From: Jarkko Sakkinen <jarkko@kernel.org>
To: linux-sgx@vger.kernel.org
Cc: Nathaniel McCallum <nathaniel@profian.com>,
Reinette Chatre <reinette.chatre@intel.com>,
Jarkko Sakkinen <jarkko@kernel.org>,
Dave Hansen <dave.hansen@linux.intel.com>,
Shuah Khan <shuah@kernel.org>,
linux-kselftest@vger.kernel.org (open list:KERNEL SELFTEST
FRAMEWORK), linux-kernel@vger.kernel.org (open list)
Subject: [RFC PATCH v2.1 19/30] selftests/sgx: Test two different SGX2 EAUG flows
Date: Fri, 4 Mar 2022 11:35:13 +0200 [thread overview]
Message-ID: <20220304093524.397485-19-jarkko@kernel.org> (raw)
In-Reply-To: <20220304093524.397485-1-jarkko@kernel.org>
From: Reinette Chatre <reinette.chatre@intel.com>
Enclave pages can be added to an initialized enclave when an address
belonging to the enclave but without a backing page is accessed from
within the enclave.
Accessing memory without a backing enclave page from within an enclave
can be in different ways:
1) Pre-emptively run ENCLU[EACCEPT]. Since the addition of a page
always needs to be accepted by the enclave via ENCLU[EACCEPT] this
flow is efficient since the first execution of ENCLU[EACCEPT]
triggers the addition of the page and when execution returns to the
same instruction the second execution would be successful as an
acceptance of the page.
2) A direct read or write. The flow where a direct read or write
triggers the page addition execution cannot resume from the
instruction (read/write) that triggered the fault but instead
the enclave needs to be entered at a different entry point to
run needed ENCLU[EACCEPT] before execution can return to the
original entry point and the read/write instruction that faulted.
Add tests for both flows.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
---
tools/testing/selftests/sgx/main.c | 243 +++++++++++++++++++++++++++++
1 file changed, 243 insertions(+)
diff --git a/tools/testing/selftests/sgx/main.c b/tools/testing/selftests/sgx/main.c
index ea5f2e064687..13542c5de66f 100644
--- a/tools/testing/selftests/sgx/main.c
+++ b/tools/testing/selftests/sgx/main.c
@@ -86,6 +86,15 @@ static bool vdso_get_symtab(void *addr, struct vdso_symtab *symtab)
return true;
}
+static inline int sgx2_supported(void)
+{
+ unsigned int eax, ebx, ecx, edx;
+
+ __cpuid_count(SGX_CPUID, 0x0, eax, ebx, ecx, edx);
+
+ return eax & 0x2;
+}
+
static unsigned long elf_sym_hash(const char *name)
{
unsigned long h = 0, high;
@@ -863,4 +872,238 @@ TEST_F(enclave, epcm_permissions)
EXPECT_EQ(self->run.exception_addr, 0);
}
+/*
+ * Test the addition of pages to an initialized enclave via writing to
+ * a page belonging to the enclave's address space but was not added
+ * during enclave creation.
+ */
+TEST_F(enclave, augment)
+{
+ struct encl_op_get_from_addr get_addr_op;
+ struct encl_op_put_to_addr put_addr_op;
+ struct encl_op_eaccept eaccept_op;
+ size_t total_size = 0;
+ void *addr;
+ int i;
+
+ if (!sgx2_supported())
+ SKIP(return, "SGX2 not supported");
+
+ 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;
+
+ for (i = 0; i < self->encl.nr_segments; i++) {
+ struct encl_segment *seg = &self->encl.segment_tbl[i];
+
+ total_size += seg->size;
+ }
+
+ /*
+ * Actual enclave size is expected to be larger than the loaded
+ * test enclave since enclave size must be a power of 2 in bytes
+ * and test_encl does not consume it all.
+ */
+ EXPECT_LT(total_size + PAGE_SIZE, self->encl.encl_size);
+
+ /*
+ * Create memory mapping for the page that will be added. New
+ * memory mapping is for one page right after all existing
+ * mappings.
+ */
+ addr = mmap((void *)self->encl.encl_base + total_size, PAGE_SIZE,
+ PROT_READ | PROT_WRITE | PROT_EXEC,
+ MAP_SHARED | MAP_FIXED, self->encl.fd, 0);
+ EXPECT_NE(addr, MAP_FAILED);
+
+ self->run.exception_vector = 0;
+ self->run.exception_error_code = 0;
+ self->run.exception_addr = 0;
+
+ /*
+ * Attempt to write to the new page from within enclave.
+ * Expected to fail since page is not (yet) part of the enclave.
+ * The first #PF will trigger the addition of the page to the
+ * enclave, but since the new page needs an EACCEPT from within the
+ * enclave before it can be used it would not be possible
+ * to successfully return to the failing instruction. This is the
+ * cause of the second #PF captured here having the SGX bit set,
+ * it is from hardware preventing the page from being used.
+ */
+ put_addr_op.value = MAGIC;
+ put_addr_op.addr = (unsigned long)addr;
+ put_addr_op.header.type = ENCL_OP_PUT_TO_ADDRESS;
+
+ EXPECT_EQ(ENCL_CALL(&put_addr_op, &self->run, true), 0);
+
+ EXPECT_EQ(self->run.function, ERESUME);
+ EXPECT_EQ(self->run.exception_vector, 14);
+ EXPECT_EQ(self->run.exception_addr, (unsigned long)addr);
+
+ if (self->run.exception_error_code == 0x6) {
+ munmap(addr, PAGE_SIZE);
+ SKIP(return, "Kernel does not support adding pages to initialized enclave");
+ }
+
+ EXPECT_EQ(self->run.exception_error_code, 0x8007);
+
+ self->run.exception_vector = 0;
+ self->run.exception_error_code = 0;
+ self->run.exception_addr = 0;
+
+ /* Handle AEX by running EACCEPT from new entry point. */
+ self->run.tcs = self->encl.encl_base + PAGE_SIZE;
+
+ eaccept_op.epc_addr = self->encl.encl_base + total_size;
+ eaccept_op.flags = SGX_SECINFO_R | SGX_SECINFO_W | SGX_SECINFO_REG | SGX_SECINFO_PENDING;
+ eaccept_op.ret = 0;
+ eaccept_op.header.type = ENCL_OP_EACCEPT;
+
+ EXPECT_EQ(ENCL_CALL(&eaccept_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);
+ EXPECT_EQ(eaccept_op.ret, 0);
+
+ /* Can now return to main TCS to resume execution. */
+ self->run.tcs = self->encl.encl_base;
+
+ 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);
+
+ /*
+ * Read memory from newly added page that was just written to,
+ * confirming that data previously written (MAGIC) is present.
+ */
+ get_addr_op.value = 0;
+ get_addr_op.addr = (unsigned long)addr;
+ 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);
+
+ munmap(addr, PAGE_SIZE);
+}
+
+/*
+ * Test for the addition of pages to an initialized enclave via a
+ * pre-emptive run of EACCEPT on page to be added.
+ */
+TEST_F(enclave, augment_via_eaccept)
+{
+ struct encl_op_get_from_addr get_addr_op;
+ struct encl_op_put_to_addr put_addr_op;
+ struct encl_op_eaccept eaccept_op;
+ size_t total_size = 0;
+ void *addr;
+ int i;
+
+ if (!sgx2_supported())
+ SKIP(return, "SGX2 not supported");
+
+ 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;
+
+ for (i = 0; i < self->encl.nr_segments; i++) {
+ struct encl_segment *seg = &self->encl.segment_tbl[i];
+
+ total_size += seg->size;
+ }
+
+ /*
+ * Actual enclave size is expected to be larger than the loaded
+ * test enclave since enclave size must be a power of 2 in bytes while
+ * test_encl does not consume it all.
+ */
+ EXPECT_LT(total_size + PAGE_SIZE, self->encl.encl_size);
+
+ /*
+ * mmap() a page at end of existing enclave to be used for dynamic
+ * EPC page.
+ */
+
+ addr = mmap((void *)self->encl.encl_base + total_size, PAGE_SIZE,
+ PROT_READ | PROT_WRITE | PROT_EXEC, MAP_SHARED | MAP_FIXED,
+ self->encl.fd, 0);
+ EXPECT_NE(addr, MAP_FAILED);
+
+ self->run.exception_vector = 0;
+ self->run.exception_error_code = 0;
+ self->run.exception_addr = 0;
+
+ /*
+ * Run EACCEPT on new page to trigger the #PF->EAUG->EACCEPT(again
+ * without a #PF). All should be transparent to userspace.
+ */
+ eaccept_op.epc_addr = self->encl.encl_base + total_size;
+ eaccept_op.flags = SGX_SECINFO_R | SGX_SECINFO_W | SGX_SECINFO_REG | SGX_SECINFO_PENDING;
+ eaccept_op.ret = 0;
+ eaccept_op.header.type = ENCL_OP_EACCEPT;
+
+ EXPECT_EQ(ENCL_CALL(&eaccept_op, &self->run, true), 0);
+
+ if (self->run.exception_vector == 14 &&
+ self->run.exception_error_code == 4 &&
+ self->run.exception_addr == self->encl.encl_base + total_size) {
+ munmap(addr, PAGE_SIZE);
+ SKIP(return, "Kernel does not support adding pages to initialized enclave");
+ }
+
+ 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);
+ EXPECT_EQ(eaccept_op.ret, 0);
+
+ /*
+ * New page should be accessible from within enclave - attempt to
+ * write to it.
+ */
+ put_addr_op.value = MAGIC;
+ put_addr_op.addr = (unsigned long)addr;
+ 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 from newly added page that was just written to,
+ * confirming that data previously written (MAGIC) is present.
+ */
+ get_addr_op.value = 0;
+ get_addr_op.addr = (unsigned long)addr;
+ 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);
+
+ munmap(addr, PAGE_SIZE);
+}
+
TEST_HARNESS_MAIN
--
2.35.1
next prev parent reply other threads:[~2022-03-04 9:38 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-04 9:34 [RFC PATCH v2.1 01/30] x86/sgx: Add short descriptions to ENCLS wrappers Jarkko Sakkinen
2022-03-04 9:34 ` [RFC PATCH v2.1 02/30] x86/sgx: Add wrapper for SGX2 EMODPR function Jarkko Sakkinen
2022-03-04 9:34 ` [RFC PATCH v2.1 03/30] x86/sgx: Add wrapper for SGX2 EMODT function Jarkko Sakkinen
2022-03-04 9:34 ` [RFC PATCH v2.1 04/30] x86/sgx: Add wrapper for SGX2 EAUG function Jarkko Sakkinen
2022-03-04 9:34 ` [RFC PATCH v2.1 05/30] Documentation/x86: Document SGX permission details Jarkko Sakkinen
2022-03-04 9:35 ` [RFC PATCH v2.1 06/30] x86/sgx: Support VMA permissions more relaxed than enclave permissions Jarkko Sakkinen
2022-03-04 9:35 ` [RFC PATCH v2.1 07/30] x86/sgx: Add pfn_mkwrite() handler for present PTEs Jarkko Sakkinen
2022-03-04 9:35 ` [RFC PATCH v2.1 08/30] x86/sgx: Export sgx_encl_ewb_cpumask() Jarkko Sakkinen
2022-03-04 9:35 ` [RFC PATCH v2.1 09/30] x86/sgx: Rename sgx_encl_ewb_cpumask() as sgx_encl_cpumask() Jarkko Sakkinen
2022-03-04 9:35 ` [RFC PATCH v2.1 10/30] x86/sgx: Move PTE zap code to new sgx_zap_enclave_ptes() Jarkko Sakkinen
2022-03-04 9:35 ` [RFC PATCH v2.1 11/30] x86/sgx: Make sgx_ipi_cb() available internally Jarkko Sakkinen
2022-03-04 9:35 ` [RFC PATCH v2.1 12/30] x86/sgx: Create utility to validate user provided offset and length Jarkko Sakkinen
2022-03-04 9:35 ` [RFC PATCH v2.1 13/30] x86/sgx: Keep record of SGX page type Jarkko Sakkinen
2022-03-04 9:35 ` [RFC PATCH v2.1 14/30] x86/sgx: Support restricting of enclave page permissions Jarkko Sakkinen
2022-03-09 8:52 ` Jarkko Sakkinen
2022-03-09 9:35 ` Jarkko Sakkinen
2022-03-09 16:59 ` Reinette Chatre
2022-03-09 19:10 ` Reinette Chatre
2022-03-09 23:35 ` Jarkko Sakkinen
2022-03-09 23:42 ` Jarkko Sakkinen
2022-03-10 0:11 ` Reinette Chatre
2022-03-10 0:10 ` Reinette Chatre
2022-03-10 2:02 ` Jarkko Sakkinen
2022-03-04 9:35 ` [RFC PATCH v2.1 15/30] selftests/sgx: Add test for EPCM permission changes Jarkko Sakkinen
2022-03-04 9:35 ` [RFC PATCH v2.1 16/30] selftests/sgx: Add test for TCS page " Jarkko Sakkinen
2022-03-04 9:35 ` [RFC PATCH v2.1 17/30] x86/sgx: Support adding of pages to an initialized enclave Jarkko Sakkinen
2022-03-04 9:35 ` [RFC PATCH v2.1 18/30] x86/sgx: Tighten accessible memory range after enclave initialization Jarkko Sakkinen
2022-03-04 9:35 ` Jarkko Sakkinen [this message]
2022-03-04 9:35 ` [RFC PATCH v2.1 20/30] x86/sgx: Support modifying SGX page type Jarkko Sakkinen
2022-03-04 9:35 ` [RFC PATCH v2.1 21/30] x86/sgx: Support complete page removal Jarkko Sakkinen
2022-03-04 9:35 ` [RFC PATCH v2.1 22/30] Documentation/x86: Introduce enclave runtime management section Jarkko Sakkinen
2022-03-04 9:35 ` [RFC PATCH v2.1 23/30] selftests/sgx: Introduce dynamic entry point Jarkko Sakkinen
2022-03-04 9:35 ` [RFC PATCH v2.1 24/30] selftests/sgx: Introduce TCS initialization enclave operation Jarkko Sakkinen
2022-03-04 9:35 ` [RFC PATCH v2.1 25/30] selftests/sgx: Test complete changing of page type flow Jarkko Sakkinen
2022-03-04 9:35 ` [RFC PATCH v2.1 26/30] selftests/sgx: Test faulty enclave behavior Jarkko Sakkinen
2022-03-04 9:35 ` [RFC PATCH v2.1 27/30] selftests/sgx: Test invalid access to removed enclave page Jarkko Sakkinen
2022-03-04 9:35 ` [RFC PATCH v2.1 28/30] selftests/sgx: Test reclaiming of untouched page Jarkko Sakkinen
2022-03-04 9:35 ` [RFC PATCH v2.1 29/30] x86/sgx: Free up EPC pages directly to support large page ranges Jarkko Sakkinen
2022-03-04 9:35 ` [RFC PATCH v2.1 30/30] selftests/sgx: Page removal stress test Jarkko Sakkinen
2022-03-04 9:40 ` [RFC PATCH v2.1 01/30] x86/sgx: Add short descriptions to ENCLS wrappers Jarkko Sakkinen
2022-03-04 9:41 ` Jarkko Sakkinen
2022-03-14 19:04 ` Dave Hansen
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