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2022-04-22objtool: Rename "VMLINUX_VALIDATION" -> "NOINSTR_VALIDATION"Josh Poimboeuf1-3/+3
CONFIG_VMLINUX_VALIDATION is just the validation of the "noinstr" rules. That name is a misnomer, because now objtool actually does vmlinux validation for other reasons. Rename CONFIG_VMLINUX_VALIDATION to CONFIG_NOINSTR_VALIDATION. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Link: https://lkml.kernel.org/r/173f07e2d6d1afc0874aed975a61783207c6a531.1650300597.git.jpoimboe@redhat.com
2022-04-22objtool: Add CONFIG_OBJTOOLJosh Poimboeuf1-3/+3
Now that stack validation is an optional feature of objtool, add CONFIG_OBJTOOL and replace most usages of CONFIG_STACK_VALIDATION with it. CONFIG_STACK_VALIDATION can now be considered to be frame-pointer specific. CONFIG_UNWINDER_ORC is already inherently valid for live patching, so no need to "validate" it. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Link: https://lkml.kernel.org/r/939bf3d85604b2a126412bf11af6e3bd3b872bcb.1650300597.git.jpoimboe@redhat.com
2021-12-22compiler.h: Fix annotation macro misplacement with ClangJosh Poimboeuf1-2/+2
When building with Clang and CONFIG_TRACE_BRANCH_PROFILING, there are a lot of unreachable warnings, like: arch/x86/kernel/traps.o: warning: objtool: handle_xfd_event()+0x134: unreachable instruction Without an input to the inline asm, 'volatile' is ignored for some reason and Clang feels free to move the reachable() annotation away from its intended location. Fix that by re-adding the counter value to the inputs. Fixes: f1069a8756b9 ("compiler.h: Avoid using inline asm operand modifiers") Fixes: c199f64ff93c ("instrumentation.h: Avoid using inline asm operand modifiers") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/0417e96909b97a406323409210de7bf13df0b170.1636410380.git.jpoimboe@redhat.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: x86@kernel.org Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Miroslav Benes <mbenes@suse.cz>
2021-05-19instrumentation.h: Avoid using inline asm operand modifiersVasily Gorbik1-8/+12
The expansion of instrumentation_begin/instrumentation_end on s390 will result in a compiler error if the __COUNTER__ value is high enough. For example with "i" (154) the "%c0" operand of annotate_reachable will be expanded to -102: -102: .pushsection .discard.instr_begin .long -102b - . .popsection This is a quirk of the gcc backend for s390, it interprets the %c0 as a signed byte value. Avoid using operand modifiers in this case by simply converting __COUNTER__ to string, with the same result, but in an arch assembler independent way. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/patch-2.thread-1a26be.git-1a26be80cb18.your-ad-here.call-01621428935-ext-2104@work.hours Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Borislav Petkov <bp@suse.de> Cc: linux-kernel@vger.kernel.org
2020-07-24compiler.h: Move instrumentation_begin()/end() to new ↵Ingo Molnar1-0/+57
<linux/instrumentation.h> header Linus pointed out that compiler.h - which is a key header that gets included in every single one of the 28,000+ kernel files during a kernel build - was bloated in: 655389666643: ("vmlinux.lds.h: Create section for protection against instrumentation") Linus noted: > I have pulled this, but do we really want to add this to a header file > that is _so_ core that it gets included for basically every single > file built? > > I don't even see those instrumentation_begin/end() things used > anywhere right now. > > It seems excessive. That 53 lines is maybe not a lot, but it pushed > that header file to over 12kB, and while it's mostly comments, it's > extra IO and parsing basically for _every_ single file compiled in the > kernel. > > For what appears to be absolutely zero upside right now, and I really > don't see why this should be in such a core header file! Move these primitives into a new header: <linux/instrumentation.h>, and include that header in the headers that make use of it. Unfortunately one of these headers is asm-generic/bug.h, which does get included in a lot of places, similarly to compiler.h. So the de-bloating effect isn't as good as we'd like it to be - but at least the interfaces are defined separately. No change to functionality intended. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20200604071921.GA1361070@gmail.com Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Peter Zijlstra <peterz@infradead.org>