[PATCH 36/48] perf annotate-data: Introduce struct data_loc_info

From: Namhyung Kim
Date: Thu Oct 12 2023 - 00:02:07 EST


The find_data_type() needs many information to describe the location of
the data. Add the new struct data_loc_info to pass those information at
once.

No functional changes intended.

Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
tools/perf/util/annotate-data.c | 83 +++++++++++++++++----------------
tools/perf/util/annotate-data.h | 38 ++++++++++++---
tools/perf/util/annotate.c | 30 ++++++------
3 files changed, 91 insertions(+), 60 deletions(-)

diff --git a/tools/perf/util/annotate-data.c b/tools/perf/util/annotate-data.c
index 39bbd56b2160..90793cbb6aa0 100644
--- a/tools/perf/util/annotate-data.c
+++ b/tools/perf/util/annotate-data.c
@@ -256,21 +256,28 @@ static int check_variable(Dwarf_Die *var_die, Dwarf_Die *type_die, int offset,
}

/* The result will be saved in @type_die */
-static int find_data_type_die(struct debuginfo *di, u64 pc, u64 addr,
- const char *var_name, struct annotated_op_loc *loc,
- Dwarf_Die *type_die)
+static int find_data_type_die(struct data_loc_info *dloc, Dwarf_Die *type_die)
{
+ struct annotated_op_loc *loc = dloc->op;
Dwarf_Die cu_die, var_die;
Dwarf_Die *scopes = NULL;
int reg, offset;
int ret = -1;
int i, nr_scopes;
int fbreg = -1;
- bool is_fbreg = false;
int fb_offset = 0;
+ bool is_fbreg = false;
+ u64 pc;
+
+ /*
+ * IP is a relative instruction address from the start of the map, as
+ * it can be randomized/relocated, it needs to translate to PC which is
+ * a file address for DWARF processing.
+ */
+ pc = map__rip_2objdump(dloc->ms->map, dloc->ip);

/* Get a compile_unit for this address */
- if (!find_cu_die(di, pc, &cu_die)) {
+ if (!find_cu_die(dloc->di, pc, &cu_die)) {
pr_debug("cannot find CU for address %lx\n", pc);
ann_data_stat.no_cuinfo++;
return -1;
@@ -280,18 +287,19 @@ static int find_data_type_die(struct debuginfo *di, u64 pc, u64 addr,
offset = loc->offset;

if (reg == DWARF_REG_PC) {
- if (die_find_variable_by_addr(&cu_die, pc, addr, &var_die, &offset)) {
+ if (die_find_variable_by_addr(&cu_die, pc, dloc->var_addr,
+ &var_die, &offset)) {
ret = check_variable(&var_die, type_die, offset,
/*is_pointer=*/false);
- loc->offset = offset;
+ dloc->type_offset = offset;
goto out;
}

- if (var_name && die_find_variable_at(&cu_die, var_name, pc,
- &var_die)) {
- ret = check_variable(&var_die, type_die, 0,
+ if (dloc->var_name &&
+ die_find_variable_at(&cu_die, dloc->var_name, pc, &var_die)) {
+ ret = check_variable(&var_die, type_die, dloc->type_offset,
/*is_pointer=*/false);
- /* loc->offset will be updated by the caller */
+ /* dloc->type_offset was updated by the caller */
goto out;
}
}
@@ -308,10 +316,11 @@ static int find_data_type_die(struct debuginfo *di, u64 pc, u64 addr,
dwarf_formblock(&attr, &block) == 0 && block.length == 1) {
switch (*block.data) {
case DW_OP_reg0 ... DW_OP_reg31:
- fbreg = *block.data - DW_OP_reg0;
+ fbreg = dloc->fbreg = *block.data - DW_OP_reg0;
break;
case DW_OP_call_frame_cfa:
- if (die_get_cfa(di->dbg, pc, &fbreg,
+ dloc->fb_cfa = true;
+ if (die_get_cfa(dloc->di->dbg, pc, &fbreg,
&fb_offset) < 0)
fbreg = -1;
break;
@@ -329,7 +338,7 @@ static int find_data_type_die(struct debuginfo *di, u64 pc, u64 addr,
/* Search from the inner-most scope to the outer */
for (i = nr_scopes - 1; i >= 0; i--) {
if (reg == DWARF_REG_PC) {
- if (!die_find_variable_by_addr(&scopes[i], pc, addr,
+ if (!die_find_variable_by_addr(&scopes[i], pc, dloc->var_addr,
&var_die, &offset))
continue;
} else {
@@ -342,7 +351,7 @@ static int find_data_type_die(struct debuginfo *di, u64 pc, u64 addr,
/* Found a variable, see if it's correct */
ret = check_variable(&var_die, type_die, offset,
reg != DWARF_REG_PC && !is_fbreg);
- loc->offset = offset;
+ dloc->type_offset = offset;
goto out;
}

@@ -361,50 +370,46 @@ static int find_data_type_die(struct debuginfo *di, u64 pc, u64 addr,

/**
* find_data_type - Return a data type at the location
- * @ms: map and symbol at the location
- * @ip: instruction address of the memory access
- * @loc: instruction operand location
- * @addr: data address of the memory access
- * @var_name: global variable name
+ * @dloc: data location
*
* This functions searches the debug information of the binary to get the data
- * type it accesses. The exact location is expressed by (@ip, reg, offset)
- * for pointer variables or (@ip, @addr) for global variables. Note that global
- * variables might update the @loc->offset after finding the start of the variable.
- * If it cannot find a global variable by address, it tried to fine a declaration
- * of the variable using @var_name. In that case, @loc->offset won't be updated.
+ * type it accesses. The exact location is expressed by (ip, reg, offset)
+ * for pointer variables or (ip, addr) for global variables. Note that global
+ * variables might update the @dloc->type_offset after finding the start of the
+ * variable. If it cannot find a global variable by address, it tried to find
+ * a declaration of the variable using var_name. In that case, @dloc->offset
+ * won't be updated.
*
* It return %NULL if not found.
*/
-struct annotated_data_type *find_data_type(struct map_symbol *ms, u64 ip,
- struct annotated_op_loc *loc, u64 addr,
- const char *var_name)
+struct annotated_data_type *find_data_type(struct data_loc_info *dloc)
{
struct annotated_data_type *result = NULL;
- struct dso *dso = ms->map->dso;
- struct debuginfo *di;
+ struct dso *dso = dloc->ms->map->dso;
Dwarf_Die type_die;
- u64 pc;

- di = debuginfo__new(dso->long_name);
- if (di == NULL) {
+ dloc->di = debuginfo__new(dso->long_name);
+ if (dloc->di == NULL) {
pr_debug("cannot get the debug info\n");
return NULL;
}

/*
- * IP is a relative instruction address from the start of the map, as
- * it can be randomized/relocated, it needs to translate to PC which is
- * a file address for DWARF processing.
+ * The type offset is the same as instruction offset by default.
+ * But when finding a global variable, the offset won't be valid.
*/
- pc = map__rip_2objdump(ms->map, ip);
- if (find_data_type_die(di, pc, addr, var_name, loc, &type_die) < 0)
+ if (dloc->var_name == NULL)
+ dloc->type_offset = dloc->op->offset;
+
+ dloc->fbreg = -1;
+
+ if (find_data_type_die(dloc, &type_die) < 0)
goto out;

result = dso__findnew_data_type(dso, &type_die);

out:
- debuginfo__delete(di);
+ debuginfo__delete(dloc->di);
return result;
}

diff --git a/tools/perf/util/annotate-data.h b/tools/perf/util/annotate-data.h
index 1b0db8e8c40e..ad6493ea2c8e 100644
--- a/tools/perf/util/annotate-data.h
+++ b/tools/perf/util/annotate-data.h
@@ -8,6 +8,7 @@
#include <linux/types.h>

struct annotated_op_loc;
+struct debuginfo;
struct evsel;
struct map_symbol;

@@ -72,6 +73,35 @@ struct annotated_data_type {
extern struct annotated_data_type unknown_type;
extern struct annotated_data_type stackop_type;

+/**
+ * struct data_loc_info - Data location information
+ * @ms: Map and Symbol info
+ * @ip: Instruction address
+ * @var_addr: Data address (for global variables)
+ * @var_name: Variable name (for global variables)
+ * @op: Instruction operand location (regs and offset)
+ * @di: Debug info
+ * @fbreg: Frame base register
+ * @fb_cfa: Whether the frame needs to check CFA
+ * @type_offset: Final offset in the type
+ */
+struct data_loc_info {
+ /* These are input field, should be filled by caller */
+ struct map_symbol *ms;
+ u64 ip;
+ u64 var_addr;
+ const char *var_name;
+ struct annotated_op_loc *op;
+
+ /* These are used internally */
+ struct debuginfo *di;
+ int fbreg;
+ bool fb_cfa;
+
+ /* This is for the result */
+ int type_offset;
+};
+
/**
* struct annotated_data_stat - Debug statistics
* @total: Total number of entry
@@ -106,9 +136,7 @@ extern struct annotated_data_stat ann_data_stat;
#ifdef HAVE_DWARF_SUPPORT

/* Returns data type at the location (ip, reg, offset) */
-struct annotated_data_type *find_data_type(struct map_symbol *ms, u64 ip,
- struct annotated_op_loc *loc, u64 addr,
- const char *var_name);
+struct annotated_data_type *find_data_type(struct data_loc_info *dloc);

/* Update type access histogram at the given offset */
int annotated_data_type__update_samples(struct annotated_data_type *adt,
@@ -121,9 +149,7 @@ void annotated_data_type__tree_delete(struct rb_root *root);
#else /* HAVE_DWARF_SUPPORT */

static inline struct annotated_data_type *
-find_data_type(struct map_symbol *ms __maybe_unused, u64 ip __maybe_unused,
- struct annotated_op_loc *loc __maybe_unused,
- u64 addr __maybe_unused, const char *var_name __maybe_unused)
+find_data_type(struct data_loc_info *dloc __maybe_unused)
{
return NULL;
}
diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index fe0074bb98f0..1cf55f903ee4 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -3744,9 +3744,7 @@ struct annotated_data_type *hist_entry__get_data_type(struct hist_entry *he)
struct annotated_op_loc *op_loc;
struct annotated_data_type *mem_type;
struct annotated_item_stat *istat;
- u64 ip = he->ip, addr = 0;
- const char *var_name = NULL;
- int var_offset;
+ u64 ip = he->ip;
int i;

ann_data_stat.total++;
@@ -3794,51 +3792,53 @@ struct annotated_data_type *hist_entry__get_data_type(struct hist_entry *he)
}

for_each_insn_op_loc(&loc, i, op_loc) {
+ struct data_loc_info dloc = {
+ .ms = ms,
+ /* Recalculate IP for LOCK prefix or insn fusion */
+ .ip = ms->sym->start + dl->al.offset,
+ .op = op_loc,
+ };
+
if (!op_loc->mem_ref)
continue;

/* Recalculate IP because of LOCK prefix or insn fusion */
ip = ms->sym->start + dl->al.offset;

- var_offset = op_loc->offset;
-
/* PC-relative addressing */
if (op_loc->reg1 == DWARF_REG_PC) {
struct addr_location al;
struct symbol *var;
u64 map_addr;

- addr = annotate_calc_pcrel(ms, ip, op_loc->offset, dl);
+ dloc.var_addr = annotate_calc_pcrel(ms, ip, op_loc->offset, dl);
/* Kernel symbols might be relocated */
- map_addr = addr + map__reloc(ms->map);
+ map_addr = dloc.var_addr + map__reloc(ms->map);

addr_location__init(&al);
var = thread__find_symbol_fb(he->thread, he->cpumode,
map_addr, &al);
if (var) {
- var_name = var->name;
+ dloc.var_name = var->name;
/* Calculate type offset from the start of variable */
- var_offset = map_addr - map__unmap_ip(al.map, var->start);
+ dloc.type_offset = map_addr - map__unmap_ip(al.map, var->start);
}
addr_location__exit(&al);
}

- mem_type = find_data_type(ms, ip, op_loc, addr, var_name);
+ mem_type = find_data_type(&dloc);
if (mem_type)
istat->good++;
else
istat->bad++;

- if (mem_type && var_name)
- op_loc->offset = var_offset;
-
if (symbol_conf.annotate_data_sample) {
annotated_data_type__update_samples(mem_type, evsel,
- op_loc->offset,
+ dloc.type_offset,
he->stat.nr_events,
he->stat.period);
}
- he->mem_type_off = op_loc->offset;
+ he->mem_type_off = dloc.type_offset;
return mem_type;
}

--
2.42.0.655.g421f12c284-goog