linux-loongson/tools/perf/arch/x86/annotate/instructions.c
Namhyung Kim f4dc5a3355 perf annotate-data: Handle direct use of stack pointer without fbreg
Sometimes compiler generates code to use the stack pointer register
without frame pointer.  As we know RSP is the stack register on x86,
let's treat it as same as fbreg.  But the offset would be opposite
direction so update the debug message accordingly.

Reported-by: Blake Jones <blakejones@google.com>
Link: https://lore.kernel.org/r/20250126210242.1181225-1-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2025-02-26 13:42:49 -08:00

609 lines
17 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* x86 instruction nmemonic table to parse disasm lines for annotate.
* This table is searched twice - one for exact match and another for
* match without a size suffix (b, w, l, q) in case of AT&T syntax.
*
* So this table should not have entries with the suffix unless it's
* a complete different instruction than ones without the suffix.
*/
static struct ins x86__instructions[] = {
{ .name = "adc", .ops = &mov_ops, },
{ .name = "add", .ops = &mov_ops, },
{ .name = "addsd", .ops = &mov_ops, },
{ .name = "and", .ops = &mov_ops, },
{ .name = "andpd", .ops = &mov_ops, },
{ .name = "andps", .ops = &mov_ops, },
{ .name = "bsr", .ops = &mov_ops, },
{ .name = "bt", .ops = &mov_ops, },
{ .name = "btr", .ops = &mov_ops, },
{ .name = "bts", .ops = &mov_ops, },
{ .name = "call", .ops = &call_ops, },
{ .name = "cmovbe", .ops = &mov_ops, },
{ .name = "cmove", .ops = &mov_ops, },
{ .name = "cmovae", .ops = &mov_ops, },
{ .name = "cmp", .ops = &mov_ops, },
{ .name = "cmpxch", .ops = &mov_ops, },
{ .name = "cmpxchg", .ops = &mov_ops, },
{ .name = "cs", .ops = &mov_ops, },
{ .name = "dec", .ops = &dec_ops, },
{ .name = "divsd", .ops = &mov_ops, },
{ .name = "divss", .ops = &mov_ops, },
{ .name = "gs", .ops = &mov_ops, },
{ .name = "imul", .ops = &mov_ops, },
{ .name = "inc", .ops = &dec_ops, },
{ .name = "ja", .ops = &jump_ops, },
{ .name = "jae", .ops = &jump_ops, },
{ .name = "jb", .ops = &jump_ops, },
{ .name = "jbe", .ops = &jump_ops, },
{ .name = "jc", .ops = &jump_ops, },
{ .name = "jcxz", .ops = &jump_ops, },
{ .name = "je", .ops = &jump_ops, },
{ .name = "jecxz", .ops = &jump_ops, },
{ .name = "jg", .ops = &jump_ops, },
{ .name = "jge", .ops = &jump_ops, },
{ .name = "jl", .ops = &jump_ops, },
{ .name = "jle", .ops = &jump_ops, },
{ .name = "jmp", .ops = &jump_ops, },
{ .name = "jna", .ops = &jump_ops, },
{ .name = "jnae", .ops = &jump_ops, },
{ .name = "jnb", .ops = &jump_ops, },
{ .name = "jnbe", .ops = &jump_ops, },
{ .name = "jnc", .ops = &jump_ops, },
{ .name = "jne", .ops = &jump_ops, },
{ .name = "jng", .ops = &jump_ops, },
{ .name = "jnge", .ops = &jump_ops, },
{ .name = "jnl", .ops = &jump_ops, },
{ .name = "jnle", .ops = &jump_ops, },
{ .name = "jno", .ops = &jump_ops, },
{ .name = "jnp", .ops = &jump_ops, },
{ .name = "jns", .ops = &jump_ops, },
{ .name = "jnz", .ops = &jump_ops, },
{ .name = "jo", .ops = &jump_ops, },
{ .name = "jp", .ops = &jump_ops, },
{ .name = "jpe", .ops = &jump_ops, },
{ .name = "jpo", .ops = &jump_ops, },
{ .name = "jrcxz", .ops = &jump_ops, },
{ .name = "js", .ops = &jump_ops, },
{ .name = "jz", .ops = &jump_ops, },
{ .name = "lea", .ops = &mov_ops, },
{ .name = "lock", .ops = &lock_ops, },
{ .name = "mov", .ops = &mov_ops, },
{ .name = "movapd", .ops = &mov_ops, },
{ .name = "movaps", .ops = &mov_ops, },
{ .name = "movdqa", .ops = &mov_ops, },
{ .name = "movdqu", .ops = &mov_ops, },
{ .name = "movsd", .ops = &mov_ops, },
{ .name = "movss", .ops = &mov_ops, },
{ .name = "movsb", .ops = &mov_ops, },
{ .name = "movsw", .ops = &mov_ops, },
{ .name = "movsl", .ops = &mov_ops, },
{ .name = "movupd", .ops = &mov_ops, },
{ .name = "movups", .ops = &mov_ops, },
{ .name = "movzb", .ops = &mov_ops, },
{ .name = "movzw", .ops = &mov_ops, },
{ .name = "movzl", .ops = &mov_ops, },
{ .name = "mulsd", .ops = &mov_ops, },
{ .name = "mulss", .ops = &mov_ops, },
{ .name = "nop", .ops = &nop_ops, },
{ .name = "or", .ops = &mov_ops, },
{ .name = "orps", .ops = &mov_ops, },
{ .name = "pand", .ops = &mov_ops, },
{ .name = "paddq", .ops = &mov_ops, },
{ .name = "pcmpeqb", .ops = &mov_ops, },
{ .name = "por", .ops = &mov_ops, },
{ .name = "rcl", .ops = &mov_ops, },
{ .name = "ret", .ops = &ret_ops, },
{ .name = "sbb", .ops = &mov_ops, },
{ .name = "sete", .ops = &mov_ops, },
{ .name = "sub", .ops = &mov_ops, },
{ .name = "subsd", .ops = &mov_ops, },
{ .name = "test", .ops = &mov_ops, },
{ .name = "tzcnt", .ops = &mov_ops, },
{ .name = "ucomisd", .ops = &mov_ops, },
{ .name = "ucomiss", .ops = &mov_ops, },
{ .name = "vaddsd", .ops = &mov_ops, },
{ .name = "vandpd", .ops = &mov_ops, },
{ .name = "vmovdqa", .ops = &mov_ops, },
{ .name = "vmovq", .ops = &mov_ops, },
{ .name = "vmovsd", .ops = &mov_ops, },
{ .name = "vmulsd", .ops = &mov_ops, },
{ .name = "vorpd", .ops = &mov_ops, },
{ .name = "vsubsd", .ops = &mov_ops, },
{ .name = "vucomisd", .ops = &mov_ops, },
{ .name = "xadd", .ops = &mov_ops, },
{ .name = "xbegin", .ops = &jump_ops, },
{ .name = "xchg", .ops = &mov_ops, },
{ .name = "xor", .ops = &mov_ops, },
{ .name = "xorpd", .ops = &mov_ops, },
{ .name = "xorps", .ops = &mov_ops, },
};
static bool amd__ins_is_fused(struct arch *arch, const char *ins1,
const char *ins2)
{
if (strstr(ins2, "jmp"))
return false;
/* Family >= 15h supports cmp/test + branch fusion */
if (arch->family >= 0x15 && (strstarts(ins1, "test") ||
(strstarts(ins1, "cmp") && !strstr(ins1, "xchg")))) {
return true;
}
/* Family >= 19h supports some ALU + branch fusion */
if (arch->family >= 0x19 && (strstarts(ins1, "add") ||
strstarts(ins1, "sub") || strstarts(ins1, "and") ||
strstarts(ins1, "inc") || strstarts(ins1, "dec") ||
strstarts(ins1, "or") || strstarts(ins1, "xor"))) {
return true;
}
return false;
}
static bool intel__ins_is_fused(struct arch *arch, const char *ins1,
const char *ins2)
{
if (arch->family != 6 || arch->model < 0x1e || strstr(ins2, "jmp"))
return false;
if (arch->model == 0x1e) {
/* Nehalem */
if ((strstr(ins1, "cmp") && !strstr(ins1, "xchg")) ||
strstr(ins1, "test")) {
return true;
}
} else {
/* Newer platform */
if ((strstr(ins1, "cmp") && !strstr(ins1, "xchg")) ||
strstr(ins1, "test") ||
strstr(ins1, "add") ||
strstr(ins1, "sub") ||
strstr(ins1, "and") ||
strstr(ins1, "inc") ||
strstr(ins1, "dec")) {
return true;
}
}
return false;
}
static int x86__cpuid_parse(struct arch *arch, char *cpuid)
{
unsigned int family, model, stepping;
int ret;
/*
* cpuid = "GenuineIntel,family,model,stepping"
*/
ret = sscanf(cpuid, "%*[^,],%u,%u,%u", &family, &model, &stepping);
if (ret == 3) {
arch->family = family;
arch->model = model;
arch->ins_is_fused = strstarts(cpuid, "AuthenticAMD") ?
amd__ins_is_fused :
intel__ins_is_fused;
return 0;
}
return -1;
}
static int x86__annotate_init(struct arch *arch, char *cpuid)
{
int err = 0;
if (arch->initialized)
return 0;
if (cpuid) {
if (x86__cpuid_parse(arch, cpuid))
err = SYMBOL_ANNOTATE_ERRNO__ARCH_INIT_CPUID_PARSING;
}
arch->e_machine = EM_X86_64;
arch->e_flags = 0;
arch->initialized = true;
return err;
}
#ifdef HAVE_LIBDW_SUPPORT
static void update_insn_state_x86(struct type_state *state,
struct data_loc_info *dloc, Dwarf_Die *cu_die,
struct disasm_line *dl)
{
struct annotated_insn_loc loc;
struct annotated_op_loc *src = &loc.ops[INSN_OP_SOURCE];
struct annotated_op_loc *dst = &loc.ops[INSN_OP_TARGET];
struct type_state_reg *tsr;
Dwarf_Die type_die;
u32 insn_offset = dl->al.offset;
int fbreg = dloc->fbreg;
int fboff = 0;
if (annotate_get_insn_location(dloc->arch, dl, &loc) < 0)
return;
if (ins__is_call(&dl->ins)) {
struct symbol *func = dl->ops.target.sym;
if (func == NULL)
return;
/* __fentry__ will preserve all registers */
if (!strcmp(func->name, "__fentry__"))
return;
pr_debug_dtp("call [%x] %s\n", insn_offset, func->name);
/* Otherwise invalidate caller-saved registers after call */
for (unsigned i = 0; i < ARRAY_SIZE(state->regs); i++) {
if (state->regs[i].caller_saved)
state->regs[i].ok = false;
}
/* Update register with the return type (if any) */
if (die_find_func_rettype(cu_die, func->name, &type_die)) {
tsr = &state->regs[state->ret_reg];
tsr->type = type_die;
tsr->kind = TSR_KIND_TYPE;
tsr->ok = true;
pr_debug_dtp("call [%x] return -> reg%d",
insn_offset, state->ret_reg);
pr_debug_type_name(&type_die, tsr->kind);
}
return;
}
if (!strncmp(dl->ins.name, "add", 3)) {
u64 imm_value = -1ULL;
int offset;
const char *var_name = NULL;
struct map_symbol *ms = dloc->ms;
u64 ip = ms->sym->start + dl->al.offset;
if (!has_reg_type(state, dst->reg1))
return;
tsr = &state->regs[dst->reg1];
tsr->copied_from = -1;
if (src->imm)
imm_value = src->offset;
else if (has_reg_type(state, src->reg1) &&
state->regs[src->reg1].kind == TSR_KIND_CONST)
imm_value = state->regs[src->reg1].imm_value;
else if (src->reg1 == DWARF_REG_PC) {
u64 var_addr = annotate_calc_pcrel(dloc->ms, ip,
src->offset, dl);
if (get_global_var_info(dloc, var_addr,
&var_name, &offset) &&
!strcmp(var_name, "this_cpu_off") &&
tsr->kind == TSR_KIND_CONST) {
tsr->kind = TSR_KIND_PERCPU_BASE;
tsr->ok = true;
imm_value = tsr->imm_value;
}
}
else
return;
if (tsr->kind != TSR_KIND_PERCPU_BASE)
return;
if (get_global_var_type(cu_die, dloc, ip, imm_value, &offset,
&type_die) && offset == 0) {
/*
* This is not a pointer type, but it should be treated
* as a pointer.
*/
tsr->type = type_die;
tsr->kind = TSR_KIND_POINTER;
tsr->ok = true;
pr_debug_dtp("add [%x] percpu %#"PRIx64" -> reg%d",
insn_offset, imm_value, dst->reg1);
pr_debug_type_name(&tsr->type, tsr->kind);
}
return;
}
if (strncmp(dl->ins.name, "mov", 3))
return;
if (dloc->fb_cfa) {
u64 ip = dloc->ms->sym->start + dl->al.offset;
u64 pc = map__rip_2objdump(dloc->ms->map, ip);
if (die_get_cfa(dloc->di->dbg, pc, &fbreg, &fboff) < 0)
fbreg = -1;
}
/* Case 1. register to register or segment:offset to register transfers */
if (!src->mem_ref && !dst->mem_ref) {
if (!has_reg_type(state, dst->reg1))
return;
tsr = &state->regs[dst->reg1];
tsr->copied_from = -1;
if (dso__kernel(map__dso(dloc->ms->map)) &&
src->segment == INSN_SEG_X86_GS && src->imm) {
u64 ip = dloc->ms->sym->start + dl->al.offset;
u64 var_addr;
int offset;
/*
* In kernel, %gs points to a per-cpu region for the
* current CPU. Access with a constant offset should
* be treated as a global variable access.
*/
var_addr = src->offset;
if (var_addr == 40) {
tsr->kind = TSR_KIND_CANARY;
tsr->ok = true;
pr_debug_dtp("mov [%x] stack canary -> reg%d\n",
insn_offset, dst->reg1);
return;
}
if (!get_global_var_type(cu_die, dloc, ip, var_addr,
&offset, &type_die) ||
!die_get_member_type(&type_die, offset, &type_die)) {
tsr->ok = false;
return;
}
tsr->type = type_die;
tsr->kind = TSR_KIND_TYPE;
tsr->ok = true;
pr_debug_dtp("mov [%x] this-cpu addr=%#"PRIx64" -> reg%d",
insn_offset, var_addr, dst->reg1);
pr_debug_type_name(&tsr->type, tsr->kind);
return;
}
if (src->imm) {
tsr->kind = TSR_KIND_CONST;
tsr->imm_value = src->offset;
tsr->ok = true;
pr_debug_dtp("mov [%x] imm=%#x -> reg%d\n",
insn_offset, tsr->imm_value, dst->reg1);
return;
}
if (!has_reg_type(state, src->reg1) ||
!state->regs[src->reg1].ok) {
tsr->ok = false;
return;
}
tsr->type = state->regs[src->reg1].type;
tsr->kind = state->regs[src->reg1].kind;
tsr->imm_value = state->regs[src->reg1].imm_value;
tsr->ok = true;
/* To copy back the variable type later (hopefully) */
if (tsr->kind == TSR_KIND_TYPE)
tsr->copied_from = src->reg1;
pr_debug_dtp("mov [%x] reg%d -> reg%d",
insn_offset, src->reg1, dst->reg1);
pr_debug_type_name(&tsr->type, tsr->kind);
}
/* Case 2. memory to register transers */
if (src->mem_ref && !dst->mem_ref) {
int sreg = src->reg1;
if (!has_reg_type(state, dst->reg1))
return;
tsr = &state->regs[dst->reg1];
tsr->copied_from = -1;
retry:
/* Check stack variables with offset */
if (sreg == fbreg || sreg == state->stack_reg) {
struct type_state_stack *stack;
int offset = src->offset - fboff;
stack = find_stack_state(state, offset);
if (stack == NULL) {
tsr->ok = false;
return;
} else if (!stack->compound) {
tsr->type = stack->type;
tsr->kind = stack->kind;
tsr->ok = true;
} else if (die_get_member_type(&stack->type,
offset - stack->offset,
&type_die)) {
tsr->type = type_die;
tsr->kind = TSR_KIND_TYPE;
tsr->ok = true;
} else {
tsr->ok = false;
return;
}
if (sreg == fbreg) {
pr_debug_dtp("mov [%x] -%#x(stack) -> reg%d",
insn_offset, -offset, dst->reg1);
} else {
pr_debug_dtp("mov [%x] %#x(reg%d) -> reg%d",
insn_offset, offset, sreg, dst->reg1);
}
pr_debug_type_name(&tsr->type, tsr->kind);
}
/* And then dereference the pointer if it has one */
else if (has_reg_type(state, sreg) && state->regs[sreg].ok &&
state->regs[sreg].kind == TSR_KIND_TYPE &&
die_deref_ptr_type(&state->regs[sreg].type,
src->offset, &type_die)) {
tsr->type = type_die;
tsr->kind = TSR_KIND_TYPE;
tsr->ok = true;
pr_debug_dtp("mov [%x] %#x(reg%d) -> reg%d",
insn_offset, src->offset, sreg, dst->reg1);
pr_debug_type_name(&tsr->type, tsr->kind);
}
/* Or check if it's a global variable */
else if (sreg == DWARF_REG_PC) {
struct map_symbol *ms = dloc->ms;
u64 ip = ms->sym->start + dl->al.offset;
u64 addr;
int offset;
addr = annotate_calc_pcrel(ms, ip, src->offset, dl);
if (!get_global_var_type(cu_die, dloc, ip, addr, &offset,
&type_die) ||
!die_get_member_type(&type_die, offset, &type_die)) {
tsr->ok = false;
return;
}
tsr->type = type_die;
tsr->kind = TSR_KIND_TYPE;
tsr->ok = true;
pr_debug_dtp("mov [%x] global addr=%"PRIx64" -> reg%d",
insn_offset, addr, dst->reg1);
pr_debug_type_name(&type_die, tsr->kind);
}
/* And check percpu access with base register */
else if (has_reg_type(state, sreg) &&
state->regs[sreg].kind == TSR_KIND_PERCPU_BASE) {
u64 ip = dloc->ms->sym->start + dl->al.offset;
u64 var_addr = src->offset;
int offset;
if (src->multi_regs) {
int reg2 = (sreg == src->reg1) ? src->reg2 : src->reg1;
if (has_reg_type(state, reg2) && state->regs[reg2].ok &&
state->regs[reg2].kind == TSR_KIND_CONST)
var_addr += state->regs[reg2].imm_value;
}
/*
* In kernel, %gs points to a per-cpu region for the
* current CPU. Access with a constant offset should
* be treated as a global variable access.
*/
if (get_global_var_type(cu_die, dloc, ip, var_addr,
&offset, &type_die) &&
die_get_member_type(&type_die, offset, &type_die)) {
tsr->type = type_die;
tsr->kind = TSR_KIND_TYPE;
tsr->ok = true;
if (src->multi_regs) {
pr_debug_dtp("mov [%x] percpu %#x(reg%d,reg%d) -> reg%d",
insn_offset, src->offset, src->reg1,
src->reg2, dst->reg1);
} else {
pr_debug_dtp("mov [%x] percpu %#x(reg%d) -> reg%d",
insn_offset, src->offset, sreg, dst->reg1);
}
pr_debug_type_name(&tsr->type, tsr->kind);
} else {
tsr->ok = false;
}
}
/* And then dereference the calculated pointer if it has one */
else if (has_reg_type(state, sreg) && state->regs[sreg].ok &&
state->regs[sreg].kind == TSR_KIND_POINTER &&
die_get_member_type(&state->regs[sreg].type,
src->offset, &type_die)) {
tsr->type = type_die;
tsr->kind = TSR_KIND_TYPE;
tsr->ok = true;
pr_debug_dtp("mov [%x] pointer %#x(reg%d) -> reg%d",
insn_offset, src->offset, sreg, dst->reg1);
pr_debug_type_name(&tsr->type, tsr->kind);
}
/* Or try another register if any */
else if (src->multi_regs && sreg == src->reg1 &&
src->reg1 != src->reg2) {
sreg = src->reg2;
goto retry;
}
else {
int offset;
const char *var_name = NULL;
/* it might be per-cpu variable (in kernel) access */
if (src->offset < 0) {
if (get_global_var_info(dloc, (s64)src->offset,
&var_name, &offset) &&
!strcmp(var_name, "__per_cpu_offset")) {
tsr->kind = TSR_KIND_PERCPU_BASE;
tsr->ok = true;
pr_debug_dtp("mov [%x] percpu base reg%d\n",
insn_offset, dst->reg1);
return;
}
}
tsr->ok = false;
}
}
/* Case 3. register to memory transfers */
if (!src->mem_ref && dst->mem_ref) {
if (!has_reg_type(state, src->reg1) ||
!state->regs[src->reg1].ok)
return;
/* Check stack variables with offset */
if (dst->reg1 == fbreg || dst->reg1 == state->stack_reg) {
struct type_state_stack *stack;
int offset = dst->offset - fboff;
tsr = &state->regs[src->reg1];
stack = find_stack_state(state, offset);
if (stack) {
/*
* The source register is likely to hold a type
* of member if it's a compound type. Do not
* update the stack variable type since we can
* get the member type later by using the
* die_get_member_type().
*/
if (!stack->compound)
set_stack_state(stack, offset, tsr->kind,
&tsr->type);
} else {
findnew_stack_state(state, offset, tsr->kind,
&tsr->type);
}
if (dst->reg1 == fbreg) {
pr_debug_dtp("mov [%x] reg%d -> -%#x(stack)",
insn_offset, src->reg1, -offset);
} else {
pr_debug_dtp("mov [%x] reg%d -> %#x(reg%d)",
insn_offset, src->reg1, offset, dst->reg1);
}
pr_debug_type_name(&tsr->type, tsr->kind);
}
/*
* Ignore other transfers since it'd set a value in a struct
* and won't change the type.
*/
}
/* Case 4. memory to memory transfers (not handled for now) */
}
#endif