Re: [RFC] move __devinit or __init printk constant format stringsto __devinitconst or __initdata?

From: David Daney
Date: Tue Jul 21 2009 - 19:51:26 EST


Joe Perches wrote:
On Tue, 2009-07-21 at 17:57 -0500, Matt Mackall wrote:
On Tue, 2009-07-21 at 14:56 -0700, Joe Perches wrote:
On Tue, 2009-07-21 at 16:48 -0500, Matt Mackall wrote:
On Tue, 2009-07-21 at 14:20 -0700, Joe Perches wrote:
Is moving constant string formats to __devinitconst or __initdata
useful for embedded environments?
Interesting notion, but not worth the trouble in my mind. I think it's
more worthwhile to look into automatic such stuff in the build somehow.
I think it's not possible today to get gcc to mark
the format strings without source modification.
Yep, that's why I specifically said 'build'. It can probably be done in
a post-processing step with some ELF wizardry.

Know any elven wizards?


It would be tricky, the string data from the entire compilation unit is intermingled. You would have to separate out only those strings referenced from __init sections into their own section and fix up all symbols and relocations that were affected.

Probably easier would be to use the plug-in feature that will be part of GCC-4.5 (or will that be called GCC-5.0??), and create a special Linux kernel GCC plug-in that just emits the __init literal strings to the proper section to begin with. This wouldn't be unprecedented, the Mozilla people already use their own extensions to GCC, and will probably migrate to GCC plug-ins. We don't want the kernel to get left behind in the GCC plug-in race.

David Daney
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