This reverts commit 1dde7415e9. By putting
the RSB filling out of line and calling it, we waste one RSB slot for
returning from the function itself, which means one fewer actual function
call we can make if we're doing the Skylake abomination of call-depth
counting.
It also changed the number of RSB stuffings we do on vmexit from 32,
which was correct, to 16. Let's just stop with the bikeshedding; it
didn't actually *fix* anything anyway.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: arjan.van.de.ven@intel.com
Cc: bp@alien8.de
Cc: dave.hansen@intel.com
Cc: jmattson@google.com
Cc: karahmed@amazon.de
Cc: kvm@vger.kernel.org
Cc: pbonzini@redhat.com
Cc: rkrcmar@redhat.com
Link: http://lkml.kernel.org/r/1519037457-7643-4-git-send-email-dwmw@amazon.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Omitting suffixes from instructions in AT&T mode is bad practice when
operand size cannot be determined by the assembler from register
operands, and is likely going to be warned about by upstream GAS in the
future (mine does already). Add the single missing suffix here.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/5A8AF5F602000078001A9230@prv-mh.provo.novell.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
BUG() doesn't always imply "no return", and hence should be followed by
a return statement even if that's obviously (to a human) unreachable.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/5A8AF2AA02000078001A91E9@prv-mh.provo.novell.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit:
df3405245a ("x86/asm: Add suffix macro for GEN_*_RMWcc()")
... introduced "suffix" RMWcc operations, adding bogus clobber specifiers:
For one, on x86 there's no point explicitly clobbering "cc".
In fact, with GCC properly fixed, this results in an overlap being detected by
the compiler between outputs and clobbers.
Furthermore it seems bad practice to me to have clobber specification
and use of the clobbered register(s) disconnected - it should rather be
at the invocation place of that GEN_{UN,BIN}ARY_SUFFIXED_RMWcc() macros
that the clobber is specified which this particular invocation needs.
Drop the "cc" clobber altogether and move the "cx" one to refcount.h.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/5A8AF1F802000078001A91E1@prv-mh.provo.novell.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This comment referred to a conditional call to kmemcheck_hide() that was
here until commit 4950276672 ("kmemcheck: remove annotations").
Now that kmemcheck has been removed, it doesn't make sense anymore.
Signed-off-by: Jann Horn <jannh@google.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180219175039.253089-1-jannh@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Just like pte_{set,clear}_flags() their PMD and PUD counterparts should
not do any address translation. This was outright wrong under Xen
(causing a dead boot with no useful output on "suitable" systems), and
produced needlessly more complicated code (even if just slightly) when
paravirt was enabled.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/5A8AF1BB02000078001A91C3@prv-mh.provo.novell.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
On some x86 CPU microarchitectures using 'xorq' to clear general-purpose
registers is slower than 'xorl'. As 'xorl' is sufficient to clear all
64 bits of these registers due to zero-extension [*], switch the x86
64-bit entry code to use 'xorl'.
No change in functionality and no change in code size.
[*] According to Intel 64 and IA-32 Architecture Software Developer's
Manual, section 3.4.1.1, the result of 32-bit operands are "zero-
extended to a 64-bit result in the destination general-purpose
register." The AMD64 Architecture Programmer’s Manual Volume 3,
Appendix B.1, describes the same behaviour.
Suggested-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180214175924.23065-3-linux@dominikbrodowski.net
[ Improved on the changelog a bit. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Play a little trick in the generic PUSH_AND_CLEAR_REGS macro
to insert the GP registers "above" the original return address.
This allows us to (re-)insert the macro in error_entry() and
paranoid_entry() and to remove it from the idtentry macro. This
reduces the static footprint significantly:
text data bss dec hex filename
24307 0 0 24307 5ef3 entry_64.o-orig
20987 0 0 20987 51fb entry_64.o
Co-developed-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180214175924.23065-2-linux@dominikbrodowski.net
[ Small tweaks to comments. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
With some microcode upgrades, new CPUID features can become visible on
the CPU. Check what the kernel has mirrored now and issue a warning
hinting at possible things the user/admin can do to make use of the
newly visible features.
Originally-by: Ashok Raj <ashok.raj@intel.com>
Tested-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180216112640.11554-4-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add a callback function which the microcode loader calls when microcode
has been updated to a newer revision. Do the callback only when no error
was encountered during loading.
Tested-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180216112640.11554-3-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
... so that callers can know when microcode was updated and act
accordingly.
Tested-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180216112640.11554-2-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 PTI and Spectre related fixes and updates from Ingo Molnar:
"Here's the latest set of Spectre and PTI related fixes and updates:
Spectre:
- Add entry code register clearing to reduce the Spectre attack
surface
- Update the Spectre microcode blacklist
- Inline the KVM Spectre helpers to get close to v4.14 performance
again.
- Fix indirect_branch_prediction_barrier()
- Fix/improve Spectre related kernel messages
- Fix array_index_nospec_mask() asm constraint
- KVM: fix two MSR handling bugs
PTI:
- Fix a paranoid entry PTI CR3 handling bug
- Fix comments
objtool:
- Fix paranoid_entry() frame pointer warning
- Annotate WARN()-related UD2 as reachable
- Various fixes
- Add Add Peter Zijlstra as objtool co-maintainer
Misc:
- Various x86 entry code self-test fixes
- Improve/simplify entry code stack frame generation and handling
after recent heavy-handed PTI and Spectre changes. (There's two
more WIP improvements expected here.)
- Type fix for cache entries
There's also some low risk non-fix changes I've included in this
branch to reduce backporting conflicts:
- rename a confusing x86_cpu field name
- de-obfuscate the naming of single-TLB flushing primitives"
* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits)
x86/entry/64: Fix CR3 restore in paranoid_exit()
x86/cpu: Change type of x86_cache_size variable to unsigned int
x86/spectre: Fix an error message
x86/cpu: Rename cpu_data.x86_mask to cpu_data.x86_stepping
selftests/x86/mpx: Fix incorrect bounds with old _sigfault
x86/mm: Rename flush_tlb_single() and flush_tlb_one() to __flush_tlb_one_[user|kernel]()
x86/speculation: Add <asm/msr-index.h> dependency
nospec: Move array_index_nospec() parameter checking into separate macro
x86/speculation: Fix up array_index_nospec_mask() asm constraint
x86/debug: Use UD2 for WARN()
x86/debug, objtool: Annotate WARN()-related UD2 as reachable
objtool: Fix segfault in ignore_unreachable_insn()
selftests/x86: Disable tests requiring 32-bit support on pure 64-bit systems
selftests/x86: Do not rely on "int $0x80" in single_step_syscall.c
selftests/x86: Do not rely on "int $0x80" in test_mremap_vdso.c
selftests/x86: Fix build bug caused by the 5lvl test which has been moved to the VM directory
selftests/x86/pkeys: Remove unused functions
selftests/x86: Clean up and document sscanf() usage
selftests/x86: Fix vDSO selftest segfault for vsyscall=none
x86/entry/64: Remove the unused 'icebp' macro
...
Josh Poimboeuf noticed the following bug:
"The paranoid exit code only restores the saved CR3 when it switches back
to the user GS. However, even in the kernel GS case, it's possible that
it needs to restore a user CR3, if for example, the paranoid exception
occurred in the syscall exit path between SWITCH_TO_USER_CR3_STACK and
SWAPGS."
Josh also confirmed via targeted testing that it's possible to hit this bug.
Fix the bug by also restoring CR3 in the paranoid_exit_no_swapgs branch.
The reason we haven't seen this bug reported by users yet is probably because
"paranoid" entry points are limited to the following cases:
idtentry double_fault do_double_fault has_error_code=1 paranoid=2
idtentry debug do_debug has_error_code=0 paranoid=1 shift_ist=DEBUG_STACK
idtentry int3 do_int3 has_error_code=0 paranoid=1 shift_ist=DEBUG_STACK
idtentry machine_check do_mce has_error_code=0 paranoid=1
Amongst those entry points only machine_check is one that will interrupt an
IRQS-off critical section asynchronously - and machine check events are rare.
The other main asynchronous entries are NMI entries, which can be very high-freq
with perf profiling, but they are special: they don't use the 'idtentry' macro but
are open coded and restore user CR3 unconditionally so don't have this bug.
Reported-and-tested-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180214073910.boevmg65upbk3vqb@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Currently, x86_cache_size is of type int, which makes no sense as we
will never have a valid cache size equal or less than 0. So instead of
initializing this variable to -1, it can perfectly be initialized to 0
and use it as an unsigned variable instead.
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Addresses-Coverity-ID: 1464429
Link: http://lkml.kernel.org/r/20180213192208.GA26414@embeddedor.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
If i == ARRAY_SIZE(mitigation_options) then we accidentally print
garbage from one space beyond the end of the mitigation_options[] array.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: KarimAllah Ahmed <karahmed@amazon.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel-janitors@vger.kernel.org
Fixes: 9005c6834c ("x86/spectre: Simplify spectre_v2 command line parsing")
Link: http://lkml.kernel.org/r/20180214071416.GA26677@mwanda
Signed-off-by: Ingo Molnar <mingo@kernel.org>
x86_mask is a confusing name which is hard to associate with the
processor's stepping.
Additionally, correct an indent issue in lib/cpu.c.
Signed-off-by: Jia Zhang <qianyue.zj@alibaba-inc.com>
[ Updated it to more recent kernels. ]
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bp@alien8.de
Cc: tony.luck@intel.com
Link: http://lkml.kernel.org/r/1514771530-70829-1-git-send-email-qianyue.zj@alibaba-inc.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
flush_tlb_single() and flush_tlb_one() sound almost identical, but
they really mean "flush one user translation" and "flush one kernel
translation". Rename them to flush_tlb_one_user() and
flush_tlb_one_kernel() to make the semantics more obvious.
[ I was looking at some PTI-related code, and the flush-one-address code
is unnecessarily hard to understand because the names of the helpers are
uninformative. This came up during PTI review, but no one got around to
doing it. ]
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Linux-MM <linux-mm@kvack.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/3303b02e3c3d049dc5235d5651e0ae6d29a34354.1517414378.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Allow the compiler to handle @size as an immediate value or memory
directly rather than allocating a register.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/151797010204.1289.1510000292250184993.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Since the Intel SDM added an ModR/M byte to UD0 and binutils followed
that specification, we now cannot disassemble our kernel anymore.
This now means Intel and AMD disagree on the encoding of UD0. And instead
of playing games with additional bytes that are valid ModR/M and single
byte instructions (0xd6 for instance), simply use UD2 for both WARN() and
BUG().
Requested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180208194406.GD25181@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
By default, objtool assumes that a UD2 is a dead end. This is mainly
because GCC 7+ sometimes inserts a UD2 when it detects a divide-by-zero
condition.
Now that WARN() is moving back to UD2, annotate the code after it as
reachable so objtool can follow the code flow.
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kbuild test robot <fengguang.wu@intel.com>
Link: http://lkml.kernel.org/r/0e483379275a42626ba8898117f918e1bf661e40.1518130694.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
A larger batch of fixes than we'd like. Roughly 1/3 fixes for new code, 1/3
fixes for stable and 1/3 minor things.
There's four commits fixing bugs when using 16GB huge pages on hash, caused by
some of the preparatory changes for pkeys.
Two fixes for bugs in the enhanced IRQ soft masking for local_t, one of which
broke KVM in some circumstances.
Four fixes for Power9. The most bizarre being a bug where futexes stopped
working because a NULL pointer dereference didn't trap during early boot (it
aliased the kernel mapping). A fix for memory hotplug when using the Radix MMU,
and a fix for live migration of guests using the Radix MMU.
Two fixes for hotplug on pseries machines. One where we weren't correctly
updating NUMA info when CPUs are added and removed. And the other fixes
crashes/hangs seen when doing memory hot remove during boot, which is apparently
a thing people do.
Finally a handful of build fixes for obscure configs and other minor fixes.
Thanks to:
Alexey Kardashevskiy, Aneesh Kumar K.V, Balbir Singh, Colin Ian King, Daniel
Henrique Barboza, Florian Weimer, Guenter Roeck, Harish, Laurent Vivier,
Madhavan Srinivasan, Mauricio Faria de Oliveira, Nathan Fontenot, Nicholas
Piggin, Sam Bobroff.
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Merge tag 'powerpc-4.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
"A larger batch of fixes than we'd like. Roughly 1/3 fixes for new
code, 1/3 fixes for stable and 1/3 minor things.
There's four commits fixing bugs when using 16GB huge pages on hash,
caused by some of the preparatory changes for pkeys.
Two fixes for bugs in the enhanced IRQ soft masking for local_t, one
of which broke KVM in some circumstances.
Four fixes for Power9. The most bizarre being a bug where futexes
stopped working because a NULL pointer dereference didn't trap during
early boot (it aliased the kernel mapping). A fix for memory hotplug
when using the Radix MMU, and a fix for live migration of guests using
the Radix MMU.
Two fixes for hotplug on pseries machines. One where we weren't
correctly updating NUMA info when CPUs are added and removed. And the
other fixes crashes/hangs seen when doing memory hot remove during
boot, which is apparently a thing people do.
Finally a handful of build fixes for obscure configs and other minor
fixes.
Thanks to: Alexey Kardashevskiy, Aneesh Kumar K.V, Balbir Singh, Colin
Ian King, Daniel Henrique Barboza, Florian Weimer, Guenter Roeck,
Harish, Laurent Vivier, Madhavan Srinivasan, Mauricio Faria de
Oliveira, Nathan Fontenot, Nicholas Piggin, Sam Bobroff"
* tag 'powerpc-4.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
selftests/powerpc: Fix to use ucontext_t instead of struct ucontext
powerpc/kdump: Fix powernv build break when KEXEC_CORE=n
powerpc/pseries: Fix build break for SPLPAR=n and CPU hotplug
powerpc/mm/hash64: Zero PGD pages on allocation
powerpc/mm/hash64: Store the slot information at the right offset for hugetlb
powerpc/mm/hash64: Allocate larger PMD table if hugetlb config is enabled
powerpc/mm: Fix crashes with 16G huge pages
powerpc/mm: Flush radix process translations when setting MMU type
powerpc/vas: Don't set uses_vas for kernel windows
powerpc/pseries: Enable RAS hotplug events later
powerpc/mm/radix: Split linear mapping on hot-unplug
powerpc/64s/radix: Boot-time NULL pointer protection using a guard-PID
ocxl: fix signed comparison with less than zero
powerpc/64s: Fix may_hard_irq_enable() for PMI soft masking
powerpc/64s: Fix MASKABLE_RELON_EXCEPTION_HV_OOL macro
powerpc/numa: Invalidate numa_cpu_lookup_table on cpu remove
A single change (and associated DT binding update) to allow the address
of the MIPS Cluster Power Controller (CPC) to be chosen by DT, which
allows SMP to work on generic MIPS kernels where the bootloader hasn't
configured the CPC address (i.e. the new Ranchu platform).
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Merge tag 'mips_4.16_2' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/mips
Pull MIPS fix from James Hogan:
"A single change (and associated DT binding update) to allow the
address of the MIPS Cluster Power Controller (CPC) to be chosen by DT,
which allows SMP to work on generic MIPS kernels where the bootloader
hasn't configured the CPC address (i.e. the new Ranchu platform)"
* tag 'mips_4.16_2' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/mips:
MIPS: CPC: Map registers using DT in mips_cpc_default_phys_base()
dt-bindings: Document mti,mips-cpc binding
If KEXEC_CORE is not enabled, powernv builds fail as follows.
arch/powerpc/platforms/powernv/smp.c: In function 'pnv_smp_cpu_kill_self':
arch/powerpc/platforms/powernv/smp.c:236:4: error:
implicit declaration of function 'crash_ipi_callback'
Add dummy function calls, similar to kdump_in_progress(), to solve the
problem.
Fixes: 4145f35864 ("powernv/kdump: Fix cases where the kdump kernel can get HMI's")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Commit e67e02a544 ("powerpc/pseries: Fix cpu hotplug crash with
memoryless nodes") adds an unconditional call to
find_and_online_cpu_nid(), which is only declared if CONFIG_PPC_SPLPAR
is enabled. This results in the following build error if this is not
the case.
arch/powerpc/platforms/pseries/hotplug-cpu.o: In function `dlpar_online_cpu':
arch/powerpc/platforms/pseries/hotplug-cpu.c:369:
undefined reference to `.find_and_online_cpu_nid'
Follow the guideline provided by similar functions and provide a dummy
function if CONFIG_PPC_SPLPAR is not enabled. This also moves the
external function declaration into an include file where it should be.
Fixes: e67e02a544 ("powerpc/pseries: Fix cpu hotplug crash with memoryless nodes")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
[mpe: Change subject to emphasise the build fix]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
On powerpc we allocate page table pages from slab caches of different
sizes. Currently we have a constructor that zeroes out the objects when
we allocate them for the first time.
We expect the objects to be zeroed out when we free the the object
back to slab cache. This happens in the unmap path. For hugetlb pages
we call huge_pte_get_and_clear() to do that.
With the current configuration of page table size, both PUD and PGD
level tables are allocated from the same slab cache. At the PUD level,
we use the second half of the table to store the slot information. But
we never clear that when unmapping.
When such a freed object is then allocated for a PGD page, the second
half of the page table page will not be zeroed as expected. This
results in a kernel crash.
Fix it by always clearing PGD pages when they're allocated.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
[mpe: Change log wording and formatting, add whitespace]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The hugetlb pte entries are at the PMD and PUD level, so we can't use
PTRS_PER_PTE to find the second half of the page table. Use the right
offset for PUD/PMD to get to the second half of the table.
Fixes: bf9a95f9a6 ("powerpc: Free up four 64K PTE bits in 64K backed HPTE pages")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
We use the second half of the page table to store slot information, so we must
allocate it always if hugetlb is possible.
Fixes: bf9a95f9a6 ("powerpc: Free up four 64K PTE bits in 64K backed HPTE pages")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
To support memory keys, we moved the hash pte slot information to the
second half of the page table. This was ok with PTE entries at level
4 (PTE page) and level 3 (PMD). We already allocate larger page table
pages at those levels to accomodate extra details. For level 4 we
already have the extra space which was used to track 4k hash page
table entry details and at level 3 the extra space was allocated to
track the THP details.
With hugetlbfs PTE, we used this extra space at the PMD level to store
the slot details. But we also support hugetlbfs PTE at PUD level for
16GB pages and PUD level page didn't allocate extra space. This
resulted in memory corruption.
Fix this by allocating extra space at PUD level when HUGETLB is
enabled.
Fixes: bf9a95f9a6 ("powerpc: Free up four 64K PTE bits in 64K backed HPTE pages")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Radix guests do normally invalidate process-scoped translations when a
new pid is allocated but migrated guests do not invalidate these so
migrated guests crash sometime, especially easy to reproduce with
migration happening within first 10 seconds after the guest boot start
on the same machine.
This adds the "Invalidate process-scoped translations" flush to fix
radix guests migration.
Fixes: 2ee13be34b ("KVM: PPC: Book3S HV: Update kvmppc_set_arch_compat() for ISA v3.00")
Cc: stable@vger.kernel.org # v4.10+
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Tested-by: Laurent Vivier <lvivier@redhat.com>
Tested-by: Daniel Henrique Barboza <danielhb@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
cp_abort is only required for user windows, because kernel context
must not be preempted between a copy/paste pair.
Without this patch, the init task gets used_vas set when it runs the
nx842_powernv_init initcall, which opens windows for kernel usage.
used_vas is then never cleared anywhere, so it gets propagated into
all other tasks. It's a property of the address space, so it should
really be cleared when a new mm is created (or in dup_mmap if the
mmaps are marked as VM_DONTCOPY). For now we seem to have no such
driver, so leave that for another patch.
Fixes: 6c8e6bb2a5 ("powerpc/vas: Add support for user receive window")
Cc: stable@vger.kernel.org # v4.15+
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently if the kernel receives a memory hot-unplug event early
enough, it may get stuck in an infinite loop in
dissolve_free_huge_pages(). This appears as a stall just after:
pseries-hotplug-mem: Attempting to hot-remove XX LMB(s) at YYYYYYYY
It appears to be caused by "minimum_order" being uninitialized, due to
init_ras_IRQ() executing before hugetlb_init().
To correct this, extract the part of init_ras_IRQ() that enables
hotplug event processing and place it in the machine_late_initcall
phase, which is guaranteed to be after hugetlb_init() is called.
Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>
[mpe: Reorder the functions to make the diff readable]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
That macro was touched around 2.5.8 times, judging by the full history
linux repo, but it was unused even then. Get rid of it already.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux@dominikbrodowski.net
Link: http://lkml.kernel.org/r/20180212201318.GD14640@pd.tnic
Signed-off-by: Ingo Molnar <mingo@kernel.org>
With the following commit:
f09d160992d1 ("x86/entry/64: Get rid of the ALLOC_PT_GPREGS_ON_STACK and SAVE_AND_CLEAR_REGS macros")
... one of my suggested improvements triggered a frame pointer warning:
arch/x86/entry/entry_64.o: warning: objtool: paranoid_entry()+0x11: call without frame pointer save/setup
The warning is correct for the build-time code, but it's actually not
relevant at runtime because of paravirt patching. The paravirt swapgs
call gets replaced with either a SWAPGS instruction or NOPs at runtime.
Go back to the previous behavior by removing the ELF function annotation
for paranoid_entry() and adding an unwind hint, which effectively
silences the warning.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kbuild-all@01.org
Cc: tipbuild@zytor.com
Fixes: f09d160992d1 ("x86/entry/64: Get rid of the ALLOC_PT_GPREGS_ON_STACK and SAVE_AND_CLEAR_REGS macros")
Link: http://lkml.kernel.org/r/20180212174503.5acbymg5z6p32snu@treble
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Previously, error_entry() and paranoid_entry() saved the GP registers
onto stack space previously allocated by its callers. Combine these two
steps in the callers, and use the generic PUSH_AND_CLEAR_REGS macro
for that.
This adds a significant amount ot text size. However, Ingo Molnar points
out that:
"these numbers also _very_ significantly over-represent the
extra footprint. The assumptions that resulted in
us compressing the IRQ entry code have changed very
significantly with the new x86 IRQ allocation code we
introduced in the last year:
- IRQ vectors are usually populated in tightly clustered
groups.
With our new vector allocator code the typical per CPU
allocation percentage on x86 systems is ~3 device vectors
and ~10 fixed vectors out of ~220 vectors - i.e. a very
low ~6% utilization (!). [...]
The days where we allocated a lot of vectors on every
CPU and the compression of the IRQ entry code text
mattered are over.
- Another issue is that only a small minority of vectors
is frequent enough to actually matter to cache utilization
in practice: 3-4 key IPIs and 1-2 device IRQs at most - and
those vectors tend to be tightly clustered as well into about
two groups, and are probably already on 2-3 cache lines in
practice.
For the common case of 'cache cold' IRQs it's the depth of
the call chain and the fragmentation of the resulting I$
that should be the main performance limit - not the overall
size of it.
- The CPU side cost of IRQ delivery is still very expensive
even in the best, most cached case, as in 'over a thousand
cycles'. So much stuff is done that maybe contemporary x86
IRQ entry microcode already prefetches the IDT entry and its
expected call target address."[*]
[*] http://lkml.kernel.org/r/20180208094710.qnjixhm6hybebdv7@gmail.com
The "testb $3, CS(%rsp)" instruction in the idtentry macro does not need
modification. Previously, %rsp was manually decreased by 15*8; with
this patch, %rsp is decreased by 15 pushq instructions.
[jpoimboe@redhat.com: unwind hint improvements]
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dan.j.williams@intel.com
Link: http://lkml.kernel.org/r/20180211104949.12992-7-linux@dominikbrodowski.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
entry_SYSCALL_64_after_hwframe() and nmi() can be converted to use
PUSH_AND_CLEAN_REGS instead of opencoded variants thereof. Due to
the interleaving, the additional XOR-based clearing of R8 and R9
in entry_SYSCALL_64_after_hwframe() should not have any noticeable
negative implications.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dan.j.williams@intel.com
Link: http://lkml.kernel.org/r/20180211104949.12992-6-linux@dominikbrodowski.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Those instances where ALLOC_PT_GPREGS_ON_STACK is called just before
SAVE_AND_CLEAR_REGS can trivially be replaced by PUSH_AND_CLEAN_REGS.
This macro uses PUSH instead of MOV and should therefore be faster, at
least on newer CPUs.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dan.j.williams@intel.com
Link: http://lkml.kernel.org/r/20180211104949.12992-5-linux@dominikbrodowski.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Same as is done for syscalls, interleave XOR with PUSH instructions
for exceptions/interrupts, in order to minimize the cost of the
additional instructions required for register clearing.
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dan.j.williams@intel.com
Link: http://lkml.kernel.org/r/20180211104949.12992-4-linux@dominikbrodowski.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
All current code paths call SAVE_C_REGS and then immediately
SAVE_EXTRA_REGS. Therefore, merge these two macros and order the MOV
sequeneces properly.
While at it, remove the macros to save all except specific registers,
as these macros have been unused for a long time.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dan.j.williams@intel.com
Link: http://lkml.kernel.org/r/20180211104949.12992-2-linux@dominikbrodowski.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Harmonize all the Spectre messages so that a:
dmesg | grep -i spectre
... gives us most Spectre related kernel boot messages.
Also fix a few other details:
- clarify a comment about firmware speculation control
- s/KPTI/PTI
- remove various line-breaks that made the code uglier
Acked-by: David Woodhouse <dwmw@amazon.co.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We either clear the CPU_BASED_USE_MSR_BITMAPS and end up intercepting all
MSR accesses or create a valid L02 MSR bitmap and use that. This decision
has to be made every time we evaluate whether we are going to generate the
L02 MSR bitmap.
Before commit:
d28b387fb7 ("KVM/VMX: Allow direct access to MSR_IA32_SPEC_CTRL")
... this was probably OK since the decision was always identical.
This is no longer the case now since the MSR bitmap might actually
change once we decide to not intercept SPEC_CTRL and PRED_CMD.
Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: arjan.van.de.ven@intel.com
Cc: dave.hansen@intel.com
Cc: jmattson@google.com
Cc: kvm@vger.kernel.org
Cc: sironi@amazon.de
Link: http://lkml.kernel.org/r/1518305967-31356-6-git-send-email-dwmw@amazon.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
These two variables should check whether SPEC_CTRL and PRED_CMD are
supposed to be passed through to L2 guests or not. While
msr_write_intercepted_l01 would return 'true' if it is not passed through.
So just invert the result of msr_write_intercepted_l01 to implement the
correct semantics.
Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Jim Mattson <jmattson@google.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: arjan.van.de.ven@intel.com
Cc: dave.hansen@intel.com
Cc: kvm@vger.kernel.org
Cc: sironi@amazon.de
Fixes: 086e7d4118cc ("KVM: VMX: Allow direct access to MSR_IA32_SPEC_CTRL")
Link: http://lkml.kernel.org/r/1518305967-31356-5-git-send-email-dwmw@amazon.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
With retpoline, tight loops of "call this function for every XXX" are
very much pessimised by taking a prediction miss *every* time. This one
is by far the biggest contributor to the guest launch time with retpoline.
By marking the iterator slot_handle_…() functions always_inline, we can
ensure that the indirect function call can be optimised away into a
direct call and it actually generates slightly smaller code because
some of the other conditionals can get optimised away too.
Performance is now pretty close to what we see with nospectre_v2 on
the command line.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Tested-by: Filippo Sironi <sironi@amazon.de>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Filippo Sironi <sironi@amazon.de>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: arjan.van.de.ven@intel.com
Cc: dave.hansen@intel.com
Cc: jmattson@google.com
Cc: karahmed@amazon.de
Cc: kvm@vger.kernel.org
Cc: rkrcmar@redhat.com
Link: http://lkml.kernel.org/r/1518305967-31356-4-git-send-email-dwmw@amazon.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This reverts commit 64e16720ea.
We cannot call C functions like that, without marking all the
call-clobbered registers as, well, clobbered. We might have got away
with it for now because the __ibp_barrier() function was *fairly*
unlikely to actually use any other registers. But no. Just no.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: arjan.van.de.ven@intel.com
Cc: dave.hansen@intel.com
Cc: jmattson@google.com
Cc: karahmed@amazon.de
Cc: kvm@vger.kernel.org
Cc: pbonzini@redhat.com
Cc: rkrcmar@redhat.com
Cc: sironi@amazon.de
Link: http://lkml.kernel.org/r/1518305967-31356-3-git-send-email-dwmw@amazon.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Arjan points out that the Intel document only clears the 0xc2 microcode
on *some* parts with CPUID 506E3 (INTEL_FAM6_SKYLAKE_DESKTOP stepping 3).
For the Skylake H/S platform it's OK but for Skylake E3 which has the
same CPUID it isn't (yet) cleared.
So removing it from the blacklist was premature. Put it back for now.
Also, Arjan assures me that the 0x84 microcode for Kaby Lake which was
featured in one of the early revisions of the Intel document was never
released to the public, and won't be until/unless it is also validated
as safe. So those can change to 0x80 which is what all *other* versions
of the doc have identified.
Once the retrospective testing of existing public microcodes is done, we
should be back into a mode where new microcodes are only released in
batches and we shouldn't even need to update the blacklist for those
anyway, so this tweaking of the list isn't expected to be a thing which
keeps happening.
Requested-by: Arjan van de Ven <arjan.van.de.ven@intel.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: arjan.van.de.ven@intel.com
Cc: dave.hansen@intel.com
Cc: kvm@vger.kernel.org
Cc: pbonzini@redhat.com
Link: http://lkml.kernel.org/r/1518449255-2182-1-git-send-email-dwmw@amazon.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull crypto fixes from Herbert Xu:
"This fixes the following issues:
- oversize stack frames on mn10300 in sha3-generic
- warning on old compilers in sha3-generic
- API error in sun4i_ss_prng
- potential dead-lock in sun4i_ss_prng
- null-pointer dereference in sha512-mb
- endless loop when DECO acquire fails in caam
- kernel oops when hashing empty message in talitos"
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: sun4i_ss_prng - convert lock to _bh in sun4i_ss_prng_generate
crypto: sun4i_ss_prng - fix return value of sun4i_ss_prng_generate
crypto: caam - fix endless loop when DECO acquire fails
crypto: sha3-generic - Use __optimize to support old compilers
compiler-gcc.h: __nostackprotector needs gcc-4.4 and up
compiler-gcc.h: Introduce __optimize function attribute
crypto: sha3-generic - deal with oversize stack frames
crypto: talitos - fix Kernel Oops on hashing an empty file
crypto: sha512-mb - initialize pending lengths correctly
except, again, POLLFREE and POLL_BUSY_LOOP.
With this, we finally get to the promised end result:
- POLL{IN,OUT,...} are plain integers and *not* in __poll_t, so any
stray instances of ->poll() still using those will be caught by
sparse.
- eventpoll.c and select.c warning-free wrt __poll_t
- no more kernel-side definitions of POLL... - userland ones are
visible through the entire kernel (and used pretty much only for
mangle/demangle)
- same behavior as after the first series (i.e. sparc et.al. epoll(2)
working correctly).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
David Woodhouse