Commit Graph

795 Commits

Author SHA1 Message Date
Linus Torvalds 7d9d077c78 RCU pull request for v5.20 (or whatever)
This pull request contains the following branches:
 
 doc.2022.06.21a: Documentation updates.
 
 fixes.2022.07.19a: Miscellaneous fixes.
 
 nocb.2022.07.19a: Callback-offload updates, perhaps most notably a new
 	RCU_NOCB_CPU_DEFAULT_ALL Kconfig option that causes all CPUs to
 	be offloaded at boot time, regardless of kernel boot parameters.
 	This is useful to battery-powered systems such as ChromeOS
 	and Android.  In addition, a new RCU_NOCB_CPU_CB_BOOST kernel
 	boot parameter prevents offloaded callbacks from interfering
 	with real-time workloads and with energy-efficiency mechanisms.
 
 poll.2022.07.21a: Polled grace-period updates, perhaps most notably
 	making these APIs account for both normal and expedited grace
 	periods.
 
 rcu-tasks.2022.06.21a: Tasks RCU updates, perhaps most notably reducing
 	the CPU overhead of RCU tasks trace grace periods by more than
 	a factor of two on a system with 15,000 tasks.	The reduction
 	is expected to increase with the number of tasks, so it seems
 	reasonable to hypothesize that a system with 150,000 tasks might
 	see a 20-fold reduction in CPU overhead.
 
 torture.2022.06.21a: Torture-test updates.
 
 ctxt.2022.07.05a: Updates that merge RCU's dyntick-idle tracking into
 	context tracking, thus reducing the overhead of transitioning to
 	kernel mode from either idle or nohz_full userspace execution
 	for kernels that track context independently of RCU.  This is
 	expected to be helpful primarily for kernels built with
 	CONFIG_NO_HZ_FULL=y.
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Merge tag 'rcu.2022.07.26a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu

Pull RCU updates from Paul McKenney:

 - Documentation updates

 - Miscellaneous fixes

 - Callback-offload updates, perhaps most notably a new
   RCU_NOCB_CPU_DEFAULT_ALL Kconfig option that causes all CPUs to be
   offloaded at boot time, regardless of kernel boot parameters.

   This is useful to battery-powered systems such as ChromeOS and
   Android. In addition, a new RCU_NOCB_CPU_CB_BOOST kernel boot
   parameter prevents offloaded callbacks from interfering with
   real-time workloads and with energy-efficiency mechanisms

 - Polled grace-period updates, perhaps most notably making these APIs
   account for both normal and expedited grace periods

 - Tasks RCU updates, perhaps most notably reducing the CPU overhead of
   RCU tasks trace grace periods by more than a factor of two on a
   system with 15,000 tasks.

   The reduction is expected to increase with the number of tasks, so it
   seems reasonable to hypothesize that a system with 150,000 tasks
   might see a 20-fold reduction in CPU overhead

 - Torture-test updates

 - Updates that merge RCU's dyntick-idle tracking into context tracking,
   thus reducing the overhead of transitioning to kernel mode from
   either idle or nohz_full userspace execution for kernels that track
   context independently of RCU.

   This is expected to be helpful primarily for kernels built with
   CONFIG_NO_HZ_FULL=y

* tag 'rcu.2022.07.26a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (98 commits)
  rcu: Add irqs-disabled indicator to expedited RCU CPU stall warnings
  rcu: Diagnose extended sync_rcu_do_polled_gp() loops
  rcu: Put panic_on_rcu_stall() after expedited RCU CPU stall warnings
  rcutorture: Test polled expedited grace-period primitives
  rcu: Add polled expedited grace-period primitives
  rcutorture: Verify that polled GP API sees synchronous grace periods
  rcu: Make Tiny RCU grace periods visible to polled APIs
  rcu: Make polled grace-period API account for expedited grace periods
  rcu: Switch polled grace-period APIs to ->gp_seq_polled
  rcu/nocb: Avoid polling when my_rdp->nocb_head_rdp list is empty
  rcu/nocb: Add option to opt rcuo kthreads out of RT priority
  rcu: Add nocb_cb_kthread check to rcu_is_callbacks_kthread()
  rcu/nocb: Add an option to offload all CPUs on boot
  rcu/nocb: Fix NOCB kthreads spawn failure with rcu_nocb_rdp_deoffload() direct call
  rcu/nocb: Invert rcu_state.barrier_mutex VS hotplug lock locking order
  rcu/nocb: Add/del rdp to iterate from rcuog itself
  rcu/tree: Add comment to describe GP-done condition in fqs loop
  rcu: Initialize first_gp_fqs at declaration in rcu_gp_fqs()
  rcu/kvfree: Remove useless monitor_todo flag
  rcu: Cleanup RCU urgency state for offline CPU
  ...
2022-08-02 19:12:45 -07:00
Linus Torvalds 9de1f9c8ca Updates for interrupt core and drivers:
core:
    - Fix a few inconsistencies between UP and SMP vs. interrupt affinities
    - Small updates and cleanups all over the place
 
  drivers:
    - New driver for the LoongArch interrupt controller
    - New driver for the Renesas RZ/G2L interrupt controller
 
    - Hotpath optimization for SiFive PLIC
    - Workaround for broken PLIC edge triggered interrupts
 
    - Simall cleanups and improvements as usual
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Merge tag 'irq-core-2022-08-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull irq updates from Thomas Gleixner:
 "Updates for interrupt core and drivers:

  Core:

   - Fix a few inconsistencies between UP and SMP vs interrupt
     affinities

   - Small updates and cleanups all over the place

  New drivers:

   - LoongArch interrupt controller

   - Renesas RZ/G2L interrupt controller

  Updates:

   - Hotpath optimization for SiFive PLIC

   - Workaround for broken PLIC edge triggered interrupts

   - Simall cleanups and improvements as usual"

* tag 'irq-core-2022-08-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits)
  irqchip/mmp: Declare init functions in common header file
  irqchip/mips-gic: Check the return value of ioremap() in gic_of_init()
  genirq: Use for_each_action_of_desc in actions_show()
  irqchip / ACPI: Introduce ACPI_IRQ_MODEL_LPIC for LoongArch
  irqchip: Add LoongArch CPU interrupt controller support
  irqchip: Add Loongson Extended I/O interrupt controller support
  irqchip/loongson-liointc: Add ACPI init support
  irqchip/loongson-pch-msi: Add ACPI init support
  irqchip/loongson-pch-pic: Add ACPI init support
  irqchip: Add Loongson PCH LPC controller support
  LoongArch: Prepare to support multiple pch-pic and pch-msi irqdomain
  LoongArch: Use ACPI_GENERIC_GSI for gsi handling
  genirq/generic_chip: Export irq_unmap_generic_chip
  ACPI: irq: Allow acpi_gsi_to_irq() to have an arch-specific fallback
  APCI: irq: Add support for multiple GSI domains
  LoongArch: Provisionally add ACPICA data structures
  irqdomain: Use hwirq_max instead of revmap_size for NOMAP domains
  irqdomain: Report irq number for NOMAP domains
  irqchip/gic-v3: Fix comment typo
  dt-bindings: interrupt-controller: renesas,rzg2l-irqc: Document RZ/V2L SoC
  ...
2022-08-01 12:48:15 -07:00
Samuel Holland 4d0b829881 genirq: Return a const cpumask from irq_data_get_affinity_mask
Now that the irq_data_update_affinity helper exists, enforce its use
by returning a a const cpumask from irq_data_get_affinity_mask.

Since the previous commit already updated places that needed to call
irq_data_update_affinity, this commit updates the remaining code that
either did not modify the cpumask or immediately passed the modified
mask to irq_set_affinity.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220701200056.46555-8-samuel@sholland.org
2022-07-07 09:38:04 +01:00
Frederic Weisbecker 24a9c54182 context_tracking: Split user tracking Kconfig
Context tracking is going to be used not only to track user transitions
but also idle/IRQs/NMIs. The user tracking part will then become a
separate feature. Prepare Kconfig for that.

[ frederic: Apply Max Filippov feedback. ]

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Uladzislau Rezki <uladzislau.rezki@sony.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Nicolas Saenz Julienne <nsaenz@kernel.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Cc: Yu Liao <liaoyu15@huawei.com>
Cc: Phil Auld <pauld@redhat.com>
Cc: Paul Gortmaker<paul.gortmaker@windriver.com>
Cc: Alex Belits <abelits@marvell.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
2022-06-29 17:04:09 -07:00
Frederic Weisbecker f163f0302a context_tracking: Rename context_tracking_user_enter/exit() to user_enter/exit_callable()
context_tracking_user_enter() and context_tracking_user_exit() are
ASM callable versions of user_enter() and user_exit() for architectures
that didn't manage to check the context tracking static key from ASM.
Change those function names to better reflect their purpose.

[ frederic: Apply Max Filippov feedback. ]

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Uladzislau Rezki <uladzislau.rezki@sony.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Nicolas Saenz Julienne <nsaenz@kernel.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Cc: Yu Liao <liaoyu15@huawei.com>
Cc: Phil Auld <pauld@redhat.com>
Cc: Paul Gortmaker<paul.gortmaker@windriver.com>
Cc: Alex Belits <abelits@marvell.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
2022-06-29 17:03:27 -07:00
Max Filippov a2d9b75b19 xtensa: change '.bss' to '.section .bss'
For some reason (ancient assembler?) the following build error is
reported by the kisskb:

  kisskb/src/arch/xtensa/kernel/entry.S: Error: unknown pseudo-op: `.bss':
  => 2176

Change abbreviated '.bss' to the full '.section .bss, "aw"' to fix this
error.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2022-06-20 02:50:34 -07:00
Liang He a0117dc956 xtensa: Fix refcount leak bug in time.c
In calibrate_ccount(), of_find_compatible_node() will return a node
pointer with refcount incremented. We should use of_node_put() when
it is not used anymore.

Cc: stable@vger.kernel.org
Signed-off-by: Liang He <windhl@126.com>
Message-Id: <20220617124432.4049006-1-windhl@126.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2022-06-18 14:46:59 -07:00
Linus Torvalds 67850b7bdc While looking at the ptrace problems with PREEMPT_RT and the problems
of Peter Zijlstra was encountering with ptrace in his freezer rewrite
 I identified some cleanups to ptrace_stop that make sense on their own
 and move make resolving the other problems much simpler.
 
 The biggest issue is the habbit of the ptrace code to change task->__state
 from the tracer to suppress TASK_WAKEKILL from waking up the tracee.  No
 other code in the kernel does that and it is straight forward to update
 signal_wake_up and friends to make that unnecessary.
 
 Peter's task freezer sets frozen tasks to a new state TASK_FROZEN and
 then it stores them by calling "wake_up_state(t, TASK_FROZEN)" relying
 on the fact that all stopped states except the special stop states can
 tolerate spurious wake up and recover their state.
 
 The state of stopped and traced tasked is changed to be stored in
 task->jobctl as well as in task->__state.  This makes it possible for
 the freezer to recover tasks in these special states, as well as
 serving as a general cleanup.  With a little more work in that
 direction I believe TASK_STOPPED can learn to tolerate spurious wake
 ups and become an ordinary stop state.
 
 The TASK_TRACED state has to remain a special state as the registers for
 a process are only reliably available when the process is stopped in
 the scheduler.  Fundamentally ptrace needs acess to the saved
 register values of a task.
 
 There are bunch of semi-random ptrace related cleanups that were found
 while looking at these issues.
 
 One cleanup that deserves to be called out is from commit 57b6de08b5
 ("ptrace: Admit ptrace_stop can generate spuriuos SIGTRAPs").  This
 makes a change that is technically user space visible, in the handling
 of what happens to a tracee when a tracer dies unexpectedly.
 According to our testing and our understanding of userspace nothing
 cares that spurious SIGTRAPs can be generated in that case.
 
 The entire discussion can be found at:
   https://lkml.kernel.org/r/87a6bv6dl6.fsf_-_@email.froward.int.ebiederm.org
 
 Eric W. Biederman (11):
       signal: Rename send_signal send_signal_locked
       signal: Replace __group_send_sig_info with send_signal_locked
       ptrace/um: Replace PT_DTRACE with TIF_SINGLESTEP
       ptrace/xtensa: Replace PT_SINGLESTEP with TIF_SINGLESTEP
       ptrace: Remove arch_ptrace_attach
       signal: Use lockdep_assert_held instead of assert_spin_locked
       ptrace: Reimplement PTRACE_KILL by always sending SIGKILL
       ptrace: Document that wait_task_inactive can't fail
       ptrace: Admit ptrace_stop can generate spuriuos SIGTRAPs
       ptrace: Don't change __state
       ptrace: Always take siglock in ptrace_resume
 
 Peter Zijlstra (1):
       sched,signal,ptrace: Rework TASK_TRACED, TASK_STOPPED state
 
  arch/ia64/include/asm/ptrace.h    |   4 --
  arch/ia64/kernel/ptrace.c         |  57 ----------------
  arch/um/include/asm/thread_info.h |   2 +
  arch/um/kernel/exec.c             |   2 +-
  arch/um/kernel/process.c          |   2 +-
  arch/um/kernel/ptrace.c           |   8 +--
  arch/um/kernel/signal.c           |   4 +-
  arch/x86/kernel/step.c            |   3 +-
  arch/xtensa/kernel/ptrace.c       |   4 +-
  arch/xtensa/kernel/signal.c       |   4 +-
  drivers/tty/tty_jobctrl.c         |   4 +-
  include/linux/ptrace.h            |   7 --
  include/linux/sched.h             |  10 ++-
  include/linux/sched/jobctl.h      |   8 +++
  include/linux/sched/signal.h      |  20 ++++--
  include/linux/signal.h            |   3 +-
  kernel/ptrace.c                   |  87 ++++++++---------------
  kernel/sched/core.c               |   5 +-
  kernel/signal.c                   | 140 +++++++++++++++++---------------------
  kernel/time/posix-cpu-timers.c    |   6 +-
  20 files changed, 140 insertions(+), 240 deletions(-)
 
 Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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Merge tag 'ptrace_stop-cleanup-for-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

Pull ptrace_stop cleanups from Eric Biederman:
 "While looking at the ptrace problems with PREEMPT_RT and the problems
  Peter Zijlstra was encountering with ptrace in his freezer rewrite I
  identified some cleanups to ptrace_stop that make sense on their own
  and move make resolving the other problems much simpler.

  The biggest issue is the habit of the ptrace code to change
  task->__state from the tracer to suppress TASK_WAKEKILL from waking up
  the tracee. No other code in the kernel does that and it is straight
  forward to update signal_wake_up and friends to make that unnecessary.

  Peter's task freezer sets frozen tasks to a new state TASK_FROZEN and
  then it stores them by calling "wake_up_state(t, TASK_FROZEN)" relying
  on the fact that all stopped states except the special stop states can
  tolerate spurious wake up and recover their state.

  The state of stopped and traced tasked is changed to be stored in
  task->jobctl as well as in task->__state. This makes it possible for
  the freezer to recover tasks in these special states, as well as
  serving as a general cleanup. With a little more work in that
  direction I believe TASK_STOPPED can learn to tolerate spurious wake
  ups and become an ordinary stop state.

  The TASK_TRACED state has to remain a special state as the registers
  for a process are only reliably available when the process is stopped
  in the scheduler. Fundamentally ptrace needs acess to the saved
  register values of a task.

  There are bunch of semi-random ptrace related cleanups that were found
  while looking at these issues.

  One cleanup that deserves to be called out is from commit 57b6de08b5
  ("ptrace: Admit ptrace_stop can generate spuriuos SIGTRAPs"). This
  makes a change that is technically user space visible, in the handling
  of what happens to a tracee when a tracer dies unexpectedly. According
  to our testing and our understanding of userspace nothing cares that
  spurious SIGTRAPs can be generated in that case"

* tag 'ptrace_stop-cleanup-for-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  sched,signal,ptrace: Rework TASK_TRACED, TASK_STOPPED state
  ptrace: Always take siglock in ptrace_resume
  ptrace: Don't change __state
  ptrace: Admit ptrace_stop can generate spuriuos SIGTRAPs
  ptrace: Document that wait_task_inactive can't fail
  ptrace: Reimplement PTRACE_KILL by always sending SIGKILL
  signal: Use lockdep_assert_held instead of assert_spin_locked
  ptrace: Remove arch_ptrace_attach
  ptrace/xtensa: Replace PT_SINGLESTEP with TIF_SINGLESTEP
  ptrace/um: Replace PT_DTRACE with TIF_SINGLESTEP
  signal: Replace __group_send_sig_info with send_signal_locked
  signal: Rename send_signal send_signal_locked
2022-06-03 16:13:25 -07:00
Linus Torvalds 1ec6574a3c This set of changes updates init and user mode helper tasks to be
ordinary user mode tasks.
 
 In commit 40966e316f ("kthread: Ensure struct kthread is present for
 all kthreads") caused init and the user mode helper threads that call
 kernel_execve to have struct kthread allocated for them.  This struct
 kthread going away during execve in turned made a use after free of
 struct kthread possible.
 
 The commit 343f4c49f2 ("kthread: Don't allocate kthread_struct for
 init and umh") is enough to fix the use after free and is simple enough
 to be backportable.
 
 The rest of the changes pass struct kernel_clone_args to clean things
 up and cause the code to make sense.
 
 In making init and the user mode helpers tasks purely user mode tasks
 I ran into two complications.  The function task_tick_numa was
 detecting tasks without an mm by testing for the presence of
 PF_KTHREAD.  The initramfs code in populate_initrd_image was using
 flush_delayed_fput to ensuere the closing of all it's file descriptors
 was complete, and flush_delayed_fput does not work in a userspace thread.
 
 I have looked and looked and more complications and in my code review
 I have not found any, and neither has anyone else with the code sitting
 in linux-next.
 
 Link: https://lkml.kernel.org/r/87mtfu4up3.fsf@email.froward.int.ebiederm.org
 
 Eric W. Biederman (8):
       kthread: Don't allocate kthread_struct for init and umh
       fork: Pass struct kernel_clone_args into copy_thread
       fork: Explicity test for idle tasks in copy_thread
       fork: Generalize PF_IO_WORKER handling
       init: Deal with the init process being a user mode process
       fork: Explicitly set PF_KTHREAD
       fork: Stop allowing kthreads to call execve
       sched: Update task_tick_numa to ignore tasks without an mm
 
  arch/alpha/kernel/process.c      | 13 ++++++------
  arch/arc/kernel/process.c        | 13 ++++++------
  arch/arm/kernel/process.c        | 12 ++++++-----
  arch/arm64/kernel/process.c      | 12 ++++++-----
  arch/csky/kernel/process.c       | 15 ++++++-------
  arch/h8300/kernel/process.c      | 10 ++++-----
  arch/hexagon/kernel/process.c    | 12 ++++++-----
  arch/ia64/kernel/process.c       | 15 +++++++------
  arch/m68k/kernel/process.c       | 12 ++++++-----
  arch/microblaze/kernel/process.c | 12 ++++++-----
  arch/mips/kernel/process.c       | 13 ++++++------
  arch/nios2/kernel/process.c      | 12 ++++++-----
  arch/openrisc/kernel/process.c   | 12 ++++++-----
  arch/parisc/kernel/process.c     | 18 +++++++++-------
  arch/powerpc/kernel/process.c    | 15 +++++++------
  arch/riscv/kernel/process.c      | 12 ++++++-----
  arch/s390/kernel/process.c       | 12 ++++++-----
  arch/sh/kernel/process_32.c      | 12 ++++++-----
  arch/sparc/kernel/process_32.c   | 12 ++++++-----
  arch/sparc/kernel/process_64.c   | 12 ++++++-----
  arch/um/kernel/process.c         | 15 +++++++------
  arch/x86/include/asm/fpu/sched.h |  2 +-
  arch/x86/include/asm/switch_to.h |  8 +++----
  arch/x86/kernel/fpu/core.c       |  4 ++--
  arch/x86/kernel/process.c        | 18 +++++++++-------
  arch/xtensa/kernel/process.c     | 17 ++++++++-------
  fs/exec.c                        |  8 ++++---
  include/linux/sched/task.h       |  8 +++++--
  init/initramfs.c                 |  2 ++
  init/main.c                      |  2 +-
  kernel/fork.c                    | 46 +++++++++++++++++++++++++++++++++-------
  kernel/sched/fair.c              |  2 +-
  kernel/umh.c                     |  6 +++---
  33 files changed, 234 insertions(+), 160 deletions(-)
 
 Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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Merge tag 'kthread-cleanups-for-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

Pull kthread updates from Eric Biederman:
 "This updates init and user mode helper tasks to be ordinary user mode
  tasks.

  Commit 40966e316f ("kthread: Ensure struct kthread is present for
  all kthreads") caused init and the user mode helper threads that call
  kernel_execve to have struct kthread allocated for them. This struct
  kthread going away during execve in turned made a use after free of
  struct kthread possible.

  Here, commit 343f4c49f2 ("kthread: Don't allocate kthread_struct for
  init and umh") is enough to fix the use after free and is simple
  enough to be backportable.

  The rest of the changes pass struct kernel_clone_args to clean things
  up and cause the code to make sense.

  In making init and the user mode helpers tasks purely user mode tasks
  I ran into two complications. The function task_tick_numa was
  detecting tasks without an mm by testing for the presence of
  PF_KTHREAD. The initramfs code in populate_initrd_image was using
  flush_delayed_fput to ensuere the closing of all it's file descriptors
  was complete, and flush_delayed_fput does not work in a userspace
  thread.

  I have looked and looked and more complications and in my code review
  I have not found any, and neither has anyone else with the code
  sitting in linux-next"

* tag 'kthread-cleanups-for-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  sched: Update task_tick_numa to ignore tasks without an mm
  fork: Stop allowing kthreads to call execve
  fork: Explicitly set PF_KTHREAD
  init: Deal with the init process being a user mode process
  fork: Generalize PF_IO_WORKER handling
  fork: Explicity test for idle tasks in copy_thread
  fork: Pass struct kernel_clone_args into copy_thread
  kthread: Don't allocate kthread_struct for init and umh
2022-06-03 16:03:05 -07:00
Yang Li dc60001e1a xtensa: Return true/false (not 1/0) from bool function
Return boolean values ("true" or "false") instead of 1 or 0 from bool
function. This fixes the following warnings from coccicheck:

./arch/xtensa/kernel/traps.c:304:10-11: WARNING: return of 0/1 in
function 'check_div0' with return type bool

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Message-Id: <20220518230953.112266-1-yang.lee@linux.alibaba.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2022-05-23 00:33:05 -07:00
Max Filippov 5cc5f19f88 xtensa: improve call0 ABI probing
When call0 userspace ABI support by probing is enabled instructions that
cause illegal instruction exception when PS.WOE is clear are retried
with PS.WOE set before calling c-level exception handler. Record user pc
at which PS.WOE was set in the fast exception handler and clear PS.WOE
in the c-level exception handler if we get there from the same address.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2022-05-17 03:35:43 -07:00
Max Filippov d74862007e xtensa: support artificial division by 0 exception
On xtensa cores wihout hardware division option division support
functions from libgcc react to division by 0 attempt by executing
illegal instruction followed by the characters 'DIV0'. Recognize this
pattern in illegal instruction exception handler and convert it to
division by 0.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2022-05-17 03:35:43 -07:00
Max Filippov 408b1d3c0e xtensa: add trap handler for division by zero
Add c-level handler for the division by zero exception and kill the task
if it was thrown from the kernel space or send SIGFPE otherwise.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2022-05-13 08:43:36 -07:00
Eric W. Biederman 4a3d2717d1 ptrace/xtensa: Replace PT_SINGLESTEP with TIF_SINGLESTEP
xtensa is the last user of the PT_SINGLESTEP flag.  Changing tsk->ptrace in
user_enable_single_step and user_disable_single_step without locking could
potentiallly cause problems.

So use a thread info flag instead of a flag in tsk->ptrace.  Use TIF_SINGLESTEP
that xtensa already had defined but unused.

Remove the definitions of PT_SINGLESTEP and PT_BLOCKSTEP as they have no more users.

Cc: stable@vger.kernel.org
Acked-by: Max Filippov <jcmvbkbc@gmail.com>
Tested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lkml.kernel.org/r/20220505182645.497868-4-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-05-11 14:33:44 -05:00
Eric W. Biederman 5bd2e97c86 fork: Generalize PF_IO_WORKER handling
Add fn and fn_arg members into struct kernel_clone_args and test for
them in copy_thread (instead of testing for PF_KTHREAD | PF_IO_WORKER).
This allows any task that wants to be a user space task that only runs
in kernel mode to use this functionality.

The code on x86 is an exception and still retains a PF_KTHREAD test
because x86 unlikely everything else handles kthreads slightly
differently than user space tasks that start with a function.

The functions that created tasks that start with a function
have been updated to set ".fn" and ".fn_arg" instead of
".stack" and ".stack_size".  These functions are fork_idle(),
create_io_thread(), kernel_thread(), and user_mode_thread().

Link: https://lkml.kernel.org/r/20220506141512.516114-4-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-05-07 09:01:59 -05:00
Eric W. Biederman c5febea095 fork: Pass struct kernel_clone_args into copy_thread
With io_uring we have started supporting tasks that are for most
purposes user space tasks that exclusively run code in kernel mode.

The kernel task that exec's init and tasks that exec user mode
helpers are also user mode tasks that just run kernel code
until they call kernel execve.

Pass kernel_clone_args into copy_thread so these oddball
tasks can be supported more cleanly and easily.

v2: Fix spelling of kenrel_clone_args on h8300
Link: https://lkml.kernel.org/r/20220506141512.516114-2-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-05-07 09:01:48 -05:00
Max Filippov 7f9c974174 xtensa: clean up labels in the kernel entry assembly
Don't use numeric labels for long jumps, use named local labels instead.
Avoid conditional label definition.
No functional changes.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2022-05-01 19:58:33 -07:00
Max Filippov 2a26f4ee39 xtensa: don't leave invalid TLB entry in fast_store_prohibited
When fast_store_prohibited needs to go to the C-level exception handler
it leaves TLB entry that caused page fault in the TLB. If the faulting
task gets switched to a different CPU and completes page table update
there the TLB entry will get out of sync with the page table which may
cause a livelock on access to that page.
Invalidate faulting TLB entry on a slow path exit from the
fast_store_prohibited.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2022-05-01 19:58:12 -07:00
Max Filippov 733f5c28e5 xtensa: add hibernation support
Define ARCH_HIBERNATION_POSSIBLE in Kconfig and implement hibernation
callbacks.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2022-05-01 19:51:24 -07:00
Max Filippov 11e969bc96 xtensa: support coprocessors on SMP
Current coprocessor support on xtensa only works correctly on
uniprocessor configurations. Make it work on SMP too and keep it lazy.

Make coprocessor_owner array per-CPU and move it to struct exc_table for
easy access from the fast_coprocessor exception handler. Allow task to
have live coprocessors only on single CPU, record this CPU number in the
struct thread_info::cp_owner_cpu. Change struct thread_info::cpenable
meaning to be 'coprocessors live on cp_owner_cpu'.
Introduce C-level coprocessor exception handler that flushes and
releases live coprocessors of the task taking 'coprocessor disabled'
exception and call it from the fast_coprocessor handler when the task
has live coprocessors on other CPU.
Make coprocessor_flush_all and coprocessor_release_all work correctly
when called from any CPU by sending IPI to the cp_owner_cpu. Add
function coprocessor_flush_release_all to do flush followed by release
atomically. Add function local_coprocessors_flush_release_all to flush
and release all coprocessors on the local CPU and use it to flush
coprocessor contexts from the CPU that goes offline.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2022-05-01 19:51:23 -07:00
Max Filippov f29cab2906 xtensa: get rid of stack frame in coprocessor_flush
coprocessor_flush is an ordinary function, it can use all registers.
Don't reserve stack frame for it and use a7 to preserve a0 around the
context saving call.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2022-05-01 19:51:23 -07:00
Max Filippov e45d4bfbeb xtensa: merge SAVE_CP_REGS_TAB and LOAD_CP_REGS_TAB
Both tables share the same offset field but the different function
pointers. Merge them into single table with 3-element entries to reduce
code and data duplication.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2022-05-01 19:51:23 -07:00
Max Filippov 0b549f8133 xtensa: handle coprocessor exceptions in kernel mode
In order to let drivers use xtensa coprocessors on behalf of the calling
process the kernel must handle coprocessor exceptions from the kernel
mode the same way as from the user mode.

This is not sufficient to allow using coprocessors transparently in IRQ
or softirq context. Should such users exist they must be aware of the
context and do the right thing, e.g. preserve the coprocessor state and
resore it after use.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2022-05-01 19:51:23 -07:00
Max Filippov 6179ef4d46 xtensa: use callx0 opcode in fast_coprocessor
Instead of emulating call0 in fast_coprocessor use that opcode directly.
Use 'ret' instead of 'jx a0'.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2022-05-01 19:51:23 -07:00
Max Filippov 9fa8c59f5f xtensa: clean up excsave1 initialization
Use xtensa_set_sr instead of inline assembly.
Rename local variable exc_table in early_trap_init to avoid conflict
with per-CPU variable of the same name.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2022-05-01 19:51:22 -07:00
Max Filippov fc55402b84 xtensa: clean up exception handler prototypes
Exception handlers are currently passed as void pointers because they
may have one or two parameters. Only two handlers uses the second
parameter and it is available in the struct pt_regs anyway. Make all
handlers have only one parameter, introduce xtensa_exception_handler
type for handlers and use it in trap_set_handler.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2022-05-01 19:51:22 -07:00
Max Filippov db0d07fa19 xtensa: clean up function declarations in traps.c
Drop 'extern' from all function declarations and move those that need to
be visible from traps.c to traps.h. Add 'asmlinkage' to declarations of
fucntions defined in assembly. Add 'static' to declarations and
definitions only used locally. Add argument names in declarations.
Drop unused second argument from do_multihit and do_page_fault.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2022-05-01 19:51:22 -07:00
Max Filippov 55427d5b0d xtensa: enable context tracking
Put user exit context tracking call on the common kernel entry/exit path
(function calls are impossible at earlier kernel entry stages because
PS.EXCM is not cleared yet). Put user entry context tracking call on the
user exit path. Syscalls go through this common code too, so nothing
specific needs to be done for them.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2022-05-01 19:51:21 -07:00
Max Filippov 961c5efbc4 xtensa: use abi_* register names in the kernel exit code
Using plain register names is prone to errors when code is changed and
new calls are added between the register load and use. Change plain
register names to abi_* names in the call-heavy part of the kernel exit
code to clearly indicate what's supposed to be preserved and what's not.
Re-align code while at it.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2022-05-01 19:51:21 -07:00
Max Filippov de4415d0ba xtensa: move trace_hardirqs_off call back to entry.S
Context tracking call must be done after hardirq tracking call,
otherwise lockdep_assert_irqs_disabled called from rcu_eqs_exit gives
a warning. To avoid context tracking logic duplication for IRQ/exception
entry paths move trace_hardirqs_off call back to common entry code.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2022-05-01 19:51:21 -07:00
Max Filippov 4b81690980 xtensa: drop dead code from entry.S
KERNEL_STACK_OVERFLOW_CHECK is incomplete and have never been enabled.
Remove it.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2022-05-01 19:51:21 -07:00
Max Filippov a8f0c31fa8 xtensa: noMMU: allow handling protection faults
Many xtensa CPU cores without full MMU still have memory protection
features capable of raising exceptions for invalid instruction
fetches/data access. Allow handling such exceptions. This improves
behavior of processes that pass invalid memory pointers to syscalls in
noMMU configs: in case of exception the kernel instead of killing the
process is now able to return -EINVAL from a syscall.

Introduce CONFIG_PFAULT that controls whether protection fault code is
enabled and register handlers for common memory protection exceptions
when it is enabled.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2022-05-01 19:51:21 -07:00
Max Filippov 839769c354 xtensa: fix a7 clobbering in coprocessor context load/store
Fast coprocessor exception handler saves a3..a6, but coprocessor context
load/store code uses a4..a7 as temporaries, potentially clobbering a7.
'Potentially' because coprocessor state load/store macros may not use
all four temporary registers (and neither FPU nor HiFi macros do).
Use a3..a6 as intended.

Cc: stable@vger.kernel.org
Fixes: c658eac628 ("[XTENSA] Add support for configurable registers and coprocessors")
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2022-04-15 18:44:02 -07:00
Guo Ren ee69d4be8f xtensa: patch_text: Fixup last cpu should be master
These patch_text implementations are using stop_machine_cpuslocked
infrastructure with atomic cpu_count. The original idea: When the
master CPU patch_text, the others should wait for it. But current
implementation is using the first CPU as master, which couldn't
guarantee the remaining CPUs are waiting. This patch changes the
last CPU as the master to solve the potential risk.

Fixes: 64711f9a47 ("xtensa: implement jump_label support")
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Max Filippov <jcmvbkbc@gmail.com>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: <stable@vger.kernel.org>
Message-Id: <20220407073323.743224-4-guoren@kernel.org>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2022-04-13 03:36:34 -07:00
Linus Torvalds b8321ed4a4 Kbuild updates for v5.18
- Add new environment variables, USERCFLAGS and USERLDFLAGS to allow
    additional flags to be passed to user-space programs.
 
  - Fix missing fflush() bugs in Kconfig and fixdep
 
  - Fix a minor bug in the comment format of the .config file
 
  - Make kallsyms ignore llvm's local labels, .L*
 
  - Fix UAPI compile-test for cross-compiling with Clang
 
  - Extend the LLVM= syntax to support LLVM=<suffix> form for using a
    particular version of LLVm, and LLVM=<prefix> form for using custom
    LLVM in a particular directory path.
 
  - Clean up Makefiles
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Merge tag 'kbuild-v5.18-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Add new environment variables, USERCFLAGS and USERLDFLAGS to allow
   additional flags to be passed to user-space programs.

 - Fix missing fflush() bugs in Kconfig and fixdep

 - Fix a minor bug in the comment format of the .config file

 - Make kallsyms ignore llvm's local labels, .L*

 - Fix UAPI compile-test for cross-compiling with Clang

 - Extend the LLVM= syntax to support LLVM=<suffix> form for using a
   particular version of LLVm, and LLVM=<prefix> form for using custom
   LLVM in a particular directory path.

 - Clean up Makefiles

* tag 'kbuild-v5.18-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: Make $(LLVM) more flexible
  kbuild: add --target to correctly cross-compile UAPI headers with Clang
  fixdep: use fflush() and ferror() to ensure successful write to files
  arch: syscalls: simplify uapi/kapi directory creation
  usr/include: replace extra-y with always-y
  certs: simplify empty certs creation in certs/Makefile
  certs: include certs/signing_key.x509 unconditionally
  kallsyms: ignore all local labels prefixed by '.L'
  kconfig: fix missing '# end of' for empty menu
  kconfig: add fflush() before ferror() check
  kbuild: replace $(if A,A,B) with $(or A,B)
  kbuild: Add environment variables for userprogs flags
  kbuild: unify cmd_copy and cmd_shipped
2022-03-31 11:59:03 -07:00
Masahiro Yamada bbc90bc1bd arch: syscalls: simplify uapi/kapi directory creation
$(shell ...) expands to empty. There is no need to assign it to _dummy.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
2022-03-31 12:03:46 +09:00
Linus Torvalds 1930a6e739 ptrace: Cleanups for v5.18
This set of changes removes tracehook.h, moves modification of all of
 the ptrace fields inside of siglock to remove races, adds a missing
 permission check to ptrace.c
 
 The removal of tracehook.h is quite significant as it has been a major
 source of confusion in recent years.  Much of that confusion was
 around task_work and TIF_NOTIFY_SIGNAL (which I have now decoupled
 making the semantics clearer).
 
 For people who don't know tracehook.h is a vestiage of an attempt to
 implement uprobes like functionality that was never fully merged, and
 was later superseeded by uprobes when uprobes was merged.  For many
 years now we have been removing what tracehook functionaly a little
 bit at a time.  To the point where now anything left in tracehook.h is
 some weird strange thing that is difficult to understand.
 
 Eric W. Biederman (15):
       ptrace: Move ptrace_report_syscall into ptrace.h
       ptrace/arm: Rename tracehook_report_syscall report_syscall
       ptrace: Create ptrace_report_syscall_{entry,exit} in ptrace.h
       ptrace: Remove arch_syscall_{enter,exit}_tracehook
       ptrace: Remove tracehook_signal_handler
       task_work: Remove unnecessary include from posix_timers.h
       task_work: Introduce task_work_pending
       task_work: Call tracehook_notify_signal from get_signal on all architectures
       task_work: Decouple TIF_NOTIFY_SIGNAL and task_work
       signal: Move set_notify_signal and clear_notify_signal into sched/signal.h
       resume_user_mode: Remove #ifdef TIF_NOTIFY_RESUME in set_notify_resume
       resume_user_mode: Move to resume_user_mode.h
       tracehook: Remove tracehook.h
       ptrace: Move setting/clearing ptrace_message into ptrace_stop
       ptrace: Return the signal to continue with from ptrace_stop
 
 Jann Horn (1):
       ptrace: Check PTRACE_O_SUSPEND_SECCOMP permission on PTRACE_SEIZE
 
 Yang Li (1):
       ptrace: Remove duplicated include in ptrace.c
 
  MAINTAINERS                          |   1 -
  arch/Kconfig                         |   5 +-
  arch/alpha/kernel/ptrace.c           |   5 +-
  arch/alpha/kernel/signal.c           |   4 +-
  arch/arc/kernel/ptrace.c             |   5 +-
  arch/arc/kernel/signal.c             |   4 +-
  arch/arm/kernel/ptrace.c             |  12 +-
  arch/arm/kernel/signal.c             |   4 +-
  arch/arm64/kernel/ptrace.c           |  14 +--
  arch/arm64/kernel/signal.c           |   4 +-
  arch/csky/kernel/ptrace.c            |   5 +-
  arch/csky/kernel/signal.c            |   4 +-
  arch/h8300/kernel/ptrace.c           |   5 +-
  arch/h8300/kernel/signal.c           |   4 +-
  arch/hexagon/kernel/process.c        |   4 +-
  arch/hexagon/kernel/signal.c         |   1 -
  arch/hexagon/kernel/traps.c          |   6 +-
  arch/ia64/kernel/process.c           |   4 +-
  arch/ia64/kernel/ptrace.c            |   6 +-
  arch/ia64/kernel/signal.c            |   1 -
  arch/m68k/kernel/ptrace.c            |   5 +-
  arch/m68k/kernel/signal.c            |   4 +-
  arch/microblaze/kernel/ptrace.c      |   5 +-
  arch/microblaze/kernel/signal.c      |   4 +-
  arch/mips/kernel/ptrace.c            |   5 +-
  arch/mips/kernel/signal.c            |   4 +-
  arch/nds32/include/asm/syscall.h     |   2 +-
  arch/nds32/kernel/ptrace.c           |   5 +-
  arch/nds32/kernel/signal.c           |   4 +-
  arch/nios2/kernel/ptrace.c           |   5 +-
  arch/nios2/kernel/signal.c           |   4 +-
  arch/openrisc/kernel/ptrace.c        |   5 +-
  arch/openrisc/kernel/signal.c        |   4 +-
  arch/parisc/kernel/ptrace.c          |   7 +-
  arch/parisc/kernel/signal.c          |   4 +-
  arch/powerpc/kernel/ptrace/ptrace.c  |   8 +-
  arch/powerpc/kernel/signal.c         |   4 +-
  arch/riscv/kernel/ptrace.c           |   5 +-
  arch/riscv/kernel/signal.c           |   4 +-
  arch/s390/include/asm/entry-common.h |   1 -
  arch/s390/kernel/ptrace.c            |   1 -
  arch/s390/kernel/signal.c            |   5 +-
  arch/sh/kernel/ptrace_32.c           |   5 +-
  arch/sh/kernel/signal_32.c           |   4 +-
  arch/sparc/kernel/ptrace_32.c        |   5 +-
  arch/sparc/kernel/ptrace_64.c        |   5 +-
  arch/sparc/kernel/signal32.c         |   1 -
  arch/sparc/kernel/signal_32.c        |   4 +-
  arch/sparc/kernel/signal_64.c        |   4 +-
  arch/um/kernel/process.c             |   4 +-
  arch/um/kernel/ptrace.c              |   5 +-
  arch/x86/kernel/ptrace.c             |   1 -
  arch/x86/kernel/signal.c             |   5 +-
  arch/x86/mm/tlb.c                    |   1 +
  arch/xtensa/kernel/ptrace.c          |   5 +-
  arch/xtensa/kernel/signal.c          |   4 +-
  block/blk-cgroup.c                   |   2 +-
  fs/coredump.c                        |   1 -
  fs/exec.c                            |   1 -
  fs/io-wq.c                           |   6 +-
  fs/io_uring.c                        |  11 +-
  fs/proc/array.c                      |   1 -
  fs/proc/base.c                       |   1 -
  include/asm-generic/syscall.h        |   2 +-
  include/linux/entry-common.h         |  47 +-------
  include/linux/entry-kvm.h            |   2 +-
  include/linux/posix-timers.h         |   1 -
  include/linux/ptrace.h               |  81 ++++++++++++-
  include/linux/resume_user_mode.h     |  64 ++++++++++
  include/linux/sched/signal.h         |  17 +++
  include/linux/task_work.h            |   5 +
  include/linux/tracehook.h            | 226 -----------------------------------
  include/uapi/linux/ptrace.h          |   2 +-
  kernel/entry/common.c                |  19 +--
  kernel/entry/kvm.c                   |   9 +-
  kernel/exit.c                        |   3 +-
  kernel/livepatch/transition.c        |   1 -
  kernel/ptrace.c                      |  47 +++++---
  kernel/seccomp.c                     |   1 -
  kernel/signal.c                      |  62 +++++-----
  kernel/task_work.c                   |   4 +-
  kernel/time/posix-cpu-timers.c       |   1 +
  mm/memcontrol.c                      |   2 +-
  security/apparmor/domain.c           |   1 -
  security/selinux/hooks.c             |   1 -
  85 files changed, 372 insertions(+), 495 deletions(-)
 
 Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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Merge tag 'ptrace-cleanups-for-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

Pull ptrace cleanups from Eric Biederman:
 "This set of changes removes tracehook.h, moves modification of all of
  the ptrace fields inside of siglock to remove races, adds a missing
  permission check to ptrace.c

  The removal of tracehook.h is quite significant as it has been a major
  source of confusion in recent years. Much of that confusion was around
  task_work and TIF_NOTIFY_SIGNAL (which I have now decoupled making the
  semantics clearer).

  For people who don't know tracehook.h is a vestiage of an attempt to
  implement uprobes like functionality that was never fully merged, and
  was later superseeded by uprobes when uprobes was merged. For many
  years now we have been removing what tracehook functionaly a little
  bit at a time. To the point where anything left in tracehook.h was
  some weird strange thing that was difficult to understand"

* tag 'ptrace-cleanups-for-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  ptrace: Remove duplicated include in ptrace.c
  ptrace: Check PTRACE_O_SUSPEND_SECCOMP permission on PTRACE_SEIZE
  ptrace: Return the signal to continue with from ptrace_stop
  ptrace: Move setting/clearing ptrace_message into ptrace_stop
  tracehook: Remove tracehook.h
  resume_user_mode: Move to resume_user_mode.h
  resume_user_mode: Remove #ifdef TIF_NOTIFY_RESUME in set_notify_resume
  signal: Move set_notify_signal and clear_notify_signal into sched/signal.h
  task_work: Decouple TIF_NOTIFY_SIGNAL and task_work
  task_work: Call tracehook_notify_signal from get_signal on all architectures
  task_work: Introduce task_work_pending
  task_work: Remove unnecessary include from posix_timers.h
  ptrace: Remove tracehook_signal_handler
  ptrace: Remove arch_syscall_{enter,exit}_tracehook
  ptrace: Create ptrace_report_syscall_{entry,exit} in ptrace.h
  ptrace/arm: Rename tracehook_report_syscall report_syscall
  ptrace: Move ptrace_report_syscall into ptrace.h
2022-03-28 17:29:53 -07:00
Linus Torvalds 744465da70 Xtensa updates for v5.18
- remove dependency on the compiler's libgcc
 - allow selection of internal kernel ABI via Kconfig
 - enable compiler plugins support for gcc-12 or newer
 - various minor cleanups and fixes
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Merge tag 'xtensa-20220325' of https://github.com/jcmvbkbc/linux-xtensa

Pull Xtensa updates from Max Filippov:

 - remove dependency on the compiler's libgcc

 - allow selection of internal kernel ABI via Kconfig

 - enable compiler plugins support for gcc-12 or newer

 - various minor cleanups and fixes

* tag 'xtensa-20220325' of https://github.com/jcmvbkbc/linux-xtensa:
  xtensa: define update_mmu_tlb function
  xtensa: fix xtensa_wsr always writing 0
  xtensa: enable plugin support
  xtensa: clean up kernel exit assembly code
  xtensa: rearrange NMI exit path
  xtensa: merge stack alignment definitions
  xtensa: fix DTC warning unit_address_format
  xtensa: fix stop_machine_cpuslocked call in patch_text
  xtensa: make secondary reset vector support conditional
  xtensa: add kernel ABI selection to Kconfig
  xtensa: don't link with libgcc
  xtensa: add helpers for division, remainder and shifts
  xtensa: add missing XCHAL_HAVE_WINDOWED check
  xtensa: use XCHAL_NUM_AREGS as pt_regs::areg size
  xtensa: rename PT_SIZE to PT_KERNEL_SIZE
  xtensa: Remove unused early_read_config_byte() et al declarations
  xtensa: use strscpy to copy strings
  net: xtensa: use strscpy to copy strings
2022-03-25 09:49:39 -07:00
Linus Torvalds 194dfe88d6 asm-generic updates for 5.18
There are three sets of updates for 5.18 in the asm-generic tree:
 
  - The set_fs()/get_fs() infrastructure gets removed for good. This
    was already gone from all major architectures, but now we can
    finally remove it everywhere, which loses some particularly
    tricky and error-prone code.
    There is a small merge conflict against a parisc cleanup, the
    solution is to use their new version.
 
  - The nds32 architecture ends its tenure in the Linux kernel. The
    hardware is still used and the code is in reasonable shape, but
    the mainline port is not actively maintained any more, as all
    remaining users are thought to run vendor kernels that would never
    be updated to a future release.
    There are some obvious conflicts against changes to the removed
    files.
 
  - A series from Masahiro Yamada cleans up some of the uapi header
    files to pass the compile-time checks.
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Merge tag 'asm-generic-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic

Pull asm-generic updates from Arnd Bergmann:
 "There are three sets of updates for 5.18 in the asm-generic tree:

   - The set_fs()/get_fs() infrastructure gets removed for good.

     This was already gone from all major architectures, but now we can
     finally remove it everywhere, which loses some particularly tricky
     and error-prone code. There is a small merge conflict against a
     parisc cleanup, the solution is to use their new version.

   - The nds32 architecture ends its tenure in the Linux kernel.

     The hardware is still used and the code is in reasonable shape, but
     the mainline port is not actively maintained any more, as all
     remaining users are thought to run vendor kernels that would never
     be updated to a future release.

   - A series from Masahiro Yamada cleans up some of the uapi header
     files to pass the compile-time checks"

* tag 'asm-generic-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: (27 commits)
  nds32: Remove the architecture
  uaccess: remove CONFIG_SET_FS
  ia64: remove CONFIG_SET_FS support
  sh: remove CONFIG_SET_FS support
  sparc64: remove CONFIG_SET_FS support
  lib/test_lockup: fix kernel pointer check for separate address spaces
  uaccess: generalize access_ok()
  uaccess: fix type mismatch warnings from access_ok()
  arm64: simplify access_ok()
  m68k: fix access_ok for coldfire
  MIPS: use simpler access_ok()
  MIPS: Handle address errors for accesses above CPU max virtual user address
  uaccess: add generic __{get,put}_kernel_nofault
  nios2: drop access_ok() check from __put_user()
  x86: use more conventional access_ok() definition
  x86: remove __range_not_ok()
  sparc64: add __{get,put}_kernel_nofault()
  nds32: fix access_ok() checks in get/put_user
  uaccess: fix nios2 and microblaze get_user_8()
  sparc64: fix building assembly files
  ...
2022-03-23 18:03:08 -07:00
Max Filippov e7e9614b6b xtensa: clean up kernel exit assembly code
Don't use numeric labels for complex branching logic. Mark each branch
with named local label and use them. Rearrange exit back to kernel mode
to avoid conditional label definition.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2022-03-19 13:08:41 -07:00
Max Filippov e6d423aaae xtensa: rearrange NMI exit path
NMI exit path to userspace should neither check TIF_DB_DISABLED nor call
check_tlb_sanity because NMI shouldn't touch anything related to
userspace. Drop kernel/userspace check in NMI exit path.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2022-03-19 13:08:32 -07:00
Max Filippov f406f2d03e xtensa: fix stop_machine_cpuslocked call in patch_text
patch_text must invoke patch_text_stop_machine on all online CPUs, but
it calls stop_machine_cpuslocked with NULL cpumask. As a result only one
CPU runs patch_text_stop_machine potentially leaving stale icache
entries on other CPUs. Fix that by calling stop_machine_cpuslocked with
cpu_online_mask as the last argument.

Cc: stable@vger.kernel.org
Fixes: 64711f9a47 ("xtensa: implement jump_label support")
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2022-03-16 02:14:20 -07:00
Eric W. Biederman 03248addad resume_user_mode: Move to resume_user_mode.h
Move set_notify_resume and tracehook_notify_resume into resume_user_mode.h.
While doing that rename tracehook_notify_resume to resume_user_mode_work.

Update all of the places that included tracehook.h for these functions to
include resume_user_mode.h instead.

Update all of the callers of tracehook_notify_resume to call
resume_user_mode_work.

Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20220309162454.123006-12-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-03-10 16:51:50 -06:00
Eric W. Biederman 153474ba1a ptrace: Create ptrace_report_syscall_{entry,exit} in ptrace.h
Rename tracehook_report_syscall_{entry,exit} to
ptrace_report_syscall_{entry,exit} and place them in ptrace.h

There is no longer any generic tracehook infractructure so make
these ptrace specific functions ptrace specific.

Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20220309162454.123006-3-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-03-10 13:35:08 -06:00
Max Filippov 89b184f980 xtensa: make secondary reset vector support conditional
Whether xtensa cores start from primary or secondary reset vector is
configurable and may be chosen by board designer or controlled at
runtime. When secondary reset vector is unused its location in memory
may not be writable.
Make secondary reset vector support conditional and don't build and load
secondary reset vector code when it is disabled.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2022-03-09 16:59:18 -08:00
Max Filippov 19c5699f9a xtensa: don't link with libgcc
libgcc may be absent or may have different ABI than the kernel. Don't
link with it. Drop declarations and export for helpers that are not
implemented. Use generic versions of DI mode multiplication and
comparisons. Drop register window spilling helper as it should never be
used by the compiler-generated code.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2022-03-09 14:03:23 -08:00
Max Filippov 8c9ab55c0f xtensa: add missing XCHAL_HAVE_WINDOWED check
Add missing preprocessor conditions to secondary reset vector code.

Fixes: 09af39f649 ("xtensa: use register window specific opcodes only when present")
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2022-03-09 13:59:15 -08:00
Max Filippov 5b835d4cad xtensa: use XCHAL_NUM_AREGS as pt_regs::areg size
struct pt_regs is used to access both kernel and user exception frames.
User exception frames may contain up to XCHAL_NUM_AREG registers that
task creation and signal delivery code may access, but pt_regs::areg
array has only 16 entries that cover only the kernel exception frame.
This results in the following build error:

arch/xtensa/kernel/process.c: In function 'copy_thread':
arch/xtensa/kernel/process.c:262:52: error: array subscript 53 is above
           array bounds of 'long unsigned int[16]' [-Werror=array-bounds]
  262 |                                 put_user(regs->areg[caller_ars+1],

Change struct pt_regs::areg size to XCHAL_NUM_AREGS so that it covers
the whole user exception frame. Adjust task_pt_regs and drop additional
register copying code from copy_thread now that the whole user exception
stack frame is copied.

Reported-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
2022-03-07 12:02:54 -08:00
Max Filippov 6fad9ddc7d xtensa: rename PT_SIZE to PT_KERNEL_SIZE
PT_SIZE is used by the xtensa port to designate kernel exception frame
size. In preparation for struct pt_regs size change rename PT_SIZE to
PT_KERNEL_SIZE for clarity and change its definition to always cover
only the kernel exception frame.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
2022-03-07 12:02:48 -08:00
Jason Wang 9ddef266bc xtensa: use strscpy to copy strings
The strlcpy should not be used because it doesn't limit the source
length. So that it will lead some potential bugs.

But the strscpy doesn't require reading memory from the src string
beyond the specified "count" bytes, and since the return value is
easier to error-check than strlcpy()'s. In addition, the implementation
is robust to the string changing out from underneath it, unlike the
current strlcpy() implementation.

Thus, replace strlcpy with strscpy.

Signed-off-by: Jason Wang <wangborong@cdjrlc.com>
Message-Id: <20211220084756.955307-1-wangborong@cdjrlc.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2022-03-06 20:17:09 -08:00