perf dwarf-aux: Better variable collection for insn tracking

Utilizes the previous is_breg_access_indirect function to determine if
the register + offset stores the variable itself or the struct it points
to, save the information in die_var_type.is_reg_var_addr.

Since we are storing the real types in the stack state, we need to do a
type dereference when is_reg_var_addr is set to false for stack/frame
registers.

For other gp registers, skip the variable when the register is a pointer
to the type. If we want to accept these variables, we might also utilize
is_reg_var_addr in a different way, we need to mark that register as a
pointer to the type.

Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Zecheng Li <zecheng@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Xu Liu <xliuprof@google.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/tools/perf/util/annotate-data.c b/tools/perf/util/annotate-data.c
index 1ef2edbc71d9..258157cc43c2 100644
--- a/tools/perf/util/annotate-data.c
+++ b/tools/perf/util/annotate-data.c
@@ -868,6 +868,11 @@ static void update_var_state(struct type_state *state, struct data_loc_info *dlo
 			int offset = var->offset;
 			struct type_state_stack *stack;
 
+			/* If the reg location holds the pointer value, dereference the type */
+			if (!var->is_reg_var_addr && is_pointer_type(&mem_die) &&
+				__die_get_real_type(&mem_die, &mem_die) == NULL)
+				continue;
+
 			if (var->reg != DWARF_REG_FB)
 				offset -= fb_offset;
 
@@ -893,6 +898,10 @@ static void update_var_state(struct type_state *state, struct data_loc_info *dlo
 
 			reg = &state->regs[var->reg];
 
+			/* For gp registers, skip the address registers for now */
+			if (var->is_reg_var_addr)
+				continue;
+
 			if (reg->ok && reg->kind == TSR_KIND_TYPE &&
 			    !is_better_type(&reg->type, &mem_die))
 				continue;