Date: Wed, 10 Mar 2010 22:24:58 +0200 From: Kostik Belousov <kostikbel@gmail.com> To: Nathan Whitehorn <nwhitehorn@freebsd.org> Cc: freebsd-emulation@freebsd.org, freebsd-amd64@freebsd.org, John Baldwin <jhb@freebsd.org>, freebsd-ia64@freebsd.org Subject: Re: Request for review/comments: 32-bit compat for non-x86 architectures Message-ID: <20100310202458.GG2489@deviant.kiev.zoral.com.ua> In-Reply-To: <4B97C0FC.4020209@freebsd.org> References: <4B971CA3.9090301@freebsd.org> <201003100810.10696.jhb@freebsd.org> <4B97AF13.5040104@freebsd.org> <201003101043.23275.jhb@freebsd.org> <4B97C0FC.4020209@freebsd.org>
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[-- Attachment #1 --] On Wed, Mar 10, 2010 at 09:55:40AM -0600, Nathan Whitehorn wrote: > John Baldwin wrote: > >On Wednesday 10 March 2010 9:39:15 am Nathan Whitehorn wrote: > > > >>John Baldwin wrote: > >> > >>>On Tuesday 09 March 2010 11:14:27 pm Nathan Whitehorn wrote: > >>> > >>> > >>>>The patch at > >>>>http://people.freebsd.org/~nwhitehorn/compat_freebsd32.diff > >>>>(pre-generated freebsd32 syscalls stuff is included, which will be done > >>>>in two steps on commit) provides groundwork for supporting 32-bit > >>>>compatibility for 64-bit MIPS and PowerPC systems. It has been tested > >>>>on amd64 and powerpc64, and compile-tested on ia64. There are two main > >>>>parts to the patch: > >>>> > >>>>1) COMPAT_IA32 is renamed COMPAT_FREEBSD32, in analogy to > >>>>COMPAT_LINUX32, etc. This requires updating kernel configurations, but > >>>>is less painful than filling machine-independent bits of the kernel > >>>>with #if defined(COMPAT_IA32) || defined(COMPAT_PPC32) || > >>>>defined(COMPAT_MIPS32) || ..., and is no less descriptive than the old > >>>>name. > >>>> > >>>>2) Modifications to the freebsd32 compat layer to support big-endian > >>>>architectures. > >>>> > >>>>I would appreciate any comments, bugs, or test results on ia64. > >>>> > >>>> > >>>This doesn't look right for non-x86 32-bit ABIs: > >>> > >>>Index: sys/kern/imgact_elf.c > >>>=================================================================== > >>>--- sys/kern/imgact_elf.c (revision 204681) > >>>+++ sys/kern/imgact_elf.c (working copy) > >>>@@ -1439,7 +1439,7 @@ > >>> ehdr->e_ident[EI_ABIVERSION] = 0; > >>> ehdr->e_ident[EI_PAD] = 0; > >>> ehdr->e_type = ET_CORE; > >>>-#if defined(COMPAT_IA32) && __ELF_WORD_SIZE == 32 > >>>+#if defined(COMPAT_FREEBSD32) && __ELF_WORD_SIZE == 32 > >>> ehdr->e_machine = EM_386; > >>> #else > >>> ehdr->e_machine = ELF_ARCH; > >>> > >>> > >>Good catch! Such are the dangers of sed. How about defining an > >>ELF_ARCH32 in machine/elf.h for this case? > >> > > > >Yes, that sounds good. > > > > > >>>It would be nice to eliminate having <compat/ia32*> includes in MI code > >>>by instead including those headers in appropriate headers in > >>><machine/*>. For example, we could change <machine/reg.h> on amd64 and > >>>ia64 to include these headers, perhaps under an #ifdef COMPAT_FREEBSD32. > >>> > >>>Hmm, actually, I'm quite convinced now that <machine/reg.h> for ia64 and > >>>amd64 should include <compat/ia32/ia32_reg.h> in the #ifdef _KERNEL > >>>section to avoid polluting those includes in MI code. I'm not sure what > >>>the various <machine/fpu.h> includes are for, but fixing ia32_reg.h > >>>would be a good first step. It would make your diffs smaller I think. > >>> > >>> > >>This is how it works on powerpc64. I didn't modify amd64 and ia64 in > >>order to avoid making too many changes, but I think you're right that > >>this is a good idea. I'll add that to the patch when fixing the EM_386 > >>bit you pointed out above. > >> > > > >Ok, thanks. > > > > > I've updated the patch to incorporate these two changes, at > http://people.freebsd.org/~nwhitehorn/compat_freebsd32_2.diff. Due to > recursive inclusion issues with sys/procfs.h, it also moves prstatus32 > and friends to compat/freebsd32/freebsd32.h from ia32_reg.h. They are > MI, and seems like a more appropriate place for them anyway. First chunk for the sys_generic.c about ibits/obits looks like a bug fix ? If yes, it probably would make sense to commit it separately to be able to MFC it. The same note about chunks that remove #include <compat/ia32...>, if possible ? [-- Attachment #2 --] -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (FreeBSD) iEYEARECAAYFAkuYABkACgkQC3+MBN1Mb4i05gCg1vQsucGORz01W+nvgVl0pTTg zQ4AoILaoHaEBCSDcNkMAfqWeEbhTv2g =80ld -----END PGP SIGNATURE-----
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