Re: [PATCH] powerpc: fix function annotations to avoid section mismatch warnings with gcc-10
Hello, Michael,
- Original Message -
> From: "Michael Ellerman"
> 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
Re: [PATCH] powerpc: fix function annotations to avoid section mismatch warnings with gcc-10
Hello,
- Original Message -
> From: "Segher Boessenkool"
> To: "Vladis Dronov"
> Cc: linuxppc-dev@lists.ozlabs.org, "Aneesh Kumar K . V"
> , linux-ker...@vger.kernel.org,
> "Paul Mackerras"
> 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
[PATCH] powerpc: fix function annotations to avoid section mismatch warnings with gcc-10
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
---
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(_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
