Commit f4dc5a33 authored by Namhyung Kim's avatar Namhyung Kim
Browse files

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: default avatarBlake Jones <blakejones@google.com>
Link: https://lore.kernel.org/r/20250126210242.1181225-1-namhyung@kernel.org


Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
parent c40aa8d9

tools/perf/arch/x86/annotate/instructions.c

+16 −6
Original line number Diff line number Diff line
@@ -410,7 +410,7 @@ static void update_insn_state_x86(struct type_state *state, 


retry:

		/* Check stack variables with offset */

		if (sreg == fbreg) {

		if (sreg == fbreg || sreg == state->stack_reg) {

			struct type_state_stack *stack;

			int offset = src->offset - fboff;
@@ -433,8 +433,13 @@ static void update_insn_state_x86(struct type_state *state, 
				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 */
@@ -561,7 +566,7 @@ static void update_insn_state_x86(struct type_state *state, 
			return;



		/* Check stack variables with offset */

		if (dst->reg1 == fbreg) {

		if (dst->reg1 == fbreg || dst->reg1 == state->stack_reg) {

			struct type_state_stack *stack;

			int offset = dst->offset - fboff;
@@ -584,8 +589,13 @@ static void update_insn_state_x86(struct type_state *state, 
						    &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);

		}

		/*

tools/perf/util/annotate-data.c

+10 −5
Original line number Diff line number Diff line
@@ -830,7 +830,7 @@ static void update_var_state(struct type_state *state, struct data_loc_info *dlo 
		if (!dwarf_offdie(dloc->di->dbg, var->die_off, &mem_die))

			continue;



		if (var->reg == DWARF_REG_FB || var->reg == fbreg) {

		if (var->reg == DWARF_REG_FB || var->reg == fbreg || var->reg == state->stack_reg) {

			int offset = var->offset;

			struct type_state_stack *stack;
@@ -845,8 +845,13 @@ static void update_var_state(struct type_state *state, struct data_loc_info *dlo 
			findnew_stack_state(state, offset, TSR_KIND_TYPE,

					    &mem_die);



			if (var->reg == state->stack_reg) {

				pr_debug_dtp("var [%"PRIx64"] %#x(reg%d)",

					     insn_offset, offset, state->stack_reg);

			} else {

				pr_debug_dtp("var [%"PRIx64"] -%#x(stack)",

					     insn_offset, -offset);

			}

			pr_debug_type_name(&mem_die, TSR_KIND_TYPE);

		} else if (has_reg_type(state, var->reg) && var->offset == 0) {

			struct type_state_reg *reg;
@@ -1127,10 +1132,10 @@ static enum type_match_result check_matching_type(struct type_state *state, 
	}



check_non_register:

	if (reg == dloc->fbreg) {

	if (reg == dloc->fbreg || reg == state->stack_reg) {

		struct type_state_stack *stack;



		pr_debug_dtp("fbreg");

		pr_debug_dtp("%s", reg == dloc->fbreg ? "fbreg" : "stack");



		stack = find_stack_state(state, dloc->type_offset);

		if (stack == NULL) {