According to Dave Hansen, WRPKRU is more expensive than RDPKRU. It has
a higher cycle cost and it's also practically a (light) speculation
barrier.

As an optimisation read the current PKRU value and only write the new
one if it is different.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-14-bigeasy@linutronix.de

Dave Hansen asked for __read_pkru() and __write_pkru() to be
symmetrical.

As part of the series __write_pkru() will read back the value and only
write it if it is different.

In order to make both functions symmetrical, move the function
containing only the opcode asm into a function called like the
instruction itself.

__write_pkru() will just invoke wrpkru() but in a follow-up patch will
also read back the value.

 [ bp: Convert asm opcode wrapper names to rd/wrpkru(). ]
Suggested-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Juergen Gross <jgross@suse.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-13-bigeasy@linutronix.de

After changing the argument of __raw_xsave_addr() from a mask to
number Dave suggested to check if it makes sense to do the same for
get_xsave_addr(). As it turns out it does.

Only get_xsave_addr() needs the mask to check if the requested feature
is part of what is supported/saved and then uses the number again. The
shift operation is cheaper compared to fls64() (find last bit set).
Also, the feature number uses less opcode space compared to the mask. :)

Make the get_xsave_addr() argument a xfeature number instead of a mask
and fix up its callers.

Furthermore, use xfeature_nr and xfeature_mask consistently.

This results in the following changes to the kvm code:

  feature -> xfeature_mask
  index -> xfeature_nr
Suggested-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Rik van Riel <riel@surriel.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Siarhei Liakh <Siarhei.Liakh@concurrent-rt.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-12-bigeasy@linutronix.de

Most users of __raw_xsave_addr() use a feature number, shift it to a
mask and then __raw_xsave_addr() shifts it back to the feature number.

Make __raw_xsave_addr() use the feature number as an argument.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-11-bigeasy@linutronix.de

Add a helper function that ensures the floating point registers for the
current task are active. Use with preemption disabled.

While at it, add fpregs_lock/unlock() helpers too, to be used in later
patches.

 [ bp: Add a comment about its intended usage. ]
Signed-off-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aubrey Li <aubrey.li@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-10-bigeasy@linutronix.de

user_fpu_begin() sets fpu_fpregs_owner_ctx to task's fpu struct. This is
always the case since there is no lazy FPU anymore.

fpu_fpregs_owner_ctx is used during context switch to decide if it needs
to load the saved registers or if the currently loaded registers are
valid. It could be skipped during a

  taskA -> kernel thread -> taskA

switch because the switch to the kernel thread would not alter the CPU's
sFPU tate.

Since this field is always updated during context switch and
never invalidated, setting it manually (in user context) makes no
difference. A kernel thread with kernel_fpu_begin() block could
set fpu_fpregs_owner_ctx to NULL but a kernel thread does not use
user_fpu_begin().

This is a leftover from the lazy-FPU time.

Remove user_fpu_begin(), it does not change fpu_fpregs_owner_ctx's
content.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aubrey Li <aubrey.li@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Nicolai Stange <nstange@suse.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-9-bigeasy@linutronix.de

The struct fpu.initialized member is always set to one for user tasks
and zero for kernel tasks. This avoids saving/restoring the FPU
registers for kernel threads.

The ->initialized = 0 case for user tasks has been removed in previous
changes, for instance, by doing an explicit unconditional init at fork()
time for FPU-less systems which was otherwise delayed until the emulated
opcode.

The context switch code (switch_fpu_prepare() + switch_fpu_finish())
can't unconditionally save/restore registers for kernel threads. Not
only would it slow down the switch but also load a zeroed xcomp_bv for
XSAVES.

For kernel_fpu_begin() (+end) the situation is similar: EFI with runtime
services uses this before alternatives_patched is true. Which means that
this function is used too early and it wasn't the case before.

For those two cases, use current->mm to distinguish between user and
kernel thread. For kernel_fpu_begin() skip save/restore of the FPU
registers.

During the context switch into a kernel thread don't do anything. There
is no reason to save the FPU state of a kernel thread.

The reordering in __switch_to() is important because the current()
pointer needs to be valid before switch_fpu_finish() is invoked so ->mm
is seen of the new task instead the old one.

N.B.: fpu__save() doesn't need to check ->mm because it is called by
user tasks only.

 [ bp: Massage. ]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aubrey Li <aubrey.li@intel.com>
Cc: Babu Moger <Babu.Moger@amd.com>
Cc: "Chang S. Bae" <chang.seok.bae@intel.com>
Cc: Dmitry Safonov <dima@arista.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Nicolai Stange <nstange@suse.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-8-bigeasy@linutronix.de

In commit

  72a671ce ("x86, fpu: Unify signal handling code paths for x86 and x86_64 kernels")

the 32bit and 64bit path of the signal delivery code were merged.

The 32bit version:

  int save_i387_xstate_ia32(void __user *buf)
  …
         if (cpu_has_xsave)
                 return save_i387_xsave(fp);
         if (cpu_has_fxsr)
                 return save_i387_fxsave(fp);

The 64bit version:

  int save_i387_xstate(void __user *buf)
  …
         if (user_has_fpu()) {
                 if (use_xsave())
                         err = xsave_user(buf);
                 else
                         err = fxsave_user(buf);

                 if (unlikely(err)) {
                         __clear_user(buf, xstate_size);
                         return err;

The merge:

  int save_xstate_sig(void __user *buf, void __user *buf_fx, int size)
  …
         if (user_has_fpu()) {
                 /* Save the live register state to the user directly. */
                 if (save_user_xstate(buf_fx))
                         return -1;
                 /* Update the thread's fxstate to save the fsave header. */
                 if (ia32_fxstate)
                         fpu_fxsave(&tsk->thread.fpu);

I don't think that we needed to save the FPU registers to ->thread.fpu
because the registers were stored in buf_fx. Today the state will be
restored from buf_fx after the signal was handled (I assume that this
was also the case with lazy-FPU).

Since commit

  66463db4 ("x86, fpu: shift drop_init_fpu() from save_xstate_sig() to handle_signal()")

it is ensured that the signal handler starts with clear/fresh set of FPU
registers which means that the previous store is futile.

Remove the copy_fxregs_to_kernel() call because task's FPU state is
cleared later in handle_signal() via fpu__clear().
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-7-bigeasy@linutronix.de

With lazy-FPU support the (now named variable) ->initialized was set to
true if the CPU's FPU registers were holding a valid state of the
FPU registers for the active process. If it was set to false then the
FPU state was saved in fpu->state and the FPU was deactivated.

With lazy-FPU gone, ->initialized is always true for user threads and
kernel threads never call this function so ->initialized is always true
in copy_fpstate_to_sigframe().

The using_compacted_format() check is also a leftover from the lazy-FPU
time. In the

  ->initialized == false

case copy_to_user() would copy the compacted buffer while userland would
expect the non-compacted format instead. So in order to save the FPU
state in the non-compacted form it issues XSAVE to save the *current*
FPU state.

If the FPU is not enabled, the attempt raises the FPU trap, the trap
restores the FPU contents and re-enables the FPU and XSAVE is invoked
again and succeeds.

*This* does not longer work since commit

  bef8b6da ("x86/fpu: Handle #NM without FPU emulation as an error")

Remove the check for ->initialized because it is always true and remove
the false condition. Update the comment to reflect that the state is
always live.

 [ bp: Massage. ]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-6-bigeasy@linutronix.de

fpu__clear() only initializes the state if the CPU has FPU support.
This initialisation is also required for FPU-less systems and takes
place in math_emulate(). Since fpu__initialize() only performs the
initialization if ->initialized is zero it does not matter that it
is invoked each time an opcode is emulated. It makes the removal of
->initialized easier if the struct is also initialized in the FPU-less
case at the same time.

Move fpu__initialize() before the FPU feature check so it is also
performed in the FPU-less case too.

 [ bp: Massage a bit. ]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aubrey Li <aubrey.li@intel.com>
Cc: Bill Metzenthen <billm@melbpc.org.au>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Nicolai Stange <nstange@suse.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-5-bigeasy@linutronix.de

The preempt_disable() section was introduced in commit

  a10b6a16 ("x86/fpu: Make the fpu state change in fpu__clear() scheduler-atomic")

and it was said to be temporary.

fpu__initialize() initializes the FPU struct to its initial value and
then sets ->initialized to 1. The last part is the important one.
The content of the state does not matter because it gets set via
copy_init_fpstate_to_fpregs().

A preemption here has little meaning because the registers will always be
set to the same content after copy_init_fpstate_to_fpregs(). A softirq
with a kernel_fpu_begin() could also force to save FPU's registers after
fpu__initialize() without changing the outcome here.

Remove the preempt_disable() section in fpu__clear(), preemption here
does not hurt.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Nicolai Stange <nstange@suse.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-4-bigeasy@linutronix.de

There are no users of fpu__restore() so it is time to remove it. The
comment regarding fpu__restore() and TS bit is stale since commit

  b3b0870e ("i387: do not preload FPU state at task switch time")

and has no meaning since.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aubrey Li <aubrey.li@intel.com>
Cc: Babu Moger <Babu.Moger@amd.com>
Cc: "Chang S. Bae" <chang.seok.bae@intel.com>
Cc: Dmitry Safonov <dima@arista.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: linux-doc@vger.kernel.org
Cc: Nicolai Stange <nstange@suse.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-3-bigeasy@linutronix.de

This is a preparation for the removal of the ->initialized member in the
fpu struct.

__fpu__restore_sig() is deactivating the FPU via fpu__drop() and then
setting manually ->initialized followed by fpu__restore(). The result is
that it is possible to manipulate fpu->state and the state of registers
won't be saved/restored on a context switch which would overwrite
fpu->state:

fpu__drop(fpu):
  ...
  fpu->initialized = 0;
  preempt_enable();

  <--- context switch

Don't access the fpu->state while the content is read from user space
and examined/sanitized. Use a temporary kmalloc() buffer for the
preparation of the FPU registers and once the state is considered okay,
load it. Should something go wrong, return with an error and without
altering the original FPU registers.

The removal of fpu__initialize() is a nop because fpu->initialized is
already set for the user task.

 [ bp: Massage a bit. ]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-2-bigeasy@linutronix.de

In save_xstate_epilog(), use __user when type-casting userspace
pointers.

In setup_sigcontext() and x32_setup_rt_frame(), cast the userspace
pointers to 'unsigned long __user *' before writing into them. These
pointers are originally '__u32 __user *' or '__u64 __user *', causing
sparse to complain when a userspace pointer is written into them. The
casts are okay because the pointers always point to pointer-sized
values.

Thanks to Luc Van Oostenryck and Al Viro for explaining this to me.
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mukesh Ojha <mojha@codeaurora.org>
Cc: Qiaowei Ren <qiaowei.ren@intel.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190329214652.258477-3-jannh@google.com

Pull KVM fixes from Paolo Bonzini:
 "A collection of x86 and ARM bugfixes, and some improvements to
  documentation.

  On top of this, a cleanup of kvm_para.h headers, which were exported
  by some architectures even though they not support KVM at all. This is
  responsible for all the Kbuild changes in the diffstat"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (28 commits)
  Documentation: kvm: clarify KVM_SET_USER_MEMORY_REGION
  KVM: doc: Document the life cycle of a VM and its resources
  KVM: selftests: complete IO before migrating guest state
  KVM: selftests: disable stack protector for all KVM tests
  KVM: selftests: explicitly disable PIE for tests
  KVM: selftests: assert on exit reason in CR4/cpuid sync test
  KVM: x86: update %rip after emulating IO
  x86/kvm/hyper-v: avoid spurious pending stimer on vCPU init
  kvm/x86: Move MSR_IA32_ARCH_CAPABILITIES to array emulated_msrs
  KVM: x86: Emulate MSR_IA32_ARCH_CAPABILITIES on AMD hosts
  kvm: don't redefine flags as something else
  kvm: mmu: Used range based flushing in slot_handle_level_range
  KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported
  KVM: x86: remove check on nr_mmu_pages in kvm_arch_commit_memory_region()
  kvm: nVMX: Add a vmentry check for HOST_SYSENTER_ESP and HOST_SYSENTER_EIP fields
  KVM: SVM: Workaround errata#1096 (insn_len maybe zero on SMAP violation)
  KVM: Reject device ioctls from processes other than the VM's creator
  KVM: doc: Fix incorrect word ordering regarding supported use of APIs
  KVM: x86: fix handling of role.cr4_pae and rename it to 'gpte_size'
  KVM: nVMX: Do not inherit quadrant and invalid for the root shadow EPT
  ...

Pull x86 fixes from Thomas Gleixner:
 "A pile of x86 updates:

   - Prevent exceeding he valid physical address space in the /dev/mem
     limit checks.

   - Move all header content inside the header guard to prevent compile
     failures.

   - Fix the bogus __percpu annotation in this_cpu_has() which makes
     sparse very noisy.

   - Disable switch jump tables completely when retpolines are enabled.

   - Prevent leaking the trampoline address"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/realmode: Make set_real_mode_mem() static inline
  x86/cpufeature: Fix __percpu annotation in this_cpu_has()
  x86/mm: Don't exceed the valid physical address space
  x86/retpolines: Disable switch jump tables when retpolines are enabled
  x86/realmode: Don't leak the trampoline kernel address
  x86/boot: Fix incorrect ifdeffery scope
  x86/resctrl: Remove unused variable

Pull perf tooling fixes from Thomas Gleixner:
 "Core libraries:
   - Fix max perf_event_attr.precise_ip detection.
   - Fix parser error for uncore event alias
   - Fixup ordering of kernel maps after obtaining the main kernel map
     address.

  Intel PT:
   - Fix TSC slip where A TSC packet can slip past MTC packets so that
     the timestamp appears to go backwards.
   - Fixes for exported-sql-viewer GUI conversion to python3.

  ARM coresight:
   - Fix the build by adding a missing case value for enumeration value
     introduced in newer library, that now is the required one.

  tool headers:
   - Syncronize kernel headers with the kernel, getting new io_uring and
     pidfd_send_signal syscalls so that 'perf trace' can handle them"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf pmu: Fix parser error for uncore event alias
  perf scripts python: exported-sql-viewer.py: Fix python3 support
  perf scripts python: exported-sql-viewer.py: Fix never-ending loop
  perf machine: Update kernel map address and re-order properly
  tools headers uapi: Sync powerpc's asm/kvm.h copy with the kernel sources
  tools headers: Update x86's syscall_64.tbl and uapi/asm-generic/unistd
  tools headers uapi: Update drm/i915_drm.h
  tools arch x86: Sync asm/cpufeatures.h with the kernel sources
  tools headers uapi: Sync linux/fcntl.h to get the F_SEAL_FUTURE_WRITE addition
  tools headers uapi: Sync asm-generic/mman-common.h and linux/mman.h
  perf evsel: Fix max perf_event_attr.precise_ip detection
  perf intel-pt: Fix TSC slip
  perf cs-etm: Add missing case value

Pull CPU hotplug fixes from Thomas Gleixner:
 "Two SMT/hotplug related fixes:

   - Prevent crash when HOTPLUG_CPU is disabled and the CPU bringup
     aborts. This is triggered with the 'nosmt' command line option, but
     can happen by any abort condition. As the real unplug code is not
     compiled in, prevent the fail by keeping the CPU in zombie state.

   - Enforce HOTPLUG_CPU for SMP on x86 to avoid the above situation
     completely. With 'nosmt' being a popular option it's required to
     unplug the half brought up sibling CPUs (due to the MCE wreckage)
     completely"

* 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/smp: Enforce CONFIG_HOTPLUG_CPU when SMP=y
  cpu/hotplug: Prevent crash when CPU bringup fails on CONFIG_HOTPLUG_CPU=n

Pull locking fixlet from Thomas Gleixner:
 "Trivial update to the maintainers file"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  MAINTAINERS: Remove deleted file from futex file pattern

Pull core fixes from Thomas Gleixner:
 "A small set of core updates:

   - Make the watchdog respect the selected CPU mask again. That was
     broken by the rework of the watchdog thread management and caused
     inconsistent state and NMI watchdog being unstoppable.

   - Ensure that the objtool build can find the libelf location.

   - Remove dead kcore stub code"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  watchdog: Respect watchdog cpumask on CPU hotplug
  objtool: Query pkg-config for libelf location
  proc/kcore: Remove unused kclist_add_remap()

Pull powerpc fixes from Michael Ellerman:
 "Three non-regression fixes.

   - Our optimised memcmp could read past the end of one of the buffers
     and potentially trigger a page fault leading to an oops.

   - Some of our code to read energy management data on PowerVM had an
     endian bug leading to bogus results.

   - When reporting a machine check exception we incorrectly reported
     TLB multihits as D-Cache multhits due to a missing entry in the
     array of causes.

  Thanks to: Chandan Rajendra, Gautham R. Shenoy, Mahesh Salgaonkar,
  Segher Boessenkool, Vaidyanathan Srinivasan"

* tag 'powerpc-5.1-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/pseries/mce: Fix misleading print for TLB mutlihit
  powerpc/pseries/energy: Use OF accessor functions to read ibm,drc-indexes
  powerpc/64: Fix memcmp reading past the end of src/dest

Pull dmaengine fixes from Vinod Koul:

 - Revert "dmaengine: stm32-mdma: Add a check on read_u32_array" as that
   caused regression

 - Fix MAINTAINER file uniphier-mdmac.c file path

* tag 'dmaengine-fix-5.1-rc3' of git://git.infradead.org/users/vkoul/slave-dma:
  MAINTAINERS: Fix uniphier-mdmac.c file path
  dmaengine: stm32-mdma: Revert "dmaengine: stm32-mdma: Add a check on read_u32_array"

Merge tag 'led-fixes-for-5.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds

Pull LED fixes from Jacek Anaszewski:

 - fix refcnt leak on interface rename

 - use memcpy in device_name_store() to avoid including garbage from a
   previous, longer value in the device_name

 - fix a potential NULL pointer dereference in case of_match_device()
   cannot find a match

* tag 'led-fixes-for-5.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds:
  leds: trigger: netdev: use memcpy in device_name_store
  leds: pca9532: fix a potential NULL pointer dereference
  leds: trigger: netdev: fix refcnt leak on interface rename

Pull GPIO fixes from Linus Walleij:
 "As you can see [in the git history] I was away on leave and Bartosz
  kindly stepped in and collected a slew of fixes, I pulled them into my
  tree in two sets and merged some two more fixes (fixing my own caused
  bugs) on top.

  Summary:

   - Revert the extended use of gpio_set_config() and think about how we
     can do this properly.

   - Fix up the SPI CS GPIO handling so it now works properly on the SPI
     bus children, as intended.

   - Error paths and driver fixes"

* tag 'gpio-v5.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
  gpio: mockup: use simple_read_from_buffer() in debugfs read callback
  gpio: of: Fix of_gpiochip_add() error path
  gpio: of: Check for "spi-cs-high" in child instead of parent node
  gpio: of: Check propname before applying "cs-gpios" quirks
  gpio: mockup: fix debugfs read
  Revert "gpio: use new gpio_set_config() helper in more places"
  gpio: aspeed: fix a potential NULL pointer dereference
  gpio: amd-fch: Fix bogus SPDX identifier
  gpio: adnp: Fix testing wrong value in adnp_gpio_direction_input
  gpio: exar: add a check for the return value of ida_simple_get fails

If userspace doesn't end the input with a newline (which can easily
happen if the write happens from a C program that does write(fd,
iface, strlen(iface))), we may end up including garbage from a
previous, longer value in the device_name. For example

# cat device_name

# printf 'eth12' > device_name
# cat device_name
eth12
# printf 'eth3' > device_name
# cat device_name
eth32

I highly doubt anybody is relying on this behaviour, so switch to
simply copying the bytes (we've already checked that size is <
IFNAMSIZ) and unconditionally zero-terminate it; of course, we also
still have to strip a trailing newline.

This is also preparation for future patches.

Fixes: 06f502f5 ("leds: trigger: Introduce a NETDEV trigger")
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>

In case of_match_device cannot find a match, return -EINVAL to avoid
NULL pointer dereference.

Fixes: fa4191a6 ("leds: pca9532: Add device tree support")
Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>

Pull staging driver fixes from Greg KH:
 "Here are some small staging driver fixes for 5.1-rc3, and one driver
  removal.

  The biggest thing here is the removal of the mt7621-eth driver as a
  "real" network driver was merged in 5.1-rc1 for this hardware, so this
  old driver can now be removed.

  Other than that, there are just a number of small fixes, all resolving
  reported issues and some potential corner cases for error handling
  paths.

  All of these have been in linux-next with no reported issues"

* tag 'staging-5.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging: vt6655: Remove vif check from vnt_interrupt
  staging: erofs: keep corrupted fs from crashing kernel in erofs_readdir()
  staging: octeon-ethernet: fix incorrect PHY mode
  staging: vc04_services: Fix an error code in vchiq_probe()
  staging: erofs: fix error handling when failed to read compresssed data
  staging: vt6655: Fix interrupt race condition on device start up.
  staging: rtlwifi: Fix potential NULL pointer dereference of kzalloc
  staging: rtl8712: uninitialized memory in read_bbreg_hdl()
  staging: rtlwifi: rtl8822b: fix to avoid potential NULL pointer dereference
  staging: rtl8188eu: Fix potential NULL pointer dereference of kcalloc
  staging, mt7621-pci: fix build without pci support
  staging: speakup_soft: Fix alternate speech with other synths
  staging: axis-fifo: add CONFIG_OF dependency
  staging: olpc_dcon_xo_1: add missing 'const' qualifier
  staging: comedi: ni_mio_common: Fix divide-by-zero for DIO cmdtest
  staging: erofs: fix to handle error path of erofs_vmap()
  staging: mt7621-dts: update ethernet settings.
  staging: remove mt7621-eth

Pull tty/serial fixes from Greg KH:
 "Here are some small tty and serial driver fixes for 5.1-rc3.

  Nothing major here, just a number of potential problems fixes for
  error handling paths, as well as some other minor bugfixes for
  reported issues with 5.1-rc1.

  All of these have been in linux-next with no reported issues"

* tag 'tty-5.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  tty: fix NULL pointer issue when tty_port ops is not set
  Disable kgdboc failed by echo space to /sys/module/kgdboc/parameters/kgdboc
  dt-bindings: serial: Add compatible for Mediatek MT8183
  tty/serial: atmel: RS485 HD w/DMA: enable RX after TX is stopped
  tty/serial: atmel: Add is_half_duplex helper
  serial: sh-sci: Fix setting SCSCR_TIE while transferring data
  serial: ar933x_uart: Fix build failure with disabled console
  tty: serial: qcom_geni_serial: Initialize baud in qcom_geni_console_setup
  sc16is7xx: missing unregister/delete driver on error in sc16is7xx_init()
  tty: mxs-auart: fix a potential NULL pointer dereference
  tty: atmel_serial: fix a potential NULL pointer dereference
  serial: max310x: Fix to avoid potential NULL pointer dereference
  serial: mvebu-uart: Fix to avoid a potential NULL pointer dereference

Pull USB fixes from Greg KH:
 "Here are some small USB fixes for 5.1-rc3.

  Nothing major at all here, just a small collection of fixes for
  reported issues, and potential problems with error handling paths.
  Also a few new device ids, as normal.

  All of these have been in linux-next with no reported issues"

* tag 'usb-5.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (25 commits)
  USB: serial: option: add Olicard 600
  USB: serial: cp210x: add new device id
  usb: u132-hcd: fix resource leak
  usb: cdc-acm: fix race during wakeup blocking TX traffic
  usb: mtu3: fix EXTCON dependency
  usb: usb251xb: fix to avoid potential NULL pointer dereference
  usb: core: Try generic PHY_MODE_USB_HOST if usb_phy_roothub_set_mode fails
  phy: sun4i-usb: Support set_mode to USB_HOST for non-OTG PHYs
  xhci: Don't let USB3 ports stuck in polling state prevent suspend
  usb: xhci: dbc: Don't free all memory with spinlock held
  xhci: Fix port resume done detection for SS ports with LPM enabled
  USB: serial: mos7720: fix mos_parport refcount imbalance on error path
  USB: gadget: f_hid: fix deadlock in f_hidg_write()
  usb: gadget: net2272: Fix net2272_dequeue()
  usb: gadget: net2280: Fix net2280_dequeue()
  usb: gadget: net2280: Fix overrun of OUT messages
  usb: dwc3: pci: add support for Comet Lake PCH ID
  usb: usb251xb: Remove unnecessary comparison of unsigned integer with >= 0
  usb: common: Consider only available nodes for dr_mode
  usb: typec: tcpm: Try PD-2.0 if sink does not respond to 3.0 source-caps
  ...

Pull ACPI fix from Rafael Wysocki:
 "This corrects a previous attempt to make Linux use its own set of ACPI
  debug flags different from the upstream ACPICA's default (Erik
  Schmauss)"

* tag 'acpi-5.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI: use different default debug value than ACPICA

Pull power management fixes from Rafael Wysocki:
 "These fix CPU base frequency reporting in the intel_pstate driver and
  a use-after-free in the scpi-cpufreq driver.

  Specifics:

   - Fix the ACPI CPPC library to actually follow the specification when
     decoding the guaranteed performance register information and make
     the intel_pstate driver to fall back to the nominal frequency when
     reporting the base frequency if the guaranteed performance register
     information is not there (Srinivas Pandruvada).

   - Fix use-after-free in the exit callback of the scpi-cpufreq left
     after an update during the 5.0 development cycle (Vincent Stehlé)"

* tag 'pm-5.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: scpi: Fix use after free
  cpufreq: intel_pstate: Also use CPPC nominal_perf for base_frequency
  ACPI / CPPC: Fix guaranteed performance handling

Pull security layer fixes from James Morris:
 "Yama and LSM config fixes"

* 'fixes-v5.1-a' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  LSM: Revive CONFIG_DEFAULT_SECURITY_* for "make oldconfig"
  Yama: mark local symbols as static

Merge misc fixes from Andrew Morton:
 "22 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (22 commits)
  fs/proc/proc_sysctl.c: fix NULL pointer dereference in put_links
  fs: fs_parser: fix printk format warning
  checkpatch: add %pt as a valid vsprintf extension
  mm/migrate.c: add missing flush_dcache_page for non-mapped page migrate
  drivers/block/zram/zram_drv.c: fix idle/writeback string compare
  mm/page_isolation.c: fix a wrong flag in set_migratetype_isolate()
  mm/memory_hotplug.c: fix notification in offline error path
  ptrace: take into account saved_sigmask in PTRACE{GET,SET}SIGMASK
  fs/proc/kcore.c: make kcore_modules static
  include/linux/list.h: fix list_is_first() kernel-doc
  mm/debug.c: fix __dump_page when mapping->host is not set
  mm: mempolicy: make mbind() return -EIO when MPOL_MF_STRICT is specified
  include/linux/hugetlb.h: convert to use vm_fault_t
  iommu/io-pgtable-arm-v7s: request DMA32 memory, and improve debugging
  mm: add support for kmem caches in DMA32 zone
  ocfs2: fix inode bh swapping mixup in ocfs2_reflink_inodes_lock
  mm/hotplug: fix offline undo_isolate_page_range()
  fs/open.c: allow opening only regular files during execve()
  mailmap: add Changbin Du
  mm/debug.c: add a cast to u64 for atomic64_read()
  ...

Pull arm64 fix from Catalin Marinas:
 "Use memblock_alloc() instead of memblock_alloc_low() in
  request_standard_resources(), the latter being limited to the low 4G
  memory range on arm64"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: replace memblock_alloc_low with memblock_alloc

Pull IOMMU fixes from Joerg Roedel:

 - Fix a bug in the AMD IOMMU driver not handling exclusion ranges
   correctly. In fact the driver did not reserve these ranges for IOVA
   allocations, so that dma-handles could be allocated in an exclusion
   range, leading to data corruption. Exclusion ranges have not been
   used by any firmware up to now, so this issue remained undiscovered
   for quite some time.

 - Fix wrong warning messages that the IOMMU core code prints when it
   tries to allocate the default domain for an iommu group and the
   driver does not support any of the default domain types (like Intel
   VT-d).

* tag 'iommu-fixes-v5.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/amd: Reserve exclusion range in iova-domain
  iommu: Don't print warning when IOMMU driver only supports unmanaged domains

Pull driver core fix from Greg KH:
 "Here is a single driver core patch for 5.1-rc3.

  After 5.1-rc1, all of the users of BUS_ATTR() are finally removed, so
  we can now drop this macro from include/linux/device.h so that no more
  new users will be created.

  This patch has been in linux-next for a while, with no reported
  issues"

* tag 'driver-core-5.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  driver core: remove BUS_ATTR()

Pull char/misc driver fixes from Greg KH:
 "Here are some binder, habanalabs, and vboxguest driver fixes for
  5.1-rc3.

  The Binder fixes resolve some reported issues found by testing, first
  by the selinux developers, and then earlier today by syzbot.

  The habanalabs fixes are all minor, resolving a number of tiny things.

  The vboxguest patches are a bit larger. They resolve the fact that
  virtual box decided to change their api in their latest release in a
  way that broke the existing kernel code, despite saying that they were
  never going to do that. So this is a bit of a "new feature", but is
  good to get merged so that 5.1 will work with the latest release. The
  changes are not large and of course virtual box "swears" they will not
  break this again, but no one is holding their breath here.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'char-misc-5.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  virt: vbox: Implement passing requestor info to the host for VirtualBox 6.0.x
  binder: fix race between munmap() and direct reclaim
  binder: fix BUG_ON found by selinux-testsuite
  habanalabs: cast to expected type
  habanalabs: prevent host crash during suspend/resume
  habanalabs: perform accounting for active CS
  habanalabs: fix mapping with page size bigger than 4KB
  habanalabs: complete user context cleanup before hard reset
  habanalabs: fix bug when mapping very large memory area
  habanalabs: fix MMU number of pages calculation

Pull SCSI fixes from James Bottomley:
 "Thirteen fixes, seven of which are for IBM fibre channel and three
  additional for fairly serious bugs in drivers (qla2xxx, mpt3sas,
  aacraid).

  Of the three core fixes, the most significant is probably the missed
  run queue causing an indefinite hang. The others are fixing a
  potential use after free on device close and silencing an incorrect
  warning"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: ibmvfc: Clean up transport events
  scsi: ibmvfc: Byte swap status and error codes when logging
  scsi: ibmvfc: Add failed PRLI to cmd_status lookup array
  scsi: ibmvfc: Remove "failed" from logged errors
  scsi: zfcp: reduce flood of fcrscn1 trace records on multi-element RSCN
  scsi: zfcp: fix scsi_eh host reset with port_forced ERP for non-NPIV FCP devices
  scsi: zfcp: fix rport unblock if deleted SCSI devices on Scsi_Host
  scsi: sd: Quiesce warning if device does not report optimal I/O size
  scsi: sd: Fix a race between closing an sd device and sd I/O
  scsi: core: Run queue when state is set to running after being blocked
  scsi: qla4xxx: fix a potential NULL pointer dereference
  scsi: aacraid: Insure we don't access PCIe space during AER/EEH
  scsi: mpt3sas: Fix kernel panic during expander reset

Pull i2c fixes from Wolfram Sang:
 "A new ID for the i801 driver and some Documentation fixes to make it
  easier for people to find the bindings (which is also a basis for
  further improvements in that area)"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: wmt: make bindings file name match the driver
  i2c: sun6i-p2wi: make bindings file name match the driver
  i2c: stu300: make bindings file name match the driver
  i2c: mt65xx: make bindings file name match the driver
  i2c: iop3xx: make bindings file name match the driver
  i2c: i801: Add support for Intel Comet Lake