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 <dvyukov@google.com>
Reviewed-by: Kees 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Bug: 64145065
(cherry-picked from 5c9a8750a6409c63a0f01d51a9024861022f6593)
Change-Id: I17b5e04f6e89b241924e78ec32ead79c38b860ce
Signed-off-by: Paul Lawrence <paullawrence@google.com>
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Conflicts:
kernel/fork.c
Conflict due to Kaiser implementation in LTS 4.4.110.
net/ipv4/raw.c
Minor conflict due to LTS commit
be27b620a8 ("net: ipv4: fix for a race condition in raw_sendmsg")
commit a78f70e8d65e88b9f631d073f68cb26dcd746298 upstream.
The reference files use spaces to separate tokens, however, we must
preserve spaces inside string literals. Currently the only case in the
tree is struct edac_raw_error_desc in <linux/edac.h>:
$ KBUILD_SYMTYPES=1 make -s drivers/edac/amd64_edac.symtypes
$ mv drivers/edac/amd64_edac.{symtypes,symref}
$ KBUILD_SYMTYPES=1 make -s drivers/edac/amd64_edac.symtypes
drivers/edac/amd64_edac.c:527: warning: amd64_get_dram_hole_info: modversion changed because of changes in struct edac_raw_error_desc
Signed-off-by: Michal Marek <mmarek@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 2dbc644ac62bbcb9ee78e84719953f611be0413d ]
For rpm-pkg and deb-pkg, a source tar file is created. All paths in
the archive must be prefixed with the base name of the tar so that
everything is contained in the directory when you extract it.
Currently, scripts/package/Makefile uses a symlink for that, and
removes it after the tar is created.
If you terminate the build during the tar creation, the symlink is
left over. Then, at the next package build, you will see a warning
like follows:
ln: '.' and 'kernel-4.14.0+/.' are the same file
It is possible to fix it by adding -n (--no-dereference) option to
the "ln" command, but a cleaner way is to use --transform option
of "tar" command. This option is GNU extension, but it should not
hurt to use it in the Linux build system.
The 'S' flag is needed to exclude symlinks from the path fixup.
Without it, symlinks in the kernel are broken.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit ab42632156becd35d3884ee5c14da2bedbf3149a ]
For powerpc the __jump_table section in modules is not aligned, this
causes a WARN_ON() splat when loading a module containing a __jump_table.
Strict alignment became necessary with commit 3821fd35b58d
("jump_label: Reduce the size of struct static_key"), currently in
linux-next, which uses the two least significant bits of pointers to
__jump_table elements.
Fix by forcing __jump_table to 8, which is the same alignment used for
this section in the kernel proper.
Link: http://lkml.kernel.org/r/20170301220453.4756-1-david.daney@cavium.com
Reviewed-by: Jason Baron <jbaron@akamai.com>
Acked-by: Jessica Yu <jeyu@redhat.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Tested-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* linux-linaro-lsk-v4.4-android: (510 commits)
Linux 4.4.103
Revert "sctp: do not peel off an assoc from one netns to another one"
xen: xenbus driver must not accept invalid transaction ids
s390/kbuild: enable modversions for symbols exported from asm
ASoC: wm_adsp: Don't overrun firmware file buffer when reading region data
btrfs: return the actual error value from from btrfs_uuid_tree_iterate
ASoC: rsnd: don't double free kctrl
netfilter: nf_tables: fix oob access
netfilter: nft_queue: use raw_smp_processor_id()
spi: SPI_FSL_DSPI should depend on HAS_DMA
staging: iio: cdc: fix improper return value
iio: light: fix improper return value
mac80211: Suppress NEW_PEER_CANDIDATE event if no room
mac80211: Remove invalid flag operations in mesh TSF synchronization
drm: Apply range restriction after color adjustment when allocation
ALSA: hda - Apply ALC269_FIXUP_NO_SHUTUP on HDA_FIXUP_ACT_PROBE
ath10k: set CTS protection VDEV param only if VDEV is up
ath10k: fix potential memory leak in ath10k_wmi_tlv_op_pull_fw_stats()
ath10k: ignore configuring the incorrect board_id
ath10k: fix incorrect txpower set by P2P_DEVICE interface
...
Conflicts:
drivers/media/v4l2-core/v4l2-ctrls.c
kernel/sched/fair.c
Change-Id: I48152b2a0ab1f9f07e1da7823119b94f9b9e1751
cc-option uses KBUILD_CFLAGS and KBUILD_CPPFLAGS when it determines
whether an option is supported or not. This is fine for options used to
build the kernel itself, however some components like the x86 boot code
use a different set of flags.
Add the new macro __cc-option which is a more generic version of
cc-option with additional parameters. One parameter is the compiler
with which the check should be performed, the other the compiler options
to be used instead KBUILD_C*FLAGS.
Refactor cc-option and hostcc-option to use __cc-option and move
hostcc-option to scripts/Kbuild.include.
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Michal Marek <mmarek@suse.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
(cherry picked from commit 9f3f1fd299768782465cb32cdf0dd4528d11f26b)
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Conflicts:
scripts/Kbuild.include
Change-Id: I4c8288b9c74bd6b9199307a0e04b78a27e28361d
Add rules to kbuild in order to generate LLVM assembly files with the .ll
extension when using clang.
# from c code
make CC=clang kernel/pid.ll
Signed-off-by: VinÃcius Tinti <viniciustinti@gmail.com>
Signed-off-by: Behan Webster <behanw@converseincode.com>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
(cherry picked from commit 433db3e260bc8134d4a46ddf20b3668937e12556)
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Change-Id: I1fcc7ec14357e19e46cc2dd1772c5c258aec91d1
Clang will warn about unknown warnings but will not return false
unless -Werror is set. GCC will return false if an unknown
warning is passed.
Adding -Werror make both compiler behave the same.
[arnd: it turns out we need the same patch for testing whether -ffunction-sections
works right with gcc. I've build tested extensively with this patch
applied, so let's just merge this one now.]
Upstream commit: c3f0d0bc5b01
Change-Id: I72c97bab5deaa47adef1bc535dcf19b7d2e0dbdf
Signed-off-by: Mark Charlebois <charlebm@gmail.com>
Signed-off-by: Behan Webster <behanw@converseincode.com>
Reviewed-by: Jan-Simon Mller <dl9pf@gmx.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Since commit c3f0d0bc5b01 ("kbuild, LLVMLinux: Add -Werror to
cc-option to support clang"), cc-option and friends work nicely
for clang.
However, -Wno-unknown-warning-option makes clang happy with any
unknown warning options even if -Werror is specified.
Once -Wno-unknown-warning-option is added, any succeeding call of
cc-disable-warning is evaluated positive, then unknown warning
options are accepted. This should be dropped.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
(cherry picked from commit a0ae981eba8f07dbc74bce38fd3a462b69a5bc8e)
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Change-Id: I0535e20fbcecc2d431e9f08b1f274c5d96626af1
KBuild abuses the asm statement to write to a file and
clang chokes about these invalid asm statements. Hack it
even more by fooling this is actual valid asm code.
[masahiro:
Import Jeroen's work for U-Boot:
http://patchwork.ozlabs.org/patch/375026/
Tweak sed script a little to avoid garbage '#' for GCC case, like
#define NR_PAGEFLAGS 23 /* __NR_PAGEFLAGS # */ ]
Signed-off-by: Jeroen Hofstee <jeroen@myspectrum.nl>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Tested-by: Matthias Kaehlcke <mka@chromium.org>
(cherry picked from commit cf0c3e68aa81f992b0301f62e341b710d385bf68)
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Change-Id: Ifbfd4eff59a7f4304f0d8fdcba4075100244562f
This part ended up in redundant code after touched by multiple
people.
[1] Commit 3234282f33 ("x86, asm: Fix CFI macro invocations to
deal with shortcomings in gas") added parentheses for defined
expressions to support old gas for x86.
[2] Commit a22dcdb003 ("x86, asm: Fix ancient-GAS workaround")
split the pattern into two to avoid parentheses for non-numeric
expressions.
[3] Commit 95a2f6f72d ("Partially revert patch that encloses
asm-offset.h numbers in brackets") removed parentheses from numeric
expressions as well because parentheses in MN10300 assembly have a
special meaning (pointer access).
Apparently, there is a conflict between [1] and [3]. After all,
[3] took precedence, and a long time has passed since then.
Now, merge the two patterns again because the first one is covered
by the other.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
(cherry picked from commit 7dd47b95b0f54f2057d40af6e66d477e3fe95d13)
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Change-Id: Idf9e632df984fbc9cb834e7f7b5d33f21da87dbc
Largely redundant code is used in different places to generate C headers
from offset information extracted from assembly language output.
Consolidate the code in Makefile.lib and use this instead.
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
(cherry picked from commit ebf003f0cfb3705e60d40dedc3ec949176c741af)
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Change-Id: I0acd54dd27c0cf0868f221bd63728a9b67320b25
LSK 17.08 v4.4-android
* tag 'lsk-v4.4-17.08-android': (451 commits)
Linux 4.4.83
pinctrl: samsung: Remove bogus irq_[un]mask from resource management
pinctrl: sunxi: add a missing function of A10/A20 pinctrl driver
pnfs/blocklayout: require 64-bit sector_t
iio: adc: vf610_adc: Fix VALT selection value for REFSEL bits
usb:xhci:Add quirk for Certain failing HP keyboard on reset after resume
usb: quirks: Add no-lpm quirk for Moshi USB to Ethernet Adapter
usb: core: unlink urbs from the tail of the endpoint's urb_list
USB: Check for dropped connection before switching to full speed
uag: Add US_FL_IGNORE_RESIDUE for Initio Corporation INIC-3069
iio: light: tsl2563: use correct event code
iio: accel: bmc150: Always restore device to normal mode after suspend-resume
staging:iio:resolver:ad2s1210 fix negative IIO_ANGL_VEL read
USB: hcd: Mark secondary HCD as dead if the primary one died
usb: musb: fix tx fifo flush handling again
USB: serial: pl2303: add new ATEN device id
USB: serial: cp210x: add support for Qivicon USB ZigBee dongle
USB: serial: option: add D-Link DWM-222 device ID
nfs/flexfiles: fix leak of nfs4_ff_ds_version arrays
fuse: initialize the flock flag in fuse_file on allocation
...
commit 8d81ae05d0176da1c54aeaed697fa34be5c5575e upstream.
As of perl 5, version 26, subversion 0 (v5.26.0) some new warnings have
occurred when running checkpatch.
Unescaped left brace in regex is deprecated here (and will be fatal in
Perl 5.30), passed through in regex; marked by <-- HERE in m/^(.\s*){
<-- HERE \s*/ at scripts/checkpatch.pl line 3544.
Unescaped left brace in regex is deprecated here (and will be fatal in
Perl 5.30), passed through in regex; marked by <-- HERE in m/^(.\s*){
<-- HERE \s*/ at scripts/checkpatch.pl line 3885.
Unescaped left brace in regex is deprecated here (and will be fatal in
Perl 5.30), passed through in regex; marked by <-- HERE in
m/^(\+.*(?:do|\))){ <-- HERE / at scripts/checkpatch.pl line 4374.
It seems perfectly reasonable to do as the warning suggests and simply
escape the left brace in these three locations.
Link: http://lkml.kernel.org/r/20170607060135.17384-1-cyrilbur@gmail.com
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add missing support for the devm_request_threaded_irq in
the rules of context, report and org modes.
Misc:
----
To be consistent with other scripts, change confidence level
of the script to 'Moderate'.
Change-Id: I3ad8fc93081be82512e6143e27c8936c988a98f1
Signed-off-by: Vaishali Thakkar <vaishali.thakkar@oracle.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.com>
Signed-off-by: Huang, Tao <huangtao@rock-chips.com>
(cherry picked from commit d1e774f49f0305092c9975d9070aefe318f49872)
To eliminate false positives given by the context mode, add
necessary arguments for the function request_threaded_irq.
Change-Id: I692db266239a03964d17505108e700bc1ffa9bd3
Signed-off-by: Vaishali Thakkar <vaishali.thakkar@oracle.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.com>
Signed-off-by: Huang, Tao <huangtao@rock-chips.com>
(cherry picked from commit 35b303ae361611a6b418e385fee06fa08732b2e6)
Currently because of the left associativity of the operators, pattern
IRQF_ONESHOT | flags does not match with the pattern when we have more
than one flag after the disjunction. This eventually results in giving
false positives by the script. This patch eliminates these FPs by
improving the rule.
Change-Id: I1043d1e6fca848997982305cd8fb3ac2706e7f1f
Signed-off-by: Vaishali Thakkar <vaishali.thakkar@oracle.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
Signed-off-by: Huang, Tao <huangtao@rock-chips.com>
(cherry picked from commit dca24c4544d96989f521b5aa49fd44ae0ae5a5b6)
Add a script to check for unneeded conversions to bool.
Change-Id: I881d423eb72595b11a861eaf01c0c8eb8f262e05
Signed-off-by: Andrew F. Davis <afd@ti.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.com>
Signed-off-by: Huang, Tao <huangtao@rock-chips.com>
(cherry picked from commit 75238b9e6aadca6d9255d4b385e026385e78bb15)
