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2025-10-14objtool: Generalize elf_create_symbol()Josh Poimboeuf
In preparation for the objtool klp diff subcommand, broaden the elf_create_symbol() interface to give callers more control and reduce duplication of some subtle setup logic. While at it, make elf_create_symbol() and elf_create_section_symbol() global so sections can be created by the upcoming klp diff code. Acked-by: Petr Mladek <pmladek@suse.com> Tested-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14objtool: Simplify special symbol handling in elf_update_symbol()Josh Poimboeuf
!sym->sec isn't actually a thing: even STT_UNDEF and other special symbol types belong to NULL section 0. Simplify the initialization of 'shndx' accordingly. Acked-by: Petr Mladek <pmladek@suse.com> Tested-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14objtool: Refactor add_jump_destinations()Josh Poimboeuf
The add_jump_destinations() logic is a bit weird and convoluted after being incrementally tweaked over the years. Refactor it to hopefully be more logical and straightforward. Acked-by: Petr Mladek <pmladek@suse.com> Tested-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14objtool: Reindent check_options[]Josh Poimboeuf
Bring the cmdline check_options[] array back into vertical alignment for better readability. Acked-by: Petr Mladek <pmladek@suse.com> Tested-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14objtool: Resurrect --backup optionJosh Poimboeuf
The --backup option was removed with the following commit: aa8b3e64fd39 ("objtool: Create backup on error and print args") ... which tied the backup functionality to --verbose, and only for warnings/errors. It's a bit inelegant and out of scope to tie that to --verbose. Bring back the old --backup option, but with the new behavior: only on warnings/errors, and print the args to make it easier to recreate. Suggested-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Petr Mladek <pmladek@suse.com> Tested-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14objtool: Rename --Werror to --werrorJosh Poimboeuf
The objtool --Werror option name is stylistically inconsistent: halfway between GCC's single-dash capitalized -Werror and objtool's double-dash --lowercase convention, making it unnecessarily hard to remember. Make the 'W' lower case (--werror) for consistency with objtool's other options. Acked-by: Petr Mladek <pmladek@suse.com> Tested-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14objtool: Avoid emptying lists for duplicate sectionsJosh Poimboeuf
When a to-be-created section already exists, there's no point in emptying the various lists if their respective sections already exist. In fact it's better to leave them intact as they might get used later. Acked-by: Petr Mladek <pmladek@suse.com> Tested-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14objtool: Simplify reloc offset calculation in unwind_read_hints()Josh Poimboeuf
Simplify the relocation offset calculation in unwind_read_hints(), similar to other conversions which have already been done. Acked-by: Petr Mladek <pmladek@suse.com> Tested-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14objtool: Mark prefix functionsJosh Poimboeuf
In preparation for the objtool klp diff subcommand, introduce a flag to identify __pfx_*() and __cfi_*() functions in advance so they don't need to be manually identified every time a check is needed. Acked-by: Petr Mladek <pmladek@suse.com> Tested-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14objtool: Fix weak symbol hole detection for .cold functionsJosh Poimboeuf
When ignore_unreachable_insn() looks for weak function holes which jump to their .cold functions, it assumes the parent function comes before the corresponding .cold function in the symbol table. That's not necessarily the case with -ffunction-sections. Mark all the holes beforehand (including .cold functions) so the ordering of the discovery doesn't matter. Acked-by: Petr Mladek <pmladek@suse.com> Tested-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14objtool: Mark .cold subfunctionsJosh Poimboeuf
Introduce a flag to identify .cold subfunctions so they can be detected easier and faster. Acked-by: Petr Mladek <pmladek@suse.com> Tested-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14objtool: Add section/symbol type helpersJosh Poimboeuf
Add some helper macros to improve readability. Acked-by: Petr Mladek <pmladek@suse.com> Tested-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14objtool: Convert elf iterator macros to use 'struct elf'Josh Poimboeuf
'struct objtool_file' is specific to the check code and doesn't belong in the elf code which is supposed to be objtool_file-agnostic. Convert the elf iterator macros to use 'struct elf' instead. Acked-by: Petr Mladek <pmladek@suse.com> Tested-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14objtool: Remove .parainstructions referenceJosh Poimboeuf
The .parainstructions section no longer exists since the following commit: 60bc276b129e ("x86/paravirt: Switch mixed paravirt/alternative calls to alternatives"). Remove the reference to it. Acked-by: Petr Mladek <pmladek@suse.com> Tested-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14objtool: Clean up compiler flag usageJosh Poimboeuf
KBUILD_HOSTCFLAGS and KBUILD_HOSTLDFLAGS aren't defined when objtool is built standalone. Also, the EXTRA_WARNINGS flags are rather arbitrary. Make things simpler and more consistent by specifying compiler flags explicitly and tweaking the warnings. Also make a few code tweaks to make the new warnings happy. Acked-by: Petr Mladek <pmladek@suse.com> Tested-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14objtool: Const string cleanupJosh Poimboeuf
Use 'const char *' where applicable. Acked-by: Petr Mladek <pmladek@suse.com> Tested-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14objtool: Check for missing annotation entries in read_annotate()Josh Poimboeuf
Add a sanity check to make sure none of the relocations for the .discard.annotate_insn section have gone missing. Acked-by: Petr Mladek <pmladek@suse.com> Tested-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14objtool: Fix "unexpected end of section" warning for alternativesJosh Poimboeuf
Due to the short circuiting logic in next_insn_to_validate(), control flow may silently transition from .altinstr_replacement to .text without a corresponding nested call to validate_branch(). As a result the validate_branch() 'sec' variable doesn't get reinitialized, which can trigger a confusing "unexpected end of section" warning which blames .altinstr_replacement rather than the offending fallthrough function. Fix that by not caching the section. There's no point in doing that anyway. Acked-by: Petr Mladek <pmladek@suse.com> Tested-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14objtool: Fix __pa_symbol() relocation handlingJosh Poimboeuf
__pa_symbol() generates a relocation which refers to a physical address. Convert it to back its virtual form before calculating the addend. Acked-by: Petr Mladek <pmladek@suse.com> Tested-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14objtool: Fix x86 addend calculationJosh Poimboeuf
On x86, arch_dest_reloc_offset() hardcodes the addend adjustment to four, but the actual adjustment depends on the relocation type. Fix that. Acked-by: Petr Mladek <pmladek@suse.com> Tested-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14objtool: Fix weak symbol detectionJosh Poimboeuf
find_symbol_hole_containing() fails to find a symbol hole (aka stripped weak symbol) if its section has no symbols before the hole. This breaks weak symbol detection if -ffunction-sections is enabled. Fix that by allowing the interval tree to contain section symbols, which are always at offset zero for a given section. Fixes a bunch of (-ffunction-sections) warnings like: vmlinux.o: warning: objtool: .text.__x64_sys_io_setup+0x10: unreachable instruction Fixes: 4adb23686795 ("objtool: Ignore extra-symbol code") Acked-by: Petr Mladek <pmladek@suse.com> Tested-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14objtool: Fix interval tree insertion for zero-length symbolsJosh Poimboeuf
Zero-length symbols get inserted in the wrong spot. Fix that. Acked-by: Petr Mladek <pmladek@suse.com> Tested-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14objtool: Add empty symbols to the symbol tree againJosh Poimboeuf
The following commit 5da6aea375cd ("objtool: Fix find_{symbol,func}_containing()") fixed the issue where overlapping symbols weren't getting sorted properly in the symbol tree. Therefore the workaround to skip adding empty symbols from the following commit a2e38dffcd93 ("objtool: Don't add empty symbols to the rbtree") is no longer needed. Acked-by: Petr Mladek <pmladek@suse.com> Tested-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14objtool: Remove error handling boilerplateJosh Poimboeuf
Up to a certain point in objtool's execution, all errors are fatal and return -1. When propagating such errors, just return -1 directly instead of trying to propagate the original return code. This helps make the code more compact and the behavior more explicit. Acked-by: Petr Mladek <pmladek@suse.com> Tested-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14objtool: Propagate elf_truncate_section() error in elf_write()Josh Poimboeuf
Properly check and propagate the return value of elf_truncate_section() to avoid silent failures. Acked-by: Petr Mladek <pmladek@suse.com> Tested-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14objtool: Fix broken error handling in read_symbols()Josh Poimboeuf
The free(sym) call in the read_symbols() error path is fundamentally broken: 'sym' doesn't point to any allocated block. If triggered, things would go from bad to worse. Remove the free() and simplify the error paths. Freeing memory isn't necessary here anyway, these are fatal errors which lead to an immediate exit(). Acked-by: Petr Mladek <pmladek@suse.com> Tested-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14objtool: Make find_symbol_containing() less arbitraryJosh Poimboeuf
In the rare case of overlapping symbols, find_symbol_containing() just returns the first one it finds. Make it slightly less arbitrary by returning the smallest symbol with size > 0. Acked-by: Petr Mladek <pmladek@suse.com> Tested-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14interval_tree: Sync interval_tree_generic.h with toolsJosh Poimboeuf
The following commit made an improvement to interval_tree_generic.h, but didn't sync it to the tools copy: 19811285784f ("lib/interval_tree: skip the check before go to the right subtree") Sync it, and add it to objtool's sync-check.sh so they are more likely to stay in sync going forward. Acked-by: Petr Mladek <pmladek@suse.com> Tested-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14objtool: Fix standalone --hacks=jump_labelDylan Hatch
The objtool command line 'objtool --hacks=jump_label foo.o' on its own should be expected to rewrite jump labels to NOPs. This means the add_special_section_alts() code path needs to run when only this option is provided. This is mainly relevant in certain debugging situations, but could potentially also fix kernel builds in which objtool is run with --hacks=jump_label but without --orc, --stackval, --uaccess, or --hacks=noinstr. Fixes: de6fbcedf5ab ("objtool: Read special sections with alts only when specific options are selected") Signed-off-by: Dylan Hatch <dylanbhatch@google.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14objtool: Remove unneeded semicolonChen Ni
Remove unnecessary semicolons reported by Coccinelle/coccicheck and the semantic patch at scripts/coccinelle/misc/semicolon.cocci. Signed-off-by: Chen Ni <nichen@iscas.ac.cn> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14objtool/x86: Fix NOP decodePeter Zijlstra
For x86_64 the kernel consistently uses 2 instructions for all NOPs: 90 - NOP 0f 1f /0 - NOPL Notably: - REP NOP is PAUSE, not a NOP instruction. - 0f {0c...0f} is reserved space, except for 0f 0d /1, which is PREFETCHW, not a NOP. - 0f {19,1c...1f} is reserved space, except for 0f 1f /0, which is NOPL. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2025-10-14objtool/x86: Add UDB supportPeter Zijlstra
Per commit 85a2d4a890dc ("x86,ibt: Use UDB instead of 0xEA"), make sure objtool also recognises UDB as a #UD instruction. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
2025-10-14objtool/x86: Remove 0xea hackPeter Zijlstra
Was properly fixed in the decoder with commit 4b626015e1bf ("x86/insn: Stop decoding i64 instructions in x86-64 mode at opcode") Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
2025-10-11Merge tag 'x86_core_for_v6.18_rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull more x86 updates from Borislav Petkov: - Remove a bunch of asm implementing condition flags testing in KVM's emulator in favor of int3_emulate_jcc() which is written in C - Replace KVM fastops with C-based stubs which avoids problems with the fastop infra related to latter not adhering to the C ABI due to their special calling convention and, more importantly, bypassing compiler control-flow integrity checking because they're written in asm - Remove wrongly used static branches and other ugliness accumulated over time in hyperv's hypercall implementation with a proper static function call to the correct hypervisor call variant - Add some fixes and modifications to allow running FRED-enabled kernels in KVM even on non-FRED hardware - Add kCFI improvements like validating indirect calls and prepare for enabling kCFI with GCC. Add cmdline params documentation and other code cleanups - Use the single-byte 0xd6 insn as the official #UD single-byte undefined opcode instruction as agreed upon by both x86 vendors - Other smaller cleanups and touchups all over the place * tag 'x86_core_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits) x86,retpoline: Optimize patch_retpoline() x86,ibt: Use UDB instead of 0xEA x86/cfi: Remove __noinitretpoline and __noretpoline x86/cfi: Add "debug" option to "cfi=" bootparam x86/cfi: Standardize on common "CFI:" prefix for CFI reports x86/cfi: Document the "cfi=" bootparam options x86/traps: Clarify KCFI instruction layout compiler_types.h: Move __nocfi out of compiler-specific header objtool: Validate kCFI calls x86/fred: KVM: VMX: Always use FRED for IRQs when CONFIG_X86_FRED=y x86/fred: Play nice with invoking asm_fred_entry_from_kvm() on non-FRED hardware x86/fred: Install system vector handlers even if FRED isn't fully enabled x86/hyperv: Use direct call to hypercall-page x86/hyperv: Clean up hv_do_hypercall() KVM: x86: Remove fastops KVM: x86: Convert em_salc() to C KVM: x86: Introduce EM_ASM_3WCL KVM: x86: Introduce EM_ASM_1SRC2 KVM: x86: Introduce EM_ASM_2CL KVM: x86: Introduce EM_ASM_2W ...
2025-10-01Merge tag 'kbuild-6.18-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux Pull Kbuild updates from Nathan Chancellor: - Extend modules.builtin.modinfo to include module aliases from MODULE_DEVICE_TABLE for builtin modules so that userspace tools (such as kmod) can verify that a particular module alias will be handled by a builtin module - Bump the minimum version of LLVM for building the kernel to 15.0.0 - Upgrade several userspace API checks in headers_check.pl to errors - Unify and consolidate CONFIG_WERROR / W=e handling - Turn assembler and linker warnings into errors with CONFIG_WERROR / W=e - Respect CONFIG_WERROR / W=e when building userspace programs (userprogs) - Enable -Werror unconditionally when building host programs (hostprogs) - Support copy_file_range() and data segment alignment in gen_init_cpio to improve performance on filesystems that support reflinks such as btrfs and XFS - Miscellaneous small changes to scripts and configuration files * tag 'kbuild-6.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux: (47 commits) modpost: Initialize builtin_modname to stop SIGSEGVs Documentation: kbuild: note CONFIG_DEBUG_EFI in reproducible builds kbuild: vmlinux.unstripped should always depend on .vmlinux.export.o modpost: Create modalias for builtin modules modpost: Add modname to mod_device_table alias scsi: Always define blogic_pci_tbl structure kbuild: extract modules.builtin.modinfo from vmlinux.unstripped kbuild: keep .modinfo section in vmlinux.unstripped kbuild: always create intermediate vmlinux.unstripped s390: vmlinux.lds.S: Reorder sections KMSAN: Remove tautological checks objtool: Drop noinstr hack for KCSAN_WEAK_MEMORY lib/Kconfig.debug: Drop CLANG_VERSION check from DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT riscv: Remove ld.lld version checks from many TOOLCHAIN_HAS configs riscv: Unconditionally use linker relaxation riscv: Remove version check for LTO_CLANG selects powerpc: Drop unnecessary initializations in __copy_inst_from_kernel_nofault() mips: Unconditionally select ARCH_HAS_CURRENT_STACK_POINTER arm64: Remove tautological LLVM Kconfig conditions ARM: Clean up definition of ARM_HAS_GROUP_RELOCS ...
2025-09-30Merge tag 'x86_apic_for_v6.18_rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 SEV and apic updates from Borislav Petkov: - Add functionality to provide runtime firmware updates for the non-x86 parts of an AMD platform like the security processor (ASP) firmware, modules etc, for example. The intent being that these updates are interim, live fixups before a proper BIOS update can be attempted - Add guest support for AMD's Secure AVIC feature which gives encrypted guests the needed protection against a malicious hypervisor generating unexpected interrupts and injecting them into such guest, thus interfering with its operation in an unexpected and negative manner. The advantage of this scheme is that the guest determines which interrupts and when to accept them vs leaving that to the benevolence (or not) of the hypervisor - Strictly separate the startup code from the rest of the kernel where former is executed from the initial 1:1 mapping of memory. The problem was that the toolchain-generated version of the code was being executed from a different mapping of memory than what was "assumed" during code generation, needing an ever-growing pile of fixups for absolute memory references which are invalid in the early, 1:1 memory mapping during boot. The major advantage of this is that there's no need to check the 1:1 mapping portion of the code for absolute relocations anymore and get rid of the RIP_REL_REF() macro sprinkling all over the place. For more info, see Ard's very detailed writeup on this [1] - The usual cleanups and fixes Link: https://lore.kernel.org/r/CAMj1kXEzKEuePEiHB%2BHxvfQbFz0sTiHdn4B%2B%2BzVBJ2mhkPkQ4Q@mail.gmail.com [1] * tag 'x86_apic_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (49 commits) x86/boot: Drop erroneous __init annotation from early_set_pages_state() crypto: ccp - Add AMD Seamless Firmware Servicing (SFS) driver crypto: ccp - Add new HV-Fixed page allocation/free API x86/sev: Add new dump_rmp parameter to snp_leak_pages() API x86/startup/sev: Document the CPUID flow in the boot #VC handler objtool: Ignore __pi___cfi_ prefixed symbols x86/sev: Zap snp_abort() x86/apic/savic: Do not use snp_abort() x86/boot: Get rid of the .head.text section x86/boot: Move startup code out of __head section efistub/x86: Remap inittext read-execute when needed x86/boot: Create a confined code area for startup code x86/kbuild: Incorporate boot/startup/ via Kbuild makefile x86/boot: Revert "Reject absolute references in .head.text" x86/boot: Check startup code for absence of absolute relocations objtool: Add action to check for absence of absolute relocations x86/sev: Export startup routines for later use x86/sev: Move __sev_[get|put]_ghcb() into separate noinstr object x86/sev: Provide PIC aliases for SEV related data objects x86/boot: Provide PIC aliases for 5-level paging related constants ...
2025-09-19Merge 6.17-rc6 into kbuild-nextNathan Chancellor
Commit bd7c2312128e ("pinctrl: meson: Fix typo in device table macro") is needed in kbuild-next to avoid a build error with a future change. While at it, address the conflict between commit 41f9049cff32 ("riscv: Only allow LTO with CMODEL_MEDANY") and commit 6578a1ff6aa4 ("riscv: Remove version check for LTO_CLANG selects"), as reported by Stephen Rothwell [1]. Link: https://lore.kernel.org/20250908134913.68778b7b@canb.auug.org.au/ [1] Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2025-09-18objtool/LoongArch: Mark special atomic instruction as INSN_BUG typeTiezhu Yang
When compiling with LLVM and CONFIG_RUST is set, there exists the following objtool warning: rust/compiler_builtins.o: warning: objtool: __rust__unordsf2(): unexpected end of section .text.unlikely. objdump shows that the end of section .text.unlikely is an atomic instruction: amswap.w $zero, $ra, $zero According to the LoongArch Reference Manual, if the amswap.w atomic memory access instruction has the same register number as rd and rj, the execution will trigger an Instruction Non-defined Exception, so mark the above instruction as INSN_BUG type to fix the warning. Cc: stable@vger.kernel.org Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2025-09-18objtool/LoongArch: Mark types based on break immediate codeTiezhu Yang
If the break immediate code is 0, it should mark the type as INSN_TRAP. If the break immediate code is 1, it should mark the type as INSN_BUG. While at it, format the code style and add the code comment for nop. Cc: stable@vger.kernel.org Suggested-by: WANG Rui <wangrui@loongson.cn> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2025-09-09objtool: Ignore __pi___cfi_ prefixed symbolsNathan Chancellor
When building with CONFIG_CFI_CLANG=y after the recent series to separate the x86 startup code, there are objtool warnings along the lines of: vmlinux.o: warning: objtool: __pi___cfi_startup_64_load_idt() falls through to next function __pi_startup_64_load_idt() vmlinux.o: warning: objtool: __pi___cfi_startup_64_setup_gdt_idt() falls through to next function __pi_startup_64_setup_gdt_idt() vmlinux.o: warning: objtool: __pi___cfi___startup_64() falls through to next function __pi___startup_64() As the comment in validate_branch() states, this is expected, so ignore these symbols in the same way that __cfi_ and __pfx_ symbols are already ignored for the rest of the kernel. Fixes: 7b38dec3c5af ("x86/boot: Create a confined code area for startup code") Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Acked-by: Ard Biesheuvel <ardb@kernel.org>
2025-09-04x86/sev: Zap snp_abort()Borislav Petkov (AMD)
It is a silly oneliner anyway. Replace it with its equivalent. No functional changes. Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
2025-09-03x86/boot: Create a confined code area for startup codeArd Biesheuvel
In order to be able to have tight control over which code may execute from the early 1:1 mapping of memory, but still link vmlinux as a single executable, prefix all symbol references in startup code with __pi_, and invoke it from outside using the __pi_ prefix. Use objtool to check that no absolute symbol references are present in the startup code, as these cannot be used from code running from the 1:1 mapping. Note that this also requires disabling the latent-entropy GCC plugin, as the global symbol references that it injects would require explicit exports, and given that the startup code rarely executes more than once, it is not a useful source of entropy anyway. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/20250828102202.1849035-43-ardb+git@google.com
2025-09-03objtool: Add action to check for absence of absolute relocationsArd Biesheuvel
The x86 startup code must not use absolute references to code or data, as it executes before the kernel virtual mapping is up. Add an action to objtool to check all allocatable sections (with the exception of __patchable_function_entries, which uses absolute references for nebulous reasons) and raise an error if any absolute references are found. Note that debug sections typically contain lots of absolute references too, but those are not allocatable so they will be ignored. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/20250828102202.1849035-39-ardb+git@google.com
2025-08-28objtool: Drop noinstr hack for KCSAN_WEAK_MEMORYNathan Chancellor
Now that the minimum supported version of LLVM for building the kernel has been bumped to 15.0.0, __no_kcsan will always ensure that the thread sanitizer functions are not generated, so remove the check for tsan functions in is_profiling_func() and the always true depends and unnecessary select lines in KCSAN_WEAK_MEMORY. Acked-by: Marco Elver <elver@google.com> Acked-by: Peter Zijlstra (Intel) <peterz@infraded.org> Reviewed-by: Kees Cook <kees@kernel.org> Link: https://lore.kernel.org/r/20250821-bump-min-llvm-ver-15-v2-11-635f3294e5f0@kernel.org Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2025-08-20objtool/LoongArch: Get table size correctly if LTO is enabledTiezhu Yang
When compiling with LLVM and CONFIG_LTO_CLANG is set, there exist many objtool warnings "sibling call from callable instruction with modified stack frame". For this special case, the related object file shows that there is no generated relocation section '.rela.discard.tablejump_annotate' for the table jump instruction jirl, thus objtool can not know that what is the actual destination address. It needs to do something on the LLVM side to make sure that there is the relocation section '.rela.discard.tablejump_annotate' if LTO is enabled, but in order to maintain compatibility for the current LLVM compiler, this can be done in the kernel Makefile for now. Ensure it is aware of linker with LTO, '--loongarch-annotate-tablejump' needs to be passed via '-mllvm' to ld.lld. Before doing the above changes, it should handle the special case of the relocation section '.rela.discard.tablejump_annotate' to get the correct table size first, otherwise there are many objtool warnings and errors if LTO is enabled. There are many different rodata for each function if LTO is enabled, it is necessary to enhance get_rodata_table_size_by_table_annotate(). Fixes: b95f852d3af2 ("objtool/LoongArch: Add support for switch table") Closes: https://lore.kernel.org/loongarch/20250731175655.GA1455142@ax162/ Reported-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2025-08-18objtool: Validate kCFI callsPeter Zijlstra
Validate that all indirect calls adhere to kCFI rules. Notably doing nocfi indirect call to a cfi function is broken. Apparently some Rust 'core' code violates this and explodes when ran with FineIBT. All the ANNOTATE_NOCFI_SYM sites are prime targets for attackers. - runtime EFI is especially henous because it also needs to disable IBT. Basically calling unknown code without CFI protection at runtime is a massice security issue. - Kexec image handover; if you can exploit this, you get to keep it :-) Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Acked-by: Sean Christopherson <seanjc@google.com> Link: https://lkml.kernel.org/r/20250714103441.496787279@infradead.org
2025-07-30Merge tag 'trace-rv-6.17' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull runtime verification updates from Steven Rostedt: - Added Linear temporal logic monitors for RT application Real-time applications may have design flaws causing them to have unexpected latency. For example, the applications may raise page faults, or may be blocked trying to take a mutex without priority inheritance. However, while attempting to implement DA monitors for these real-time rules, deterministic automaton is found to be inappropriate as the specification language. The automaton is complicated, hard to understand, and error-prone. For these cases, linear temporal logic is found to be more suitable. The LTL is more concise and intuitive. - Make printk_deferred() public The new monitors needed access to printk_deferred(). Make them visible for the entire kernel. - Add a vpanic() to allow for va_list to be passed to panic. - Add rtapp container monitor. A collection of monitors that check for common problems with real-time applications that cause unexpected latency. - Add page fault tracepoints to risc-v These tracepoints are necessary to for the RV monitor to run on risc-v. - Fix the behaviour of the rv tool with -s and idle tasks. - Allow the rv tool to gracefully terminate with SIGTERM - Adjusts dot2c not to create lines over 100 columns - Properly order nested monitors in the RV Kconfig file - Return the registration error in all DA monitor instead of 0 - Update and add new sched collection monitors Replace tss and sncid monitors with more complete sts: Not only prove that switches occur in scheduling context and scheduling needs interrupt disabled but also that each call to the scheduler disables interrupts to (optionally) switch. New monitor: nrp Preemption requires need resched which is cleared by any switch (includes a non optimal workaround for /nested/ preemptions) New monitor: sssw suspension requires setting the task to sleepable and, after the switch occurs, the task requires a wakeup to come back to runnable New monitor: opid waking and need-resched operations occur with interrupts and preemption disabled or in IRQ without explicitly disabling preemption" * tag 'trace-rv-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (48 commits) rv: Add opid per-cpu monitor rv: Add nrp and sssw per-task monitors rv: Replace tss and sncid monitors with more complete sts sched: Adapt sched tracepoints for RV task model rv: Retry when da monitor detects race conditions rv: Adjust monitor dependencies rv: Use strings in da monitors tracepoints rv: Remove trailing whitespace from tracepoint string rv: Add da_handle_start_run_event_ to per-task monitors rv: Fix wrong type cast in reactors_show() and monitor_reactor_show() rv: Fix wrong type cast in monitors_show() rv: Remove struct rv_monitor::reacting rv: Remove rv_reactor's reference counter rv: Merge struct rv_reactor_def into struct rv_reactor rv: Merge struct rv_monitor_def into struct rv_monitor rv: Remove unused field in struct rv_monitor_def rv: Return init error when registering monitors verification/rvgen: Organise Kconfig entries for nested monitors tools/dot2c: Fix generated files going over 100 column limit tools/rv: Stop gracefully also on SIGTERM ...
2025-07-28Merge tag 'hardening-v6.17-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull hardening updates from Kees Cook: - Introduce and start using TRAILING_OVERLAP() helper for fixing embedded flex array instances (Gustavo A. R. Silva) - mux: Convert mux_control_ops to a flex array member in mux_chip (Thorsten Blum) - string: Group str_has_prefix() and strstarts() (Andy Shevchenko) - Remove KCOV instrumentation from __init and __head (Ritesh Harjani, Kees Cook) - Refactor and rename stackleak feature to support Clang - Add KUnit test for seq_buf API - Fix KUnit fortify test under LTO * tag 'hardening-v6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (22 commits) sched/task_stack: Add missing const qualifier to end_of_stack() kstack_erase: Support Clang stack depth tracking kstack_erase: Add -mgeneral-regs-only to silence Clang warnings init.h: Disable sanitizer coverage for __init and __head kstack_erase: Disable kstack_erase for all of arm compressed boot code x86: Handle KCOV __init vs inline mismatches arm64: Handle KCOV __init vs inline mismatches s390: Handle KCOV __init vs inline mismatches arm: Handle KCOV __init vs inline mismatches mips: Handle KCOV __init vs inline mismatch powerpc/mm/book3s64: Move kfence and debug_pagealloc related calls to __init section configs/hardening: Enable CONFIG_INIT_ON_FREE_DEFAULT_ON configs/hardening: Enable CONFIG_KSTACK_ERASE stackleak: Split KSTACK_ERASE_CFLAGS from GCC_PLUGINS_CFLAGS stackleak: Rename stackleak_track_stack to __sanitizer_cov_stack_depth stackleak: Rename STACKLEAK to KSTACK_ERASE seq_buf: Introduce KUnit tests string: Group str_has_prefix() and strstarts() kunit/fortify: Add back "volatile" for sizeof() constants acpi: nfit: intel: avoid multiple -Wflex-array-member-not-at-end warnings ...
2025-07-21stackleak: Rename stackleak_track_stack to __sanitizer_cov_stack_depthKees Cook
The Clang stack depth tracking implementation has a fixed name for the stack depth tracking callback, "__sanitizer_cov_stack_depth", so rename the GCC plugin function to match since the plugin has no external dependencies on naming. Link: https://lore.kernel.org/r/20250717232519.2984886-2-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2025-07-21stackleak: Rename STACKLEAK to KSTACK_ERASEKees Cook
In preparation for adding Clang sanitizer coverage stack depth tracking that can support stack depth callbacks: - Add the new top-level CONFIG_KSTACK_ERASE option which will be implemented either with the stackleak GCC plugin, or with the Clang stack depth callback support. - Rename CONFIG_GCC_PLUGIN_STACKLEAK as needed to CONFIG_KSTACK_ERASE, but keep it for anything specific to the GCC plugin itself. - Rename all exposed "STACKLEAK" names and files to "KSTACK_ERASE" (named for what it does rather than what it protects against), but leave as many of the internals alone as possible to avoid even more churn. While here, also split "prev_lowest_stack" into CONFIG_KSTACK_ERASE_METRICS, since that's the only place it is referenced from. Suggested-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20250717232519.2984886-1-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>