linux-stable.git/arch/arm64/kernel/process.c, branch linux-4.3.y

arm64: kernel thread don't need to save fpsimd context.

2015-06-11T14:35:23+00:00

kernel thread's default fpsimd state is zero. When fork a thread, if parent is kernel thread,
 and save hardware context to parent's fpsimd state, but this hardware context is user
process's context, because kernel thread don't use fpsimd, it will not introduce issue,
it add a little cost.

Signed-off-by: Janet Liu 
Signed-off-by: Chunyan Zhang 
Signed-off-by: Catalin Marinas

arm64: context-switch user tls register tpidr_el0 for compat tasks

2015-06-01T10:58:36+00:00

Since commit a4780adeefd0 ("ARM: 7735/2: Preserve the user r/w register
TPIDRURW on context switch and fork"), arch/arm/ has context switched
the user-writable TLS register, so do the same for compat tasks running
under the arm64 kernel.

Reported-by: André Hentschel 
Tested-by: André Hentschel 
Signed-off-by: Will Deacon 
Signed-off-by: Catalin Marinas

arm64: kill flush_cache_all()

2015-05-19T14:27:42+00:00

The documented semantics of flush_cache_all are not possible to provide
for arm64 (short of flushing the entire physical address space by VA),
and there are currently no users; KVM uses VA maintenance exclusively,
cpu_reset is never called, and the only two users outside of arch code
cannot be built for arm64.

While cpu_soft_reset and related functions (which call flush_cache_all)
were thought to be useful for kexec, their current implementations only
serve to mask bugs. For correctness kexec will need to perform
maintenance by VA anyway to account for system caches, line migration,
and other subtleties of the cache architecture. As the extent of this
cache maintenance will be kexec-specific, it should probably live in the
kexec code.

This patch removes flush_cache_all, and related unused components,
preventing further abuse.

Signed-off-by: Mark Rutland 
Cc: AKASHI Takahiro 
Cc: Geoff Levand 
Acked-by: Ard Biesheuvel 
Acked-by: Catalin Marinas 
Acked-by: Lorenzo Pieralisi 
Acked-by: Marc Zyngier 
Acked-by: Will Deacon 
Signed-off-by: Catalin Marinas

efi/arm64: use UEFI for system reset and poweroff

2015-03-14T11:00:18+00:00

If UEFI Runtime Services are available, they are preferred over direct
PSCI calls or other methods to reset the system.

For the reset case, we need to hook into machine_restart(), as the
arm_pm_restart function pointer may be overwritten by modules.

Tested-by: Mark Rutland 
Reviewed-by: Mark Rutland 
Reviewed-by: Matt Fleming 
Signed-off-by: Ard Biesheuvel 
Signed-off-by: Catalin Marinas

arm64: ASLR: Don't randomise text when randomise_va_space == 0

2014-10-24T14:47:49+00:00

When user asks to turn off ASLR by writing "0" to
/proc/sys/kernel/randomize_va_space there should not be
any randomization to mmap base, stack, VDSO, libs, text and heap

Currently arm64 violates this behavior by randomising text.
Fix this by defining a constant ELF_ET_DYN_BASE. The randomisation of
mm->mmap_base is done by setup_new_exec -> arch_pick_mmap_layout ->
mmap_base -> mmap_rnd.

Signed-off-by: Arun Chandran 
Signed-off-by: Catalin Marinas

Merge tag 'restart-handler-for-v3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging

2014-10-10T20:38:02+00:00

Pull restart handler infrastructure from Guenter Roeck:
 "This series was supposed to be pulled through various trees using it,
  and I did not plan to send a separate pull request.  As it turns out,
  the pinctrl tree did not merge with it, is now upstream, and uses it,
  meaning there are now build failures.

  Please pull this series directly to fix those build failures"

* tag 'restart-handler-for-v3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  arm/arm64: unexport restart handlers
  watchdog: sunxi: register restart handler with kernel restart handler
  watchdog: alim7101: register restart handler with kernel restart handler
  watchdog: moxart: register restart handler with kernel restart handler
  arm: support restart through restart handler call chain
  arm64: support restart through restart handler call chain
  power/restart: call machine_restart instead of arm_pm_restart
  kernel: add support for kernel restart handler call chain

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

2014-10-08T09:34:24+00:00

Pull arm64 updates from Catalin Marinas:
 - eBPF JIT compiler for arm64
 - CPU suspend backend for PSCI (firmware interface) with standard idle
   states defined in DT (generic idle driver to be merged via a
   different tree)
 - Support for CONFIG_DEBUG_SET_MODULE_RONX
 - Support for unmapped cpu-release-addr (outside kernel linear mapping)
 - set_arch_dma_coherent_ops() implemented and bus notifiers removed
 - EFI_STUB improvements when base of DRAM is occupied
 - Typos in KGDB macros
 - Clean-up to (partially) allow kernel building with LLVM
 - Other clean-ups (extern keyword, phys_addr_t usage)

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (51 commits)
  arm64: Remove unneeded extern keyword
  ARM64: make of_device_ids const
  arm64: Use phys_addr_t type for physical address
  aarch64: filter $x from kallsyms
  arm64: Use DMA_ERROR_CODE to denote failed allocation
  arm64: Fix typos in KGDB macros
  arm64: insn: Add return statements after BUG_ON()
  arm64: debug: don't re-enable debug exceptions on return from el1_dbg
  Revert "arm64: dmi: Add SMBIOS/DMI support"
  arm64: Implement set_arch_dma_coherent_ops() to replace bus notifiers
  of: amba: use of_dma_configure for AMBA devices
  arm64: dmi: Add SMBIOS/DMI support
  arm64: Correct ftrace calls to aarch64_insn_gen_branch_imm()
  arm64:mm: initialize max_mapnr using function set_max_mapnr
  setup: Move unmask of async interrupts after possible earlycon setup
  arm64: LLVMLinux: Fix inline arm64 assembly for use with clang
  arm64: pageattr: Correctly adjust unaligned start addresses
  net: bpf: arm64: fix module memory leak when JIT image build fails
  arm64: add PSCI CPU_SUSPEND based cpu_suspend support
  arm64: kernel: introduce cpu_init_idle CPU operation
  ...

arm/arm64: unexport restart handlers

2014-09-26T07:00:48+00:00

Implementing a restart handler in a module don't make sense as there would
be no guarantee that the module is loaded when a restart is needed.
Unexport arm_pm_restart to ensure that no one gets the idea to do it
anyway.

Signed-off-by: Guenter Roeck 
Acked-by: Catalin Marinas 
Acked-by: Heiko Stuebner 
Cc: Arnd Bergmann 
Cc: David Woodhouse 
Cc: Dmitry Eremin-Solenikov 
Cc: Ingo Molnar 
Cc: Jonas Jensen 
Cc: Maxime Ripard 
Cc: Randy Dunlap 
Cc: Russell King 
Cc: Steven Rostedt 
Cc: Tomasz Figa 
Cc: Will Deacon 
Cc: Wim Van Sebroeck 
Signed-off-by: Andrew Morton

arm64: support restart through restart handler call chain

2014-09-26T07:00:16+00:00

The kernel core now supports a restart handler call chain to restart the
system.  Call it if arm_pm_restart is not set.

Signed-off-by: Guenter Roeck 
Acked-by: Catalin Marinas 
Acked-by: Heiko Stuebner 
Cc: Arnd Bergmann 
Cc: David Woodhouse 
Cc: Dmitry Eremin-Solenikov 
Cc: Ingo Molnar 
Cc: Jonas Jensen 
Cc: Maxime Ripard 
Cc: Randy Dunlap 
Cc: Russell King 
Cc: Steven Rostedt 
Cc: Tomasz Figa 
Cc: Will Deacon 
Cc: Wim Van Sebroeck 
Signed-off-by: Andrew Morton

arm64: flush TLS registers during exec

2014-09-11T17:34:58+00:00

Nathan reports that we leak TLS information from the parent context
during an exec, as we don't clear the TLS registers when flushing the
thread state.

This patch updates the flushing code so that we:

  (1) Unconditionally zero the tpidr_el0 register (since this is fully
      context switched for native tasks and zeroed for compat tasks)

  (2) Zero the tp_value state in thread_info before clearing the
      tpidrr0_el0 register for compat tasks (since this is only writable
      by the set_tls compat syscall and therefore not fully switched).

A missing compiler barrier is also added to the compat set_tls syscall.

Cc: 
Acked-by: Nathan Lynch 
Reported-by: Nathan Lynch 
Signed-off-by: Will Deacon