2020-05-08 08:07:19

by Stephen Rothwell

[permalink] [raw]
Subject: linux-next: manual merge of the livepatching tree with the modules tree

Hi all,

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.

I fixed it up (see below) and can carry the fix as necessary. This
is now fixed as far as linux-next is concerned, but any non trivial
conflicts should be mentioned to your upstream maintainer when your tree
is submitted for merging. You may also want to consider cooperating
with the maintainer of the conflicting tree to minimise any particularly
complex conflicts.

--
Cheers,
Stephen Rothwell

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
/*


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2020-05-11 11:46:15

by Miroslav Benes

[permalink] [raw]
Subject: Re: linux-next: manual merge of the livepatching tree with the modules tree

On Fri, 8 May 2020, Stephen Rothwell wrote:

> Hi all,
>
> 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.
>
> I fixed it up (see below) and can carry the fix as necessary. This
> is now fixed as far as linux-next is concerned, but any non trivial
> conflicts should be mentioned to your upstream maintainer when your tree
> is submitted for merging. You may also want to consider cooperating
> with the maintainer of the conflicting tree to minimise any particularly
> complex conflicts.
>
> --
> Cheers,
> Stephen Rothwell
>
> 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 */

The line should go away too as part of the final conflict resolution, but
we'll have to deal with that later while sending pull requests.

Otherwise it looks good.

Thanks
Miroslav

> 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
> /*
>

2020-06-05 04:48:18

by Stephen Rothwell

[permalink] [raw]
Subject: Re: linux-next: manual merge of the livepatching tree with the modules tree

Hi all,

On Fri, 8 May 2020 18:05:24 +1000 Stephen Rothwell <[email protected]> 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.

--
Cheers,
Stephen Rothwell


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2020-06-05 07:00:38

by Jiri Kosina

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

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

2020-06-05 07:41:38

by Jessica Yu

[permalink] [raw]
Subject: Re: linux-next: manual merge of the livepatching tree with the modules tree

+++ Jiri Kosina [05/06/20 08:56 +0200]:
>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.

Yep, will do. Thanks!