Messages in this thread | | | Date | Tue, 23 Mar 2021 15:52:37 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH] module: treat exit sections the same as init sections when !CONFIG_MODULE_UNLOAD |
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On Tue, Mar 23, 2021 at 03:27:56PM +0100, Jessica Yu wrote: > Dynamic code patching (alternatives, jump_label and static_call) can > have sites in __exit code, even if __exit is never executed. Therefore > __exit must be present at runtime, at least for as long as __init code > is. > > Additionally, for jump_label and static_call, the __exit sites must also > identify as within_module_init(), such that the infrastructure is aware > to never touch them after module init -- alternatives are only ran once > at init and hence don't have this particular constraint. > > By making __exit identify as __init for !MODULE_UNLOAD, the above is > satisfied. > > So the section ordering should look like the following when > !CONFIG_MODULE_UNLOAD, with the .exit sections moved to the init region of > the module. > > Core section allocation order: > .text > .rodata > __ksymtab_gpl > __ksymtab_strings > .note.* sections > .bss > .data > .gnu.linkonce.this_module > Init section allocation order: > .init.text > .exit.text > .symtab > .strtab > > [jeyu: thanks to Peter Zijlstra for most of the changelog] > > Link: https://lore.kernel.org/lkml/YFiuphGw0RKehWsQ@gunter/ > Signed-off-by: Jessica Yu <jeyu@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> --- > > Do you want to take this patch with the other static_call patches? Or > should I take this through modules-next?
Take it through modules-next, I haven't seen an actual report on this and it's been broken forever afaict. I only found it by accident while chasing this other problem.
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