kernel/linux.git/tools/objtool/arch/x86/include, branch v6.19.11

objtool: Add elf_create_section_pair()

2023-06-07T17:03:17+00:00

When creating an annotation section, allocate the reloc section data at the beginning. This simplifies the data model a bit and also saves memory due to the removal of malloc() in elf_rebuild_reloc_section(). With allyesconfig + CONFIG_DEBUG_INFO: - Before: peak heap memory consumption: 53.49G - After: peak heap memory consumption: 49.02G Link: https://lore.kernel.org/r/048e908f3ede9b66c15e44672b6dda992b1dae3e.1685464332.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf

x86/alternatives: Add alt_instr.flags

2023-01-05T11:46:47+00:00

Add a struct alt_instr.flags field which will contain different flags controlling alternatives patching behavior. The initial idea was to be able to specify it as a separate macro parameter but that would mean touching all possible invocations of the alternatives macros and thus a lot of churn. What is more, as PeterZ suggested, being able to say ALT_NOT(feature) is very readable and explains exactly what is meant. So make the feature field a u32 where the patching flags are the upper u16 part of the dword quantity while the lower u16 word is the feature. The highest feature number currently is 0x26a (i.e., word 19) so there is plenty of space. If that becomes insufficient, the field can be extended to u64 which will then make struct alt_instr of the nice size of 16 bytes (14 bytes currently). There should be no functional changes resulting from this. Suggested-by: Peter Zijlstra (Intel) Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Ingo Molnar Link: https://lore.kernel.org/r/Y6RCoJEtxxZWwotd@zn.tnic

objtool: Use macros to define arch specific reloc types

2022-11-18T08:00:16+00:00

Make relocation types architecture specific. Tested-by: Naveen N. Rao Reviewed-by: Naveen N. Rao Reviewed-by: Christophe Leroy Acked-by: Peter Zijlstra (Intel) Acked-by: Josh Poimboeuf Signed-off-by: Sathvika Vasireddy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20221114175754.1131267-14-sv@linux.ibm.com

objtool: Use target file endianness instead of a compiled constant

2022-11-18T08:00:15+00:00

Some architectures like powerpc support both endianness, it's therefore not possible to fix the endianness via arch/endianness.h because there is no easy way to get the target endianness at build time. Use the endianness recorded in the file objtool is working on. Tested-by: Naveen N. Rao Reviewed-by: Naveen N. Rao Acked-by: Josh Poimboeuf Acked-by: Peter Zijlstra (Intel) Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20221114175754.1131267-10-sv@linux.ibm.com

objtool: Decode jump_entry::key addend

2021-05-12T12:54:55+00:00

Teach objtool about the the low bits in the struct static_key pointer. That is, the low two bits of @key in: struct jump_entry { s32 code; s32 target; long key; } as found in the __jump_table section. Since @key has a relocation to the variable (to be resolved by the linker), the low two bits will be reflected in the relocation's addend. As such, find the reloc and store the addend, such that we can access these bits. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20210506194158.028024143@infradead.org

Merge tag 'objtool-core-2021-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2021-04-28T19:53:24+00:00

Pull objtool updates from Ingo Molnar: - Standardize the crypto asm code so that it looks like compiler- generated code to objtool - so that it can understand it. This enables unwinding from crypto asm code - and also fixes the last known remaining objtool warnings for LTO and more. - x86 decoder fixes: clean up and fix the decoder, and also extend it a bit - Misc fixes and cleanups * tag 'objtool-core-2021-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits) x86/crypto: Enable objtool in crypto code x86/crypto/sha512-ssse3: Standardize stack alignment prologue x86/crypto/sha512-avx2: Standardize stack alignment prologue x86/crypto/sha512-avx: Standardize stack alignment prologue x86/crypto/sha256-avx2: Standardize stack alignment prologue x86/crypto/sha1_avx2: Standardize stack alignment prologue x86/crypto/sha_ni: Standardize stack alignment prologue x86/crypto/crc32c-pcl-intel: Standardize jump table x86/crypto/camellia-aesni-avx2: Unconditionally allocate stack buffer x86/crypto/aesni-intel_avx: Standardize stack alignment prologue x86/crypto/aesni-intel_avx: Fix register usage comments x86/crypto/aesni-intel_avx: Remove unused macros objtool: Support asm jump tables objtool: Parse options from OBJTOOL_ARGS objtool: Collate parse_options() users objtool: Add --backup objtool,x86: More ModRM sugar objtool,x86: Rewrite ADD/SUB/AND objtool,x86: Support %riz encodings objtool,x86: Simplify register decode ...

x86/alternatives: Optimize optimize_nops()

2021-04-02T10:41:17+00:00

Currently, optimize_nops() scans to see if the alternative starts with NOPs. However, the emit pattern is: 141: \oldinstr 142: .skip (len-(142b-141b)), 0x90 That is, when 'oldinstr' is short, the tail is padded with NOPs. This case never gets optimized. Rewrite optimize_nops() to replace any trailing string of NOPs inside the alternative to larger NOPs. Also run it irrespective of patching, replacing NOPs in both the original and replaced code. A direct consequence is that 'padlen' becomes superfluous, so remove it. [ bp: - Adjust commit message - remove a stale comment about needing to pad - add a comment in optimize_nops() - exit early if the NOP verif. loop catches a mismatch - function should not not add NOPs in that case - fix the "optimized NOPs" offsets output ] Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Borislav Petkov Signed-off-by: Ingo Molnar Link: https://lkml.kernel.org/r/20210326151259.442992235@infradead.org

objtool,x86: Renumber CFI_reg

2021-03-06T11:44:22+00:00

Make them match the instruction encoding numbering. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Acked-by: Josh Poimboeuf Tested-by: Nick Desaulniers Link: https://lkml.kernel.org/r/20210211173627.033720313@infradead.org

objtool: Rework header include paths

2021-01-14T00:13:14+00:00

Currently objtool headers are being included either by their base name or included via ../ from a parent directory. In case of a base name usage: #include "warn.h" #include "arch_elf.h" it does not make it apparent from which directory the file comes from. To make it slightly better, and actually to avoid name clashes some arch specific files have "arch_" suffix. And files from an arch folder have to revert to including via ../ e.g: #include "../../elf.h" With additional architectures support and the code base growth there is a need for clearer headers naming scheme for multiple reasons: 1. to make it instantly obvious where these files come from (objtool itself / objtool arch|generic folders / some other external files), 2. to avoid name clashes of objtool arch specific headers, potential obtool arch generic headers and the system header files (there is /usr/include/elf.h already), 3. to avoid ../ includes and improve code readability. 4. to give a warm fuzzy feeling to developers who are mostly kernel developers and are accustomed to linux kernel headers arranging scheme. Doesn't this make it instantly obvious where are these files come from? #include #include And doesn't it look nicer to avoid ugly ../ includes? Which also guarantees this is elf.h from the objtool and not /usr/include/elf.h. #include This patch defines and implements new objtool headers arranging scheme. Which is: - all generic headers go to include/objtool (similar to include/linux) - all arch headers go to arch/$(SRCARCH)/include/arch (to get arch prefix). This is similar to linux arch specific "asm/*" headers but we are not abusing "asm" name and calling it what it is. This also helps to prevent name clashes (arch is not used in system headers or kernel exports). To bring objtool to this state the following things are done: 1. current top level tools/objtool/ headers are moved into include/objtool/ subdirectory, 2. arch specific headers, currently only arch/x86/include/ are moved into arch/x86/include/arch/ and were stripped of "arch_" suffix, 3. new -I$(srctree)/tools/objtool/include include path to make includes like possible, 4. rewriting file includes, 5. make git not to ignore include/objtool/ subdirectory. Signed-off-by: Vasily Gorbik Acked-by: Peter Zijlstra (Intel) Acked-by: Masami Hiramatsu Signed-off-by: Josh Poimboeuf

objtool: Fix x86 orc generation on big endian cross-compiles

2021-01-14T00:13:13+00:00

Correct objtool orc generation endianness problems to enable fully functional x86 cross-compiles on big endian hardware. Introduce bswap_if_needed() macro, which does a byte swap if target endianness doesn't match the host, i.e. cross-compilation for little endian on big endian and vice versa. The macro is used for conversion of multi-byte values which are read from / about to be written to a target native endianness ELF file. Signed-off-by: Vasily Gorbik Acked-by: Peter Zijlstra (Intel) Acked-by: Masami Hiramatsu Signed-off-by: Josh Poimboeuf