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>

2 files changed, 26 insertions, 11 deletions

diff --git a/tools/perf/arch/x86/annotate/instructions.c b/tools/perf/arch/x86/annotate/instructions.c
index ae94b1f0b9cc..c6d403eae744 100644
--- a/tools/perf/arch/x86/annotate/instructions.c
+++ b/tools/perf/arch/x86/annotate/instructions.c
@@ -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 @@ retry:
 				return;
 			}
 
-			pr_debug_dtp("mov [%x] -%#x(stack) -> reg%d",
-				     insn_offset, -offset, dst->reg1);
+			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 @@ retry:
 			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 @@ retry:
 						    &tsr->type);
 			}
 
-			pr_debug_dtp("mov [%x] reg%d -> -%#x(stack)",
-				     insn_offset, src->reg1, -offset);
+			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);
 		}
 		/*
diff --git a/tools/perf/util/annotate-data.c b/tools/perf/util/annotate-data.c
index 976abedca09e..eaf96fa80c83 100644
--- a/tools/perf/util/annotate-data.c
+++ b/tools/perf/util/annotate-data.c
@@ -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);
 
-			pr_debug_dtp("var [%"PRIx64"] -%#x(stack)",
-				     insn_offset, -offset);
+			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 @@ again:
 	}
 
 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) {