[Re: [PATCH] ARM: move body of head-common.S back to text section] On 03/07/2013 (Wed 18:20) Russell King - ARM Linux wrote: > On Wed, Jul 03, 2013 at 11:30:12AM -0400, Paul Gortmaker wrote: > > [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. > > I read the info pages, because I thought it was a pop operation too. > I was concerned that .section didn't push the previous section onto the > stack. > > However, .popsection is the pseudio-op which pops. .previous just toggles > the current section with the section immediately before it. > > So: > > .text > .data > .previous > /* this is .text */ > .previous > /* this is .data */ > .previous > /* this is .text */ > .previous > /* this is .data */ Cool -- I bet we weren't the only ones thinking it was a pop. Thanks. Does that make __FINIT less evil than we previously assumed? I think your example was the following pseudo-patch: .text <some text> + .data + <some data> __INIT <big hunk of init> __FINIT /* this below used to be text */ <more stuff that was originally meant for text> Even if it is a toggle (vs. pop), the end text will now become data, so the no-op __FINIT with an explicit section called out just below it may still be the most unambiguous way to indicate what is going on. > > > 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. > > That warning from __FINIT will only happen if there has been no section > or .text or .data statement in the file at all. As soon as you have any > statement setting any kind of section, .previous doesn't warn. > > So: > > .text > ... > __FINIT > > produces no warning.o Yep -- we are both saying the same thing here - hence why I called it a small low value corner case. -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
