/* Check if current instrumentation can be merged into previous aflags
* (or on ARM, GPR) save/restore inserted by drx_restore_arith_flags.
* Returns NULL if cannot merge. Otherwise, returns the right insertion point,
* i.e., DRX_NOTE_AFLAGS_RESTORE_BEGIN label instr.
*
* This routine looks for labels inserted by drx_restore_arith_flags,
* so changes to drx_restore_arith_flags may affect this routine.
* On ARM the labels are from drx_insert_counter_update.
*/
static instr_t *
merge_prev_drx_spill(instr_t *where, bool aflags)
{
instr_t *instr;
#ifdef DEBUG
bool has_sahf = false;
#endif
if (where == NULL)
return NULL;
instr = instr_get_prev(where);
if (instr == NULL)
return NULL;
if (!instr_is_label(instr))
return NULL;
/* Check if prev instr is DRX_NOTE_AFLAGS_RESTORE_END.
* We bail even there is only a label instr in between, which
* might be a target of internal cti.
*/
if (instr_get_note(instr) != NOTE_VAL(DRX_NOTE_AFLAGS_RESTORE_END))
return NULL;
/* find DRX_NOTE_AFLAGS_RESTORE_BEGIN */
for (instr = instr_get_prev(instr);
instr != NULL;
instr = instr_get_prev(instr)) {
if (instr_is_app(instr)) {
/* we do not expect any app instr */
ASSERT(false, "drx aflags restore is corrupted");
return NULL;
}
if (instr_is_label(instr)) {
if (instr_get_note(instr) == NOTE_VAL(DRX_NOTE_AFLAGS_RESTORE_BEGIN)) {
ASSERT(!aflags || has_sahf, "missing sahf");
return instr;
}
/* we do not expect any other label instr */
ASSERT(false, "drx aflags restore is corrupted");
return NULL;
#ifdef DEBUG
} else {
if (instr_get_note(instr) == NOTE_VAL(DRX_NOTE_AFLAGS_RESTORE_SAHF))
has_sahf = true;
#endif
}
}
return NULL;
}
static instr_t *
analyze_client_code(void *drcontext,
instrlist_t *ilist,
instr_t *where,
ref_info_t *ref_info)
{
instr_t *next, *lea, *and, *cmp, *jcc, *sub;
opnd_t ref, opnd;
ref_cache_t *cache;
reg_id_t reg;
int pos, i;
next = instr_get_next(where);
if (next == NULL)
return NULL;
if (instr_get_opcode(where) != OP_lea)
return next;
/* lea [ref] => r1 */
ref = instr_get_src(where, 0);
if (!opnd_is_base_disp(ref) || opnd_get_index(ref) != DR_REG_NULL)
return next;
lea = where;
and = next;
cmp = instr_get_next(and);
jcc = instr_get_next(cmp);
if (instr_get_app_pc(and) == NULL &&
instr_get_opcode(and) == OP_and &&
instr_get_app_pc(cmp) == NULL &&
instr_get_opcode(cmp) == OP_cmp &&
instr_get_app_pc(jcc) == NULL &&
instr_get_opcode(jcc) == OP_jz) {
/* find pattern of
* lea [ref] => reg
* and 0xffffffff00000000 reg
* cmp cache->tag reg
* jz
*/
opnd = instr_get_src(cmp, 1);
cache = opnd_get_addr(opnd) - offsetof(ref_cache_t, tag);
for (i = 0; i < 10; ) {
lea = instr_get_next(lea);
if (!instr_is_label(lea))
i++;
}
DR_ASSERT(instr_get_opcode(lea) == OP_lea);
} else if (instr_get_app_pc(next) == NULL &&
instr_get_opcode(next) == OP_sub) {
opnd = instr_get_src(next, 0);
cache = opnd_get_addr(opnd) - offsetof(ref_cache_t, offset);
} else {
return next;
}
reg = opnd_get_base(ref);
UMBRA_REG_TO_POS(reg, pos);
if (ref_info[pos].cache == NULL) {
ref_info[pos].cache = cache;
} else {
sub = instr_get_next(lea);
DR_ASSERT(instr_get_opcode(sub) == OP_sub);
while (lea != where) {
next = instr_get_next(where);
instrlist_remove(ilist, where);
instr_destroy(drcontext, where);
where = next;
}
opnd = OPND_CREATE_ABSMEM((void *)(reg_t)ref_info[pos].cache +
offsetof(ref_cache_t, offset),
OPSZ_PTR);
instr_set_src(sub, 0, opnd);
if (proc_info.client.app_unit_bits > 0 &&
proc_info.client.shd_unit_bits != 0)
next = instr_get_next(sub); /* reg & mask => reg */
if (proc_info.client.orig_addr) {
next = instr_get_next(next); /* mov reg => r2 */
next = instr_get_next(next); /* r2 & bit_mask => r2 */
}
}
next = instr_get_next(lea);
return instr_get_next(next);
}
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;
}
