24 Aug, 2018
3 commits
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Merge fixes for missing TLB shootdowns.
This fixes a couple of cases that involved us possibly freeing page
table structures before the required TLB shootdown had been done.There are a few cleanup patches to make the code easier to follow, and
to avoid some of the more problematic cases entirely when not necessary.To make this easier for backports, it undoes the recent lazy TLB
patches, because the cleanups and fixes are more important, and Rik is
ok with re-doing them later when things have calmed down.The missing TLB flush was only delayed, and the wrong ordering only
happened under memory pressure (and in theory under a couple of other
fairly theoretical situations), so this may have been all very unlikely
to have hit people in practice.But getting the TLB shootdown wrong is _so_ hard to debug and see that I
consider this a crticial fix.Many thanks to Jann Horn for having debugged this.
* tlb-fixes:
x86/mm: Only use tlb_remove_table() for paravirt
mm: mmu_notifier fix for tlb_end_vma
mm/tlb, x86/mm: Support invalidating TLB caches for RCU_TABLE_FREE
mm/tlb: Remove tlb_remove_table() non-concurrent condition
mm: move tlb_table_flush to tlb_flush_mmu_free
x86/mm/tlb: Revert the recent lazy TLB patches -
Pull MIPS fixes from Paul Burton:
- Fix microMIPS build failures by adding a .insn directive to the
barrier_before_unreachable() asm statement in order to convince the
toolchain that the asm statement is a valid branch target rather
than a bogus attempt to switch ISA.- Clean up our declarations of TLB functions that we overwrite with
generated code in order to prevent the compiler making assumptions
about alignment that cause microMIPS kernels built with GCC 7 &
above to die early during boot.- Fix up a regression for MIPS32 kernels which slipped into the main
MIPS pull for 4.19, causing CONFIG_32BIT=y kernels to contain
inappropriate MIPS64 instructions.- Extend our existing workaround for MIPSr6 builds that end up using
the __multi3 intrinsic to GCC 7 & below, rather than just GCC 7.* tag 'mips_4.19_2' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
MIPS: lib: Provide MIPS64r6 __multi3() for GCC < 7
MIPS: Workaround GCC __builtin_unreachable reordering bug
compiler.h: Allow arch-specific asm/compiler.h
MIPS: Avoid move psuedo-instruction whilst using MIPS_ISA_LEVEL
MIPS: Consistently declare TLB functions
MIPS: Export tlbmiss_handler_setup_pgd near its definition -
Jann reported that x86 was missing required TLB invalidates when he
hit the !*batch slow path in tlb_remove_table().This is indeed the case; RCU_TABLE_FREE does not provide TLB (cache)
invalidates, the PowerPC-hash where this code originated and the
Sparc-hash where this was subsequently used did not need that. ARM
which later used this put an explicit TLB invalidate in their
__p*_free_tlb() functions, and PowerPC-radix followed that example.But when we hooked up x86 we failed to consider this. Fix this by
(optionally) hooking tlb_remove_table() into the TLB invalidate code.NOTE: s390 was also needing something like this and might now
be able to use the generic code again.[ Modified to be on top of Nick's cleanups, which simplified this patch
now that tlb_flush_mmu_tlbonly() really only flushes the TLB - Linus ]Fixes: 9e52fc2b50de ("x86/mm: Enable RCU based page table freeing (CONFIG_HAVE_RCU_TABLE_FREE=y)")
Reported-by: Jann Horn
Signed-off-by: Peter Zijlstra (Intel)
Acked-by: Rik van Riel
Cc: Nicholas Piggin
Cc: David Miller
Cc: Will Deacon
Cc: Martin Schwidefsky
Cc: Michael Ellerman
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds
23 Aug, 2018
1 commit
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Patch series "add support for relative references in special sections", v10.
This adds support for emitting special sections such as initcall arrays,
PCI fixups and tracepoints as relative references rather than absolute
references. This reduces the size by 50% on 64-bit architectures, but
more importantly, it removes the need for carrying relocation metadata for
these sections in relocatable kernels (e.g., for KASLR) that needs to be
fixed up at boot time. On arm64, this reduces the vmlinux footprint of
such a reference by 8x (8 byte absolute reference + 24 byte RELA entry vs
4 byte relative reference)Patch #3 was sent out before as a single patch. This series supersedes
the previous submission. This version makes relative ksymtab entries
dependent on the new Kconfig symbol HAVE_ARCH_PREL32_RELOCATIONS rather
than trying to infer from kbuild test robot replies for which
architectures it should be blacklisted.Patch #1 introduces the new Kconfig symbol HAVE_ARCH_PREL32_RELOCATIONS,
and sets it for the main architectures that are expected to benefit the
most from this feature, i.e., 64-bit architectures or ones that use
runtime relocations.Patch #2 add support for #define'ing __DISABLE_EXPORTS to get rid of
ksymtab/kcrctab sections in decompressor and EFI stub objects when
rebuilding existing C files to run in a different context.Patches #4 - #6 implement relative references for initcalls, PCI fixups
and tracepoints, respectively, all of which produce sections with order
~1000 entries on an arm64 defconfig kernel with tracing enabled. This
means we save about 28 KB of vmlinux space for each of these patches.[From the v7 series blurb, which included the jump_label patches as well]:
For the arm64 kernel, all patches combined reduce the memory footprint
of vmlinux by about 1.3 MB (using a config copied from Ubuntu that has
KASLR enabled), of which ~1 MB is the size reduction of the RELA section
in .init, and the remaining 300 KB is reduction of .text/.data.This patch (of 6):
Before updating certain subsystems to use place relative 32-bit
relocations in special sections, to save space and reduce the number of
absolute relocations that need to be processed at runtime by relocatable
kernels, introduce the Kconfig symbol and define it for some architectures
that should be able to support and benefit from it.Link: http://lkml.kernel.org/r/20180704083651.24360-2-ard.biesheuvel@linaro.org
Signed-off-by: Ard Biesheuvel
Acked-by: Michael Ellerman
Reviewed-by: Will Deacon
Acked-by: Ingo Molnar
Cc: Arnd Bergmann
Cc: Kees Cook
Cc: Thomas Garnier
Cc: Thomas Gleixner
Cc: "Serge E. Hallyn"
Cc: Bjorn Helgaas
Cc: Benjamin Herrenschmidt
Cc: Russell King
Cc: Paul Mackerras
Cc: Catalin Marinas
Cc: Petr Mladek
Cc: James Morris
Cc: Nicolas Pitre
Cc: Josh Poimboeuf
Cc: Steven Rostedt
Cc: Sergey Senozhatsky ,
Cc: James Morris
Cc: Jessica Yu
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
22 Aug, 2018
1 commit
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We have a need to override the definition of
barrier_before_unreachable() for MIPS, which means we either need to add
architecture-specific code into linux/compiler-gcc.h or we need to allow
the architecture to provide a header that can define the macro before
the generic definition. The latter seems like the better approach.A straightforward approach to the per-arch header is to make use of
asm-generic to provide a default empty header & adjust architectures
which don't need anything specific to make use of that by adding the
header to generic-y. Unfortunately this doesn't work so well due to
commit 28128c61e08e ("kconfig.h: Include compiler types to avoid missed
struct attributes") which caused linux/compiler_types.h to be included
in the compilation of every C file via the -include linux/kconfig.h flag
in c_flags.Because the -include flag is present for all C files we compile, we need
the architecture-provided header to be present before any C files are
compiled. If any C files can be compiled prior to the asm-generic header
wrappers being generated then we hit a build failure due to missing
header. Such cases do exist - one pointed out by the kbuild test robot
is the compilation of arch/ia64/kernel/nr-irqs.c, which occurs as part
of the archprepare target [1].This leaves us with a few options:
1) Use generic-y & fix any build failures we find by enforcing
ordering such that the asm-generic target occurs before any C
compilation, such that linux/compiler_types.h can always include
the generated asm-generic wrapper which in turn includes the empty
asm-generic header. This would rely on us finding all the
problematic cases - I don't know for sure that the ia64 issue is
the only one.2) Add an actual empty header to each architecture, so that we don't
need the generated asm-generic wrapper. This seems messy.3) Give up & add #ifdef CONFIG_MIPS or similar to
linux/compiler_types.h. This seems messy too.4) Include the arch header only when it's actually needed, removing
the need for the asm-generic wrapper for all other architectures.This patch allows us to use approach 4, by including an asm/compiler.h
header from linux/compiler_types.h after the inclusion of the
compiler-specific linux/compiler-*.h header(s). We do this
conditionally, only when CONFIG_HAVE_ARCH_COMPILER_H is selected, in
order to avoid the need for asm-generic wrappers & the associated build
ordering issue described above. The asm/compiler.h header is included
after the generic linux/compiler-*.h header(s) for consistency with the
way linux/compiler-intel.h & linux/compiler-clang.h are included after
the linux/compiler-gcc.h header that they override.[1] https://lists.01.org/pipermail/kbuild-all/2018-August/051175.html
Signed-off-by: Paul Burton
Reviewed-by: Masahiro Yamada
Patchwork: https://patchwork.linux-mips.org/patch/20269/
Cc: Arnd Bergmann
Cc: James Hogan
Cc: Masahiro Yamada
Cc: Ralf Baechle
Cc: linux-arch@vger.kernel.org
Cc: linux-kbuild@vger.kernel.org
Cc: linux-mips@linux-mips.org
16 Aug, 2018
2 commits
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Pull Kconfig consolidation from Masahiro Yamada:
"Consolidation of Kconfig files by Christoph Hellwig.Move the source statements of arch-independent Kconfig files instead
of duplicating the includes in every arch/$(SRCARCH)/Kconfig"* tag 'kconfig-v4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kconfig: add a Memory Management options" menu
kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt
kconfig: use a menu in arch/Kconfig to reduce clutter
kconfig: include kernel/Kconfig.preempt from init/Kconfig
Kconfig: consolidate the "Kernel hacking" menu
kconfig: include common Kconfig files from top-level Kconfig
kconfig: remove duplicate SWAP symbol defintions
um: create a proper drivers Kconfig
um: cleanup Kconfig files
um: stop abusing KBUILD_KCONFIG -
Pull gcc plugin cleanups from Kees Cook:
- Kconfig and Makefile clean-ups (Masahiro Yamada, Kees Cook)
- gcc-common.h definition clean-ups (Alexander Popov)
* tag 'gcc-plugin-cleanup-v4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
gcc-plugins: Clean up the cgraph_create_edge* macros
gcc-plugins: Regularize Makefile.gcc-plugins
gcc-plugins: split out Kconfig entries to scripts/gcc-plugins/Kconfig
gcc-plugins: remove unused GCC_PLUGIN_SUBDIR
02 Aug, 2018
3 commits
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Put everything in arch/Kconfig into a General options menu
so that they don't clutter up the main/major/primary list of
menu options.Signed-off-by: Randy Dunlap
Signed-off-by: Christoph Hellwig
Signed-off-by: Masahiro Yamada -
Almost all architectures include it. Add a ARCH_NO_PREEMPT symbol to
disable preempt support for alpha, hexagon, non-coldfire m68k and
user mode Linux.Signed-off-by: Christoph Hellwig
Signed-off-by: Masahiro Yamada -
Instead of duplicating the source statements in every architecture just
do it once in the toplevel Kconfig file.Note that with this the inclusion of arch/$(SRCARCH/Kconfig moves out of
the top-level Kconfig into arch/Kconfig so that don't violate ordering
constraits while keeping a sensible menu structure.Signed-off-by: Christoph Hellwig
Signed-off-by: Masahiro Yamada
25 Jul, 2018
1 commit
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Collect relevant code into the scripts/gcc-plugins directory.
Signed-off-by: Masahiro Yamada
Signed-off-by: Kees Cook
21 Jun, 2018
1 commit
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Provide a command line and a sysfs knob to control SMT.
The command line options are:
'nosmt': Enumerate secondary threads, but do not online them
'nosmt=force': Ignore secondary threads completely during enumeration
via MP table and ACPI/MADT.The sysfs control file has the following states (read/write):
'on': SMT is enabled. Secondary threads can be freely onlined
'off': SMT is disabled. Secondary threads, even if enumerated
cannot be onlined
'forceoff': SMT is permanentely disabled. Writes to the control
file are rejected.
'notsupported': SMT is not supported by the CPUThe command line option 'nosmt' sets the sysfs control to 'off'. This
can be changed to 'on' to reenable SMT during runtime.The command line option 'nosmt=force' sets the sysfs control to
'forceoff'. This cannot be changed during runtime.When SMT is 'on' and the control file is changed to 'off' then all online
secondary threads are offlined and attempts to online a secondary thread
later on are rejected.When SMT is 'off' and the control file is changed to 'on' then secondary
threads can be onlined again. The 'off' -> 'on' transition does not
automatically online the secondary threads.When the control file is set to 'forceoff', the behaviour is the same as
setting it to 'off', but the operation is irreversible and later writes to
the control file are rejected.When the control status is 'notsupported' then writes to the control file
are rejected.Signed-off-by: Thomas Gleixner
Reviewed-by: Konrad Rzeszutek Wilk
Acked-by: Ingo Molnar
16 Jun, 2018
1 commit
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As we move stuff around, some doc references are broken. Fix some of
them via this script:
./scripts/documentation-file-ref-check --fixManually checked if the produced result is valid, removing a few
false-positives.Acked-by: Takashi Iwai
Acked-by: Masami Hiramatsu
Acked-by: Stephen Boyd
Acked-by: Charles Keepax
Acked-by: Mathieu Poirier
Reviewed-by: Coly Li
Signed-off-by: Mauro Carvalho Chehab
Acked-by: Jonathan Corbet
15 Jun, 2018
1 commit
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HAVE_CC_STACKPROTECTOR should be selected by architectures with stack
canary implementation. It is not about the compiler support.For the consistency with commit 050e9baa9dc9 ("Kbuild: rename
CC_STACKPROTECTOR[_STRONG] config variables"), remove 'CC_' from the
config symbol.I moved the 'select' lines to keep the alphabetical sorting.
Signed-off-by: Masahiro Yamada
Acked-by: Kees Cook
Signed-off-by: Linus Torvalds
14 Jun, 2018
1 commit
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The changes to automatically test for working stack protector compiler
support in the Kconfig files removed the special STACKPROTECTOR_AUTO
option that picked the strongest stack protector that the compiler
supported.That was all a nice cleanup - it makes no sense to have the AUTO case
now that the Kconfig phase can just determine the compiler support
directly.HOWEVER.
It also meant that doing "make oldconfig" would now _disable_ the strong
stackprotector if you had AUTO enabled, because in a legacy config file,
the sane stack protector configuration would look likeCONFIG_HAVE_CC_STACKPROTECTOR=y
# CONFIG_CC_STACKPROTECTOR_NONE is not set
# CONFIG_CC_STACKPROTECTOR_REGULAR is not set
# CONFIG_CC_STACKPROTECTOR_STRONG is not set
CONFIG_CC_STACKPROTECTOR_AUTO=yand when you ran this through "make oldconfig" with the Kbuild changes,
it would ask you about the regular CONFIG_CC_STACKPROTECTOR (that had
been renamed from CONFIG_CC_STACKPROTECTOR_REGULAR to just
CONFIG_CC_STACKPROTECTOR), but it would think that the STRONG version
used to be disabled (because it was really enabled by AUTO), and would
disable it in the new config, resulting in:CONFIG_HAVE_CC_STACKPROTECTOR=y
CONFIG_CC_HAS_STACKPROTECTOR_NONE=y
CONFIG_CC_STACKPROTECTOR=y
# CONFIG_CC_STACKPROTECTOR_STRONG is not set
CONFIG_CC_HAS_SANE_STACKPROTECTOR=yThat's dangerously subtle - people could suddenly find themselves with
the weaker stack protector setup without even realizing.The solution here is to just rename not just the old RECULAR stack
protector option, but also the strong one. This does that by just
removing the CC_ prefix entirely for the user choices, because it really
is not about the compiler support (the compiler support now instead
automatially impacts _visibility_ of the options to users).This results in "make oldconfig" actually asking the user for their
choice, so that we don't have any silent subtle security model changes.
The end result would generally look like this:CONFIG_HAVE_CC_STACKPROTECTOR=y
CONFIG_CC_HAS_STACKPROTECTOR_NONE=y
CONFIG_STACKPROTECTOR=y
CONFIG_STACKPROTECTOR_STRONG=y
CONFIG_CC_HAS_SANE_STACKPROTECTOR=ywhere the "CC_" versions really are about internal compiler
infrastructure, not the user selections.Acked-by: Masahiro Yamada
Signed-off-by: Linus Torvalds
13 Jun, 2018
1 commit
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Pull more Kbuild updates from Masahiro Yamada:
- fix some bugs introduced by the recent Kconfig syntax extension
- add some symbols about compiler information in Kconfig, such as
CC_IS_GCC, CC_IS_CLANG, GCC_VERSION, etc.- test compiler capability for the stack protector in Kconfig, and
clean-up Makefile- test compiler capability for GCC-plugins in Kconfig, and clean-up
Makefile- allow to enable GCC-plugins for COMPILE_TEST
- test compiler capability for KCOV in Kconfig and correct dependency
- remove auto-detect mode of the GCOV format, which is now more nicely
handled in Kconfig- test compiler capability for mprofile-kernel on PowerPC, and clean-up
Makefile- misc cleanups
* tag 'kbuild-v4.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
linux/linkage.h: replace VMLINUX_SYMBOL_STR() with __stringify()
kconfig: fix localmodconfig
sh: remove no-op macro VMLINUX_SYMBOL()
powerpc/kbuild: move -mprofile-kernel check to Kconfig
Documentation: kconfig: add recommended way to describe compiler support
gcc-plugins: disable GCC_PLUGIN_STRUCTLEAK_BYREF_ALL for COMPILE_TEST
gcc-plugins: allow to enable GCC_PLUGINS for COMPILE_TEST
gcc-plugins: test plugin support in Kconfig and clean up Makefile
gcc-plugins: move GCC version check for PowerPC to Kconfig
kcov: test compiler capability in Kconfig and correct dependency
gcov: remove CONFIG_GCOV_FORMAT_AUTODETECT
arm64: move GCC version check for ARCH_SUPPORTS_INT128 to Kconfig
kconfig: add CC_IS_CLANG and CLANG_VERSION
kconfig: add CC_IS_GCC and GCC_VERSION
stack-protector: test compiler capability in Kconfig and drop AUTO mode
kbuild: fix endless syncconfig in case arch Makefile sets CROSS_COMPILE
11 Jun, 2018
4 commits
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We have enabled GCC_PLUGINS for COMPILE_TEST, but allmodconfig now
produces new warnings.CC [M] drivers/net/wireless/broadcom/brcm80211/brcmsmac/phy/phy_n.o
drivers/net/wireless/broadcom/brcm80211/brcmsmac/phy/phy_n.c: In function ‘wlc_phy_workarounds_nphy_rev7’:
drivers/net/wireless/broadcom/brcm80211/brcmsmac/phy/phy_n.c:16563:1: warning: the frame size of 3128 bytes is larger than 2048 bytes [-Wframe-larger-than=]
}
^
drivers/net/wireless/broadcom/brcm80211/brcmsmac/phy/phy_n.c: In function ‘wlc_phy_workarounds_nphy_rev3’:
drivers/net/wireless/broadcom/brcm80211/brcmsmac/phy/phy_n.c:16905:1: warning: the frame size of 2800 bytes is larger than 2048 bytes [-Wframe-larger-than=]
}
^
drivers/net/wireless/broadcom/brcm80211/brcmsmac/phy/phy_n.c: In function ‘wlc_phy_cal_txiqlo_nphy’:
drivers/net/wireless/broadcom/brcm80211/brcmsmac/phy/phy_n.c:26033:1: warning: the frame size of 2488 bytes is larger than 2048 bytes [-Wframe-larger-than=]
}
^It looks like GCC_PLUGIN_STRUCTLEAK_BYREF_ALL is causing this.
Add "depends on !COMPILE_TEST" to not dirturb the compile test.Reported-by: Stephen Rothwell
Suggested-by: Kees Cook
Signed-off-by: Masahiro Yamada -
Now that the compiler's plugin support is checked in Kconfig,
all{yes,mod}config will not be bothered.Remove 'depends on !COMPILE_TEST' for GCC_PLUGINS.
'depends on !COMPILE_TEST' for the following three are still kept:
GCC_PLUGIN_CYC_COMPLEXITY
GCC_PLUGIN_STRUCTLEAK_VERBOSE
GCC_PLUGIN_RANDSTRUCT_PERFORMANCEKees suggested to do so because the first two are too noisy, and the
last one would reduce the compile test coverage. I commented the
reasons in arch/Kconfig.Signed-off-by: Masahiro Yamada
Acked-by: Kees Cook -
Run scripts/gcc-plugin.sh from Kconfig so that users can enable
GCC_PLUGINS only when the compiler supports building plugins.Kconfig defines a new symbol, PLUGIN_HOSTCC. This will contain
the compiler (g++ or gcc) used for building plugins, or empty
if the plugin can not be supported at all.This allows us to remove all ugly testing in Makefile.gcc-plugins.
Signed-off-by: Masahiro Yamada
Acked-by: Kees Cook -
Pull restartable sequence support from Thomas Gleixner:
"The restartable sequences syscall (finally):After a lot of back and forth discussion and massive delays caused by
the speculative distraction of maintainers, the core set of
restartable sequences has finally reached a consensus.It comes with the basic non disputed core implementation along with
support for arm, powerpc and x86 and a full set of selftestsIt was exposed to linux-next earlier this week, so it does not fully
comply with the merge window requirements, but there is really no
point to drag it out for yet another cycle"* 'core-rseq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
rseq/selftests: Provide Makefile, scripts, gitignore
rseq/selftests: Provide parametrized tests
rseq/selftests: Provide basic percpu ops test
rseq/selftests: Provide basic test
rseq/selftests: Provide rseq library
selftests/lib.mk: Introduce OVERRIDE_TARGETS
powerpc: Wire up restartable sequences system call
powerpc: Add syscall detection for restartable sequences
powerpc: Add support for restartable sequences
x86: Wire up restartable sequence system call
x86: Add support for restartable sequences
arm: Wire up restartable sequences system call
arm: Add syscall detection for restartable sequences
arm: Add restartable sequences support
rseq: Introduce restartable sequences system call
uapi/headers: Provide types_32_64.h
08 Jun, 2018
1 commit
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Move the test for -fstack-protector(-strong) option to Kconfig.
If the compiler does not support the option, the corresponding menu
is automatically hidden. If STRONG is not supported, it will fall
back to REGULAR. If REGULAR is not supported, it will be disabled.
This means, AUTO is implicitly handled by the dependency solver of
Kconfig, hence removed.I also turned the 'choice' into only two boolean symbols. The use of
'choice' is not a good idea here, because all of all{yes,mod,no}config
would choose the first visible value, while we want allnoconfig to
disable as many features as possible.X86 has additional shell scripts in case the compiler supports those
options, but generates broken code. I added CC_HAS_SANE_STACKPROTECTOR
to test this. I had to add -m32 to gcc-x86_32-has-stack-protector.sh
to make it work correctly.Signed-off-by: Masahiro Yamada
Acked-by: Kees Cook
07 Jun, 2018
1 commit
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Pull Kbuild updates from Masahiro Yamada:
- improve fixdep to coalesce consecutive slashes in dep-files
- fix some issues of the maintainer string generation in deb-pkg script
- remove unused CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX and clean-up
several tools and linker scripts- clean-up modpost
- allow to enable the dead code/data elimination for PowerPC in EXPERT
mode- improve two coccinelle scripts for better performance
- pass endianness and machine size flags to sparse for all architecture
- misc fixes
* tag 'kbuild-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (25 commits)
kbuild: add machine size to CHECKFLAGS
kbuild: add endianness flag to CHEKCFLAGS
kbuild: $(CHECK) doesnt need NOSTDINC_FLAGS twice
scripts: Fixed printf format mismatch
scripts/tags.sh: use `find` for $ALLSOURCE_ARCHS generation
coccinelle: deref_null: improve performance
coccinelle: mini_lock: improve performance
powerpc: Allow LD_DEAD_CODE_DATA_ELIMINATION to be selected
kbuild: Allow LD_DEAD_CODE_DATA_ELIMINATION to be selectable if enabled
kbuild: LD_DEAD_CODE_DATA_ELIMINATION no -ffunction-sections/-fdata-sections for module build
kbuild: Fix asm-generic/vmlinux.lds.h for LD_DEAD_CODE_DATA_ELIMINATION
modpost: constify *modname function argument where possible
modpost: remove redundant is_vmlinux() test
modpost: use strstarts() helper more widely
modpost: pass struct elf_info pointer to get_modinfo()
checkpatch: remove VMLINUX_SYMBOL() check
vmlinux.lds.h: remove no-op macro VMLINUX_SYMBOL()
kbuild: remove CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
export.h: remove code for prefixing symbols with underscore
depmod.sh: remove symbol prefix support
...
06 Jun, 2018
1 commit
-
Expose a new system call allowing each thread to register one userspace
memory area to be used as an ABI between kernel and user-space for two
purposes: user-space restartable sequences and quick access to read the
current CPU number value from user-space.* Restartable sequences (per-cpu atomics)
Restartables sequences allow user-space to perform update operations on
per-cpu data without requiring heavy-weight atomic operations.The restartable critical sections (percpu atomics) work has been started
by Paul Turner and Andrew Hunter. It lets the kernel handle restart of
critical sections. [1] [2] The re-implementation proposed here brings a
few simplifications to the ABI which facilitates porting to other
architectures and speeds up the user-space fast path.Here are benchmarks of various rseq use-cases.
Test hardware:
arm32: ARMv7 Processor rev 4 (v7l) "Cubietruck", 2-core
x86-64: Intel E5-2630 v3@2.40GHz, 16-core, hyperthreadingThe following benchmarks were all performed on a single thread.
* Per-CPU statistic counter increment
getcpu+atomic (ns/op) rseq (ns/op) speedup
arm32: 344.0 31.4 11.0
x86-64: 15.3 2.0 7.7* LTTng-UST: write event 32-bit header, 32-bit payload into tracer
per-cpu buffergetcpu+atomic (ns/op) rseq (ns/op) speedup
arm32: 2502.0 2250.0 1.1
x86-64: 117.4 98.0 1.2* liburcu percpu: lock-unlock pair, dereference, read/compare word
getcpu+atomic (ns/op) rseq (ns/op) speedup
arm32: 751.0 128.5 5.8
x86-64: 53.4 28.6 1.9* jemalloc memory allocator adapted to use rseq
Using rseq with per-cpu memory pools in jemalloc at Facebook (based on
rseq 2016 implementation):The production workload response-time has 1-2% gain avg. latency, and
the P99 overall latency drops by 2-3%.* Reading the current CPU number
Speeding up reading the current CPU number on which the caller thread is
running is done by keeping the current CPU number up do date within the
cpu_id field of the memory area registered by the thread. This is done
by making scheduler preemption set the TIF_NOTIFY_RESUME flag on the
current thread. Upon return to user-space, a notify-resume handler
updates the current CPU value within the registered user-space memory
area. User-space can then read the current CPU number directly from
memory.Keeping the current cpu id in a memory area shared between kernel and
user-space is an improvement over current mechanisms available to read
the current CPU number, which has the following benefits over
alternative approaches:- 35x speedup on ARM vs system call through glibc
- 20x speedup on x86 compared to calling glibc, which calls vdso
executing a "lsl" instruction,
- 14x speedup on x86 compared to inlined "lsl" instruction,
- Unlike vdso approaches, this cpu_id value can be read from an inline
assembly, which makes it a useful building block for restartable
sequences.
- The approach of reading the cpu id through memory mapping shared
between kernel and user-space is portable (e.g. ARM), which is not the
case for the lsl-based x86 vdso.On x86, yet another possible approach would be to use the gs segment
selector to point to user-space per-cpu data. This approach performs
similarly to the cpu id cache, but it has two disadvantages: it is
not portable, and it is incompatible with existing applications already
using the gs segment selector for other purposes.Benchmarking various approaches for reading the current CPU number:
ARMv7 Processor rev 4 (v7l)
Machine model: Cubietruck
- Baseline (empty loop): 8.4 ns
- Read CPU from rseq cpu_id: 16.7 ns
- Read CPU from rseq cpu_id (lazy register): 19.8 ns
- glibc 2.19-0ubuntu6.6 getcpu: 301.8 ns
- getcpu system call: 234.9 nsx86-64 Intel(R) Xeon(R) CPU E5-2630 v3 @ 2.40GHz:
- Baseline (empty loop): 0.8 ns
- Read CPU from rseq cpu_id: 0.8 ns
- Read CPU from rseq cpu_id (lazy register): 0.8 ns
- Read using gs segment selector: 0.8 ns
- "lsl" inline assembly: 13.0 ns
- glibc 2.19-0ubuntu6 getcpu: 16.6 ns
- getcpu system call: 53.9 ns- Speed (benchmark taken on v8 of patchset)
Running 10 runs of hackbench -l 100000 seems to indicate, contrary to
expectations, that enabling CONFIG_RSEQ slightly accelerates the
scheduler:Configuration: 2 sockets * 8-core Intel(R) Xeon(R) CPU E5-2630 v3 @
2.40GHz (directly on hardware, hyperthreading disabled in BIOS, energy
saving disabled in BIOS, turboboost disabled in BIOS, cpuidle.off=1
kernel parameter), with a Linux v4.6 defconfig+localyesconfig,
restartable sequences series applied.* CONFIG_RSEQ=n
avg.: 41.37 s
std.dev.: 0.36 s* CONFIG_RSEQ=y
avg.: 40.46 s
std.dev.: 0.33 s- Size
On x86-64, between CONFIG_RSEQ=n/y, the text size increase of vmlinux is
567 bytes, and the data size increase of vmlinux is 5696 bytes.[1] https://lwn.net/Articles/650333/
[2] http://www.linuxplumbersconf.org/2013/ocw/system/presentations/1695/original/LPC%20-%20PerCpu%20Atomics.pdfSigned-off-by: Mathieu Desnoyers
Signed-off-by: Thomas Gleixner
Acked-by: Peter Zijlstra (Intel)
Cc: Joel Fernandes
Cc: Catalin Marinas
Cc: Dave Watson
Cc: Will Deacon
Cc: Andi Kleen
Cc: "H . Peter Anvin"
Cc: Chris Lameter
Cc: Russell King
Cc: Andrew Hunter
Cc: Michael Kerrisk
Cc: "Paul E . McKenney"
Cc: Paul Turner
Cc: Boqun Feng
Cc: Josh Triplett
Cc: Steven Rostedt
Cc: Ben Maurer
Cc: Alexander Viro
Cc: linux-api@vger.kernel.org
Cc: Andy Lutomirski
Cc: Andrew Morton
Cc: Linus Torvalds
Link: http://lkml.kernel.org/r/20151027235635.16059.11630.stgit@pjt-glaptop.roam.corp.google.com
Link: http://lkml.kernel.org/r/20150624222609.6116.86035.stgit@kitami.mtv.corp.google.com
Link: https://lkml.kernel.org/r/20180602124408.8430-3-mathieu.desnoyers@efficios.com
05 Jun, 2018
2 commits
-
Pull timers and timekeeping updates from Thomas Gleixner:
- Core infrastucture work for Y2038 to address the COMPAT interfaces:
+ Add a new Y2038 safe __kernel_timespec and use it in the core
code+ Introduce config switches which allow to control the various
compat mechanisms+ Use the new config switch in the posix timer code to control the
32bit compat syscall implementation.- Prevent bogus selection of CPU local clocksources which causes an
endless reselection loop- Remove the extra kthread in the clocksource code which has no value
and just adds another level of indirection- The usual bunch of trivial updates, cleanups and fixlets all over the
place- More SPDX conversions
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
clocksource/drivers/mxs_timer: Switch to SPDX identifier
clocksource/drivers/timer-imx-tpm: Switch to SPDX identifier
clocksource/drivers/timer-imx-gpt: Switch to SPDX identifier
clocksource/drivers/timer-imx-gpt: Remove outdated file path
clocksource/drivers/arc_timer: Add comments about locking while read GFRC
clocksource/drivers/mips-gic-timer: Add pr_fmt and reword pr_* messages
clocksource/drivers/sprd: Fix Kconfig dependency
clocksource: Move inline keyword to the beginning of function declarations
timer_list: Remove unused function pointer typedef
timers: Adjust a kernel-doc comment
tick: Prefer a lower rating device only if it's CPU local device
clocksource: Remove kthread
time: Change nanosleep to safe __kernel_* types
time: Change types to new y2038 safe __kernel_* types
time: Fix get_timespec64() for y2038 safe compat interfaces
time: Add new y2038 safe __kernel_timespec
posix-timers: Make compat syscalls depend on CONFIG_COMPAT_32BIT_TIME
time: Introduce CONFIG_COMPAT_32BIT_TIME
time: Introduce CONFIG_64BIT_TIME in architectures
compat: Enable compat_get/put_timespec64 always
... -
Pull dma-mapping updates from Christoph Hellwig:
- replace the force_dma flag with a dma_configure bus method. (Nipun
Gupta, although one patch is іncorrectly attributed to me due to a
git rebase bug)- use GFP_DMA32 more agressively in dma-direct. (Takashi Iwai)
- remove PCI_DMA_BUS_IS_PHYS and rely on the dma-mapping API to do the
right thing for bounce buffering.- move dma-debug initialization to common code, and apply a few
cleanups to the dma-debug code.- cleanup the Kconfig mess around swiotlb selection
- swiotlb comment fixup (Yisheng Xie)
- a trivial swiotlb fix. (Dan Carpenter)
- support swiotlb on RISC-V. (based on a patch from Palmer Dabbelt)
- add a new generic dma-noncoherent dma_map_ops implementation and use
it for arc, c6x and nds32.- improve scatterlist validity checking in dma-debug. (Robin Murphy)
- add a struct device quirk to limit the dma-mask to 32-bit due to
bridge/system issues, and switch x86 to use it instead of a local
hack for VIA bridges.- handle devices without a dma_mask more gracefully in the dma-direct
code.* tag 'dma-mapping-4.18' of git://git.infradead.org/users/hch/dma-mapping: (48 commits)
dma-direct: don't crash on device without dma_mask
nds32: use generic dma_noncoherent_ops
nds32: implement the unmap_sg DMA operation
nds32: consolidate DMA cache maintainance routines
x86/pci-dma: switch the VIA 32-bit DMA quirk to use the struct device flag
x86/pci-dma: remove the explicit nodac and allowdac option
x86/pci-dma: remove the experimental forcesac boot option
Documentation/x86: remove a stray reference to pci-nommu.c
core, dma-direct: add a flag 32-bit dma limits
dma-mapping: remove unused gfp_t parameter to arch_dma_alloc_attrs
dma-debug: check scatterlist segments
c6x: use generic dma_noncoherent_ops
arc: use generic dma_noncoherent_ops
arc: fix arc_dma_{map,unmap}_page
arc: fix arc_dma_sync_sg_for_{cpu,device}
arc: simplify arc_dma_sync_single_for_{cpu,device}
dma-mapping: provide a generic dma-noncoherent implementation
dma-mapping: simplify Kconfig dependencies
riscv: add swiotlb support
riscv: only enable ZONE_DMA32 for 64-bit
...
17 May, 2018
2 commits
-
Architectures that are capable can select
HAVE_LD_DEAD_CODE_DATA_ELIMINATION to enable selection of that
option (as an EXPERT kernel option).Signed-off-by: Nicholas Piggin
Signed-off-by: Masahiro Yamada -
CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX was selected by BLACKFIN, METAG.
They were removed by commit 4ba66a976072 ("arch: remove blackfin port"),
commit bb6fb6dfcc17 ("metag: Remove arch/metag/"), respectively.No more architecture enables CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX.
Clean up the rest of scripts, and remove the Kconfig entry.Signed-off-by: Masahiro Yamada
Reviewed-by: Sam Ravnborg
12 May, 2018
1 commit
-
Currently STRUCTLEAK inserts initialization out of live scope of variables
from KASAN point of view. This leads to KASAN false positive reports.
Prohibit this combination for now.Link: http://lkml.kernel.org/r/20180419172451.104700-1-dvyukov@google.com
Signed-off-by: Dmitry Vyukov
Acked-by: Kees Cook
Cc: Fengguang Wu
Cc: Sergey Senozhatsky
Cc: Andrey Ryabinin
Cc: Dennis Zhou
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
08 May, 2018
1 commit
-
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
Reviewed-by: Robin Murphy
19 Apr, 2018
2 commits
-
Compat functions are now used to support 32 bit time_t in
compat mode on 64 bit architectures and in native mode on
32 bit architectures.Introduce COMPAT_32BIT_TIME to conditionally compile these
functions.Note that turning off 32 bit time_t support requires more
changes on architecture side. For instance, architecure
syscall tables need to be updated to drop support for 32 bit
time_t syscalls.Signed-off-by: Deepa Dinamani
Signed-off-by: Arnd Bergmann -
There are a total of 53 system calls (aside from ioctl) that pass a time_t
or derived data structure as an argument, and in order to extend time_t
to 64-bit, we have to replace them with new system calls and keep providing
backwards compatibility.To avoid adding completely new and untested code for this purpose, we
introduce a new CONFIG_64BIT_TIME symbol. Every architecture that supports
new 64 bit time_t syscalls enables this config.After this is done for all architectures, the CONFIG_64BIT_TIME symbol
will be deleted.Signed-off-by: Arnd Bergmann
Signed-off-by: Deepa Dinamani
Signed-off-by: Arnd Bergmann
26 Mar, 2018
1 commit
-
This removes the old `ld -r` incremental link option, which has not
been selected by any architecture since June 2017.Signed-off-by: Nicholas Piggin
Signed-off-by: Masahiro Yamada
07 Feb, 2018
2 commits
-
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
Tested-by: Laura Abbott
Cc: Masahiro Yamada
Cc: Arnd Bergmann
Cc: Josh Triplett
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Tested-by: Laura Abbott
Cc: Masahiro Yamada
Cc: Arnd Bergmann
Cc: Josh Triplett
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
04 Feb, 2018
1 commit
-
Pull hardened usercopy whitelisting from Kees Cook:
"Currently, hardened usercopy performs dynamic bounds checking on slab
cache objects. This is good, but still leaves a lot of kernel memory
available to be copied to/from userspace in the face of bugs.To further restrict what memory is available for copying, this creates
a way to whitelist specific areas of a given slab cache object for
copying to/from userspace, allowing much finer granularity of access
control.Slab caches that are never exposed to userspace can declare no
whitelist for their objects, thereby keeping them unavailable to
userspace via dynamic copy operations. (Note, an implicit form of
whitelisting is the use of constant sizes in usercopy operations and
get_user()/put_user(); these bypass all hardened usercopy checks since
these sizes cannot change at runtime.)This new check is WARN-by-default, so any mistakes can be found over
the next several releases without breaking anyone's system.The series has roughly the following sections:
- remove %p and improve reporting with offset
- prepare infrastructure and whitelist kmalloc
- update VFS subsystem with whitelists
- update SCSI subsystem with whitelists
- update network subsystem with whitelists
- update process memory with whitelists
- update per-architecture thread_struct with whitelists
- update KVM with whitelists and fix ioctl bug
- mark all other allocations as not whitelisted
- update lkdtm for more sensible test overage"* tag 'usercopy-v4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (38 commits)
lkdtm: Update usercopy tests for whitelisting
usercopy: Restrict non-usercopy caches to size 0
kvm: x86: fix KVM_XEN_HVM_CONFIG ioctl
kvm: whitelist struct kvm_vcpu_arch
arm: Implement thread_struct whitelist for hardened usercopy
arm64: Implement thread_struct whitelist for hardened usercopy
x86: Implement thread_struct whitelist for hardened usercopy
fork: Provide usercopy whitelisting for task_struct
fork: Define usercopy region in thread_stack slab caches
fork: Define usercopy region in mm_struct slab caches
net: Restrict unwhitelisted proto caches to size 0
sctp: Copy struct sctp_sock.autoclose to userspace using put_user()
sctp: Define usercopy region in SCTP proto slab cache
caif: Define usercopy region in caif proto slab cache
ip: Define usercopy region in IP proto slab cache
net: Define usercopy region in struct proto slab cache
scsi: Define usercopy region in scsi_sense_cache slab cache
cifs: Define usercopy region in cifs_request slab cache
vxfs: Define usercopy region in vxfs_inode slab cache
ufs: Define usercopy region in ufs_inode_cache slab cache
...
01 Feb, 2018
2 commits
-
Pull networking updates from David Miller:
1) Significantly shrink the core networking routing structures. Result
of http://vger.kernel.org/~davem/seoul2017_netdev_keynote.pdf2) 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
... -
Pull dma mapping updates from Christoph Hellwig:
"Except for a runtime warning fix from Christian this is all about
consolidation of the generic no-IOMMU code, a well as the glue code
for swiotlb.All the code is based on the x86 implementation with hooks to allow
all architectures that aren't cache coherent to use it.The x86 conversion itself has been deferred because the x86
maintainers were a little busy in the last months"* tag 'dma-mapping-4.16' of git://git.infradead.org/users/hch/dma-mapping: (57 commits)
MAINTAINERS: add the iommu list for swiotlb and xen-swiotlb
arm64: use swiotlb_alloc and swiotlb_free
arm64: replace ZONE_DMA with ZONE_DMA32
mips: use swiotlb_{alloc,free}
mips/netlogic: remove swiotlb support
tile: use generic swiotlb_ops
tile: replace ZONE_DMA with ZONE_DMA32
unicore32: use generic swiotlb_ops
ia64: remove an ifdef around the content of pci-dma.c
ia64: clean up swiotlb support
ia64: use generic swiotlb_ops
ia64: replace ZONE_DMA with ZONE_DMA32
swiotlb: remove various exports
swiotlb: refactor coherent buffer allocation
swiotlb: refactor coherent buffer freeing
swiotlb: wire up ->dma_supported in swiotlb_dma_ops
swiotlb: add common swiotlb_map_ops
swiotlb: rename swiotlb_free to swiotlb_exit
x86: rename swiotlb_dma_ops
powerpc: rename swiotlb_dma_ops
...
16 Jan, 2018
1 commit
-
While the blocked and saved_sigmask fields of task_struct are copied to
userspace (via sigmask_to_save() and setup_rt_frame()), it is always
copied with a static length (i.e. sizeof(sigset_t)).The only portion of task_struct that is potentially dynamically sized and
may be copied to userspace is in the architecture-specific thread_struct
at the end of task_struct.cache object allocation:
kernel/fork.c:
alloc_task_struct_node(...):
return kmem_cache_alloc_node(task_struct_cachep, ...);dup_task_struct(...):
...
tsk = alloc_task_struct_node(node);copy_process(...):
...
dup_task_struct(...)_do_fork(...):
...
copy_process(...)example usage trace:
arch/x86/kernel/fpu/signal.c:
__fpu__restore_sig(...):
...
struct task_struct *tsk = current;
struct fpu *fpu = &tsk->thread.fpu;
...
__copy_from_user(&fpu->state.xsave, ..., state_size);fpu__restore_sig(...):
...
return __fpu__restore_sig(...);arch/x86/kernel/signal.c:
restore_sigcontext(...):
...
fpu__restore_sig(...)This introduces arch_thread_struct_whitelist() to let an architecture
declare specifically where the whitelist should be within thread_struct.
If undefined, the entire thread_struct field is left whitelisted.Cc: Andrew Morton
Cc: Nicholas Piggin
Cc: Laura Abbott
Cc: "Mickaël Salaün"
Cc: Ingo Molnar
Cc: Thomas Gleixner
Cc: Andy Lutomirski
Signed-off-by: Kees Cook
Acked-by: Rik van Riel
13 Jan, 2018
1 commit
-
Since error-injection framework is not limited to be used
by kprobes, nor bpf. Other kernel subsystems can use it
freely for checking safeness of error-injection, e.g.
livepatch, ftrace etc.
So this separate error-injection framework from kprobes.Some differences has been made:
- "kprobe" word is removed from any APIs/structures.
- BPF_ALLOW_ERROR_INJECTION() is renamed to
ALLOW_ERROR_INJECTION() since it is not limited for BPF too.
- CONFIG_FUNCTION_ERROR_INJECTION is the config item of this
feature. It is automatically enabled if the arch supports
error injection feature for kprobe or ftrace etc.Signed-off-by: Masami Hiramatsu
Reviewed-by: Josef Bacik
Signed-off-by: Alexei Starovoitov
10 Jan, 2018
1 commit
-
phys_to_dma, dma_to_phys and dma_capable are helpers published by
architecture code for use of swiotlb and xen-swiotlb only. Drivers are
not supposed to use these directly, but use the DMA API instead.Move these to a new asm/dma-direct.h helper, included by a
linux/dma-direct.h wrapper that provides the default linear mapping
unless the architecture wants to override it.In the MIPS case the existing dma-coherent.h is reused for now as
untangling it will take a bit of work.Signed-off-by: Christoph Hellwig
Acked-by: Robin Murphy