static void
instrument_post_write(void *drcontext, instrlist_t *ilist, instr_t *where, opnd_t memref,
instr_t *write, reg_id_t reg_addr)
{
reg_id_t reg_ptr;
ushort stride = (ushort)drutil_opnd_mem_size_in_bytes(memref, write);
/* We want to use the same predicate as write when inserting the following
* instrumentation.
*/
instrlist_set_auto_predicate(ilist, instr_get_predicate(write));
if (drreg_reserve_register(drcontext, ilist, where, NULL, ®_ptr) !=
DRREG_SUCCESS) {
DR_ASSERT(false);
return;
}
drx_buf_insert_load_buf_ptr(drcontext, write_buffer, ilist, where, reg_ptr);
/* drx_buf_insert_buf_memcpy() internally updates the buffer pointer */
drx_buf_insert_buf_memcpy(drcontext, write_buffer, ilist, where, reg_ptr, reg_addr,
stride);
if (drreg_unreserve_register(drcontext, ilist, where, reg_ptr) != DRREG_SUCCESS)
DR_ASSERT(false);
if (drreg_unreserve_register(drcontext, ilist, where, reg_addr) != DRREG_SUCCESS)
DR_ASSERT(false);
/* Set the predicate back to the default */
instrlist_set_auto_predicate(ilist, instr_get_predicate(where));
}
static dr_emit_flags_t
event_app_instruction(void *drcontext, void *tag, instrlist_t *bb, instr_t *inst,
bool for_trace, bool translating, void *user_data)
{
reg_id_t reg_ptr = IF_X86_ELSE(DR_REG_XDX, TEST_REG);
reg_id_t reg_tmp = IF_X86_ELSE(DR_REG_XCX, DR_REG_R3);
/* We need a third register on ARM, because updating the buf pointer
* requires a second scratch reg.
*/
reg_id_t scratch = IF_X86_ELSE(reg_tmp, DR_REG_R5);
ptr_int_t subtest = (ptr_int_t) user_data;
if (!instr_is_label(inst))
return DR_EMIT_DEFAULT;
#ifdef X86
scratch = reg_resize_to_opsz(scratch, OPSZ_4);
#endif
if (subtest == DRX_BUF_TEST_1_C) {
/* testing fast circular buffer */
/* test to make sure that on first invocation, the buffer is empty */
dr_insert_clean_call(drcontext, bb, inst, verify_buffers_empty, false, 1,
OPND_CREATE_INTPTR(circular_fast));
/* load the buf pointer, and then write a garbage element to the buffer */
drx_buf_insert_load_buf_ptr(drcontext, circular_fast, bb, inst, reg_ptr);
drx_buf_insert_buf_store(drcontext, circular_fast, bb, inst, reg_ptr,
DR_REG_NULL, opnd_create_reg(scratch), OPSZ_4, 0);
drx_buf_insert_update_buf_ptr(drcontext, circular_fast, bb, inst, reg_ptr,
reg_tmp, sizeof(int));
/* verify the buffer was written to */
dr_insert_clean_call(drcontext, bb, inst, verify_buffers_dirty, false, 2,
OPND_CREATE_INTPTR(circular_fast),
opnd_create_reg(scratch));
/* fast circular buffer: trigger an overflow */
drx_buf_insert_load_buf_ptr(drcontext, circular_fast, bb, inst, reg_ptr);
drx_buf_insert_update_buf_ptr(drcontext, circular_fast, bb, inst, reg_ptr,
reg_tmp, CIRCULAR_FAST_SZ - sizeof(int));
/* the buffer is now clean */
dr_insert_clean_call(drcontext, bb, inst, verify_buffers_empty, false, 1,
OPND_CREATE_INTPTR(circular_fast));
} else if (subtest == DRX_BUF_TEST_2_C) {
/* testing slow circular buffer */
/* test to make sure that on first invocation, the buffer is empty */
dr_insert_clean_call(drcontext, bb, inst, verify_buffers_empty, false, 1,
OPND_CREATE_INTPTR(circular_slow));
/* load the buf pointer, and then write an element to the buffer */
drx_buf_insert_load_buf_ptr(drcontext, circular_slow, bb, inst, reg_ptr);
drx_buf_insert_buf_store(drcontext, circular_fast, bb, inst, reg_ptr,
DR_REG_NULL, opnd_create_reg(scratch), OPSZ_4, 0);
drx_buf_insert_update_buf_ptr(drcontext, circular_slow, bb, inst, reg_ptr,
DR_REG_NULL, sizeof(int));
/* verify the buffer was written to */
dr_insert_clean_call(drcontext, bb, inst, verify_buffers_dirty, false, 2,
OPND_CREATE_INTPTR(circular_slow),
opnd_create_reg(scratch));
/* slow circular buffer: trigger a fault */
drx_buf_insert_load_buf_ptr(drcontext, circular_slow, bb, inst, reg_ptr);
drx_buf_insert_update_buf_ptr(drcontext, circular_slow, bb, inst, reg_ptr,
DR_REG_NULL, CIRCULAR_SLOW_SZ - sizeof(int));
/* the "trigger" is a write, so we write whatever garbage is in reg_tmp */
drx_buf_insert_buf_store(drcontext, circular_fast, bb, inst, reg_ptr,
DR_REG_NULL, opnd_create_reg(scratch), OPSZ_4, 0);
/* the buffer is now clean */
dr_insert_clean_call(drcontext, bb, inst, verify_buffers_empty, false, 1,
OPND_CREATE_INTPTR(circular_slow));
} else if (subtest == DRX_BUF_TEST_3_C) {
/* testing trace buffer */
/* test to make sure that on first invocation, the buffer is empty */
dr_insert_clean_call(drcontext, bb, inst, verify_buffers_empty, false, 1,
OPND_CREATE_INTPTR(trace));
/* load the buf pointer, and then write an element to the buffer */
drx_buf_insert_load_buf_ptr(drcontext, trace, bb, inst, reg_ptr);
drx_buf_insert_buf_store(drcontext, circular_fast, bb, inst, reg_ptr,
DR_REG_NULL, opnd_create_reg(scratch), OPSZ_4, 0);
drx_buf_insert_update_buf_ptr(drcontext, trace, bb, inst, reg_ptr,
DR_REG_NULL, sizeof(int));
/* verify the buffer was written to */
dr_insert_clean_call(drcontext, bb, inst, verify_buffers_dirty, false, 2,
OPND_CREATE_INTPTR(trace),
opnd_create_reg(scratch));
/* trace buffer: trigger a fault and verify */
drx_buf_insert_load_buf_ptr(drcontext, trace, bb, inst, reg_ptr);
drx_buf_insert_update_buf_ptr(drcontext, trace, bb, inst, reg_ptr,
DR_REG_NULL, TRACE_SZ - sizeof(int));
/* the "trigger" is a write, so we write whatever garbage is in reg_tmp */
drx_buf_insert_buf_store(drcontext, circular_fast, bb, inst, reg_ptr,
DR_REG_NULL, opnd_create_reg(scratch), OPSZ_4, 0);
/* the buffer is now clean */
dr_insert_clean_call(drcontext, bb, inst, verify_buffers_empty, false, 1,
OPND_CREATE_INTPTR(trace));
} else if (subtest == DRX_BUF_TEST_4_C) {
/* test immediate store: 8 bytes (if possible), 4 bytes, 2 bytes and 1 byte */
/* "ABCDEFGH\x00" (x2 for x64) */
drx_buf_insert_load_buf_ptr(drcontext, circular_fast, bb, inst, reg_ptr);
drx_buf_insert_buf_store(drcontext, circular_fast, bb, inst, reg_ptr,
scratch, opnd_create_immed_int(0x41, OPSZ_1),
OPSZ_1, 0);
drx_buf_insert_buf_store(drcontext, circular_fast, bb, inst, reg_ptr,
scratch, opnd_create_immed_int(0x42, OPSZ_1),
OPSZ_1, 1);
drx_buf_insert_buf_store(drcontext, circular_fast, bb, inst, reg_ptr,
scratch, opnd_create_immed_int(0x4443, OPSZ_2),
OPSZ_2, 2);
drx_buf_insert_buf_store(drcontext, circular_fast, bb, inst, reg_ptr,
scratch, opnd_create_immed_int(0x48474645, OPSZ_4),
OPSZ_4, 4);
#ifdef X64
drx_buf_insert_buf_store(drcontext, circular_fast, bb, inst, reg_ptr,
scratch, opnd_create_immed_int(0x4847464544434241,
OPSZ_8),
OPSZ_8, 8);
drx_buf_insert_buf_store(drcontext, circular_fast, bb, inst, reg_ptr,
scratch, opnd_create_immed_int(0x00, OPSZ_1),
OPSZ_1, 17);
#else
drx_buf_insert_buf_store(drcontext, circular_fast, bb, inst, reg_ptr,
scratch, opnd_create_immed_int(0x00, OPSZ_1),
OPSZ_1, 9);
#endif
dr_insert_clean_call(drcontext, bb, inst, verify_store, false, 1,
OPND_CREATE_INTPTR(circular_fast));
} else if (subtest == DRX_BUF_TEST_5_C) {
/* test register store: 8 bytes (if possible), 4 bytes, 2 bytes and 1 byte */
/* "ABCDEFGH\x00" (x2 for x64) */
drx_buf_insert_load_buf_ptr(drcontext, circular_fast, bb, inst, reg_ptr);
scratch = reg_resize_to_opsz(scratch, OPSZ_1);
MINSERT(bb, inst, XINST_CREATE_load_int
(drcontext,
opnd_create_reg(scratch),
opnd_create_immed_int(0x41, OPSZ_1)));
drx_buf_insert_buf_store(drcontext, circular_fast, bb, inst, reg_ptr,
DR_REG_NULL, opnd_create_reg(scratch),
OPSZ_1, 0);
MINSERT(bb, inst, XINST_CREATE_load_int
(drcontext,
opnd_create_reg(scratch),
opnd_create_immed_int(0x42, OPSZ_1)));
drx_buf_insert_buf_store(drcontext, circular_fast, bb, inst, reg_ptr,
DR_REG_NULL, opnd_create_reg(scratch),
OPSZ_1, 1);
scratch = reg_resize_to_opsz(scratch, OPSZ_2);
MINSERT(bb, inst, XINST_CREATE_load_int
(drcontext,
opnd_create_reg(scratch),
opnd_create_immed_int(0x4443, OPSZ_2)));
drx_buf_insert_buf_store(drcontext, circular_fast, bb, inst, reg_ptr,
DR_REG_NULL, opnd_create_reg(scratch),
OPSZ_2, 2);
scratch = reg_resize_to_opsz(scratch, OPSZ_4);
#ifdef X86
MINSERT(bb, inst, XINST_CREATE_load_int
(drcontext,
opnd_create_reg(scratch),
opnd_create_immed_int(0x48474645, OPSZ_4)));
#else
instrlist_insert_mov_immed_ptrsz(drcontext, 0x48474645,
opnd_create_reg(reg_resize_to_opsz
(scratch, OPSZ_PTR)),
bb, inst, NULL, NULL);
#endif
drx_buf_insert_buf_store(drcontext, circular_fast, bb, inst, reg_ptr,
DR_REG_NULL, opnd_create_reg(scratch),
OPSZ_4, 4);
#ifdef X64
scratch = reg_resize_to_opsz(scratch, OPSZ_8);
/* only way to reliably move a 64 bit int into a register */
instrlist_insert_mov_immed_ptrsz(drcontext, 0x4847464544434241,
opnd_create_reg(scratch),
bb, inst, NULL, NULL);
drx_buf_insert_buf_store(drcontext, circular_fast, bb, inst, reg_ptr,
DR_REG_NULL, opnd_create_reg(scratch),
OPSZ_8, 8);
drx_buf_insert_buf_store(drcontext, circular_fast, bb, inst, reg_ptr,
scratch, opnd_create_immed_int(0x00, OPSZ_1),
OPSZ_1, 17);
#else
drx_buf_insert_buf_store(drcontext, circular_fast, bb, inst, reg_ptr,
scratch, opnd_create_immed_int(0x00, OPSZ_1),
OPSZ_1, 9);
#endif
dr_insert_clean_call(drcontext, bb, inst, verify_store, false, 1,
OPND_CREATE_INTPTR(circular_fast));
} else if (subtest == DRX_BUF_TEST_6_C) {
/* Currently, the fast circular buffer does not recommend variable-size
* writes, for good reason. We don't test the memcpy operation on the
* fast circular buffer.
*/
/* verify memcpy works on the slow clrcular buffer */
drx_buf_insert_load_buf_ptr(drcontext, circular_slow, bb, inst, reg_ptr);
instrlist_insert_mov_immed_ptrsz(drcontext, (ptr_int_t)test_copy,
opnd_create_reg(reg_resize_to_opsz
(scratch, OPSZ_PTR)),
bb, inst, NULL, NULL);
drx_buf_insert_buf_memcpy(drcontext, circular_slow, bb, inst,
reg_ptr, reg_resize_to_opsz(scratch, OPSZ_PTR),
sizeof(test_copy));
/* NULL out the buffer */
drx_buf_insert_load_buf_ptr(drcontext, circular_slow, bb, inst, reg_ptr);
instrlist_insert_mov_immed_ptrsz(drcontext, (ptr_int_t)test_null,
opnd_create_reg(reg_resize_to_opsz
(scratch, OPSZ_PTR)),
bb, inst, NULL, NULL);
drx_buf_insert_buf_memcpy(drcontext, circular_slow, bb, inst,
reg_ptr, reg_resize_to_opsz(scratch, OPSZ_PTR),
sizeof(test_null));
/* Unfortunately, we can't just use the check in verify_buffer_empty, because
* drx_buf_insert_buf_memcpy() incrememnts the buffer pointer internally, unlike
* drx_buf_insert_buf_store(). We simply check that the buffer was NULLed out.
*/
dr_insert_clean_call(drcontext, bb, inst, (void *)verify_buffers_nulled, false, 1,
OPND_CREATE_INTPTR(circular_slow));
/* verify memcpy works on the trace buffer */
drx_buf_insert_load_buf_ptr(drcontext, trace, bb, inst, reg_ptr);
instrlist_insert_mov_immed_ptrsz(drcontext, (ptr_int_t)test_copy,
opnd_create_reg(reg_resize_to_opsz
(scratch, OPSZ_PTR)),
bb, inst, NULL, NULL);
drx_buf_insert_buf_memcpy(drcontext, trace, bb, inst,
reg_ptr, reg_resize_to_opsz(scratch, OPSZ_PTR),
sizeof(test_copy));
/* NULL out the buffer */
drx_buf_insert_load_buf_ptr(drcontext, trace, bb, inst, reg_ptr);
instrlist_insert_mov_immed_ptrsz(drcontext, (ptr_int_t)test_null,
opnd_create_reg(reg_resize_to_opsz
(scratch, OPSZ_PTR)),
bb, inst, NULL, NULL);
drx_buf_insert_buf_memcpy(drcontext, trace, bb, inst,
reg_ptr, reg_resize_to_opsz(scratch, OPSZ_PTR),
sizeof(test_null));
/* verify buffer was NULLed */
dr_insert_clean_call(drcontext, bb, inst, (void *)verify_buffers_nulled, false, 1,
OPND_CREATE_INTPTR(trace));
}
return DR_EMIT_DEFAULT;
}