Re: 'perf test' failed on ARM

[Rabin Vincent <rabin@rab.in>]

On Tue, Nov 23, 2010 at 04:07:39PM +0800, Ming Lei wrote:
> 'perf test' is failed on linux 2.6.37-rc2/rc3, follows log info:
> 
> root@beagleboard:/mnt/omap/linux-2.6-omap/tools/perf# ./perf test -v 3
>  1: vmlinux symtab matches kallsyms:
> --- start ---
> dso__find_symbol_by_name ---- end ----
> vmlinux symtab matches kallsyms: FAILED!
> 
> Any suggestions?

There seems to be a problem with the symbol handling code.  Patch below.
With this patch the command executes further, but the test fails because
of other reasons:

   1: vmlinux symtab matches kallsyms:
  --- start ---
  map_groups__set_modules_path_dir: cannot open /lib/modules/2.6.37-rc3-next-20101122+/kernel dir
  Problems creating module maps, continuing anyway...
  map_groups__set_modules_path_dir: cannot open /lib/modules/2.6.37-rc3-next-20101122+/kernel dir
  Problems creating module maps, continuing anyway...
  Looking at the vmlinux_path (6 entries long)
  Using vmlinux for symbols
  0xc011ab68: diff end addr for __kprobes_text_start v: 0xc012b87f k: 0xc011b353
  0xc012b880: kallsyms_addresses not on kallsyms
  0xc0138c90: kallsyms_num_syms not on kallsyms
  0xc0138ca0: kallsyms_names not on kallsyms
  0xc015c010: kallsyms_markers not on kallsyms
  0xc015c0f0: kallsyms_token_table not on kallsyms
  0xc015c490: kallsyms_token_index not on kallsyms
  Maps only in vmlinux:
   c0014c5c-ffffffff 0 [kernel].init
  Maps in vmlinux with a different name in kallsyms:
  Maps only in kallsyms:
  ---- end ----
  vmlinux symtab matches kallsyms: FAILED!

>From e48b8a0dc149e3b8f249f46dc6e9c25e2cc58601 Mon Sep 17 00:00:00 2001
From: Rabin Vincent <rabin@rab.in>
Date: Tue, 23 Nov 2010 21:35:56 +0530
Subject: [PATCH] perf symbols: remove incorrect open-coded container_of()

At least on ARM, padding is inserted between rb_node and sym in struct
symbol_name_rb_node, causing "((void *)sym) - sizeof(struct rb_node)" to
point inside rb_node rather than to the symbol_name_rb_node.  Fix this
by converting the code to use container_of().

Signed-off-by: Rabin Vincent <rabin@rab.in>
---
 tools/perf/util/symbol.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index b39f499..0500895 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -295,7 +295,9 @@ static void symbols__insert_by_name(struct rb_root *self, struct symbol *sym)
 {
 	struct rb_node **p = &self->rb_node;
 	struct rb_node *parent = NULL;
-	struct symbol_name_rb_node *symn = ((void *)sym) - sizeof(*parent), *s;
+	struct symbol_name_rb_node *symn, *s;
+
+	symn = container_of(sym, struct symbol_name_rb_node, sym);
 
 	while (*p != NULL) {
 		parent = *p;
-- 
1.7.2.3