lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Fri, 18 May 2012 09:09:13 -0400
From:	Steven Rostedt <rostedt@...dmis.org>
To:	linux-kernel@...r.kernel.org
Cc:	Ingo Molnar <mingo@...e.hu>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Frederic Weisbecker <fweisbec@...il.com>
Subject: [PATCH 15/15] ftrace: Remove selecting FRAME_POINTER with FUNCTION_TRACER

From: Steven Rostedt <srostedt@...hat.com>

The function tracer will enable the -pg option with gcc, which requires
that frame pointers. When FRAME_POINTER is defined in the kernel config
it adds the gcc option -fno-omit-frame-pointer which causes some problems
on some architectures. For those architectures, the FRAME_POINTER select
was not set.

When FUNCTION_TRACER was selected on these architectures that can not have
-fno-omit-frame-pointer, the -pg option is still set. But when
FRAME_POINTER is not selected, the kernel config would add the gcc option
-fomit-frame-pointer. Adding this option is incompatible with -pg
even on archs that do not need frame pointers with -pg.

The answer to this was to just not add either -fno-omit-frame-pointer
or -fomit-frame-pointer on these archs that want function tracing
but do not set FRAME_POINTER.

As it turns out, for archs that require frame pointers for function
tracing, the same can be used. If gcc requires frame pointers with
-pg, it will simply add it. The best thing to do is not select FRAME_POINTER
when function tracing is selected, and let gcc add it if needed.

Only add the -fno-omit-frame-pointer when something else selects
FRAME_POINTER, but do not add -fomit-frame-pointer if function tracing
is selected.

Signed-off-by: Steven Rostedt <rostedt@...dmis.org>
---
 kernel/trace/Kconfig |    1 -
 1 file changed, 1 deletion(-)

diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index a1d2849..d81a1a5 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -141,7 +141,6 @@ if FTRACE
 config FUNCTION_TRACER
 	bool "Kernel Function Tracer"
 	depends on HAVE_FUNCTION_TRACER
-	select FRAME_POINTER if !ARM_UNWIND && !PPC && !S390 && !MICROBLAZE
 	select KALLSYMS
 	select GENERIC_TRACER
 	select CONTEXT_SWITCH_TRACER
-- 
1.7.10



Download attachment "signature.asc" of type "application/pgp-signature" (837 bytes)

Powered by blists - more mailing lists