2019-11-26 22:17:31

by Jules Irenge

Subject: [PATCH] cpu: microcode: Add comma to 0

Add "," after 0
Because memory for the struct is being cleared
and elements after "," are missing on purpose
as they are being cleared to

Recommended by Boris Petkov

Signed-off-by: Jules Irenge <[email protected]>
---
arch/x86/kernel/cpu/microcode/amd.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
index a0e52bd00ecc..04ee649f4acb 100644
--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -418,7 +418,7 @@ static int __apply_microcode_amd(struct microcode_amd *mc)
static bool
apply_microcode_early_amd(u32 cpuid_1_eax, void *ucode, size_t size, bool save_patch)
{
- struct cont_desc desc = { 0 };
+ struct cont_desc desc = { 0, };
u8 (*patch)[PATCH_MAX_SIZE];
struct microcode_amd *mc;
u32 rev, dummy, *new_rev;
--
2.23.0

2019-11-27 06:57:07

by Ingo Molnar

Subject: Re: [PATCH] cpu: microcode: Add comma to 0

* Jules Irenge <[email protected]> wrote:

> Add "," after 0
> Because memory for the struct is being cleared
> and elements after "," are missing on purpose
> as they are being cleared to
>
> Recommended by Boris Petkov
>
> Signed-off-by: Jules Irenge <[email protected]>
> ---
> arch/x86/kernel/cpu/microcode/amd.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
> index a0e52bd00ecc..04ee649f4acb 100644
> --- a/arch/x86/kernel/cpu/microcode/amd.c
> +++ b/arch/x86/kernel/cpu/microcode/amd.c
> @@ -418,7 +418,7 @@ static int __apply_microcode_amd(struct microcode_amd *mc)
> static bool
> apply_microcode_early_amd(u32 cpuid_1_eax, void *ucode, size_t size, bool save_patch)
> {
> - struct cont_desc desc = { 0 };
> + struct cont_desc desc = { 0, };

This is 100% unnecessary - " = { }" is enough of a structure initializer.

Thanks,

Ingo

2019-11-27 11:28:31

by Borislav Petkov

Subject: Re: [PATCH] cpu: microcode: Add comma to 0

On Wed, Nov 27, 2019 at 07:54:36AM +0100, Ingo Molnar wrote:
>
> * Jules Irenge <[email protected]> wrote:
>
> > Add "," after 0
> > Because memory for the struct is being cleared
> > and elements after "," are missing on purpose
> > as they are being cleared to
> >
> > Recommended by Boris Petkov
> >
> > Signed-off-by: Jules Irenge <[email protected]>
> > ---
> > arch/x86/kernel/cpu/microcode/amd.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
> > index a0e52bd00ecc..04ee649f4acb 100644
> > --- a/arch/x86/kernel/cpu/microcode/amd.c
> > +++ b/arch/x86/kernel/cpu/microcode/amd.c
> > @@ -418,7 +418,7 @@ static int __apply_microcode_amd(struct microcode_amd *mc)
> > static bool
> > apply_microcode_early_amd(u32 cpuid_1_eax, void *ucode, size_t size, bool save_patch)
> > {
> > - struct cont_desc desc = { 0 };
> > + struct cont_desc desc = { 0, };
>
> This is 100% unnecessary - " = { }" is enough of a structure initializer.

That was my initial thought but empty initializers are not ISO C
compliant, I've been told.

--
Regards/Gruss,
Boris.

https://people.kernel.org/tglx/notes-about-netiquette

2019-11-27 16:51:54

by Ingo Molnar

Subject: Re: [PATCH] cpu: microcode: Add comma to 0

* Borislav Petkov <[email protected]> wrote:

> On Wed, Nov 27, 2019 at 07:54:36AM +0100, Ingo Molnar wrote:
> >
> > * Jules Irenge <[email protected]> wrote:
> >
> > > Add "," after 0
> > > Because memory for the struct is being cleared
> > > and elements after "," are missing on purpose
> > > as they are being cleared to
> > >
> > > Recommended by Boris Petkov
> > >
> > > Signed-off-by: Jules Irenge <[email protected]>
> > > ---
> > > arch/x86/kernel/cpu/microcode/amd.c | 2 +-
> > > 1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
> > > index a0e52bd00ecc..04ee649f4acb 100644
> > > --- a/arch/x86/kernel/cpu/microcode/amd.c
> > > +++ b/arch/x86/kernel/cpu/microcode/amd.c
> > > @@ -418,7 +418,7 @@ static int __apply_microcode_amd(struct microcode_amd *mc)
> > > static bool
> > > apply_microcode_early_amd(u32 cpuid_1_eax, void *ucode, size_t size, bool save_patch)
> > > {
> > > - struct cont_desc desc = { 0 };
> > > + struct cont_desc desc = { 0, };
> >
> > This is 100% unnecessary - " = { }" is enough of a structure initializer.
>
> That was my initial thought but empty initializers are not ISO C
> compliant, I've been told.

Yeah, but the kernel isn't ISO C, and the hive mind has spoken in favor
of the shortest variant:

dagon:~/tip> git grep '= { }' | wc -l
647

dagon:~/tip> git grep '= { 0, }' | wc -l
231

dagon:~/tip> git grep '= { NULL, }' | wc -l
38

:-)

Thanks,

Ingo

2019-11-27 17:17:03

by Borislav Petkov

Subject: Re: [PATCH] cpu: microcode: Add comma to 0

On Wed, Nov 27, 2019 at 05:50:25PM +0100, Ingo Molnar wrote:
> Yeah, but the kernel isn't ISO C, and the hive mind has spoken in favor
> of the shortest variant:
>
> dagon:~/tip> git grep '= { }' | wc -l
> 647
>
> dagon:~/tip> git grep '= { 0, }' | wc -l
> 231
>
> dagon:~/tip> git grep '= { NULL, }' | wc -l
> 38
>
> :-)

Ok then, keeping it as is.

--
Regards/Gruss,
Boris.

https://people.kernel.org/tglx/notes-about-netiquette