Modify the base address of the mdio mux driver to point to the
start of the mdio mux block's register address space.
Signed-off-by: Arun Parameswaran <arun.parameswaran@broadcom.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The BTF conflicts were simple overlapping changes.
The virtio_net conflict was an overlap of a fix of statistics counter,
happening alongisde a move over to a bonafide statistics structure
rather than counting value on the stack.
Signed-off-by: David S. Miller <davem@davemloft.net>
- Fix potential clobbering of user vector register state by AES ghash code
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Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 regression fix from Will Deacon:
"Ard found a nasty arm64 regression in 4.18 where the AES ghash/gcm
code doesn't notify the kernel about its use of the vector registers,
therefore potentially corrupting live user state.
The fix is straightforward and Herbert agreed for it to go via arm64"
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
crypto/arm64: aes-ce-gcm - add missing kernel_neon_begin/end pair
generic_defconfig explicitly disables CONFIG_INPUT_MOUSEDEV,
CONFIG_INPUT_KEYBOARD & CONFIG_INPUT_MOUSE which results in warnings
when merging board config fragments if any of them require these
options. This is the case for the ranchu board, which means we've had
the following warning when configuring for generic platform targets
since commit f2d0b0d5c171 ("MIPS: ranchu: Add Ranchu as a new
generic-based board"):
$ make ARCH=mips 32r2el_defconfig
Using ./arch/mips/configs/generic_defconfig as base
Merging arch/mips/configs/generic/32r2.config
Merging arch/mips/configs/generic/el.config
Merging ./arch/mips/configs/generic/board-sead-3.config
Merging ./arch/mips/configs/generic/board-ranchu.config
Value of CONFIG_INPUT_KEYBOARD is redefined by fragment ./arch/mips/configs/generic/board-ranchu.config:
Previous value: # CONFIG_INPUT_KEYBOARD is not set
New value: CONFIG_INPUT_KEYBOARD=y
Merging ./arch/mips/configs/generic/board-ni169445.config
Merging ./arch/mips/configs/generic/board-boston.config
Merging ./arch/mips/configs/generic/board-ocelot.config
Merging ./arch/mips/configs/generic/board-xilfpga.config
scripts/kconfig/conf --olddefconfig Kconfig
#
# configuration written to .config
#
Resolve this by removing mention of the CONFIG_INPUT_* Kconfig symbols
from generic_defconfig, allowing them to take their default values &
allowing board config fragments to enable them without warnings.
This may be problematic if CONFIG_ARCH_MIGHT_HAVE_PC_SERIO is ever
enabled for CONFIG_MIPS_GENERIC=y configurations, but for now that isn't
the case so we can worry about that if & when it happens.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/20109/
Cc: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Spectre variant 1 attacks are about this sequence of pseudo-code:
index = load(user-manipulated pointer);
access(base + index * stride);
In order for the cache side-channel to work, the access() must me made
to memory which userspace can detect whether cache lines have been
loaded. On 32-bit ARM, this must be either user accessible memory, or
a kernel mapping of that same user accessible memory.
The problem occurs when the load() speculatively loads privileged data,
and the subsequent access() is made to user accessible memory.
Any load() which makes use of a user-maniplated pointer is a potential
problem if the data it has loaded is used in a subsequent access. This
also applies for the access() if the data loaded by that access is used
by a subsequent access.
Harden the get_user() accessors against Spectre attacks by forcing out
of bounds addresses to a NULL pointer. This prevents get_user() being
used as the load() step above. As a side effect, put_user() will also
be affected even though it isn't implicated.
Also harden copy_from_user() by redoing the bounds check within the
arm_copy_from_user() code, and NULLing the pointer if out of bounds.
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Fixing __get_user() for spectre variant 1 is not sane: we would have to
add address space bounds checking in order to validate that the location
should be accessed, and then zero the address if found to be invalid.
Since __get_user() is supposed to avoid the bounds check, and this is
exactly what get_user() does, there's no point having two different
implementations that are doing the same thing. So, when the Spectre
workarounds are required, make __get_user() an alias of get_user().
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Borrow the x86 implementation of __inttype() to use in get_user() to
select an integer type suitable to temporarily hold the result value.
This is necessary to avoid propagating the volatile nature of the
result argument, which can cause the following warning:
lib/iov_iter.c:413:5: warning: optimization may eliminate reads and/or writes to register variables [-Wvolatile-register-var]
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
__get_user_error() is used as a fast accessor to make copying structure
members as efficient as possible. However, with software PAN and the
recent Spectre variant 1, the efficiency is reduced as these are no
longer fast accessors.
In the case of software PAN, it has to switch the domain register around
each access, and with Spectre variant 1, it would have to repeat the
access_ok() check for each access.
Rather than using __get_user_error() to copy each semops element member,
copy each semops element in full using __copy_from_user().
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
__get_user_error() is used as a fast accessor to make copying structure
members in the signal handling path as efficient as possible. However,
with software PAN and the recent Spectre variant 1, the efficiency is
reduced as these are no longer fast accessors.
In the case of software PAN, it has to switch the domain register around
each access, and with Spectre variant 1, it would have to repeat the
access_ok() check for each access.
Use __copy_from_user() rather than __get_user_err() for individual
members when restoring VFP state.
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
The check for p == q is dead code because the proceeding switch
statements jump to the end of the outer for-loop with continue
statements. Remove the dead code.
Detected by CoverityScan, CID#145071 ("Structurally dead code")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: kernel-janitors@vger.kernel.org
Link: https://lkml.kernel.org/r/20180731090938.11856-1-colin.king@canonical.com
There were two report of boot failure cased by trampoline placed into
a reserved memory region. It can happen on machines that don't report
EBDA correctly.
Fix the problem by re-validating the found address against the E820 table.
If the address is in a reserved area, find the next usable region below the
initial address.
Fixes: 3548e131ec6a ("x86/boot/compressed/64: Find a place for 32-bit trampoline")
Reported-by: Dmitry Malkin <d.malkin@real-time-systems.com>
Reported-by: youling 257 <youling257@gmail.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lkml.kernel.org/r/20180801133225.38121-1-kirill.shutemov@linux.intel.com
Switch to the generic noncoherent direct mapping implementation.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Yoshinori Sato <ysato@users.sourceforge.jp>
Half of the file just contains platform device memory setup code which
is required for all builds, and half contains helpers for dma coherent
allocation, which is only needed if CONFIG_DMA_NONCOHERENT is enabled.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Yoshinori Sato <ysato@users.sourceforge.jp>
This is a slight change in behavior as we avoid the detour through the
virtual mapping for the coherent allocator, but if this CPU really is
coherent that should be the right thing to do.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Yoshinori Sato <ysato@users.sourceforge.jp>
And use it in the maple bus code to avoid a dma API dependency.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Yoshinori Sato <ysato@users.sourceforge.jp>
Remove the indirection through the dma_ops variable, and just return
nommu_dma_ops directly from get_arch_dma_ops.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Yoshinori Sato <ysato@users.sourceforge.jp>
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 <rdunlap@infradead.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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 <hch@lst.de>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Move the source of lib/Kconfig.debug and arch/$(ARCH)/Kconfig.debug to
the top-level Kconfig. For two architectures that means moving their
arch-specific symbols in that menu into a new arch Kconfig.debug file,
and for a few more creating a dummy file so that we can include it
unconditionally.
Also move the actual 'Kernel hacking' menu to lib/Kconfig.debug, where
it belongs.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Instead of duplicating the source statements in every architecture just
do it once in the toplevel Kconfig file.
Note that with this the inclusion of arch/$(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 <hch@lst.de>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
microblaze and nios2 define their own always n SWAP symbols. Remove those
and let the generic defintion do the right thing by adding a new symbol
to disable swap entirely.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Merge arch/um/Kconfig.char and arch/um/Kconfig.net into a new
arch/um/drivers/Kconfig. This fits the way Kconfig files are placed
elsewhere in the kernel tree.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
We can handle all not architecture specific UM configuration directly in
the newly added arch/um/Kconfig. Do so by merging the Kconfig.common,
Kconfig.rest and Kconfig.um files into arch/um/Kconfig, and move the main
UML menu as well.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Instead create a arch/um/Kconfig file that just includes the actual
per-arch Kconfig file. Note that we use HEADER_ARCH to find the
per-arch Kconfig file as that variable already includes the
normalization from i386 or x86_64 to x86.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Pull ARM fix from Russell King:
"Just a single fix this time around for recent binutils causing build
problems when generating Thumb-2 code"
* 'fixes' of git://git.armlinux.org.uk/~rmk/linux-arm:
ARM: 8781/1: Fix Thumb-2 syscall return for binutils 2.29+
Commit 2c4541e24c55 ("mm: use vma_init() to initialize VMAs on stack and
data segments") tried to initialize various left-over ad-hoc vma's
"properly", but actually made things worse for the temporary vma's used
for TLB flushing.
vma_init() doesn't actually initialize all of the vma, just a few
fields, so doing something like
- struct vm_area_struct vma = { .vm_mm = tlb->mm, };
+ struct vm_area_struct vma;
+
+ vma_init(&vma, tlb->mm);
was actually very bad: instead of having a nicely initialized vma with
every field but "vm_mm" zeroed, you'd have an entirely uninitialized vma
with only a couple of fields initialized. And they weren't even fields
that the code in question mostly cared about.
The flush_tlb_range() function takes a "struct vma" rather than a
"struct mm_struct", because a few architectures actually care about what
kind of range it is - being able to only do an ITLB flush if it's a
range that doesn't have data accesses enabled, for example. And all the
normal users already have the vma for doing the range invalidation.
But a few people want to call flush_tlb_range() with a range they just
made up, so they also end up using a made-up vma. x86 just has a
special "flush_tlb_mm_range()" function for this, but other
architectures (arm and ia64) do the "use fake vma" thing instead, and
thus got caught up in the vma_init() changes.
At the same time, the TLB flushing code really doesn't care about most
other fields in the vma, so vma_init() is just unnecessary and
pointless.
This fixes things by having an explicit "this is just an initializer for
the TLB flush" initializer macro, which is used by the arm/arm64/ia64
people who mis-use this interface with just a dummy vma.
Fixes: 2c4541e24c55 ("mm: use vma_init() to initialize VMAs on stack and data segments")
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The A() & AA() macros have been unused since commit 05e4396651ca
("[MIPS] Use SYSVIPC_COMPAT to fix various problems on N32"), which
switched to the more standard compat_ptr().
RLIM_INFINITY32, RESOURCE32() & struct rlimit32 have been present but
unused since the beginning of the git era.
Remove the dead code.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/20108/
Cc: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
The sys_32_mmap2 function has been unused since we started using syscall
wrappers in commit dbda6ac08976 ("MIPS: CVE-2009-0029: Enable syscall
wrappers."), and is indeed identical to the sys_mips_mmap2 function that
replaced it in sys32_call_table.
Remove the dead code.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/20107/
Cc: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Our sigreturn functions make use of a macro named nabi_no_regargs to
declare 8 dummy arguments to a function, forcing the compiler to expect
a pt_regs structure on the stack rather than in argument registers. This
is an ugly hack which unnecessarily causes these sigreturn functions to
need to care about the calling convention of the ABI the kernel is built
for. Although this is abstracted via nabi_no_regargs, it's still ugly &
unnecessary.
Remove nabi_no_regargs & the struct pt_regs argument from sigreturn
functions, and instead use current_pt_regs() to find the struct pt_regs
on the stack, which works cleanly regardless of ABI.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/20106/
Cc: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Commit bfd40eaff5ab ("mm: fix vma_is_anonymous() false-positives") made
newly allocated vma's have a dummy vm_ops field so that they wouldn't be
mistaken for anonymous mappings, and if you wanted an anonymous vma you
had to explicitly say so by calling "vma_set_anonymous()" on it.
However, it missed the two special vmas that ia64 processes have: the
register backing store and the NaT page. So they wouldn't actually act
like anonymous ranges, and page faults on them caused a SIGBUS rather
than the creation of a new anon page in them.
That obviously will make any ia64 binary very unhappy indeed, and the
boot fails early.
Fixes: bfd40eaff5ab ("mm: fix vma_is_anonymous() false-positives")
Reported-by: Tony Luck <tony.luck@intel.com>
Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With the optimizations for TLB invalidation from commit 0cef77c7798a
("powerpc/64s/radix: flush remote CPUs out of single-threaded
mm_cpumask"), the scope of a TLBI (global vs. local) can now be
influenced by the value of the 'copros' counter of the memory context.
When calling mm_context_remove_copro(), the 'copros' counter is
decremented first before flushing. It may have the unintended side
effect of sending local TLBIs when we explicitly need global
invalidations in this case. Thus breaking any nMMU user in a bad and
unpredictable way.
Fix it by flushing first, before updating the 'copros' counter, so
that invalidations will be global.
Fixes: 0cef77c7798a ("powerpc/64s/radix: flush remote CPUs out of single-threaded mm_cpumask")
Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Tested-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The numa_init_early initcall sets the node_to_cpumask_map[0] to the
full cpu_possible_mask. Unfortunately this early_initcall is too late,
the NUMA setup for numa=emu is done even earlier. The order of calls
is numa_setup() -> emu_update_cpu_topology(), then the early_initcalls(),
followed by sched_init_domains().
Starting with git commit 051f3ca02e46432c0965e8948f00c07d8a2f09c0
"sched/topology: Introduce NUMA identity node sched domain"
the incorrect node_to_cpumask_map[0] really screws up the domain
setup and the kernel panics with the follow oops:
Cc: <stable@vger.kernel.org> # v4.15+
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
When a PCI device is detected, pdev->is_added is set to 1 and proc and
sysfs entries are created.
When the device is removed, pdev->is_added is checked for one and then
device is detached with clearing of proc and sys entries and at end,
pdev->is_added is set to 0.
is_added and is_busmaster are bit fields in pci_dev structure sharing same
memory location.
A strange issue was observed with multiple removal and rescan of a PCIe
NVMe device using sysfs commands where is_added flag was observed as zero
instead of one while removing device and proc,sys entries are not cleared.
This causes issue in later device addition with warning message
"proc_dir_entry" already registered.
Debugging revealed a race condition between the PCI core setting the
is_added bit in pci_bus_add_device() and the NVMe driver reset work-queue
setting the is_busmaster bit in pci_set_master(). As these fields are not
handled atomically, that clears the is_added bit.
Move the is_added bit to a separate private flag variable and use atomic
functions to set and retrieve the device addition state. This avoids the
race because is_added no longer shares a memory location with is_busmaster.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=200283
Signed-off-by: Hari Vyas <hari.vyas@broadcom.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Before the memory for the elfcorehdr is allocated the required size is
estimated with
alloc_size = 0x1000 + get_cpu_cnt() * 0x4a0 +
mem_chunk_cnt * sizeof(Elf64_Phdr);
Where 0x4a0 is used as size for the ELF notes to store the register
contend. This size is 8 bytes too small. Usually this does not immediately
cause a problem because the page reserved for overhead (Elf_Ehdr,
vmcoreinfo, etc.) is pretty generous. So usually there is enough spare
memory to counter the mis-calculated per cpu size. However, with growing
overhead and/or a huge cpu count the allocated size gets too small for the
elfcorehdr. Ultimately a BUG_ON is triggered causing the crash kernel to
panic.
Fix this by properly calculating the required size instead of relying on
magic numbers.
Fixes: a62bc07392539 ("s390/kdump: add support for vector extension")
Signed-off-by: Philipp Rudo <prudo@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Calling pmull_gcm_encrypt_block() requires kernel_neon_begin() and
kernel_neon_end() to be used since the routine touches the NEON
register file. Add the missing calls.
Also, since NEON register contents are not preserved outside of
a kernel mode NEON region, pass the key schedule array again.
Fixes: 7c50136a8aba ("crypto: arm64/aes-ghash - yield NEON after every ...")
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Now that we understand the deadlock arising from flush_icache_range()
on the kexec crash kernel path, add a comment to justify the use of
__flush_icache_range() here.
Reported-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
The SDEI stack helper functions are only used by _on_sdei_stack() and
refer to symbols (e.g. sdei_stack_normal_ptr) that are only defined if
CONFIG_VMAP_STACK=y.
Mark these functions as static, so we don't run into errors at link-time
due to references to undefined symbols. Stick all the parameters onto
the same line whilst we're passing through.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Include KASLR offset in arm64 VMCOREINFO ELF notes to assist in
debugging. vmcore parsing in user-space already expects this value in
the notes and we are providing it for portability of those existing
tools with x86.
Ideally we would like core code to do this (so that way this
information won't be missed when an architecture adds KASLR support),
but mips has CONFIG_RANDOMIZE_BASE, and doesn't provide kaslr_offset(),
so I am not sure if this is needed for mips (and other such similar arch
cases in future). So, lets keep this architecture specific for now.
As an example of a user-space use-case, consider the
makedumpfile user-space utility which will need fixup to use this
KASLR offset to work with cases where we need to find a way to
translate symbol address from vmlinux to kernel run time address
in case of KASLR boot on arm64.
I have already submitted the makedumpfile user-space patch upstream
and the maintainer has suggested to wait for the kernel changes to be
included (see [0]).
I tested this on my qualcomm amberwing board both for KASLR and
non-KASLR boot cases:
Without this patch:
# cat > scrub.conf << EOF
[vmlinux]
erase jiffies
erase init_task.utime
for tsk in init_task.tasks.next within task_struct:tasks
erase tsk.utime
endfor
EOF
# makedumpfile --split -d 31 -x vmlinux --config scrub.conf vmcore dumpfile_{1,2,3}
readpage_elf: Attempt to read non-existent page at 0xffffa8a5bf180000.
readmem: type_addr: 1, addr:ffffa8a5bf180000, size:8
vaddr_to_paddr_arm64: Can't read pgd
readmem: Can't convert a virtual address(ffff0000092a542c) to physical
address.
readmem: type_addr: 0, addr:ffff0000092a542c, size:390
check_release: Can't get the address of system_utsname
After this patch check_release() is ok, and also we are able to erase
symbol from vmcore (I checked this with kernel 4.18.0-rc4+):
# makedumpfile --split -d 31 -x vmlinux --config scrub.conf vmcore dumpfile_{1,2,3}
The kernel version is not supported.
The makedumpfile operation may be incomplete.
Checking for memory holes : [100.0 %] \
Checking for memory holes : [100.0 %] |
Checking foExcluding unnecessary pages : [100.0 %]
\
Excluding unnecessary pages : [100.0 %] \
The dumpfiles are saved to dumpfile_1, dumpfile_2, and dumpfile_3.
makedumpfile Completed.
[0] https://www.spinics.net/lists/kexec/msg21195.html
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Acked-by: James Morse <james.morse@arm.com>
Signed-off-by: Bhupesh Sharma <bhsharma@redhat.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
It is useful to get the running time of a thread. Doing so in an
efficient manner can be important for performance of user applications.
Avoiding system calls in `clock_gettime` when handling
CLOCK_THREAD_CPUTIME_ID is important. Other clocks are handled in the
VDSO, but CLOCK_THREAD_CPUTIME_ID falls back on the system call.
CLOCK_THREAD_CPUTIME_ID is not handled in the VDSO since it would have
costs associated with maintaining updated user space accessible time
offsets. These offsets have to be updated everytime the a thread is
scheduled/descheduled. However, for programs regularly checking the
running time of a thread, this is a performance improvement.
This patch takes a middle ground, and adds support for cap_user_time an
optional feature of the perf_event API. This way costs are only
incurred when the perf_event api is enabled. This is done the same way
as it is in x86.
Ultimately this allows calculating the thread running time in userspace
on aarch64 as follows (adapted from perf_event_open manpage):
u32 seq, time_mult, time_shift;
u64 running, count, time_offset, quot, rem, delta;
struct perf_event_mmap_page *pc;
pc = buf; // buf is the perf event mmaped page as documented in the API.
if (pc->cap_usr_time) {
do {
seq = pc->lock;
barrier();
running = pc->time_running;
count = readCNTVCT_EL0(); // Read ARM hardware clock.
time_offset = pc->time_offset;
time_mult = pc->time_mult;
time_shift = pc->time_shift;
barrier();
} while (pc->lock != seq);
quot = (count >> time_shift);
rem = count & (((u64)1 << time_shift) - 1);
delta = time_offset + quot * time_mult +
((rem * time_mult) >> time_shift);
running += delta;
// running now has the current nanosecond level thread time.
}
Summary of changes in the patch:
For aarch64 systems, make arch_perf_update_userpage update the timing
information stored in the perf_event page. Requiring the following
calculations:
- Calculate the appropriate time_mult, and time_shift factors to convert
ticks to nano seconds for the current clock frequency.
- Adjust the mult and shift factors to avoid shift factors of 32 bits.
(possibly unnecessary)
- The time_offset userspace should apply when doing calculations:
negative the current sched time (now), because time_running and
time_enabled fields of the perf_event page have just been updated.
Toggle bits to appropriate values:
- Enable cap_user_time
Signed-off-by: Michael O'Farrell <micpof@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
When kernel mode NEON was first introduced to the arm64 kernel,
every call to kernel_neon_begin()/_end() stacked resp. unstacked
the entire NEON register file, making it worthwile to reduce the
number of used NEON registers to a bare minimum, and only stack
those. kernel_neon_begin_partial() was introduced for this purpose,
but after the refactoring for SVE and other changes, it no longer
exists and was simply #define'd to kernel_neon_begin() directly.
In the mean time, all users have been updated, so let's remove
the fallback macro.
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
