Like global variables, this per-cpu variables should be tracked
correctly. Factor our get_global_var_type() to handle both global
and per-cpu (for this cpu) variables in the same manner.
Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
tools/perf/util/annotate-data.c | 84 +++++++++++++++++++++++----------
1 file changed, 60 insertions(+), 24 deletions(-)
diff --git a/tools/perf/util/annotate-data.c b/tools/perf/util/annotate-data.c
index cebbe17de64a..9d6cc6ac431c 100644
--- a/tools/perf/util/annotate-data.c
+++ b/tools/perf/util/annotate-data.c
@@ -410,6 +410,37 @@ void update_var_state(struct type_state *state, struct data_loc_info *dloc,
}
}
+static bool get_global_var_type(Dwarf_Die *cu_die, struct map_symbol *ms, u64 ip,
+ u64 var_addr, const char *var_name, int var_offset,
+ Dwarf_Die *type_die)
+{
+ u64 pc;
+ int offset = var_offset;
+ bool is_pointer = false;
+ Dwarf_Die var_die;
+
+ pc = map__rip_2objdump(ms->map, ip);
+
+ /* Try to get the variable by address first */
+ if (die_find_variable_by_addr(cu_die, pc, var_addr, &var_die, &offset) &&
+ check_variable(&var_die, type_die, offset, is_pointer) == 0 &&
+ die_get_member_type(type_die, offset, type_die))
+ return true;
+
+ if (var_name == NULL)
+ return false;
+
+ offset = var_offset;
+
+ /* Try to get the name of global variable */
+ if (die_find_variable_at(cu_die, var_name, pc, &var_die) &&
+ check_variable(&var_die, type_die, offset, is_pointer) == 0 &&
+ die_get_member_type(type_die, offset, type_die))
+ return true;
+
+ return false;
+}
+
/**
* update_insn_state - Update type state for an instruction
* @state: type state table
@@ -473,14 +504,36 @@ void update_insn_state(struct type_state *state, struct data_loc_info *dloc,
fbreg = -1;
}
- /* Case 1. register to register transfers */
+ /* 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;
if (has_reg_type(state, src->reg1))
state->regs[dst->reg1] = state->regs[src->reg1];
- else
+ else if (map__dso(dloc->ms->map)->kernel &&
+ src->segment == INSN_SEG_X86_GS) {
+ struct map_symbol *ms = dloc->ms;
+ int offset = src->offset;
+ u64 ip = ms->sym->start + dl->al.offset;
+ const char *var_name = NULL;
+ u64 var_addr;
+
+ /*
+ * 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;
+ get_percpu_var_info(dloc->thread, ms, dloc->cpumode,
+ var_addr, &var_name, &offset);
+
+ if (get_global_var_type(cu_die, ms, ip, var_addr,
+ var_name, offset, &type_die)) {
+ state->regs[dst->reg1].type = type_die;
+ state->regs[dst->reg1].ok = true;
+ }
+ } else
state->regs[dst->reg1].ok = false;
}
/* Case 2. memory to register transers */
@@ -493,37 +546,20 @@ void update_insn_state(struct type_state *state, struct data_loc_info *dloc,
retry:
/* Check if it's a global variable */
if (sreg == DWARF_REG_PC) {
- Dwarf_Die var_die;
struct map_symbol *ms = dloc->ms;
int offset = src->offset;
u64 ip = ms->sym->start + dl->al.offset;
- u64 pc, addr;
const char *var_name = NULL;
+ u64 var_addr;
- addr = annotate_calc_pcrel(ms, ip, offset, dl);
- pc = map__rip_2objdump(ms->map, ip);
-
- if (die_find_variable_by_addr(cu_die, pc, addr,
- &var_die, &offset) &&
- check_variable(&var_die, &type_die, offset,
- /*is_pointer=*/false) == 0 &&
- die_get_member_type(&type_die, offset, &type_die)) {
- state->regs[dst->reg1].type = type_die;
- state->regs[dst->reg1].ok = true;
- return;
- }
+ var_addr = annotate_calc_pcrel(ms, ip, offset, dl);
- /* Try to get the name of global variable */
- offset = src->offset;
get_global_var_info(dloc->thread, ms, ip, dl,
- dloc->cpumode, &addr,
+ dloc->cpumode, &var_addr,
&var_name, &offset);
- if (var_name && die_find_variable_at(cu_die, var_name,
- pc, &var_die) &&
- check_variable(&var_die, &type_die, offset,
- /*is_pointer=*/false) == 0 &&
- die_get_member_type(&type_die, offset, &type_die)) {
+ if (get_global_var_type(cu_die, ms, ip, var_addr,
+ var_name, offset, &type_die)) {
state->regs[dst->reg1].type = type_die;
state->regs[dst->reg1].ok = true;
} else
--
2.43.0.594.gd9cf4e227d-goog
|