Rather than funneling through CC.
Also, use --hash-style=both just like other VDSO architectures and
glibc do.
Signed-off-by: David S. Miller <davem@davemloft.net>
Do not set any special register usage options, use the default which
is exactly what we should use for userspace code.
Make sure we remove the gcc plugin options from the 64-bit build.
The 32-bit cflags got it right already.
Signed-off-by: David S. Miller <davem@davemloft.net>
If the TICK_PRIV_BIT was set, we would not be able to read the tick
register in user space, which is where this code runs.
Signed-off-by: David S. Miller <davem@davemloft.net>
One interesting thing we need to do is stop using
__builtin_return_address() in get_vvar_data().
Simply read the %pc register instead.
Signed-off-by: David S. Miller <davem@davemloft.net>
The current VDSO patch mechanism has several problems:
1) It assumes how gcc will emit a function, with a register
window, an initial save instruction and then immediately
the %tick read when compiling vread_tick().
There is no such guarantees, code generation could change
at any time, gcc could put a nop between the save and
the %tick read, etc.
So this is extremely fragile and would fail some day.
2) It disallows us to properly inline vread_tick() into the callers
and thus get the best possible code sequences.
So fix this to patch properly, with location based annotations.
We have to be careful because we cannot do it the way we do
patches elsewhere in the kernel. Those use a sequence like:
1:
insn
.section .whatever_patch, "ax"
.word 1b
replacement_insn
.previous
This is a dynamic shared object, so that .word cannot be resolved at
build time, and thus cannot be used to execute the patches when the
kernel initializes the images.
Even trying to use label difference equations doesn't work in the
above kind of scheme:
1:
insn
.section .whatever_patch, "ax"
.word . - 1b
replacement_insn
.previous
The assembler complains that it cannot resolve that computation.
The issue is that this is contained in an executable section.
Borrow the sequence used by x86 alternatives, which is:
1:
insn
.pushsection .whatever_patch, "a"
.word . - 1b, . - 1f
.popsection
.pushsection .whatever_patch_replacements, "ax"
1:
replacement_insn
.previous
This works, allows us to inline vread_tick() as much as we like, and
can be used for arbitrary kinds of VDSO patching in the future.
Also, reverse the condition for patching. Most systems are %stick
based, so if we only patch on %tick systems the patching code will
get little or no testing.
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull dma mapping updates from Christoph Hellwig:
"First batch of dma-mapping changes for 4.20.
There will be a second PR as some big changes were only applied just
before the end of the merge window, and I want to give them a few more
days in linux-next.
Summary:
- mostly more consolidation of the direct mapping code, including
converting over hexagon, and merging the coherent and non-coherent
code into a single dma_map_ops instance (me)
- cleanups for the dma_configure/dma_unconfigure callchains (me)
- better handling of dma_masks in odd setups (me, Alexander Duyck)
- better debugging of passing vmalloc address to the DMA API (Stephen
Boyd)
- CMA command line parsing fix (He Zhe)"
* tag 'dma-mapping-4.20' of git://git.infradead.org/users/hch/dma-mapping: (27 commits)
dma-direct: respect DMA_ATTR_NO_WARN
dma-mapping: translate __GFP_NOFAIL to DMA_ATTR_NO_WARN
dma-direct: document the zone selection logic
dma-debug: Check for drivers mapping invalid addresses in dma_map_single()
dma-direct: fix return value of dma_direct_supported
dma-mapping: move dma_default_get_required_mask under ifdef
dma-direct: always allow dma mask <= physiscal memory size
dma-direct: implement complete bus_dma_mask handling
dma-direct: refine dma_direct_alloc zone selection
dma-direct: add an explicit dma_direct_get_required_mask
dma-mapping: make the get_required_mask method available unconditionally
unicore32: remove swiotlb support
Revert "dma-mapping: clear dev->dma_ops in arch_teardown_dma_ops"
dma-mapping: support non-coherent devices in dma_common_get_sgtable
dma-mapping: consolidate the dma mmap implementations
dma-mapping: merge direct and noncoherent ops
dma-mapping: move the dma_coherent flag to struct device
MIPS: don't select DMA_MAYBE_COHERENT from DMA_PERDEV_COHERENT
dma-mapping: add the missing ARCH_HAS_SYNC_DMA_FOR_CPU_ALL declaration
dma-mapping: fix panic caused by passing empty cma command line argument
...
Pull block layer updates from Jens Axboe:
"This is the main pull request for block changes for 4.20. This
contains:
- Series enabling runtime PM for blk-mq (Bart).
- Two pull requests from Christoph for NVMe, with items such as;
- Better AEN tracking
- Multipath improvements
- RDMA fixes
- Rework of FC for target removal
- Fixes for issues identified by static checkers
- Fabric cleanups, as prep for TCP transport
- Various cleanups and bug fixes
- Block merging cleanups (Christoph)
- Conversion of drivers to generic DMA mapping API (Christoph)
- Series fixing ref count issues with blkcg (Dennis)
- Series improving BFQ heuristics (Paolo, et al)
- Series improving heuristics for the Kyber IO scheduler (Omar)
- Removal of dangerous bio_rewind_iter() API (Ming)
- Apply single queue IPI redirection logic to blk-mq (Ming)
- Set of fixes and improvements for bcache (Coly et al)
- Series closing a hotplug race with sysfs group attributes (Hannes)
- Set of patches for lightnvm:
- pblk trace support (Hans)
- SPDX license header update (Javier)
- Tons of refactoring patches to cleanly abstract the 1.2 and 2.0
specs behind a common core interface. (Javier, Matias)
- Enable pblk to use a common interface to retrieve chunk metadata
(Matias)
- Bug fixes (Various)
- Set of fixes and updates to the blk IO latency target (Josef)
- blk-mq queue number updates fixes (Jianchao)
- Convert a bunch of drivers from the old legacy IO interface to
blk-mq. This will conclude with the removal of the legacy IO
interface itself in 4.21, with the rest of the drivers (me, Omar)
- Removal of the DAC960 driver. The SCSI tree will introduce two
replacement drivers for this (Hannes)"
* tag 'for-4.20/block-20181021' of git://git.kernel.dk/linux-block: (204 commits)
block: setup bounce bio_sets properly
blkcg: reassociate bios when make_request() is called recursively
blkcg: fix edge case for blk_get_rl() under memory pressure
nvme-fabrics: move controller options matching to fabrics
nvme-rdma: always have a valid trsvcid
mtip32xx: fully switch to the generic DMA API
rsxx: switch to the generic DMA API
umem: switch to the generic DMA API
sx8: switch to the generic DMA API
sx8: remove dead IF_64BIT_DMA_IS_POSSIBLE code
skd: switch to the generic DMA API
ubd: remove use of blk_rq_map_sg
nvme-pci: remove duplicate check
drivers/block: Remove DAC960 driver
nvme-pci: fix hot removal during error handling
nvmet-fcloop: suppress a compiler warning
nvme-core: make implicit seed truncation explicit
nvmet-fc: fix kernel-doc headers
nvme-fc: rework the request initialization code
nvme-fc: introduce struct nvme_fcp_op_w_sgl
...
Pull arm64 updates from Catalin Marinas:
"Apart from some new arm64 features and clean-ups, this also contains
the core mmu_gather changes for tracking the levels of the page table
being cleared and a minor update to the generic
compat_sys_sigaltstack() introducing COMPAT_SIGMINSKSZ.
Summary:
- Core mmu_gather changes which allow tracking the levels of
page-table being cleared together with the arm64 low-level flushing
routines
- Support for the new ARMv8.5 PSTATE.SSBS bit which can be used to
mitigate Spectre-v4 dynamically without trapping to EL3 firmware
- Introduce COMPAT_SIGMINSTKSZ for use in compat_sys_sigaltstack
- Optimise emulation of MRS instructions to ID_* registers on ARMv8.4
- Support for Common Not Private (CnP) translations allowing threads
of the same CPU to share the TLB entries
- Accelerated crc32 routines
- Move swapper_pg_dir to the rodata section
- Trap WFI instruction executed in user space
- ARM erratum 1188874 workaround (arch_timer)
- Miscellaneous fixes and clean-ups"
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (78 commits)
arm64: KVM: Guests can skip __install_bp_hardening_cb()s HYP work
arm64: cpufeature: Trap CTR_EL0 access only where it is necessary
arm64: cpufeature: Fix handling of CTR_EL0.IDC field
arm64: cpufeature: ctr: Fix cpu capability check for late CPUs
Documentation/arm64: HugeTLB page implementation
arm64: mm: Use __pa_symbol() for set_swapper_pgd()
arm64: Add silicon-errata.txt entry for ARM erratum 1188873
Revert "arm64: uaccess: implement unsafe accessors"
arm64: mm: Drop the unused cpu parameter
MAINTAINERS: fix bad sdei paths
arm64: mm: Use #ifdef for the __PAGETABLE_P?D_FOLDED defines
arm64: Fix typo in a comment in arch/arm64/mm/kasan_init.c
arm64: xen: Use existing helper to check interrupt status
arm64: Use daifflag_restore after bp_hardening
arm64: daifflags: Use irqflags functions for daifflags
arm64: arch_timer: avoid unused function warning
arm64: Trap WFI executed in userspace
arm64: docs: Document SSBS HWCAP
arm64: docs: Fix typos in ELF hwcaps
arm64/kprobes: remove an extra semicolon in arch_prepare_kprobe
...
When the kernel is built with:
CONFIG_PREEMPT=y
CONFIG_PREEMPT_COUNT=y
"stfle" function used by kasan initialization code makes additional
call to preempt_count_add/preempt_count_sub. To avoid removing kasan
instrumentation from sched code where those functions leave split stfle
function and provide __stfle variant without preemption handling to be
used by Kasan.
Reported-by: Benjamin Block <bblock@linux.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The following commit:
d7880812b3 ("idle: Add the stack canary init to cpu_startup_entry()")
... added an x86 specific boot_init_stack_canary() call to the generic
cpu_startup_entry() as a temporary hack, with the intention to remove
the #ifdef CONFIG_X86 later.
More than 5 years later let's finally realize that plan! :-)
While implementing stack protector support for PowerPC, we found
that calling boot_init_stack_canary() is also needed for PowerPC
which uses per task (TLS) stack canary like the X86.
However, calling boot_init_stack_canary() would break architectures
using a global stack canary (ARM, SH, MIPS and XTENSA).
Instead of modifying the #ifdef CONFIG_X86 to an even messier:
#if defined(CONFIG_X86) || defined(CONFIG_PPC)
PowerPC implemented the call to boot_init_stack_canary() in the function
calling cpu_startup_entry().
Let's try the same cleanup on the x86 side as well.
On x86 we have two functions calling cpu_startup_entry():
- start_secondary()
- cpu_bringup_and_idle()
start_secondary() already calls boot_init_stack_canary(), so
it's good, and this patch adds the call to boot_init_stack_canary()
in cpu_bringup_and_idle().
I.e. now x86 catches up to the rest of the world and the ugly init
sequence in init/main.c can be removed from cpu_startup_entry().
As a final benefit we can also remove the <linux/stackprotector.h>
dependency from <linux/sched.h>.
[ mingo: Improved the changelog a bit, added language explaining x86 borkage and sched.h change. ]
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Juergen Gross <jgross@suse.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/20181020072649.5B59310483E@pc16082vm.idsi0.si.c-s.fr
Signed-off-by: Ingo Molnar <mingo@kernel.org>
David Ahern's dump indexing bug fix in 'net' overlapped the
change of the function signature of inet6_fill_ifaddr() in
'net-next'. Trivially resolved.
Signed-off-by: David S. Miller <davem@davemloft.net>
Second PPC KVM update for 4.20.
Two commits; one is an optimization for PCI pass-through, and the
other disables nested HV-KVM on early POWER9 chips that need a
particular hardware bug workaround.
mpic_get_primary_version() is not defined when not using MPIC.
The compile error log like:
arch/powerpc/sysdev/built-in.o: In function `fsl_of_msi_probe':
fsl_msi.c:(.text+0x150c): undefined reference to `fsl_mpic_primary_get_version'
Signed-off-by: Jia Hongtao <hongtao.jia@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
Reported-by: Radu Rendec <radu.rendec@gmail.com>
Fixes: 807d38b73b ("powerpc/mpic: Add get_version API both for internal and external use")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Recently in commit 7241d26e81 ("powerpc/64: properly initialise
the stackprotector canary on SMP.") we fixed a crash with stack
protector on SMP by initialising the stack canary in
cpu_idle_thread_init().
But this can also causes crashes, when a CPU comes back online after
being offline:
Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: pnv_smp_cpu_kill_self+0x2a0/0x2b0
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.19.0-rc3-gcc-7.3.1-00168-g4ffe713b7587 #94
Call Trace:
dump_stack+0xb0/0xf4 (unreliable)
panic+0x144/0x328
__stack_chk_fail+0x2c/0x30
pnv_smp_cpu_kill_self+0x2a0/0x2b0
cpu_die+0x48/0x70
arch_cpu_idle_dead+0x20/0x40
do_idle+0x274/0x390
cpu_startup_entry+0x38/0x50
start_secondary+0x5e4/0x600
start_secondary_prolog+0x10/0x14
Looking at the stack we see that the canary value in the stack frame
doesn't match the canary in the task/paca. That is because we have
reinitialised the task/paca value, but then the CPU coming online has
returned into a function using the old canary value. That causes the
comparison to fail.
Instead we can call boot_init_stack_canary() from start_secondary()
which never returns. This is essentially what the generic code does in
cpu_startup_entry() under #ifdef X86, we should make that non-x86
specific in a future patch.
Fixes: 7241d26e81 ("powerpc/64: properly initialise the stackprotector canary on SMP.")
Reported-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
According to the T2080RDB schematics, for the CS4315 PHY, the XFI 1 lane is
connected to SFP 2 and the XFI 2 lane is connected to SFP 1. Change the
device tree to reflect the correct PHY order and port association.
Signed-off-by: Camelia Groza <camelia.groza@nxp.com>
Signed-off-by: Scott Wood <oss@buserror.net>
The attached patch implements three optimizations:
1) Loops in flush_user_dcache_range_asm, flush_kernel_dcache_range_asm,
purge_kernel_dcache_range_asm, flush_user_icache_range_asm, and
flush_kernel_icache_range_asm are unrolled to reduce branch overhead.
2) The static branch prediction for cmpb instructions in pacache.S have
been reviewed and the operand order adjusted where necessary.
3) For flush routines in cache.c, we purge rather flush when we have no
context. The pdc instruction at level 0 is not required to write back
dirty lines to memory. This provides a performance improvement over the
fdc instruction if the feature is implemented.
Version 2 adds alternative patching.
The patch provides an average improvement of about 2%.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
The attached change removes the pte_inserted from pgtable.h. As a
result, we always flush the TLB entry when the associated page table
entry is changed.
This change doesn't impact performance signifcantly and it may catch
some cases where the TLB needs flushing but wasn't.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
- Differentiate between pciehp surprise and safe removal (Lukas Wunner)
- Remove unnecessary pciehp includes (Lukas Wunner)
- Drop pciehp hotplug_slot_ops wrappers (Lukas Wunner)
- Tolerate PCIe Slot Presence Detect being hardwired to zero to
workaround broken hardware, e.g., the Wilocity switch/wireless device
(Lukas Wunner)
- Unify pciehp controller & slot structs (Lukas Wunner)
- Constify hotplug_slot_ops (Lukas Wunner)
- Drop hotplug_slot_info (Lukas Wunner)
- Embed hotplug_slot struct into users instead of allocating it
separately (Lukas Wunner)
- Initialize PCIe port service drivers directly instead of relying on
initcall ordering (Keith Busch)
- Restore PCI config state after a slot reset (Keith Busch)
- Save/restore DPC config state along with other PCI config state (Keith
Busch)
- Reference count devices during AER handling to avoid race issue with
concurrent hot removal (Keith Busch)
- If an Upstream Port reports ERR_FATAL, don't try to read the Port's
config space because it is probably unreachable (Keith Busch)
- During error handling, use slot-specific reset instead of secondary
bus reset to avoid link up/down issues on hotplug ports (Keith Busch)
- Restore previous AER/DPC handling that does not remove and re-enumerate
devices on ERR_FATAL (Keith Busch)
- Notify all drivers that may be affected by error recovery resets (Keith
Busch)
- Always generate error recovery uevents, even if a driver doesn't have
error callbacks (Keith Busch)
- Make PCIe link active reporting detection generic (Keith Busch)
- Support D3cold in PCIe hierarchies during system sleep and runtime,
including hotplug and Thunderbolt ports (Mika Westerberg)
- Handle hpmemsize/hpiosize kernel parameters uniformly, whether slots
are empty or occupied (Jon Derrick)
- Remove duplicated include from pci/pcie/err.c and unused variable from
cpqphp (YueHaibing)
- Remove driver pci_cleanup_aer_uncorrect_error_status() calls (Oza
Pawandeep)
- Uninline PCI bus accessors for better ftracing (Keith Busch)
- Remove unused AER Root Port .error_resume method (Keith Busch)
- Use kfifo in AER instead of a local version (Keith Busch)
- Use threaded IRQ in AER bottom half (Keith Busch)
- Use managed resources in AER core (Keith Busch)
- Reuse pcie_port_find_device() for AER injection (Keith Busch)
- Abstract AER interrupt handling to disconnect error injection (Keith
Busch)
- Refactor AER injection callbacks to simplify future improvments (Keith
Busch)
* pci/hotplug:
PCI/AER: Refactor error injection fallbacks
PCI/AER: Abstract AER interrupt handling
PCI/AER: Reuse existing pcie_port_find_device() interface
PCI/AER: Use managed resource allocations
PCI/AER: Use threaded IRQ for bottom half
PCI/AER: Use kfifo_in_spinlocked() to insert locked elements
PCI/AER: Use kfifo for tracking events instead of reimplementing it
PCI/AER: Remove error source from AER struct aer_rpc
PCI/AER: Remove unused aer_error_resume()
PCI: Uninline PCI bus accessors for better ftracing
PCI/AER: Remove pci_cleanup_aer_uncorrect_error_status() calls
PCI: pnv_php: Use kmemdup()
PCI: cpqphp: Remove set but not used variable 'physical_slot'
PCI/ERR: Remove duplicated include from err.c
PCI: Equalize hotplug memory and io for occupied and empty slots
PCI / ACPI: Whitelist D3 for more PCIe hotplug ports
ACPI / property: Allow multiple property compatible _DSD entries
PCI/PME: Implement runtime PM callbacks
PCI: pciehp: Implement runtime PM callbacks
PCI/portdrv: Add runtime PM hooks for port service drivers
PCI/portdrv: Resume upon exit from system suspend if left runtime suspended
PCI: pciehp: Do not handle events if interrupts are masked
PCI: pciehp: Disable hotplug interrupt during suspend
PCI / ACPI: Enable wake automatically for power managed bridges
PCI: Do not skip power-managed bridges in pci_enable_wake()
PCI: Make link active reporting detection generic
PCI: Unify device inaccessible
PCI/ERR: Always report current recovery status for udev
PCI/ERR: Simplify broadcast callouts
PCI/ERR: Run error recovery callbacks for all affected devices
PCI/ERR: Handle fatal error recovery
PCI/ERR: Use slot reset if available
PCI/AER: Don't read upstream ports below fatal errors
PCI/AER: Take reference on error devices
PCI/DPC: Save and restore config state
PCI: portdrv: Restore PCI config state on slot reset
PCI: portdrv: Initialize service drivers directly
PCI: hotplug: Document TODOs
PCI: hotplug: Embed hotplug_slot
PCI: hotplug: Drop hotplug_slot_info
PCI: hotplug: Constify hotplug_slot_ops
PCI: pciehp: Reshuffle controller struct for clarity
PCI: pciehp: Rename controller struct members for clarity
PCI: pciehp: Unify controller and slot structs
PCI: pciehp: Tolerate Presence Detect hardwired to zero
PCI: pciehp: Drop hotplug_slot_ops wrappers
PCI: pciehp: Drop unnecessary includes
PCI: pciehp: Differentiate between surprise and safe removal
PCI: Simplify disconnected marking
Ingo writes:
"x86 fixes:
It's 4 misc fixes, 3 build warning fixes and 3 comment fixes.
In hindsight I'd have left out the 3 comment fixes to make the pull
request look less scary at such a late point in the cycle. :-/"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/swiotlb: Enable swiotlb for > 4GiG RAM on 32-bit kernels
x86/fpu: Fix i486 + no387 boot crash by only saving FPU registers on context switch if there is an FPU
x86/fpu: Remove second definition of fpu in __fpu__restore_sig()
x86/entry/64: Further improve paranoid_entry comments
x86/entry/32: Clear the CS high bits
x86/boot: Add -Wno-pointer-sign to KBUILD_CFLAGS
x86/time: Correct the attribute on jiffies' definition
x86/entry: Add some paranoid entry/exit CR3 handling comments
x86/percpu: Fix this_cpu_read()
x86/tsc: Force inlining of cyc2ns bits
The powernv platform maintains 2 TCE tables for VFIO - a hardware TCE
table and a table with userspace addresses. These tables are radix trees,
we allocate indirect levels when they are written to. Since
the memory allocation is problematic in real mode, we have 2 accessors
to the entries:
- for virtual mode: it allocates the memory and it is always expected
to return non-NULL;
- fr real mode: it does not allocate and can return NULL.
Also, DMA windows can span to up to 55 bits of the address space and since
we never have this much RAM, such windows are sparse. However currently
the SPAPR TCE IOMMU driver walks through all TCEs to unpin DMA memory.
Since we maintain a userspace addresses table for VFIO which is a mirror
of the hardware table, we can use it to know which parts of the DMA
window have not been mapped and skip these so does this patch.
The bare metal systems do not have this problem as they use a bypass mode
of a PHB which maps RAM directly.
This helps a lot with sparse DMA windows, reducing the shutdown time from
about 3 minutes per 1 billion TCEs to a few seconds for 32GB sparse guest.
Just skipping the last level seems to be good enough.
As non-allocating accessor is used now in virtual mode as well, rename it
from IOMMU_TABLE_USERSPACE_ENTRY_RM (real mode) to _RO (read only).
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
commit b96672dd84 ("powerpc: Machine check interrupt is a non-
maskable interrupt") added a call to nmi_enter() at the beginning of
machine check restart exception handler. Due to that, in_interrupt()
always returns true regardless of the state before entering the
exception, and die() panics even when the system was not already in
interrupt.
This patch calls nmi_exit() before calling die() in order to restore
the interrupt state we had before calling nmi_enter()
Fixes: b96672dd84 ("powerpc: Machine check interrupt is a non-maskable interrupt")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The recent module relocation overflow crash demonstrated that we
have no range checking on REL32 relative relocations. This patch
implements a basic check, the same kernel that previously oopsed
and rebooted now continues with some of these errors when loading
the module:
module_64: x_tables: REL32 527703503449812 out of range!
Possibly other relocations (ADDR32, REL16, TOC16, etc.) should also have
overflow checks.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When we're running on Book3S with the Radix MMU enabled the page table
dump currently prints the wrong addresses because it uses the wrong
start address.
Fix it to use PAGE_OFFSET rather than KERN_VIRT_START.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
At boot we print the ranges we've mapped for the linear mapping and
what page size we've used. Also track whether the range is mapped
executable or not and display that as well.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
If we look closely at the logic in create_physical_mapping(), when
we're doing STRICT_KERNEL_RWX, we do the following steps:
- determine the gap from where we are to the end of the range
- choose an appropriate mapping_size based on the gap
- check if that mapping_size would overlap the __init_begin
boundary, and if not choose an appropriate mapping_size
We can simplify the logic by taking the __init_begin boundary into
account when we calculate the initial gap.
So add a next_boundary() function which tells us what the next
boundary is, either the __init_begin boundary or end. In future we can
add more boundaries.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When we have CONFIG_STRICT_KERNEL_RWX enabled, we want to split the
linear mapping at the text/data boundary so we can map the kernel
text read only.
The current logic uses a goto inside the for loop, which works, but is
hard to reason about.
When we hit the goto retry case we set max_mapping_size to PMD_SIZE
and go back to the start.
Setting max_mapping_size means we skip the PUD case and go to the PMD
case.
We know we will pass the alignment and gap checks because the only
reason we are there is we hit the goto retry, and that is guarded by
mapping_size == PUD_SIZE, which means addr is PUD aligned and gap is
greater or equal to PUD_SIZE.
So the only part of the check that can fail is the mmu_psize_defs
check for the 2M page size.
If we just duplicate that check we can avoid the goto, and we get the
same result.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When we have CONFIG_STRICT_KERNEL_RWX enabled, we want to split the
linear mapping at the text/data boundary so we can map the kernel
text read only.
Currently we always use a small page at the text/data boundary, even
when that's not necessary:
Mapped 0x0000000000000000-0x0000000000e00000 with 2.00 MiB pages
Mapped 0x0000000000e00000-0x0000000001000000 with 64.0 KiB pages
Mapped 0x0000000001000000-0x0000000040000000 with 2.00 MiB pages
This is because the check that the mapping crosses the __init_begin
boundary is too strict, it also returns true when we map exactly up to
the boundary.
So fix it to check that the mapping would actually map past
__init_begin, and with that we see:
Mapped 0x0000000000000000-0x0000000040000000 with 2.00 MiB pages
Mapped 0x0000000040000000-0x0000000100000000 with 1.00 GiB pages
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When we have CONFIG_STRICT_KERNEL_RWX enabled, we want to split the
linear mapping at the text/data boundary so we can map the kernel text
read only.
But the current logic uses small pages for the entire text section,
regardless of whether a larger page size would fit. eg. with the
boundary at 16M we could use 2M pages, but instead we use 64K pages up
to the 16M boundary:
Mapped 0x0000000000000000-0x0000000001000000 with 64.0 KiB pages
Mapped 0x0000000001000000-0x0000000040000000 with 2.00 MiB pages
Mapped 0x0000000040000000-0x0000000100000000 with 1.00 GiB pages
This is because the test is checking if addr is < __init_begin
and addr + mapping_size is >= _stext. But that is true for all pages
between _stext and __init_begin.
Instead what we want to check is if we are crossing the text/data
boundary, which is at __init_begin. With that fixed we see:
Mapped 0x0000000000000000-0x0000000000e00000 with 2.00 MiB pages
Mapped 0x0000000000e00000-0x0000000001000000 with 64.0 KiB pages
Mapped 0x0000000001000000-0x0000000040000000 with 2.00 MiB pages
Mapped 0x0000000040000000-0x0000000100000000 with 1.00 GiB pages
ie. we're correctly using 2MB pages below __init_begin, but we still
drop down to 64K pages unnecessarily at the boundary.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When we have CONFIG_STRICT_KERNEL_RWX enabled, we try to split the
kernel linear (1:1) mapping so that the kernel text is in a separate
page to kernel data, so we can mark the former read-only.
We could achieve that just by always using 64K pages for the linear
mapping, but we try to be smarter. Instead we use huge pages when
possible, and only switch to smaller pages when necessary.
However we have an off-by-one bug in that logic, which causes us to
calculate the wrong boundary between text and data.
For example with the end of the kernel text at 16M we see:
radix-mmu: Mapped 0x0000000000000000-0x0000000001200000 with 64.0 KiB pages
radix-mmu: Mapped 0x0000000001200000-0x0000000040000000 with 2.00 MiB pages
radix-mmu: Mapped 0x0000000040000000-0x0000000100000000 with 1.00 GiB pages
ie. we mapped from 0 to 18M with 64K pages, even though the boundary
between text and data is at 16M.
With the fix we see we're correctly hitting the 16M boundary:
radix-mmu: Mapped 0x0000000000000000-0x0000000001000000 with 64.0 KiB pages
radix-mmu: Mapped 0x0000000001000000-0x0000000040000000 with 2.00 MiB pages
radix-mmu: Mapped 0x0000000040000000-0x0000000100000000 with 1.00 GiB pages
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently, we expect to be able to reach ftrace_caller() from all
ftrace-enabled functions through a single relative branch. With large
kernel configs, we see functions outside of 32MB of ftrace_caller()
causing ftrace_init() to bail.
In such configurations, gcc/ld emits two types of trampolines for mcount():
1. A long_branch, which has a single branch to mcount() for functions that
are one hop away from mcount():
c0000000019e8544 <00031b56.long_branch._mcount>:
c0000000019e8544: 4a 69 3f ac b c00000000007c4f0 <._mcount>
2. A plt_branch, for functions that are farther away from mcount():
c0000000051f33f8 <0008ba04.plt_branch._mcount>:
c0000000051f33f8: 3d 82 ff a4 addis r12,r2,-92
c0000000051f33fc: e9 8c 04 20 ld r12,1056(r12)
c0000000051f3400: 7d 89 03 a6 mtctr r12
c0000000051f3404: 4e 80 04 20 bctr
We can reuse those trampolines for ftrace if we can have those
trampolines go to ftrace_caller() instead. However, with ABIv2, we
cannot depend on r2 being valid. As such, we use only the long_branch
trampolines by patching those to instead branch to ftrace_caller or
ftrace_regs_caller.
In addition, we add additional trampolines around .text and .init.text
to catch locations that are covered by the plt branches. This allows
ftrace to work with most large kernel configurations.
For now, we always patch the trampolines to go to ftrace_regs_caller,
which is slightly inefficient. This can be optimized further at a later
point.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
If CONFIG_PPC_SPLPAR is not selected, steal_time will always
be NUL, so accounting it is pointless
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
scaled cputime is only meaningfull when the processor has
SPURR and/or PURR, which means only on PPC64.
Removing it on PPC32 significantly reduces the size of
vtime_account_system() and vtime_account_idle() on an 8xx:
Before:
00000000 l F .text 000000a8 vtime_delta
00000280 g F .text 0000010c vtime_account_system
0000038c g F .text 00000048 vtime_account_idle
After:
(vtime_delta gets inlined inside the two functions)
000001d8 g F .text 000000a0 vtime_account_system
00000278 g F .text 00000038 vtime_account_idle
In terms of performance, we also get approximatly 7% improvement on
task switch. The following small benchmark app is run with perf stat:
void *thread(void *arg)
{
int i;
for (i = 0; i < atoi((char*)arg); i++)
pthread_yield();
}
int main(int argc, char **argv)
{
pthread_t th1, th2;
pthread_create(&th1, NULL, thread, argv[1]);
pthread_create(&th2, NULL, thread, argv[1]);
pthread_join(th1, NULL);
pthread_join(th2, NULL);
return 0;
}
Before the patch:
Performance counter stats for 'chrt -f 98 ./sched 100000' (50 runs):
8228.476465 task-clock (msec) # 0.954 CPUs utilized ( +- 0.23% )
200004 context-switches # 0.024 M/sec ( +- 0.00% )
After the patch:
Performance counter stats for 'chrt -f 98 ./sched 100000' (50 runs):
7649.070444 task-clock (msec) # 0.955 CPUs utilized ( +- 0.27% )
200004 context-switches # 0.026 M/sec ( +- 0.00% )
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
scaled cputime is only meaningfull when the processor has
SPURR and/or PURR, which means only on PPC64.
In preparation of the following patch that will remove
CONFIG_ARCH_HAS_SCALED_CPUTIME on PPC32, this patch moves
all scaled cputing accounting logic into dedicated functions.
This patch doesn't change any functionality. It's only code
reorganisation.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
ipic_get_mcp_status() is used by targets implementing NMI
watchdog in target specific machine check handler in order
to known whether a machine check results from a watchdog
NMI reset.
In case of very early machine check, primary_ipic pointer
might not have been set yet, so ipic_get_mcp_status() needs
to check it for nullity before using it.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch fixes the following warnings (obtained with make W=1).
arch/powerpc/mm/slice.c: In function 'slice_range_to_mask':
arch/powerpc/mm/slice.c:73:12: error: comparison is always true due to limited range of data type [-Werror=type-limits]
if (start < SLICE_LOW_TOP) {
^
arch/powerpc/mm/slice.c:81:20: error: comparison is always false due to limited range of data type [-Werror=type-limits]
if ((start + len) > SLICE_LOW_TOP) {
^
arch/powerpc/mm/slice.c: In function 'slice_mask_for_free':
arch/powerpc/mm/slice.c:136:17: error: comparison is always true due to limited range of data type [-Werror=type-limits]
if (high_limit <= SLICE_LOW_TOP)
^
arch/powerpc/mm/slice.c: In function 'slice_check_range_fits':
arch/powerpc/mm/slice.c:185:12: error: comparison is always true due to limited range of data type [-Werror=type-limits]
if (start < SLICE_LOW_TOP) {
^
arch/powerpc/mm/slice.c:195:39: error: comparison is always false due to limited range of data type [-Werror=type-limits]
if (SLICE_NUM_HIGH && ((start + len) > SLICE_LOW_TOP)) {
^
arch/powerpc/mm/slice.c: In function 'slice_scan_available':
arch/powerpc/mm/slice.c:306:11: error: comparison is always true due to limited range of data type [-Werror=type-limits]
if (addr < SLICE_LOW_TOP) {
^
arch/powerpc/mm/slice.c: In function 'get_slice_psize':
arch/powerpc/mm/slice.c:709:11: error: comparison is always true due to limited range of data type [-Werror=type-limits]
if (addr < SLICE_LOW_TOP) {
^
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch fixes the following warnings (obtained with make W=1).
arch/powerpc/mm/slice.c: At top level:
arch/powerpc/mm/slice.c:682:15: error: no previous prototype for 'arch_get_unmapped_area' [-Werror=missing-prototypes]
unsigned long arch_get_unmapped_area(struct file *filp,
^
arch/powerpc/mm/slice.c:692:15: error: no previous prototype for 'arch_get_unmapped_area_topdown' [-Werror=missing-prototypes]
unsigned long arch_get_unmapped_area_topdown(struct file *filp,
^
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Add a trace point for tlbia (Translation Lookaside Buffer Invalidate
All) instruction.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Since commit bd0dbb73e0 ("powerpc/mm/books3s: Add new pte bit to
mark pte temporarily invalid."), _PAGE_PRESENT doesn't mean exactly
that a page is present. A page is also considered preset when
_PAGE_INVALID is set.
This patch changes the meaning of "present" and adds a status "valid"
associated to the _PAGE_PRESENT flag.
Fixes: bd0dbb73e0 ("powerpc/mm/books3s: Add new pte bit to mark pte temporarily invalid.")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch exports the raw per-CPU VPA data via debugfs.
A per-CPU file is created which exports the VPA data of
that CPU to help debug some of the VPA related issues or
to analyze the per-CPU VPA related statistics.
v3: Removed offline CPU check.
v2: Included offline CPU check and other review comments.
Signed-off-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
