[PATCH 0/4] Remaining updates for v22

[PATCH 0/4] Remaining updates for v22

[Jarkko Sakkinen]

These are my remaining updates for v22.

Jarkko Sakkinen (4):
  x86/sgx: Replace @is_secs_child with @pt in sgx_encl_ewb()
  x86/sgx: Validate TCS permssions in sgx_validate_secinfo()
  x86/sgx: Remove a deperecated enum
  x86/sgx: Move VM prot bits calculation to sgx_encl_page_alloc()

 arch/x86/kernel/cpu/sgx/encl.h    |  6 ----
 arch/x86/kernel/cpu/sgx/ioctl.c   | 51 +++++++++++++++++--------------
 arch/x86/kernel/cpu/sgx/reclaim.c | 43 ++++++++++++++++----------
 3 files changed, 55 insertions(+), 45 deletions(-)

-- 
2.20.1

[PATCH 1/4] x86/sgx: Replace @is_secs_child with @pt in sgx_encl_ewb()

[Jarkko Sakkinen]

Sean complained about boolean parameters so I though that maybe it would
be good to rework the EWB flow in a way that it operates by a page type and
here is the result. The contract is and will be that as long as you give
the correct page type, you will get what you want. That is why I set
REG and TCS appropriately even though they are treated the same way
at this point of time.

Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
---
 arch/x86/kernel/cpu/sgx/reclaim.c | 43 +++++++++++++++++++------------
 1 file changed, 27 insertions(+), 16 deletions(-)

diff --git a/arch/x86/kernel/cpu/sgx/reclaim.c b/arch/x86/kernel/cpu/sgx/reclaim.c
index 00f596c64a2d..3f10a8ff00b7 100644
--- a/arch/x86/kernel/cpu/sgx/reclaim.c
+++ b/arch/x86/kernel/cpu/sgx/reclaim.c
@@ -221,7 +221,7 @@ static void sgx_reclaimer_block(struct sgx_epc_page *epc_page)
 
 static int __sgx_encl_ewb(struct sgx_encl *encl, struct sgx_epc_page *epc_page,
 			  struct sgx_va_page *va_page, unsigned int va_offset,
-			  bool is_secs_child)
+			  unsigned int pt)
 {
 	struct sgx_encl_page *encl_page = epc_page->owner;
 	struct sgx_pageinfo pginfo;
@@ -232,10 +232,14 @@ static int __sgx_encl_ewb(struct sgx_encl *encl, struct sgx_epc_page *epc_page,
 	struct page *pcmd;
 	int ret;
 
-	if (is_secs_child)
-		page_index = SGX_ENCL_PAGE_INDEX(encl_page);
-	else
+	if (pt != SGX_SECINFO_SECS && pt != SGX_SECINFO_TCS &&
+	    pt != SGX_SECINFO_REG)
+		return -EINVAL;
+
+	if (pt == SGX_SECINFO_SECS)
 		page_index = PFN_DOWN(encl->size);
+	else
+		page_index = SGX_ENCL_PAGE_INDEX(encl_page);
 
 	pcmd_index = sgx_pcmd_index(encl, page_index);
 	pcmd_offset = sgx_pcmd_offset(page_index);
@@ -300,7 +304,7 @@ static const cpumask_t *sgx_encl_ewb_cpumask(struct sgx_encl *encl)
 	return cpumask;
 }
 
-static void sgx_encl_ewb(struct sgx_epc_page *epc_page, bool is_secs_child)
+static void sgx_encl_ewb(struct sgx_epc_page *epc_page, unsigned int pt)
 {
 	struct sgx_encl_page *encl_page = epc_page->owner;
 	struct sgx_encl *encl = encl_page->encl;
@@ -317,8 +321,7 @@ static void sgx_encl_ewb(struct sgx_epc_page *epc_page, bool is_secs_child)
 		if (sgx_va_page_full(va_page))
 			list_move_tail(&va_page->list, &encl->va_pages);
 
-		ret = __sgx_encl_ewb(encl, epc_page, va_page, va_offset,
-				     is_secs_child);
+		ret = __sgx_encl_ewb(encl, epc_page, va_page, va_offset, pt);
 		if (ret == SGX_NOT_TRACKED) {
 			ret = __etrack(sgx_epc_addr(encl->secs.epc_page));
 			if (ret) {
@@ -327,8 +330,8 @@ static void sgx_encl_ewb(struct sgx_epc_page *epc_page, bool is_secs_child)
 					ENCLS_WARN(ret, "ETRACK");
 			}
 
-			ret = __sgx_encl_ewb(encl, epc_page, va_page,
-					     va_offset, is_secs_child);
+			ret = __sgx_encl_ewb(encl, epc_page, va_page, va_offset,
+					     pt);
 			if (ret == SGX_NOT_TRACKED) {
 				/*
 				 * Slow path, send IPIs to kick cpus out of the
@@ -340,7 +343,7 @@ static void sgx_encl_ewb(struct sgx_epc_page *epc_page, bool is_secs_child)
 				on_each_cpu_mask(sgx_encl_ewb_cpumask(encl),
 						 sgx_ipi_cb, NULL, 1);
 				ret = __sgx_encl_ewb(encl, epc_page, va_page,
-						     va_offset, is_secs_child);
+						     va_offset, pt);
 			}
 		}
 
@@ -350,12 +353,13 @@ static void sgx_encl_ewb(struct sgx_epc_page *epc_page, bool is_secs_child)
 
 		encl_page->desc |= va_offset;
 		encl_page->va_page = va_page;
-	} else if (is_secs_child) {
+	} else if (pt != SGX_SECINFO_SECS) {
 		ret = __eremove(sgx_epc_addr(epc_page));
 		WARN(ret, "EREMOVE returned %d\n", ret);
 	}
 
-	if (!is_secs_child)
+	/* The reclaimer is not aware of SECS pages. */
+	if (pt == SGX_SECINFO_SECS)
 		sgx_free_page(epc_page);
 
 	encl_page->epc_page = NULL;
@@ -365,15 +369,22 @@ static void sgx_reclaimer_write(struct sgx_epc_page *epc_page)
 {
 	struct sgx_encl_page *encl_page = epc_page->owner;
 	struct sgx_encl *encl = encl_page->encl;
+	unsigned int pt;
+
+	if (encl_page->desc & SGX_ENCL_PAGE_TCS)
+		pt = SGX_SECINFO_TCS;
+	else
+		pt = SGX_SECINFO_REG;
 
 	mutex_lock(&encl->lock);
 
-	sgx_encl_ewb(epc_page, true);
+	sgx_encl_ewb(epc_page, pt);
+
 	encl->secs_child_cnt--;
+
 	if (!encl->secs_child_cnt &&
-	    (encl->flags & (SGX_ENCL_DEAD | SGX_ENCL_INITIALIZED))) {
-		sgx_encl_ewb(encl->secs.epc_page, false);
-	}
+	    (encl->flags & (SGX_ENCL_DEAD | SGX_ENCL_INITIALIZED)))
+		sgx_encl_ewb(encl->secs.epc_page, SGX_SECINFO_SECS);
 
 	mutex_unlock(&encl->lock);
 }
-- 
2.20.1

RE: [PATCH 1/4] x86/sgx: Replace @is_secs_child with @pt in sgx_encl_ewb()

[Ayoun, Serge]

> On Behalf Of Jarkko Sakkinen
> Sent: Friday, August 23, 2019 19:16
> To: linux-sgx@vger.kernel.org
> Cc: Christopherson, Sean J <sean.j.christopherson@intel.com>; Ayoun,
> Serge <serge.ayoun@intel.com>; Katz-zamir, Shay <shay.katz-
> zamir@intel.com>; Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> Subject: [PATCH 1/4] x86/sgx: Replace @is_secs_child with @pt in
> sgx_encl_ewb()
> 
> Sean complained about boolean parameters so I though that maybe it would
> be good to rework the EWB flow in a way that it operates by a page type and
> here is the result. The contract is and will be that as long as you give the
> correct page type, you will get what you want. That is why I set REG and TCS
> appropriately even though they are treated the same way at this point of
> time.
> 
> Cc: Sean Christopherson <sean.j.christopherson@intel.com>
> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> ---
>  arch/x86/kernel/cpu/sgx/reclaim.c | 43 +++++++++++++++++++------------
>  1 file changed, 27 insertions(+), 16 deletions(-)
> 
> diff --git a/arch/x86/kernel/cpu/sgx/reclaim.c
> b/arch/x86/kernel/cpu/sgx/reclaim.c
> index 00f596c64a2d..3f10a8ff00b7 100644
> --- a/arch/x86/kernel/cpu/sgx/reclaim.c
> +++ b/arch/x86/kernel/cpu/sgx/reclaim.c
> @@ -221,7 +221,7 @@ static void sgx_reclaimer_block(struct sgx_epc_page
> *epc_page)
> 
>  static int __sgx_encl_ewb(struct sgx_encl *encl, struct sgx_epc_page
> *epc_page,
>  			  struct sgx_va_page *va_page, unsigned int
> va_offset,
> -			  bool is_secs_child)
> +			  unsigned int pt)
>  {
>  	struct sgx_encl_page *encl_page = epc_page->owner;
>  	struct sgx_pageinfo pginfo;
> @@ -232,10 +232,14 @@ static int __sgx_encl_ewb(struct sgx_encl *encl,
> struct sgx_epc_page *epc_page,
>  	struct page *pcmd;
>  	int ret;
> 
> -	if (is_secs_child)
> -		page_index = SGX_ENCL_PAGE_INDEX(encl_page);
> -	else
> +	if (pt != SGX_SECINFO_SECS && pt != SGX_SECINFO_TCS &&
> +	    pt != SGX_SECINFO_REG)
> +		return -EINVAL;

Not sure about this one since this 'if' should never happen, unless there is a bug
Not clear if the caller (sgx_encl_ewb) will handle -EINVAL properly.
Maybe would be better to issue some warning message or BUG_ON

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Re: [PATCH 1/4] x86/sgx: Replace @is_secs_child with @pt in sgx_encl_ewb()

[Jarkko Sakkinen]

On Mon, Aug 26, 2019 at 02:31:54PM +0000, Ayoun, Serge wrote:
> Not sure about this one since this 'if' should never happen, unless there is a bug
> Not clear if the caller (sgx_encl_ewb) will handle -EINVAL properly.
> Maybe would be better to issue some warning message or BUG_ON

The caller issues warning.

/Jarkko

[PATCH 2/4] x86/sgx: Validate TCS permssions in sgx_validate_secinfo()

[Jarkko Sakkinen]

The validation of TCS permissions was missing from
sgx_validate_secinfo(). This patch adds the validation.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
---
 arch/x86/kernel/cpu/sgx/ioctl.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c
index f9eef0f2125f..5423d7c45d5e 100644
--- a/arch/x86/kernel/cpu/sgx/ioctl.c
+++ b/arch/x86/kernel/cpu/sgx/ioctl.c
@@ -298,6 +298,13 @@ static int sgx_validate_secinfo(struct sgx_secinfo *secinfo)
 	if ((perm & SGX_SECINFO_W) && !(perm & SGX_SECINFO_R))
 		return -EINVAL;
 
+	/*
+	 * CPU will silently overwrite the permissions as zero, which means
+	 * that we need to validate it ourselves.
+	 */
+	if (pt == SGX_SECINFO_TCS && perm)
+		return -EINVAL;
+
 	if (secinfo->flags & SGX_SECINFO_RESERVED_MASK)
 		return -EINVAL;
 
-- 
2.20.1

[PATCH 3/4] x86/sgx: Remove a deperecated enum

[Jarkko Sakkinen]

&sgx_encl_mm_iter is no longer used for anything.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
---
 arch/x86/kernel/cpu/sgx/encl.h | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/arch/x86/kernel/cpu/sgx/encl.h b/arch/x86/kernel/cpu/sgx/encl.h
index cc1f8c4b1472..37b5c4bcda7a 100644
--- a/arch/x86/kernel/cpu/sgx/encl.h
+++ b/arch/x86/kernel/cpu/sgx/encl.h
@@ -109,12 +109,6 @@ static inline unsigned long sgx_pcmd_offset(pgoff_t page_index)
 	       sizeof(struct sgx_pcmd);
 }
 
-enum sgx_encl_mm_iter {
-	SGX_ENCL_MM_ITER_DONE		= 0,
-	SGX_ENCL_MM_ITER_NEXT		= 1,
-	SGX_ENCL_MM_ITER_RESTART	= 2,
-};
-
 int sgx_encl_find(struct mm_struct *mm, unsigned long addr,
 		  struct vm_area_struct **vma);
 void sgx_encl_destroy(struct sgx_encl *encl);
-- 
2.20.1

[PATCH 4/4] x86/sgx: Move VM prot bits calculation to sgx_encl_page_alloc()

[Jarkko Sakkinen]

Move full VM prot bits calculation to sgx_encl_page_alloc() so that we
don't pass duplicate data in the add page flow (@prot and @secinfo hold
intersecting data).

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
---
 arch/x86/kernel/cpu/sgx/ioctl.c | 44 ++++++++++++++++-----------------
 1 file changed, 21 insertions(+), 23 deletions(-)

diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c
index 5423d7c45d5e..ead9fb2d9b69 100644
--- a/arch/x86/kernel/cpu/sgx/ioctl.c
+++ b/arch/x86/kernel/cpu/sgx/ioctl.c
@@ -130,10 +130,10 @@ static int sgx_validate_secs(const struct sgx_secs *secs,
 
 static struct sgx_encl_page *sgx_encl_page_alloc(struct sgx_encl *encl,
 						 unsigned long addr,
-						 unsigned long prot,
-						 u64 page_type)
+						 u64 secinfo_flags)
 {
 	struct sgx_encl_page *encl_page;
+       unsigned long prot;
 
 	encl_page = kzalloc(sizeof(*encl_page), GFP_KERNEL);
 	if (!encl_page)
@@ -142,9 +142,22 @@ static struct sgx_encl_page *sgx_encl_page_alloc(struct sgx_encl *encl,
 	encl_page->desc = addr;
 	encl_page->encl = encl;
 
-	if (page_type == SGX_SECINFO_TCS)
+	if (secinfo_flags & SGX_SECINFO_TCS)
 		encl_page->desc |= SGX_ENCL_PAGE_TCS;
 
+
+       prot = _calc_vm_trans(secinfo_flags, SGX_SECINFO_R, PROT_READ)  |
+	      _calc_vm_trans(secinfo_flags, SGX_SECINFO_W, PROT_WRITE) |
+	      _calc_vm_trans(secinfo_flags, SGX_SECINFO_X, PROT_EXEC);
+
+       /*
+	* TCS pages must always RW set for CPU access while the SECINFO
+	* permissions are *always* zero - the CPU ignores the user provided
+	* values and silently overwrites them with zero permissions.
+	*/
+       if ((secinfo_flags & SGX_SECINFO_PAGE_TYPE_MASK) == SGX_SECINFO_TCS)
+	       prot |= PROT_READ | PROT_WRITE;
+
 	/* Calculate maximum of the VM flags for the page. */
 	encl_page->vm_max_prot_bits = calc_vm_prot_bits(prot, 0);
 
@@ -318,7 +331,7 @@ static int __sgx_encl_add_page(struct sgx_encl *encl,
 			       struct sgx_encl_page *encl_page,
 			       struct sgx_epc_page *epc_page,
 			       struct sgx_secinfo *secinfo, unsigned long src,
-			       unsigned long prot, unsigned long mrmask)
+			       unsigned long mrmask)
 {
 	struct sgx_pageinfo pginfo;
 	struct vm_area_struct *vma;
@@ -375,15 +388,14 @@ static int __sgx_encl_add_page(struct sgx_encl *encl,
 
 static int sgx_encl_add_page(struct sgx_encl *encl,
 			     struct sgx_enclave_add_page *addp,
-			     struct sgx_secinfo *secinfo, unsigned long prot)
+			     struct sgx_secinfo *secinfo)
 {
-	u64 page_type = secinfo->flags & SGX_SECINFO_PAGE_TYPE_MASK;
 	struct sgx_encl_page *encl_page;
 	struct sgx_epc_page *epc_page;
 	struct sgx_va_page *va_page;
 	int ret;
 
-	encl_page = sgx_encl_page_alloc(encl, addp->addr, prot, page_type);
+	encl_page = sgx_encl_page_alloc(encl, addp->addr, secinfo->flags);
 	if (IS_ERR(encl_page))
 		return PTR_ERR(encl_page);
 
@@ -407,7 +419,7 @@ static int sgx_encl_add_page(struct sgx_encl *encl,
 		goto err_out_shrink;
 
 	ret = __sgx_encl_add_page(encl, encl_page, epc_page, secinfo,
-				  addp->src, prot, addp->mrmask);
+				  addp->src, addp->mrmask);
 	if (ret)
 		goto err_out;
 
@@ -450,7 +462,6 @@ static long sgx_ioc_enclave_add_page(struct file *filep, void __user *arg)
 	struct sgx_encl *encl = filep->private_data;
 	struct sgx_enclave_add_page addp;
 	struct sgx_secinfo secinfo;
-	unsigned long prot;
 
 	if (!(encl->flags & SGX_ENCL_CREATED))
 		return -EINVAL;
@@ -472,20 +483,7 @@ static long sgx_ioc_enclave_add_page(struct file *filep, void __user *arg)
 	if (sgx_validate_secinfo(&secinfo))
 		return -EINVAL;
 
-	/* Set prot bits matching to the SECINFO permissions. */
-	prot = _calc_vm_trans(secinfo.flags, SGX_SECINFO_R, PROT_READ)  |
-	       _calc_vm_trans(secinfo.flags, SGX_SECINFO_W, PROT_WRITE) |
-	       _calc_vm_trans(secinfo.flags, SGX_SECINFO_X, PROT_EXEC);
-
-	/*
-	 * TCS pages must always RW set for CPU access while the SECINFO
-	 * permissions are *always* zero - the CPU ignores the user provided
-	 * values and silently overwrites with zero permissions.
-	 */
-	if ((secinfo.flags & SGX_SECINFO_PAGE_TYPE_MASK) == SGX_SECINFO_TCS)
-		prot |= PROT_READ | PROT_WRITE;
-
-	return sgx_encl_add_page(encl, &addp, &secinfo, prot);
+	return sgx_encl_add_page(encl, &addp, &secinfo);
 }
 
 static int __sgx_get_key_hash(struct crypto_shash *tfm, const void *modulus,
-- 
2.20.1

Re: [PATCH 0/4] Remaining updates for v22

[Sean Christopherson]

On Fri, Aug 23, 2019 at 07:16:12PM +0300, Jarkko Sakkinen wrote:
> These are my remaining updates for v22.

Tested, no issues found.

> 
> Jarkko Sakkinen (4):
>   x86/sgx: Replace @is_secs_child with @pt in sgx_encl_ewb()
>   x86/sgx: Validate TCS permssions in sgx_validate_secinfo()
>   x86/sgx: Remove a deperecated enum
>   x86/sgx: Move VM prot bits calculation to sgx_encl_page_alloc()
> 
>  arch/x86/kernel/cpu/sgx/encl.h    |  6 ----
>  arch/x86/kernel/cpu/sgx/ioctl.c   | 51 +++++++++++++++++--------------
>  arch/x86/kernel/cpu/sgx/reclaim.c | 43 ++++++++++++++++----------
>  3 files changed, 55 insertions(+), 45 deletions(-)
> 
> -- 
> 2.20.1
> 

Re: [PATCH 0/4] Remaining updates for v22

[Jarkko Sakkinen]

On Fri, Aug 23, 2019 at 02:53:27PM -0700, Sean Christopherson wrote:
> On Fri, Aug 23, 2019 at 07:16:12PM +0300, Jarkko Sakkinen wrote:
> > These are my remaining updates for v22.
> 
> Tested, no issues found.

Awesome, thank you.

/Jarkko