Messages in this thread | | | Date | Thu, 10 Sep 2020 08:07:04 -0700 | From | Sami Tolvanen <> | Subject | Re: [PATCH v2 15/28] init: lto: ensure initcall ordering |
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On Thu, Sep 10, 2020 at 10:25:40AM +0100, David Woodhouse wrote: > On Thu, 2020-09-03 at 13:30 -0700, Sami Tolvanen wrote: > > With LTO, the compiler doesn't necessarily obey the link order for > > initcalls, and initcall variables need globally unique names to avoid > > collisions at link time. > > > > This change exports __KBUILD_MODNAME and adds the initcall_id() macro, > > which uses it together with __COUNTER__ and __LINE__ to help ensure > > these variables have unique names, and moves each variable to its own > > section when LTO is enabled, so the correct order can be specified using > > a linker script. > > > > The generate_initcall_ordering.pl script uses nm to find initcalls from > > the object files passed to the linker, and generates a linker script > > that specifies the intended order. With LTO, the script is called in > > link-vmlinux.sh. > > Is this guaranteed to give you the *same* initcall ordering with LTO as > without?
Yes. It follows the link order, just like the linker without LTO, and also preserves the order within each file.
Sami
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