diff mbox series

[for_v23,5/7] x86/sgx: Add a flag to ADD_PAGES to allow replicating the source page

Message ID 20191009044241.3591-6-sean.j.christopherson@intel.com (mailing list archive)
State New, archived
Headers show
Series x86/sgx: Improve add pages ioctl | expand

Commit Message

Sean Christopherson Oct. 9, 2019, 4:42 a.m. UTC 
Add a flag to allow userspace to replicate a single source page to
multiple target pages in the enclave, e.g. to zero the .bss, initialize
the heap, etc...

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
 arch/x86/include/uapi/asm/sgx.h | 7 ++++++-
 arch/x86/kernel/cpu/sgx/ioctl.c | 3 ++-
 2 files changed, 8 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/arch/x86/include/uapi/asm/sgx.h b/arch/x86/include/uapi/asm/sgx.h
index 84734229d8dd..42634e99945e 100644
--- a/arch/x86/include/uapi/asm/sgx.h
+++ b/arch/x86/include/uapi/asm/sgx.h
@@ -28,6 +28,9 @@  struct sgx_enclave_create  {
 	__u64	src;
 };
 
+/* Replicate a single source data page to all target pages. */
+#define SGX_ADD_PAGES_REPLICATE_SRC	BIT(0)
+
 /**
  * struct sgx_enclave_add_pages - parameter structure for the
  *                                %SGX_IOC_ENCLAVE_ADD_PAGE ioctl
@@ -35,6 +38,7 @@  struct sgx_enclave_create  {
  * @src:	start address for the page data
  * @nr_pages:	number of pages to add to enclave
  * @secinfo:	address for the SECINFO data
+ * @flags:	misc control flags
  * @mrmask:	bitmask for the measured 256 byte chunks
  * @reserved:	reserved for future use
  */
@@ -43,8 +47,9 @@  struct sgx_enclave_add_pages {
 	__u64	src;
 	__u64	nr_pages;
 	__u64	secinfo;
+	__u32	flags;
 	__u16	mrmask;
-	__u8	reserved[6];
+	__u8	reserved[2];
 };
 
 /**
diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c
index 4597dd8f5c91..9c6d582612cb 100644
--- a/arch/x86/kernel/cpu/sgx/ioctl.c
+++ b/arch/x86/kernel/cpu/sgx/ioctl.c
@@ -529,7 +529,8 @@  static long sgx_ioc_enclave_add_pages(struct sgx_encl *encl, void __user *arg)
 			break;
 
 		addp.offset += PAGE_SIZE;
-		addp.src += PAGE_SIZE;
+		if (!(addp.flags & SGX_ADD_PAGES_REPLICATE_SRC))
+			addp.src += PAGE_SIZE;
 	}
 
 	if (copy_to_user(arg, &addp, sizeof(addp)))