diff mbox series

[v2] x86/sgx: Remove checks for platform limits from sgx_validate_secs()

Message ID 20201005033803.158793-1-jarkko.sakkinen@linux.intel.com
State New, archived
Headers show
Series [v2] x86/sgx: Remove checks for platform limits from sgx_validate_secs() | expand

Commit Message

Jarkko Sakkinen Oct. 5, 2020, 3:38 a.m. UTC
Remove from sgx_validate_secs():

	if (secs->miscselect & sgx_misc_reserved_mask ||
	    secs->attributes & sgx_attributes_reserved_mask ||
	    secs->xfrm & sgx_xfrm_reserved_mask)
		return -EINVAL;

SECS can surpass the platform limits because it's the SIGSTRUCT that
defines the limits that are used at run-time.

What SECS does is that it defines the overall limits that must apply for
any platform, i.e. SECS limits and platform limits are orthogonal. They are
not dependent.

Rename sgx_*_reserved_mask as sgx_cpu_* in order to bring some clarity
and separate them from SIGSTRUCT limits.

Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Jethro Beekman <jethro@fortanix.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Suggested-by: Haitao Huang <haitao.huang@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
---
v2: Rename sgx_*_reserved_mask as sgx_cpu_*.
 arch/x86/kernel/cpu/sgx/driver.c | 12 ++++++------
 arch/x86/kernel/cpu/sgx/driver.h |  6 +++---
 arch/x86/kernel/cpu/sgx/ioctl.c  | 11 +++--------
 3 files changed, 12 insertions(+), 17 deletions(-)

Comments

Jarkko Sakkinen Oct. 5, 2020, 3:41 a.m. UTC | #1
On Mon, Oct 05, 2020 at 06:38:03AM +0300, Jarkko Sakkinen wrote:
> Remove from sgx_validate_secs():
> 
> 	if (secs->miscselect & sgx_misc_reserved_mask ||
> 	    secs->attributes & sgx_attributes_reserved_mask ||
> 	    secs->xfrm & sgx_xfrm_reserved_mask)
> 		return -EINVAL;
> 
> SECS can surpass the platform limits because it's the SIGSTRUCT that
> defines the limits that are used at run-time.
> 
> What SECS does is that it defines the overall limits that must apply for
> any platform, i.e. SECS limits and platform limits are orthogonal. They are
> not dependent.
> 
> Rename sgx_*_reserved_mask as sgx_cpu_* in order to bring some clarity
> and separate them from SIGSTRUCT limits.
> 
> Cc: Sean Christopherson <sean.j.christopherson@intel.com>
> Cc: Jethro Beekman <jethro@fortanix.com>
> Cc: Dave Hansen <dave.hansen@linux.intel.com>
> Suggested-by: Haitao Huang <haitao.huang@linux.intel.com>
> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

Ugh, forgot that the masks are describing things that *are not*
allowed. Please just ignore this version. I'll take the first
version.

NAK from my side.

/Jarkko
diff mbox series

Patch

diff --git a/arch/x86/kernel/cpu/sgx/driver.c b/arch/x86/kernel/cpu/sgx/driver.c
index e8b6da3d8f58..181c4b5c402c 100644
--- a/arch/x86/kernel/cpu/sgx/driver.c
+++ b/arch/x86/kernel/cpu/sgx/driver.c
@@ -12,9 +12,9 @@ 
 
 u64 sgx_encl_size_max_32;
 u64 sgx_encl_size_max_64;
-u32 sgx_misc_reserved_mask;
-u64 sgx_attributes_reserved_mask;
-u64 sgx_xfrm_reserved_mask = ~0x3;
+u32 sgx_cpu_misc;
+u64 sgx_cpu_attributes;
+u64 sgx_cpu_xfrm = ~0x3;
 u32 sgx_xsave_size_tbl[64];
 
 static int sgx_open(struct inode *inode, struct file *file)
@@ -166,14 +166,14 @@  int __init sgx_drv_init(void)
 	}
 
 	cpuid_count(SGX_CPUID, 0, &eax, &ebx, &ecx, &edx);
-	sgx_misc_reserved_mask = ~ebx | SGX_MISC_RESERVED_MASK;
+	sgx_cpu_misc = ~ebx | SGX_MISC_RESERVED_MASK;
 	sgx_encl_size_max_64 = 1ULL << ((edx >> 8) & 0xFF);
 	sgx_encl_size_max_32 = 1ULL << (edx & 0xFF);
 
 	cpuid_count(SGX_CPUID, 1, &eax, &ebx, &ecx, &edx);
 
 	attr_mask = (((u64)ebx) << 32) + (u64)eax;
-	sgx_attributes_reserved_mask = ~attr_mask | SGX_ATTR_RESERVED_MASK;
+	sgx_cpu_attributes = ~attr_mask | SGX_ATTR_RESERVED_MASK;
 
 	if (boot_cpu_has(X86_FEATURE_OSXSAVE)) {
 		xfrm_mask = (((u64)edx) << 32) + (u64)ecx;
@@ -184,7 +184,7 @@  int __init sgx_drv_init(void)
 				sgx_xsave_size_tbl[i] = eax + ebx;
 		}
 
-		sgx_xfrm_reserved_mask = ~xfrm_mask;
+		sgx_cpu_xfrm = ~xfrm_mask;
 	}
 
 	ret = misc_register(&sgx_dev_enclave);
diff --git a/arch/x86/kernel/cpu/sgx/driver.h b/arch/x86/kernel/cpu/sgx/driver.h
index fd81b8818600..204866065c2f 100644
--- a/arch/x86/kernel/cpu/sgx/driver.h
+++ b/arch/x86/kernel/cpu/sgx/driver.h
@@ -18,9 +18,9 @@ 
 
 extern u64 sgx_encl_size_max_32;
 extern u64 sgx_encl_size_max_64;
-extern u32 sgx_misc_reserved_mask;
-extern u64 sgx_attributes_reserved_mask;
-extern u64 sgx_xfrm_reserved_mask;
+extern u32 sgx_cpu_misc;
+extern u64 sgx_cpu_attributes;
+extern u64 sgx_cpu_xfrm;
 extern u32 sgx_xsave_size_tbl[64];
 
 extern const struct file_operations sgx_provision_fops;
diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c
index 6b3cc8483008..373ffde3f8c5 100644
--- a/arch/x86/kernel/cpu/sgx/ioctl.c
+++ b/arch/x86/kernel/cpu/sgx/ioctl.c
@@ -86,11 +86,6 @@  static int sgx_validate_secs(const struct sgx_secs *secs)
 	if (secs->base & (secs->size - 1))
 		return -EINVAL;
 
-	if (secs->miscselect & sgx_misc_reserved_mask ||
-	    secs->attributes & sgx_attributes_reserved_mask ||
-	    secs->xfrm & sgx_xfrm_reserved_mask)
-		return -EINVAL;
-
 	if (secs->size > max_size)
 		return -EINVAL;
 
@@ -611,15 +606,15 @@  static int sgx_encl_init(struct sgx_encl *encl, struct sgx_sigstruct *sigstruct,
 	 * bit on.
 	 */
 	if (sigstruct->body.attributes & sigstruct->body.attributes_mask &
-	    sgx_attributes_reserved_mask)
+	    sgx_cpu_attributes)
 		return -EINVAL;
 
 	if (sigstruct->body.miscselect & sigstruct->body.misc_mask &
-	    sgx_misc_reserved_mask)
+	    sgx_cpu_misc)
 		return -EINVAL;
 
 	if (sigstruct->body.xfrm & sigstruct->body.xfrm_mask &
-	    sgx_xfrm_reserved_mask)
+	    sgx_cpu_xfrm)
 		return -EINVAL;
 
 	ret = sgx_get_key_hash(sigstruct->modulus, mrsigner);