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 ARM fixes from Russell King:
- LPAE fixes for kernel-readonly regions
- Fix for get_user_pages_fast on LPAE systems
- avoid tying decompressor to a particular platform if DEBUG_LL is
enabled
- BUG if we attempt to return to userspace but the to-be-restored PSR
value keeps us in privileged mode (defeating an issue that ftracetest
found)
* 'fixes' of git://git.armlinux.org.uk/~rmk/linux-arm:
ARM: BUG if jumping to usermode address in kernel mode
ARM: 8722/1: mm: make STRICT_KERNEL_RWX effective for LPAE
ARM: 8721/1: mm: dump: check hardware RO bit for LPAE
ARM: make decompressor debug output user selectable
ARM: fix get_user_pages_fast
Pull irq fixes from Thomas Glexiner:
- unbreak the irq trigger type check for legacy platforms
- a handful fixes for ARM GIC v3/4 interrupt controllers
- a few trivial fixes all over the place
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
genirq/matrix: Make - vs ?: Precedence explicit
irqchip/imgpdc: Use resource_size function on resource object
irqchip/qcom: Fix u32 comparison with value less than zero
irqchip/exiu: Fix return value check in exiu_init()
irqchip/gic-v3-its: Remove artificial dependency on PCI
irqchip/gic-v4: Add forward definition of struct irq_domain_ops
irqchip/gic-v3: pr_err() strings should end with newlines
irqchip/s3c24xx: pr_err() strings should end with newlines
irqchip/gic-v3: Fix ppi-partitions lookup
irqchip/gic-v4: Clear IRQ_DISABLE_UNLAZY again if mapping fails
genirq: Track whether the trigger type has been set
Detect if we are returning to usermode via the normal kernel exit paths
but the saved PSR value indicates that we are in kernel mode. This
could occur due to corrupted stack state, which has been observed with
"ftracetest".
This ensures that we catch the problem case before we get to user code.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Pull misc x86 fixes from Ingo Molnar:
- topology enumeration fixes
- KASAN fix
- two entry fixes (not yet the big series related to KASLR)
- remove obsolete code
- instruction decoder fix
- better /dev/mem sanity checks, hopefully working better this time
- pkeys fixes
- two ACPI fixes
- 5-level paging related fixes
- UMIP fixes that should make application visible faults more debuggable
- boot fix for weird virtualization environment
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
x86/decoder: Add new TEST instruction pattern
x86/PCI: Remove unused HyperTransport interrupt support
x86/umip: Fix insn_get_code_seg_params()'s return value
x86/boot/KASLR: Remove unused variable
x86/entry/64: Add missing irqflags tracing to native_load_gs_index()
x86/mm/kasan: Don't use vmemmap_populate() to initialize shadow
x86/entry/64: Fix entry_SYSCALL_64_after_hwframe() IRQ tracing
x86/pkeys/selftests: Fix protection keys write() warning
x86/pkeys/selftests: Rename 'si_pkey' to 'siginfo_pkey'
x86/mpx/selftests: Fix up weird arrays
x86/pkeys: Update documentation about availability
x86/umip: Print a warning into the syslog if UMIP-protected instructions are used
x86/smpboot: Fix __max_logical_packages estimate
x86/topology: Avoid wasting 128k for package id array
perf/x86/intel/uncore: Cache logical pkg id in uncore driver
x86/acpi: Reduce code duplication in mp_override_legacy_irq()
x86/acpi: Handle SCI interrupts above legacy space gracefully
x86/boot: Fix boot failure when SMP MP-table is based at 0
x86/mm: Limit mmap() of /dev/mem to valid physical addresses
x86/selftests: Add test for mapping placement for 5-level paging
...
Noticed with a Clang build. This improves the readability of the ?:
expression, as it has lower precedence than the - expression. Show
explicitly that - is evaluated first.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20171122205645.GA27125@beast
Currently, for ARM kernels with CONFIG_ARM_LPAE and
CONFIG_STRICT_KERNEL_RWX enabled, the 2MiB pages mapping the
kernel code and rodata are writable. They are marked read-only in
a software bit (L_PMD_SECT_RDONLY) but the hardware read-only bit
is not set (PMD_SECT_AP2).
For user mappings, the logic that propagates the software bit
to the hardware bit is in set_pmd_at(); but for the kernel,
section_update() writes the PMDs directly, skipping this logic.
The fix is to set PMD_SECT_AP2 for read-only sections in
section_update(), at the same time as L_PMD_SECT_RDONLY.
Fixes: 1e3479225acb ("ARM: 8275/1: mm: fix PMD_SECT_RDONLY undeclared compile error")
Signed-off-by: Philip Derrin <philip@cog.systems>
Reported-by: Neil Dick <neil@cog.systems>
Tested-by: Neil Dick <neil@cog.systems>
Tested-by: Laura Abbott <labbott@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Pull scheduler fixes from Ingo Molnar:
"Misc fixes: a documentation fix, a Sparse warning fix and a debugging
fix"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/debug: Fix task state recording/printout
sched/deadline: Don't use dubious signed bitfields
sched/deadline: Fix the description of runtime accounting in the documentation
The kbuild test robot reported this build warning:
Warning: arch/x86/tools/test_get_len found difference at <jump_table>:ffffffff8103dd2c
Warning: ffffffff8103dd82: f6 09 d8 testb $0xd8,(%rcx)
Warning: objdump says 3 bytes, but insn_get_length() says 2
Warning: decoded and checked 1569014 instructions with 1 warnings
This sequence seems to be a new instruction not in the opcode map in the Intel SDM.
The instruction sequence is "F6 09 d8", means Group3(F6), MOD(00)REG(001)RM(001), and 0xd8.
Intel SDM vol2 A.4 Table A-6 said the table index in the group is "Encoding of Bits 5,4,3 of
the ModR/M Byte (bits 2,1,0 in parenthesis)"
In that table, opcodes listed by the index REG bits as:
000 001 010 011 100 101 110 111
TEST Ib/Iz,(undefined),NOT,NEG,MUL AL/rAX,IMUL AL/rAX,DIV AL/rAX,IDIV AL/rAX
So, it seems TEST Ib is assigned to 001.
Add the new pattern.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <stable@vger.kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
drivers/irqchip/irq-imgpdc.c:327:20-23: WARNING: Suspicious code.
resource_size is maybe missing with res_regs
Generated by: scripts/coccinelle/api/resource_size.cocci
Signed-off-by: Vasyl Gomonovych <gomonovych@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: marc.zyngier@arm.com
Cc: jason@lakedaemon.net
Link: https://lkml.kernel.org/r/1511215361-8279-1-git-send-email-gomonovych@gmail.com
When CONFIG_ARM_LPAE is set, the PMD dump relies on the software
read-only bit to determine whether a page is writable. This
concealed a bug which left the kernel text section writable
(AP2=0) while marked read-only in the software bit.
In a kernel with the AP2 bug, the dump looks like this:
---[ Kernel Mapping ]---
0xc0000000-0xc0200000 2M RW NX SHD
0xc0200000-0xc0600000 4M ro x SHD
0xc0600000-0xc0800000 2M ro NX SHD
0xc0800000-0xc4800000 64M RW NX SHD
The fix is to check that the software and hardware bits are both
set before displaying "ro". The dump then shows the true perms:
---[ Kernel Mapping ]---
0xc0000000-0xc0200000 2M RW NX SHD
0xc0200000-0xc0600000 4M RW x SHD
0xc0600000-0xc0800000 2M RW NX SHD
0xc0800000-0xc4800000 64M RW NX SHD
Fixes: ded947798469 ("ARM: 8109/1: mm: Modify pte_write and pmd_write logic for LPAE")
Signed-off-by: Philip Derrin <philip@cog.systems>
Tested-by: Neil Dick <neil@cog.systems>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Pull perf fixes from Ingo Molnar:
"Misc fixes: two PMU driver fixes and a memory leak fix"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/core: Fix memory leak triggered by perf --namespace
perf/x86/intel/uncore: Add event constraint for BDX PCU
perf/x86/intel: Hide TSX events when RTM is not supported
The recent conversion of the task state recording to use task_state_index()
broke the sched_switch tracepoint task state output.
task_state_index() returns surprisingly an index (0-7) which is then
printed with __print_flags() applying bitmasks. Not really working and
resulting in weird states like 'prev_state=t' instead of 'prev_state=I'.
Use TASK_REPORT_MAX instead of TASK_STATE_MAX to report preemption. Build a
bitmask from the return value of task_state_index() and store it in
entry->prev_state, which makes __print_flags() work as expected.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: stable@vger.kernel.org
Fixes: efb40f588b43 ("sched/tracing: Fix trace_sched_switch task-state printing")
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1711221304180.1751@nanos
Signed-off-by: Ingo Molnar <mingo@kernel.org>
There are no in-tree callers of ht_create_irq(), the driver interface for
HyperTransport interrupts, left. Remove the unused entry point and all the
supporting code.
See 8b955b0dddb3 ("[PATCH] Initial generic hypertransport interrupt
support").
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-pci@vger.kernel.org
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Link: https://lkml.kernel.org/r/20171122221337.3877.23362.stgit@bhelgaas-glaptop.roam.corp.google.com
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