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

[David Mosberger <davidm@napali.hpl.hp.com>]

>>>>> 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.

  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.

	--david