path: root/include/asm-sh
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authorPaul Mundt <lethal@linux-sh.org>2008-05-19 13:34:45 +0900
committerPaul Mundt <lethal@linux-sh.org>2008-07-28 18:10:28 +0900
commit9b14ec35f03d89c88cba225add8b6eca15203964 (patch)
tree9502e80206d3e1ead9a0c553f9f719b99c0ceebd /include/asm-sh
parente3b08600902e119b34ca03c4aaf99bde4b173dde (diff)
binfmt_elf_fdpic: Magical stack pointer index, for NEW_AUX_ENT compat.
While implementing binfmt_elf_fdpic on SH it quickly became apparent that SH was the first platform to support both binfmt_elf_fdpic and binfmt_elf, as well as the only of the FDPIC platforms to make use of the auxvt. Currently binfmt_elf_fdpic uses a special version of NEW_AUX_ENT() where the first argument is the entry displacement after csp has been adjusted, being reset after each adjustment. As we have no ability to sort this out through the platform's ARCH_DLINFO, this index needs to be managed entirely in create_elf_fdpic_tables(). Presently none of the platforms that set their own auxvt entries are able to do so through their respective ARCH_DLINFOs when using binfmt_elf_fdpic. In addition to this, binfmt_elf_fdpic has been looking at DLINFO_ARCH_ITEMS for the number of architecture-specific entries in the auxvt. This is legacy cruft, and is not defined by any platforms in-tree, even those that make heavy use of the auxvt. AT_VECTOR_SIZE_ARCH is always available, and contains the number that is of interest here, so we switch to using that unconditionally as well. As this has direct bearing on how much stack is used, platforms that have configurable (or dynamically adjustable) NEW_AUX_ENT calls need to either make AT_VECTOR_SIZE_ARCH more fine-grained, or leave it as a worst-case and live with some lost stack space if those entries aren't pushed (some platforms may also need to purposely sacrifice some space here for alignment considerations, as noted in the code -- although not an issue for any FDPIC-capable platform today). Signed-off-by: Paul Mundt <lethal@linux-sh.org> Acked-by: David Howells <dhowells@redhat.com>
Diffstat (limited to 'include/asm-sh')
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