On Tue, Jun 3, 2014 at 4:11 PM, Uwe Kleine-König <[email protected]> wrote: >> I did that same change for m68k in commit cc24c40 ("m68knommu: remove >> size limit on non-MMU TASK_SIZE"). For similar reasons as you need to >> now. > ok. > >> >>Thoughts? >> >The problem is that current linus/master (and also next) doesn't boot on >> >my ARM-nommu machine because the user string functions (strnlen_user, >> >strncpy_from_user et al.) refuse to work on strings above TASK_SIZE >> >which in my case also includes the XIP kernel image. >> >> I seem to recall that we were not considering flash or anything else >> other than RAM when defining that original TASK_SIZE (back many, many >> years ago). Some of the address checks you list above made some sense >> if you had everything in RAM (though only upper bounds are checked). >> The thinking was some checking is better than none I suppose. > What is the actual meaning of TASK_SIZE? The maximal value of a valid > userspace address?
Yes $ git show cc24c40 commit cc24c405949e3d4418a90014d10166679d78141a Author: Greg Ungerer <[email protected]> Date: Mon May 24 11:22:05 2010 +1000 m68knommu: remove size limit on non-MMU TASK_SIZE The TASK_SIZE define is used in some places as a limit on the size of the virtual address space of a process. On non-MMU systems those addresses used in comparison will be physical addresses, and they could be anywhere in the 32bit physical address space. So for !CONFIG_MMU systems set the TASK_SIZE to the maximum physical address. Signed-off-by: Greg Ungerer <[email protected]> Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected] In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
