On Mon, 2007-05-07 at 10:46 -0700, Luck, Tony wrote:
> > We've tested the following architectures: i386, x86_64, um/i386,
> > parisc, and frv.  These are representative of the various scenarios
> > which this patch addresses, but other architecture teams should try it
> > out to make sure there aren't any unexpected gotchas.
> 
> Doesn't build on ia64: complaints from arch/ia64/ia32/binfmt_elf.c
> (which #includes ../../../fs/binfmt_elf.c) ...
> 
> arch/ia64/ia32/binfmt_elf32.c: In function `ia32_setup_arg_pages':
> arch/ia64/ia32/binfmt_elf32.c:206: error: `MAX_ARG_PAGES' undeclared (first use in this function)
> arch/ia64/ia32/binfmt_elf32.c:206: error: (Each undeclared identifier is reported only once
> arch/ia64/ia32/binfmt_elf32.c:206: error: for each function it appears in.)
> arch/ia64/ia32/binfmt_elf32.c:240: error: structure has no member named `page'
> arch/ia64/ia32/binfmt_elf32.c:242: error: structure has no member named `page'
> arch/ia64/ia32/binfmt_elf32.c:243: warning: implicit declaration of function `install_arg_page'
> make[1]: *** [arch/ia64/ia32/binfmt_elf32.o] Error 1
> 
> Turning off CONFIG_IA32-SUPPORT, the kernel built, but oops'd during boot.
> My serial connection to my test machine is currently broken, so I didn't
> get a capture of the stack trace, sorry.


Ok, I found the problem. IA64 places constraints on virtual address
space. We initially place the stack at TASK_SIZE, and once the binfmt
tells us where it should have gone, we move it down to the new location.

However IA64 has v-space carved up in regions, and the top of the user
accessible address space is reserved for hugetlbfs.

So we should be using STACK_TOP, which provides the highest stack
address, however, some arches have conditions in the STACK_TOP macros
such that the result is not what is expected until the binfmt
personality is set.

In order to solve this, I added a STACK_TOP_MAX macro for each arch and
use that. This made IA64 boot properly.

The second patch makes the compat stuff compile, untested though, as I
have no idea how that works on ia64.