Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Fix "BUG: using smp_processor_id() in preemptible" reported in accesses
to thread's FPU defaults: the value to initialise FSCR to at program
startup, the FCSR r/w mask and the contents of FIR in full FPU
emulation, removing a regression introduced with 9b26616c [MIPS: Respect
the ISA level in FCSR handling] and f6843626 [MIPS: math-emu: Set FIR
feature flags for full emulation].

Use `boot_cpu_data' to obtain the data from, following the approach that
`cpu_has_*' macros take and avoiding the call to `smp_processor_id' made
in the reference to `current_cpu_data'.  The contents of FSCR have to be
consistent across processors in an SMP system, the settings there must
not change as a thread is migrated across processors.  And the contents
of FIR are guaranteed to be consistent in FPU emulation, by definition.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Tested-by: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Tested-by: Paul Martin <paul.martin@codethink.co.uk>
Cc: Markos Chandras <Markos.Chandras@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/10030/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Define the central place the default FCSR value is set from, initialised
in `cpu_probe'.  Determine the FCSR mask applied to values written to
the register with CTC1 in the full emulation mode and via ptrace(2),
according to the ISA level of processor hardware or the writability of
bits 31:18 if actual FPU hardware is used.

Software may rely on FCSR bits whose functions our emulator does not
implement, so it should not allow them to be set or software may get
confused.  For ptrace(2) it's just sanity.

[ralf@linux-mips.org: Fixed double inclusion of <asm/current.h>.]

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9711/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

If a ptracee has not used the FPU and the ptracer sets its FP context
using PTRACE_POKEUSR, PTRACE_SETFPREGS or PTRACE_SETREGSET then that
context will be discarded upon either the ptracee using the FPU or a
further write to the context via ptrace. Prevent this loss by recording
that the task has "used" math once its FP context has been written to.
The context initialisation code that was present for the PTRACE_POKEUSR
case is reused for the other 2 cases to provide consistent behaviour
for the different ptrace requests.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9166/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Register 2 is alredy overwritten by the return value when
syscall_trace_leave() is called.

Signed-off-by: Lars Persson <larper@axis.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9187/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Pull audit updates from Eric Paris:
 "So this change across a whole bunch of arches really solves one basic
  problem.  We want to audit when seccomp is killing a process.  seccomp
  hooks in before the audit syscall entry code.  audit_syscall_entry
  took as an argument the arch of the given syscall.  Since the arch is
  part of what makes a syscall number meaningful it's an important part
  of the record, but it isn't available when seccomp shoots the
  syscall...

  For most arch's we have a better way to get the arch (syscall_get_arch)
  So the solution was two fold: Implement syscall_get_arch() everywhere
  there is audit which didn't have it.  Use syscall_get_arch() in the
  seccomp audit code.  Having syscall_get_arch() everywhere meant it was
  a useless flag on the stack and we could get rid of it for the typical
  syscall entry.

  The other changes inside the audit system aren't grand, fixed some
  records that had invalid spaces.  Better locking around the task comm
  field.  Removing some dead functions and structs.  Make some things
  static.  Really minor stuff"

* git://git.infradead.org/users/eparis/audit: (31 commits)
  audit: rename audit_log_remove_rule to disambiguate for trees
  audit: cull redundancy in audit_rule_change
  audit: WARN if audit_rule_change called illegally
  audit: put rule existence check in canonical order
  next: openrisc: Fix build
  audit: get comm using lock to avoid race in string printing
  audit: remove open_arg() function that is never used
  audit: correct AUDIT_GET_FEATURE return message type
  audit: set nlmsg_len for multicast messages.
  audit: use union for audit_field values since they are mutually exclusive
  audit: invalid op= values for rules
  audit: use atomic_t to simplify audit_serial()
  kernel/audit.c: use ARRAY_SIZE instead of sizeof/sizeof[0]
  audit: reduce scope of audit_log_fcaps
  audit: reduce scope of audit_net_id
  audit: arm64: Remove the audit arch argument to audit_syscall_entry
  arm64: audit: Add audit hook in syscall_trace_enter/exit()
  audit: x86: drop arch from __audit_syscall_entry() interface
  sparc: implement is_32bit_task
  sparc: properly conditionalize use of TIF_32BIT
  ...

We have a function where the arch can be queried, syscall_get_arch().
So rather than have every single piece of arch specific code use and/or
duplicate syscall_get_arch(), just have the audit code use the
syscall_get_arch() code.

Based-on-patch-by: Richard Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
Cc: linux-alpha@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-ia64@vger.kernel.org
Cc: microblaze-uclinux@itee.uq.edu.au
Cc: linux-mips@linux-mips.org
Cc: linux@lists.openrisc.net
Cc: linux-parisc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: sparclinux@vger.kernel.org
Cc: user-mode-linux-devel@lists.sourceforge.net
Cc: linux-xtensa@linux-xtensa.org
Cc: x86@kernel.org

The secure_computing function took a syscall number parameter, but
it only paid any attention to that parameter if seccomp mode 1 was
enabled.  Rather than coming up with a kludge to get the parameter
to work in mode 2, just remove the parameter.

To avoid churn in arches that don't have seccomp filters (and may
not even support syscall_get_nr right now), this leaves the
parameter in secure_computing_strict, which is now a real function.

For ARM, this is a bit ugly due to the fact that ARM conditionally
supports seccomp filters.  Fixing that would probably only be a
couple of lines of code, but it should be coordinated with the audit
maintainers.

This will be a slight slowdown on some arches.  The right fix is to
pass in all of seccomp_data instead of trying to make just the
syscall nr part be fast.

This is a prerequisite for making two-phase seccomp work cleanly.

Cc: Russell King <linux@arm.linux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux-s390@vger.kernel.org
Cc: x86@kernel.org
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Kees Cook <keescook@chromium.org>