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From: Yonghong Song <yhs@fb.com>
To: "bpf@vger.kernel.org" <bpf@vger.kernel.org>
Cc: Andrii Nakryiko <andriin@fb.com>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Alexei Starovoitov <ast@fb.com>
Subject: headsup: latest llvm breaks libbpf/selftests
Date: Wed, 15 Jan 2020 05:58:04 +0000	[thread overview]
Message-ID: <18b7e7a4-dd3c-6e1b-c410-3b876320da97@fb.com> (raw)

Hi,

The LLVM patch https://reviews.llvm.org/D72197, which is merged to llvm 
trunk on Sunday (01/12), emitted function call relocations within the
same section. This breaks libbpf and selftests as libbpf assumes no same
section relocations.

To work around the issue, after you pull in latest llvm, just checkout
the commit before the following one:
    commit 2bfee35cb860859b436de0b780fbd00d68e198a4
    Author: Fangrui Song <maskray@google.com>
    Date:   Fri Jan 3 21:44:57 2020 -0800

    [MC][ELF] Emit a relocation if target is defined in the same section
    and is non-local

...
ada22c804cd956f3ee7cc9dc82e6d54ead8a4ffe Fix "pointer is null" static 
analyzer warning. NFCI.
2bfee35cb860859b436de0b780fbd00d68e198a4 [MC][ELF] Emit a relocation if 
target is defined in the same section and is non-local
241f330d6bab52ab4e3a01cbb9a3edd417d07c59 [AMDGPU] Add gfx8 assembler and 
disassembler test cases
    ^^^^^^
    checkout this commit
7fa5290d5bd5632d7a36a4ea9f46e81e04fb819e __patchable_function_entries: 
don't use linkage field 'unique' with -no-integrated-as
...

libbpf and selftests should work again.

The issue will be addressed soon.

Thanks,

Yonghong

                 reply	other threads:[~2020-01-15  5:58 UTC|newest]

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