Certain warnings are emitted for powerpc code when building with a gcc-10
toolset:
WARNING: modpost: vmlinux.o(.text.unlikely+0x377c): Section mismatch in
reference from the function remove_pmd_table() to the function
.meminit.text:split_kernel_mapping()
The function remove_pmd_table() references
the function __meminit split_kernel_mapping().
This is often because remove_pmd_table lacks a __meminit
annotation or the annotation of split_kernel_mapping is wrong.
Add the appropriate __init and __meminit annotations to make modpost not
complain. In all the cases there are just a single callsite from another
__init or __meminit function:
__meminit remove_pagetable() -> remove_pud_table() -> remove_pmd_table()
__init prom_init() -> setup_secure_guest()
__init xive_spapr_init() -> xive_spapr_disabled()
Signed-off-by: Vladis Dronov <[email protected]>
---
arch/powerpc/kernel/prom_init.c | 4 ++--
arch/powerpc/mm/book3s64/radix_pgtable.c | 4 ++--
arch/powerpc/sysdev/xive/spapr.c | 2 +-
3 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index 90c604d00b7d..f6ca7f450361 100644
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -3262,7 +3262,7 @@ static int enter_secure_mode(unsigned long kbase, unsigned long fdt)
/*
* Call the Ultravisor to transfer us to secure memory if we have an ESM blob.
*/
-static void setup_secure_guest(unsigned long kbase, unsigned long fdt)
+static void __init setup_secure_guest(unsigned long kbase, unsigned long fdt)
{
int ret;
@@ -3292,7 +3292,7 @@ static void setup_secure_guest(unsigned long kbase, unsigned long fdt)
}
}
#else
-static void setup_secure_guest(unsigned long kbase, unsigned long fdt)
+static void __init setup_secure_guest(unsigned long kbase, unsigned long fdt)
{
}
#endif /* CONFIG_PPC_SVM */
diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c
index bb00e0cba119..b868c07110e3 100644
--- a/arch/powerpc/mm/book3s64/radix_pgtable.c
+++ b/arch/powerpc/mm/book3s64/radix_pgtable.c
@@ -800,7 +800,7 @@ static void __meminit split_kernel_mapping(unsigned long addr, unsigned long end
pte_clear(&init_mm, addr, pte);
}
-static void remove_pmd_table(pmd_t *pmd_start, unsigned long addr,
+static void __meminit remove_pmd_table(pmd_t *pmd_start, unsigned long addr,
unsigned long end)
{
unsigned long next;
@@ -825,7 +825,7 @@ static void remove_pmd_table(pmd_t *pmd_start, unsigned long addr,
}
}
-static void remove_pud_table(pud_t *pud_start, unsigned long addr,
+static void __meminit remove_pud_table(pud_t *pud_start, unsigned long addr,
unsigned long end)
{
unsigned long next;
diff --git a/arch/powerpc/sysdev/xive/spapr.c b/arch/powerpc/sysdev/xive/spapr.c
index f0551a2be9df..1e3674d7ea7b 100644
--- a/arch/powerpc/sysdev/xive/spapr.c
+++ b/arch/powerpc/sysdev/xive/spapr.c
@@ -768,7 +768,7 @@ static const u8 *get_vec5_feature(unsigned int index)
return vec5 + index;
}
-static bool xive_spapr_disabled(void)
+static bool __init xive_spapr_disabled(void)
{
const u8 *vec5_xive;
--
2.26.2
On Wed, Jul 29, 2020 at 03:37:41PM +0200, Vladis Dronov wrote:
> Certain warnings are emitted for powerpc code when building with a gcc-10
> toolset:
>
> WARNING: modpost: vmlinux.o(.text.unlikely+0x377c): Section mismatch in
> reference from the function remove_pmd_table() to the function
> .meminit.text:split_kernel_mapping()
> The function remove_pmd_table() references
> the function __meminit split_kernel_mapping().
> This is often because remove_pmd_table lacks a __meminit
> annotation or the annotation of split_kernel_mapping is wrong.
>
> Add the appropriate __init and __meminit annotations to make modpost not
> complain. In all the cases there are just a single callsite from another
> __init or __meminit function:
>
> __meminit remove_pagetable() -> remove_pud_table() -> remove_pmd_table()
> __init prom_init() -> setup_secure_guest()
> __init xive_spapr_init() -> xive_spapr_disabled()
So what changed? These functions were inlined with older compilers, but
not anymore?
Segher
Hello,
----- Original Message -----
> From: "Segher Boessenkool" <[email protected]>
> To: "Vladis Dronov" <[email protected]>
> Cc: [email protected], "Aneesh Kumar K . V" <[email protected]>, [email protected],
> "Paul Mackerras" <[email protected]>
> Sent: Wednesday, July 29, 2020 4:49:49 PM
> Subject: Re: [PATCH] powerpc: fix function annotations to avoid section mismatch warnings with gcc-10
>
> On Wed, Jul 29, 2020 at 03:37:41PM +0200, Vladis Dronov wrote:
> > Certain warnings are emitted for powerpc code when building with a gcc-10
> > toolset:
> >
> > WARNING: modpost: vmlinux.o(.text.unlikely+0x377c): Section mismatch in
> > reference from the function remove_pmd_table() to the function
> > .meminit.text:split_kernel_mapping()
> > The function remove_pmd_table() references
> > the function __meminit split_kernel_mapping().
> > This is often because remove_pmd_table lacks a __meminit
> > annotation or the annotation of split_kernel_mapping is wrong.
> >
> > Add the appropriate __init and __meminit annotations to make modpost not
> > complain. In all the cases there are just a single callsite from another
> > __init or __meminit function:
> >
> > __meminit remove_pagetable() -> remove_pud_table() -> remove_pmd_table()
> > __init prom_init() -> setup_secure_guest()
> > __init xive_spapr_init() -> xive_spapr_disabled()
>
> So what changed? These functions were inlined with older compilers, but
> not anymore?
Yes, exactly. Gcc-10 does not inline them anymore. If this is because of my
build system, this can happen to others also.
The same thing was fixed by Linus in e99332e7b4cd ("gcc-10: mark more functions
__init to avoid section mismatch warnings").
>
> Segher
Best regards,
Vladis Dronov | Red Hat, Inc. | The Core Kernel | Senior Software Engineer
On Wed, Jul 29, 2020 at 03:44:56PM -0400, Vladis Dronov wrote:
> > > Certain warnings are emitted for powerpc code when building with a gcc-10
> > > toolset:
> > >
> > > WARNING: modpost: vmlinux.o(.text.unlikely+0x377c): Section mismatch in
> > > reference from the function remove_pmd_table() to the function
> > > .meminit.text:split_kernel_mapping()
> > > The function remove_pmd_table() references
> > > the function __meminit split_kernel_mapping().
> > > This is often because remove_pmd_table lacks a __meminit
> > > annotation or the annotation of split_kernel_mapping is wrong.
> > >
> > > Add the appropriate __init and __meminit annotations to make modpost not
> > > complain. In all the cases there are just a single callsite from another
> > > __init or __meminit function:
> > >
> > > __meminit remove_pagetable() -> remove_pud_table() -> remove_pmd_table()
> > > __init prom_init() -> setup_secure_guest()
> > > __init xive_spapr_init() -> xive_spapr_disabled()
> >
> > So what changed? These functions were inlined with older compilers, but
> > not anymore?
>
> Yes, exactly. Gcc-10 does not inline them anymore. If this is because of my
> build system, this can happen to others also.
>
> The same thing was fixed by Linus in e99332e7b4cd ("gcc-10: mark more functions
> __init to avoid section mismatch warnings").
It sounds like this is part of "-finline-functions was retuned" on
<https://gcc.gnu.org/gcc-10/changes.html>? So everyone should see it
(no matter what config or build system), and it is a good thing too :-)
Thanks for the confirmation,
Segher
Segher Boessenkool <[email protected]> writes:
> On Wed, Jul 29, 2020 at 03:44:56PM -0400, Vladis Dronov wrote:
>> > > Certain warnings are emitted for powerpc code when building with a gcc-10
>> > > toolset:
>> > >
>> > > WARNING: modpost: vmlinux.o(.text.unlikely+0x377c): Section mismatch in
>> > > reference from the function remove_pmd_table() to the function
>> > > .meminit.text:split_kernel_mapping()
>> > > The function remove_pmd_table() references
>> > > the function __meminit split_kernel_mapping().
>> > > This is often because remove_pmd_table lacks a __meminit
>> > > annotation or the annotation of split_kernel_mapping is wrong.
>> > >
>> > > Add the appropriate __init and __meminit annotations to make modpost not
>> > > complain. In all the cases there are just a single callsite from another
>> > > __init or __meminit function:
>> > >
>> > > __meminit remove_pagetable() -> remove_pud_table() -> remove_pmd_table()
>> > > __init prom_init() -> setup_secure_guest()
>> > > __init xive_spapr_init() -> xive_spapr_disabled()
>> >
>> > So what changed? These functions were inlined with older compilers, but
>> > not anymore?
>>
>> Yes, exactly. Gcc-10 does not inline them anymore. If this is because of my
>> build system, this can happen to others also.
>>
>> The same thing was fixed by Linus in e99332e7b4cd ("gcc-10: mark more functions
>> __init to avoid section mismatch warnings").
>
> It sounds like this is part of "-finline-functions was retuned" on
> <https://gcc.gnu.org/gcc-10/changes.html>? So everyone should see it
> (no matter what config or build system), and it is a good thing too :-)
I haven't seen it in my GCC 10 builds, so there must be some other
subtlety. Probably it depends on details of the .config.
cheers
Hello, Michael,
----- Original Message -----
> From: "Michael Ellerman" <[email protected]>
> Subject: Re: [PATCH] powerpc: fix function annotations to avoid section mismatch warnings with gcc-10
>
...
> >> > So what changed? These functions were inlined with older compilers, but
> >> > not anymore?
> >>
> >> Yes, exactly. Gcc-10 does not inline them anymore. If this is because of
> >> my
> >> build system, this can happen to others also.
> >>
> >> The same thing was fixed by Linus in e99332e7b4cd ("gcc-10: mark more
> >> functions
> >> __init to avoid section mismatch warnings").
> >
> > It sounds like this is part of "-finline-functions was retuned" on
> > <https://gcc.gnu.org/gcc-10/changes.html>? So everyone should see it
> > (no matter what config or build system), and it is a good thing too :-)
>
> I haven't seen it in my GCC 10 builds, so there must be some other
> subtlety. Probably it depends on details of the .config.
>
I've just had this building the latest upstream for the ppc64le with a derivative
of the RHEL-8 config. This can probably be a compiler/linker setting, like -O2
versus -O3.
> cheers
Best regards,
Vladis Dronov | Red Hat, Inc. | The Core Kernel | Senior Software Engineer
On Wed, 29 Jul 2020 15:37:41 +0200, Vladis Dronov wrote:
> Certain warnings are emitted for powerpc code when building with a gcc-10
> toolset:
>
> WARNING: modpost: vmlinux.o(.text.unlikely+0x377c): Section mismatch in
> reference from the function remove_pmd_table() to the function
> .meminit.text:split_kernel_mapping()
> The function remove_pmd_table() references
> the function __meminit split_kernel_mapping().
> This is often because remove_pmd_table lacks a __meminit
> annotation or the annotation of split_kernel_mapping is wrong.
>
> [...]
Applied to powerpc/next.
[1/1] powerpc: fix function annotations to avoid section mismatch warnings with gcc-10
https://git.kernel.org/powerpc/c/aff779515a070df7e23da9e86f1096f7d10d647e
cheers