On Sun, Feb 03, 2008 at 09:30:02PM +0100, Sam Ravnborg wrote: > And I'm suprised to see that gcc thinks bar is writeable. > If I try to assign it gcc error out as expected.
That's because "not modifiable" and "goes into r/o section" are not the same thing. The former belongs to C and is target-independent, of course. The latter is up to implementation, except that modifiable objects obviously *can not* go into r/o. You are not guaranteed the reverse. > We could invent a __initstr annotation but I dunno if that would suffice. > Do you see any pattern when gcc do the r/w choice compared to the > r/o choise. Maybe it is only const char[] that happens to be considered > r/o and the rest is r/w? On ppc64 relocs => r/w, AFAICS. On other targets we might have any number of other rules. > Should a gcc-bug be filed for this btw? Why? gcc is entirely within its rights - it's not even a matter of ABI, it's way below that. Note that you are meddling with section assignment rules and those are target-dependent, so target-independent overrides are nowhere near being promised to work. Frankly, "do not ever make __initdata et.al. const" is probably the best we can do - adding __initconst, __initconst_but_has_relocs, __initconst_but_has_something_that_puts_it_into_writable_on_this_weird_target, __initconst_but_has_something_that_puts_it_into_writable_on_that_weird_target, etc. is not feasible - we'll keep getting portability bugs all the time since nobody will remember all rules (or care about ones that do not apply on amd64). Suppose we have an array of ad-hoc structs with a bunch of ints in those. Used only in ->probe(), so __devinitdata. Constant, so __devinitconst (and no special per-target rules trigger on the current struct contents). Fast forward half a year; somebody adds a string field to those. Oops - suddenly it's __devinitconst_but_has_relocs, but author of that patch has never heard of ppc64 oddities; on all targets he knows __devinitconst still works fine. -- 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/
