linux.git/arch/arm64/kernel/process.c, branch v5.9

cpuidle: Move trace_cpu_idle() into generic code

2020-08-26T10:41:54+00:00

Remove trace_cpu_idle() from the arch_cpu_idle() implementations and
put it in the generic code, right before disabling RCU. Gets rid of
more trace_*_rcuidle() users.

Signed-off-by: Peter Zijlstra (Intel) 
Reviewed-by: Steven Rostedt (VMware) 
Reviewed-by: Thomas Gleixner 
Acked-by: Rafael J. Wysocki 
Tested-by: Marco Elver 
Link: https://lkml.kernel.org/r/20200821085348.428433395@infradead.org

arm64: Move handling of erratum 1418040 into C code

2020-08-21T10:39:56+00:00

Instead of dealing with erratum 1418040 on each entry and exit,
let's move the handling to __switch_to() instead, which has
several advantages:

- It can be applied when it matters (switching between 32 and 64
  bit tasks).
- It is written in C (yay!)
- It can rely on static keys rather than alternatives

Signed-off-by: Marc Zyngier 
Tested-by: Sai Prakash Ranjan 
Reviewed-by: Stephen Boyd 
Acked-by: Will Deacon 
Link: https://lore.kernel.org/r/20200731173824.107480-2-maz@kernel.org
Signed-off-by: Catalin Marinas

arch: rename copy_thread_tls() back to copy_thread()

2020-07-04T21:41:37+00:00

Now that HAVE_COPY_THREAD_TLS has been removed, rename copy_thread_tls()
back simply copy_thread(). It's a simpler name, and doesn't imply that only
tls is copied here. This finishes an outstanding chunk of internal process
creation work since we've added clone3().

Cc: linux-arch@vger.kernel.org
Acked-by: Thomas Bogendoerfer A
Acked-by: Stafford Horne 
Acked-by: Greentime Hu 
Acked-by: Geert Uytterhoeven A
Reviewed-by: Kees Cook 
Signed-off-by: Christian Brauner

arm64: add loglvl to dump_backtrace()

2020-06-09T16:39:11+00:00

Currently, the log-level of show_stack() depends on a platform
realization.  It creates situations where the headers are printed with
lower log level or higher than the stacktrace (depending on a platform or
user).

Furthermore, it forces the logic decision from user to an architecture
side.  In result, some users as sysrq/kdb/etc are doing tricks with
temporary rising console_loglevel while printing their messages.  And in
result it not only may print unwanted messages from other CPUs, but also
omit printing at all in the unlucky case where the printk() was deferred.

Introducing log-level parameter and KERN_UNSUPPRESSED [1] seems an easier
approach than introducing more printk buffers.  Also, it will consolidate
printings with headers.

Add log level argument to dump_backtrace() as a preparation for
introducing show_stack_loglvl().

[1]: https://lore.kernel.org/lkml/20190528002412.1625-1-dima@arista.com/T/#u

Signed-off-by: Dmitry Safonov 
Signed-off-by: Andrew Morton 
Cc: Catalin Marinas 
Cc: Russell King 
Cc: Will Deacon 
Link: http://lkml.kernel.org/r/20200418201944.482088-10-dima@arista.com
Signed-off-by: Linus Torvalds

Merge branch 'for-next/bti-user' into for-next/bti

2020-05-05T14:15:58+00:00

Merge in user support for Branch Target Identification, which narrowly
missed the cut for 5.7 after a late ABI concern.

* for-next/bti-user:
  arm64: bti: Document behaviour for dynamically linked binaries
  arm64: elf: Fix allnoconfig kernel build with !ARCH_USE_GNU_PROPERTY
  arm64: BTI: Add Kconfig entry for userspace BTI
  mm: smaps: Report arm64 guarded pages in smaps
  arm64: mm: Display guarded pages in ptdump
  KVM: arm64: BTI: Reset BTYPE when skipping emulated instructions
  arm64: BTI: Reset BTYPE when skipping emulated instructions
  arm64: traps: Shuffle code to eliminate forward declarations
  arm64: unify native/compat instruction skipping
  arm64: BTI: Decode BYTPE bits when printing PSTATE
  arm64: elf: Enable BTI at exec based on ELF program properties
  elf: Allow arch to tweak initial mmap prot flags
  arm64: Basic Branch Target Identification support
  ELF: Add ELF program property parsing support
  ELF: UAPI and Kconfig additions for ELF program properties

Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

2020-03-31T17:05:01+00:00

Pull arm64 updates from Catalin Marinas:
 "The bulk is in-kernel pointer authentication, activity monitors and
  lots of asm symbol annotations. I also queued the sys_mremap() patch
  commenting the asymmetry in the address untagging.

  Summary:

   - In-kernel Pointer Authentication support (previously only offered
     to user space).

   - ARM Activity Monitors (AMU) extension support allowing better CPU
     utilisation numbers for the scheduler (frequency invariance).

   - Memory hot-remove support for arm64.

   - Lots of asm annotations (SYM_*) in preparation for the in-kernel
     Branch Target Identification (BTI) support.

   - arm64 perf updates: ARMv8.5-PMU 64-bit counters, refactoring the
     PMU init callbacks, support for new DT compatibles.

   - IPv6 header checksum optimisation.

   - Fixes: SDEI (software delegated exception interface) double-lock on
     hibernate with shared events.

   - Minor clean-ups and refactoring: cpu_ops accessor,
     cpu_do_switch_mm() converted to C, cpufeature finalisation helper.

   - sys_mremap() comment explaining the asymmetric address untagging
     behaviour"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (81 commits)
  mm/mremap: Add comment explaining the untagging behaviour of mremap()
  arm64: head: Convert install_el2_stub to SYM_INNER_LABEL
  arm64: Introduce get_cpu_ops() helper function
  arm64: Rename cpu_read_ops() to init_cpu_ops()
  arm64: Declare ACPI parking protocol CPU operation if needed
  arm64: move kimage_vaddr to .rodata
  arm64: use mov_q instead of literal ldr
  arm64: Kconfig: verify binutils support for ARM64_PTR_AUTH
  lkdtm: arm64: test kernel pointer authentication
  arm64: compile the kernel with ptrauth return address signing
  kconfig: Add support for 'as-option'
  arm64: suspend: restore the kernel ptrauth keys
  arm64: __show_regs: strip PAC from lr in printk
  arm64: unwind: strip PAC from kernel addresses
  arm64: mask PAC bits of __builtin_return_address
  arm64: initialize ptrauth keys for kernel booting task
  arm64: initialize and switch ptrauth kernel keys
  arm64: enable ptrauth earlier
  arm64: cpufeature: handle conflicts based on capability
  arm64: cpufeature: Move cpu capability helpers inside C file
  ...

arm64: Use reboot_cpu instead of hardconding it to 0

2020-03-25T11:59:33+00:00

Use `reboot_cpu` variable instead of hardcoding 0 as the reboot cpu in
machine_shutdown().

Signed-off-by: Qais Yousef 
Signed-off-by: Thomas Gleixner 
Acked-by: Catalin Marinas 
Cc: Will Deacon 
Link: https://lkml.kernel.org/r/20200323135110.30522-8-qais.yousef@arm.com

arm64: Don't use disable_nonboot_cpus()

2020-03-25T11:59:33+00:00

disable_nonboot_cpus() is not safe to use when doing machine_down(),
because it relies on freeze_secondary_cpus() which in turn is
a suspend/resume related freeze and could abort if the logic detects any
pending activities that can prevent finishing the offlining process.

Beside disable_nonboot_cpus() is dependent on CONFIG_PM_SLEEP_SMP which
is an othogonal config to rely on to ensure this function works
correctly.

Signed-off-by: Qais Yousef 
Signed-off-by: Thomas Gleixner 
Acked-by: Catalin Marinas 
Cc: Will Deacon 
Link: https://lkml.kernel.org/r/20200323135110.30522-7-qais.yousef@arm.com

arm64: bti: Document behaviour for dynamically linked binaries

2020-03-25T09:56:10+00:00

For dynamically linked binaries the interpreter is responsible for setting
PROT_BTI on everything except itself. The dynamic linker needs to be aware
of PROT_BTI, for example in order to avoid dropping that when marking
executable pages read only after doing relocations, and doing everything
in userspace ensures that we don't get any issues due to divergences in
behaviour between the kernel and dynamic linker within a single executable.
Add a comment indicating that this is intentional to the code to help
people trying to understand what's going on.

Signed-off-by: Mark Brown 
Signed-off-by: Catalin Marinas

arm64: __show_regs: strip PAC from lr in printk

2020-03-18T09:50:20+00:00

lr is printed with %pS which will try to find an entry in kallsyms.
After enabling pointer authentication, this match will fail due to
PAC present in the lr.

Strip PAC from the lr to display the correct symbol name.

Suggested-by: James Morse 
Signed-off-by: Amit Daniel Kachhap 
Reviewed-by: Vincenzo Frascino 
Acked-by: Catalin Marinas 
Signed-off-by: Catalin Marinas