2023-10-10 08:55:15

by Huacai Chen

[permalink] [raw]
Subject: [PATCH] MIPS: KVM: Fix a build warning about variable set but not used

After commit 411740f5422a ("KVM: MIPS/MMU: Implement KVM_CAP_SYNC_MMU")
old_pte is no longer used in kvm_mips_map_page(). So remove it to fix a
build warning about variable set but not used:

arch/mips/kvm/mmu.c: In function 'kvm_mips_map_page':
>> arch/mips/kvm/mmu.c:701:29: warning: variable 'old_pte' set but not used [-Wunused-but-set-variable]
701 | pte_t *ptep, entry, old_pte;
| ^~~~~~~

Cc: [email protected]
Fixes: 411740f5422a960 ("KVM: MIPS/MMU: Implement KVM_CAP_SYNC_MMU")
Reported-by: kernel test robot <[email protected]>
Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
Signed-off-by: Huacai Chen <[email protected]>
---
arch/mips/kvm/mmu.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/mips/kvm/mmu.c b/arch/mips/kvm/mmu.c
index e8c08988ed37..cc09fd23aae3 100644
--- a/arch/mips/kvm/mmu.c
+++ b/arch/mips/kvm/mmu.c
@@ -592,7 +592,7 @@ static int kvm_mips_map_page(struct kvm_vcpu *vcpu, unsigned long gpa,
gfn_t gfn = gpa >> PAGE_SHIFT;
int srcu_idx, err;
kvm_pfn_t pfn;
- pte_t *ptep, entry, old_pte;
+ pte_t *ptep, entry;
bool writeable;
unsigned long prot_bits;
unsigned long mmu_seq;
@@ -664,7 +664,6 @@ static int kvm_mips_map_page(struct kvm_vcpu *vcpu, unsigned long gpa,
entry = pfn_pte(pfn, __pgprot(prot_bits));

/* Write the PTE */
- old_pte = *ptep;
set_pte(ptep, entry);

err = 0;
--
2.39.3


2023-10-10 14:00:30

by Philippe Mathieu-Daudé

[permalink] [raw]
Subject: Re: [PATCH] MIPS: KVM: Fix a build warning about variable set but not used

On 10/10/23 10:54, Huacai Chen wrote:
> After commit 411740f5422a ("KVM: MIPS/MMU: Implement KVM_CAP_SYNC_MMU")

Date: Tue Dec 13 16:32:39 2016 +0000

7 years ago...

Reviewed-by: Philippe Mathieu-Daudé <[email protected]>

> old_pte is no longer used in kvm_mips_map_page(). So remove it to fix a
> build warning about variable set but not used:
>
> arch/mips/kvm/mmu.c: In function 'kvm_mips_map_page':
>>> arch/mips/kvm/mmu.c:701:29: warning: variable 'old_pte' set but not used [-Wunused-but-set-variable]
> 701 | pte_t *ptep, entry, old_pte;
> | ^~~~~~~
>
> Cc: [email protected]
> Fixes: 411740f5422a960 ("KVM: MIPS/MMU: Implement KVM_CAP_SYNC_MMU")
> Reported-by: kernel test robot <[email protected]>
> Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
> Signed-off-by: Huacai Chen <[email protected]>
> ---
> arch/mips/kvm/mmu.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)

2023-10-19 08:52:51

by Thomas Bogendoerfer

[permalink] [raw]
Subject: Re: [PATCH] MIPS: KVM: Fix a build warning about variable set but not used

On Tue, Oct 10, 2023 at 04:54:34PM +0800, Huacai Chen wrote:
> After commit 411740f5422a ("KVM: MIPS/MMU: Implement KVM_CAP_SYNC_MMU")
> old_pte is no longer used in kvm_mips_map_page(). So remove it to fix a
> build warning about variable set but not used:
>
> arch/mips/kvm/mmu.c: In function 'kvm_mips_map_page':
> >> arch/mips/kvm/mmu.c:701:29: warning: variable 'old_pte' set but not used [-Wunused-but-set-variable]
> 701 | pte_t *ptep, entry, old_pte;
> | ^~~~~~~
>
> Cc: [email protected]
> Fixes: 411740f5422a960 ("KVM: MIPS/MMU: Implement KVM_CAP_SYNC_MMU")
> Reported-by: kernel test robot <[email protected]>
> Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
> Signed-off-by: Huacai Chen <[email protected]>
> ---
> arch/mips/kvm/mmu.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/arch/mips/kvm/mmu.c b/arch/mips/kvm/mmu.c
> index e8c08988ed37..cc09fd23aae3 100644
> --- a/arch/mips/kvm/mmu.c
> +++ b/arch/mips/kvm/mmu.c
> @@ -592,7 +592,7 @@ static int kvm_mips_map_page(struct kvm_vcpu *vcpu, unsigned long gpa,
> gfn_t gfn = gpa >> PAGE_SHIFT;
> int srcu_idx, err;
> kvm_pfn_t pfn;
> - pte_t *ptep, entry, old_pte;
> + pte_t *ptep, entry;
> bool writeable;
> unsigned long prot_bits;
> unsigned long mmu_seq;
> @@ -664,7 +664,6 @@ static int kvm_mips_map_page(struct kvm_vcpu *vcpu, unsigned long gpa,
> entry = pfn_pte(pfn, __pgprot(prot_bits));
>
> /* Write the PTE */
> - old_pte = *ptep;
> set_pte(ptep, entry);
>
> err = 0;
> --
> 2.39.3

applied to mips-next.

Thomas.

--
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea. [ RFC1925, 2.3 ]