Messages in this thread Patch in this message |  | | From | Masami Hiramatsu <> | Subject | [RFC][ PATCH -tip v2 3/7] Kbuild: disable gcc crossjumping | Date | Mon, 22 Jun 2009 17:23:13 -0400 |
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Add CONFIG_DISABLE_CROSSJUMP option which disables gcc's cross-function jumping. This option is required by the kprobes jump optimization.
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Anders Kaseorg <andersk@ksplice.com> Cc: Tim Abbott <tabbott@ksplice.com> ---
Makefile | 4 ++++ lib/Kconfig.debug | 7 +++++++ 2 files changed, 11 insertions(+), 0 deletions(-)
diff --git a/Makefile b/Makefile index 2903e13..f73b139 100644 --- a/Makefile +++ b/Makefile @@ -524,6 +524,10 @@ else KBUILD_CFLAGS += -O2 endif +ifdef CONFIG_DISABLE_CROSSJUMP +KBUILD_CFLAGS += -fno-crossjumping +endif + include $(srctree)/arch/$(SRCARCH)/Makefile ifneq ($(CONFIG_FRAME_WARN),0) diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 8da7467..f88e6b8 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -673,6 +673,13 @@ config FRAME_POINTER larger and slower, but it gives very useful debugging information in case of kernel bugs. (precise oopses/stacktraces/warnings) +config DISABLE_CROSSJUMP + bool "Disable cross-function jump optimization" + help + This build option disables cross-function jump optimization + (crossjumping) of gcc. Disabling crossjumping might increase + kernel binary size a little. + config BOOT_PRINTK_DELAY bool "Delay each boot printk message by N milliseconds" depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
-- Masami Hiramatsu
Software Engineer Hitachi Computer Products (America), Inc. Software Solutions Division
e-mail: mhiramat@redhat.com
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