[tip:tracing/urgent] ftrace: Only update $offset when we update $ref_func

tip-bot for Matt Fleming
2009-08-04T08:11:06Z

Commit-ID: bd171d5ffc5cb2ba471e8205c679ee9d12b90116
Gitweb: http://git.kernel.org/tip/bd171d5ffc5cb2ba471e8205c679ee9d12b90116
Author: Matt Fleming <matt@console-pimps.org>
AuthorDate: Thu, 23 Jul 2009 17:16:15 +0100
Committer: Steven Rostedt <rostedt@goodmis.org>
CommitDate: Thu, 23 Jul 2009 12:20:30 -0400

ftrace: Only update $offset when we update $ref_func

The value of $offset should be the offset of $ref_func from the
beginning of the object file. Therefore, we should set both variables
together.

This fixes a bug I was hitting on sh where $offset (which is used to
calcualte the addends for the __mcount_loc entries) was being set
multiple times and didn't correspond to $ref_func's offset in the object
file. The addends in __mcount_loc were calculated incorrectly, resulting
in ftrace dynamically modifying addresses that weren't mcount call
sites.

Signed-off-by: Matt Fleming <matt@console-pimps.org>
LKML-Reference: <1248365775-25196-2-git-send-email-matt@console-pimps.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

---
scripts/recordmcount.pl | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/scripts/recordmcount.pl b/scripts/recordmcount.pl
index 16c5563..d29baa2 100755
--- a/scripts/recordmcount.pl
+++ b/scripts/recordmcount.pl
@@ -403,7 +403,6 @@ while (<IN>) {
# section found, now is this a start of a function?
} elsif ($read_function && /$function_regex/) {
$text_found = 1;
- $offset = hex $1;
$text = $2;

# if this is either a local function or a weak function
@@ -412,10 +411,12 @@ while (<IN>) {
if (!defined($locals{$text}) && !defined($weak{$text})) {
$ref_func = $text;
$read_function = 0;
+ $offset = hex $1;
} else {
# if we already have a function, and this is weak, skip it
if (!defined($ref_func) && !defined($weak{$text})) {
$ref_func = $text;
+ $offset = hex $1;
}
}
} elsif ($read_headers && /$mcount_section/) {