diff mbox series

x86/sgx: Refine rollback in SGX_IOC_ENCLAVE_ADD_PAGE

Message ID 20200918130226.39530-1-jarkko.sakkinen@linux.intel.com (mailing list archive)
State New, archived
Headers show
Series x86/sgx: Refine rollback in SGX_IOC_ENCLAVE_ADD_PAGE | expand

Commit Message

Jarkko Sakkinen Sept. 18, 2020, 1:02 p.m. UTC
Revert back 'count' to struct sgx_enclave_add_pages as in most of the
cases enclave can be recovered. Refine the documentation to better
describe the enclave is persisted.

Move the check for -EIO from sgx_encl_add_page() to
sgx_ioc_enclave_pages() to make it more visible. It was quite
hidden over there.

Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Haitao Huang <haitao.huang@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
---
 arch/x86/include/uapi/asm/sgx.h | 12 +++++++-----
 arch/x86/kernel/cpu/sgx/ioctl.c | 29 ++++++++++++++---------------
 2 files changed, 21 insertions(+), 20 deletions(-)

Comments

Haitao Huang Sept. 28, 2020, 9:24 p.m. UTC | #1
On Fri, 18 Sep 2020 08:02:26 -0500, Jarkko Sakkinen  
<jarkko.sakkinen@linux.intel.com> wrote:

> Revert back 'count' to struct sgx_enclave_add_pages as in most of the
> cases enclave can be recovered. Refine the documentation to better
> describe the enclave is persisted.
>
> Move the check for -EIO from sgx_encl_add_page() to
> sgx_ioc_enclave_pages() to make it more visible. It was quite
> hidden over there.
>
> Cc: Sean Christopherson <sean.j.christopherson@intel.com>
> Cc: Haitao Huang <haitao.huang@linux.intel.com>
> Cc: Borislav Petkov <bp@alien8.de>
> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> ---
>  arch/x86/include/uapi/asm/sgx.h | 12 +++++++-----
>  arch/x86/kernel/cpu/sgx/ioctl.c | 29 ++++++++++++++---------------
>  2 files changed, 21 insertions(+), 20 deletions(-)
>
> diff --git a/arch/x86/include/uapi/asm/sgx.h  
> b/arch/x86/include/uapi/asm/sgx.h
> index 1564d7f88597..ec5157b2ff50 100644
> --- a/arch/x86/include/uapi/asm/sgx.h
> +++ b/arch/x86/include/uapi/asm/sgx.h
> @@ -45,13 +45,15 @@ struct sgx_enclave_create  {
>   * @length:	length of the data (multiple of the page size)
>   * @secinfo:	address for the SECINFO data
>   * @flags:	page control flags
> + * @count:	number of bytes added (multiple of the page size)
>   */
>  struct sgx_enclave_add_pages {
> -	__u64	src;
> -	__u64	offset;
> -	__u64	length;
> -	__u64	secinfo;
> -	__u64	flags;
> +	__u64 src;
> +	__u64 offset;
> +	__u64 length;
> +	__u64 secinfo;
> +	__u64 flags;
> +	__u64 count;
>  };
> /**
> diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c  
> b/arch/x86/kernel/cpu/sgx/ioctl.c
> index 30de66f4247b..d10179b47daa 100644
> --- a/arch/x86/kernel/cpu/sgx/ioctl.c
> +++ b/arch/x86/kernel/cpu/sgx/ioctl.c
> @@ -449,16 +449,6 @@ static int sgx_encl_add_page(struct sgx_encl *encl,  
> unsigned long src,
>  	sgx_free_epc_page(epc_page);
>  	kfree(encl_page);
> -	/*
> -	 * Destroy enclave on ENCLS failure as this means that EPC has been
> -	 * invalidated.
> -	 */
> -	if (ret == -EIO) {
> -		mutex_lock(&encl->lock);
> -		sgx_encl_destroy(encl);
> -		mutex_unlock(&encl->lock);
> -	}
> -
>  	return ret;
>  }
> @@ -487,12 +477,15 @@ static int sgx_encl_add_page(struct sgx_encl  
> *encl, unsigned long src,
>   *
>   * If ENCLS opcode fails, that effectively means that EPC has been  
> invalidated.
>   * When this happens the enclave is destroyed and -EIO is returned to  
> the
> - * caller.
> + * caller. In this situation the function destroys the enclave as it  
> cannot
> + * be recovered.
>   *
>   * Return:
>   *   length of the data processed on success,
>   *   -EACCES if an executable source page is located in a noexec  
> partition,
> - *   -EIO if either ENCLS[EADD] or ENCLS[EEXTEND] fails
> + *   -ENOMEM if the system is out of EPC pages,
> + *   -EINTR if the call was interrupted before any data was processed,
> + *   -EIO if either ENCLS[EADD] or ENCLS[EEXTEND] fails,
>   *   -errno otherwise
>   */
>  static long sgx_ioc_enclave_add_pages(struct sgx_encl *encl, void  
> __user *arg)
> @@ -549,10 +542,16 @@ static long sgx_ioc_enclave_add_pages(struct  
> sgx_encl *encl, void __user *arg)
>  			break;
>  	}
> -	if (ret)
> -		return ret;
> +	addp.count = c;
> +
> +	/* On EADD or EEXTEND failure, destroy the enclave. */
> +	if (ret == -EIO) {
> +		mutex_lock(&encl->lock);
> +		sgx_encl_destroy(encl);
> +		mutex_unlock(&encl->lock);
> +	}
> -	return c;

missing copy_to_user for addp.count?

> +	return ret;
>  }
> static int __sgx_get_key_hash(struct crypto_shash *tfm, const void  
> *modulus,
Jarkko Sakkinen Sept. 30, 2020, 12:36 a.m. UTC | #2
On Mon, Sep 28, 2020 at 04:24:23PM -0500, Haitao Huang wrote:
> On Fri, 18 Sep 2020 08:02:26 -0500, Jarkko Sakkinen
> <jarkko.sakkinen@linux.intel.com> wrote:
> 
> > Revert back 'count' to struct sgx_enclave_add_pages as in most of the
> > cases enclave can be recovered. Refine the documentation to better
> > describe the enclave is persisted.
> > 
> > Move the check for -EIO from sgx_encl_add_page() to
> > sgx_ioc_enclave_pages() to make it more visible. It was quite
> > hidden over there.
> > 
> > Cc: Sean Christopherson <sean.j.christopherson@intel.com>
> > Cc: Haitao Huang <haitao.huang@linux.intel.com>
> > Cc: Borislav Petkov <bp@alien8.de>
> > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> > ---
> >  arch/x86/include/uapi/asm/sgx.h | 12 +++++++-----
> >  arch/x86/kernel/cpu/sgx/ioctl.c | 29 ++++++++++++++---------------
> >  2 files changed, 21 insertions(+), 20 deletions(-)
> > 
> > diff --git a/arch/x86/include/uapi/asm/sgx.h
> > b/arch/x86/include/uapi/asm/sgx.h
> > index 1564d7f88597..ec5157b2ff50 100644
> > --- a/arch/x86/include/uapi/asm/sgx.h
> > +++ b/arch/x86/include/uapi/asm/sgx.h
> > @@ -45,13 +45,15 @@ struct sgx_enclave_create  {
> >   * @length:	length of the data (multiple of the page size)
> >   * @secinfo:	address for the SECINFO data
> >   * @flags:	page control flags
> > + * @count:	number of bytes added (multiple of the page size)
> >   */
> >  struct sgx_enclave_add_pages {
> > -	__u64	src;
> > -	__u64	offset;
> > -	__u64	length;
> > -	__u64	secinfo;
> > -	__u64	flags;
> > +	__u64 src;
> > +	__u64 offset;
> > +	__u64 length;
> > +	__u64 secinfo;
> > +	__u64 flags;
> > +	__u64 count;
> >  };
> > /**
> > diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c
> > b/arch/x86/kernel/cpu/sgx/ioctl.c
> > index 30de66f4247b..d10179b47daa 100644
> > --- a/arch/x86/kernel/cpu/sgx/ioctl.c
> > +++ b/arch/x86/kernel/cpu/sgx/ioctl.c
> > @@ -449,16 +449,6 @@ static int sgx_encl_add_page(struct sgx_encl *encl,
> > unsigned long src,
> >  	sgx_free_epc_page(epc_page);
> >  	kfree(encl_page);
> > -	/*
> > -	 * Destroy enclave on ENCLS failure as this means that EPC has been
> > -	 * invalidated.
> > -	 */
> > -	if (ret == -EIO) {
> > -		mutex_lock(&encl->lock);
> > -		sgx_encl_destroy(encl);
> > -		mutex_unlock(&encl->lock);
> > -	}
> > -
> >  	return ret;
> >  }
> > @@ -487,12 +477,15 @@ static int sgx_encl_add_page(struct sgx_encl
> > *encl, unsigned long src,
> >   *
> >   * If ENCLS opcode fails, that effectively means that EPC has been
> > invalidated.
> >   * When this happens the enclave is destroyed and -EIO is returned to
> > the
> > - * caller.
> > + * caller. In this situation the function destroys the enclave as it
> > cannot
> > + * be recovered.
> >   *
> >   * Return:
> >   *   length of the data processed on success,
> >   *   -EACCES if an executable source page is located in a noexec
> > partition,
> > - *   -EIO if either ENCLS[EADD] or ENCLS[EEXTEND] fails
> > + *   -ENOMEM if the system is out of EPC pages,
> > + *   -EINTR if the call was interrupted before any data was processed,
> > + *   -EIO if either ENCLS[EADD] or ENCLS[EEXTEND] fails,
> >   *   -errno otherwise
> >   */
> >  static long sgx_ioc_enclave_add_pages(struct sgx_encl *encl, void
> > __user *arg)
> > @@ -549,10 +542,16 @@ static long sgx_ioc_enclave_add_pages(struct
> > sgx_encl *encl, void __user *arg)
> >  			break;
> >  	}
> > -	if (ret)
> > -		return ret;
> > +	addp.count = c;
> > +
> > +	/* On EADD or EEXTEND failure, destroy the enclave. */
> > +	if (ret == -EIO) {
> > +		mutex_lock(&encl->lock);
> > +		sgx_encl_destroy(encl);
> > +		mutex_unlock(&encl->lock);
> > +	}
> > -	return c;
> 
> missing copy_to_user for addp.count?

This somewhat deprecated patch. It's now all fixed in my master
branch.

/Jarkko
diff mbox series

Patch

diff --git a/arch/x86/include/uapi/asm/sgx.h b/arch/x86/include/uapi/asm/sgx.h
index 1564d7f88597..ec5157b2ff50 100644
--- a/arch/x86/include/uapi/asm/sgx.h
+++ b/arch/x86/include/uapi/asm/sgx.h
@@ -45,13 +45,15 @@  struct sgx_enclave_create  {
  * @length:	length of the data (multiple of the page size)
  * @secinfo:	address for the SECINFO data
  * @flags:	page control flags
+ * @count:	number of bytes added (multiple of the page size)
  */
 struct sgx_enclave_add_pages {
-	__u64	src;
-	__u64	offset;
-	__u64	length;
-	__u64	secinfo;
-	__u64	flags;
+	__u64 src;
+	__u64 offset;
+	__u64 length;
+	__u64 secinfo;
+	__u64 flags;
+	__u64 count;
 };
 
 /**
diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c
index 30de66f4247b..d10179b47daa 100644
--- a/arch/x86/kernel/cpu/sgx/ioctl.c
+++ b/arch/x86/kernel/cpu/sgx/ioctl.c
@@ -449,16 +449,6 @@  static int sgx_encl_add_page(struct sgx_encl *encl, unsigned long src,
 	sgx_free_epc_page(epc_page);
 	kfree(encl_page);
 
-	/*
-	 * Destroy enclave on ENCLS failure as this means that EPC has been
-	 * invalidated.
-	 */
-	if (ret == -EIO) {
-		mutex_lock(&encl->lock);
-		sgx_encl_destroy(encl);
-		mutex_unlock(&encl->lock);
-	}
-
 	return ret;
 }
 
@@ -487,12 +477,15 @@  static int sgx_encl_add_page(struct sgx_encl *encl, unsigned long src,
  *
  * If ENCLS opcode fails, that effectively means that EPC has been invalidated.
  * When this happens the enclave is destroyed and -EIO is returned to the
- * caller.
+ * caller. In this situation the function destroys the enclave as it cannot
+ * be recovered.
  *
  * Return:
  *   length of the data processed on success,
  *   -EACCES if an executable source page is located in a noexec partition,
- *   -EIO if either ENCLS[EADD] or ENCLS[EEXTEND] fails
+ *   -ENOMEM if the system is out of EPC pages,
+ *   -EINTR if the call was interrupted before any data was processed,
+ *   -EIO if either ENCLS[EADD] or ENCLS[EEXTEND] fails,
  *   -errno otherwise
  */
 static long sgx_ioc_enclave_add_pages(struct sgx_encl *encl, void __user *arg)
@@ -549,10 +542,16 @@  static long sgx_ioc_enclave_add_pages(struct sgx_encl *encl, void __user *arg)
 			break;
 	}
 
-	if (ret)
-		return ret;
+	addp.count = c;
+
+	/* On EADD or EEXTEND failure, destroy the enclave. */
+	if (ret == -EIO) {
+		mutex_lock(&encl->lock);
+		sgx_encl_destroy(encl);
+		mutex_unlock(&encl->lock);
+	}
 
-	return c;
+	return ret;
 }
 
 static int __sgx_get_key_hash(struct crypto_shash *tfm, const void *modulus,