diff options
Diffstat (limited to 'tools/testing/selftests/sgx/main.c')
-rw-r--r-- | tools/testing/selftests/sgx/main.c | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/tools/testing/selftests/sgx/main.c b/tools/testing/selftests/sgx/main.c index 61321229e485..1b4858f8ca4e 100644 --- a/tools/testing/selftests/sgx/main.c +++ b/tools/testing/selftests/sgx/main.c @@ -21,6 +21,7 @@ #include "main.h" static const uint64_t MAGIC = 0x1122334455667788ULL; +static const uint64_t MAGIC2 = 0x8877665544332211ULL; vdso_sgx_enter_enclave_t vdso_sgx_enter_enclave; struct vdso_symtab { @@ -107,6 +108,25 @@ static Elf64_Sym *vdso_symtab_get(struct vdso_symtab *symtab, const char *name) return NULL; } +/* + * Return the offset in the enclave where the data segment can be found. + * The first RW segment loaded is the TCS, skip that to get info on the + * data segment. + */ +static off_t encl_get_data_offset(struct encl *encl) +{ + int i; + + for (i = 1; i < encl->nr_segments; i++) { + struct encl_segment *seg = &encl->segment_tbl[i]; + + if (seg->prot == (PROT_READ | PROT_WRITE)) + return seg->offset; + } + + return -1; +} + FIXTURE(enclave) { struct encl encl; struct sgx_enclave_run run; @@ -389,4 +409,118 @@ TEST_F(enclave, clobbered_vdso_and_user_function) EXPECT_EQ(self->run.user_data, 0); } +/* + * Second page of .data segment is used to test changing PTE permissions. + * This spans the local encl_buffer within the test enclave. + * + * 1) Start with a sanity check: a value is written to the target page within + * the enclave and read back to ensure target page can be written to. + * 2) Change PTE permissions (RW -> RO) of target page within enclave. + * 3) Repeat (1) - this time expecting a regular #PF communicated via the + * vDSO. + * 4) Change PTE permissions of target page within enclave back to be RW. + * 5) Repeat (1) by resuming enclave, now expected to be possible to write to + * and read from target page within enclave. + */ +TEST_F(enclave, pte_permissions) +{ + struct encl_op_get_from_addr get_addr_op; + struct encl_op_put_to_addr put_addr_op; + unsigned long data_start; + int ret; + + ASSERT_TRUE(setup_test_encl(ENCL_HEAP_SIZE_DEFAULT, &self->encl, _metadata)); + + memset(&self->run, 0, sizeof(self->run)); + self->run.tcs = self->encl.encl_base; + + data_start = self->encl.encl_base + + encl_get_data_offset(&self->encl) + + PAGE_SIZE; + + /* + * Sanity check to ensure it is possible to write to page that will + * have its permissions manipulated. + */ + + /* Write MAGIC to page */ + put_addr_op.value = MAGIC; + put_addr_op.addr = data_start; + put_addr_op.header.type = ENCL_OP_PUT_TO_ADDRESS; + + EXPECT_EQ(ENCL_CALL(&put_addr_op, &self->run, true), 0); + + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + + /* + * Read memory that was just written to, confirming that it is the + * value previously written (MAGIC). + */ + get_addr_op.value = 0; + get_addr_op.addr = data_start; + get_addr_op.header.type = ENCL_OP_GET_FROM_ADDRESS; + + EXPECT_EQ(ENCL_CALL(&get_addr_op, &self->run, true), 0); + + EXPECT_EQ(get_addr_op.value, MAGIC); + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + + /* Change PTE permissions of target page within the enclave */ + ret = mprotect((void *)data_start, PAGE_SIZE, PROT_READ); + if (ret) + perror("mprotect"); + + /* + * PTE permissions of target page changed to read-only, EPCM + * permissions unchanged (EPCM permissions are RW), attempt to + * write to the page, expecting a regular #PF. + */ + + put_addr_op.value = MAGIC2; + + EXPECT_EQ(ENCL_CALL(&put_addr_op, &self->run, true), 0); + + EXPECT_EQ(self->run.exception_vector, 14); + EXPECT_EQ(self->run.exception_error_code, 0x7); + EXPECT_EQ(self->run.exception_addr, data_start); + + self->run.exception_vector = 0; + self->run.exception_error_code = 0; + self->run.exception_addr = 0; + + /* + * Change PTE permissions back to enable enclave to write to the + * target page and resume enclave - do not expect any exceptions this + * time. + */ + ret = mprotect((void *)data_start, PAGE_SIZE, PROT_READ | PROT_WRITE); + if (ret) + perror("mprotect"); + + EXPECT_EQ(vdso_sgx_enter_enclave((unsigned long)&put_addr_op, 0, + 0, ERESUME, 0, 0, &self->run), + 0); + + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); + + get_addr_op.value = 0; + + EXPECT_EQ(ENCL_CALL(&get_addr_op, &self->run, true), 0); + + EXPECT_EQ(get_addr_op.value, MAGIC2); + EXPECT_EEXIT(&self->run); + EXPECT_EQ(self->run.exception_vector, 0); + EXPECT_EQ(self->run.exception_error_code, 0); + EXPECT_EQ(self->run.exception_addr, 0); +} + TEST_HARNESS_MAIN |