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Date:   Mon, 27 Jan 2020 11:35:49 -0800
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Subject: [RFC v1 2/2] arch: um: turn BTF_TYPEINFO support off
From:   Brendan Higgins <brendanhiggins@google.com>
To:     jdike@addtoit.com, richard@nod.at, anton.ivanov@cambridgegreys.com,
        akpm@linux-foundation.org, changbin.du@intel.com,
        yamada.masahiro@socionext.com, rdunlap@infradead.org,
        keescook@chromium.org, andriy.shevchenko@linux.intel.com
Cc:     linux-um@lists.infradead.org, linux-kernel@vger.kernel.org,
        davidgow@google.com, heidifahim@google.com,
        Brendan Higgins <brendanhiggins@google.com>
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Sender: linux-kernel-owner@vger.kernel.org
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Currently CONFIG_DEBUG_INFO_BTF=y doesn't work on UML:

scripts/link-vmlinux.sh: line 106: 17463 Segmentation fault      LLVM_OBJCOPY=${OBJCOPY} ${PAHOLE} -J ${1}
objcopy: --change-section-vma .BTF=0x0000000000000000 never used
objcopy: --change-section-lma .BTF=0x0000000000000000 never used
objcopy: error: the input file '.btf.vmlinux.bin' is empty
Failed to generate BTF for vmlinux
Try to disable CONFIG_DEBUG_INFO_BTF
make: *** [Makefile:1078: vmlinux] Error 1

So turn off ARCH_HAS_BTF_TYPEINFO support off for the UM architecture.

Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
---
 arch/um/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/um/Kconfig b/arch/um/Kconfig
index 0917f8443c285..53e13d8b210e0 100644
--- a/arch/um/Kconfig
+++ b/arch/um/Kconfig
@@ -6,6 +6,7 @@ config UML
 	bool
 	default y
 	select ARCH_HAS_KCOV
+	select ARCH_NO_BTF_TYPEINFO
 	select ARCH_NO_PREEMPT
 	select HAVE_ARCH_AUDITSYSCALL
 	select HAVE_ARCH_SECCOMP_FILTER
-- 
2.25.0.341.g760bfbb309-goog