Prasad reported that he has seen crashes in BPF subsystem with netd
on Android with arm64 in the form of (note, the taint is unrelated):
[ 4134.721483] Unable to handle kernel paging request at virtual address 800000001
[ 4134.820925] Mem abort info:
[ 4134.901283] Exception class = DABT (current EL), IL = 32 bits
[ 4135.016736] SET = 0, FnV = 0
[ 4135.119820] EA = 0, S1PTW = 0
[ 4135.201431] Data abort info:
[ 4135.301388] ISV = 0, ISS = 0x00000021
[ 4135.359599] CM = 0, WnR = 0
[ 4135.470873] user pgtable: 4k pages, 39-bit VAs, pgd = ffffffe39b946000
[ 4135.499757] [0000000800000001] *pgd=0000000000000000, *pud=0000000000000000
[ 4135.660725] Internal error: Oops: 96000021 [#1] PREEMPT SMP
[ 4135.674610] Modules linked in:
[ 4135.682883] CPU: 5 PID: 1260 Comm: netd Tainted: G S W 4.14.19+ #1
[ 4135.716188] task: ffffffe39f4aa380 task.stack: ffffff801d4e0000
[ 4135.731599] PC is at bpf_prog_add+0x20/0x68
[ 4135.741746] LR is at bpf_prog_inc+0x20/0x2c
[ 4135.751788] pc : [<ffffff94ab7ad584>] lr : [<ffffff94ab7ad638>] pstate: 60400145
[ 4135.769062] sp : ffffff801d4e3ce0
[...]
[ 4136.258315] Process netd (pid: 1260, stack limit = 0xffffff801d4e0000)
[ 4136.273746] Call trace:
[...]
[ 4136.442494] 3ca0: ffffff94ab7ad584 0000000060400145 ffffffe3a01bf8f8 0000000000000006
[ 4136.460936] 3cc0: 0000008000000000 ffffff94ab844204 ffffff801d4e3cf0 ffffff94ab7ad584
[ 4136.479241] [<ffffff94ab7ad584>] bpf_prog_add+0x20/0x68
[ 4136.491767] [<ffffff94ab7ad638>] bpf_prog_inc+0x20/0x2c
[ 4136.504536] [<ffffff94ab7b5d08>] bpf_obj_get_user+0x204/0x22c
[ 4136.518746] [<ffffff94ab7ade68>] SyS_bpf+0x5a8/0x1a88
Android's netd was basically pinning the uid cookie BPF map in BPF
fs (/sys/fs/bpf/traffic_cookie_uid_map) and later on retrieving it
again resulting in above panic. Issue is that the map was wrongly
identified as a prog! Above kernel was compiled with clang 4.0,
and it turns out that clang decided to merge the bpf_prog_iops and
bpf_map_iops into a single memory location, such that the two i_ops
could then not be distinguished anymore.
Reason for this miscompilation is that clang has the more aggressive
-fmerge-all-constants enabled by default. In fact, clang source code
has a comment about it in lib/AST/ExprConstant.cpp on why it is okay
to do so:
Pointers with different bases cannot represent the same object.
(Note that clang defaults to -fmerge-all-constants, which can
lead to inconsistent results for comparisons involving the address
of a constant; this generally doesn't matter in practice.)
The issue never appeared with gcc however, since gcc does not enable
-fmerge-all-constants by default and even *explicitly* states in
it's option description that using this flag results in non-conforming
behavior, quote from man gcc:
Languages like C or C++ require each variable, including multiple
instances of the same variable in recursive calls, to have distinct
locations, so using this option results in non-conforming behavior.
There are also various clang bug reports open on that matter [1],
where clang developers acknowledge the non-conforming behavior,
and refer to disabling it with -fno-merge-all-constants. But even
if this gets fixed in clang today, there are already users out there
that triggered this. Thus, fix this issue by explicitly adding
-fno-merge-all-constants to the kernel's Makefile to generically
disable this optimization, since potentially other places in the
kernel could subtly break as well.
Note, there is also a flag called -fmerge-constants (not supported
by clang), which is more conservative and only applies to strings
and it's enabled in gcc's -O/-O2/-O3/-Os optimization levels. In
gcc's code, the two flags -fmerge-{all-,}constants share the same
variable internally, so when disabling it via -fno-merge-all-constants,
then we really don't merge any const data (e.g. strings), and text
size increases with gcc (14,927,214 -> 14,942,646 for vmlinux.o).
$ gcc -fverbose-asm -O2 foo.c -S -o foo.S
-> foo.S lists -fmerge-constants under options enabled
$ gcc -fverbose-asm -O2 -fno-merge-all-constants foo.c -S -o foo.S
-> foo.S doesn't list -fmerge-constants under options enabled
$ gcc -fverbose-asm -O2 -fno-merge-all-constants -fmerge-constants foo.c -S -o foo.S
-> foo.S lists -fmerge-constants under options enabled
Thus, as a workaround we need to set both -fno-merge-all-constants
*and* -fmerge-constants in the Makefile in order for text size to
stay as is.
[1] https://bugs.llvm.org/show_bug.cgi?id=18538
Reported-by: Prasad Sodagudi <psodagud@codeaurora.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Chenbo Feng <fengc@google.com>
Cc: Richard Smith <richard-llvm@metafoo.co.uk>
Cc: Chandler Carruth <chandlerc@gmail.com>
Cc: linux-kernel@vger.kernel.org
Tested-by: Prasad Sodagudi <psodagud@codeaurora.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
- suppress sparse warnings about unknown attributes
- fix typos and stale comments
- fix build error of arch/sh
- fix wrong use of ld-option vs cc-ldoption
- remove redundant GCC_PLUGINS_CFLAGS assignment
- fix another memory leak of Kconfig
- fix line number in error messages of Kconfig
- do not write confusing CONFIG_DEFCONFIG_LIST out to .config
- add xstrdup() to Kconfig to handle memory shortage errors
- show also a Debian package name if ncurses is missing
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Merge tag 'kbuild-fixes-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild fixes from Masahiro Yamada:
- suppress sparse warnings about unknown attributes
- fix typos and stale comments
- fix build error of arch/sh
- fix wrong use of ld-option vs cc-ldoption
- remove redundant GCC_PLUGINS_CFLAGS assignment
- fix another memory leak of Kconfig
- fix line number in error messages of Kconfig
- do not write confusing CONFIG_DEFCONFIG_LIST out to .config
- add xstrdup() to Kconfig to handle memory shortage errors
- show also a Debian package name if ncurses is missing
* tag 'kbuild-fixes-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
MAINTAINERS: take over Kconfig maintainership
kconfig: fix line number in recursive inclusion error message
Coccinelle: memdup: Fix typo in warning messages
kconfig: Update ncurses package names for menuconfig
kbuild/kallsyms: trivial typo fix
kbuild: test --build-id linker flag by ld-option instead of cc-ldoption
kbuild: drop superfluous GCC_PLUGINS_CFLAGS assignment
kconfig: Don't leak choice names during parsing
sh: fix build error for empty CONFIG_BUILTIN_DTB_SOURCE
kconfig: set SYMBOL_AUTO to the symbol marked with defconfig_list
kconfig: add xstrdup() helper
kbuild: disable sparse warnings about unknown attributes
Makefile: Fix lying comment re. silentoldconfig
'--build-id' is passed to $(LD), so it should be tested by 'ld-option'.
This seems a kind of misconversion when ld-option was renamed to
cc-ldoption.
Commit f86fd30660 ("kbuild: rename ld-option to cc-ldoption") renamed
all instances of 'ld-option' to 'cc-ldoption'.
Then, commit 691ef3e7fd ("kbuild: introduce ld-option") re-added
'ld-option' as a new implementation.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Currently, sparse issues warnings on code using an attribute
it doesn't know about.
One of the problem with this is that these warnings have no
value for the developer, it's just noise for him. At best these
warnings tell something about some deficiencies of sparse itself
but not about a potential problem with code analyzed.
A second problem with this is that sparse release are, alas,
less frequent than new attributes are added to GCC.
So, avoid the noise by asking sparse to not warn about
attributes it doesn't know about.
Reference: https://marc.info/?l=linux-sparse&m=151871600016790
Reference: https://marc.info/?l=linux-sparse&m=151871725417322
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
The comment above the silentoldconfig invocation is outdated.
'make oldconfig' updates just .config and doesn't touch the
include/config/ tree.
This came up in https://lkml.org/lkml/2018/2/12/415.
While fixing the comment, make it more informative by explaining the
purpose of the unfortunately named silentoldconfig.
I can't make sense of the comment re. auto.conf.cmd and a cleaned tree.
include/config/auto.conf and include/config/auto.conf.cmd are both
created simultaneously by silentoldconfig (in
scripts/kconfig/confdata.c, by conf_write_autoconf()), and nothing seems
to remove auto.conf.cmd that wouldn't remove auto.conf. Remove that part
of the comment rather than blindly copying it. It might be a leftover
from an older way of doing things.
The include/config/auto.conf.cmd prerequisite might be there to ensure
that silentoldconfig gets rerun if conf_write_autoconf() fails between
writing out auto.conf.cmd and auto.conf (a comment in the function
indicates that auto.conf is deliberately written out last to mark
completion of the operation). It seems the Makefile dependency between
include/config/auto.conf and .config would already take care of that
though, since include/config/auto.conf would still be out of date re.
.config if the operation fails.
Cop out and leave the prerequisite in for now.
Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Pull x86 fixes from Thomas Gleixner:
"Yet another pile of melted spectrum related changes:
- sanitize the array_index_nospec protection mechanism: Remove the
overengineered array_index_nospec_mask_check() magic and allow
const-qualified types as index to avoid temporary storage in a
non-const local variable.
- make the microcode loader more robust by properly propagating error
codes. Provide information about new feature bits after micro code
was updated so administrators can act upon.
- optimizations of the entry ASM code which reduce code footprint and
make the code simpler and faster.
- fix the {pmd,pud}_{set,clear}_flags() implementations to work
properly on paravirt kernels by removing the address translation
operations.
- revert the harmful vmexit_fill_RSB() optimization
- use IBRS around firmware calls
- teach objtool about retpolines and add annotations for indirect
jumps and calls.
- explicitly disable jumplabel patching in __init code and handle
patching failures properly instead of silently ignoring them.
- remove indirect paravirt calls for writing the speculation control
MSR as these calls are obviously proving the same attack vector
which is tried to be mitigated.
- a few small fixes which address build issues with recent compiler
and assembler versions"
* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (38 commits)
KVM/VMX: Optimize vmx_vcpu_run() and svm_vcpu_run() by marking the RDMSR path as unlikely()
KVM/x86: Remove indirect MSR op calls from SPEC_CTRL
objtool, retpolines: Integrate objtool with retpoline support more closely
x86/entry/64: Simplify ENCODE_FRAME_POINTER
extable: Make init_kernel_text() global
jump_label: Warn on failed jump_label patching attempt
jump_label: Explicitly disable jump labels in __init code
x86/entry/64: Open-code switch_to_thread_stack()
x86/entry/64: Move ASM_CLAC to interrupt_entry()
x86/entry/64: Remove 'interrupt' macro
x86/entry/64: Move the switch_to_thread_stack() call to interrupt_entry()
x86/entry/64: Move ENTER_IRQ_STACK from interrupt macro to interrupt_entry
x86/entry/64: Move PUSH_AND_CLEAR_REGS from interrupt macro to helper function
x86/speculation: Move firmware_restrict_branch_speculation_*() from C to CPP
objtool: Add module specific retpoline rules
objtool: Add retpoline validation
objtool: Use existing global variables for options
x86/mm/sme, objtool: Annotate indirect call in sme_encrypt_execute()
x86/boot, objtool: Annotate indirect jump in secondary_startup_64()
x86/paravirt, objtool: Annotate indirect calls
...
Disable retpoline validation in objtool if your compiler sucks, and otherwise
select the validation stuff for CONFIG_RETPOLINE=y (most builds would already
have it set due to ORC).
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Makefile changes:
- enable unused-variable warning that was wrongly disabled for clang
Kconfig changes:
- warn 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
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Merge tag 'kbuild-v4.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
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
...
Nearly all modern compilers support a stack-protector option, and nearly
all modern distributions enable the kernel stack-protector, so enabling
this by default in kernel builds would make sense. However, Kconfig does
not have knowledge of available compiler features, so it isn't safe to
force on, as this would unconditionally break builds for the compilers or
architectures that don't have support. Instead, this introduces a new
option, CONFIG_CC_STACKPROTECTOR_AUTO, which attempts to discover the best
possible stack-protector available, and will allow builds to proceed even
if the compiler doesn't support any stack-protector.
This option is made the default so that kernels built with modern
compilers will be protected-by-default against stack buffer overflows,
avoiding things like the recent BlueBorne attack. Selection of a specific
stack-protector option remains available, including disabling it.
Additionally, tiny.config is adjusted to use CC_STACKPROTECTOR_NONE, since
that's the option with the least code size (and it used to be the default,
so we have to explicitly choose it there now).
Link: http://lkml.kernel.org/r/1510076320-69931-4-git-send-email-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: Laura Abbott <labbott@redhat.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Various portions of the kernel, especially per-architecture pieces,
need to know if the compiler is building with the stack protector.
This was done in the arch/Kconfig with 'select', but this doesn't
allow a way to do auto-detected compiler support. In preparation for
creating an on-if-available default, move the logic for the definition of
CONFIG_CC_STACKPROTECTOR into the Makefile.
Link: http://lkml.kernel.org/r/1510076320-69931-3-git-send-email-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: Laura Abbott <labbott@redhat.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In order to make stack-protector failures warn instead of unconditionally
breaking the build, this moves the compiler output sanity-check earlier,
and sets a flag for later testing. Future patches can choose to warn or
fail, depending on the flag value.
Link: http://lkml.kernel.org/r/1510076320-69931-2-git-send-email-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: Laura Abbott <labbott@redhat.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With KASAN enabled the kernel has two different memset() functions, one
with KASAN checks (memset) and one without (__memset). KASAN uses some
macro tricks to use the proper version where required. For example
memset() calls in mm/slub.c are without KASAN checks, since they operate
on poisoned slab object metadata.
The issue is that clang emits memset() calls even when there is no
memset() in the source code. They get linked with improper memset()
implementation and the kernel fails to boot due to a huge amount of KASAN
reports during early boot stages.
The solution is to add -fno-builtin flag for files with KASAN_SANITIZE :=
n marker.
Link: http://lkml.kernel.org/r/8ffecfffe04088c52c42b92739c2bd8a0bcb3f5e.1516384594.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@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>
Currently, GCC disables -Wunused-const-variable, but not
-Wunused-variable, so warns unused variables if they are
non-constant.
While, Clang does not warn unused variables at all regardless of
the const qualifier because -Wno-unused-const-variable is implied
by the stronger option -Wno-unused-variable.
Disable -Wunused-const-variable instead of -Wunused-variable so that
GCC and Clang work in the same way.
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
A pretty big batch of Kconfig updates. I have to mention the lexer
and parser of Kconfig are now built from real .l and .y sources.
So, flex and bison are the requirement for building the kernel.
Both of them (unlike gperf) have been stable for a long time. This
change has been tested several weeks in linux-next, and I did not
receive any problem report about this.
Summary:
- Add checks for mistakes, like the choice default is not in
choice, help is doubled
- Document data structure and complex code
- Fix various memory leaks
- Change Makefile to build lexer and parser instead of using
pre-generated C files
- Drop 'boolean' keyword, which is equivalent to 'bool'
- Use default 'yy' prefix and remove unneeded Make variables
- Fix gettext() check for xconfig
- Announce that oldnoconfig will be finally removed
- Make 'Selected by:' and 'Implied by' readable in help and
search result
- Hide silentoldconfig from 'make help' to stop confusing people
- Fix misc things and cleanups
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Merge tag 'kconfig-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kconfig updates from Masahiro Yamada:
"A pretty big batch of Kconfig updates.
I have to mention the lexer and parser of Kconfig are now built from
real .l and .y sources. So, flex and bison are the requirement for
building the kernel. Both of them (unlike gperf) have been stable for
a long time. This change has been tested several weeks in linux-next,
and I did not receive any problem report about this.
Summary:
- add checks for mistakes, like the choice default is not in choice,
help is doubled
- document data structure and complex code
- fix various memory leaks
- change Makefile to build lexer and parser instead of using
pre-generated C files
- drop 'boolean' keyword, which is equivalent to 'bool'
- use default 'yy' prefix and remove unneeded Make variables
- fix gettext() check for xconfig
- announce that oldnoconfig will be finally removed
- make 'Selected by:' and 'Implied by' readable in help and search
result
- hide silentoldconfig from 'make help' to stop confusing people
- fix misc things and cleanups"
* tag 'kconfig-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (37 commits)
kconfig: Remove silentoldconfig from help and docs; fix kconfig/conf's help
kconfig: make "Selected by:" and "Implied by:" readable
kconfig: announce removal of oldnoconfig if used
kconfig: fix make xconfig when gettext is missing
kconfig: Clarify menu and 'if' dependency propagation
kconfig: Document 'if' flattening logic
kconfig: Clarify choice dependency propagation
kconfig: Document SYMBOL_OPTIONAL logic
kbuild: remove unnecessary LEX_PREFIX and YACC_PREFIX
kconfig: use default 'yy' prefix for lexer and parser
kconfig: make conf_unsaved a local variable of conf_read()
kconfig: make xfgets() really static
kconfig: make input_mode static
kconfig: Warn if there is more than one help text
kconfig: drop 'boolean' keyword
kconfig: use bool instead of boolean for type definition attributes, again
kconfig: Remove menu_end_entry()
kconfig: Document important expression functions
kconfig: Document automatic submenu creation code
kconfig: Fix choice symbol expression leak
...
- fix cross-compilation for architectures that setup CROSS_COMPILE
in their arch Makefile
- fix Kconfig rational operators for bool / tristate
- drop a gperf-generated file from .gitignore
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Merge tag 'kbuild-fixes-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild fixes from Masahiro Yamada:
- fix cross-compilation for architectures that setup CROSS_COMPILE in
their arch Makefile
- fix Kconfig rational operators for bool / tristate
- drop a gperf-generated file from .gitignore
* tag 'kbuild-fixes-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
genksyms: drop *.hash.c from .gitignore
kconfig: fix relational operators for bool and tristate symbols
kbuild: move cc-option and cc-disable-warning after incl. arch Makefile
It appears that hardened gentoo enables "-fstack-check" by default for
gcc.
That doesn't work _at_all_ for the kernel, because the kernel stack
doesn't act like a user stack at all: it's much smaller, and it doesn't
auto-expand on use. So the extra "probe one page below the stack" code
generated by -fstack-check just breaks the kernel in horrible ways,
causing infinite double faults etc.
[ I have to say, that the particular code gcc generates looks very
stupid even for user space where it works, but that's a separate
issue. ]
Reported-and-tested-by: Alexander Tsoy <alexander@tsoy.me>
Reported-and-tested-by: Toralf Förster <toralf.foerster@gmx.de>
Cc: stable@kernel.org
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Allow users to use their favorite lexer / parser generators.
This is useful for me to test various flex and bison versions.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Geert reported commit ae6b289a37 ("kbuild: Set KBUILD_CFLAGS before
incl. arch Makefile") broke cross-compilation using a cross-compiler
that supports less compiler options than the host compiler.
For example,
cc1: error: unrecognized command line option "-Wno-unused-but-set-variable"
This problem happens on architectures that setup CROSS_COMPILE in their
arch/*/Makefile.
Move the cc-option and cc-disable-warning back to the original position,
but keep the Clang target options untouched.
Fixes: ae6b289a37 ("kbuild: Set KBUILD_CFLAGS before incl. arch Makefile")
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
The "rpm" has been kept for backward compatibility since pre-git era.
I am planning to remove it after the Linux 4.18 release. Annouce the
end of the support, prompting to use "rpm-pkg" instead.
If you use "rpm", it will work like "rpm-pkg", but warning messages
will be displayed as follows:
WARNING: "rpm" target will be removed after Linux 4.18
Please use "rpm-pkg" instead.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Set the clang KBUILD_CFLAGS up before including arch/ Makefiles,
so that ld-options (etc.) can work correctly.
This fixes errors with clang such as ld-options trying to CC
against your host architecture, but LD trying to link against
your target architecture.
Signed-off-by: Chris Fries <cfries@google.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Tested-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
"obj-y += foo/" syntax requires Kbuild to visit the "foo" subdirectory
and link built-in.o from that directory. This means foo/Makefile is
responsible for creating built-in.o even if there is no object to
link (in this case, built-in.o is an empty archive).
We have had several fixups like commit 4b024242e8 ("kbuild: Fix
linking error built-in.o no such file or directory"), then ended up
with a complex condition as follows:
ifneq ($(strip $(obj-y) $(obj-m) $(obj-) $(subdir-m) $(lib-target)),)
builtin-target := $(obj)/built-in.o
endif
We still have more cases not covered by the above, so we need to add
obj- := dummy.o
in several places just for creating empty built-in.o.
A key point is, the parent Makefile knows whether built-in.o is needed
or not. If a subdirectory needs to create built-in.o, its parent can
tell the fact when descending.
If non-empty $(need-builtin) flag is passed from the parent, built-in.o
should be created. $(obj-y) should be still checked to support the
single target "%/". All of ugly tricks will go away.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Most places use pwd and rely on $PATH lookup. Moving the remaining
absolute path /bin/pwd users over for consistency.
Also, a reason for doing /bin/pwd -> pwd instead of the other way around
is because I believe build systems should make little assumptions on
host filesystem layout. Case in point, we do this kind of patching
already in NixOS.
Ref. commit 028568d84d
("kbuild: revert $(realpath ...) to $(shell cd ... && /bin/pwd)").
Signed-off-by: Bjørn Forsman <bjorn.forsman@gmail.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
One of the most remarkable improvements in this cycle is, Kbuild is
now able to cache the result of shell commands. Some variables are
expensive to compute, for example, $(call cc-option,...) invokes the
compiler. It is not efficient to redo this computation every time,
even when we are not actually building anything. Kbuild creates a
hidden file ".cache.mk" that contains invoked shell commands and
their results. The speed-up should be noticeable.
Summary:
- Fix arch build issues (hexagon, sh)
- Clean up various Makefiles and scripts
- Fix wrong usage of {CFLAGS,LDFLAGS}_MODULE in arch Makefiles
- Cache variables that are expensive to compute
- Improve cc-ldopton and ld-option for Clang
- Optimize output directory creation
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Merge tag 'kbuild-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:
"One of the most remarkable improvements in this cycle is, Kbuild is
now able to cache the result of shell commands. Some variables are
expensive to compute, for example, $(call cc-option,...) invokes the
compiler. It is not efficient to redo this computation every time,
even when we are not actually building anything. Kbuild creates a
hidden file ".cache.mk" that contains invoked shell commands and their
results. The speed-up should be noticeable.
Summary:
- Fix arch build issues (hexagon, sh)
- Clean up various Makefiles and scripts
- Fix wrong usage of {CFLAGS,LDFLAGS}_MODULE in arch Makefiles
- Cache variables that are expensive to compute
- Improve cc-ldopton and ld-option for Clang
- Optimize output directory creation"
* tag 'kbuild-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (30 commits)
kbuild: move coccicheck help from scripts/Makefile.help to top Makefile
sh: decompressor: add shipped files to .gitignore
frv: .gitignore: ignore vmlinux.lds
selinux: remove unnecessary assignment to subdir-
kbuild: specify FORCE in Makefile.headersinst as .PHONY target
kbuild: remove redundant mkdir from ./Kbuild
kbuild: optimize object directory creation for incremental build
kbuild: create object directories simpler and faster
kbuild: filter-out PHONY targets from "targets"
kbuild: remove redundant $(wildcard ...) for cmd_files calculation
kbuild: create directory for make cache only when necessary
sh: select KBUILD_DEFCONFIG depending on ARCH
kbuild: fix linker feature test macros when cross compiling with Clang
kbuild: shrink .cache.mk when it exceeds 1000 lines
kbuild: do not call cc-option before KBUILD_CFLAGS initialization
kbuild: Cache a few more calls to the compiler
kbuild: Add a cache for generated variables
kbuild: add forward declaration of default target to Makefile.asm-generic
kbuild: remove KBUILD_SUBDIR_ASFLAGS and KBUILD_SUBDIR_CCFLAGS
hexagon/kbuild: replace CFLAGS_MODULE with KBUILD_CFLAGS_MODULE
...
The flag enables Clang instrumentation of comparison operations
(currently not supported by GCC). This instrumentation is needed by the
new KCOV device to collect comparison operands.
Link: http://lkml.kernel.org/r/20171011095459.70721-2-glider@google.com
Signed-off-by: Victor Chibotaru <tchibo@google.com>
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Popov <alex.popov@linux.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: <syzkaller@googlegroups.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In my view, it is not helpful to have a separate file just for
the coccicheck help message. Merge scripts/Makefile.help into
the top-level Makefile.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
I do not see any reason why $(wildcard ...) needs to be called twice
for computing cmd_files. Remove the first one.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
This tag contains the core RISC-V Linux port, which has been through
nine rounds of review on various mailing lists. The port is not
complete: there's some cleanup patches moving through the review
process, a whole bunch of drivers that need some work, and a lot of
feature additions that will be needed.
The patches contained in this tag have been through nine rounds of
review on the various mailing lists. I have some outstanding cleanup
patches, but since there's been so much review on these patches I
thought it would be best to submit them as-is and then submit explicit
cleanup patches so everyone can review them. This first patch set is
big enough that it's a bit of a pain to constantly rewrite, and it's
caused a few headaches with various contributors.
The port is definately a work in progress. While what's there builds
and boots with 4.14, it's a bit hard to actually see anything happen
because there are no device drivers yet. I maintain a staging branch
that contains all the device drivers and cleanup that actually works,
but those patches won't all be ready for a while. I'd like to get what
we currently have into your tree so everyone can start working from a
single base -- of particular importance is allowing the glibc
upstreaming process to proceed so we can sort out any possibly lingering
user-visible ABI problems we might have.
Copied below is the ChangeLog that contains the history of this patch
set:
(v9) As per suggestions on our v8 patch set, I've split the core architecture code
out from our drivers and would like to submit this patch set to be included
into linux-next, with the goal being to be merged in during the next merge
window. This patch set is based on 4.14-rc2, but if it's better to have it
based on something else then I can change it around.
This patch set contains just the core arch code for RISC-V, so while it builds
an nominally boots, you can't print or take an interrupt so it's not that
useful. If you're looking to actually boot a system it would probably be
better to use the full patch set listed below.
We've collected a handful of tags from reviewers, and the remainder of the
patch set only got minimal feedback last time. Here's what changed:
* We now use the device tree to initialize the timer driver so it's less
tighly coupled with the arch port.
* I cleaned up the defconfigs -- there's actually now just one, and it's
empty. For now I think we're OK with what the kernel sets as defaults, but
I anticipate we'll begin to expand this as people start to use the port
more.
* The VDSO symbols version is sane.
* We WFI while spinning in the boot loop.
* A handful of comments have been added.
While there are still a handful of FIXMEs in this patch set, we've started to
get enough interest from various users and contributors that maintaining an out
of tree patch set is starting to become a big burden. Hopefully the patches
are good enough to merge now, which will at least get everyone working in a
more reasonable manner as we clean up the remaining issues.
This patch set is also availiable on github
https://github.com/riscv/riscv-linux/tree/riscv-for-submission-v9-arch
as is the entire patch set necessary to get a more functional RISC-V system up
and running, including a handful of patches that aren't ready for upstream yet.
https://github.com/riscv/riscv-linux/tree/riscv-for-submission-v9
Hopefully I've managed to get everyone's feedback
Here's the change highlights from the whole patch set:
(v8) I know it may not be the ideal time to submit a patch set right now, as
it's the middle of the merge window, but things have calmed down quite a bit in
the last month so I thought it would be good to get everyone on the same page.
There's been a handful of changes since the last patch set, but most of them
are fairly minor:
* We changed PAGE_OFFSET to allowing mapping more physical memory on 64-bit
systems. This is user configurable, as it triggers a different code model
that generates slightly less efficient code.
* The device tree binding documentation is back, I'd managed to lose it at some
point.
* We now pass the atomic64 test suite. The SBI timer driver has been
* refactored.
(v7) It's been a while since my last patch set, but the changes han been fairly
minimal:
* The PCI cleanup patches have been dropped, we'll do them as a separate patch
set later.
* We've the Kconfig entries from CONFIG_ISA_* to CONFIG_RISCV_ISA_*, to make
grep easier.
* There have been a handful of memory model related tweaks in I/O land,
particularly relating the PCI and the upcoming platform specification.
There are significant comments in the relevant files. This is still a WIP,
but I think we're close to getting as good as we're going to get until we
end up with some more specifications.
(v6) As it's been only a day since the v5 patch set, the changes are pretty
minimal:
* The patch set is now based on linux-next/master, which I believe is a better
base now that we're getting closer to upstream.
* EARLY_PRINTK is no longer an option. Since the SBI console is reasonable,
there's no penalty to enabling it (and thus no benefit to disabling it).
* The mmap syscalls were refactored a bit.
(v5) Things have really started to calm down, so this is fairly similar to the
v4 patch set. The most interesting changes include:
* We've moved back to a single patch set.
* SMP support has been fixed, I was accidentally running on a non-SMP
configuration. There were various mistakes all over the tree as a result of
this.
* The cmpxchg syscalls have been removed, as they were deemed a bad idea. As
a result, RISC-V Linux systems mandate the A extension. The corresponding
Kconfig entry to enable builds on non-A systems has been removed.
* A few more atomic fixes: mostly fence changes, but those resulted in a
handful of additional macros that were no longer necessary.
* riscv_early_sie has been removed.
(v4) There have only been a few changes since the v3 patch set:
* The cmpxchg64 syscall is no longer enabled on 32-bit systems. It's not
possible to provide this on SMP systems, and it's not necessary as glibc
knows not to call it.
* We provide a ELF_HWCAP so users can determine the ISA of the machine the
kernel is running on.
* The multi-line comments are in a better form.
* There were a handful of headers that could be replaced with the asm-generic
versions, and a few unnecessary definitions.
* We no longer use printk, but instead use pr_*.
* A few Kconfig and defconfig entries have been cleaned up.
(v3) A highlight of the changes since the v2 patch set includes:
* We've split out all our drivers into separate patch sets, which I've already
sent out to the relevant maintainers. I haven't included those patches in
this patch set, but some of them are necessary to build our port. A git
tree that contains all our patch sets merged together lives at
<https://github.com/riscv/riscv-linux/tree/riscv-for-submission-v3>.
* The patch set is now split up differently: rather than being split per
directory it is split per topic. Hopefully this will make it easier to
review the port on the mailing list. The split is a bit rough, so you
probably still want to look at the patch set as a whole.
* atomic.h has been completely rewritten and is hopefully now correct. I've
attempted to sanitize the various other memory model related code as well,
and I think it should all be sane now aside from a handful of FIXMEs
commented in the code.
* We've changed the cmpexchg syscall to always exist and to not be
multiplexed. There is also a VDSO entry for compare and exchange, which
allows kernels with the A extension to execute user code without the A
extension reasonably fast.
* Our user-visible register state now contains enough space for the Q
extension for 128-bit floating point, as well as a few words to allow
extensibility to future ISA extensions like the eventual V extension for
vectors.
* A handful of driver cleanups, but these have been split into separate patch
sets now so I won't duplicate them here.
(v2) A highlight of the changes since the v1 patch set includes:
* We've split out our drivers into the right places, which means now there's
a lot more patches. I'll be submitting these patches to various subsystem
maintainers and including them in any future RISC-V patch sets until
they've been merged.
* The SBI console driver has been completely rewritten to use the HVC helpers
and is now significantly smaller.
* We've begun to use weaker barriers as opposed to just the big "fence".
There's still some work to do here, specifically:
- We need fences in the relaxed MMIO functions.
- The non-relaxed MMIO functions are missing R/W bits on their fences.
- Many AMOs need the aq and rl bits set.
* We now have thread_info in task_struct. As a result, sscratch now contains
TP instead of SP. This was necessary because thread_info is no longer on
the stack.
* A few shared routines have been added that we use instead of creating
another arch copy.
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Merge tag 'riscv-for-linus-4.15-arch-v9-premerge' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/linux
Pull RISC-V architecture support from Palmer Dabbelt:
"This contains the core RISC-V Linux port, which has been through nine
rounds of review on various mailing lists. The port is not complete:
there's some cleanup patches moving through the review process, a
whole bunch of drivers that need some work, and a lot of feature
additions that will be needed.
The patches contained in this tag have been through nine rounds of
review on the various mailing lists. I have some outstanding cleanup
patches, but since there's been so much review on these patches I
thought it would be best to submit them as-is and then submit explicit
cleanup patches so everyone can review them. This first patch set is
big enough that it's a bit of a pain to constantly rewrite, and it's
caused a few headaches with various contributors.
The port is definately a work in progress. While what's there builds
and boots with 4.14, it's a bit hard to actually see anything happen
because there are no device drivers yet. I maintain a staging branch
that contains all the device drivers and cleanup that actually works,
but those patches won't all be ready for a while. I'd like to get what
we currently have into your tree so everyone can start working from a
single base -- of particular importance is allowing the glibc
upstreaming process to proceed so we can sort out any possibly
lingering user-visible ABI problems we might have.
Copied below is the ChangeLog that contains the history of this patch
set:
(v9) As per suggestions on our v8 patch set, I've split the core
architecture code out from our drivers and would like to submit
this patch set to be included into linux-next, with the goal
being to be merged in during the next merge window. This patch
set is based on 4.14-rc2, but if it's better to have it based on
something else then I can change it around.
This patch set contains just the core arch code for RISC-V, so
while it builds an nominally boots, you can't print or take an
interrupt so it's not that useful. If you're looking to actually
boot a system it would probably be better to use the full patch
set listed below.
We've collected a handful of tags from reviewers, and the
remainder of the patch set only got minimal feedback last time.
Here's what changed:
- We now use the device tree to initialize the timer driver so
it's less tighly coupled with the arch port.
- I cleaned up the defconfigs -- there's actually now just one,
and it's empty. For now I think we're OK with what the kernel
sets as defaults, but I anticipate we'll begin to expand this
as people start to use the port more.
- The VDSO symbols version is sane.
- We WFI while spinning in the boot loop.
- A handful of comments have been added.
While there are still a handful of FIXMEs in this patch set,
we've started to get enough interest from various users and
contributors that maintaining an out of tree patch set is
starting to become a big burden. Hopefully the patches are good
enough to merge now, which will at least get everyone working in
a more reasonable manner as we clean up the remaining issues.
(v8) I know it may not be the ideal time to submit a patch set right
now, as it's the middle of the merge window, but things have
calmed down quite a bit in the last month so I thought it would
be good to get everyone on the same page. There's been a handful
of changes since the last patch set, but most of them are fairly
minor:
- We changed PAGE_OFFSET to allowing mapping more physical
memory on 64-bit systems. This is user configurable, as it
triggers a different code model that generates slightly less
efficient code.
- The device tree binding documentation is back, I'd managed to
lose it at some point.
- We now pass the atomic64 test suite
- The SBI timer driver has been refactored.
(v7) It's been a while since my last patch set, but the changes han
been fairly minimal:
- The PCI cleanup patches have been dropped, we'll do them as a
separate patch set later.
- We've the Kconfig entries from CONFIG_ISA_* to
CONFIG_RISCV_ISA_*, to make grep easier.
- There have been a handful of memory model related tweaks in
I/O land, particularly relating the PCI and the upcoming
platform specification. There are significant comments in the
relevant files. This is still a WIP, but I think we're close
to getting as good as we're going to get until we end up with
some more specifications.
(v6) As it's been only a day since the v5 patch set, the changes are
pretty minimal:
- The patch set is now based on linux-next/master, which I
believe is a better base now that we're getting closer to
upstream.
- EARLY_PRINTK is no longer an option. Since the SBI console is
reasonable, there's no penalty to enabling it (and thus no
benefit to disabling it).
- The mmap syscalls were refactored a bit.
(v5) Things have really started to calm down, so this is fairly
similar to the v4 patch set. The most interesting changes
include:
- We've moved back to a single patch set.
- SMP support has been fixed, I was accidentally running on a
non-SMP configuration. There were various mistakes all over
the tree as a result of this.
- The cmpxchg syscalls have been removed, as they were deemed a
bad idea. As a result, RISC-V Linux systems mandate the A
extension. The corresponding Kconfig entry to enable builds
on non-A systems has been removed.
- A few more atomic fixes: mostly fence changes, but those
resulted in a handful of additional macros that were no
longer necessary.
- riscv_early_sie has been removed.
(v4) There have only been a few changes since the v3 patch set:
- The cmpxchg64 syscall is no longer enabled on 32-bit systems.
It's not possible to provide this on SMP systems, and it's
not necessary as glibc knows not to call it.
- We provide a ELF_HWCAP so users can determine the ISA of the
machine the kernel is running on.
- The multi-line comments are in a better form.
- There were a handful of headers that could be replaced with
the asm-generic versions, and a few unnecessary definitions.
- We no longer use printk, but instead use pr_*.
- A few Kconfig and defconfig entries have been cleaned up.
(v3) A highlight of the changes since the v2 patch set includes:
- We've split out all our drivers into separate patch sets,
which I've already sent out to the relevant maintainers. I
haven't included those patches in this patch set, but some of
them are necessary to build our port.
- The patch set is now split up differently: rather than being
split per directory it is split per topic. Hopefully this
will make it easier to review the port on the mailing list.
The split is a bit rough, so you probably still want to look
at the patch set as a whole.
- atomic.h has been completely rewritten and is hopefully now
correct. I've attempted to sanitize the various other memory
model related code as well, and I think it should all be sane
now aside from a handful of FIXMEs commented in the code.
- We've changed the cmpexchg syscall to always exist and to not
be multiplexed. There is also a VDSO entry for compare and
exchange, which allows kernels with the A extension to
execute user code without the A extension reasonably fast.
- Our user-visible register state now contains enough space for
the Q extension for 128-bit floating point, as well as a few
words to allow extensibility to future ISA extensions like
the eventual V extension for vectors.
- A handful of driver cleanups, but these have been split into
separate patch sets now so I won't duplicate them here.
(v2) A highlight of the changes since the v1 patch set includes:
- We've split out our drivers into the right places, which
means now there's a lot more patches. I'll be submitting
these patches to various subsystem maintainers and including
them in any future RISC-V patch sets until they've been
merged.
- The SBI console driver has been completely rewritten to use
the HVC helpers and is now significantly smaller.
- We've begun to use weaker barriers as opposed to just the big
"fence". There's still some work to do here, specifically:
- We need fences in the relaxed MMIO functions.
- The non-relaxed MMIO functions are missing R/W bits on their fences.
- Many AMOs need the aq and rl bits set.
- We now have thread_info in task_struct. As a result, sscratch
now contains TP instead of SP. This was necessary because
thread_info is no longer on the stack.
- A few shared routines have been added that we use instead of
creating another arch copy"
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
* tag 'riscv-for-linus-4.15-arch-v9-premerge' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/linux:
RISC-V: Build Infrastructure
RISC-V: User-facing API
RISC-V: Paging and MMU
RISC-V: Device, timer, IRQs, and the SBI
RISC-V: Task implementation
RISC-V: ELF and module implementation
RISC-V: Generic library routines and assembly
RISC-V: Atomic and Locking Code
RISC-V: Init and Halt Code
dt-bindings: RISC-V CPU Bindings
lib: Add shared copies of some GCC library routines
MAINTAINERS: Add RISC-V
- kbuild cleanups and improvements for dtbs
- Code clean-up of overlay code and fixing for some long standing memory
leak and race condition in applying overlays
- Improvements to DT memory usage making sysfs/kobjects optional and
skipping unflattening of disabled nodes. This is part of kernel
tinification efforts.
- Final piece of removing storing the full path for every DT node. The
prerequisite conversion of printk's to use device_node format
specifier happened in 4.14.
- Sync with current upstream dtc. This brings additional checks to dtb
compiling.
- Binding doc tree wide removal of leading 0s from examples
- RTC binding documentation adding missing devices and some
consolidation of duplicated bindings
- Vendor prefix documentation for nutsboard, Silicon Storage Technology,
shimafuji, Tecon Microprocessor Technologies, DH electronics GmbH,
Opal Kelly, and Next Thing
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Merge tag 'devicetree-for-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux
Pull DeviceTree updates from Rob Herring:
"A bigger diffstat than usual with the kbuild changes and a tree wide
fix in the binding documentation.
Summary:
- kbuild cleanups and improvements for dtbs
- Code clean-up of overlay code and fixing for some long standing
memory leak and race condition in applying overlays
- Improvements to DT memory usage making sysfs/kobjects optional and
skipping unflattening of disabled nodes. This is part of kernel
tinification efforts.
- Final piece of removing storing the full path for every DT node.
The prerequisite conversion of printk's to use device_node format
specifier happened in 4.14.
- Sync with current upstream dtc. This brings additional checks to
dtb compiling.
- Binding doc tree wide removal of leading 0s from examples
- RTC binding documentation adding missing devices and some
consolidation of duplicated bindings
- Vendor prefix documentation for nutsboard, Silicon Storage
Technology, shimafuji, Tecon Microprocessor Technologies, DH
electronics GmbH, Opal Kelly, and Next Thing"
* tag 'devicetree-for-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (55 commits)
dt-bindings: usb: add #phy-cells to usb-nop-xceiv
dt-bindings: Remove leading zeros from bindings notation
kbuild: handle dtb-y and CONFIG_OF_ALL_DTBS natively in Makefile.lib
MIPS: dts: remove bogus bcm96358nb4ser.dtb from dtb-y entry
kbuild: clean up *.dtb and *.dtb.S patterns from top-level Makefile
.gitignore: move *.dtb and *.dtb.S patterns to the top-level .gitignore
.gitignore: sort normal pattern rules alphabetically
dt-bindings: add vendor prefix for Next Thing Co.
scripts/dtc: Update to upstream version v1.4.5-6-gc1e55a5513e9
of: dynamic: fix memory leak related to properties of __of_node_dup
of: overlay: make pr_err() string unique
of: overlay: pr_err from return NOTIFY_OK to overlay apply/remove
of: overlay: remove unneeded check for NULL kbasename()
of: overlay: remove a dependency on device node full_name
of: overlay: simplify applying symbols from an overlay
of: overlay: avoid race condition between applying multiple overlays
of: overlay: loosen overly strict phandle clash check
of: overlay: expand check of whether overlay changeset can be removed
of: overlay: detect cases where device tree may become corrupt
of: overlay: minor restructuring
...
Pull x86 core updates from Ingo Molnar:
"Note that in this cycle most of the x86 topics interacted at a level
that caused them to be merged into tip:x86/asm - but this should be a
temporary phenomenon, hopefully we'll back to the usual patterns in
the next merge window.
The main changes in this cycle were:
Hardware enablement:
- Add support for the Intel UMIP (User Mode Instruction Prevention)
CPU feature. This is a security feature that disables certain
instructions such as SGDT, SLDT, SIDT, SMSW and STR. (Ricardo Neri)
[ Note that this is disabled by default for now, there are some
smaller enhancements in the pipeline that I'll follow up with in
the next 1-2 days, which allows this to be enabled by default.]
- Add support for the AMD SEV (Secure Encrypted Virtualization) CPU
feature, on top of SME (Secure Memory Encryption) support that was
added in v4.14. (Tom Lendacky, Brijesh Singh)
- Enable new SSE/AVX/AVX512 CPU features: AVX512_VBMI2, GFNI, VAES,
VPCLMULQDQ, AVX512_VNNI, AVX512_BITALG. (Gayatri Kammela)
Other changes:
- A big series of entry code simplifications and enhancements (Andy
Lutomirski)
- Make the ORC unwinder default on x86 and various objtool
enhancements. (Josh Poimboeuf)
- 5-level paging enhancements (Kirill A. Shutemov)
- Micro-optimize the entry code a bit (Borislav Petkov)
- Improve the handling of interdependent CPU features in the early
FPU init code (Andi Kleen)
- Build system enhancements (Changbin Du, Masahiro Yamada)
- ... plus misc enhancements, fixes and cleanups"
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (118 commits)
x86/build: Make the boot image generation less verbose
selftests/x86: Add tests for the STR and SLDT instructions
selftests/x86: Add tests for User-Mode Instruction Prevention
x86/traps: Fix up general protection faults caused by UMIP
x86/umip: Enable User-Mode Instruction Prevention at runtime
x86/umip: Force a page fault when unable to copy emulated result to user
x86/umip: Add emulation code for UMIP instructions
x86/cpufeature: Add User-Mode Instruction Prevention definitions
x86/insn-eval: Add support to resolve 16-bit address encodings
x86/insn-eval: Handle 32-bit address encodings in virtual-8086 mode
x86/insn-eval: Add wrapper function for 32 and 64-bit addresses
x86/insn-eval: Add support to resolve 32-bit address encodings
x86/insn-eval: Compute linear address in several utility functions
resource: Fix resource_size.cocci warnings
X86/KVM: Clear encryption attribute when SEV is active
X86/KVM: Decrypt shared per-cpu variables when SEV is active
percpu: Introduce DEFINE_PER_CPU_DECRYPTED
x86: Add support for changing memory encryption attribute in early boot
x86/io: Unroll string I/O when SEV is active
x86/boot: Add early boot support when running with SEV active
...
- The old driver statement has been added to the kernel docs.
- We have a couple of new helper scripts. find-unused-docs.sh from Sayli
Karnic will point out kerneldoc comments that are not actually used in
the documentation. Jani Nikula's documentation-file-ref-check finds
references to non-existing files.
- A new ftrace document from Steve Rostedt.
- Vinod Koul converted the dmaengine docs to RST
Beyond that, it's mostly simple fixes.
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Merge tag 'docs-4.15' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
"A relatively calm cycle for the docs tree again.
- The old driver statement has been added to the kernel docs.
- We have a couple of new helper scripts. find-unused-docs.sh from
Sayli Karnic will point out kerneldoc comments that are not actually
used in the documentation. Jani Nikula's
documentation-file-ref-check finds references to non-existing files.
- A new ftrace document from Steve Rostedt.
- Vinod Koul converted the dmaengine docs to RST
Beyond that, it's mostly simple fixes.
This set reaches outside of Documentation/ a bit more than most. In
all cases, the changes are to comment docs, mostly from Randy, in
places where there didn't seem to be anybody better to take them"
* tag 'docs-4.15' of git://git.lwn.net/linux: (52 commits)
documentation: fb: update list of available compiled-in fonts
MAINTAINERS: update DMAengine documentation location
dmaengine: doc: ReSTize pxa_dma doc
dmaengine: doc: ReSTize dmatest doc
dmaengine: doc: ReSTize client API doc
dmaengine: doc: ReSTize provider doc
dmaengine: doc: Add ReST style dmaengine document
ftrace/docs: Add documentation on how to use ftrace from within the kernel
bug-hunting.rst: Fix an example and a typo in a Sphinx tag
scripts: Add a script to find unused documentation
samples: Convert timers to use timer_setup()
documentation: kernel-api: add more info on bitmap functions
Documentation: fix selftests related file refs
Documentation: fix ref to power basic-pm-debugging
Documentation: fix ref to trace stm content
Documentation: fix ref to coccinelle content
Documentation: fix ref to workqueue content
Documentation: fix ref to sphinx/kerneldoc.py
Documentation: fix locking rt-mutex doc refs
docs: dev-tools: correct Coccinelle version number
...
Some $(call cc-option,...) are invoked very early, even before
KBUILD_CFLAGS, etc. are initialized.
The returned string from $(call cc-option,...) depends on
KBUILD_CPPFLAGS, KBUILD_CFLAGS, and GCC_PLUGINS_CFLAGS.
Since they are exported, they are not empty when the top Makefile
is recursively invoked.
The recursion occurs in several places. For example, the top
Makefile invokes itself for silentoldconfig. "make tinyconfig",
"make rpm-pkg" are the cases, too.
In those cases, the second call of cc-option from the same line
runs a different shell command due to non-pristine KBUILD_CFLAGS.
To get the same result all the time, KBUILD_* and GCC_PLUGINS_CFLAGS
must be initialized before any call of cc-option. This avoids
garbage data in the .cache.mk file.
Move all calls of cc-option below the config targets because target
compiler flags are unnecessary for Kconfig.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
These are a few stragglers that I left out of the original patch to
cache calls to the C compiler ("kbuild: Add a cache for generated
variables") because they bleed out into the main Makefile and thus
uglify things a little bit. The idea is the same here, though.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
While timing a "no-op" build of the kernel (incrementally building the
kernel even though nothing changed) in the Chrome OS build system I
found that it was much slower than I expected.
Digging into things a bit, I found that quite a bit of the time was
spent invoking the C compiler even though we weren't actually building
anything. Currently in the Chrome OS build system the C compiler is
called through a number of wrappers (one of which is written in
python!) and can take upwards of 100 ms to invoke even if we're not
doing anything difficult, so these invocations of the compiler were
taking a lot of time. Worse the invocations couldn't seem to take
advantage of the multiple cores on my system.
Certainly it seems like we could make the compiler invocations in the
Chrome OS build system faster, but only to a point. Inherently
invoking a program as big as a C compiler is a fairly heavy
operation. Thus even if we can speed the compiler calls it made sense
to track down what was happening.
It turned out that all the compiler invocations were coming from
usages like this in the kernel's Makefile:
KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks,)
Due to the way cc-option and similar statements work the above
contains an implicit call to the C compiler. ...and due to the fact
that we're storing the result in KBUILD_CFLAGS, a simply expanded
variable, the call will happen every time the Makefile is parsed, even
if there are no users of KBUILD_CFLAGS.
Rather than redoing this computation every time, it makes a lot of
sense to cache the result of all of the Makefile's compiler calls just
like we do when we compile a ".c" file to a ".o" file. Conceptually
this is quite a simple idea. ...and since the calls to invoke the
compiler and similar tools are centrally located in the Kbuild.include
file this doesn't even need to be super invasive.
Implementing the cache in a simple-to-use and efficient way is not
quite as simple as it first sounds, though. To get maximum speed we
really want the cache in a format that make can natively understand
and make doesn't really have an ability to load/parse files. ...but
make _can_ import other Makefiles, so the solution is to store the
cache in Makefile format. This requires coming up with a valid/unique
Makefile variable name for each value to be cached, but that's
solvable with some cleverness.
After this change, we'll automatically create a ".cache.mk" file that
will contain our cached variables. We'll load this on each invocation
of make and will avoid recomputing anything that's already in our
cache. The cache is stored in a format that it shouldn't need any
invalidation since anything that might change should affect the "key"
and any old cached value won't be used.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
We need to add "clean-files" in Makfiles to clean up DT blobs, but we
often miss to do so.
Since there are no source files that end with .dtb or .dtb.S, so we
can clean-up those files from the top-level Makefile.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Rob Herring <robh@kernel.org>