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>

diff --git a/tools/perf/arch/x86/annotate/instructions.c b/tools/perf/arch/x86/annotate/instructions.c
index ae94b1f..c6d403e 100644 (file)
--- 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 976abed..eaf96fa 100644 (file)
--- 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) {