tjh.dev
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.
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Pull DeviceTree fixes from Rob Herring:
- fix build for !OF providing empty of_find_device_by_node
- fix Abracon vendor prefix
- sync dtx_diff include paths (again)
- a stm32h7 clock binding doc fix
* tag 'devicetree-fixes-for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
dt-bindings: clk: stm32h7: fix clock-cell size
scripts/dtc: dtx_diff - 2nd update of include dts paths to match build
dt-bindings: fix vendor prefix for Abracon
of: provide inline helper for of_find_device_by_node
Pull x86 fixes from Ingo Molnar:
"Another round of CR3/PCID related fixes (I think this addresses all
but one of the known problems with PCID support), an objtool fix plus
a Clang fix that (finally) solves all Clang quirks to build a bootable
x86 kernel as-is"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/asm: Fix inline asm call constraints for Clang
objtool: Handle another GCC stack pointer adjustment bug
x86/mm/32: Load a sane CR3 before cpu_init() on secondary CPUs
x86/mm/32: Move setup_clear_cpu_cap(X86_FEATURE_PCID) earlier
x86/mm/64: Stop using CR3.PCID == 0 in ASID-aware code
x86/mm: Factor out CR3-building code
The clock-cell size is 1 on stm32h7 plaform.
Signed-off-by: Gabriel Fernandez <gabriel.fernandez@st.com>
Fixes: 3e4d618b0722 ("clk: stm32h7: Add stm32h743 clock driver")
Signed-off-by: Rob Herring <robh@kernel.org>
Pull timer fix from Ingo Molnar:
"A clocksource driver section mismatch fix"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
clocksource/integrator: Fix section mismatch warning
For inline asm statements which have a CALL instruction, we list the
stack pointer as a constraint to convince GCC to ensure the frame
pointer is set up first:
static inline void foo()
{
register void *__sp asm(_ASM_SP);
asm("call bar" : "+r" (__sp))
}
Unfortunately, that pattern causes Clang to corrupt the stack pointer.
The fix is easy: convert the stack pointer register variable to a global
variable.
It should be noted that the end result is different based on the GCC
version. With GCC 6.4, this patch has exactly the same result as
before:
defconfig defconfig-nofp distro distro-nofp
before 9820389 9491555 8816046 8516940
after 9820389 9491555 8816046 8516940
With GCC 7.2, however, GCC's behavior has changed. It now changes its
behavior based on the conversion of the register variable to a global.
That somehow convinces it to *always* set up the frame pointer before
inserting *any* inline asm. (Therefore, listing the variable as an
output constraint is a no-op and is no longer necessary.) It's a bit
overkill, but the performance impact should be negligible. And in fact,
there's a nice improvement with frame pointers disabled:
defconfig defconfig-nofp distro distro-nofp
before 9796316 9468236 9076191 8790305
after 9796957 9464267 9076381 8785949
So in summary, while listing the stack pointer as an output constraint
is no longer necessary for newer versions of GCC, it's still needed for
older versions.
Suggested-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reported-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Miguel Bernal Marin <miguel.bernal.marin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/3db862e970c432ae823cf515c52b54fec8270e0e.1505942196.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Update dtx_diff include paths in the same manner as:
commit b12869a8d519 ("of: remove drivers/of/testcase-data from
include search path for CPP"), commit 5ffa2aed389c ("of: remove
arch/$(SRCARCH)/boot/dts from include search path for CPP"), and
commit 50f9ddaf64e1 ("of: search scripts/dtc/include-prefixes path
for both CPP and DTC").
Remove proposed include path kernel/dts/, which was never implemented
for the dtb build.
For the diff case, each source file is compiled separately. For
each of those compiles, provide the location of the source file
as an include path, not the location of both source files.
Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Pull irq fixes from Ingo Molnar:
"Three irqchip driver fixes, and an affinity mask helper function bug
fix affecting x86"
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
Revert "genirq: Restrict effective affinity to interrupts actually using it"
irqchip.mips-gic: Fix shared interrupt mask writes
irqchip/gic-v4: Fix building with ancient gcc
irqchip/gic-v3: Iterate over possible CPUs by for_each_possible_cpu()
gcc-4.6 and older fail to inline integrator_clocksource_init, so they
end up showing a harmless warning:
WARNING: vmlinux.o(.text+0x4aa94c): Section mismatch in reference from the function integrator_clocksource_init() to the function .init.text:clocksource_mmio_init()
The function integrator_clocksource_init() references
the function __init clocksource_mmio_init().
This is often because integrator_clocksource_init lacks a __init
annotation or the annotation of clocksource_mmio_init is wrong.
Add the missing __init annotation that makes it build cleanly with all
compilers.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: http://lkml.kernel.org/r/20170915194310.1170514-1-arnd@arndb.de
The kbuild bot reported the following warning with GCC 4.4 and a
randconfig:
net/socket.o: warning: objtool: compat_sock_ioctl()+0x1083: stack state mismatch: cfa1=7+160 cfa2=-1+0
This is caused by another GCC non-optimization, where it backs up and
restores the stack pointer for no apparent reason:
2f91: 48 89 e0 mov %rsp,%rax
2f94: 4c 89 e7 mov %r12,%rdi
2f97: 4c 89 f6 mov %r14,%rsi
2f9a: ba 20 00 00 00 mov $0x20,%edx
2f9f: 48 89 c4 mov %rax,%rsp
This issue would have been happily ignored before the following commit:
dd88a0a0c861 ("objtool: Handle GCC stack pointer adjustment bug")
But now that objtool is paying attention to such stack pointer writes
to/from a register, it needs to understand them properly. In this case
that means recognizing that the "mov %rsp, %rax" instruction is
potentially a backup of the stack pointer.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Miguel Bernal Marin <miguel.bernal.marin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: dd88a0a0c861 ("objtool: Handle GCC stack pointer adjustment bug")
Link: http://lkml.kernel.org/r/8c7aa8e9a36fbbb6655d9d8e7cea58958c912da8.1505942196.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit 446810f2dd41 ("of: add vendor prefix for Abracon Corporation")
claimed that "abcn" was used as the vendor prefix while in fact "abracon"
was used in the subsequent commits. It is also the only prefix used in the
tree.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
[robh: fix alphabetical order]
Signed-off-by: Rob Herring <robh@kernel.org>
Pull address-limit checking fixes from Ingo Molnar:
"This fixes a number of bugs in the address-limit (USER_DS) checks that
got introduced in the merge window, (mostly) affecting the ARM and
ARM64 platforms"
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
arm64/syscalls: Move address limit check in loop
arm/syscalls: Optimize address limit check
Revert "arm/syscalls: Check address limit on user-mode return"
syscalls: Use CHECK_DATA_CORRUPTION for addr_limit_user_check
Pull irqchip updates from Marc Zyngier
- A GICv3 initialisation fix when some CPUs fail to be brought up
- A GICv4 compile fix for GCC 4.5 (!)
- A MIPS-GIC fix for the PCIe support
Pull misc fixes from Thomas Gleixner:
- A fix for a user space regression in /proc/$PID/stat
- A couple of objtool fixes:
~ Plug a memory leak
~ Avoid accessing empty sections which upsets certain binutil
versions
~ Prevent corrupting the obj file when section sizes did not change
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
fs/proc: Report eip/esp in /prod/PID/stat for coredumping
objtool: Fix object file corruption
objtool: Do not retrieve data from empty sections
objtool: Fix memory leak in elf_create_rela_section()
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