linux.git/arch/x86/entry, branch v4.16

Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2018-03-25T17:36:02+00:00

Pull x86 and PTI fixes from Ingo Molnar:
 "Misc fixes:

   - fix EFI pagetables freeing

   - fix vsyscall pagetable setting on Xen PV guests

   - remove ancient CONFIG_X86_PPRO_FENCE=y - x86 is TSO again

   - fix two binutils (ld) development version related incompatibilities

   - clean up breakpoint handling

   - fix an x86 self-test"

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/entry/64: Don't use IST entry for #BP stack
  x86/efi: Free efi_pgd with free_pages()
  x86/vsyscall/64: Use proper accessor to update P4D entry
  x86/cpu: Remove the CONFIG_X86_PPRO_FENCE=y quirk
  x86/boot/64: Verify alignment of the LOAD segment
  x86/build/64: Force the linker to use 2MB page size
  selftests/x86/ptrace_syscall: Fix for yet more glibc interference

x86/entry/64: Don't use IST entry for #BP stack

2018-03-23T20:10:36+00:00

There's nothing IST-worthy about #BP/int3.  We don't allow kprobes
in the small handful of places in the kernel that run at CPL0 with
an invalid stack, and 32-bit kernels have used normal interrupt
gates for #BP forever.

Furthermore, we don't allow kprobes in places that have usergs while
in kernel mode, so "paranoid" is also unnecessary.

Signed-off-by: Andy Lutomirski 
Signed-off-by: Linus Torvalds 
Signed-off-by: Thomas Gleixner 
Cc: stable@vger.kernel.org

x86/vsyscall/64: Use proper accessor to update P4D entry

2018-03-20T11:00:53+00:00

Writing to it directly does not work for Xen PV guests.

Fixes: 49275fef986a ("x86/vsyscall/64: Explicitly set _PAGE_USER in the pagetable hierarchy")
Signed-off-by: Boris Ostrovsky 
Signed-off-by: Thomas Gleixner 
Reviewed-by: Juergen Gross 
Acked-by: Andy Lutomirski 
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180319143154.3742-1-boris.ostrovsky@oracle.com
Signed-off-by: Ingo Molnar

x86/cpu: Remove the CONFIG_X86_PPRO_FENCE=y quirk

2018-03-20T09:01:05+00:00

There were only a few Pentium Pro multiprocessors systems where this
errata applied. They are more than 20 years old now, and we've slowly
dropped places which put the workarounds in and discouraged anyone
from enabling the workaround.

Get rid of it for good.

Tested-by: Tom Lendacky 
Signed-off-by: Christoph Hellwig 
Reviewed-by: Thomas Gleixner 
Reviewed-by: Konrad Rzeszutek Wilk 
Cc: David Woodhouse 
Cc: Joerg Roedel 
Cc: Jon Mason 
Cc: Linus Torvalds 
Cc: Muli Ben-Yehuda 
Cc: Peter Zijlstra 
Cc: iommu@lists.linux-foundation.org
Link: http://lkml.kernel.org/r/20180319103826.12853-2-hch@lst.de
Signed-off-by: Ingo Molnar

Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2018-03-11T21:59:23+00:00

Pull x86/pti updates from Thomas Gleixner:
 "Yet another pile of melted spectrum related updates:

   - Drop native vsyscall support finally as it causes more trouble than
     benefit.

   - Make microcode loading more robust. There were a few issues
     especially related to late loading which are now surfacing because
     late loading of the IB* microcodes addressing spectre issues has
     become more widely used.

   - Simplify and robustify the syscall handling in the entry code

   - Prevent kprobes on the entry trampoline code which lead to kernel
     crashes when the probe hits before CR3 is updated

   - Don't check microcode versions when running on hypervisors as they
     are considered as lying anyway.

   - Fix the 32bit objtool build and a coment typo"

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/kprobes: Fix kernel crash when probing .entry_trampoline code
  x86/pti: Fix a comment typo
  x86/microcode: Synchronize late microcode loading
  x86/microcode: Request microcode on the BSP
  x86/microcode/intel: Look into the patch cache first
  x86/microcode: Do not upload microcode if CPUs are offline
  x86/microcode/intel: Writeback and invalidate caches before updating microcode
  x86/microcode/intel: Check microcode revision before updating sibling threads
  x86/microcode: Get rid of struct apply_microcode_ctx
  x86/spectre_v2: Don't check microcode versions when running under hypervisors
  x86/vsyscall/64: Drop "native" vsyscalls
  x86/entry/64/compat: Save one instruction in entry_INT80_compat()
  x86/entry: Do not special-case clone(2) in compat entry
  x86/syscalls: Use COMPAT_SYSCALL_DEFINEx() macros for x86-only compat syscalls
  x86/syscalls: Use proper syscall definition for sys_ioperm()
  x86/entry: Remove stale syscall prototype
  x86/syscalls/32: Simplify $entry == $compat entries
  objtool: Fix 32-bit build

x86/vsyscall/64: Drop "native" vsyscalls

2018-03-08T05:48:15+00:00

Since Linux v3.2, vsyscalls have been deprecated and slow.  From v3.2
on, Linux had three vsyscall modes: "native", "emulate", and "none".

"emulate" is the default.  All known user programs work correctly in
emulate mode, but vsyscalls turn into page faults and are emulated.
This is very slow.  In "native" mode, the vsyscall page is easily
usable as an exploit gadget, but vsyscalls are a bit faster -- they
turn into normal syscalls.  (This is in contrast to vDSO functions,
which can be much faster than syscalls.)  In "none" mode, there are
no vsyscalls.

For all practical purposes, "native" was really just a chicken bit
in case something went wrong with the emulation.  It's been over six
years, and nothing has gone wrong.  Delete it.

Signed-off-by: Andy Lutomirski 
Acked-by: Kees Cook 
Acked-by: Linus Torvalds 
Cc: Borislav Petkov 
Cc: Dominik Brodowski 
Cc: Kernel Hardening 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/519fee5268faea09ae550776ce969fa6e88668b0.1520449896.git.luto@kernel.org
Signed-off-by: Ingo Molnar

x86/entry/64/compat: Save one instruction in entry_INT80_compat()

2018-03-07T06:57:31+00:00

As %rdi is never user except in the following push, there is no
need to restore %rdi to the original value.

Signed-off-by: Dominik Brodowski 
Acked-by: Linus Torvalds 
Acked-by: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Josh Poimboeuf 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: luto@amacapital.net
Cc: viro@zeniv.linux.org.uk
Signed-off-by: Ingo Molnar

x86/entry: Do not special-case clone(2) in compat entry

2018-03-07T06:57:31+00:00

With the CPU renaming registers on its own, and all the overhead of the
syscall entry/exit, it is doubtful whether the compiled output of

	mov	%r8, %rax
	mov	%rcx, %r8
	mov	%rax, %rcx
	jmpq	sys_clone

is measurably slower than the hand-crafted version of

	xchg	%r8, %rcx

So get rid of this special case.

Signed-off-by: Dominik Brodowski 
Acked-by: Linus Torvalds 
Acked-by: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Josh Poimboeuf 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: luto@amacapital.net
Cc: viro@zeniv.linux.org.uk
Signed-off-by: Ingo Molnar

x86/syscalls: Use COMPAT_SYSCALL_DEFINEx() macros for x86-only compat syscalls

2018-03-07T06:57:30+00:00

While at it, convert declarations of type "unsigned" to "unsigned int".

Signed-off-by: Dominik Brodowski 
Acked-by: Linus Torvalds 
Acked-by: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Josh Poimboeuf 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: luto@amacapital.net
Cc: viro@zeniv.linux.org.uk
Signed-off-by: Ingo Molnar

x86/syscalls/32: Simplify $entry == $compat entries

2018-03-07T06:57:29+00:00

If the compat entry point is equivalent to the native entry point, it
does not need to be specified explicitly.

Signed-off-by: Dominik Brodowski 
Acked-by: Linus Torvalds 
Acked-by: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Josh Poimboeuf 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: luto@amacapital.net
Cc: viro@zeniv.linux.org.uk
Signed-off-by: Ingo Molnar