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@xxxxxxxxx>
---
arch/x86/include/uapi/asm/sgx.h | 7 ++++++-
arch/x86/kernel/cpu/sgx/ioctl.c | 3 ++-
2 files changed, 8 insertions(+), 2 deletions(-)
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)))
--
2.22.0
