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From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar <mingo@elte.hu>,
	Andrew Morton <akpm@linux-foundation.org>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Li Hong <lihong.hi@gmail.com>
Subject: [PATCH 8/8] [PATCH 8/8] tracing: Exit with error if a weak function is used in recordmcount.pl
Date: Thu, 29 Oct 2009 18:33:02 -0400	[thread overview]
Message-ID: <20091029223321.033537042@goodmis.org> (raw)
In-Reply-To: 20091029223254.504427063@goodmis.org

[-- Attachment #1: 0008-tracing-Exit-with-error-if-a-weak-function-is-used-i.patch --]
[-- Type: text/plain, Size: 1501 bytes --]

From: Li Hong <lihong.hi@gmail.com>

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@gmail.com>
LKML-Reference: <20091028050743.GH30758@uhli>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 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



  parent reply	other threads:[~2009-10-29 22:33 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-10-29 22:32 [PATCH 0/8] tracing: fixes and cleanups for recordmcount.pl Steven Rostedt
2009-10-29 22:32 ` [PATCH 1/8] [PATCH 1/8] tracing: Amend documentation in recordmcount.pl to reflect implementation Steven Rostedt
2009-10-29 22:32 ` [PATCH 2/8] [PATCH 2/8] tracing: Correct the check for number of arguments in recordmcount.pl Steven Rostedt
2009-10-29 22:32 ` [PATCH 3/8] [PATCH 3/8] tracing: Check absolute path of input file " Steven Rostedt
2009-10-29 22:32 ` [PATCH 4/8] [PATCH 4/8] tracing: Fix objcopy revision check " Steven Rostedt
2009-10-29 22:32 ` [PATCH 5/8] [PATCH 5/8] tracing: Move mcount section search to front of loop " Steven Rostedt
2009-10-29 22:33 ` [PATCH 6/8] [PATCH 6/8] tracing: Add regex for weak functions " Steven Rostedt
2009-10-29 22:33 ` [PATCH 7/8] [PATCH 7/8] tracing: Move conditional into update_funcs() " Steven Rostedt
2009-10-29 22:33 ` Steven Rostedt [this message]
2009-10-30  7:45 ` [PATCH 0/8] tracing: fixes and cleanups for recordmcount.pl Ingo Molnar

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