commit 977a3009547dad4a5bc95d91be4a58c9f7eedac0 upstream.

Type 3 instruction fault (FPU insn with FPU disabled) is handled
by quietly enabling FPU and returning.  Which is fine, except that
we need to do that both for fault in userland and in the kernel;
the latter *can* legitimately happen - all it takes is this:

.global _start
_start:
        call_pal 0xae
	lda $0, 0
	ldq $0, 0($0)

- call_pal CLRFEN to clear "FPU enabled" flag and arrange for
a signal delivery (SIGSEGV in this case).

Fixed by moving the handling of type 3 into the common part of
do_entIF(), before we check for kernel vs. user mode.

Incidentally, the check for kernel mode is unidiomatic; the normal
way to do that is !user_mode(regs).  The difference is that
the open-coded variant treats any of bits 63..3 of regs->ps being
set as "it's user mode" while the normal approach is to check just
the bit 3.  PS is a 4-bit register and regs->ps always will have
bits 63..4 clear, so the open-coded variant here is actually equivalent
to !user_mode(regs).  Harder to follow, though...

Cc: stable@vger.kernel.org
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Pull alpha updates from Al Viro:
 "Alpha architecture cleanups and fixes.

  One thing *not* included is lazy FPU switching stuff - this pile is
  just the straightforward stuff"

* tag 'pull-alpha' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  alpha: ret_from_fork can go straight to ret_to_user
  alpha: syscall exit cleanup
  alpha: fix handling of a3 on straced syscalls
  alpha: fix syscall entry in !AUDUT_SYSCALL case
  alpha: _TIF_ALLWORK_MASK is unused
  alpha: fix TIF_NOTIFY_SIGNAL handling

Don't bother with pointless macros - we are not sharing it with aout coredumps
anymore.  Just convert the underlying functions to the same arguments (nobody
uses regs, actually) and call them elf_core_copy_task_fpregs().  And unexport
the entire bunch, while we are at it.

[added missing includes in arch/{csky,m68k,um}/kernel/process.c to avoid extra
warnings about the lack of externs getting added to huge piles for those
files.  Pointless, but...]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

We only hit ret_from_fork when the child is meant to return to
userland (since 2012 or so).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

$ret_success consists of two insn + branch to ret_from_syscall.
The thing is, those insns are identical to the ones immediately
preceding ret_from_syscall...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

For successful syscall that happens to return a negative, we want
a3 set to 0, no matter whether it's straced or not.  As it is,
for straced case we leave the value it used to have on syscall
entry.  Easily fixed, fortunately...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

We only want to take the slow path if SYSCALL_TRACE or SYSCALL_AUDIT is
set; on !AUDIT_SYSCALL configs the current tree hits it whenever _any_
thread flag (including NEED_RESCHED, NOTIFY_SIGNAL, etc.) happens to
be set.

Fixes: a9302e843944 "alpha: Enable system-call auditing support"
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Pull asm-generic fix from Arnd Bergmann:
 "A last-minute arch/alpha regression fix: the previous asm-generic
  branch contained a new regression from a typo"

* tag 'asm-generic-fixes-6.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
  alpha: fix marvel_ioread8 build regression

Pull non-MM updates from Andrew Morton:

 - hfs and hfsplus kmap API modernization (Fabio Francesco)

 - make crash-kexec work properly when invoked from an NMI-time panic
   (Valentin Schneider)

 - ntfs bugfixes (Hawkins Jiawei)

 - improve IPC msg scalability by replacing atomic_t's with percpu
   counters (Jiebin Sun)

 - nilfs2 cleanups (Minghao Chi)

 - lots of other single patches all over the tree!

* tag 'mm-nonmm-stable-2022-10-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (71 commits)
  include/linux/entry-common.h: remove has_signal comment of arch_do_signal_or_restart() prototype
  proc: test how it holds up with mapping'less process
  mailmap: update Frank Rowand email address
  ia64: mca: use strscpy() is more robust and safer
  init/Kconfig: fix unmet direct dependencies
  ia64: update config files
  nilfs2: replace WARN_ONs by nilfs_error for checkpoint acquisition failure
  fork: remove duplicate included header files
  init/main.c: remove unnecessary (void*) conversions
  proc: mark more files as permanent
  nilfs2: remove the unneeded result variable
  nilfs2: delete unnecessary checks before brelse()
  checkpatch: warn for non-standard fixes tag style
  usr/gen_init_cpio.c: remove unnecessary -1 values from int file
  ipc/msg: mitigate the lock contention with percpu counter
  percpu: add percpu_counter_add_local and percpu_counter_sub_local
  fs/ocfs2: fix repeated words in comments
  relay: use kvcalloc to alloc page array in relay_alloc_page_array
  proc: make config PROC_CHILDREN depend on PROC_FS
  fs: uninline inode_maybe_inc_iversion()
  ...

Commit 987f20a9dcce ("a.out: Remove the a.out implementation") removes
CONFIG_OSF4_COMPAT and its functionality. Hence, sys_osf_{readv,writev}
are now just aliases of sys_{readv,writev}.

Remove these needless aliases.

[ Identical patch also posted by Jason A. Donenfeld ]

Link: https://lore.kernel.org/lkml/CAHk-=wjwvBc3VQMNtUVUrMBVoMPSPu26OuatZ_+1gZ2m-PmmRA@mail.gmail.com/
Link: https://lore.kernel.org/all/20221004135301.1420873-1-Jason@zx2c4.com/
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>