[PATCH] arch/tile: avoid generating .eh_frame information in modules

From: Chris Metcalf
Date: Fri Oct 19 2012 - 16:39:19 EST


The tile tool chain uses the .eh_frame information for backtracing.
The vmlinux build drops any .eh_frame sections at link time, but when
present in kernel modules, it causes a module load failure due to the
presence of unsupported pc-relative relocations. When compiling to
use compiler feedback support, the compiler by default omits .eh_frame
information, so we don't see this problem. But when not using feedback,
we need to explicitly suppress the .eh_frame.

Signed-off-by: Chris Metcalf <cmetcalf@xxxxxxxxxx>
---
arch/tile/Makefile | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/arch/tile/Makefile b/arch/tile/Makefile
index 55640cf..3d15364 100644
--- a/arch/tile/Makefile
+++ b/arch/tile/Makefile
@@ -26,6 +26,10 @@ $(error Set TILERA_ROOT or CROSS_COMPILE when building $(ARCH) on $(HOST_ARCH))
endif
endif

+# The tile compiler may emit .eh_frame information for backtracing.
+# In kernel modules, this causes load failures due to unsupported relocations.
+KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
+
ifneq ($(CONFIG_DEBUG_EXTRA_FLAGS),"")
KBUILD_CFLAGS += $(CONFIG_DEBUG_EXTRA_FLAGS)
endif
--
1.7.10.3

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