As Documentation/kbuild/kconfig-language.txt notes, 'select' should be
be used with care - it forces a lower limit of another symbol, ignoring
the dependency. Currently, KCOV can select GCC_PLUGINS even if arch
does not select HAVE_GCC_PLUGINS. This could cause the unmet direct
dependency.
Now that Kconfig can test compiler capability, let's handle this in a
more sophisticated way.
There are two ways to enable KCOV; use the compiler that natively
supports -fsanitize-coverage=trace-pc, or build the SANCOV plugin if
the compiler has ability to build GCC plugins. Hence, the correct
dependency for KCOV is:
depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
You do not need to build the SANCOV plugin if the compiler already
supports -fsanitize-coverage=trace-pc. Hence, the select should be:
select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
With this, GCC_PLUGIN_SANCOV is selected only when necessary, so
scripts/Makefile.gcc-plugins can be cleaner.
I also cleaned up Kconfig and scripts/Makefile.kcov as well.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Pull overflow updates from Kees Cook:
"This adds the new overflow checking helpers and adds them to the
2-factor argument allocators. And this adds the saturating size
helpers and does a treewide replacement for the struct_size() usage.
Additionally this adds the overflow testing modules to make sure
everything works.
I'm still working on the treewide replacements for allocators with
"simple" multiplied arguments:
*alloc(a * b, ...) -> *alloc_array(a, b, ...)
and
*zalloc(a * b, ...) -> *calloc(a, b, ...)
as well as the more complex cases, but that's separable from this
portion of the series. I expect to have the rest sent before -rc1
closes; there are a lot of messy cases to clean up.
Summary:
- Introduce arithmetic overflow test helper functions (Rasmus)
- Use overflow helpers in 2-factor allocators (Kees, Rasmus)
- Introduce overflow test module (Rasmus, Kees)
- Introduce saturating size helper functions (Matthew, Kees)
- Treewide use of struct_size() for allocators (Kees)"
* tag 'overflow-v4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
treewide: Use struct_size() for devm_kmalloc() and friends
treewide: Use struct_size() for vmalloc()-family
treewide: Use struct_size() for kmalloc()-family
device: Use overflow helpers for devm_kmalloc()
mm: Use overflow helpers in kvmalloc()
mm: Use overflow helpers in kmalloc_array*()
test_overflow: Add memory allocation overflow tests
overflow.h: Add allocation size calculation helpers
test_overflow: Report test failures
test_overflow: macrofy some more, do more tests for free
lib: add runtime test of check_*_overflow functions
compiler.h: enable builtin overflow checkers and add fallback code
This adds a small module for testing that the check_*_overflow
functions work as expected, whether implemented in C or using gcc
builtins.
Example output:
test_overflow: u8 : 18 tests
test_overflow: s8 : 19 tests
test_overflow: u16: 17 tests
test_overflow: s16: 17 tests
test_overflow: u32: 17 tests
test_overflow: s32: 17 tests
test_overflow: u64: 17 tests
test_overflow: s64: 21 tests
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
[kees: add output to commit log, drop u64 tests on 32-bit]
Signed-off-by: Kees Cook <keescook@chromium.org>
Drivers/subsystems creating scatterlists for DMA should be taking care
to respect the scatter-gather limitations of the appropriate device, as
described by dma_parms. A DMA API implementation cannot feasibly split
a scatterlist into *more* entries than originally passed, so it is not
well defined what they should do when given a segment larger than the
limit they are also required to respect.
Conversely, devices which are less limited than the rather conservative
defaults, or indeed have no limitations at all (e.g. GPUs with their own
internal MMU), should be encouraged to set appropriate dma_parms, as
they may get more efficient DMA mapping performance out of it.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
This way we have one central definition of it, and user can select it as
needed. Note that we now also always select it when CONFIG_DMA_API_DEBUG
is select, which fixes some incorrect checks in a few network drivers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
There is no arch specific code required for dma-debug, so there is no
need to opt into the support either.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Pull Kbuild updates from Masahiro Yamada:
- add a shell script to get Clang version
- improve portability of build scripts
- drop always-enabled CONFIG_THIN_ARCHIVE and remove unused code
- rename built-in.o which is now thin archive to built-in.a
- process clean/build targets one by one to get along with -j option
- simplify ld-option
- improve building with CONFIG_TRIM_UNUSED_KSYMS
- define KBUILD_MODNAME even for objects shared among multiple modules
- avoid linking multiple instances of same objects from composite
objects
- move <linux/compiler_types.h> to c_flags to include it only for C
files
- clean-up various Makefiles
* tag 'kbuild-v4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (29 commits)
kbuild: get <linux/compiler_types.h> out of <linux/kconfig.h>
kbuild: clean up link rule of composite modules
kbuild: clean up archive rule of built-in.a
kbuild: remove partial section mismatch detection for built-in.a
net: liquidio: clean up Makefile for simpler composite object handling
lib: zstd: clean up Makefile for simpler composite object handling
kbuild: link $(real-obj-y) instead of $(obj-y) into built-in.a
kbuild: rename real-objs-y/m to real-obj-y/m
kbuild: move modname and modname-multi close to modname_flags
kbuild: simplify modname calculation
kbuild: fix modname for composite modules
kbuild: define KBUILD_MODNAME even if multiple modules share objects
kbuild: remove unnecessary $(subst $(obj)/, , ...) in modname-multi
kbuild: Use ls(1) instead of stat(1) to obtain file size
kbuild: link vmlinux only once for CONFIG_TRIM_UNUSED_KSYMS
kbuild: move include/config/ksym/* to include/ksym/*
kbuild: move CONFIG_TRIM_UNUSED_KSYMS code unneeded for external module
kbuild: restore autoksyms.h touch to the top Makefile
kbuild: move 'scripts' target below
kbuild: remove wrong 'touch' in adjust_autoksyms.sh
...
Pul removal of obsolete architecture ports from Arnd Bergmann:
"This removes the entire architecture code for blackfin, cris, frv,
m32r, metag, mn10300, score, and tile, including the associated device
drivers.
I have been working with the (former) maintainers for each one to
ensure that my interpretation was right and the code is definitely
unused in mainline kernels. Many had fond memories of working on the
respective ports to start with and getting them included in upstream,
but also saw no point in keeping the port alive without any users.
In the end, it seems that while the eight architectures are extremely
different, they all suffered the same fate: There was one company in
charge of an SoC line, a CPU microarchitecture and a software
ecosystem, which was more costly than licensing newer off-the-shelf
CPU cores from a third party (typically ARM, MIPS, or RISC-V). It
seems that all the SoC product lines are still around, but have not
used the custom CPU architectures for several years at this point. In
contrast, CPU instruction sets that remain popular and have actively
maintained kernel ports tend to all be used across multiple licensees.
[ See the new nds32 port merged in the previous commit for the next
generation of "one company in charge of an SoC line, a CPU
microarchitecture and a software ecosystem" - Linus ]
The removal came out of a discussion that is now documented at
https://lwn.net/Articles/748074/. Unlike the original plans, I'm not
marking any ports as deprecated but remove them all at once after I
made sure that they are all unused. Some architectures (notably tile,
mn10300, and blackfin) are still being shipped in products with old
kernels, but those products will never be updated to newer kernel
releases.
After this series, we still have a few architectures without mainline
gcc support:
- unicore32 and hexagon both have very outdated gcc releases, but the
maintainers promised to work on providing something newer. At least
in case of hexagon, this will only be llvm, not gcc.
- openrisc, risc-v and nds32 are still in the process of finishing
their support or getting it added to mainline gcc in the first
place. They all have patched gcc-7.3 ports that work to some
degree, but complete upstream support won't happen before gcc-8.1.
Csky posted their first kernel patch set last week, their situation
will be similar
[ Palmer Dabbelt points out that RISC-V support is in mainline gcc
since gcc-7, although gcc-7.3.0 is the recommended minimum - Linus ]"
This really says it all:
2498 files changed, 95 insertions(+), 467668 deletions(-)
* tag 'arch-removal' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: (74 commits)
MAINTAINERS: UNICORE32: Change email account
staging: iio: remove iio-trig-bfin-timer driver
tty: hvc: remove tile driver
tty: remove bfin_jtag_comm and hvc_bfin_jtag drivers
serial: remove tile uart driver
serial: remove m32r_sio driver
serial: remove blackfin drivers
serial: remove cris/etrax uart drivers
usb: Remove Blackfin references in USB support
usb: isp1362: remove blackfin arch glue
usb: musb: remove blackfin port
usb: host: remove tilegx platform glue
pwm: remove pwm-bfin driver
i2c: remove bfin-twi driver
spi: remove blackfin related host drivers
watchdog: remove bfin_wdt driver
can: remove bfin_can driver
mmc: remove bfin_sdh driver
input: misc: remove blackfin rotary driver
input: keyboard: remove bf54x driver
...
A lot of Kconfig symbols have architecture specific dependencies.
In those cases that depend on architectures we have already removed,
they can be omitted.
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Incremental linking is gone, so rename built-in.o to built-in.a, which
is the usual extension for archive files.
This patch does two things, first is a simple search/replace:
git grep -l 'built-in\.o' | xargs sed -i 's/built-in\.o/built-in\.a/g'
The second is to invert nesting of nested text manipulations to avoid
filtering built-in.a out from libs-y2:
-libs-y2 := $(filter-out %.a, $(patsubst %/, %/built-in.a, $(libs-y)))
+libs-y2 := $(patsubst %/, %/built-in.a, $(filter-out %.a, $(libs-y)))
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Remove metag architecture
These patches remove the metag architecture and tightly dependent
drivers from the kernel. With the 4.16 kernel the ancient gcc 4.2.4
based metag toolchain we have been using is hitting compiler bugs, so
now seems a good time to drop it altogether.
* tag 'metag_remove_2' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/jhogan/metag:
i2c: img-scb: Drop METAG dependency
media: img-ir: Drop METAG dependency
watchdog: imgpdc: Drop METAG dependency
MAINTAINERS/CREDITS: Drop METAG ARCHITECTURE
tty: Remove metag DA TTY and console driver
clocksource: Remove metag generic timer driver
irqchip: Remove metag irqchip drivers
Drop a bunch of metag references
docs: Remove remaining references to metag
docs: Remove metag docs
metag: Remove arch/metag/
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Pull more Kbuild updates from Masahiro Yamada:
"Makefile changes:
- enable unused-variable warning that was wrongly disabled for clang
Kconfig changes:
- warn about blank 'help' and fix existing instances
- fix 'choice' behavior to not write out invisible symbols
- fix misc weirdness
Coccinell changes:
- fix false positive of free after managed memory alloc detection
- improve performance of NULL dereference detection"
* tag 'kbuild-v4.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (21 commits)
kconfig: remove const qualifier from sym_expand_string_value()
kconfig: add xrealloc() helper
kconfig: send error messages to stderr
kconfig: echo stdin to stdout if either is redirected
kconfig: remove check_stdin()
kconfig: remove 'config*' pattern from .gitignnore
kconfig: show '?' prompt even if no help text is available
kconfig: do not write choice values when their dependency becomes n
coccinelle: deref_null: avoid useless computation
coccinelle: devm_free: reduce false positives
kbuild: clang: disable unused variable warnings only when constant
kconfig: Warn if help text is blank
nios2: kconfig: Remove blank help text
arm: vt8500: kconfig: Remove blank help text
MIPS: kconfig: Remove blank help text
MIPS: BCM63XX: kconfig: Remove blank help text
lib/Kconfig.debug: Remove blank help text
Staging: rtl8192e: kconfig: Remove blank help text
Staging: rtl8192u: kconfig: Remove blank help text
mmc: kconfig: Remove blank help text
...
We get a lot of very large stack frames using gcc-7.0.1 with the default
-fsanitize-address-use-after-scope --param asan-stack=1 options, which can
easily cause an overflow of the kernel stack, e.g.
drivers/gpu/drm/i915/gvt/handlers.c:2434:1: warning: the frame size of 46176 bytes is larger than 3072 bytes
drivers/net/wireless/ralink/rt2x00/rt2800lib.c:5650:1: warning: the frame size of 23632 bytes is larger than 3072 bytes
lib/atomic64_test.c:250:1: warning: the frame size of 11200 bytes is larger than 3072 bytes
drivers/gpu/drm/i915/gvt/handlers.c:2621:1: warning: the frame size of 9208 bytes is larger than 3072 bytes
drivers/media/dvb-frontends/stv090x.c:3431:1: warning: the frame size of 6816 bytes is larger than 3072 bytes
fs/fscache/stats.c:287:1: warning: the frame size of 6536 bytes is larger than 3072 bytes
To reduce this risk, -fsanitize-address-use-after-scope is now split out
into a separate CONFIG_KASAN_EXTRA Kconfig option, leading to stack
frames that are smaller than 2 kilobytes most of the time on x86_64. An
earlier version of this patch also prevented combining KASAN_EXTRA with
KASAN_INLINE, but that is no longer necessary with gcc-7.0.1.
All patches to get the frame size below 2048 bytes with CONFIG_KASAN=y
and CONFIG_KASAN_EXTRA=n have been merged by maintainers now, so we can
bring back that default now. KASAN_EXTRA=y still causes lots of
warnings but now defaults to !COMPILE_TEST to disable it in
allmodconfig, and it remains disabled in all other defconfigs since it
is a new option. I arbitrarily raise the warning limit for KASAN_EXTRA
to 3072 to reduce the noise, but an allmodconfig kernel still has around
50 warnings on gcc-7.
I experimented a bit more with smaller stack frames and have another
follow-up series that reduces the warning limit for 64-bit architectures
to 1280 bytes (without CONFIG_KASAN).
With earlier versions of this patch series, I also had patches to address
the warnings we get with KASAN and/or KASAN_EXTRA, using a
"noinline_if_stackbloat" annotation.
That annotation now got replaced with a gcc-8 bugfix (see
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81715) and a workaround for
older compilers, which means that KASAN_EXTRA is now just as bad as
before and will lead to an instant stack overflow in a few extreme
cases.
This reverts parts of commit 3f181b4d86 ("lib/Kconfig.debug: disable
-Wframe-larger-than warnings with KASAN=y"). Two patches in linux-next
should be merged first to avoid introducing warnings in an allmodconfig
build:
3cd890dbe2 ("media: dvb-frontends: fix i2c access helpers for KASAN")
16c3ada89c ("media: r820t: fix r820t_write_reg for KASAN")
Do we really need to backport this?
I think we do: without this patch, enabling KASAN will lead to
unavoidable kernel stack overflow in certain device drivers when built
with gcc-7 or higher on linux-4.10+ or any version that contains a
backport of commit c5caf21ab0. Most people are probably still on
older compilers, but it will get worse over time as they upgrade their
distros.
The warnings we get on kernels older than this should all be for code
that uses dangerously large stack frames, though most of them do not
cause an actual stack overflow by themselves.The asan-stack option was
added in linux-4.0, and commit 3f181b4d86 ("lib/Kconfig.debug:
disable -Wframe-larger-than warnings with KASAN=y") effectively turned
off the warning for allmodconfig kernels, so I would like to see this
fix backported to any kernels later than 4.0.
I have done dozens of fixes for individual functions with stack frames
larger than 2048 bytes with asan-stack, and I plan to make sure that
all those fixes make it into the stable kernels as well (most are
already there).
Part of the complication here is that asan-stack (from 4.0) was
originally assumed to always require much larger stacks, but that
turned out to be a combination of multiple gcc bugs that we have now
worked around and fixed, but sanitize-address-use-after-scope (from
v4.10) has a much higher inherent stack usage and also suffers from at
least three other problems that we have analyzed but not yet fixed
upstream, each of them makes the stack usage more severe than it should
be.
Link: http://lkml.kernel.org/r/20171221134744.2295529-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Blank help texts are probably either a typo, a Kconfig misunderstanding,
or some kind of half-committing to adding a help text (in which case a
TODO comment would be clearer, if the help text really can't be added
right away).
Best to remove them, IMO.
Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Pull networking updates from David Miller:
1) Significantly shrink the core networking routing structures. Result
of http://vger.kernel.org/~davem/seoul2017_netdev_keynote.pdf
2) Add netdevsim driver for testing various offloads, from Jakub
Kicinski.
3) Support cross-chip FDB operations in DSA, from Vivien Didelot.
4) Add a 2nd listener hash table for TCP, similar to what was done for
UDP. From Martin KaFai Lau.
5) Add eBPF based queue selection to tun, from Jason Wang.
6) Lockless qdisc support, from John Fastabend.
7) SCTP stream interleave support, from Xin Long.
8) Smoother TCP receive autotuning, from Eric Dumazet.
9) Lots of erspan tunneling enhancements, from William Tu.
10) Add true function call support to BPF, from Alexei Starovoitov.
11) Add explicit support for GRO HW offloading, from Michael Chan.
12) Support extack generation in more netlink subsystems. From Alexander
Aring, Quentin Monnet, and Jakub Kicinski.
13) Add 1000BaseX, flow control, and EEE support to mvneta driver. From
Russell King.
14) Add flow table abstraction to netfilter, from Pablo Neira Ayuso.
15) Many improvements and simplifications to the NFP driver bpf JIT,
from Jakub Kicinski.
16) Support for ipv6 non-equal cost multipath routing, from Ido
Schimmel.
17) Add resource abstration to devlink, from Arkadi Sharshevsky.
18) Packet scheduler classifier shared filter block support, from Jiri
Pirko.
19) Avoid locking in act_csum, from Davide Caratti.
20) devinet_ioctl() simplifications from Al viro.
21) More TCP bpf improvements from Lawrence Brakmo.
22) Add support for onlink ipv6 route flag, similar to ipv4, from David
Ahern.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1925 commits)
tls: Add support for encryption using async offload accelerator
ip6mr: fix stale iterator
net/sched: kconfig: Remove blank help texts
openvswitch: meter: Use 64-bit arithmetic instead of 32-bit
tcp_nv: fix potential integer overflow in tcpnv_acked
r8169: fix RTL8168EP take too long to complete driver initialization.
qmi_wwan: Add support for Quectel EP06
rtnetlink: enable IFLA_IF_NETNSID for RTM_NEWLINK
ipmr: Fix ptrdiff_t print formatting
ibmvnic: Wait for device response when changing MAC
qlcnic: fix deadlock bug
tcp: release sk_frag.page in tcp_disconnect
ipv4: Get the address of interface correctly.
net_sched: gen_estimator: fix lockdep splat
net: macb: Handle HRESP error
net/mlx5e: IPoIB, Fix copy-paste bug in flow steering refactoring
ipv6: addrconf: break critical section in addrconf_verify_rtnl()
ipv6: change route cache aging logic
i40e/i40evf: Update DESC_NEEDED value to reflect larger value
bnxt_en: cleanup DIM work on device shutdown
...
