1. 20 4月, 2016 3 次提交
  2. 30 3月, 2016 5 次提交
    • N
      kbuild: create/adjust generated/autoksyms.h · 23121ca2
      Nicolas Pitre 提交于
      Given the list of exported symbols needed by all modules, we can create
      a header file containing preprocessor defines for each of those symbols.
      Also, when some symbols are added and/or removed from the list, we can
      update the time on the corresponding files used as build dependencies for
      those symbols. And finally, if any symbol did change state, the
      corresponding source files must be rebuilt.
      
      The insertion or removal of an EXPORT_SYMBOL() entry within a module may
      create or remove the need for another exported symbol.  This is why this
      operation has to be repeated until the list of needed exported symbols
      becomes stable. Only then the final kernel and modules link take place.
      Signed-off-by: NNicolas Pitre <nico@linaro.org>
      Acked-by: NRusty Russell <rusty@rustcorp.com.au>
      23121ca2
    • N
      kbuild: add fine grained build dependencies for exported symbols · c1a95fda
      Nicolas Pitre 提交于
      Like with kconfig options, we now have the ability to compile in and
      out individual EXPORT_SYMBOL() declarations based on the content of
      include/generated/autoksyms.h.  However we don't want the entire
      world to be rebuilt whenever that file is touched.
      
      Let's apply the same build dependency trick used for CONFIG_* symbols
      where the time stamp of empty files whose paths matching those symbols
      is used to trigger fine grained rebuilds. In our case the key is the
      symbol name passed to EXPORT_SYMBOL().
      
      However, unlike config options, we cannot just use fixdep to parse
      the source code for EXPORT_SYMBOL(ksym) because several variants exist
      and parsing them all in a separate tool, and keeping it in synch, is
      not trivially maintainable.  Furthermore, there are variants such as
      
      	EXPORT_SYMBOL_GPL(pci_user_read_config_##size);
      
      that are instanciated via a macro for which we can't easily determine
      the actual exported symbol name(s) short of actually running the
      preprocessor on them.
      
      Storing the symbol name string in a special ELF section doesn't work
      for targets that output assembly or preprocessed source.
      
      So the best way is really to leverage the preprocessor by having it
      output actual symbol names anchored by a special sequence that can be
      easily filtered out. Then the list of symbols is simply fed to fixdep
      to be merged with the other dependencies.
      
      That implies the preprocessor is executed twice for each source file.
      A previous attempt relied on a warning pragma for each EXPORT_SYMBOL()
      instance that was filtered apart from stderr by the build system with
      a sed script during the actual compilation pass. Unfortunately the
      preprocessor/compiler diagnostic output isn't stable between versions
      and this solution, although more efficient, was deemed too fragile.
      
      Because of the lowercasing performed by fixdep, there might be name
      collisions triggering spurious rebuilds for similar symbols. But this
      shouldn't be a big issue in practice. (This is the case for CONFIG_*
      symbols and I didn't want to be different here, whatever the original
      reason for doing so.)
      
      To avoid needless build overhead, the exported symbol name gathering is
      performed only when CONFIG_TRIM_UNUSED_KSYMS is selected.
      Signed-off-by: NNicolas Pitre <nico@linaro.org>
      Acked-by: NRusty Russell <rusty@rustcorp.com.au>
      c1a95fda
    • N
      kbuild: de-duplicate fixdep usage · e4aca459
      Nicolas Pitre 提交于
      The generation and postprocessing of automatic dependency rules is
      duplicated in rule_cc_o_c, rule_as_o_S and if_changed_dep. Since
      this is not a trivial one-liner action, it is now abstracted under
      cmd_and_fixdep to simplify things and make future changes in this area
      easier.
      
      In the rule_cc_o_c and rule_as_o_S cases that means the order of some
      commands has been altered, namely fixdep and related file manipulations
      are executed earlier, but they didn't depend on those commands that now
      execute later.
      Signed-off-by: NNicolas Pitre <nico@linaro.org>
      e4aca459
    • N
      fixdep: accept extra dependencies on stdin · d8329e35
      Nicolas Pitre 提交于
      ... and merge them in the list of parsed dependencies.
      Signed-off-by: NNicolas Pitre <nico@linaro.org>
      d8329e35
    • N
      kbuild: record needed exported symbols for modules · 9895c03d
      Nicolas Pitre 提交于
      Kernel modules are partially linked object files with some undefined
      symbols that are expected to be matched with EXPORT_SYMBOL() entries
      from elsewhere.
      
      Each .tmp_versions/*.mod file currently contains two line of text
      separated by a newline character. The first line has the actual module
      file name while the second line has a list of object files constituting
      that module. Those files are parsed by modpost (scripts/mod/sumversion.c),
      scripts/Makefile.modpost, scripts/Makefile.modsign, etc.  Only the
      modpost utility cares about the second line while the others retrieve
      only the first line.
      
      Therefore we can add a third line to record the list of undefined symbols
      aka required EXPORT_SYMBOL() entries for each module into that file
      without breaking anything. Like for the second line, symbols are separated
      by a blank and the list is terminated with a newline character.
      
      To avoid needless build overhead, the undefined symbols extraction is
      performed only when CONFIG_TRIM_UNUSED_KSYMS is selected.
      Signed-off-by: NNicolas Pitre <nico@linaro.org>
      Acked-by: NRusty Russell <rusty@rustcorp.com.au>
      9895c03d
  3. 23 3月, 2016 6 次提交
    • H
      parisc: Use generic extable search and sort routines · 0de79858
      Helge Deller 提交于
      Switch to the generic extable search and sort routines which were introduced
      with commit a272858a from Ard Biesheuvel. This saves quite some memory in the
      vmlinux binary with the 64bit kernel.
      Signed-off-by: NHelge Deller <deller@gmx.de>
      0de79858
    • A
      ubsan: fix tree-wide -Wmaybe-uninitialized false positives · dde5cf39
      Andrey Ryabinin 提交于
      -fsanitize=* options makes GCC less smart than usual and increase number
      of 'maybe-uninitialized' false-positives. So this patch does two things:
      
       * Add -Wno-maybe-uninitialized to CFLAGS_UBSAN which will disable all
         such warnings for instrumented files.
      
       * Remove CONFIG_UBSAN_SANITIZE_ALL from all[yes|mod]config builds. So
         the all[yes|mod]config build goes without -fsanitize=* and still with
         -Wmaybe-uninitialized.
      Signed-off-by: NAndrey Ryabinin <aryabinin@virtuozzo.com>
      Reported-by: NFengguang Wu <fengguang.wu@intel.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      dde5cf39
    • J
      scripts/gdb: account for changes in module data structure · ad4db3b2
      Jan Kiszka 提交于
      Commit 7523e4dc ("module: use a structure to encapsulate layout.")
      factored out the module_layout structure.  Adjust the symbol loader and
      the lsmod command to this.
      Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
      Reviewed-by: NKieran Bingham <kieran.bingham@linaro.org>
      Tested-by: Kieran Bingham <kieran.bingham@linaro.org> (qemu-{ARM,x86})
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Jiri Kosina <jkosina@suse.cz>
      Cc: Jason Wessel <jason.wessel@windriver.com>
      Cc: <stable@vger.kernel.org>	[4.4+]
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      ad4db3b2
    • K
      scripts/gdb: add cmdline reader command · 72bf92ec
      Kieran Bingham 提交于
      lx-cmdline Report the Linux Commandline used in the current kernel
      
      [jan.kiszka@siemens.com: remove blank line from help output and fix pep8 warning]
      Signed-off-by: NKieran Bingham <kieran.bingham@linaro.org>
      Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
      Cc: Jason Wessel <jason.wessel@windriver.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      72bf92ec
    • K
      scripts/gdb: add version command · 2d061d99
      Kieran Bingham 提交于
      lx-version Report the Linux Version of the current kernel.
      
      Add a command to identify the version specified by the banner in the
      debugged kernel.
      
      This lets the user identify the kernel of the running kernel, and will
      let later scripts compare the banner of the attached kernel against the
      banner in the vmlinux symbols files to verify that the files are
      correct.
      
      [jan.kiszka@siemens.com: remove blank line from help output and fix pep8 warning]
      Signed-off-by: NKieran Bingham <kieran.bingham@linaro.org>
      Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
      Cc: Jason Wessel <jason.wessel@windriver.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      2d061d99
    • D
      kernel: add kcov code coverage · 5c9a8750
      Dmitry Vyukov 提交于
      kcov provides code coverage collection for coverage-guided fuzzing
      (randomized testing).  Coverage-guided fuzzing is a testing technique
      that uses coverage feedback to determine new interesting inputs to a
      system.  A notable user-space example is AFL
      (http://lcamtuf.coredump.cx/afl/).  However, this technique is not
      widely used for kernel testing due to missing compiler and kernel
      support.
      
      kcov does not aim to collect as much coverage as possible.  It aims to
      collect more or less stable coverage that is function of syscall inputs.
      To achieve this goal it does not collect coverage in soft/hard
      interrupts and instrumentation of some inherently non-deterministic or
      non-interesting parts of kernel is disbled (e.g.  scheduler, locking).
      
      Currently there is a single coverage collection mode (tracing), but the
      API anticipates additional collection modes.  Initially I also
      implemented a second mode which exposes coverage in a fixed-size hash
      table of counters (what Quentin used in his original patch).  I've
      dropped the second mode for simplicity.
      
      This patch adds the necessary support on kernel side.  The complimentary
      compiler support was added in gcc revision 231296.
      
      We've used this support to build syzkaller system call fuzzer, which has
      found 90 kernel bugs in just 2 months:
      
        https://github.com/google/syzkaller/wiki/Found-Bugs
      
      We've also found 30+ bugs in our internal systems with syzkaller.
      Another (yet unexplored) direction where kcov coverage would greatly
      help is more traditional "blob mutation".  For example, mounting a
      random blob as a filesystem, or receiving a random blob over wire.
      
      Why not gcov.  Typical fuzzing loop looks as follows: (1) reset
      coverage, (2) execute a bit of code, (3) collect coverage, repeat.  A
      typical coverage can be just a dozen of basic blocks (e.g.  an invalid
      input).  In such context gcov becomes prohibitively expensive as
      reset/collect coverage steps depend on total number of basic
      blocks/edges in program (in case of kernel it is about 2M).  Cost of
      kcov depends only on number of executed basic blocks/edges.  On top of
      that, kernel requires per-thread coverage because there are always
      background threads and unrelated processes that also produce coverage.
      With inlined gcov instrumentation per-thread coverage is not possible.
      
      kcov exposes kernel PCs and control flow to user-space which is
      insecure.  But debugfs should not be mapped as user accessible.
      
      Based on a patch by Quentin Casasnovas.
      
      [akpm@linux-foundation.org: make task_struct.kcov_mode have type `enum kcov_mode']
      [akpm@linux-foundation.org: unbreak allmodconfig]
      [akpm@linux-foundation.org: follow x86 Makefile layout standards]
      Signed-off-by: NDmitry Vyukov <dvyukov@google.com>
      Reviewed-by: NKees Cook <keescook@chromium.org>
      Cc: syzkaller <syzkaller@googlegroups.com>
      Cc: Vegard Nossum <vegard.nossum@oracle.com>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Tavis Ormandy <taviso@google.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
      Cc: Kostya Serebryany <kcc@google.com>
      Cc: Eric Dumazet <edumazet@google.com>
      Cc: Alexander Potapenko <glider@google.com>
      Cc: Kees Cook <keescook@google.com>
      Cc: Bjorn Helgaas <bhelgaas@google.com>
      Cc: Sasha Levin <sasha.levin@oracle.com>
      Cc: David Drysdale <drysdale@google.com>
      Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
      Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
      Cc: Kirill A. Shutemov <kirill@shutemov.name>
      Cc: Jiri Slaby <jslaby@suse.cz>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      5c9a8750
  4. 16 3月, 2016 7 次提交
  5. 13 3月, 2016 1 次提交
  6. 05 3月, 2016 3 次提交
    • J
      objtool: Detect and warn if libelf is missing and don't break the build · 3b27a0c8
      Josh Poimboeuf 提交于
      With CONFIG_STACK_VALIDATION enabled, if the host system doesn't have
      a development version of libelf installed, the build fails with errors
      like:
      
        elf.h:22:18: fatal error: gelf.h: No such file or directory compilation terminated.
      
      Instead of failing to build, instead just print a warning and disable
      stack validation.
      Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Stephen Rothwell <sfr@canb.auug.org.au>
      Cc: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: linux-next@vger.kernel.org
      Cc: linux@roeck-us.net
      Cc: live-patching@vger.kernel.org
      Link: http://lkml.kernel.org/r/8c27fe00face60f42e888ddb3142c97e45223165.1457026550.git.jpoimboe@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      3b27a0c8
    • M
      kbuild: suppress annoying "... is up to date." message · 2aedcd09
      Masahiro Yamada 提交于
      Under certain conditions, Kbuild shows "... is up to date" where
      if_changed or friends are used.
      
      For example, the incremental build of ARM64 Linux shows this message
      when the kernel image has not been updated.
      
        $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu-
          CHK     include/config/kernel.release
          CHK     include/generated/uapi/linux/version.h
          CHK     include/generated/utsrelease.h
          CHK     include/generated/bounds.h
          CHK     include/generated/timeconst.h
          CHK     include/generated/asm-offsets.h
          CALL    scripts/checksyscalls.sh
          CHK     include/generated/compile.h
          CHK     kernel/config_data.h
        make[1]: `arch/arm64/boot/Image.gz' is up to date.
          Building modules, stage 2.
          MODPOST 0 modules
      
      The following is the build rule in arch/arm64/boot/Makefile:
      
        $(obj)/Image.gz: $(obj)/Image FORCE
                $(call if_changed,gzip)
      
      If the Image.gz is newer than the Image and the command line has not
      changed (i.e., $(any-prereq) and $(arg-check) are both empty), the
      build rule $(call if_changed,gzip) is evaluated to be empty, then
      GNU Make reports the target is up to date.  In order to make GNU Make
      quiet, we need to give it something to do, for example, "@:".  This
      should be fixed in the Kbuild core part rather than in each Makefile.
      Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
      Signed-off-by: NMichal Marek <mmarek@suse.com>
      2aedcd09
    • P
      kbuild/mkspec: clean boot loader configuration on rpm removal · 6ef41e22
      Paolo Abeni 提交于
      This patch add a rpm preuninstall scriptlet to cleanup the
      boot loader configuration on kernel package uninstall.
      The initrd for the to-be-removed kernel is deleted, too.
      Signed-off-by: NPaolo Abeni <pabeni@redhat.com>
      Signed-off-by: NMichal Marek <mmarek@suse.com>
      6ef41e22
  7. 03 3月, 2016 1 次提交
  8. 29 2月, 2016 2 次提交
    • J
      objtool: Add CONFIG_STACK_VALIDATION option · b9ab5ebb
      Josh Poimboeuf 提交于
      Add a CONFIG_STACK_VALIDATION option which will run "objtool check" for
      each .o file to ensure the validity of its stack metadata.
      Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
      Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Chris J Arges <chris.j.arges@canonical.com>
      Cc: Jiri Slaby <jslaby@suse.cz>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Michal Marek <mmarek@suse.cz>
      Cc: Namhyung Kim <namhyung@gmail.com>
      Cc: Pedro Alves <palves@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: live-patching@vger.kernel.org
      Link: http://lkml.kernel.org/r/92baab69a6bf9bc7043af0bfca9fb964a1d45546.1456719558.git.jpoimboe@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      b9ab5ebb
    • J
      objtool: Mark non-standard object files and directories · c0dd6716
      Josh Poimboeuf 提交于
      Code which runs outside the kernel's normal mode of operation often does
      unusual things which can cause a static analysis tool like objtool to
      emit false positive warnings:
      
       - boot image
       - vdso image
       - relocation
       - realmode
       - efi
       - head
       - purgatory
       - modpost
      
      Set OBJECT_FILES_NON_STANDARD for their related files and directories,
      which will tell objtool to skip checking them.  It's ok to skip them
      because they don't affect runtime stack traces.
      
      Also skip the following code which does the right thing with respect to
      frame pointers, but is too "special" to be validated by a tool:
      
       - entry
       - mcount
      
      Also skip the test_nx module because it modifies its exception handling
      table at runtime, which objtool can't understand.  Fortunately it's
      just a test module so it doesn't matter much.
      
      Currently objtool is the only user of OBJECT_FILES_NON_STANDARD, but it
      might eventually be useful for other tools.
      Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
      Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Chris J Arges <chris.j.arges@canonical.com>
      Cc: Jiri Slaby <jslaby@suse.cz>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Michal Marek <mmarek@suse.cz>
      Cc: Namhyung Kim <namhyung@gmail.com>
      Cc: Pedro Alves <palves@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: live-patching@vger.kernel.org
      Link: http://lkml.kernel.org/r/366c080e3844e8a5b6a0327dc7e8c2b90ca3baeb.1456719558.git.jpoimboe@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      c0dd6716
  9. 26 2月, 2016 3 次提交
  10. 24 2月, 2016 4 次提交
    • A
      arm64: switch to relative exception tables · 6c94f27a
      Ard Biesheuvel 提交于
      Instead of using absolute addresses for both the exception location
      and the fixup, use offsets relative to the exception table entry values.
      Not only does this cut the size of the exception table in half, it is
      also a prerequisite for KASLR, since absolute exception table entries
      are subject to dynamic relocation, which is incompatible with the sorting
      of the exception table that occurs at build time.
      
      This patch also introduces the _ASM_EXTABLE preprocessor macro (which
      exists on x86 as well) and its _asm_extable assembly counterpart, as
      shorthands to emit exception table entries.
      Acked-by: NWill Deacon <will.deacon@arm.com>
      Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
      Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
      6c94f27a
    • A
      scripts/sortextable: add support for ET_DYN binaries · 7b957b6e
      Ard Biesheuvel 提交于
      Add support to scripts/sortextable for handling relocatable (PIE)
      executables, whose ELF type is ET_DYN, not ET_EXEC. Other than adding
      support for the new type, no changes are needed.
      Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
      Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
      7b957b6e
    • B
      sparse: Add __private to privatize members of structs · ad315455
      Boqun Feng 提交于
      In C programming language, we don't have a easy way to privatize a
      member of a structure. However in kernel, sometimes there is a need to
      privatize a member in case of potential bugs or misuses.
      
      Fortunately, the noderef attribute of sparse is a way to privatize a
      member, as by defining a member as noderef, the address-of operator on
      the member will produce a noderef pointer to that member, and if anyone
      wants to dereference that kind of pointers to read or modify the member,
      sparse will yell.
      
      Based on this, __private modifier and related operation ACCESS_PRIVATE()
      are introduced, which could help detect undesigned public uses of
      private members of structs. Here is an example of sparse's output if it
      detect an undersigned public use:
      
      | kernel/rcu/tree.c:4453:25: warning: incorrect type in argument 1 (different modifiers)
      | kernel/rcu/tree.c:4453:25:    expected struct raw_spinlock [usertype] *lock
      | kernel/rcu/tree.c:4453:25:    got struct raw_spinlock [noderef] *<noident>
      
      Also, this patch improves compiler.h a little bit by adding comments for
      "#else" and "#endif".
      Signed-off-by: NBoqun Feng <boqun.feng@gmail.com>
      Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      ad315455
    • R
      kbuild: Allow using host dtc instead of kernel's copy · 6b22b3d1
      Rob Herring 提交于
      Development of dtc happens in its own upstream repository, but testing
      dtc changes against the kernel tree is useful. Change dtc to a variable
      that users can override.
      Signed-off-by: NRob Herring <robh@kernel.org>
      Cc: Michal Marek <mmarek@suse.com>
      Cc: linux-kbuild@vger.kernel.org
      6b22b3d1
  11. 19 2月, 2016 5 次提交