Re: [PATCH v4 05/15] perf report: create real callchain entries for inlined frames

Namhyung Kim
2017-10-05T03:38:09Z

On Sun, Oct 01, 2017 at 04:30:50PM +0200, Milian Wolff wrote:
> The inline_node structs are maintained by the new dso->inlines
> tree. This in turn keeps ownership of the fake symbols and
> srcline string representing an inline frame.
>
> This tree is always sorted by name. All other entries of the symbol

Isn't it sorted by address?

> beside the function name are unused for inline frames. The advantage
> of this approach is that all existing users of the callchain API can
> now transparently display inlined frames without having to patch
> their code.
>
> Cc: Jiri Olsa <jolsa@redhat.com>
> Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
> Cc: David Ahern <dsahern@gmail.com>
> Cc: Namhyung Kim <namhyung@kernel.org>
> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
> Cc: Yao Jin <yao.jin@linux.intel.com>
> Signed-off-by: Milian Wolff <milian.wolff@kdab.com>
> ---
> tools/perf/util/dso.c | 3 +++
> tools/perf/util/dso.h | 1 +
> tools/perf/util/machine.c | 37 ++++++++++++++++++++++++++++++++++
> tools/perf/util/srcline.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++
> tools/perf/util/srcline.h | 9 +++++++++
> 5 files changed, 101 insertions(+)
>
> diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
> index 339e52971380..6e743dffc487 100644
> --- a/tools/perf/util/dso.c
> +++ b/tools/perf/util/dso.c
> @@ -10,6 +10,7 @@
> #include "compress.h"
> #include "path.h"
> #include "symbol.h"
> +#include "srcline.h"
> #include "dso.h"
> #include "machine.h"
> #include "auxtrace.h"
> @@ -1201,6 +1202,7 @@ struct dso *dso__new(const char *name)
> for (i = 0; i < MAP__NR_TYPES; ++i)
> dso->symbols[i] = dso->symbol_names[i] = RB_ROOT;
> dso->data.cache = RB_ROOT;
> + dso->inlined_nodes = RB_ROOT;
> dso->data.fd = -1;
> dso->data.status = DSO_DATA_STATUS_UNKNOWN;
> dso->symtab_type = DSO_BINARY_TYPE__NOT_FOUND;
> @@ -1234,6 +1236,7 @@ void dso__delete(struct dso *dso)
> dso->long_name);
> for (i = 0; i < MAP__NR_TYPES; ++i)
> symbols__delete(&dso->symbols[i]);
> + inlines__tree_delete(&dso->inlined_nodes);

I'm still curious why it doesn't make a trouble (I think there's
use-after-free for non-inlined symbols). Anyway moving the
inlines__tree_delete() above the symbols__delete() will solve the
concern IMHO.

Thanks,
Namhyung

>
> if (dso->short_name_allocated) {
> zfree((char **)&dso->short_name);

[SNIP]

> diff --git a/tools/perf/util/srcline.c b/tools/perf/util/srcline.c
> index 07d1a058d7c4..69241d805275 100644
> --- a/tools/perf/util/srcline.c
> +++ b/tools/perf/util/srcline.c
> @@ -583,3 +583,54 @@ void inline_node__delete(struct inline_node *node)
>
> free(node);
> }
> +
> +void inlines__tree_insert(struct rb_root *tree, struct inline_node *inlines)
> +{
> + struct rb_node **p = &tree->rb_node;
> + struct rb_node *parent = NULL;
> + const u64 addr = inlines->addr;
> + struct inline_node *i;
> +
> + while (*p != NULL) {
> + parent = *p;
> + i = rb_entry(parent, struct inline_node, rb_node);
> + if (addr < i->addr)
> + p = &(*p)->rb_left;
> + else
> + p = &(*p)->rb_right;
> + }
> + rb_link_node(&inlines->rb_node, parent, p);
> + rb_insert_color(&inlines->rb_node, tree);
> +}
> +
> +struct inline_node *inlines__tree_find(struct rb_root *tree, u64 addr)
> +{
> + struct rb_node *n = tree->rb_node;
> +
> + while (n) {
> + struct inline_node *i = rb_entry(n, struct inline_node,
> + rb_node);
> +
> + if (addr < i->addr)
> + n = n->rb_left;
> + else if (addr > i->addr)
> + n = n->rb_right;
> + else
> + return i;
> + }
> +
> + return NULL;
> +}
> +
> +void inlines__tree_delete(struct rb_root *tree)
> +{
> + struct inline_node *pos;
> + struct rb_node *next = rb_first(tree);
> +
> + while (next) {
> + pos = rb_entry(next, struct inline_node, rb_node);
> + next = rb_next(&pos->rb_node);
> + rb_erase(&pos->rb_node, tree);
> + inline_node__delete(pos);
> + }
> +}
> diff --git a/tools/perf/util/srcline.h b/tools/perf/util/srcline.h
> index 0201ed2c0b9c..ebe38cd22294 100644
> --- a/tools/perf/util/srcline.h
> +++ b/tools/perf/util/srcline.h
> @@ -2,6 +2,7 @@
> #define PERF_SRCLINE_H
>
> #include <linux/list.h>
> +#include <linux/rbtree.h>
> #include <linux/types.h>
>
> struct dso;
> @@ -25,6 +26,7 @@ struct inline_list {
> struct inline_node {
> u64 addr;
> struct list_head val;
> + struct rb_node rb_node;
> };
>
> /* parse inlined frames for the given address */
> @@ -33,4 +35,11 @@ struct inline_node *dso__parse_addr_inlines(struct dso *dso, u64 addr,
> /* free resources associated to the inline node list */
> void inline_node__delete(struct inline_node *node);
>
> +/* insert the inline node list into the DSO, which will take ownership */
> +void inlines__tree_insert(struct rb_root *tree, struct inline_node *inlines);
> +/* find previously inserted inline node list */
> +struct inline_node *inlines__tree_find(struct rb_root *tree, u64 addr);
> +/* delete all nodes within the tree of inline_node s */
> +void inlines__tree_delete(struct rb_root *tree);
> +
> #endif /* PERF_SRCLINE_H */
> --
> 2.14.2
>