From: Julien Thierry <jthierry@redhat.com> To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: catalin.marinas@arm.com, will@kernel.org, ardb@kernel.org, masahiroy@kernel.org, keescook@chromium.org, michal.lkml@markovi.net, jpoimboe@redhat.com, peterz@infradead.org, mark.rutland@arm.com, broonie@kernel.org, linux-efi@vger.kernel.org, linux-hardening@vger.kernel.org, Julien Thierry <jthierry@redhat.com> Subject: [RFC PATCH 00/17] objtool: add base support for arm64 Date: Wed, 20 Jan 2021 18:37:43 +0100 [thread overview] Message-ID: <20210120173800.1660730-1-jthierry@redhat.com> (raw) Hi, This series enables objtool to start doing stack validation on arm64 kernel builds. It relies on the previous series I sent, refactoring the arm64 decoder [1]. First, the aarch64 instruction decoder needed to be made available to code under tools/. This is done in a similar manner to x86 instruction decoded. One limitation I encountered there is that most of aarch64 instruction decoder is __kprobe annotated. To bypass that it remove the kprobe include and had to add an empty __kprobe definition, but I'd welcome a proper solution to that. Then instruction semantics are progressively added so objtool can track the stack state through the execution flow. There are a few things that needed consideration: - Generation of constants within executable sections, these either caused objtool to fail decoding or to wrongly decode constants as jumps or other instructions affecting execution flow and causing confusion. To solve this, tracking locations referenced by instructions using literals was needed. - Jump tables from switch statements in aarch64 don't have enough information to link branches with the branch instruction leading to them. For this, we use a gcc plugin to add some information to establish those missing links in a format that is already supported by objtool With this, there are still some errors when building with objtool. A number of cleanups/annotations are needed on the arm64, as well as handling SYM_DATA objects in objtool. Those changes can be found on top of this branch here: git clone https://github.com/julien-thierry/linux.git -b objtoolxarm64-latest But it would be nice to have some feedback on this before I start submitting everyting. [1] https://lkml.org/lkml/2021/1/20/791 Thanks, Julien --> Julien Thierry (15): tools: Add some generic functions and headers tools: arm64: Make aarch64 instruction decoder available to tools tools: bug: Remove duplicate definition objtool: arm64: Add base definition for arm64 backend objtool: arm64: Decode add/sub instructions objtool: arm64: Decode jump and call related instructions objtool: arm64: Decode other system instructions objtool: arm64: Decode load/store instructions objtool: arm64: Decode LDR instructions objtool: arm64: Accept padding in code sections efi: libstub: Ignore relocations for .discard sections objtool: arm64: Implement functions to add switch tables alternatives objtool: arm64: Cache section with switch table information objtool: arm64: Handle supported relocations in alternatives objtool: arm64: Ignore replacement section for alternative callback Raphael Gault (2): gcc-plugins: objtool: Add plugin to detect switch table on arm64 objtool: arm64: Enable stack validation for arm64 arch/arm64/Kconfig | 2 + drivers/firmware/efi/libstub/Makefile | 2 +- scripts/Makefile.gcc-plugins | 2 + scripts/gcc-plugins/Kconfig | 4 + .../arm64_switch_table_detection_plugin.c | 85 + tools/arch/arm64/include/asm/aarch64-insn.h | 551 +++++++ tools/arch/arm64/lib/aarch64-insn.c | 1425 +++++++++++++++++ tools/include/asm-generic/bitops/__ffs.h | 11 + tools/include/linux/bug.h | 6 +- tools/include/linux/kernel.h | 21 + tools/include/linux/printk.h | 40 + tools/objtool/Makefile | 5 + tools/objtool/arch/arm64/Build | 8 + tools/objtool/arch/arm64/decode.c | 471 ++++++ .../arch/arm64/include/arch/cfi_regs.h | 14 + tools/objtool/arch/arm64/include/arch/elf.h | 6 + .../arch/arm64/include/arch/endianness.h | 9 + .../objtool/arch/arm64/include/arch/special.h | 23 + tools/objtool/arch/arm64/special.c | 134 ++ tools/objtool/arch/x86/decode.c | 5 + tools/objtool/check.c | 6 + tools/objtool/include/objtool/arch.h | 3 + tools/objtool/sync-check.sh | 5 + 23 files changed, 2832 insertions(+), 6 deletions(-) create mode 100644 scripts/gcc-plugins/arm64_switch_table_detection_plugin.c create mode 100644 tools/arch/arm64/include/asm/aarch64-insn.h create mode 100644 tools/arch/arm64/lib/aarch64-insn.c create mode 100644 tools/include/linux/printk.h create mode 100644 tools/objtool/arch/arm64/Build create mode 100644 tools/objtool/arch/arm64/decode.c create mode 100644 tools/objtool/arch/arm64/include/arch/cfi_regs.h create mode 100644 tools/objtool/arch/arm64/include/arch/elf.h create mode 100644 tools/objtool/arch/arm64/include/arch/endianness.h create mode 100644 tools/objtool/arch/arm64/include/arch/special.h create mode 100644 tools/objtool/arch/arm64/special.c -- 2.25.4
WARNING: multiple messages have this Message-ID (diff)
From: Julien Thierry <jthierry@redhat.com> To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: mark.rutland@arm.com, linux-efi@vger.kernel.org, michal.lkml@markovi.net, keescook@chromium.org, peterz@infradead.org, catalin.marinas@arm.com, masahiroy@kernel.org, broonie@kernel.org, linux-hardening@vger.kernel.org, jpoimboe@redhat.com, will@kernel.org, ardb@kernel.org, Julien Thierry <jthierry@redhat.com> Subject: [RFC PATCH 00/17] objtool: add base support for arm64 Date: Wed, 20 Jan 2021 18:37:43 +0100 [thread overview] Message-ID: <20210120173800.1660730-1-jthierry@redhat.com> (raw) Hi, This series enables objtool to start doing stack validation on arm64 kernel builds. It relies on the previous series I sent, refactoring the arm64 decoder [1]. First, the aarch64 instruction decoder needed to be made available to code under tools/. This is done in a similar manner to x86 instruction decoded. One limitation I encountered there is that most of aarch64 instruction decoder is __kprobe annotated. To bypass that it remove the kprobe include and had to add an empty __kprobe definition, but I'd welcome a proper solution to that. Then instruction semantics are progressively added so objtool can track the stack state through the execution flow. There are a few things that needed consideration: - Generation of constants within executable sections, these either caused objtool to fail decoding or to wrongly decode constants as jumps or other instructions affecting execution flow and causing confusion. To solve this, tracking locations referenced by instructions using literals was needed. - Jump tables from switch statements in aarch64 don't have enough information to link branches with the branch instruction leading to them. For this, we use a gcc plugin to add some information to establish those missing links in a format that is already supported by objtool With this, there are still some errors when building with objtool. A number of cleanups/annotations are needed on the arm64, as well as handling SYM_DATA objects in objtool. Those changes can be found on top of this branch here: git clone https://github.com/julien-thierry/linux.git -b objtoolxarm64-latest But it would be nice to have some feedback on this before I start submitting everyting. [1] https://lkml.org/lkml/2021/1/20/791 Thanks, Julien --> Julien Thierry (15): tools: Add some generic functions and headers tools: arm64: Make aarch64 instruction decoder available to tools tools: bug: Remove duplicate definition objtool: arm64: Add base definition for arm64 backend objtool: arm64: Decode add/sub instructions objtool: arm64: Decode jump and call related instructions objtool: arm64: Decode other system instructions objtool: arm64: Decode load/store instructions objtool: arm64: Decode LDR instructions objtool: arm64: Accept padding in code sections efi: libstub: Ignore relocations for .discard sections objtool: arm64: Implement functions to add switch tables alternatives objtool: arm64: Cache section with switch table information objtool: arm64: Handle supported relocations in alternatives objtool: arm64: Ignore replacement section for alternative callback Raphael Gault (2): gcc-plugins: objtool: Add plugin to detect switch table on arm64 objtool: arm64: Enable stack validation for arm64 arch/arm64/Kconfig | 2 + drivers/firmware/efi/libstub/Makefile | 2 +- scripts/Makefile.gcc-plugins | 2 + scripts/gcc-plugins/Kconfig | 4 + .../arm64_switch_table_detection_plugin.c | 85 + tools/arch/arm64/include/asm/aarch64-insn.h | 551 +++++++ tools/arch/arm64/lib/aarch64-insn.c | 1425 +++++++++++++++++ tools/include/asm-generic/bitops/__ffs.h | 11 + tools/include/linux/bug.h | 6 +- tools/include/linux/kernel.h | 21 + tools/include/linux/printk.h | 40 + tools/objtool/Makefile | 5 + tools/objtool/arch/arm64/Build | 8 + tools/objtool/arch/arm64/decode.c | 471 ++++++ .../arch/arm64/include/arch/cfi_regs.h | 14 + tools/objtool/arch/arm64/include/arch/elf.h | 6 + .../arch/arm64/include/arch/endianness.h | 9 + .../objtool/arch/arm64/include/arch/special.h | 23 + tools/objtool/arch/arm64/special.c | 134 ++ tools/objtool/arch/x86/decode.c | 5 + tools/objtool/check.c | 6 + tools/objtool/include/objtool/arch.h | 3 + tools/objtool/sync-check.sh | 5 + 23 files changed, 2832 insertions(+), 6 deletions(-) create mode 100644 scripts/gcc-plugins/arm64_switch_table_detection_plugin.c create mode 100644 tools/arch/arm64/include/asm/aarch64-insn.h create mode 100644 tools/arch/arm64/lib/aarch64-insn.c create mode 100644 tools/include/linux/printk.h create mode 100644 tools/objtool/arch/arm64/Build create mode 100644 tools/objtool/arch/arm64/decode.c create mode 100644 tools/objtool/arch/arm64/include/arch/cfi_regs.h create mode 100644 tools/objtool/arch/arm64/include/arch/elf.h create mode 100644 tools/objtool/arch/arm64/include/arch/endianness.h create mode 100644 tools/objtool/arch/arm64/include/arch/special.h create mode 100644 tools/objtool/arch/arm64/special.c -- 2.25.4 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next reply other threads:[~2021-01-20 18:59 UTC|newest] Thread overview: 106+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-01-20 17:37 Julien Thierry [this message] 2021-01-20 17:37 ` [RFC PATCH 00/17] objtool: add base support for arm64 Julien Thierry 2021-01-20 17:37 ` [RFC PATCH 01/17] tools: Add some generic functions and headers Julien Thierry 2021-01-20 17:37 ` Julien Thierry 2021-01-20 17:37 ` [RFC PATCH 02/17] tools: arm64: Make aarch64 instruction decoder available to tools Julien Thierry 2021-01-20 17:37 ` Julien Thierry 2021-01-20 17:37 ` [RFC PATCH 03/17] tools: bug: Remove duplicate definition Julien Thierry 2021-01-20 17:37 ` Julien Thierry 2021-01-20 17:37 ` [RFC PATCH 04/17] objtool: arm64: Add base definition for arm64 backend Julien Thierry 2021-01-20 17:37 ` Julien Thierry 2021-01-20 17:37 ` [RFC PATCH 05/17] objtool: arm64: Decode add/sub instructions Julien Thierry 2021-01-20 17:37 ` Julien Thierry 2021-01-20 17:37 ` [RFC PATCH 06/17] objtool: arm64: Decode jump and call related instructions Julien Thierry 2021-01-20 17:37 ` Julien Thierry 2021-01-20 17:37 ` [RFC PATCH 07/17] objtool: arm64: Decode other system instructions Julien Thierry 2021-01-20 17:37 ` Julien Thierry 2021-01-20 17:37 ` [RFC PATCH 08/17] objtool: arm64: Decode load/store instructions Julien Thierry 2021-01-20 17:37 ` Julien Thierry 2021-01-20 17:37 ` [RFC PATCH 09/17] objtool: arm64: Decode LDR instructions Julien Thierry 2021-01-20 17:37 ` Julien Thierry 2021-01-20 17:37 ` [RFC PATCH 10/17] objtool: arm64: Accept padding in code sections Julien Thierry 2021-01-20 17:37 ` Julien Thierry 2021-01-20 17:37 ` [RFC PATCH 11/17] efi: libstub: Ignore relocations for .discard sections Julien Thierry 2021-01-20 17:37 ` Julien Thierry 2021-01-20 17:37 ` [RFC PATCH 12/17] gcc-plugins: objtool: Add plugin to detect switch table on arm64 Julien Thierry 2021-01-20 17:37 ` Julien Thierry 2021-01-27 22:15 ` Nick Desaulniers 2021-01-27 22:15 ` Nick Desaulniers 2021-01-27 23:26 ` Josh Poimboeuf 2021-01-27 23:26 ` Josh Poimboeuf 2021-01-29 18:10 ` Nick Desaulniers 2021-01-29 18:10 ` Nick Desaulniers 2021-02-01 21:44 ` Josh Poimboeuf 2021-02-01 21:44 ` Josh Poimboeuf 2021-02-01 23:17 ` Nick Desaulniers 2021-02-01 23:17 ` Nick Desaulniers 2021-02-02 0:02 ` Josh Poimboeuf 2021-02-02 0:02 ` Josh Poimboeuf 2021-02-02 14:24 ` David Laight 2021-02-02 14:24 ` David Laight 2021-02-02 22:33 ` Nick Desaulniers 2021-02-02 22:33 ` Nick Desaulniers 2021-02-02 23:36 ` Josh Poimboeuf 2021-02-02 23:36 ` Josh Poimboeuf 2021-02-02 23:52 ` Nick Desaulniers 2021-02-02 23:52 ` Nick Desaulniers 2021-02-02 8:57 ` Julien Thierry 2021-02-02 8:57 ` Julien Thierry 2021-02-02 23:01 ` Nick Desaulniers 2021-02-02 23:01 ` Nick Desaulniers 2021-02-03 0:14 ` Josh Poimboeuf 2021-02-03 0:14 ` Josh Poimboeuf 2021-02-03 11:57 ` Peter Zijlstra 2021-02-03 11:57 ` Peter Zijlstra 2021-02-03 13:04 ` Mark Brown 2021-02-03 13:04 ` Mark Brown 2021-02-03 13:58 ` Mark Rutland 2021-02-03 13:58 ` Mark Rutland 2021-02-03 8:11 ` Julien Thierry 2021-02-03 8:11 ` Julien Thierry 2021-02-09 16:30 ` Daniel Kiss 2021-02-09 16:30 ` Daniel Kiss 2021-01-20 17:37 ` [RFC PATCH 13/17] objtool: arm64: Implement functions to add switch tables alternatives Julien Thierry 2021-01-20 17:37 ` Julien Thierry 2021-01-20 17:37 ` [RFC PATCH 14/17] objtool: arm64: Cache section with switch table information Julien Thierry 2021-01-20 17:37 ` Julien Thierry 2021-01-20 17:37 ` [RFC PATCH 15/17] objtool: arm64: Handle supported relocations in alternatives Julien Thierry 2021-01-20 17:37 ` Julien Thierry 2021-01-20 17:37 ` [RFC PATCH 16/17] objtool: arm64: Ignore replacement section for alternative callback Julien Thierry 2021-01-20 17:37 ` Julien Thierry 2021-01-20 17:38 ` [RFC PATCH 17/17] objtool: arm64: Enable stack validation for arm64 Julien Thierry 2021-01-20 17:38 ` Julien Thierry 2021-01-21 5:39 ` kernel test robot 2021-01-21 9:03 ` [RFC PATCH 00/17] objtool: add base support " Ard Biesheuvel 2021-01-21 9:03 ` Ard Biesheuvel 2021-01-21 10:26 ` Julien Thierry 2021-01-21 10:26 ` Julien Thierry 2021-01-21 11:08 ` Ard Biesheuvel 2021-01-21 11:08 ` Ard Biesheuvel 2021-01-21 11:23 ` Peter Zijlstra 2021-01-21 11:23 ` Peter Zijlstra 2021-01-21 11:48 ` Ard Biesheuvel 2021-01-21 11:48 ` Ard Biesheuvel 2021-01-21 18:54 ` Josh Poimboeuf 2021-01-21 18:54 ` Josh Poimboeuf 2021-01-22 17:43 ` Mark Brown 2021-01-22 17:43 ` Mark Brown 2021-01-22 17:54 ` Ard Biesheuvel 2021-01-22 17:54 ` Ard Biesheuvel 2021-01-28 22:10 ` Madhavan T. Venkataraman 2021-01-28 22:10 ` Madhavan T. Venkataraman 2021-01-29 15:47 ` Mark Brown 2021-01-22 21:15 ` Madhavan T. Venkataraman 2021-01-22 21:15 ` Madhavan T. Venkataraman 2021-01-22 21:43 ` Ard Biesheuvel 2021-01-22 21:43 ` Ard Biesheuvel 2021-01-22 21:44 ` Madhavan T. Venkataraman 2021-01-22 21:44 ` Madhavan T. Venkataraman 2021-01-25 21:19 ` Josh Poimboeuf 2021-01-25 21:19 ` Josh Poimboeuf 2021-01-22 21:16 ` Madhavan T. Venkataraman 2021-01-22 21:16 ` Madhavan T. Venkataraman 2021-01-21 13:23 ` Julien Thierry 2021-01-21 13:23 ` Julien Thierry 2021-01-21 14:23 ` Mark Brown 2021-01-21 14:23 ` Mark Brown
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