diff options
Diffstat (limited to 'tools/testing/selftests/sgx/test_encl.c')
-rw-r--r-- | tools/testing/selftests/sgx/test_encl.c | 67 |
1 files changed, 45 insertions, 22 deletions
diff --git a/tools/testing/selftests/sgx/test_encl.c b/tools/testing/selftests/sgx/test_encl.c index c0d6397295e3..2c4d709cce2d 100644 --- a/tools/testing/selftests/sgx/test_encl.c +++ b/tools/testing/selftests/sgx/test_encl.c @@ -5,11 +5,12 @@ #include "defines.h" /* - * Data buffer spanning two pages that will be placed first in .data - * segment. Even if not used internally the second page is needed by - * external test manipulating page permissions. + * Data buffer spanning two pages that will be placed first in the .data + * segment via the linker script. Even if not used internally the second page + * is needed by external test manipulating page permissions, so mark + * encl_buffer as "used" to make sure it is entirely preserved by the compiler. */ -static uint8_t encl_buffer[8192] = { 1 }; +static uint8_t __used __section(".data.encl_buffer") encl_buffer[8192] = { 1 }; enum sgx_enclu_function { EACCEPT = 0x5, @@ -24,10 +25,11 @@ static void do_encl_emodpe(void *_op) secinfo.flags = op->flags; asm volatile(".byte 0x0f, 0x01, 0xd7" - : + : /* no outputs */ : "a" (EMODPE), "b" (&secinfo), - "c" (op->epc_addr)); + "c" (op->epc_addr) + : "memory" /* read from secinfo pointer */); } static void do_encl_eaccept(void *_op) @@ -42,7 +44,8 @@ static void do_encl_eaccept(void *_op) : "=a" (rax) : "a" (EACCEPT), "b" (&secinfo), - "c" (op->epc_addr)); + "c" (op->epc_addr) + : "memory" /* read from secinfo pointer */); op->ret = rax; } @@ -119,21 +122,41 @@ static void do_encl_op_nop(void *_op) } +/* + * Symbol placed at the start of the enclave image by the linker script. + * Declare this extern symbol with visibility "hidden" to ensure the compiler + * does not access it through the GOT and generates position-independent + * addressing as __encl_base(%rip), so we can get the actual enclave base + * during runtime. + */ +extern const uint8_t __attribute__((visibility("hidden"))) __encl_base; + +typedef void (*encl_op_t)(void *); +static const encl_op_t encl_op_array[ENCL_OP_MAX] = { + do_encl_op_put_to_buf, + do_encl_op_get_from_buf, + do_encl_op_put_to_addr, + do_encl_op_get_from_addr, + do_encl_op_nop, + do_encl_eaccept, + do_encl_emodpe, + do_encl_init_tcs_page, +}; + void encl_body(void *rdi, void *rsi) { - const void (*encl_op_array[ENCL_OP_MAX])(void *) = { - do_encl_op_put_to_buf, - do_encl_op_get_from_buf, - do_encl_op_put_to_addr, - do_encl_op_get_from_addr, - do_encl_op_nop, - do_encl_eaccept, - do_encl_emodpe, - do_encl_init_tcs_page, - }; - - struct encl_op_header *op = (struct encl_op_header *)rdi; - - if (op->type < ENCL_OP_MAX) - (*encl_op_array[op->type])(op); + struct encl_op_header *header = (struct encl_op_header *)rdi; + encl_op_t op; + + if (header->type >= ENCL_OP_MAX) + return; + + /* + * The enclave base address needs to be added, as this call site + * *cannot be* made rip-relative by the compiler, or fixed up by + * any other possible means. + */ + op = ((uint64_t)&__encl_base) + encl_op_array[header->type]; + + (*op)(header); } |