Messages in this thread |  | | Date | Sat, 10 May 2003 16:31:56 +0100 | From | Jamie Lokier <> | Subject | Re: [PATCH] i386 uaccess to fixmap pages |
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H. Peter Anvin wrote: > Another option would be to put it in the "user" part of the address > space at 0xbffff000 (and move the %esp base value.) That would have > the nice side benefit that stuff like UML or whatever who wanted to > map something over the vsyscall could do so. Downside: each process > needs a PTE for this.
It doesn't need a PTE. The vsyscall code could be _copied_ to the end of the page at 0xbffff000, with the stack immediately preceding it.
In fact that's 1 fewer TLB entries than the current arrangement. The fork-time copy should be negligable as it is a very small code fragment.
I suspect this would cause difficulties with the latest ELF and unwind tables, but apart from that, why _not_ place the vsyscall trampoline at the end of the stack?
-- Jamie - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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