Re: [PATCHv2] ARM64:Fix MINSIGSTKSZ and SIGSTKSZ

From	Dave Martin <Dave.Martin@arm.com>
Newsgroups	linux.kernel
Subject	Re: [PATCHv2] ARM64:Fix MINSIGSTKSZ and SIGSTKSZ
Date	2015-10-12 16:00 +0200
Message-ID	<qiLNV-LL-53@gated-at.bofh.it> (permalink)
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On Fri, Oct 09, 2015 at 10:41:43AM +0200, Arnd Bergmann wrote:
> On Tuesday 06 October 2015 12:51:24 Arnd Bergmann wrote:
> > 
> > I think it makes sense to stick with the traditional definition
> > of MINSIGSTKSZ == "the minimum amount that you will always need,
> > add whatever you require yourself" and SIGSTKSZ == "Should be
> > enough for a couple of function calls". If we want to be conservative
> > in the kernel, using 8192 and 32768, to stay with the x4 ratio
> > that everyone else uses would be my first pick, though I'm not
> > particularly attached to those values.
> > 
> > 
> 
> On second thought, it really seems to late to make up our minds
> about the size now that glibc has already established 5KB as the
> minimum size. If we set it to 8KB/32KB, not just the testcase but
> real applications would start failing when they use the 5KB
> constant from glibc.

I agree for MINSIGSTKSZ.  We could still raise SIGSTKSZ if we think
that will be more future-proof (SIGSTKSZ would be less than the magic
4*MINSIGSTKSZ that most arches assume, unless SIGSTKSZ is made >=20KB).

Those might be independent changes.  The definition of MINSIGSTKSZ
is definitely broken right now, whereas SIGSTKSZ could be debated,
but isn't actually broken.

Cheers
---Dave

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Thread

[PATCHv2] ARM64:Fix MINSIGSTKSZ and SIGSTKSZ Manjeet Pawar <manjeet.p@samsung.com> - 2015-10-06 07:40 +0200
  Re: [PATCHv2] ARM64:Fix MINSIGSTKSZ and SIGSTKSZ Arnd Bergmann <arnd@arndb.de> - 2015-10-06 09:50 +0200
    Re: [PATCHv2] ARM64:Fix MINSIGSTKSZ and SIGSTKSZ Catalin Marinas <catalin.marinas@arm.com> - 2015-10-06 11:40 +0200
    Re: [PATCHv2] ARM64:Fix MINSIGSTKSZ and SIGSTKSZ Dave Martin <Dave.Martin@arm.com> - 2015-10-06 12:40 +0200
      Re: [PATCHv2] ARM64:Fix MINSIGSTKSZ and SIGSTKSZ Andreas Schwab <schwab@suse.de> - 2015-10-06 13:00 +0200
        Re: [PATCHv2] ARM64:Fix MINSIGSTKSZ and SIGSTKSZ Dave Martin <Dave.Martin@arm.com> - 2015-10-06 13:40 +0200
          Re: [PATCHv2] ARM64:Fix MINSIGSTKSZ and SIGSTKSZ Andreas Schwab <schwab@suse.de> - 2015-10-06 14:00 +0200
            Re: [PATCHv2] ARM64:Fix MINSIGSTKSZ and SIGSTKSZ Dave Martin <Dave.Martin@arm.com> - 2015-10-06 14:50 +0200
      Re: [PATCHv2] ARM64:Fix MINSIGSTKSZ and SIGSTKSZ Arnd Bergmann <arnd@arndb.de> - 2015-10-06 13:00 +0200
        Re: [PATCHv2] ARM64:Fix MINSIGSTKSZ and SIGSTKSZ Dave Martin <Dave.Martin@arm.com> - 2015-10-06 13:30 +0200
        Re: [PATCHv2] ARM64:Fix MINSIGSTKSZ and SIGSTKSZ Arnd Bergmann <arnd@arndb.de> - 2015-10-09 10:50 +0200
          Re: [PATCHv2] ARM64:Fix MINSIGSTKSZ and SIGSTKSZ Dave Martin <Dave.Martin@arm.com> - 2015-10-12 16:00 +0200
  Re: [PATCHv2] ARM64:Fix MINSIGSTKSZ and SIGSTKSZ Will Deacon <will.deacon@arm.com> - 2015-10-06 12:30 +0200

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