[06/14] perf annotate-data: Maintain variable type info
Commit Message
As it collected basic block and variable information in each scope, it
now can build a state table to find matching variable at the location.
The struct type_state is to keep the type info saved in each register
and stack slot. The update_var_state() updates the table when it finds
variables in the current address. It expects die_collect_vars() filled
a list of variables with type info and starting address.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
tools/perf/util/annotate-data.c | 155 ++++++++++++++++++++++++++++++++
tools/perf/util/annotate-data.h | 29 ++++++
tools/perf/util/dwarf-aux.c | 4 +
3 files changed, 188 insertions(+)
Comments
On Fri, Feb 2, 2024 at 2:05 PM Namhyung Kim <namhyung@kernel.org> wrote:
>
> As it collected basic block and variable information in each scope, it
> now can build a state table to find matching variable at the location.
>
> The struct type_state is to keep the type info saved in each register
> and stack slot. The update_var_state() updates the table when it finds
> variables in the current address. It expects die_collect_vars() filled
> a list of variables with type info and starting address.
>
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> ---
> tools/perf/util/annotate-data.c | 155 ++++++++++++++++++++++++++++++++
> tools/perf/util/annotate-data.h | 29 ++++++
> tools/perf/util/dwarf-aux.c | 4 +
> 3 files changed, 188 insertions(+)
>
> diff --git a/tools/perf/util/annotate-data.c b/tools/perf/util/annotate-data.c
> index b8e60c42af8c..f8768c224bcc 100644
> --- a/tools/perf/util/annotate-data.c
> +++ b/tools/perf/util/annotate-data.c
> @@ -23,6 +23,57 @@
> #include "symbol.h"
> #include "symbol_conf.h"
>
> +/* Type information in a register, valid when ok is true */
> +struct type_state_reg {
> + Dwarf_Die type;
> + bool ok;
> + bool scratch;
> +};
> +
> +/* Type information in a stack location, dynamically allocated */
> +struct type_state_stack {
> + struct list_head list;
> + Dwarf_Die type;
> + int offset;
> + int size;
> + bool compound;
> +};
> +
> +/* FIXME: This should be arch-dependent */
> +#define TYPE_STATE_MAX_REGS 16
Perhaps 32, presumably 16 won't work on Arm64.
Thanks,
Ian
> +
> +/*
> + * State table to maintain type info in each register and stack location.
> + * It'll be updated when new variable is allocated or type info is moved
> + * to a new location (register or stack). As it'd be used with the
> + * shortest path of basic blocks, it only maintains a single table.
> + */
> +struct type_state {
> + struct type_state_reg regs[TYPE_STATE_MAX_REGS];
> + struct list_head stack_vars;
> +};
> +
> +static bool has_reg_type(struct type_state *state, int reg)
> +{
> + return (unsigned)reg < ARRAY_SIZE(state->regs);
> +}
> +
> +void init_type_state(struct type_state *state, struct arch *arch __maybe_unused)
> +{
> + memset(state, 0, sizeof(*state));
> + INIT_LIST_HEAD(&state->stack_vars);
> +}
> +
> +void exit_type_state(struct type_state *state)
> +{
> + struct type_state_stack *stack, *tmp;
> +
> + list_for_each_entry_safe(stack, tmp, &state->stack_vars, list) {
> + list_del(&stack->list);
> + free(stack);
> + }
> +}
> +
> /*
> * Compare type name and size to maintain them in a tree.
> * I'm not sure if DWARF would have information of a single type in many
> @@ -238,6 +289,110 @@ static int check_variable(Dwarf_Die *var_die, Dwarf_Die *type_die, int offset,
> return 0;
> }
>
> +static struct type_state_stack *find_stack_state(struct type_state *state,
> + int offset)
> +{
> + struct type_state_stack *stack;
> +
> + list_for_each_entry(stack, &state->stack_vars, list) {
> + if (offset == stack->offset)
> + return stack;
> +
> + if (stack->compound && stack->offset < offset &&
> + offset < stack->offset + stack->size)
> + return stack;
> + }
> + return NULL;
> +}
> +
> +static void set_stack_state(struct type_state_stack *stack, int offset,
> + Dwarf_Die *type_die)
> +{
> + int tag;
> + Dwarf_Word size;
> +
> + if (dwarf_aggregate_size(type_die, &size) < 0)
> + size = 0;
> +
> + tag = dwarf_tag(type_die);
> +
> + stack->type = *type_die;
> + stack->size = size;
> + stack->offset = offset;
> +
> + switch (tag) {
> + case DW_TAG_structure_type:
> + case DW_TAG_union_type:
> + stack->compound = true;
> + break;
> + default:
> + stack->compound = false;
> + break;
> + }
> +}
> +
> +static struct type_state_stack *findnew_stack_state(struct type_state *state,
> + int offset, Dwarf_Die *type_die)
> +{
> + struct type_state_stack *stack = find_stack_state(state, offset);
> +
> + if (stack) {
> + set_stack_state(stack, offset, type_die);
> + return stack;
> + }
> +
> + stack = malloc(sizeof(*stack));
> + if (stack) {
> + set_stack_state(stack, offset, type_die);
> + list_add(&stack->list, &state->stack_vars);
> + }
> + return stack;
> +}
> +
> +/**
> + * update_var_state - Update type state using given variables
> + * @state: type state table
> + * @dloc: data location info
> + * @addr: instruction address to update
> + * @var_types: list of variables with type info
> + *
> + * This function fills the @state table using @var_types info. Each variable
> + * is used only at the given location and updates an entry in the table.
> + */
> +void update_var_state(struct type_state *state, struct data_loc_info *dloc,
> + u64 addr, struct die_var_type *var_types)
> +{
> + Dwarf_Die mem_die;
> + struct die_var_type *var;
> + int fbreg = dloc->fbreg;
> + int fb_offset = 0;
> +
> + if (dloc->fb_cfa) {
> + if (die_get_cfa(dloc->di->dbg, addr, &fbreg, &fb_offset) < 0)
> + fbreg = -1;
> + }
> +
> + for (var = var_types; var != NULL; var = var->next) {
> + if (var->addr != addr)
> + continue;
> + /* Get the type DIE using the offset */
> + if (!dwarf_offdie(dloc->di->dbg, var->die_off, &mem_die))
> + continue;
> +
> + if (var->reg == DWARF_REG_FB) {
> + findnew_stack_state(state, var->offset, &mem_die);
> + } else if (var->reg == fbreg) {
> + findnew_stack_state(state, var->offset - fb_offset, &mem_die);
> + } else if (has_reg_type(state, var->reg)) {
> + struct type_state_reg *reg;
> +
> + reg = &state->regs[var->reg];
> + reg->type = mem_die;
> + reg->ok = true;
> + }
> + }
> +}
> +
> /* The result will be saved in @type_die */
> static int find_data_type_die(struct data_loc_info *dloc, Dwarf_Die *type_die)
> {
> diff --git a/tools/perf/util/annotate-data.h b/tools/perf/util/annotate-data.h
> index ad6493ea2c8e..7fbb9eb2e96f 100644
> --- a/tools/perf/util/annotate-data.h
> +++ b/tools/perf/util/annotate-data.h
> @@ -8,9 +8,12 @@
> #include <linux/types.h>
>
> struct annotated_op_loc;
> +struct arch;
> struct debuginfo;
> +struct die_var_type;
> struct evsel;
> struct map_symbol;
> +struct type_state;
>
> /**
> * struct annotated_member - Type of member field
> @@ -146,6 +149,16 @@ int annotated_data_type__update_samples(struct annotated_data_type *adt,
> /* Release all data type information in the tree */
> void annotated_data_type__tree_delete(struct rb_root *root);
>
> +/* Initialize type state table */
> +void init_type_state(struct type_state *state, struct arch *arch);
> +
> +/* Destroy type state table */
> +void exit_type_state(struct type_state *state);
> +
> +/* Update type state table using variables */
> +void update_var_state(struct type_state *state, struct data_loc_info *dloc,
> + u64 addr, struct die_var_type *var_types);
> +
> #else /* HAVE_DWARF_SUPPORT */
>
> static inline struct annotated_data_type *
> @@ -168,6 +181,22 @@ static inline void annotated_data_type__tree_delete(struct rb_root *root __maybe
> {
> }
>
> +static inline void init_type_state(struct type_state *state __maybe_unused,
> + struct arch *arch __maybe_unused)
> +{
> +}
> +
> +static inline void exit_type_state(struct type_state *state __maybe_unused)
> +{
> +}
> +
> +static inline void update_var_state(struct type_state *state __maybe_unused,
> + struct data_loc_info *dloc __maybe_unused,
> + u64 addr __maybe_unused,
> + struct die_var_type *var_types __maybe_unused)
> +{
> +}
> +
> #endif /* HAVE_DWARF_SUPPORT */
>
> #endif /* _PERF_ANNOTATE_DATA_H */
> diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c
> index 39851ff1d5c4..f88a8fb4a350 100644
> --- a/tools/perf/util/dwarf-aux.c
> +++ b/tools/perf/util/dwarf-aux.c
> @@ -9,6 +9,7 @@
> #include <stdlib.h>
> #include "debug.h"
> #include "dwarf-aux.h"
> +#include "dwarf-regs.h"
> #include "strbuf.h"
> #include "string2.h"
>
> @@ -1147,6 +1148,8 @@ static int reg_from_dwarf_op(Dwarf_Op *op)
> case DW_OP_regx:
> case DW_OP_bregx:
> return op->number;
> + case DW_OP_fbreg:
> + return DWARF_REG_FB;
> default:
> break;
> }
> @@ -1160,6 +1163,7 @@ static int offset_from_dwarf_op(Dwarf_Op *op)
> case DW_OP_regx:
> return 0;
> case DW_OP_breg0 ... DW_OP_breg31:
> + case DW_OP_fbreg:
> return op->number;
> case DW_OP_bregx:
> return op->number2;
> --
> 2.43.0.594.gd9cf4e227d-goog
>
On Fri, Feb 2, 2024 at 6:45 PM Ian Rogers <irogers@google.com> wrote:
>
> On Fri, Feb 2, 2024 at 2:05 PM Namhyung Kim <namhyung@kernel.org> wrote:
> >
> > As it collected basic block and variable information in each scope, it
> > now can build a state table to find matching variable at the location.
> >
> > The struct type_state is to keep the type info saved in each register
> > and stack slot. The update_var_state() updates the table when it finds
> > variables in the current address. It expects die_collect_vars() filled
> > a list of variables with type info and starting address.
> >
> > Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> > ---
> > tools/perf/util/annotate-data.c | 155 ++++++++++++++++++++++++++++++++
> > tools/perf/util/annotate-data.h | 29 ++++++
> > tools/perf/util/dwarf-aux.c | 4 +
> > 3 files changed, 188 insertions(+)
> >
> > diff --git a/tools/perf/util/annotate-data.c b/tools/perf/util/annotate-data.c
> > index b8e60c42af8c..f8768c224bcc 100644
> > --- a/tools/perf/util/annotate-data.c
> > +++ b/tools/perf/util/annotate-data.c
> > @@ -23,6 +23,57 @@
> > #include "symbol.h"
> > #include "symbol_conf.h"
> >
> > +/* Type information in a register, valid when ok is true */
> > +struct type_state_reg {
> > + Dwarf_Die type;
> > + bool ok;
> > + bool scratch;
> > +};
> > +
> > +/* Type information in a stack location, dynamically allocated */
> > +struct type_state_stack {
> > + struct list_head list;
> > + Dwarf_Die type;
> > + int offset;
> > + int size;
> > + bool compound;
> > +};
> > +
> > +/* FIXME: This should be arch-dependent */
> > +#define TYPE_STATE_MAX_REGS 16
>
> Perhaps 32, presumably 16 won't work on Arm64.
Right, but right now I'm targeting x86_64 only.
Maybe we can change it later when it supports Arm64.
Thanks,
Namhyung
@@ -23,6 +23,57 @@
#include "symbol.h"
#include "symbol_conf.h"
+/* Type information in a register, valid when ok is true */
+struct type_state_reg {
+ Dwarf_Die type;
+ bool ok;
+ bool scratch;
+};
+
+/* Type information in a stack location, dynamically allocated */
+struct type_state_stack {
+ struct list_head list;
+ Dwarf_Die type;
+ int offset;
+ int size;
+ bool compound;
+};
+
+/* FIXME: This should be arch-dependent */
+#define TYPE_STATE_MAX_REGS 16
+
+/*
+ * State table to maintain type info in each register and stack location.
+ * It'll be updated when new variable is allocated or type info is moved
+ * to a new location (register or stack). As it'd be used with the
+ * shortest path of basic blocks, it only maintains a single table.
+ */
+struct type_state {
+ struct type_state_reg regs[TYPE_STATE_MAX_REGS];
+ struct list_head stack_vars;
+};
+
+static bool has_reg_type(struct type_state *state, int reg)
+{
+ return (unsigned)reg < ARRAY_SIZE(state->regs);
+}
+
+void init_type_state(struct type_state *state, struct arch *arch __maybe_unused)
+{
+ memset(state, 0, sizeof(*state));
+ INIT_LIST_HEAD(&state->stack_vars);
+}
+
+void exit_type_state(struct type_state *state)
+{
+ struct type_state_stack *stack, *tmp;
+
+ list_for_each_entry_safe(stack, tmp, &state->stack_vars, list) {
+ list_del(&stack->list);
+ free(stack);
+ }
+}
+
/*
* Compare type name and size to maintain them in a tree.
* I'm not sure if DWARF would have information of a single type in many
@@ -238,6 +289,110 @@ static int check_variable(Dwarf_Die *var_die, Dwarf_Die *type_die, int offset,
return 0;
}
+static struct type_state_stack *find_stack_state(struct type_state *state,
+ int offset)
+{
+ struct type_state_stack *stack;
+
+ list_for_each_entry(stack, &state->stack_vars, list) {
+ if (offset == stack->offset)
+ return stack;
+
+ if (stack->compound && stack->offset < offset &&
+ offset < stack->offset + stack->size)
+ return stack;
+ }
+ return NULL;
+}
+
+static void set_stack_state(struct type_state_stack *stack, int offset,
+ Dwarf_Die *type_die)
+{
+ int tag;
+ Dwarf_Word size;
+
+ if (dwarf_aggregate_size(type_die, &size) < 0)
+ size = 0;
+
+ tag = dwarf_tag(type_die);
+
+ stack->type = *type_die;
+ stack->size = size;
+ stack->offset = offset;
+
+ switch (tag) {
+ case DW_TAG_structure_type:
+ case DW_TAG_union_type:
+ stack->compound = true;
+ break;
+ default:
+ stack->compound = false;
+ break;
+ }
+}
+
+static struct type_state_stack *findnew_stack_state(struct type_state *state,
+ int offset, Dwarf_Die *type_die)
+{
+ struct type_state_stack *stack = find_stack_state(state, offset);
+
+ if (stack) {
+ set_stack_state(stack, offset, type_die);
+ return stack;
+ }
+
+ stack = malloc(sizeof(*stack));
+ if (stack) {
+ set_stack_state(stack, offset, type_die);
+ list_add(&stack->list, &state->stack_vars);
+ }
+ return stack;
+}
+
+/**
+ * update_var_state - Update type state using given variables
+ * @state: type state table
+ * @dloc: data location info
+ * @addr: instruction address to update
+ * @var_types: list of variables with type info
+ *
+ * This function fills the @state table using @var_types info. Each variable
+ * is used only at the given location and updates an entry in the table.
+ */
+void update_var_state(struct type_state *state, struct data_loc_info *dloc,
+ u64 addr, struct die_var_type *var_types)
+{
+ Dwarf_Die mem_die;
+ struct die_var_type *var;
+ int fbreg = dloc->fbreg;
+ int fb_offset = 0;
+
+ if (dloc->fb_cfa) {
+ if (die_get_cfa(dloc->di->dbg, addr, &fbreg, &fb_offset) < 0)
+ fbreg = -1;
+ }
+
+ for (var = var_types; var != NULL; var = var->next) {
+ if (var->addr != addr)
+ continue;
+ /* Get the type DIE using the offset */
+ if (!dwarf_offdie(dloc->di->dbg, var->die_off, &mem_die))
+ continue;
+
+ if (var->reg == DWARF_REG_FB) {
+ findnew_stack_state(state, var->offset, &mem_die);
+ } else if (var->reg == fbreg) {
+ findnew_stack_state(state, var->offset - fb_offset, &mem_die);
+ } else if (has_reg_type(state, var->reg)) {
+ struct type_state_reg *reg;
+
+ reg = &state->regs[var->reg];
+ reg->type = mem_die;
+ reg->ok = true;
+ }
+ }
+}
+
/* The result will be saved in @type_die */
static int find_data_type_die(struct data_loc_info *dloc, Dwarf_Die *type_die)
{
@@ -8,9 +8,12 @@
#include <linux/types.h>
struct annotated_op_loc;
+struct arch;
struct debuginfo;
+struct die_var_type;
struct evsel;
struct map_symbol;
+struct type_state;
/**
* struct annotated_member - Type of member field
@@ -146,6 +149,16 @@ int annotated_data_type__update_samples(struct annotated_data_type *adt,
/* Release all data type information in the tree */
void annotated_data_type__tree_delete(struct rb_root *root);
+/* Initialize type state table */
+void init_type_state(struct type_state *state, struct arch *arch);
+
+/* Destroy type state table */
+void exit_type_state(struct type_state *state);
+
+/* Update type state table using variables */
+void update_var_state(struct type_state *state, struct data_loc_info *dloc,
+ u64 addr, struct die_var_type *var_types);
+
#else /* HAVE_DWARF_SUPPORT */
static inline struct annotated_data_type *
@@ -168,6 +181,22 @@ static inline void annotated_data_type__tree_delete(struct rb_root *root __maybe
{
}
+static inline void init_type_state(struct type_state *state __maybe_unused,
+ struct arch *arch __maybe_unused)
+{
+}
+
+static inline void exit_type_state(struct type_state *state __maybe_unused)
+{
+}
+
+static inline void update_var_state(struct type_state *state __maybe_unused,
+ struct data_loc_info *dloc __maybe_unused,
+ u64 addr __maybe_unused,
+ struct die_var_type *var_types __maybe_unused)
+{
+}
+
#endif /* HAVE_DWARF_SUPPORT */
#endif /* _PERF_ANNOTATE_DATA_H */
@@ -9,6 +9,7 @@
#include <stdlib.h>
#include "debug.h"
#include "dwarf-aux.h"
+#include "dwarf-regs.h"
#include "strbuf.h"
#include "string2.h"
@@ -1147,6 +1148,8 @@ static int reg_from_dwarf_op(Dwarf_Op *op)
case DW_OP_regx:
case DW_OP_bregx:
return op->number;
+ case DW_OP_fbreg:
+ return DWARF_REG_FB;
default:
break;
}
@@ -1160,6 +1163,7 @@ static int offset_from_dwarf_op(Dwarf_Op *op)
case DW_OP_regx:
return 0;
case DW_OP_breg0 ... DW_OP_breg31:
+ case DW_OP_fbreg:
return op->number;
case DW_OP_bregx:
return op->number2;