Re: linux-next: manual merge of the livepatching tree with the modules tree

From: Jiri Kosina
Date: Fri Jun 05 2020 - 02:56:20 EST


On Fri, 5 Jun 2020, Stephen Rothwell wrote:

> > Today's linux-next merge of the livepatching tree got a conflict in:
> >
> > kernel/module.c
> >
> > between commits:
> >
> > db991af02f11 ("module: break nested ARCH_HAS_STRICT_MODULE_RWX and STRICT_MODULE_RWX #ifdefs")
> > 5c3a7db0c7ec ("module: Harden STRICT_MODULE_RWX")
> >
> > from the modules tree and commit:
> >
> > e6eff4376e28 ("module: Make module_enable_ro() static again")
> >
> > from the livepatching tree.
> >
> > diff --cc kernel/module.c
> > index c69291362676,a26343ea4d50..000000000000
> > --- a/kernel/module.c
> > +++ b/kernel/module.c
> > @@@ -2055,29 -2023,20 +2042,30 @@@ static void module_enable_nx(const stru
> > frob_writable_data(&mod->init_layout, set_memory_nx);
> > }
> >
> > +static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
> > + char *secstrings, struct module *mod)
> > +{
> > + const unsigned long shf_wx = SHF_WRITE|SHF_EXECINSTR;
> > + int i;
> > +
> > + for (i = 0; i < hdr->e_shnum; i++) {
> > + if ((sechdrs[i].sh_flags & shf_wx) == shf_wx)
> > + return -ENOEXEC;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > #else /* !CONFIG_STRICT_MODULE_RWX */
> > +/* module_{enable,disable}_ro() stubs are in module.h */
> > static void module_enable_nx(const struct module *mod) { }
> > + static void module_enable_ro(const struct module *mod, bool after_init) {}
> > -#endif /* CONFIG_STRICT_MODULE_RWX */
> > -static void module_enable_x(const struct module *mod)
> > +static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
> > + char *secstrings, struct module *mod)
> > {
> > - frob_text(&mod->core_layout, set_memory_x);
> > - frob_text(&mod->init_layout, set_memory_x);
> > + return 0;
> > }
> > -#else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
> > -static void module_enable_nx(const struct module *mod) { }
> > -static void module_enable_x(const struct module *mod) { }
> > -#endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
> > -
> > +#endif /* CONFIG_STRICT_MODULE_RWX */
> >
> > #ifdef CONFIG_LIVEPATCH
> > /*
>
> This is now a conflict between the modules tree and Linus' tree.

I've made Linus aware of this coming when sending livepatching tree, but
given the fact that the modules tree hasn't been merged yet, Jessica, I
believe it'd make sense to point it out again once sending your tree.

Thanks,

--
Jiri Kosina
SUSE Labs