user/sven/linux.git/scripts/Makefile.lib, branch v4.7-rc2

Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild

2016-05-27T05:01:22Z

Pull kbuild updates from Michal Marek: - new option CONFIG_TRIM_UNUSED_KSYMS which does a two-pass build and unexports symbols which are not used in the current config [Nicolas Pitre] - several kbuild rule cleanups [Masahiro Yamada] - warning option adjustments for gcov etc [Arnd Bergmann] - a few more small fixes * 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: (31 commits) kbuild: move -Wunused-const-variable to W=1 warning level kbuild: fix if_change and friends to consider argument order kbuild: fix adjust_autoksyms.sh for modules that need only one symbol kbuild: fix ksym_dep_filter when multiple EXPORT_SYMBOL() on the same line gcov: disable -Wmaybe-uninitialized warning gcov: disable tree-loop-im to reduce stack usage gcov: disable for COMPILE_TEST Kbuild: disable 'maybe-uninitialized' warning for CONFIG_PROFILE_ALL_BRANCHES Kbuild: change CC_OPTIMIZE_FOR_SIZE definition kbuild: forbid kernel directory to contain spaces and colons kbuild: adjust ksym_dep_filter for some cmd_* renames kbuild: Fix dependencies for final vmlinux link kbuild: better abstract vmlinux sequential prerequisites kbuild: fix call to adjust_autoksyms.sh when output directory specified kbuild: Get rid of KBUILD_STR kbuild: rename cmd_as_s_S to cmd_cpp_s_S kbuild: rename cmd_cc_i_c to cmd_cpp_i_c kbuild: drop redundant "PHONY += FORCE" kbuild: delete unnecessary "@:" kbuild: mark help target as PHONY ...

kbuild: Get rid of KBUILD_STR

2016-04-20T08:50:06Z

The compiler can accept -DKBUILD_MODNAME="foo", it's just a matter of quoting. That way, we reduce the gcc command line a bit. Signed-off-by: Michal Marek

dtc: turn off dtc unit address warnings by default

2016-03-31T16:44:16Z

The newly added dtc warning to check DT unit-address without reg property and vice-versa generates lots of warnings. Turn off the check unless building with W=1 or W=2. Signed-off-by: Rob Herring Cc: Michal Marek Cc: linux-kbuild@vger.kernel.org

kernel: add kcov code coverage

2016-03-22T22:36:02Z

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: Dmitry Vyukov Reviewed-by: Kees Cook Cc: syzkaller Cc: Vegard Nossum Cc: Catalin Marinas Cc: Tavis Ormandy Cc: Will Deacon Cc: Quentin Casasnovas Cc: Kostya Serebryany Cc: Eric Dumazet Cc: Alexander Potapenko Cc: Kees Cook Cc: Bjorn Helgaas Cc: Sasha Levin Cc: David Drysdale Cc: Ard Biesheuvel Cc: Andrey Ryabinin Cc: Kirill A. Shutemov Cc: Jiri Slaby Cc: Ingo Molnar Cc: Thomas Gleixner Cc: "H. Peter Anvin" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kbuild: Allow using host dtc instead of kernel's copy

2016-02-23T16:23:55Z

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: Rob Herring Cc: Michal Marek Cc: linux-kbuild@vger.kernel.org

UBSAN: run-time undefined behavior sanity checker

2016-01-21T01:09:18Z

UBSAN uses compile-time instrumentation to catch undefined behavior (UB). Compiler inserts code that perform certain kinds of checks before operations that could cause UB. If check fails (i.e. UB detected) __ubsan_handle_* function called to print error message. So the most of the work is done by compiler. This patch just implements ubsan handlers printing errors. GCC has this capability since 4.9.x [1] (see -fsanitize=undefined option and its suboptions). However GCC 5.x has more checkers implemented [2]. Article [3] has a bit more details about UBSAN in the GCC. [1] - https://gcc.gnu.org/onlinedocs/gcc-4.9.0/gcc/Debugging-Options.html [2] - https://gcc.gnu.org/onlinedocs/gcc/Debugging-Options.html [3] - http://developerblog.redhat.com/2014/10/16/gcc-undefined-behavior-sanitizer-ubsan/ Issues which UBSAN has found thus far are: Found bugs: * out-of-bounds access - 97840cb67ff5 ("netfilter: nfnetlink: fix insufficient validation in nfnetlink_bind") undefined shifts: * d48458d4a768 ("jbd2: use a better hash function for the revoke table") * 10632008b9e1 ("clockevents: Prevent shift out of bounds") * 'x << -1' shift in ext4 - http://lkml.kernel.org/r/<5444EF21.8020501@samsung.com> * undefined rol32(0) - http://lkml.kernel.org/r/<1449198241-20654-1-git-send-email-sasha.levin@oracle.com> * undefined dirty_ratelimit calculation - http://lkml.kernel.org/r/<566594E2.3050306@odin.com> * undefined roundown_pow_of_two(0) - http://lkml.kernel.org/r/<1449156616-11474-1-git-send-email-sasha.levin@oracle.com> * [WONTFIX] undefined shift in __bpf_prog_run - http://lkml.kernel.org/r/ WONTFIX here because it should be fixed in bpf program, not in kernel. signed overflows: * 32a8df4e0b33f ("sched: Fix odd values in effective_load() calculations") * mul overflow in ntp - http://lkml.kernel.org/r/<1449175608-1146-1-git-send-email-sasha.levin@oracle.com> * incorrect conversion into rtc_time in rtc_time64_to_tm() - http://lkml.kernel.org/r/<1449187944-11730-1-git-send-email-sasha.levin@oracle.com> * unvalidated timespec in io_getevents() - http://lkml.kernel.org/r/ * [NOTABUG] signed overflow in ktime_add_safe() - http://lkml.kernel.org/r/ [akpm@linux-foundation.org: fix unused local warning] [akpm@linux-foundation.org: fix __int128 build woes] Signed-off-by: Andrey Ryabinin Cc: Peter Zijlstra Cc: Sasha Levin Cc: Randy Dunlap Cc: Rasmus Villemoes Cc: Jonathan Corbet Cc: Michal Marek Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Yury Gribov Cc: Dmitry Vyukov Cc: Konstantin Khlebnikov Cc: Kostya Serebryany Cc: Johannes Berg Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild

2016-01-20T17:45:43Z

Pull kbuild updates from Michal Marek: - Make -m in makefiles work like -y and fix the fallout - Minor genksyms fix - Fix race with make -j install modules_install - Move -Wsign-compare from make W=1 to W=2 - Other minor fixes * 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: kbuild: Demote 'sign-compare' warning to W=2 Makefile: revert "Makefile: Document ability to make file.lst and file.S" partially kbuild: Do not run modules_install and install in paralel genksyms: Handle string literals with spaces in reference files fixdep: constify strrcmp arguments ath10k: Fix build with CONFIG_THERMAL=m Revert "drm: Hack around CONFIG_AGP=m build failures" kbuild: Allow to specify composite modules with modname-m staging/ad7606: Actually build the interface modules

kbuild: add AFLAGS_REMOVE_(basename).o option

2015-12-18T13:59:25Z

It is already possible to remove CFLAGS with the CFLAGS_REMOVE option that was introduced with commit 656ee82cc855 ("kbuild: create new CFLAGS_REMOVE_(basename).o option"). However it is not possible to remove AFLAGS for assembler files. So this patch just adds the AFLAGS_REMOVE option which works the same like CFLAGS_REMOVE. Signed-off-by: Heiko Carstens Acked-by: Michal Marek Signed-off-by: Martin Schwidefsky

kbuild: Allow to specify composite modules with modname-m

2015-11-25T10:23:25Z

This allows to write drm-$(CONFIG_AGP) += drm_agpsupport.o without having to handle CONFIG_AGP=y vs. CONFIG_AGP=m. Only support this syntax for modules, since built-in code depending on something modular cannot work and init/Makefile actually relies on the current semantics. There are a few drivers which adapted to the current semantics out of necessity; these are fixed to also work when the respective subsystem is modular. Acked-by: Peter Chen [chipidea] Signed-off-by: Michal Marek

kbuild: Create directory for target DTB

2015-04-03T20:52:28Z

When building specific DTBs out of the kernel tree the vendor subdirs (boot/dts/) are not created, ensure that they are before building the DTB. Signed-off-by: Nathan Rossi Signed-off-by: Michal Simek Acked-by: Will Deacon Signed-off-by: Olof Johansson