summaryrefslogtreecommitdiffstats
path: root/tools/objtool (follow)
Commit message (Collapse)AuthorAgeFilesLines
* tools/headers: Sync objtool UAPI headerIngo Molnar2017-11-141-0/+10
| | | | | | | | | | | | | | | | | objtool grew this new warning: Warning: synced file at 'tools/objtool/arch/x86/include/asm/inat.h' differs from latest kernel version at 'arch/x86/include/asm/inat.h' which upstream header grew new INAT_SEG_* definitions. Sync up the tooling version of the header. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Fix cross-buildJosh Poimboeuf2017-11-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | Stephen Rothwell reported this cross-compilation build failure: | In file included from orc_dump.c:19:0: | orc.h:21:10: fatal error: asm/orc_types.h: No such file or directory | ... Caused by: 6a77cff819ae ("objtool: Move synced files to their original relative locations") Use the proper arch header files location, not the host-arch location. Bisected-by: Stephen Rothwell <sfr@canb.auug.org.au> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Linux-Next Mailing List <linux-next@vger.kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20171108030152.bd76eahiwjwjt3kp@treble Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Move kernel headers/code sync check to a scriptJosh Poimboeuf2017-11-072-15/+30
| | | | | | | | | | | | | | | Replace the nasty diff checks in the objtool Makefile with a clean bash script, and make the warnings more specific. Heavily inspired by tools/perf/check-headers.sh. Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/ab015f15ccd8c0c6008493c3c6ee3d495eaf2927.1509974346.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Move synced files to their original relative locationsJosh Poimboeuf2017-11-0713-25/+27
| | | | | | | | | | | | | This will enable more straightforward comparisons, and it also makes the files 100% identical. Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/407b2aaa317741f48fcf821592c0e96ab3be1890.1509974346.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Merge branch 'linus' into core/objtool, to pick up dependent fixesIngo Molnar2017-11-073-2/+9
|\ | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * objtool: Resync objtool's instruction decoder source code copy with the ↵Josh Poimboeuf2017-11-041-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kernel's latest version This fixes the following warning: warning: objtool: x86 instruction decoder differs from kernel Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/013315a808ccf5580abc293808827c8e2b5e1354.1509719152.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman2017-11-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * objtool: Fix memory leak in decode_instructions()Kamalesh Babulal2017-10-201-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | When an error occurs before adding an allocated insn to the list, free it before returning. Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/336da800bf6070eae11f4e0a3b9ca64c27658114.1508430423.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | objtool: Print top level commands on incorrect usageKamalesh Babulal2017-10-181-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Print top-level objtool commands, along with the error on incorrect command line usage. Objtool command line parser exit's with code 129, for incorrect usage. Convert the cmd_usage() exit code also, to maintain consistency across objtool. After the patch: $ ./objtool -j Unknown option: -j usage: objtool COMMAND [ARGS] Commands: check Perform stack metadata validation on an object file orc Generate in-place ORC unwind tables for an object file $ echo $? 129 Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1507992474-16142-1-git-send-email-kamalesh@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | objtool: Don't report end of section error after an empty unwind hintJosh Poimboeuf2017-09-281-2/+5
|/ | | | | | | | | | | | | | | | | If asm code specifies an UNWIND_HINT_EMPTY hint, don't warn if the section ends unexpectedly. This can happen with the xen-head.S code because the hypercall_page is "text" but it's all zeros. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/ddafe199dd8797e40e3c2777373347eba1d65572.1505764066.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Support unoptimized frame pointer setupJosh Poimboeuf2017-09-281-3/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Arnd Bergmann reported a bunch of warnings like: crypto/jitterentropy.o: warning: objtool: jent_fold_time()+0x3b: call without frame pointer save/setup crypto/jitterentropy.o: warning: objtool: jent_stuck()+0x1d: call without frame pointer save/setup crypto/jitterentropy.o: warning: objtool: jent_unbiased_bit()+0x15: call without frame pointer save/setup crypto/jitterentropy.o: warning: objtool: jent_read_entropy()+0x32: call without frame pointer save/setup crypto/jitterentropy.o: warning: objtool: jent_entropy_collector_free()+0x19: call without frame pointer save/setup and arch/x86/events/core.o: warning: objtool: collect_events uses BP as a scratch register arch/x86/events/core.o: warning: objtool: events_ht_sysfs_show()+0x22: call without frame pointer save/setup With certain rare configurations, GCC sometimes sets up the frame pointer with: lea (%rsp),%rbp instead of: mov %rsp,%rbp The instructions are equivalent, so treat the former like the latter. Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/a468af8b28a69b83fffc6d7668be9b6fcc873699.1506526584.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/asm: Fix inline asm call constraints for ClangJosh Poimboeuf2017-09-231-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For inline asm statements which have a CALL instruction, we list the stack pointer as a constraint to convince GCC to ensure the frame pointer is set up first: static inline void foo() { register void *__sp asm(_ASM_SP); asm("call bar" : "+r" (__sp)) } Unfortunately, that pattern causes Clang to corrupt the stack pointer. The fix is easy: convert the stack pointer register variable to a global variable. It should be noted that the end result is different based on the GCC version. With GCC 6.4, this patch has exactly the same result as before: defconfig defconfig-nofp distro distro-nofp before 9820389 9491555 8816046 8516940 after 9820389 9491555 8816046 8516940 With GCC 7.2, however, GCC's behavior has changed. It now changes its behavior based on the conversion of the register variable to a global. That somehow convinces it to *always* set up the frame pointer before inserting *any* inline asm. (Therefore, listing the variable as an output constraint is a no-op and is no longer necessary.) It's a bit overkill, but the performance impact should be negligible. And in fact, there's a nice improvement with frame pointers disabled: defconfig defconfig-nofp distro distro-nofp before 9796316 9468236 9076191 8790305 after 9796957 9464267 9076381 8785949 So in summary, while listing the stack pointer as an output constraint is no longer necessary for newer versions of GCC, it's still needed for older versions. Suggested-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Reported-by: Matthias Kaehlcke <mka@chromium.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Miguel Bernal Marin <miguel.bernal.marin@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/3db862e970c432ae823cf515c52b54fec8270e0e.1505942196.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Handle another GCC stack pointer adjustment bugJosh Poimboeuf2017-09-232-17/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The kbuild bot reported the following warning with GCC 4.4 and a randconfig: net/socket.o: warning: objtool: compat_sock_ioctl()+0x1083: stack state mismatch: cfa1=7+160 cfa2=-1+0 This is caused by another GCC non-optimization, where it backs up and restores the stack pointer for no apparent reason: 2f91: 48 89 e0 mov %rsp,%rax 2f94: 4c 89 e7 mov %r12,%rdi 2f97: 4c 89 f6 mov %r14,%rsi 2f9a: ba 20 00 00 00 mov $0x20,%edx 2f9f: 48 89 c4 mov %rax,%rsp This issue would have been happily ignored before the following commit: dd88a0a0c861 ("objtool: Handle GCC stack pointer adjustment bug") But now that objtool is paying attention to such stack pointer writes to/from a register, it needs to understand them properly. In this case that means recognizing that the "mov %rsp, %rax" instruction is potentially a backup of the stack pointer. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matthias Kaehlcke <mka@chromium.org> Cc: Miguel Bernal Marin <miguel.bernal.marin@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: dd88a0a0c861 ("objtool: Handle GCC stack pointer adjustment bug") Link: http://lkml.kernel.org/r/8c7aa8e9a36fbbb6655d9d8e7cea58958c912da8.1505942196.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Fix object file corruptionJosh Poimboeuf2017-09-151-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Arnd Bergmann reported that a randconfig build was failing with the following link error: built-in.o: member arch/x86/kernel/time.o in archive is not an object It turns out the link failed because the time.o file had been corrupted by objtool: nm: arch/x86/kernel/time.o: File format not recognized In certain rare cases, when a .o file's ORC table is very small, the .data section size doesn't change because it's page aligned. Because all the existing sections haven't changed size, libelf doesn't detect any section header changes, and so it doesn't update the section header table properly. Instead it writes junk in the section header entries for the new ORC sections. Make sure libelf properly updates the section header table by setting the ELF_F_DIRTY flag in the top level elf struct. Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 627fce14809b ("objtool: Add ORC unwind table generation") Link: http://lkml.kernel.org/r/e650fd0f2d8a209d1409a9785deb101fdaed55fb.1505459813.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Do not retrieve data from empty sectionsPetr Vandrovec2017-09-151-12/+13
| | | | | | | | | | | | | | | | | | | Binutils 2.29-9 in Debian return an error when elf_getdata is invoked on empty section (.note.GNU-stack in all kernel files), causing immediate failure of kernel build with: elf_getdata: can't manipulate null section As nothing is done with sections that have zero size, just do not retrieve their data at all. Signed-off-by: Petr Vandrovec <petr@vandrovec.name> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/2ce30a44349065b70d0f00e71e286dc0cbe745e6.1505459652.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Fix memory leak in elf_create_rela_section()Martin Kepplinger2017-09-151-0/+1
| | | | | | | | | | | | | | Let's free the allocated char array 'relaname' before returning, in order to avoid leaking memory. Signed-off-by: Martin Kepplinger <martink@posteo.de> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: mingo.kernel.org@gmail.com Link: http://lkml.kernel.org/r/20170914060138.26472-1-martink@posteo.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Handle GCC stack pointer adjustment bugJosh Poimboeuf2017-08-304-90/+88
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Arnd Bergmann reported the following warning with GCC 7.1.1: fs/fs_pin.o: warning: objtool: pin_kill()+0x139: stack state mismatch: cfa1=7+88 cfa2=7+96 And the kbuild robot reported the following warnings with GCC 5.4.1: fs/fs_pin.o: warning: objtool: pin_kill()+0x182: return with modified stack frame fs/quota/dquot.o: warning: objtool: dquot_alloc_inode()+0x140: stack state mismatch: cfa1=7+120 cfa2=7+128 fs/quota/dquot.o: warning: objtool: dquot_free_inode()+0x11a: stack state mismatch: cfa1=7+112 cfa2=7+120 Those warnings are caused by an unusual GCC non-optimization where it uses an intermediate register to adjust the stack pointer. It does: lea 0x8(%rsp), %rcx ... mov %rcx, %rsp Instead of the obvious: add $0x8, %rsp It makes no sense to use an intermediate register, so I opened a GCC bug to track it: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81813 But it's not exactly a high-priority bug and it looks like we'll be stuck with this issue for a while. So for now we have to track register values when they're loaded with stack pointer offsets. This is kind of a big workaround for a tiny problem, but c'est la vie. I hope to eventually create a GCC plugin to implement a big chunk of objtool's functionality. Hopefully at that point we'll be able to remove of a lot of these GCC-isms from the objtool code. Reported-by: Arnd Bergmann <arnd@arndb.de> Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/6a41a96884c725e7f05413bb7df40cfe824b2444.1504028945.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Fix objtool fallthrough detection with function paddingJosh Poimboeuf2017-08-211-7/+7
| | | | | | | | | | | | | | | | | | | | | | When GCC adds NOP padding between functions, those NOPs aren't associated with a function symbol, which breaks objtool's detection of a function falling through to another function. Instead it shows confusing errors like: drivers/mtd/chips/cfi_util.o: warning: objtool: cfi_qry_mode_on()+0x8b: return with modified stack frame drivers/mtd/chips/cfi_util.o: warning: objtool: cfi_qry_mode_on()+0x0: stack state mismatch: cfa1=-4-32 cfa2=7+8 drivers/mtd/chips/cfi_cmdset_0002.o: warning: objtool: fixup_use_fwh_lock()+0x8: unknown stack-related register move drivers/mtd/chips/cfi_cmdset_0002.o: warning: objtool: fixup_use_fwh_lock()+0x0: stack state mismatch: cfa1=6+16 cfa2=7+8 drivers/mtd/chips/cfi_cmdset_0002.o: warning: objtool: do_otp_write()+0xa: unsupported stack pointer realignment drivers/mtd/chips/cfi_cmdset_0002.o: warning: objtool: do_otp_write()+0x0: stack state mismatch: cfa1=-4-40 cfa2=7+8 Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/43e7aae9a7a7710cd6df597fa9dc501da4ba0602.1502472193.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Track DRAP separately from callee-saved registersJosh Poimboeuf2017-08-112-25/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When GCC realigns a function's stack, it sometimes uses %r13 as the DRAP register, like: push %r13 lea 0x10(%rsp), %r13 and $0xfffffffffffffff0, %rsp pushq -0x8(%r13) push %rbp mov %rsp, %rbp push %r13 ... mov -0x8(%rbp),%r13 leaveq lea -0x10(%r13), %rsp pop %r13 retq Since %r13 was pushed onto the stack twice, its two stack locations need to be stored separately. The first push of %r13 is its original value, and the second push of %r13 is the caller's stack frame address. Since %r13 is a callee-saved register, we need to track the stack location of its original value separately from the DRAP register. This fixes the following false positive warning: lib/ubsan.o: warning: objtool: val_to_string.constprop.7()+0x97: leave instruction with modified stack frame Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: baa41469a7b9 ("objtool: Implement stack validation 2.0") Link: http://lkml.kernel.org/r/3da23a6d4c5b3c1e21fc2ccc21a73941b97ff20a.1502401017.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Fix validate_branch() return codesJosh Poimboeuf2017-08-111-3/+3
| | | | | | | | | | | | | | | | | | | | The validate_branch() function should never return a negative value. Errors are treated as warnings so that even if something goes wrong, objtool does its best to generate ORC data for the rest of the file. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: baa41469a7b9 ("objtool: Implement stack validation 2.0") Link: http://lkml.kernel.org/r/d86671cfde823b50477cd2f6f548dfe54871e24d.1502401017.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Disable GCC '-Wpacked' warningsJosh Poimboeuf2017-07-281-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | Objtool is failing to build with GCC 4.4.7 due to the following warnings: cc1: warnings being treated as errors In file included from orc.h:21, from orc_gen.c:21: orc_types.h:86: error: packed attribute is unnecessary for ‘sp_offset’ orc_types.h:87: error: packed attribute is unnecessary for ‘bp_offset’ orc_types.h:88: error: packed attribute is unnecessary for ‘sp_reg’ I suspect those warnings are a GCC bug. But -Wpacked isn't very useful anyway, so just disable it. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 627fce14809b ("objtool: Add ORC unwind table generation") Link: http://lkml.kernel.org/r/76d85d7b5a87566465095c500bce222ff5d7b146.1501188854.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Fix '-mtune=atom' decoding support in objtool 2.0Josh Poimboeuf2017-07-281-1/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With '-mtune=atom', which is enabled with CONFIG_MATOM=y, GCC uses some unusual instructions for setting up the stack. Instead of: mov %rsp, %rbp it does: lea (%rsp), %rbp And instead of: add imm, %rsp it does: lea disp(%rsp), %rsp Add support for these instructions to the objtool decoder. Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: baa41469a7b9 ("objtool: Implement stack validation 2.0") Link: http://lkml.kernel.org/r/4ea1db896e821226efe1f8e09f270771bde47e65.1501188854.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Skip unreachable warnings for 'alt' instructionsJosh Poimboeuf2017-07-281-1/+6
| | | | | | | | | | | | | | | | | | | When a whitelisted function uses one of the ALTERNATIVE macros, it produces false positive warnings like: arch/x86/kvm/vmx.o: warning: objtool: .altinstr_replacement+0x0: unreachable instruction arch/x86/kvm/svm.o: warning: objtool: .altinstr_replacement+0x6e: unreachable instruction There's no easy way to whitelist alternative instructions, so instead just skip any 'unreachable' warnings associated with them. Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/a5d0a8c60155f03b36a31fac871e12cf75f35fd0.1501188854.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Assume unannotated UD2 instructions are dead endsJosh Poimboeuf2017-07-283-9/+70
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Arnd reported some false positive warnings with GCC 7: drivers/hid/wacom_wac.o: warning: objtool: wacom_bpt3_touch()+0x2a5: stack state mismatch: cfa1=7+8 cfa2=6+16 drivers/iio/adc/vf610_adc.o: warning: objtool: vf610_adc_calculate_rates() falls through to next function vf610_adc_sample_set() drivers/pwm/pwm-hibvt.o: warning: objtool: hibvt_pwm_get_state() falls through to next function hibvt_pwm_remove() drivers/pwm/pwm-mediatek.o: warning: objtool: mtk_pwm_config() falls through to next function mtk_pwm_enable() drivers/spi/spi-bcm2835.o: warning: objtool: .text: unexpected end of section drivers/spi/spi-bcm2835aux.o: warning: objtool: .text: unexpected end of section drivers/watchdog/digicolor_wdt.o: warning: objtool: dc_wdt_get_timeleft() falls through to next function dc_wdt_restart() When GCC 7 detects a potential divide-by-zero condition, it sometimes inserts a UD2 instruction for the case where the divisor is zero, instead of letting the hardware trap on the divide instruction. Objtool doesn't consider UD2 to be fatal unless it's annotated with unreachable(). So it considers the GCC-generated UD2 to be non-fatal, and it tries to follow the control flow past the UD2 and gets confused. Previously, objtool *did* assume UD2 was always a dead end. That changed with the following commit: d1091c7fa3d5 ("objtool: Improve detection of BUG() and other dead ends") The motivation behind that change was that Peter was planning on using UD2 for __WARN(), which is *not* a dead end. However, it turns out that some emulators rely on UD2 being fatal, so he ended up using 'ud0' instead: 9a93848fe787 ("x86/debug: Implement __WARN() using UD0") For GCC 4.5+, it should be safe to go back to the previous assumption that UD2 is fatal, even when it's not annotated with unreachable(). But for pre-4.5 versions of GCC, the unreachable() macro isn't supported, so such cases of UD2 need to be explicitly annotated as reachable. Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: d1091c7fa3d5 ("objtool: Improve detection of BUG() and other dead ends") Link: http://lkml.kernel.org/r/e57fa9dfede25f79487da8126ee9cdf7b856db65.1501188854.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Fix gcov check for older versions of GCCJosh Poimboeuf2017-07-254-35/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Objtool tries to silence 'unreachable instruction' warnings when it detects gcov is enabled, because gcov produces a lot of unreachable instructions and they don't really matter. However, the 0-day bot is still reporting some unreachable instruction warnings with CONFIG_GCOV_KERNEL=y on GCC 4.6.4. As it turns out, objtool's gcov detection doesn't work with older versions of GCC because they don't create a bunch of symbols with the 'gcov.' prefix like newer versions of GCC do. Move the gcov check out of objtool and instead just create a new '--no-unreachable' flag which can be passed in by the kernel Makefile when CONFIG_GCOV_KERNEL is defined. Also rename the 'nofp' variable to 'no_fp' for consistency with the new 'no_unreachable' variable. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 9cfffb116887 ("objtool: Skip all "unreachable instruction" warnings for gcov kernels") Link: http://lkml.kernel.org/r/c243dc78eb2ffdabb6e927844dea39b6033cd395.1500939244.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool, x86: Add facility for asm code to provide unwind hintsJosh Poimboeuf2017-07-184-13/+207
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Some asm (and inline asm) code does special things to the stack which objtool can't understand. (Nor can GCC or GNU assembler, for that matter.) In such cases we need a facility for the code to provide annotations, so the unwinder can unwind through it. This provides such a facility, in the form of unwind hints. They're similar to the GNU assembler .cfi* directives, but they give more information, and are needed in far fewer places, because objtool can fill in the blanks by following branches and adjusting the stack pointer for pushes and pops. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/0f5f3c9104fca559ff4088bece1d14ae3bca52d5.1499786555.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Add ORC unwind table generationJosh Poimboeuf2017-07-1814-60/+916
| | | | | | | | | | | | | | | | | | | | | | | | | | Now that objtool knows the states of all registers on the stack for each instruction, it's straightforward to generate debuginfo for an unwinder to use. Instead of generating DWARF, generate a new format called ORC, which is more suitable for an in-kernel unwinder. See Documentation/x86/orc-unwinder.txt for a more detailed description of this new debuginfo format and why it's preferable to DWARF. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/c9b9f01ba6c5ed2bdc9bb0957b78167fdbf9632e.1499786555.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Fix sibling call detection logicJosh Poimboeuf2017-07-081-2/+11
| | | | | | | | | | | | | | | | | | | | | | | | | With some configs, objtool reports the following warning: arch/x86/kernel/ftrace.o: warning: objtool: ftrace_modify_code_direct()+0x2d: sibling call from callable instruction with modified stack frame The instruction it's complaining about isn't actually a sibling call. It's just a normal jump to an address inside the function. Objtool thought it was a sibling call because the instruction's jump_dest wasn't initialized because the function was supposed to be ignored due to its use of sync_core(). Objtool ended up validating the function instead of ignoring it because it didn't properly recognize a sibling call to the function. So fix the sibling call logic. Also add a warning to catch ignored functions being validated so we'll get a more useful error message next time. Reported-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/96cc8ecbcdd8cb29ddd783817b4af918a6a171b0.1499437107.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Merge branch 'perf-core-for-linus' of ↵Linus Torvalds2017-07-031-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf updates from Ingo Molnar: "Most of the changes are for tooling, the main changes in this cycle were: - Improve Intel-PT hardware tracing support, both on the kernel and on the tooling side: PTWRITE instruction support, power events for C-state tracing, etc. (Adrian Hunter) - Add support to measure SMI cost to the x86 architecture, with tooling support in 'perf stat' (Kan Liang) - Support function filtering in 'perf ftrace', plus related improvements (Namhyung Kim) - Allow adding and removing fields to the default 'perf script' columns, using + or - as field prefixes to do so (Andi Kleen) - Allow resolving the DSO name with 'perf script -F brstack{sym,off},dso' (Mark Santaniello) - Add perf tooling unwind support for PowerPC (Paolo Bonzini) - ... and various other improvements as well" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (84 commits) perf auxtrace: Add CPU filter support perf intel-pt: Do not use TSC packets for calculating CPU cycles to TSC perf intel-pt: Update documentation to include new ptwrite and power events perf intel-pt: Add example script for power events and PTWRITE perf intel-pt: Synthesize new power and "ptwrite" events perf intel-pt: Move code in intel_pt_synth_events() to simplify attr setting perf intel-pt: Factor out intel_pt_set_event_name() perf intel-pt: Tidy messages into called function intel_pt_synth_event() perf intel-pt: Tidy Intel PT evsel lookup into separate function perf intel-pt: Join needlessly wrapped lines perf intel-pt: Remove unused instructions_sample_period perf intel-pt: Factor out common code synthesizing event samples perf script: Add synthesized Intel PT power and ptwrite events perf/x86/intel: Constify the 'lbr_desc[]' array and make a function static perf script: Add 'synth' field for synthesized event payloads perf auxtrace: Add itrace option to output power events perf auxtrace: Add itrace option to output ptwrite events tools include: Add byte-swapping macros to kernel.h perf script: Add 'synth' event type for synthesized events x86/insn: perf tools: Add new ptwrite instruction ...
| * x86/insn: perf tools: Add new ptwrite instructionAdrian Hunter2017-06-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add ptwrite to the op code map and the perf tools new instructions test. To run the test: $ tools/perf/perf test "x86 ins" 39: Test x86 instruction decoder - new instructions : Ok Or to see the details: $ tools/perf/perf test -v "x86 ins" 2>&1 | grep ptwrite For information about ptwrite, refer the Intel SDM. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Link: http://lkml.kernel.org/r/1495180230-19367-1-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* | objtool: Silence warnings for functions which use IRETJosh Poimboeuf2017-06-301-8/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously, objtool ignored functions which have the IRET instruction in them. That's because it assumed that such functions know what they're doing with respect to frame pointers. With the new "objtool 2.0" changes, it stopped ignoring such functions, and started complaining about them: arch/x86/kernel/alternative.o: warning: objtool: do_sync_core()+0x1b: unsupported instruction in callable function arch/x86/kernel/alternative.o: warning: objtool: text_poke()+0x1a8: unsupported instruction in callable function arch/x86/kernel/ftrace.o: warning: objtool: do_sync_core()+0x16: unsupported instruction in callable function arch/x86/kernel/cpu/mcheck/mce.o: warning: objtool: machine_check_poll()+0x166: unsupported instruction in callable function arch/x86/kernel/cpu/mcheck/mce.o: warning: objtool: do_machine_check()+0x147: unsupported instruction in callable function Silence those warnings for now. They can be re-enabled later, once we have unwind hints which will allow the code to annotate the IRET usages. Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: live-patching@vger.kernel.org Fixes: baa41469a7b9 ("objtool: Implement stack validation 2.0") Link: http://lkml.kernel.org/r/20170630140934.mmwtpockvpupahro@treble Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | objtool: Implement stack validation 2.0Josh Poimboeuf2017-06-3011-320/+1130
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is a major rewrite of objtool. Instead of only tracking frame pointer changes, it now tracks all stack-related operations, including all register saves/restores. In addition to making stack validation more robust, this also paves the way for undwarf generation. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/678bd94c0566c6129bcc376cddb259c4c5633004.1498659915.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | objtool: Move checking code to check.cJosh Poimboeuf2017-06-304-1268/+1328
|/ | | | | | | | | | | | | | | | In preparation for the new 'objtool undwarf generate' command, which will rely on 'objtool check', move the checking code from builtin-check.c to check.c where it can be used by other commands. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Reviewed-by: Jiri Slaby <jslaby@suse.cz> Cc: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/294c5c695fd73c1a5000bbe5960a7c9bec4ee6b4.1498659915.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Add fortify_panic as __noreturn functionKees Cook2017-06-161-1/+2
| | | | | | | | | | | | | | | CONFIG_FORTIFY_SOURCE=y implements fortify_panic() as a __noreturn function, so objtool needs to know about it too. Suggested-by: Daniel Micay <danielmicay@gmail.com> Tested-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1497532835-32704-1-git-send-email-jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Drop ARRAY_SIZE() definition, tools/include/linux/kernel.h has it nowArnaldo Carvalho de Melo2017-04-192-4/+2
| | | | | | | | | | | | | | And with the goodies present in the kernel.h counterpart, i.e. checking that the parameter is an array at build time. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-roiwxwgwgld4kygn65if60wa@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* objtool: Fix another GCC jump table detection issueJosh Poimboeuf2017-03-073-3/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Arnd Bergmann reported a (false positive) objtool warning: drivers/infiniband/sw/rxe/rxe_resp.o: warning: objtool: rxe_responder()+0xfe: sibling call from callable instruction with changed frame pointer The issue is in find_switch_table(). It tries to find a switch statement's jump table by walking backwards from an indirect jump instruction, looking for a relocation to the .rodata section. In this case it stopped walking prematurely: the first .rodata relocation it encountered was for a variable (resp_state_name) instead of a jump table, so it just assumed there wasn't a jump table. The fix is to ignore any .rodata relocation which refers to an ELF object symbol. This works because the jump tables are anonymous and have no symbols associated with them. Reported-by: Arnd Bergmann <arnd@arndb.de> Tested-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 3732710ff6f2 ("objtool: Improve rare switch jump table pattern detection") Link: http://lkml.kernel.org/r/20170302225723.3ndbsnl4hkqbne7a@treble Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool, modules: Discard objtool annotation sections for modulesJosh Poimboeuf2017-03-011-3/+3
| | | | | | | | | | | | | | | | | | | | | | The '__unreachable' and '__func_stack_frame_non_standard' sections are only used at compile time. They're discarded for vmlinux but they should also be discarded for modules. Since this is a recurring pattern, prefix the section names with ".discard.". It's a nice convention and vmlinux.lds.h already discards such sections. Also remove the 'a' (allocatable) flag from the __unreachable section since it doesn't make sense for a discarded section. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Jessica Yu <jeyu@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: d1091c7fa3d5 ("objtool: Improve detection of BUG() and other dead ends") Link: http://lkml.kernel.org/r/20170301180444.lhd53c5tibc4ns77@treble Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Improve detection of BUG() and other dead endsJosh Poimboeuf2017-02-243-10/+58
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The BUG() macro's use of __builtin_unreachable() via the unreachable() macro tells gcc that the instruction is a dead end, and that it's safe to assume the current code path will not execute past the previous instruction. On x86, the BUG() macro is implemented with the 'ud2' instruction. When objtool's branch analysis sees that instruction, it knows the current code path has come to a dead end. Peter Zijlstra has been working on a patch to change the WARN macros to use 'ud2'. That patch will break objtool's assumption that 'ud2' is always a dead end. Generally it's best for objtool to avoid making those kinds of assumptions anyway. The more ignorant it is of kernel code internals, the better. So create a more generic way for objtool to detect dead ends by adding an annotation to the unreachable() macro. The annotation stores a pointer to the end of the unreachable code path in an '__unreachable' section. Objtool can read that section to find the dead ends. Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/41a6d33971462ebd944a1c60ad4bf5be86c17b77.1487712920.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Fix IRET's opcodeJiri Slaby2017-01-191-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | The IRET opcode is 0xcf according to the Intel manual and also to objdump of my vmlinux: 1ea8: 48 cf iretq Fix the opcode in arch_decode_instruction(). The previous value (0xc5) seems to correspond to LDS. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170118132921.19319-1-jslaby@suse.cz Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Merge branch 'kbuild' of ↵Linus Torvalds2016-12-181-2/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild Pull kbuild updates from Michal Marek: - prototypes for x86 asm-exported symbols (Adam Borowski) and a warning about missing CRCs (Nick Piggin) - asm-exports fix for LTO (Nicolas Pitre) - thin archives improvements (Nick Piggin) - linker script fix for CONFIG_LD_DEAD_CODE_DATA_ELIMINATION (Nick Piggin) - genksyms support for __builtin_va_list keyword - misc minor fixes * 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: x86/kbuild: enable modversions for symbols exported from asm kbuild: fix scripts/adjust_autoksyms.sh* for the no modules case scripts/kallsyms: remove last remnants of --page-offset option make use of make variable CURDIR instead of calling pwd kbuild: cmd_export_list: tighten the sed script kbuild: minor improvement for thin archives build kbuild: modpost warn if export version crc is missing kbuild: keep data tables through dead code elimination kbuild: improve linker compatibility with lib-ksyms.o build genksyms: Regenerate parser kbuild/genksyms: handle va_list type kbuild: thin archives for multi-y targets kbuild: kallsyms allow 3-pass generation if symbols size has changed
| * make use of make variable CURDIR instead of calling pwdUwe Kleine-König2016-12-111-2/+2
| | | | | | | | | | | | | | | | | | | | make already provides the current working directory in a variable, so make use of it instead of forking a shell. Also replace usage of PWD by CURDIR. PWD is provided by most shells, but not all, so this makes the build system more robust. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Michal Marek <mmarek@suse.com>
* | objtool: Fix bytes check of lea's rex_prefixJiri Slaby2016-12-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For the "lea %(rsp), %rbp" case, we check if there is a rex_prefix. But we check 'bytes' which is insn_byte_t[4] in rex_prefix (insn_field structure). Therefore, the check is always true. Instead, check 'nbytes' which is the right one. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20161205105551.25917-1-jslaby@suse.cz Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | objtool: Fix rare switch jump table pattern detectionJosh Poimboeuf2016-10-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following commit: 3732710ff6f2 ("objtool: Improve rare switch jump table pattern detection") ... improved objtool's ability to detect GCC switch statement jump tables for GCC 6. However the check to allow short jumps with the scanned range of instructions wasn't quite right. The pattern detection should allow jumps to the indirect jump instruction itself. This fixes the following warning: drivers/infiniband/sw/rxe/rxe_comp.o: warning: objtool: rxe_completer()+0x315: sibling call from callable instruction with changed frame pointer Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 3732710ff6f2 ("objtool: Improve rare switch jump table pattern detection") Link: http://lkml.kernel.org/r/20161026153408.2rifnw7bvoc5sex7@treble Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | objtool: Skip all "unreachable instruction" warnings for gcov kernelsJosh Poimboeuf2016-10-161-31/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Recently objtool has started reporting a few "unreachable instruction" warnings when CONFIG_GCOV is enabled for newer versions of GCC. Usually this warning means there's some new control flow that objtool doesn't understand. But in this case, objtool is correct and the instructions really are inaccessible. It's an annoying quirk of gcov, but it's harmless, so it's ok to just silence the warnings. With older versions of GCC, it was relatively easy to detect gcov-specific instructions and to skip any unreachable warnings produced by them. But GCC 6 has gotten craftier. Instead of continuing to play whack-a-mole with gcov, just use a bigger, more permanent hammer and disable unreachable warnings for the whole file when gcov is enabled. This is fine to do because a) unreachable warnings are usually of questionable value; and b) gcov isn't used for production kernels and we can relax the checks a bit there. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/38d5c87d61d9cd46486dd2c86f46603dff0df86f.1476393584.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | objtool: Improve rare switch jump table pattern detectionJosh Poimboeuf2016-10-161-2/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | GCC 6 added a new switch statement jump table optimization which makes objtool's life harder. It looks like: mov [rodata addr],%reg1 ... some instructions ... jmpq *(%reg1,%reg2,8) The optimization is quite rare, but objtool still needs to be able to identify the pattern so that it can follow all possible control flow paths related to the switch statement. In order to detect the pattern, objtool starts from the indirect jump and scans backwards through the function until it finds the first instruction in the pattern. If it encounters an unconditional jump along the way, it stops and considers the pattern to be not found. As it turns out, unconditional jumps can happen, as long as they are small forward jumps within the range being scanned. This fixes the following warnings: drivers/infiniband/sw/rxe/rxe_comp.o: warning: objtool: rxe_completer()+0x2f4: sibling call from callable instruction with changed frame pointer drivers/infiniband/sw/rxe/rxe_resp.o: warning: objtool: rxe_responder()+0x10f: sibling call from callable instruction with changed frame pointer Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/8a9ed68ae1780e8d3963e4ee13f2f257fe3a3c33.1476393584.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | objtool: Support '-mtune=atom' stack frame setup instructionJosh Poimboeuf2016-10-111-0/+9
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Arnd reported that enabling CONFIG_MATOM results in a bunch of objtool false positive frame pointer warnings: arch/x86/events/intel/ds.o: warning: objtool: intel_pmu_pebs_del()+0x43: call without frame pointer save/setup security/keys/keyring.o: warning: objtool: keyring_read()+0x59: call without frame pointer save/setup kernel/signal.o: warning: objtool: __dequeue_signal()+0xd8: call without frame pointer save/setup ... objtool gets confused by the fact that the '-mtune=atom' GCC option sometimes uses 'lea (%rsp),%rbp' instead of 'mov %rsp,%rbp'. The instructions are effectively the same, but objtool doesn't know about the 'lea' variant. Fix the false warnings by adding support for 'lea (%rsp),%rbp' in the objtool decoder. Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* objtool: Add do_task_dead() to global noreturn listJosh Poimboeuf2016-09-231-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | objtool reports the following new warning: kernel/exit.o: warning: objtool: do_exit() falls through to next function complete_and_exit() The warning is caused by do_exit()'s new call to do_task_dead(), which is a new "noreturn" function which objtool doesn't know about yet, introduced by: 9af6528ee9b6 ("sched/core: Optimize __schedule()") ( objtool has to know all the global noreturn functions so it can follow the control flow of any functions which call them. Unfortunately they need to be hard-coded because there's no automated way to detect them. ) Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kbuild-all@01.org Cc: tipbuild@zytor.com Link: http://lkml.kernel.org/r/20160922212125.zbuewckqll4yur25@treble Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Merge branch 'core-urgent-for-linus' of ↵Linus Torvalds2016-07-308-154/+310
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull misc fixes from Thomas Gleixner: "This update contains: - a fix for stomp-machine so the nmi_watchdog wont trigger on the cpu waiting for the others to execute the callback - various fixes and updates to objtool including an resync of the instruction decoder to match the kernel's decoder" * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: objtool: Un-capitalize "Warning" for out-of-sync instruction decoder objtool: Resync x86 instruction decoder with the kernel's objtool: Support new GCC 6 switch jump table pattern stop_machine: Touch_nmi_watchdog() after MULTI_STOP_PREPARE objtool: Add 'fixdep' to objtool/.gitignore
| * objtool: Un-capitalize "Warning" for out-of-sync instruction decoderJosh Poimboeuf2016-07-291-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change "Warning" to "warning" to make it look more like a GCC warning. Hopefully that will be enough to help the 0-day bot or other automated tools catch this warning earlier before it ends up in Linus's tree. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/b1669f391a5db91040427fd9f8e1e79db18f9709.1469751119.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * objtool: Resync x86 instruction decoder with the kernel'sJosh Poimboeuf2016-07-295-101/+220
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This fixes the following warning: Warning: objtool: x86 instruction decoder differs from kernel Unfortunately we have three identical copies of the x86 instruction decoder in the kernel tree that have to be manually kept in sync. It's on my TODO list to at least library-ize the ones in the tools subdir so we'd only have two of them instead of three. In the meantime, here's another manual sync. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: c61f4d5ebaf0 ("perf tools: Add AVX-512 support to the instruction decoder used by Intel PT") Link: http://lkml.kernel.org/r/d7f74b4d91fed25b0be33cd5c86f5131fa1a7529.1469751119.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-12 18:24:09 +0100