[Re: [PATCH] ARM: move body of head-common.S back to text section] On 03/07/2013 (Wed 11:00) Russell King - ARM Linux wrote:
> On Wed, Jul 03, 2013 at 01:19:07AM -0400, Paul Gortmaker wrote: > > As an aside, I'm now thinking any __INIT that implicitly rely on EOF for > > closure are nasty traps waiting to happen and it might be worthwhile to > > audit and explicitly __FINIT them before someone appends to the file... > > That hides a different kind of bug though - I hate __FINIT for exactly > that reason. Consider this: Agreed - perhaps masking that it is a ".previous" just hides the fact that it is more like a pop operation vs. an on/off operation, or per function as we have in C. > > .text > blah blah blah > __INIT > lots of init stuff > __FINIT > more .text stuff > > Now, someone comes along and modifies this to be: > > .text > blah blah blah > .data > something else Yeah, that would be kind of careless; not putting .data above the .text, or at least closing with a .previous, but sure it could sneak past review. > __INIT > lots of init stuff > __FINIT The presence of the above 3 lines of init block (i.e. here or not) doesn't really change the fact that the .data guy broke the below .text code by grandfathering it into .data -- But you could argue that him seeing the 1st __INIT and that influenced him to decide to not read any further down into the file -- which probably does happen, though.... :( > more .text stuff > > Now, what is the effect of that __FINIT now? You get the following .text > emitted into the .data section instead. This is basically the same problem > you've just encounted. > > Maybe: > > __FINIT > .text > > is the safest solution - and __FINIT becomes just a no-op marker to avoid > anyone relying on its properties. That seems reasonable to me. I can't think of any self auditing that is reasonably simple to implement. One downside of __FINIT as a no-op vs. what it is today, is that a dangling __FINIT in a file with no other previous sections will emit a warning. But that is a small low value corner case I think. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
