From: Youling Tang <tangyouling@loongson.cn>
To: Xi Ruoyao <xry111@xry111.site>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Huacai Chen <chenhuacai@kernel.org>,
madvenka@linux.microsoft.com, chenzhongjin@huawei.com,
WANG Xuerui <kernel@xen0n.name>,
live-patching@vger.kernel.org, linux-kernel@vger.kernel.org,
loongarch@lists.linux.dev, tangyouling00@gmail.com,
youling.tang@outlook.com
Subject: Re: [RFC PATCH v1 00/23] LoongArch: Add objtool and ORC unwinder support
Date: Tue, 20 Jun 2023 16:29:12 +0800 [thread overview]
Message-ID: <62d25870-2caa-18ab-e58c-cee0bc383e16@loongson.cn> (raw)
In-Reply-To: <bed4d386c16701d14a2ea395edeb0368cb3d04ad.camel@xry111.site>
Hi, Ruoyao
On 06/20/2023 04:15 PM, Xi Ruoyao wrote:
> It looks like only 19 patches are successfully delivered, out of 23.
I'm sorry, somehow the patchset didn't reach the mailing list. Probably
due to the sending limit being reached.
>
> And AFAIK objtool needs libelf from elfutils, and the LoongArch support
> in elfutils is not complete (there are about ten failures in the test
> suite as at the latest 0.189 release). Do we need to add more LoongArch
> support into libelf and/or declare a minimal needed libelf version for
> LoongArch objtool?
After the following series of patches [1], the elfutils test results
are passed.
[1]: https://sourceware.org/pipermail/elfutils-devel/2023q2/006107.html
Thanks,
Youling
>
> On Tue, 2023-06-20 at 15:46 +0800, Youling Tang wrote:
>> This series of patches adds objtool and ORC unwinder support for
>> LoongArch.
>>
>> Patch 01 - 07 are from "Madhavan T. Venkataraman" [1] with minor
>> code tweaks. The "objtool: Reorganize ORC types" patch was not
>> added, because LoongArch cannot share `strcut orc_entry`, it also
>> needs to include ra_offset and ra_reg.
>>
>> Since the changes in Patch 01 - 08 in [1] are architecture-
>> independent,
>> it might be better if they could be separated separately from the
>> series
>> of patches.
>>
>> ORC unwinder can get a reliable stack trace, which provides a
>> prerequisite
>> for the subsequent addition of livepatch support.
>>
>>
>> Instruction decoder
>> ===================
>>
>> To do this, an instruction decoder needs to be implemented. I have
>> implemented
>> a simple, table-driven decoder for LoongArch. Only a subset of the
>> instructions
>> needs to be fully decoded for this purpose:
>>
>> - Load-Store instructions
>> - Add instructions
>> - Branch instructions
>> - Call instructions
>> - Return instructions
>> - Stack pointer authentication instruction
>>
>>
>> Unwind hints
>> ============
>>
>> Unwind hints are collected in a special section. Objtool converts
>> unwind hints
>> to ORC data. The unwinder processes unwind hints to handle special
>> cases
>> mentioned above.
>>
>>
>> ORC unwinder
>> ============
>>
>> Before vmlinux created, we check all metadata, find the stack
>> operation,
>> note stack state and create orc data. Objtool insert two sections into
>> vmlinux. '.orc_unwind_ip' and '.orc_unwind'. (For modules, insert
>> '.rela.orc_unwind_ip' to relocate '.orc_unwind_ip'.) Each insn has
>> only
>> one stack state in .orc_unwind and orc_unwind_ip hint its pc address.
>> Through unwinding orc data, we can get stack info both kernel and
>> module.
>>
>>
>> This is a series of RFC patches, which may require long-term
>> discussions
>> and revisions. It is not based on the latest code but based on 6.3-
>> rc3.
>> Any ideas or suggestions are welcome.
>>
>> base-commit: e8d018dd0257f744ca50a729e3d042cf2ec9da65 (Linux 6.3-rc3)
>>
>> Link:
>> [1]:
>> https://lore.kernel.org/lkml/20230202074036.507249-1-madvenka@linux.microsoft.com/#r
>>
>> Madhavan T. Venkataraman (7):
>> objtool: Reorganize CFI code
>> objtool: Reorganize instruction-related code
>> objtool: Move decode_instructions() to a separate file
>> objtool: Reorganize Unwind hint code
>> objtool: Reorganize ORC code
>> objtool: Reorganize ORC kernel code
>> objtool: Introduce STATIC_CHECK
>>
>> Youling Tang (16):
>> tools: LoongArch: Copy inst.h and asm.h to tools
>> objtool: LoongArch: Add base definition for LoongArch
>> objtool: LoongArch: Implement decoder
>> objtool: Add annotate_reachable() for objtools
>> LoongArch: bug: Add reachable annotation to warning macros
>> objtool: Add next member in struct reloc
>> objtool: Add orc_print_dump() package
>> objtool: Add ORC support for LoongArch
>> LoongArch: Add ORC unwinder support
>> LoongArch: Support R_LARCH_32_PCREL relocation type in kernel module
>> LoongArch: Fix fpu.S objtool warning
>> LoongArch: Annotate unwind_hint
>> LoongArch: Move some data definitions into the .data section
>> objtool: Add arch-specific "noreturn" function handling
>> objtool: Make update_cfi_state() arch-specific function
>> LoongArch: objtool: Mark non-standard object files and directories
>>
>> arch/loongarch/Kconfig | 2 +
>> arch/loongarch/Kconfig.debug | 11 +
>> arch/loongarch/Makefile | 4 +
>> arch/loongarch/include/asm/bug.h | 1 +
>> arch/loongarch/include/asm/module.h | 7 +
>> arch/loongarch/include/asm/orc_types.h | 58 ++
>> arch/loongarch/include/asm/stackframe.h | 3 +
>> arch/loongarch/include/asm/unwind.h | 17 +-
>> arch/loongarch/include/asm/unwind_hints.h | 110 +++
>> arch/loongarch/kernel/Makefile | 3 +
>> arch/loongarch/kernel/entry.S | 2 +
>> arch/loongarch/kernel/fpu.S | 11 +-
>> arch/loongarch/kernel/genex.S | 2 +
>> arch/loongarch/kernel/head.S | 1 +
>> arch/loongarch/kernel/module.c | 21 +-
>> arch/loongarch/kernel/relocate_kernel.S | 12 +-
>> arch/loongarch/kernel/setup.c | 2 +
>> arch/loongarch/kernel/stacktrace.c | 1 +
>> arch/loongarch/kernel/unwind_orc.c | 301 +++++++++
>> arch/loongarch/kernel/vmlinux.lds.S | 3 +
>> arch/loongarch/power/Makefile | 2 +
>> arch/loongarch/vdso/Makefile | 2 +
>> arch/x86/include/asm/unwind.h | 5 -
>> arch/x86/include/asm/unwind_hints.h | 86 +++
>> arch/x86/kernel/module.c | 7 +-
>> arch/x86/kernel/unwind_orc.c | 268 +-------
>> arch/x86/kernel/vmlinux.lds.S | 2 +-
>> .../asm => include/asm-generic}/orc_lookup.h | 43 ++
>> include/linux/compiler.h | 9 +
>> include/linux/objtool.h | 70 --
>> kernel/Makefile | 2 +
>> kernel/orc_lookup.c | 261 ++++++++
>> scripts/Makefile | 5 +-
>> tools/arch/loongarch/include/asm/asm.h | 201 ++++++
>> tools/arch/loongarch/include/asm/inst.h | 629
>> ++++++++++++++++++
>> tools/arch/loongarch/include/asm/orc_types.h | 58 ++
>> .../arch/loongarch/include/asm/unwind_hints.h | 110 +++
>> tools/arch/x86/include/asm/unwind_hints.h | 160 +++++
>> tools/include/linux/bitops.h | 10 +
>> tools/include/linux/objtool.h | 70 --
>> tools/objtool/Build | 8 +-
>> tools/objtool/Makefile | 9 +-
>> tools/objtool/arch/loongarch/Build | 3 +
>> tools/objtool/arch/loongarch/decode.c | 352 ++++++++++
>> .../arch/loongarch/include/arch/cfi_regs.h | 14 +
>> .../objtool/arch/loongarch/include/arch/elf.h | 15 +
>> .../arch/loongarch/include/arch/special.h | 21 +
>> tools/objtool/arch/loongarch/orc.c | 155 +++++
>> tools/objtool/arch/loongarch/special.c | 25 +
>> tools/objtool/arch/powerpc/special.c | 3 +
>> tools/objtool/arch/x86/Build | 1 +
>> tools/objtool/arch/x86/include/arch/elf.h | 1 +
>> tools/objtool/arch/x86/orc.c | 164 +++++
>> tools/objtool/arch/x86/special.c | 4 +
>> tools/objtool/cfi.c | 108 +++
>> tools/objtool/check.c | 568 +---------------
>> tools/objtool/decode.c | 136 ++++
>> tools/objtool/elf.c | 11 +-
>> tools/objtool/include/objtool/arch.h | 3 +
>> tools/objtool/include/objtool/cfi.h | 12 +
>> tools/objtool/include/objtool/check.h | 97 +--
>> tools/objtool/include/objtool/elf.h | 1 +
>> tools/objtool/include/objtool/insn.h | 166 +++++
>> tools/objtool/include/objtool/objtool.h | 3 +
>> tools/objtool/include/objtool/orc.h | 15 +
>> tools/objtool/include/objtool/special.h | 3 +
>> tools/objtool/insn.c | 195 ++++++
>> tools/objtool/orc_dump.c | 67 +-
>> tools/objtool/orc_gen.c | 79 +--
>> tools/objtool/sync-check.sh | 9 +
>> tools/objtool/unwind_hints.c | 107 +++
>> 71 files changed, 3721 insertions(+), 1206 deletions(-)
>> create mode 100644 arch/loongarch/include/asm/orc_types.h
>> create mode 100644 arch/loongarch/include/asm/unwind_hints.h
>> create mode 100644 arch/loongarch/kernel/unwind_orc.c
>> rename {arch/x86/include/asm => include/asm-generic}/orc_lookup.h
>> (50%)
>> create mode 100644 kernel/orc_lookup.c
>> create mode 100644 tools/arch/loongarch/include/asm/asm.h
>> create mode 100644 tools/arch/loongarch/include/asm/inst.h
>> create mode 100644 tools/arch/loongarch/include/asm/orc_types.h
>> create mode 100644 tools/arch/loongarch/include/asm/unwind_hints.h
>> create mode 100644 tools/arch/x86/include/asm/unwind_hints.h
>> create mode 100644 tools/objtool/arch/loongarch/Build
>> create mode 100644 tools/objtool/arch/loongarch/decode.c
>> create mode 100644
>> tools/objtool/arch/loongarch/include/arch/cfi_regs.h
>> create mode 100644 tools/objtool/arch/loongarch/include/arch/elf.h
>> create mode 100644
>> tools/objtool/arch/loongarch/include/arch/special.h
>> create mode 100644 tools/objtool/arch/loongarch/orc.c
>> create mode 100644 tools/objtool/arch/loongarch/special.c
>> create mode 100644 tools/objtool/arch/x86/orc.c
>> create mode 100644 tools/objtool/cfi.c
>> create mode 100644 tools/objtool/decode.c
>> create mode 100644 tools/objtool/include/objtool/insn.h
>> create mode 100644 tools/objtool/include/objtool/orc.h
>> create mode 100644 tools/objtool/insn.c
>> create mode 100644 tools/objtool/unwind_hints.c
>>
>
next prev parent reply other threads:[~2023-06-20 8:29 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-20 7:46 [RFC PATCH v1 00/23] LoongArch: Add objtool and ORC unwinder support Youling Tang
2023-06-20 7:46 ` [RFC PATCH v1 01/23] objtool: Reorganize CFI code Youling Tang
2023-06-20 7:46 ` [RFC PATCH v1 02/23] objtool: Reorganize instruction-related code Youling Tang
2023-06-20 7:46 ` [RFC PATCH v1 03/23] objtool: Move decode_instructions() to a separate file Youling Tang
2023-06-20 7:46 ` [RFC PATCH v1 04/23] objtool: Reorganize Unwind hint code Youling Tang
2023-06-20 8:15 ` [RFC PATCH v1 00/23] LoongArch: Add objtool and ORC unwinder support Xi Ruoyao
2023-06-20 8:29 ` Youling Tang [this message]
2023-06-20 8:32 ` Xi Ruoyao
2023-06-20 8:38 ` Peter Zijlstra
2023-06-20 8:48 ` Xi Ruoyao
2023-06-20 8:49 ` Youling Tang
2023-06-20 8:42 ` Peter Zijlstra
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