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2020-04-22objtool: Remove redundant .rodata section name comparisonMuchun Song
If the prefix of section name is not '.rodata', the following function call can never return 0. strcmp(sec->name, C_JUMP_TABLE_SECTION) So the name comparison is pointless, just remove it. Signed-off-by: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-04-22objtool: Documentation: document UACCESS warningsNick Desaulniers
Compiling with Clang and CONFIG_KASAN=y was exposing a few warnings: call to memset() with UACCESS enabled Document how to fix these for future travelers. Link: https://github.com/ClangBuiltLinux/linux/issues/876 Suggested-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Suggested-by: Matt Helsley <mhelsley@vmware.com> Suggested-by: Peter Zijlstra <peterz@infradead.org> Suggested-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-04-22objtool: Split out arch-specific CFI definitionsJulien Thierry
Some CFI definitions used by generic objtool code have no reason to vary from one architecture to another. Keep those definitions in generic code and move the arch-specific ones to a new arch-specific header. Signed-off-by: Julien Thierry <jthierry@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-04-22objtool: Add abstraction for destination offsetsRaphael Gault
The jump and call destination relocation offsets are x86-specific. Abstract them by calling arch-specific implementations. [ jthierry: Remove superfluous comment; replace other addend offsets with arch_dest_rela_offset() ] Signed-off-by: Raphael Gault <raphael.gault@arm.com> Signed-off-by: Julien Thierry <jthierry@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-04-22objtool: Use arch specific values in restore_reg()Julien Thierry
The initial register state is set up by arch specific code. Use the value the arch code has set when restoring registers from the stack. Suggested-by: Raphael Gault <raphael.gault@arm.com> Signed-off-by: Julien Thierry <jthierry@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-04-22objtool: Ignore empty alternativesJulien Thierry
The .alternatives section can contain entries with no original instructions. Objtool will currently crash when handling such an entry. Just skip that entry, but still give a warning to discourage useless entries. Signed-off-by: Julien Thierry <jthierry@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-04-22objtool: Clean instruction state before each function validationJulien Thierry
When a function fails its validation, it might leave a stale state that will be used for the validation of other functions. That would cause false warnings on potentially valid functions. Reset the instruction state before the validation of each individual function. Signed-off-by: Julien Thierry <jthierry@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-04-22objtool: Remove redundant checks on operand typeJulien Thierry
POP operations are already in the code path where the destination operand is OP_DEST_REG. There is no need to check the operand type again. Signed-off-by: Julien Thierry <jthierry@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-04-22objtool: Always do header sync checkJulien Thierry
Currently, the check of tools files against kernel equivalent is only done after every object file has been built. This means one might fix build issues against outdated headers without seeing a warning about this. Check headers before any object is built. Also, make it part of a FORCE'd recipe so every attempt to build objtool will report the outdated headers (if any). Signed-off-by: Julien Thierry <jthierry@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-04-22objtool: Fix off-by-one in symbol_by_offset()Julien Thierry
Sometimes, WARN_FUNC() and other users of symbol_by_offset() will associate the first instruction of a symbol with the symbol preceding it. This is because symbol->offset + symbol->len is already outside of the symbol's range. Fixes: 2a362ecc3ec9 ("objtool: Optimize find_symbol_*() and read_symbols()") Signed-off-by: Julien Thierry <jthierry@redhat.com> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-04-22objtool: Fix 32bit cross buildsPeter Zijlstra
Apparently there's people doing 64bit builds on 32bit machines. Fixes: 74b873e49d92 ("objtool: Optimize find_rela_by_dest_range()") Reported-by: youling257@gmail.com Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-04-14objtool: Make BP scratch register warning more robustJosh Poimboeuf
If func is NULL, a seg fault can result. This is a theoretical issue which was found by Coverity, ID: 1492002 ("Dereference after null check"). Fixes: c705cecc8431 ("objtool: Track original function across branches") Reported-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/afc628693a37acd287e843bcc5c0430263d93c74.1585761021.git.jpoimboe@redhat.com
2020-04-14objtool: Fix switch table detection in .text.unlikelyJosh Poimboeuf
If a switch jump table's indirect branch is in a ".cold" subfunction in .text.unlikely, objtool doesn't detect it, and instead prints a false warning: drivers/media/v4l2-core/v4l2-ioctl.o: warning: objtool: v4l_print_format.cold()+0xd6: sibling call from callable instruction with modified stack frame drivers/hwmon/max6650.o: warning: objtool: max6650_probe.cold()+0xa5: sibling call from callable instruction with modified stack frame drivers/media/dvb-frontends/drxk_hard.o: warning: objtool: init_drxk.cold()+0x16f: sibling call from callable instruction with modified stack frame Fix it by comparing the function, instead of the section and offset. Fixes: 13810435b9a7 ("objtool: Support GCC 8's cold subfunctions") Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/157c35d42ca9b6354bbb1604fe9ad7d1153ccb21.1585761021.git.jpoimboe@redhat.com
2020-04-14objtool: Support Clang non-section symbols in ORC generationJosh Poimboeuf
When compiling the kernel with AS=clang, objtool produces a lot of warnings: warning: objtool: missing symbol for section .text warning: objtool: missing symbol for section .init.text warning: objtool: missing symbol for section .ref.text It then fails to generate the ORC table. The problem is that objtool assumes text section symbols always exist. But the Clang assembler is aggressive about removing them. When generating relocations for the ORC table, objtool always tries to reference instructions by their section symbol offset. If the section symbol doesn't exist, it bails. Do a fallback: when a section symbol isn't available, reference a function symbol instead. Reported-by: Dmitry Golovin <dima@golovin.in> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Tested-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://github.com/ClangBuiltLinux/linux/issues/669 Link: https://lkml.kernel.org/r/9a9cae7fcf628843aabe5a086b1a3c5bf50f42e8.1585761021.git.jpoimboe@redhat.com
2020-04-14objtool: Support Clang non-section symbols in ORC dumpJosh Poimboeuf
Historically, the relocation symbols for ORC entries have only been section symbols: .text+0: sp:sp+8 bp:(und) type:call end:0 However, the Clang assembler is aggressive about stripping section symbols. In that case we will need to use function symbols: freezing_slow_path+0: sp:sp+8 bp:(und) type:call end:0 In preparation for the generation of such entries in "objtool orc generate", add support for reading them in "objtool orc dump". Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/b811b5eb1a42602c3b523576dc5efab9ad1c174d.1585761021.git.jpoimboe@redhat.com
2020-04-14objtool: Fix CONFIG_UBSAN_TRAP unreachable warningsJosh Poimboeuf
CONFIG_UBSAN_TRAP causes GCC to emit a UD2 whenever it encounters an unreachable code path. This includes __builtin_unreachable(). Because the BUG() macro uses __builtin_unreachable() after it emits its own UD2, this results in a double UD2. In this case objtool rightfully detects that the second UD2 is unreachable: init/main.o: warning: objtool: repair_env_string()+0x1c8: unreachable instruction We weren't able to figure out a way to get rid of the double UD2s, so just silence the warning. Reported-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/6653ad73c6b59c049211bd7c11ed3809c20ee9f5.1585761021.git.jpoimboe@redhat.com
2020-04-13objtool, kcsan: Add explicit check functions to uaccess whitelistMarco Elver
Add explicitly invoked KCSAN check functions to objtool's uaccess whitelist. This is needed in order to permit calling into kcsan_check_scoped_accesses() from the fast-path, which in turn calls __kcsan_check_access(). __kcsan_check_access() is the generic variant of the already whitelisted specializations __tsan_{read,write}N. Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-04-13Merge tag 'v5.7-rc1' into locking/kcsan, to resolve conflicts and refreshIngo Molnar
Resolve these conflicts: arch/x86/Kconfig arch/x86/kernel/Makefile Do a minor "evil merge" to move the KCSAN entry up a bit by a few lines in the Kconfig to reduce the probability of future conflicts. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-04-09kbuild: support LLVM=1 to switch the default tools to Clang/LLVMMasahiro Yamada
As Documentation/kbuild/llvm.rst implies, building the kernel with a full set of LLVM tools gets very verbose and unwieldy. Provide a single switch LLVM=1 to use Clang and LLVM tools instead of GCC and Binutils. You can pass it from the command line or as an environment variable. Please note LLVM=1 does not turn on the integrated assembler. You need to pass LLVM_IAS=1 to use it. When the upstream kernel is ready for the integrated assembler, I think we can make it default. We discussed what we need, and we agreed to go with a simple boolean flag that switches both target and host tools: https://lkml.org/lkml/2020/3/28/494 https://lkml.org/lkml/2020/4/3/43 Some items discussed, but not adopted: - LLVM_DIR When multiple versions of LLVM are installed, I just thought supporting LLVM_DIR=/path/to/my/llvm/bin/ might be useful. CC = $(LLVM_DIR)clang LD = $(LLVM_DIR)ld.lld ... However, we can handle this by modifying PATH. So, we decided to not do this. - LLVM_SUFFIX Some distributions (e.g. Debian) package specific versions of LLVM with naming conventions that use the version as a suffix. CC = clang$(LLVM_SUFFIX) LD = ld.lld(LLVM_SUFFIX) ... will allow a user to pass LLVM_SUFFIX=-11 to use clang-11 etc., but the suffixed versions in /usr/bin/ are symlinks to binaries in /usr/lib/llvm-#/bin/, so this can also be handled by PATH. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Tested-by: Nathan Chancellor <natechancellor@gmail.com> # build Tested-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2020-04-03Merge tag 'spdx-5.7-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx Pull SPDX updates from Greg KH: "Here are three SPDX patches for 5.7-rc1. One fixes up the SPDX tag for a single driver, while the other two go through the tree and add SPDX tags for all of the .gitignore files as needed. Nothing too complex, but you will get a merge conflict with your current tree, that should be trivial to handle (one file modified by two things, one file deleted.) All three of these have been in linux-next for a while, with no reported issues other than the merge conflict" * tag 'spdx-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx: ASoC: MT6660: make spdxcheck.py happy .gitignore: add SPDX License Identifier .gitignore: remove too obvious comments
2020-03-30Merge branch 'locking-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking updates from Ingo Molnar: "The main changes in this cycle were: - Continued user-access cleanups in the futex code. - percpu-rwsem rewrite that uses its own waitqueue and atomic_t instead of an embedded rwsem. This addresses a couple of weaknesses, but the primary motivation was complications on the -rt kernel. - Introduce raw lock nesting detection on lockdep (CONFIG_PROVE_RAW_LOCK_NESTING=y), document the raw_lock vs. normal lock differences. This too originates from -rt. - Reuse lockdep zapped chain_hlocks entries, to conserve RAM footprint on distro-ish kernels running into the "BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low!" depletion of the lockdep chain-entries pool. - Misc cleanups, smaller fixes and enhancements - see the changelog for details" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (55 commits) fs/buffer: Make BH_Uptodate_Lock bit_spin_lock a regular spinlock_t thermal/x86_pkg_temp: Make pkg_temp_lock a raw_spinlock_t Documentation/locking/locktypes: Minor copy editor fixes Documentation/locking/locktypes: Further clarifications and wordsmithing m68knommu: Remove mm.h include from uaccess_no.h x86: get rid of user_atomic_cmpxchg_inatomic() generic arch_futex_atomic_op_inuser() doesn't need access_ok() x86: don't reload after cmpxchg in unsafe_atomic_op2() loop x86: convert arch_futex_atomic_op_inuser() to user_access_begin/user_access_end() objtool: whitelist __sanitizer_cov_trace_switch() [parisc, s390, sparc64] no need for access_ok() in futex handling sh: no need of access_ok() in arch_futex_atomic_op_inuser() futex: arch_futex_atomic_op_inuser() calling conventions change completion: Use lockdep_assert_RT_in_threaded_ctx() in complete_all() lockdep: Add posixtimer context tracing bits lockdep: Annotate irq_work lockdep: Add hrtimer context tracing bits lockdep: Introduce wait-type checks completion: Use simple wait queues sched/swait: Prepare usage in completions ...
2020-03-27objtool: whitelist __sanitizer_cov_trace_switch()Al Viro
it's not really different from e.g. __sanitizer_cov_trace_cmp4(); as it is, the switches that generate an array of labels get rejected by objtool, while slightly different set of cases that gets compiled into a series of comparisons is accepted. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-03-25objtool: Re-arrange validate_functions()Peter Zijlstra
In preparation to adding a vmlinux.o specific pass, rearrange some code. No functional changes intended. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lkml.kernel.org/r/20200324160924.924304616@infradead.org
2020-03-25objtool: Optimize find_rela_by_dest_range()Peter Zijlstra
Perf shows there is significant time in find_rela_by_dest(); this is because we have to iterate the address space per byte, looking for relocation entries. Optimize this by reducing the address space granularity. This reduces objtool on vmlinux.o runtime from 4.8 to 4.4 seconds. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lkml.kernel.org/r/20200324160924.861321325@infradead.org
2020-03-25objtool: Delete cleanup()Peter Zijlstra
Perf shows we spend a measurable amount of time spend cleaning up right before we exit anyway. Avoid the needsless work and just terminate. This reduces objtool on vmlinux.o runtime from 5.4s to 4.8s Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lkml.kernel.org/r/20200324160924.800720170@infradead.org
2020-03-25objtool: Optimize read_sections()Peter Zijlstra
Perf showed that __hash_init() is a significant portion of read_sections(), so instead of doing a per section rela_hash, use an elf-wide rela_hash. Statistics show us there are about 1.1 million relas, so size it accordingly. This reduces the objtool on vmlinux.o runtime to a third, from 15 to 5 seconds. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lkml.kernel.org/r/20200324160924.739153726@infradead.org
2020-03-25objtool: Optimize find_symbol_by_name()Peter Zijlstra
Perf showed that find_symbol_by_name() takes time; add a symbol name hash. This shaves another second off of objtool on vmlinux.o runtime, down to 15 seconds. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lkml.kernel.org/r/20200324160924.676865656@infradead.org
2020-03-25objtool: Resize insn_hashPeter Zijlstra
Perf shows we're spending a lot of time in find_insn() and the statistics show we have around 3.2 million instruction. Increase the hash table size to reduce the bucket load from around 50 to 3. This shaves about 2s off of objtool on vmlinux.o runtime, down to 16s. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lkml.kernel.org/r/20200324160924.617882545@infradead.org
2020-03-25objtool: Rename find_containing_func()Peter Zijlstra
For consistency; we have: find_symbol_by_offset() / find_symbol_containing() find_func_by_offset() / find_containing_func() fix that. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lkml.kernel.org/r/20200324160924.558470724@infradead.org
2020-03-25objtool: Optimize find_symbol_*() and read_symbols()Peter Zijlstra
All of: read_symbols(), find_symbol_by_offset(), find_symbol_containing(), find_containing_func() do a linear search of the symbols. Add an RB tree to make it go faster. This about halves objtool runtime on vmlinux.o, from 34s to 18s. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lkml.kernel.org/r/20200324160924.499016559@infradead.org
2020-03-25objtool: Optimize find_section_by_name()Peter Zijlstra
In order to avoid yet another linear search of (20k) sections, add a name based hash. This reduces objtool runtime on vmlinux.o by some 10s to around 35s. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lkml.kernel.org/r/20200324160924.440174280@infradead.org
2020-03-25objtool: Optimize find_section_by_index()Peter Zijlstra
In order to avoid a linear search (over 20k entries), add an section_hash to the elf object. This reduces objtool on vmlinux.o from a few minutes to around 45 seconds. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lkml.kernel.org/r/20200324160924.381249993@infradead.org
2020-03-25objtool: Add a statistics modePeter Zijlstra
Have it print a few numbers which can be used to size the hashtables. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lkml.kernel.org/r/20200324160924.321381240@infradead.org
2020-03-25objtool: Optimize find_symbol_by_index()Peter Zijlstra
The symbol index is object wide, not per section, so it makes no sense to have the symbol_hash be part of the section object. By moving it to the elf object we avoid the linear sections iteration. This reduces the runtime of objtool on vmlinux.o from over 3 hours (I gave up) to a few minutes. The defconfig vmlinux.o has around 20k sections. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lkml.kernel.org/r/20200324160924.261852348@infradead.org
2020-03-25objtool: Rename func_for_each_insn_all()Peter Zijlstra
Now that func_for_each_insn() is available, rename func_for_each_insn_all(). This gets us: sym_for_each_insn() - iterate on symbol offset/len func_for_each_insn() - iterate on insn->func Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lkml.kernel.org/r/20200324160924.083720147@infradead.org
2020-03-25objtool: Rename func_for_each_insn()Peter Zijlstra
There is func_for_each_insn() and func_for_each_insn_all(), the both iterate the instructions, but the first uses symbol offset/length while the second uses insn->func. Rename func_for_each_insn() to sym_for_eac_insn() because it iterates on symbol information. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lkml.kernel.org/r/20200324160924.024341229@infradead.org
2020-03-25objtool: Introduce validate_return()Peter Zijlstra
Trivial 'cleanup' to save one indentation level and match validate_call(). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lkml.kernel.org/r/20200324160923.963996225@infradead.org
2020-03-25.gitignore: add SPDX License IdentifierMasahiro Yamada
Add SPDX License Identifier to all .gitignore files. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-21Merge branch 'x86/kdump' into locking/kcsan, to resolve conflictsIngo Molnar
Conflicts: arch/x86/purgatory/Makefile Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-02-21objtool: Improve call destination function detectionJosh Poimboeuf
A recent clang change, combined with a binutils bug, can trigger a situation where a ".Lprintk$local" STT_NOTYPE symbol gets created at the same offset as the "printk" STT_FUNC symbol. This confuses objtool: kernel/printk/printk.o: warning: objtool: ignore_loglevel_setup()+0x10: can't find call dest symbol at .text+0xc67 Improve the call destination detection by looking specifically for an STT_FUNC symbol. Reported-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nathan Chancellor <natechancellor@gmail.com> Link: https://github.com/ClangBuiltLinux/linux/issues/872 Link: https://sourceware.org/bugzilla/show_bug.cgi?id=25551 Link: https://lkml.kernel.org/r/0a7ee320bc0ea4469bd3dc450a7b4725669e0ea9.1581997059.git.jpoimboe@redhat.com
2020-02-21objtool: Fix clang switch table edge caseJosh Poimboeuf
Clang has the ability to create a switch table which is not a jump table, but is rather a table of string pointers. This confuses objtool, because it sees the relocations for the string pointers and assumes they're part of a jump table: drivers/ata/sata_dwc_460ex.o: warning: objtool: sata_dwc_bmdma_start_by_tag()+0x3a2: can't find switch jump table net/ceph/messenger.o: warning: objtool: ceph_con_workfn()+0x47c: can't find switch jump table Make objtool's find_jump_table() smart enough to distinguish between a switch jump table (which has relocations to text addresses in the same function as the original instruction) and other anonymous rodata (which may have relocations to elsewhere). Reported-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nathan Chancellor <natechancellor@gmail.com> Link: https://github.com/ClangBuiltLinux/linux/issues/485 Link: https://lkml.kernel.org/r/263f6aae46d33da0b86d7030ced878cb5cab1788.1581997059.git.jpoimboe@redhat.com
2020-02-11objtool: Add relocation check for alternative sectionsJosh Poimboeuf
Relocations in alternative code can be dangerous, because the code is copy/pasted to the text section after relocations have been resolved, which can corrupt PC-relative addresses. However, relocations might be acceptable in some cases, depending on the architecture. For example, the x86 alternatives code manually fixes up the target addresses for PC-relative jumps and calls. So disallow relocations in alternative code, except where the x86 arch code allows it. This code may need to be tweaked for other arches when objtool gets support for them. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Julien Thierry <jthierry@redhat.com> Link: https://lkml.kernel.org/r/7b90b68d093311e4e8f6b504a9e1c758fd7e0002.1581359535.git.jpoimboe@redhat.com
2020-02-11objtool: Add is_static_jump() helperJosh Poimboeuf
There are several places where objtool tests for a non-dynamic (aka direct) jump. Move the check to a helper function. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Julien Thierry <jthierry@redhat.com> Link: https://lkml.kernel.org/r/9b8b438df918276315e4765c60d2587f3c7ad698.1581359535.git.jpoimboe@redhat.com
2020-02-11objtool: Fail the kernel build on fatal errorsJosh Poimboeuf
When objtool encounters a fatal error, it usually means the binary is corrupt or otherwise broken in some way. Up until now, such errors were just treated as warnings which didn't fail the kernel build. However, objtool is now stable enough that if a fatal error is discovered, it most likely means something is seriously wrong and it should fail the kernel build. Note that this doesn't apply to "normal" objtool warnings; only fatal ones. Suggested-by: Borislav Petkov <bp@suse.de> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Julien Thierry <jthierry@redhat.com> Link: https://lkml.kernel.org/r/f18c3743de0fef673d49dd35760f26bdef7f6fc3.1581359535.git.jpoimboe@redhat.com
2020-01-22objtool: Fix ARCH=x86_64 build errorShile Zhang
Building objtool with ARCH=x86_64 fails with: $make ARCH=x86_64 -C tools/objtool ... CC arch/x86/decode.o arch/x86/decode.c:10:22: fatal error: asm/insn.h: No such file or directory #include <asm/insn.h> ^ compilation terminated. mv: cannot stat ‘arch/x86/.decode.o.tmp’: No such file or directory make[2]: *** [arch/x86/decode.o] Error 1 ... The root cause is that the command-line variable 'ARCH' cannot be overridden. It can be replaced by 'SRCARCH', which is defined in 'tools/scripts/Makefile.arch'. Signed-off-by: Shile Zhang <shile.zhang@linux.alibaba.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Link: https://lore.kernel.org/r/d5d11370ae116df6c653493acd300ec3d7f5e925.1579543924.git.jpoimboe@redhat.com
2020-01-22objtool: Silence build outputOlof Johansson
The sync-check.sh script prints out the path due to a "cd -" at the end of the script, even on silent builds. This isn't even needed, since the script is executed in our build instead of sourced (so it won't change the working directory of the surrounding build anyway). Just remove the cd to make the build silent. Fixes: 2ffd84ae973b ("objtool: Update sync-check.sh from perf's check-headers.sh") Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/cb002857fafa8186cfb9c3e43fb62e4108a1bab9.1579543924.git.jpoimboe@redhat.com
2019-12-30Merge tag 'v5.5-rc4' into locking/kcsan, to resolve conflictsIngo Molnar
Conflicts: init/main.c lib/Kconfig.debug Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-11-26Merge branch 'perf-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf updates from Ingo Molnar: "The main kernel side changes in this cycle were: - Various Intel-PT updates and optimizations (Alexander Shishkin) - Prohibit kprobes on Xen/KVM emulate prefixes (Masami Hiramatsu) - Add support for LSM and SELinux checks to control access to the perf syscall (Joel Fernandes) - Misc other changes, optimizations, fixes and cleanups - see the shortlog for details. There were numerous tooling changes as well - 254 non-merge commits. Here are the main changes - too many to list in detail: - Enhancements to core tooling infrastructure, perf.data, libperf, libtraceevent, event parsing, vendor events, Intel PT, callchains, BPF support and instruction decoding. - There were updates to the following tools: perf annotate perf diff perf inject perf kvm perf list perf maps perf parse perf probe perf record perf report perf script perf stat perf test perf trace - And a lot of other changes: please see the shortlog and Git log for more details" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (279 commits) perf parse: Fix potential memory leak when handling tracepoint errors perf probe: Fix spelling mistake "addrees" -> "address" libtraceevent: Fix memory leakage in copy_filter_type libtraceevent: Fix header installation perf intel-bts: Does not support AUX area sampling perf intel-pt: Add support for decoding AUX area samples perf intel-pt: Add support for recording AUX area samples perf pmu: When using default config, record which bits of config were changed by the user perf auxtrace: Add support for queuing AUX area samples perf session: Add facility to peek at all events perf auxtrace: Add support for dumping AUX area samples perf inject: Cut AUX area samples perf record: Add aux-sample-size config term perf record: Add support for AUX area sampling perf auxtrace: Add support for AUX area sample recording perf auxtrace: Move perf_evsel__find_pmu() perf record: Add a function to test for kernel support for AUX area sampling perf tools: Add kernel AUX area sampling definitions perf/core: Make the mlock accounting simple again perf report: Jump to symbol source view from total cycles view ...
2019-11-26Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 asm updates from Ingo Molnar: "The main changes in this cycle were: - Cross-arch changes to move the linker sections for NOTES and EXCEPTION_TABLE into the RO_DATA area, where they belong on most architectures. (Kees Cook) - Switch the x86 linker fill byte from x90 (NOP) to 0xcc (INT3), to trap jumps into the middle of those padding areas instead of sliding execution. (Kees Cook) - A thorough cleanup of symbol definitions within x86 assembler code. The rather randomly named macros got streamlined around a (hopefully) straightforward naming scheme: SYM_START(name, linkage, align...) SYM_END(name, sym_type) SYM_FUNC_START(name) SYM_FUNC_END(name) SYM_CODE_START(name) SYM_CODE_END(name) SYM_DATA_START(name) SYM_DATA_END(name) etc - with about three times of these basic primitives with some label, local symbol or attribute variant, expressed via postfixes. No change in functionality intended. (Jiri Slaby) - Misc other changes, cleanups and smaller fixes" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (67 commits) x86/entry/64: Remove pointless jump in paranoid_exit x86/entry/32: Remove unused resume_userspace label x86/build/vdso: Remove meaningless CFLAGS_REMOVE_*.o m68k: Convert missed RODATA to RO_DATA x86/vmlinux: Use INT3 instead of NOP for linker fill bytes x86/mm: Report actual image regions in /proc/iomem x86/mm: Report which part of kernel image is freed x86/mm: Remove redundant address-of operators on addresses xtensa: Move EXCEPTION_TABLE to RO_DATA segment powerpc: Move EXCEPTION_TABLE to RO_DATA segment parisc: Move EXCEPTION_TABLE to RO_DATA segment microblaze: Move EXCEPTION_TABLE to RO_DATA segment ia64: Move EXCEPTION_TABLE to RO_DATA segment h8300: Move EXCEPTION_TABLE to RO_DATA segment c6x: Move EXCEPTION_TABLE to RO_DATA segment arm64: Move EXCEPTION_TABLE to RO_DATA segment alpha: Move EXCEPTION_TABLE to RO_DATA segment x86/vmlinux: Move EXCEPTION_TABLE to RO_DATA segment x86/vmlinux: Actually use _etext for the end of the text segment vmlinux.lds.h: Allow EXCEPTION_TABLE to live in RO_DATA ...
2019-11-16objtool, kcsan: Add KCSAN runtime functions to whitelistMarco Elver
This patch adds KCSAN runtime functions to the objtool whitelist. Signed-off-by: Marco Elver <elver@google.com> Acked-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>