's no point in
> carrying that baggage (and tons of support for IRIX and OSF/11 as well)
> around any longer.
> 
> Most of the patch should be straightforward (removing support for
> !NEW_PROC_API, non-Solaris OSes and pre-Solaris 10 quirks).
> 
> Only a few points need explanations:
> 
> * <sys/syscall.h> was already included unconditionally in most places,
>   so there's no need to have guards in a few remaining ones.
> 
> * configure.host already obsoletes i?86-*-sysv4.2, i?86-*-sysv5, so
>   NEW_PROC_API detection for those in configure.ac can go.
> 
> * I'm still including <sys/procfs.h> with #define _STRUCTURED_PROC 1.
>   Theoretically, it would be better to include <procfs.h> on Solaris
>   (which includes that define), but that breaks the build over
>   <procfs.h> vs. gdb's "procfs.h", and doesn't exist on Linux.
> 
> * I've regenerated syscall_table[] in proc-events.c with a small script
>   from Solaris 10, 11.3, 11.4 <sys/syscall.h>, so there should be no
>   traces of older Solaris versions and other OSes left.
> 
> * prsysent_t and DYNAMIC_SYSCALLS was only used for AIX 5, but AIX
>   doesn't use procfs.c any longer, so all related code can go.
> 
> The patch was generated with diff -w so one can easier see changes
> without being distracted by simple reindentations.
> 

Awesome, perfect intro.  You've preemptively answered any question
that I might have.  And thanks much for diff -w!

> So far, it has only been compiled and smoke-tested on
> amd64-pc-solaris2.1[01], sparcv9-sun-solaris2.1[01], and
> x86_64-pc-linux-gnu.  Certainly needs more testing (Solaris 11.3
> vs. 11.4, 32-bit gdb, testsuite once I've figured out what's wrong on
> Solaris 10 etc.), but it's enough to get a first impression how much
> cleanup is possible here.

Hurray!

This all looks good to me FWIW, with a couple tiny nits below.

>     /proc file system, which is used on many versions of Unix
>     as a means for debuggers to control other processes.

Could you update this comment in procfs.c to mention Solaris
explicitly, please?  Likewise the first line of the file.

>  
> -   Examples of the systems that use this interface are:
> -
> -     Irix
> -     Solaris
> -     OSF
> -     AIX5

...

> -   There are three methods for doing this function:
> -   1) Newest: read/write [PCSET/PCRESET/PCUNSET]
> -      [Sol6, Sol7, UW]
> -   2) Middle: PIOCSET/PIOCRESET
> -      [Irix, Sol5]
> -   3) Oldest: PIOCSFORK/PIOCRFORK/PIOCSRLC/PIOCRRLC
> -      [OSF, Sol5]
> -
> -   Note: Irix does not define PR_ASYNC.
> -   Note: OSF  does not define PR_KLC.
> -   Note: OSF  is the only one that can ONLY use the oldest method.
> +   This function is done using read/write [PCSET/PCRESET/PCUNSET] [Sol6, Sol7].

I think the "[Sol6, Sol7]" above referred to Solaris 2.6-7.
Should we remove that?

Thanks,
Pedro Alves