Messages in this thread |  | | | Date | Sun, 26 Apr 2009 11:09:06 +0200 | | From | Sam Ravnborg <> | | Subject | Re: [PATCH v3 1/3] Make section names compatible with -ffunction-sections -fdata-sections |
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On Sat, Apr 25, 2009 at 10:10:38PM -0400, Tim Abbott wrote: > On Fri, 24 Apr 2009, Sam Ravnborg wrote: > > > This patch touches far too many files. > > We should try to work out a method so we are in better control > > of the section names, so renaming in the end is a simple patch > > touching only a few files. > > OK, I'm now planning to implement this approach. > > > > -.section .text.head, "ax" > > > +.section .text..head, "ax" > > > > Use __HEAD (from include/linux/init.h) > > Same goes for all other uses of .text.head. > > I notice that __HEAD uses .head.text, while some architectures use > .text.head. It looks like this is just an inconsistency across > architectures that will be removed as a consequence of this cleanup work > (no architecture uses both .head.text and .text.head). Correct - this is implied by the introduction of __HEAD. For users of the old naming schme (like i386) you need to adjust the linker script too.
> One challenge with this approach is that many linker scripts use these > section names in more complex ways than just squashing HEAD_TEXT at the > start of the text section. For example, the the linker scripts for x86 > and ia64 have code like: > > .text.head : AT(ADDR(.text.head) - LOAD_OFFSET) { > _text = .; /* Text and read-only data */ > *(.text.head) > } :text = 0x9090 > > which can't user either the __HEAD macro (which is the full .section line) > or the HEAD_TEXT macro (which is the *(.head.text)).
The simple way to deal wi8th this is to accept some duplication of naming in order to keep readability. So I suggest you to use:
.head.text : AT(ADDR(.head.text) - LOAD_OFFSET) { _text = .; /* Text and read-only data */ HEAD_TEXT } :text = 0x9090 We need to be carefull about keeping some sort of readability of these linker macro files.
I was not specific in my last mail about this - but I assume you have understood that the naming ".head.text" was selected so it is compatible wiht -ffunction-sections. In other words no need for any ugly ".." here.
We should try to be as consistent as possible across architectures here so it is better to toach a few additiona files rather than adding macros and the like to accept there sub-optimal section naming.
Sam
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