Re: bad {MIN}SIGSTKSZ on debian glibc-2.2.5-14.3

[GOTO Masanori <gotom@debian.or.jp>]

At Wed, 22 Jan 2003 08:40:27 -0800,
David Mosberger wrote:
> >>>>> On Wed, 22 Jan 2003 18:30:57 +0900, GOTO Masanori <gotom@debian.or.jp> said:
> 
>   Goto> At Wed, 22 Jan 2003 07:27:41 +0800,
>   Goto> Bdale Garbee wrote:
>   >> 
>   >> I don't know anything about this header file offhand...  Could someone 
>   >> investigate and give us an answer, please?
>   >> 
>   >> Bdale, at Linux Conf Australia this week
>   >> 
>   >> 
>   >> From: David Mosberger <davidm@napali.hpl.hp.com>
>   >> Subject: [ia64 R&D] bad {MIN}SIGSTKSZ on debian glibc-2.2.5-14.3
>   >> 
>   >> It appears that Debian/stable ships with a stale header file:
>   >> /usr/include/bits/sigstack.h, contains:
>   >> 
>   >> #define MINSIGSTKSZ	2048
>   >> #define SIGSTKSZ	8192
>   >> 
>   >> These values are far too small and should be replaced with:
>   >> 
>   >> #define MINSIGSTKSZ	131027
>   >> #define SIGSTKSZ	262144
>   >> 
>   >> I think this headerfile has been corrected for "unstable" already, but
>   >> since this is effectively an ABI-change, it would be good to fix it in
>   >> "stable" too.
>   >> 
>   >> Can do?
> 
>   Goto> It's already in glibc-2.3.1-10.
> 
> Yes, of course.  I said that much.  The point is that people who use
> "stable" for development work will continue to produce "bad" binaries.
> That why I think it should be fixed for "stable" as well.

Ah, I see.  But... is it critical thing to replace "stable" package?
Changing Debian "stable" release is something high barrier...
I don't know current IA-64 really needs such change or not, so I
would like to know this change is "indispensable".

>   Goto> /* Minimum stack size for a signal handler.  */
>   Goto> #define MINSIGSTKSZ     131027
> 
>   Goto> /* System default stack size.  */
>   Goto> #define SIGSTKSZ        262144
>
>   Goto> However, I don't know why such big size is needed...
> 
> I assume you realize that these are platform-specific header files?
> On ia64 (which is what we're talking about here), the values need to
> be relatively big because the architecture allows for up to ~16KB of
> register-state.  No current ia64 chip implements that many registers,
> but with the stack size, you definitely want to err on the side of
> safety and make it rather too big than too small.

Ah, that makes sense for me.  BTW, I would like to know that how many
registers the current IA64 (Itanium/Itanium2) has?

Regards,
-- gotom