aboutsummaryrefslogtreecommitdiff
path: root/tools/objtool
AgeCommit message (Collapse)AuthorFilesLines
2020-04-22objtool: Implement noinstr validationPeter Zijlstra5-4/+112
Validate that any call out of .noinstr.text is in between instr_begin() and instr_end() annotations. This annotation is useful to ensure correct behaviour wrt tracing sensitive code like entry/exit and idle code. When we run code in a sensitive context we want a guarantee no unknown code is ran. Since this validation relies on knowing the section of call destination symbols, we must run it on vmlinux.o instead of on individual object files. Add two options: -d/--duplicate "duplicate validation for vmlinux" -l/--vmlinux "vmlinux.o validation" Where the latter auto-detects when objname ends with "vmlinux.o" and the former will force all validations, also those already done on !vmlinux object files. Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Josh Poimboeuf <[email protected]> Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2020-04-22objtool: Fix !CFI insn_state propagationPeter Zijlstra4-140/+157
Objtool keeps per instruction CFI state in struct insn_state and will save/restore this where required. However, insn_state has grown some !CFI state, and this must not be saved/restored (that would loose/destroy state). Fix this by moving the CFI specific parts of insn_state into struct cfi_state. Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Josh Poimboeuf <[email protected]> Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2020-04-22objtool: Rename struct cfi_statePeter Zijlstra4-4/+4
There's going to be a new struct cfi_state, rename this one to make place. Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Josh Poimboeuf <[email protected]> Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2020-04-22objtool: Remove SAVE/RESTORE hintsPeter Zijlstra2-40/+4
The SAVE/RESTORE hints are now unused; remove them. Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Josh Poimboeuf <[email protected]> Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2020-04-22objtool: Introduce HINT_RET_OFFSETPeter Zijlstra2-9/+19
Normally objtool ensures a function keeps the stack layout invariant. But there is a useful exception, it is possible to stuff the return stack in order to 'inject' a 'call': push $fun ret In this case the invariant mentioned above is violated. Add an objtool HINT to annotate this and allow a function exit with a modified stack frame. Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Josh Poimboeuf <[email protected]> Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2020-04-22objtool: Better handle IRETPeter Zijlstra3-15/+29
Teach objtool a little more about IRET so that we can avoid using the SAVE/RESTORE annotation. In particular, make the weird corner case in insn->restore go away. The purpose of that corner case is to deal with the fact that UNWIND_HINT_RESTORE lands on the instruction after IRET, but that instruction can end up being outside the basic block, consider: if (cond) sync_core() foo(); Then the hint will land on foo(), and we'll encounter the restore hint without ever having seen the save hint. By teaching objtool about the arch specific exception frame size, and assuming that any IRET in an STT_FUNC symbol is an exception frame sized POP, we can remove the use of save/restore hints for this code. Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Josh Poimboeuf <[email protected]> Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2020-04-22objtool: Support multiple stack_op per instructionJulien Thierry4-31/+62
Instruction sets can include more or less complex operations which might not fit the currently defined set of stack_ops. Combining more than one stack_op provides more flexibility to describe the behaviour of an instruction. This also reduces the need to define new stack_ops specific to a single instruction set. Allow instruction decoders to generate multiple stack_op per instruction. Signed-off-by: Julien Thierry <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Reviewed-by: Alexandre Chartre <[email protected]> Acked-by: Josh Poimboeuf <[email protected]> Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2020-04-22objtool: Remove redundant .rodata section name comparisonMuchun Song1-2/+2
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 <[email protected]> Signed-off-by: Josh Poimboeuf <[email protected]> Signed-off-by: Ingo Molnar <[email protected]>
2020-04-22objtool: Documentation: document UACCESS warningsNick Desaulniers1-0/+26
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 <[email protected]> Suggested-by: Matt Helsley <[email protected]> Suggested-by: Peter Zijlstra <[email protected]> Suggested-by: Randy Dunlap <[email protected]> Signed-off-by: Nick Desaulniers <[email protected]> Signed-off-by: Josh Poimboeuf <[email protected]> Signed-off-by: Ingo Molnar <[email protected]>
2020-04-22objtool: Split out arch-specific CFI definitionsJulien Thierry3-20/+29
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 <[email protected]> Acked-by: Peter Zijlstra (Intel) <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Signed-off-by: Josh Poimboeuf <[email protected]> Signed-off-by: Ingo Molnar <[email protected]>
2020-04-22objtool: Add abstraction for destination offsetsRaphael Gault3-8/+27
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 <[email protected]> Signed-off-by: Julien Thierry <[email protected]> Acked-by: Peter Zijlstra (Intel) <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Signed-off-by: Josh Poimboeuf <[email protected]> Signed-off-by: Ingo Molnar <[email protected]>
2020-04-22objtool: Use arch specific values in restore_reg()Julien Thierry1-2/+2
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 <[email protected]> Signed-off-by: Julien Thierry <[email protected]> Acked-by: Peter Zijlstra (Intel) <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Signed-off-by: Josh Poimboeuf <[email protected]> Signed-off-by: Ingo Molnar <[email protected]>
2020-04-22objtool: Ignore empty alternativesJulien Thierry1-0/+6
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 <[email protected]> Acked-by: Peter Zijlstra (Intel) <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Signed-off-by: Josh Poimboeuf <[email protected]> Signed-off-by: Ingo Molnar <[email protected]>
2020-04-22objtool: Clean instruction state before each function validationJulien Thierry1-7/+6
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 <[email protected]> Acked-by: Peter Zijlstra (Intel) <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Signed-off-by: Josh Poimboeuf <[email protected]> Signed-off-by: Ingo Molnar <[email protected]>
2020-04-22objtool: Remove redundant checks on operand typeJulien Thierry1-3/+1
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 <[email protected]> Acked-by: Peter Zijlstra (Intel) <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Signed-off-by: Josh Poimboeuf <[email protected]> Signed-off-by: Ingo Molnar <[email protected]>
2020-04-22objtool: Always do header sync checkJulien Thierry1-1/+1
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 <[email protected]> Acked-by: Peter Zijlstra (Intel) <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Signed-off-by: Josh Poimboeuf <[email protected]> Signed-off-by: Ingo Molnar <[email protected]>
2020-04-22objtool: Fix off-by-one in symbol_by_offset()Julien Thierry1-1/+1
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 <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Signed-off-by: Josh Poimboeuf <[email protected]> Signed-off-by: Ingo Molnar <[email protected]>
2020-04-22objtool: Fix 32bit cross buildsPeter Zijlstra1-1/+1
Apparently there's people doing 64bit builds on 32bit machines. Fixes: 74b873e49d92 ("objtool: Optimize find_rela_by_dest_range()") Reported-by: [email protected] Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Signed-off-by: Ingo Molnar <[email protected]>
2020-04-14objtool: Make BP scratch register warning more robustJosh Poimboeuf1-2/+2
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 <[email protected]> Signed-off-by: Josh Poimboeuf <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Link: https://lkml.kernel.org/r/afc628693a37acd287e843bcc5c0430263d93c74.1585761021.git.jpoimboe@redhat.com
2020-04-14objtool: Fix switch table detection in .text.unlikelyJosh Poimboeuf1-4/+1
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 <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Acked-by: Peter Zijlstra (Intel) <[email protected]> Link: https://lkml.kernel.org/r/157c35d42ca9b6354bbb1604fe9ad7d1153ccb21.1585761021.git.jpoimboe@redhat.com
2020-04-14objtool: Support Clang non-section symbols in ORC generationJosh Poimboeuf1-7/+26
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 <[email protected]> Signed-off-by: Josh Poimboeuf <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Tested-by: Nathan Chancellor <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Acked-by: Peter Zijlstra (Intel) <[email protected]> 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 Poimboeuf1-17/+27
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 <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Acked-by: Peter Zijlstra (Intel) <[email protected]> Link: https://lkml.kernel.org/r/b811b5eb1a42602c3b523576dc5efab9ad1c174d.1585761021.git.jpoimboe@redhat.com
2020-04-14objtool: Fix CONFIG_UBSAN_TRAP unreachable warningsJosh Poimboeuf1-2/+15
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 <[email protected]> Signed-off-by: Josh Poimboeuf <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Reviewed-by: Kees Cook <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Acked-by: Peter Zijlstra (Intel) <[email protected]> Link: https://lkml.kernel.org/r/6653ad73c6b59c049211bd7c11ed3809c20ee9f5.1585761021.git.jpoimboe@redhat.com
2020-04-13objtool, kcsan: Add explicit check functions to uaccess whitelistMarco Elver1-0/+2
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 <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2020-04-13Merge tag 'v5.7-rc1' into locking/kcsan, to resolve conflicts and refreshIngo Molnar12-206/+429
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 <[email protected]>
2020-04-09kbuild: support LLVM=1 to switch the default tools to Clang/LLVMMasahiro Yamada1-0/+6
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 <[email protected]> Reviewed-by: Nathan Chancellor <[email protected]> Tested-by: Nathan Chancellor <[email protected]> # build Tested-by: Nick Desaulniers <[email protected]> Reviewed-by: Nick Desaulniers <[email protected]>
2020-04-03Merge tag 'spdx-5.7-rc1' of ↵Linus Torvalds1-0/+1
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 Torvalds1-0/+1
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 Viro1-0/+1
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 <[email protected]>
2020-03-25objtool: Re-arrange validate_functions()Peter Zijlstra1-22/+30
In preparation to adding a vmlinux.o specific pass, rearrange some code. No functional changes intended. Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Acked-by: Josh Poimboeuf <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-03-25objtool: Optimize find_rela_by_dest_range()Peter Zijlstra2-5/+26
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) <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Acked-by: Josh Poimboeuf <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-03-25objtool: Delete cleanup()Peter Zijlstra1-19/+0
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) <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Acked-by: Josh Poimboeuf <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-03-25objtool: Optimize read_sections()Peter Zijlstra5-29/+47
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) <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Acked-by: Josh Poimboeuf <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-03-25objtool: Optimize find_symbol_by_name()Peter Zijlstra2-5/+7
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) <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Acked-by: Josh Poimboeuf <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-03-25objtool: Resize insn_hashPeter Zijlstra1-1/+1
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) <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Acked-by: Josh Poimboeuf <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-03-25objtool: Rename find_containing_func()Peter Zijlstra3-3/+3
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) <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Acked-by: Josh Poimboeuf <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-03-25objtool: Optimize find_symbol_*() and read_symbols()Peter Zijlstra3-58/+144
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) <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Acked-by: Josh Poimboeuf <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-03-25objtool: Optimize find_section_by_name()Peter Zijlstra2-1/+12
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) <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Acked-by: Josh Poimboeuf <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-03-25objtool: Optimize find_section_by_index()Peter Zijlstra2-5/+10
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) <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Acked-by: Josh Poimboeuf <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-03-25objtool: Add a statistics modePeter Zijlstra4-3/+25
Have it print a few numbers which can be used to size the hashtables. Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Acked-by: Josh Poimboeuf <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-03-25objtool: Optimize find_symbol_by_index()Peter Zijlstra2-10/+6
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) <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Acked-by: Josh Poimboeuf <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-03-25objtool: Rename func_for_each_insn_all()Peter Zijlstra1-6/+6
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) <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Acked-by: Josh Poimboeuf <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-03-25objtool: Rename func_for_each_insn()Peter Zijlstra1-8/+8
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) <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Acked-by: Josh Poimboeuf <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-03-25objtool: Introduce validate_return()Peter Zijlstra1-28/+36
Trivial 'cleanup' to save one indentation level and match validate_call(). Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Reviewed-by: Miroslav Benes <[email protected]> Acked-by: Josh Poimboeuf <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-03-25.gitignore: add SPDX License IdentifierMasahiro Yamada1-0/+1
Add SPDX License Identifier to all .gitignore files. Signed-off-by: Masahiro Yamada <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
2020-03-21Merge branch 'x86/kdump' into locking/kcsan, to resolve conflictsIngo Molnar2-7/+1
Conflicts: arch/x86/purgatory/Makefile Signed-off-by: Ingo Molnar <[email protected]>
2020-02-21objtool: Improve call destination function detectionJosh Poimboeuf3-11/+31
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 <[email protected]> Signed-off-by: Josh Poimboeuf <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Tested-by: Nick Desaulniers <[email protected]> Tested-by: Nathan Chancellor <[email protected]> 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 Poimboeuf1-2/+9
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 <[email protected]> Signed-off-by: Josh Poimboeuf <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Tested-by: Nick Desaulniers <[email protected]> Tested-by: Nathan Chancellor <[email protected]> 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 Poimboeuf1-0/+21
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 <[email protected]> Signed-off-by: Josh Poimboeuf <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Reviewed-by: Julien Thierry <[email protected]> Link: https://lkml.kernel.org/r/7b90b68d093311e4e8f6b504a9e1c758fd7e0002.1581359535.git.jpoimboe@redhat.com
2020-02-11objtool: Add is_static_jump() helperJosh Poimboeuf1-6/+9
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 <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Reviewed-by: Julien Thierry <[email protected]> Link: https://lkml.kernel.org/r/9b8b438df918276315e4765c60d2587f3c7ad698.1581359535.git.jpoimboe@redhat.com
Powered by cgit, Gruvboxed by Blaster4385.