linux/tools/objtool/elf.h, branch v5.11

objtool: Fix seg fault with Clang non-section symbols

2020-12-16T13:35:46Z

The Clang assembler likes to strip section symbols, which means objtool can't reference some text code by its section. This confuses objtool greatly, causing it to seg fault. The fix is similar to what was done before, for ORC reloc generation: e81e07244325 ("objtool: Support Clang non-section symbols in ORC generation") Factor out that code into a common helper and use it for static call reloc generation as well. Reported-by: Arnd Bergmann Signed-off-by: Josh Poimboeuf Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Nick Desaulniers Reviewed-by: Miroslav Benes Link: https://github.com/ClangBuiltLinux/linux/issues/1207 Link: https://lkml.kernel.org/r/ba6b6c0f0dd5acbba66e403955a967d9fdd1726a.1607983452.git.jpoimboe@redhat.com

x86/static_call: Add inline static call implementation for x86-64

2020-09-01T07:58:05Z

Add the inline static call implementation for x86-64. The generated code is identical to the out-of-line case, except we move the trampoline into it's own section. Objtool uses the trampoline naming convention to detect all the call sites. It then annotates those call sites in the .static_call_sites section. During boot (and module init), the call sites are patched to call directly into the destination function. The temporary trampoline is then no longer used. [peterz: merged trampolines, put trampoline in section] Signed-off-by: Josh Poimboeuf Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Cc: Linus Torvalds Link: https://lore.kernel.org/r/20200818135804.864271425@infradead.org

Merge branch 'objtool/urgent' into objtool/core

2020-06-18T15:55:29Z

Conflicts: tools/objtool/elf.c tools/objtool/elf.h tools/objtool/orc_gen.c tools/objtool/check.c Signed-off-by: Peter Zijlstra (Intel)

objtool: Provide elf_write_{insn,reloc}()

2020-06-18T15:36:33Z

This provides infrastructure to rewrite instructions; this is immediately useful for helping out with KCOV-vs-noinstr, but will also come in handy for a bunch of variable sized jump-label patches that are still on ice. Signed-off-by: Peter Zijlstra (Intel)

objtool: Clean up elf_write() condition

2020-06-18T15:36:33Z

With there being multiple ways to change the ELF data, let's more concisely track modification. Signed-off-by: Peter Zijlstra (Intel)

objtool: Add support for relocations without addends

2020-06-02T20:37:04Z

Currently objtool only collects information about relocations with addends. In recordmcount, which we are about to merge into objtool, some supported architectures do not use rela relocations. Signed-off-by: Matt Helsley Reviewed-by: Julien Thierry Reviewed-by: Kamalesh Babulal Signed-off-by: Josh Poimboeuf

objtool: Rename rela to reloc

2020-06-01T14:40:58Z

Before supporting additional relocation types rename the relevant types and functions from "rela" to "reloc". This work be done with the following regex: sed -e 's/struct rela/struct reloc/g' \ -e 's/$[_\*]$rela$s\{0,1\}$/\1reloc\2/g' \ -e 's/tmprela$s\{0,1\}$/tmpreloc\1/g' \ -e 's/relasec/relocsec/g' \ -e 's/rela_list/reloc_list/g' \ -e 's/rela_hash/reloc_hash/g' \ -e 's/add_rela/add_reloc/g' \ -e 's/rela->/reloc->/g' \ -e '/rela[,\.]/{ s/$[^\.>]$rela$[\.,]$/\1reloc\2/g ; }' \ -e 's/rela =/reloc =/g' \ -e 's/relas =/relocs =/g' \ -e 's/relas\[/relocs[/g' \ -e 's/relaname =/relocname =/g' \ -e 's/= rela\;/= reloc\;/g' \ -e 's/= relas\;/= relocs\;/g' \ -e 's/= relaname\;/= relocname\;/g' \ -e 's/, rela)/, reloc)/g' \ -e 's/$[ @]$rela$[ "]$/\1reloc\2/g' \ -e 's/ rela$/ reloc/g' \ -e 's/, relaname/, relocname/g' \ -e 's/sec->rela/sec->reloc/g' \ -e 's/($!\{0,1\}$rela/(\1reloc/g' \ -i \ arch.h \ arch/x86/decode.c \ check.c \ check.h \ elf.c \ elf.h \ orc_gen.c \ special.c Notable exceptions which complicate the regex include gelf_* library calls and standard/expected section names which still use "rela" because they encode the type of relocation expected. Also, keep "rela" in the struct because it encodes a specific type of relocation we currently expect. It will eventually turn into a member of an anonymous union when a susequent patch adds implicit addend, or "rel", relocation support. Signed-off-by: Matt Helsley Signed-off-by: Josh Poimboeuf

Merge tag 'v5.7-rc6' into objtool/core, to pick up fixes and resolve semantic conflict

2020-05-18T10:09:37Z

Resolve structural conflict between: 59566b0b622e: ("x86/ftrace: Have ftrace trampolines turn read-only at the end of system boot up") which introduced a new reference to 'ftrace_epilogue', and: 0298739b7983: ("x86,ftrace: Fix ftrace_regs_caller() unwind") Which renamed it to 'ftrace_caller_end'. Rename the new usage site in the merge commit. Signed-off-by: Ingo Molnar

Merge tag 'x86-urgent-2020-05-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2020-05-10T18:59:53Z

Pull x86 fixes from Thomas Gleixner: "A set of fixes for x86: - Ensure that direct mapping alias is always flushed when changing page attributes. The optimization for small ranges failed to do so when the virtual address was in the vmalloc or module space. - Unbreak the trace event registration for syscalls without arguments caused by the refactoring of the SYSCALL_DEFINE0() macro. - Move the printk in the TSC deadline timer code to a place where it is guaranteed to only be called once during boot and cannot be rearmed by clearing warn_once after boot. If it's invoked post boot then lockdep rightfully complains about a potential deadlock as the calling context is different. - A series of fixes for objtool and the ORC unwinder addressing variety of small issues: - Stack offset tracking for indirect CFAs in objtool ignored subsequent pushs and pops - Repair the unwind hints in the register clearing entry ASM code - Make the unwinding in the low level exit to usermode code stop after switching to the trampoline stack. The unwind hint is no longer valid and the ORC unwinder emits a warning as it can't find the registers anymore. - Fix unwind hints in switch_to_asm() and rewind_stack_do_exit() which caused objtool to generate bogus ORC data. - Prevent unwinder warnings when dumping the stack of a non-current task as there is no way to be sure about the validity because the dumped stack can be a moving target. - Make the ORC unwinder behave the same way as the frame pointer unwinder when dumping an inactive tasks stack and do not skip the first frame. - Prevent ORC unwinding before ORC data has been initialized - Immediately terminate unwinding when a unknown ORC entry type is found. - Prevent premature stop of the unwinder caused by IRET frames. - Fix another infinite loop in objtool caused by a negative offset which was not catched. - Address a few build warnings in the ORC unwinder and add missing static/ro_after_init annotations" * tag 'x86-urgent-2020-05-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/unwind/orc: Move ORC sorting variables under !CONFIG_MODULES x86/apic: Move TSC deadline timer debug printk ftrace/x86: Fix trace event registration for syscalls without arguments x86/mm/cpa: Flush direct map alias during cpa objtool: Fix infinite loop in for_offset_range() x86/unwind/orc: Fix premature unwind stoppage due to IRET frames x86/unwind/orc: Fix error path for bad ORC entry type x86/unwind/orc: Prevent unwinding before ORC initialization x86/unwind/orc: Don't skip the first frame for inactive tasks x86/unwind: Prevent false warnings for non-current tasks x86/unwind/orc: Convert global variables to static x86/entry/64: Fix unwind hints in rewind_stack_do_exit() x86/entry/64: Fix unwind hints in __switch_to_asm() x86/entry/64: Fix unwind hints in kernel exit path x86/entry/64: Fix unwind hints in register clearing code objtool: Fix stack offset tracking for indirect CFAs

objtool: Move the IRET hack into the arch decoder

2020-04-30T18:14:33Z

Quoting Julien: "And the other suggestion is my other email was that you don't even need to add INSN_EXCEPTION_RETURN. You can keep IRET as INSN_CONTEXT_SWITCH by default and x86 decoder lookups the symbol conaining an iret. If it's a function symbol, it can just set the type to INSN_OTHER so that it caries on to the next instruction after having handled the stack_op." Suggested-by: Julien Thierry Signed-off-by: Miroslav Benes Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Miroslav Benes Acked-by: Josh Poimboeuf Link: https://lkml.kernel.org/r/20200428191659.913283807@infradead.org