From: Arnd Bergmann <[email protected]>
The newly added amd_check_microcode() function has two conflicting definitions
if CONFIG_CPU_SUP_AMD is enabled and CONFIG_MICROCODE_AMD is disabled. Since
the header with the stub definition is not included in cpu/amd.c, this only
causes a -Wmissing-prototype warning with W=1
arch/x86/kernel/cpu/amd.c:1289:6: error: no previous prototype for 'amd_check_microcode' [-Werror=missing-prototypes]
Adding the missing #include shows the other problem:
arch/x86/kernel/cpu/amd.c:1290:6: error: redefinition of 'amd_check_microcode'
arch/x86/include/asm/microcode_amd.h:58:20: note: previous definition of 'amd_check_microcode' with type 'void(void)'
Change the stub function to use the matching #ifdef check for the amd cpu
support instead of the microcode and include the header to avoid both and
make it behave consistently.
Fixes: 522b1d69219d8 ("x86/cpu/amd: Add a Zenbleed fix")
Signed-off-by: Arnd Bergmann <[email protected]>
---
arch/x86/include/asm/microcode_amd.h | 7 ++++++-
arch/x86/kernel/cpu/amd.c | 1 +
2 files changed, 7 insertions(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/microcode_amd.h b/arch/x86/include/asm/microcode_amd.h
index 9675c621c1ca4..6a860d40b0411 100644
--- a/arch/x86/include/asm/microcode_amd.h
+++ b/arch/x86/include/asm/microcode_amd.h
@@ -48,13 +48,18 @@ extern void __init load_ucode_amd_bsp(unsigned int family);
extern void load_ucode_amd_ap(unsigned int family);
extern int __init save_microcode_in_initrd_amd(unsigned int family);
void reload_ucode_amd(unsigned int cpu);
-extern void amd_check_microcode(void);
#else
static inline void __init load_ucode_amd_bsp(unsigned int family) {}
static inline void load_ucode_amd_ap(unsigned int family) {}
static inline int __init
save_microcode_in_initrd_amd(unsigned int family) { return -EINVAL; }
static inline void reload_ucode_amd(unsigned int cpu) {}
+#endif
+
+#ifdef CONFIG_CPU_SUP_AMD
+extern void amd_check_microcode(void);
+#else
static inline void amd_check_microcode(void) {}
#endif
+
#endif /* _ASM_X86_MICROCODE_AMD_H */
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 26ad7ca423e7c..24596e3c106b7 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -15,6 +15,7 @@
#include <asm/cpu.h>
#include <asm/spec-ctrl.h>
#include <asm/smp.h>
+#include <asm/microcode_amd.h>
#include <asm/numa.h>
#include <asm/pci-direct.h>
#include <asm/delay.h>
--
2.39.2
On Tue, Jul 25, 2023 at 10:26:13AM +0200, Arnd Bergmann wrote:
> From: Arnd Bergmann <[email protected]>
>
> The newly added amd_check_microcode() function has two conflicting definitions
> if CONFIG_CPU_SUP_AMD is enabled and CONFIG_MICROCODE_AMD is disabled. Since
> the header with the stub definition is not included in cpu/amd.c, this only
> causes a -Wmissing-prototype warning with W=1
Can we please promote -Wmissing-prototype to default or is it too noisy
yet?
> diff --git a/arch/x86/include/asm/microcode_amd.h b/arch/x86/include/asm/microcode_amd.h
> index 9675c621c1ca4..6a860d40b0411 100644
> --- a/arch/x86/include/asm/microcode_amd.h
> +++ b/arch/x86/include/asm/microcode_amd.h
> @@ -48,13 +48,18 @@ extern void __init load_ucode_amd_bsp(unsigned int family);
> extern void load_ucode_amd_ap(unsigned int family);
> extern int __init save_microcode_in_initrd_amd(unsigned int family);
> void reload_ucode_amd(unsigned int cpu);
> -extern void amd_check_microcode(void);
> #else
> static inline void __init load_ucode_amd_bsp(unsigned int family) {}
> static inline void load_ucode_amd_ap(unsigned int family) {}
> static inline int __init
> save_microcode_in_initrd_amd(unsigned int family) { return -EINVAL; }
> static inline void reload_ucode_amd(unsigned int cpu) {}
> +#endif
> +
> +#ifdef CONFIG_CPU_SUP_AMD
> +extern void amd_check_microcode(void);
> +#else
> static inline void amd_check_microcode(void) {}
> #endif
> +
> #endif /* _ASM_X86_MICROCODE_AMD_H */
Considering how cpu/amd.c provides the function implementation, that
header gunk should not be in microcode_amd.h but in ...asm/processor.h,
I'd say.
Thx.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
On Tue, Jul 25, 2023, at 11:20, Borislav Petkov wrote:
> On Tue, Jul 25, 2023 at 10:26:13AM +0200, Arnd Bergmann wrote:
>> From: Arnd Bergmann <[email protected]>
>>
>> The newly added amd_check_microcode() function has two conflicting definitions
>> if CONFIG_CPU_SUP_AMD is enabled and CONFIG_MICROCODE_AMD is disabled. Since
>> the header with the stub definition is not included in cpu/amd.c, this only
>> causes a -Wmissing-prototype warning with W=1
>
> Can we please promote -Wmissing-prototype to default or is it too noisy
> yet?
I'm working on it, currently missing just 15 patches (down from 70 in 6.3)
before all randconfigs on x86 and arm are clean.
>> diff --git a/arch/x86/include/asm/microcode_amd.h b/arch/x86/include/asm/microcode_amd.h
>> index 9675c621c1ca4..6a860d40b0411 100644
>> --- a/arch/x86/include/asm/microcode_amd.h
>> +++ b/arch/x86/include/asm/microcode_amd.h
>> +#ifdef CONFIG_CPU_SUP_AMD
>> +extern void amd_check_microcode(void);
>> +#else
>> static inline void amd_check_microcode(void) {}
>> #endif
>> +
>> #endif /* _ASM_X86_MICROCODE_AMD_H */
>
> Considering how cpu/amd.c provides the function implementation, that
> header gunk should not be in microcode_amd.h but in ...asm/processor.h,
> I'd say.
Ok, I'll send a v2 with that changed.
Arnd