[PATCH 8/8] [PATCH 8/8] tracing: Exit with error if a weak function is used in recordmcount.pl

From: Steven Rostedt
Date: Thu Oct 29 2009 - 18:33:32 EST


From: Li Hong <lihong.hi@xxxxxxxxx>

If a weak function is used as a relocation reference for mcount callers
and that function is overridden, it will cause ftrace to fail at run time.

The current code should prevent a weak function from being used, but if
one is, the code should exit with an error to fail at compile time.

Signed-off-by: Li Hong <lihong.hi@xxxxxxxxx>
LKML-Reference: <20091028050743.GH30758@uhli>
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
---
scripts/recordmcount.pl | 10 +++-------
1 files changed, 3 insertions(+), 7 deletions(-)

diff --git a/scripts/recordmcount.pl b/scripts/recordmcount.pl
index 884776a..a4e2435 100755
--- a/scripts/recordmcount.pl
+++ b/scripts/recordmcount.pl
@@ -350,15 +350,11 @@ sub update_funcs
{
return unless ($ref_func and @offsets);

- # A section only had a weak function, to represent it.
- # Unfortunately, a weak function may be overwritten by another
- # function of the same name, making all these offsets incorrect.
- # To be safe, we simply print a warning and bail.
+ # Sanity check on weak function. A weak function may be overwritten by
+ # another function of the same name, making all these offsets incorrect.
if (defined $weak{$ref_func}) {
- print STDERR
- "$inputfile: WARNING: referencing weak function" .
+ die "$inputfile: ERROR: referencing weak function" .
" $ref_func for mcount\n";
- return;
}

# is this function static? If so, note this fact.
--
1.6.3.3


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