[PATCH v2] KVM: SVM: Fix "error" isn't initialized

[PATCH v2] KVM: SVM: Fix "error" isn't initialized

[Haiwei Li]

 From e7f9c786e43ef4f890b8a01f15f8f00786f4b14a Mon Sep 17 00:00:00 2001
From: Haiwei Li <lihaiwei@tencent.com>
Date: Wed, 27 Nov 2019 15:00:49 +0800
Subject: [PATCH v2] fix: 'error' is not initialized

There are a bunch of error paths were "error" isn't initialized.

Signed-off-by: Haiwei Li <lihaiwei@tencent.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
---
  arch/x86/kvm/svm.c           | 3 ++-
  drivers/crypto/ccp/psp-dev.c | 2 ++
  2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 362e874..9eef6fc 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -6308,7 +6308,8 @@ static int sev_flush_asids(void)
  	up_write(&sev_deactivate_lock);

  	if (ret)
-		pr_err("SEV: DF_FLUSH failed, ret=%d, error=%#x\n", ret, error);
+		pr_err("SEV: DF_FLUSH failed, ret=%d. PSP returned error=%#x\n",
+		       ret, error);

  	return ret;
  }
diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c
index 39fdd06..c486c24 100644
--- a/drivers/crypto/ccp/psp-dev.c
+++ b/drivers/crypto/ccp/psp-dev.c
@@ -155,6 +155,8 @@ static int __sev_do_cmd_locked(int cmd, void *data, 
int *psp_ret)
  	unsigned int phys_lsb, phys_msb;
  	unsigned int reg, ret = 0;

+	*psp_ret = -1;
+
  	if (!psp)
  		return -ENODEV;

--
1.8.3.1

Re: [PATCH v2] KVM: SVM: Fix "error" isn't initialized

[Christophe de Dinechin]

> On 27 Nov 2019, at 08:23, Haiwei Li <lihaiwei.kernel@gmail.com> wrote:
> 
> From e7f9c786e43ef4f890b8a01f15f8f00786f4b14a Mon Sep 17 00:00:00 2001
> From: Haiwei Li <lihaiwei@tencent.com>
> Date: Wed, 27 Nov 2019 15:00:49 +0800
> Subject: [PATCH v2] fix: 'error' is not initialized
> 
> There are a bunch of error paths were "error" isn't initialized.
> 
> Signed-off-by: Haiwei Li <lihaiwei@tencent.com>
> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
> arch/x86/kvm/svm.c           | 3 ++-
> drivers/crypto/ccp/psp-dev.c | 2 ++
> 2 files changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
> index 362e874..9eef6fc 100644
> --- a/arch/x86/kvm/svm.c
> +++ b/arch/x86/kvm/svm.c
> @@ -6308,7 +6308,8 @@ static int sev_flush_asids(void)
> 	up_write(&sev_deactivate_lock);
> 
> 	if (ret)
> -		pr_err("SEV: DF_FLUSH failed, ret=%d, error=%#x\n", ret, error);
> +		pr_err("SEV: DF_FLUSH failed, ret=%d. PSP returned error=%#x\n",
> +		       ret, error);

This specific text change does not seem to match the patch description.

> 
> 	return ret;
> }
> diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c
> index 39fdd06..c486c24 100644
> --- a/drivers/crypto/ccp/psp-dev.c
> +++ b/drivers/crypto/ccp/psp-dev.c
> @@ -155,6 +155,8 @@ static int __sev_do_cmd_locked(int cmd, void *data, int *psp_ret)
> 	unsigned int phys_lsb, phys_msb;
> 	unsigned int reg, ret = 0;
> 
> +	*psp_ret = -1;
> +
> 	if (!psp)
> 		return -ENODEV;
> 
> --
> 1.8.3.1

Re: [PATCH v2] KVM: SVM: Fix "error" isn't initialized

[Tom Lendacky]

On 11/27/19 1:23 AM, Haiwei Li wrote:
>  From e7f9c786e43ef4f890b8a01f15f8f00786f4b14a Mon Sep 17 00:00:00 2001
> From: Haiwei Li <lihaiwei@tencent.com>
> Date: Wed, 27 Nov 2019 15:00:49 +0800
> Subject: [PATCH v2] fix: 'error' is not initialized
> 
> There are a bunch of error paths were "error" isn't initialized.

Please provide a better patch commit message and just fix the actual
problem, which is error is uninitialized in sev_flush_asids(). Please
just initialize error to zero.

Thanks,
Tom

> 
> Signed-off-by: Haiwei Li <lihaiwei@tencent.com>
> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
>   arch/x86/kvm/svm.c           | 3 ++-
>   drivers/crypto/ccp/psp-dev.c | 2 ++
>   2 files changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
> index 362e874..9eef6fc 100644
> --- a/arch/x86/kvm/svm.c
> +++ b/arch/x86/kvm/svm.c
> @@ -6308,7 +6308,8 @@ static int sev_flush_asids(void)
>       up_write(&sev_deactivate_lock);
> 
>       if (ret)
> -        pr_err("SEV: DF_FLUSH failed, ret=%d, error=%#x\n", ret, error);
> +        pr_err("SEV: DF_FLUSH failed, ret=%d. PSP returned error=%#x\n",
> +               ret, error);
> 
>       return ret;
>   }
> diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c
> index 39fdd06..c486c24 100644
> --- a/drivers/crypto/ccp/psp-dev.c
> +++ b/drivers/crypto/ccp/psp-dev.c
> @@ -155,6 +155,8 @@ static int __sev_do_cmd_locked(int cmd, void *data, 
> int *psp_ret)
>       unsigned int phys_lsb, phys_msb;
>       unsigned int reg, ret = 0;
> 
> +    *psp_ret = -1;
> +
>       if (!psp)
>           return -ENODEV;
> 
> -- 
> 1.8.3.1

Re: [PATCH v2] KVM: SVM: Fix "error" isn't initialized

[linmiaohe]

> From e7f9c786e43ef4f890b8a01f15f8f00786f4b14a Mon Sep 17 00:00:00 2001
> From: Haiwei Li <lihaiwei@tencent.com>
> Date: Wed, 27 Nov 2019 15:00:49 +0800
> Subject: [PATCH v2] fix: 'error' is not initialized
>
> There are a bunch of error paths were "error" isn't initialized.
> @@ -155,6 +155,8 @@ static int __sev_do_cmd_locked(int cmd, void *data, int *psp_ret)
>   	unsigned int phys_lsb, phys_msb;
>   	unsigned int reg, ret = 0;
>
> +	*psp_ret = -1;
> +
>   	if (!psp)
>   		return -ENODEV;
>

The arg psp_ret may be NULL in some path such as sev_guest_df_flush(NULL).
So you have to check it against NULL.
Thanks.