selftests/sgx: Assign source for each segment

Define source per segment so that enclave pages can be added from different
sources, e.g. anonymous VMA for zero pages. In other words, add 'src' field
to struct encl_segment, and assign it to 'encl->src' for pages inherited
from the enclave binary.
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lkml.kernel.org/r/7850709c3089fe20e4bcecb8295ba87c54cc2b4a.1636997631.git.reinette.chatre@intel.com

tools/testing/selftests/sgx/load.c

@@ -107,7 +107,7 @@ static bool encl_ioc_add_pages(struct encl *encl, struct encl_segment *seg)
 	memset(&secinfo, 0, sizeof(secinfo));
 	secinfo.flags = seg->flags;
 
-	ioc.src = (uint64_t)encl->src + seg->offset;
+	ioc.src = (uint64_t)seg->src;
 	ioc.offset = seg->offset;
 	ioc.length = seg->size;
 	ioc.secinfo = (unsigned long)&secinfo;
@@ -216,6 +216,7 @@ bool encl_load(const char *path, struct encl *encl)
 
 		if (j == 0) {
 			src_offset = phdr->p_offset & PAGE_MASK;
+			encl->src = encl->bin + src_offset;
 
 			seg->prot = PROT_READ | PROT_WRITE;
 			seg->flags = SGX_PAGE_TYPE_TCS << 8;
@@ -228,13 +229,13 @@ bool encl_load(const char *path, struct encl *encl)
 
 		seg->offset = (phdr->p_offset & PAGE_MASK) - src_offset;
 		seg->size = (phdr->p_filesz + PAGE_SIZE - 1) & PAGE_MASK;
+		seg->src = encl->src + seg->offset;
 
 		j++;
 	}
 
 	assert(j == encl->nr_segments);
 
-	encl->src = encl->bin + src_offset;
 	encl->src_size = encl->segment_tbl[j - 1].offset +
 			 encl->segment_tbl[j - 1].size;
 

tools/testing/selftests/sgx/main.h

@@ -7,6 +7,7 @@
 #define MAIN_H
 
 struct encl_segment {
+	void *src;
 	off_t offset;
 	size_t size;
 	unsigned int prot;

tools/testing/selftests/sgx/sigstruct.c

@@ -289,14 +289,14 @@ static bool mrenclave_eextend(EVP_MD_CTX *ctx, uint64_t offset,
 static bool mrenclave_segment(EVP_MD_CTX *ctx, struct encl *encl,
 			      struct encl_segment *seg)
 {
-	uint64_t end = seg->offset + seg->size;
+	uint64_t end = seg->size;
 	uint64_t offset;
 
-	for (offset = seg->offset; offset < end; offset += PAGE_SIZE) {
-		if (!mrenclave_eadd(ctx, offset, seg->flags))
+	for (offset = 0; offset < end; offset += PAGE_SIZE) {
+		if (!mrenclave_eadd(ctx, seg->offset + offset, seg->flags))
 			return false;
 
-		if (!mrenclave_eextend(ctx, offset, encl->src + offset))
+		if (!mrenclave_eextend(ctx, seg->offset + offset, seg->src + offset))
 			return false;
 	}