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21070 commits

Author SHA1 Message Date
Li, Aubrey
7486341a98 x86/platform, acpi: Bypass legacy PIC and PIT in ACPI hardware reduced mode
On a platform in ACPI Hardware-reduced mode, the legacy PIC and
PIT may not be initialized even though they may be present in
silicon. Touching these legacy components causes unexpected
results on the system.

On the Bay Trail-T(ASUS-T100) platform, touching these legacy
components blocks platform hardware low idle power state(S0ix)
during system suspend. So we should bypass them in ACPI hardware
reduced mode.

Suggested-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Li Aubrey <aubrey.li@linux.intel.com>
Cc: <alan@linux.intel.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Link: http://lkml.kernel.org/r/54FFF81C.20703@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-12 12:07:13 +01:00
Paolo Bonzini
dc9be0fac7 kvm: move advertising of KVM_CAP_IRQFD to common code
POWER supports irqfds but forgot to advertise them.  Some userspace does
not check for the capability, but others check it---thus they work on
x86 and s390 but not POWER.

To avoid that other architectures in the future make the same mistake, let
common code handle KVM_CAP_IRQFD the same way as KVM_CAP_IRQFD_RESAMPLE.

Reported-and-tested-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Fixes: 297e21053a
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2015-03-10 21:18:59 -03:00
Denys Vlasenko
263042e463 x86/asm/entry/64: Save user RSP in pt_regs->sp on SYSCALL64 fastpath
Prepare for the removal of 'usersp', by simplifying PER_CPU(old_rsp) usage:

  - use it only as temp storage

  - store the userspace stack pointer immediately in pt_regs->sp
    on syscall entry, instead of using it later, on syscall exit.

  - change C code to use pt_regs->sp only, instead of PER_CPU(old_rsp)
    and task->thread.usersp.

FIXUP/RESTORE_TOP_OF_STACK are simplified as well.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1425926364-9526-4-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-10 13:56:10 +01:00
Denys Vlasenko
616ab249f1 x86/asm/entry/64: Remove stub_iopl
stub_iopl is no longer needed: pt_regs->flags needs no fixing up
after previous change. Remove it.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1425984307-2143-1-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-10 13:56:10 +01:00
Denys Vlasenko
29722cd4ef x86/asm/entry/64: Save R11 into pt_regs->flags on SYSCALL64 fastpath
Before this patch, R11 was saved in pt_regs->r11.

Which looks natural, but requires messy shuffling to/from iret
frame whenever ptrace or e.g. sys_iopl() wants to modify flags -
because that's how this register is used by SYSCALL/SYSRET.

This patch saves R11 in pt_regs->flags, and uses that value for
the SYSRET64 instruction. Shuffling is eliminated.

FIXUP/RESTORE_TOP_OF_STACK are simplified.

stub_iopl is no longer needed: pt_regs->flags needs no fixing up.

Testing shows that syscall fast path is ~54.3 ns before
and after the patch (on 2.7 GHz Sandy Bridge CPU).

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1425926364-9526-2-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-10 13:56:10 +01:00
Andy Lutomirski
394838c960 x86/asm/entry/32: Fix user_mode() misuses
The one in do_debug() is probably harmless, but better safe than sorry.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: <stable@vger.kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/d67deaa9df5458363623001f252d1aee3215d014.1425948056.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-10 04:21:51 +01:00
Denys Vlasenko
3e1aa7cb59 x86/asm: Optimize unnecessarily wide TEST instructions
By the nature of the TEST operation, it is often possible to test
a narrower part of the operand:

    "testl $3,  mem"  ->  "testb $3, mem",
    "testq $3, %rcx"  ->  "testb $3, %cl"

This results in shorter instructions, because the TEST instruction
has no sign-entending byte-immediate forms unlike other ALU ops.

Note that this change does not create any LCP (Length-Changing Prefix)
stalls, which happen when adding a 0x66 prefix, which happens when
16-bit immediates are used, which changes such TEST instructions:

  [test_opcode] [modrm] [imm32]

to:

  [0x66] [test_opcode] [modrm] [imm16]

where [imm16] has a *different length* now: 2 bytes instead of 4.
This confuses the decoder and slows down execution.

REX prefixes were carefully designed to almost never hit this case:
adding REX prefix does not change instruction length except MOVABS
and MOV [addr],RAX instruction.

This patch does not add instructions which would use a 0x66 prefix,
code changes in assembly are:

    -48 f7 07 01 00 00 00 	testq  $0x1,(%rdi)
    +f6 07 01             	testb  $0x1,(%rdi)
    -48 f7 c1 01 00 00 00 	test   $0x1,%rcx
    +f6 c1 01             	test   $0x1,%cl
    -48 f7 c1 02 00 00 00 	test   $0x2,%rcx
    +f6 c1 02             	test   $0x2,%cl
    -41 f7 c2 01 00 00 00 	test   $0x1,%r10d
    +41 f6 c2 01          	test   $0x1,%r10b
    -48 f7 c1 04 00 00 00 	test   $0x4,%rcx
    +f6 c1 04             	test   $0x4,%cl
    -48 f7 c1 08 00 00 00 	test   $0x8,%rcx
    +f6 c1 08             	test   $0x8,%cl

Linus further notes:

   "There are no stalls from using 8-bit instruction forms.

    Now, changing from 64-bit or 32-bit 'test' instructions to 8-bit ones
    *could* cause problems if it ends up having forwarding issues, so that
    instead of just forwarding the result, you end up having to wait for
    it to be stable in the L1 cache (or possibly the register file). The
    forwarding from the store buffer is simplest and most reliable if the
    read is done at the exact same address and the exact same size as the
    write that gets forwarded.

    But that's true only if:

     (a) the write was very recent and is still in the write queue. I'm
         not sure that's the case here anyway.

     (b) on at least most Intel microarchitectures, you have to test a
         different byte than the lowest one (so forwarding a 64-bit write
         to a 8-bit read ends up working fine, as long as the 8-bit read
         is of the low 8 bits of the written data).

    A very similar issue *might* show up for registers too, not just
    memory writes, if you use 'testb' with a high-byte register (where
    instead of forwarding the value from the original producer it needs to
    go through the register file and then shifted). But it's mainly a
    problem for store buffers.

    But afaik, the way Denys changed the test instructions, neither of the
    above issues should be true.

    The real problem for store buffer forwarding tends to be "write 8
    bits, read 32 bits". That can be really surprisingly expensive,
    because the read ends up having to wait until the write has hit the
    cacheline, and we might talk tens of cycles of latency here. But
    "write 32 bits, read the low 8 bits" *should* be fast on pretty much
    all x86 chips, afaik."

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1425675332-31576-1-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-07 11:12:43 +01:00
Andy Lutomirski
a7fcf28d43 x86/asm/entry: Replace this_cpu_sp0() with current_top_of_stack() and fix it on x86_32
I broke 32-bit kernels.  The implementation of sp0 was correct
as far as I can tell, but sp0 was much weirder on x86_32 than I
realized.  It has the following issues:

 - Init's sp0 is inconsistent with everything else's: non-init tasks
   are offset by 8 bytes.  (I have no idea why, and the comment is unhelpful.)

 - vm86 does crazy things to sp0.

Fix it up by replacing this_cpu_sp0() with
current_top_of_stack() and using a new percpu variable to track
the top of the stack on x86_32.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 75182b1632 ("x86/asm/entry: Switch all C consumers of kernel_stack to this_cpu_sp0()")
Link: http://lkml.kernel.org/r/d09dbe270883433776e0cbee3c7079433349e96d.1425692936.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-07 09:34:03 +01:00
Andy Lutomirski
b27559a433 x86/asm/entry: Delay loading sp0 slightly on task switch
The change:

  75182b1632 ("x86/asm/entry: Switch all C consumers of kernel_stack to this_cpu_sp0()")

had the unintended side effect of changing the return value of
current_thread_info() during part of the context switch process.
Change it back.

This has no effect as far as I can tell -- it's just for
consistency.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/9fcaa47dd8487db59eed7a3911b6ae409476763e.1425692936.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-07 09:34:03 +01:00
Linus Torvalds
39ed853a24 Power management and ACPI fixes for v4.0-rc3
- Fix ACPI resources management problems introduced by the recent
    rework of the code in question (Jiang Liu) and a build issue
    introduced by those changes (Joachim Nilsson).
 
  - Fix a recent suspend-to-idle regression on systems where entering
    idle states causes local timers to stop, prevent suspend-to-idle
    from crashing in restricted configurations (no cpuidle driver,
    cpuidle disabled etc.) and clean up the idle loop somewhat while
    at it (Rafael J Wysocki).
 
  - Fix build problem in the cpufreq ppc driver (Geert Uytterhoeven).
 
  - Allow the ACPI backlight driver module to be loaded if ACPI is
    disabled which helps the i915 driver in those configurations
    (stable-candidate) and change the code to help debug unusual use
    cases (Chris Wilson).
 
  - Wakeup IRQ management changes in v3.18 caused some drivers on the
    at91 platform to trigger a warning from the IRQ core related to
    an unexpected combination of interrupt action handler flags.
    However, on at91 a timer IRQ is shared with some other devices
    (including system wakeup ones) and that leads to the unusual
    combination of flags in question.  To make it possible to avoid
    the warning introduce a new interrupt action handler flag (which
    can be used by drivers to indicate the special case to the core)
    and rework the problematic at91 drivers to use it and work as
    expected during system suspend/resume.  From Boris Brezillon,
    Rafael J Wysocki and Mark Rutland.
 
  - Clean up the generic power domains subsystem's debugfs interface
    (Kevin Hilman).
 
 /
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Merge tag 'pm+acpi-4.0-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management and ACPI fixes from Rafael Wysocki:
 "These are fixes for recent regressions (ACPI resources management,
  suspend-to-idle), stable-candidate fixes (ACPI backlight), fixes
  related to the wakeup IRQ management changes made in v3.18, other
  fixes (suspend-to-idle, cpufreq ppc driver) and a couple of cleanups
  (suspend-to-idle, generic power domains, ACPI backlight).

  Specifics:

   - Fix ACPI resources management problems introduced by the recent
     rework of the code in question (Jiang Liu) and a build issue
     introduced by those changes (Joachim Nilsson).

   - Fix a recent suspend-to-idle regression on systems where entering
     idle states causes local timers to stop, prevent suspend-to-idle
     from crashing in restricted configurations (no cpuidle driver,
     cpuidle disabled etc.) and clean up the idle loop somewhat while at
     it (Rafael J Wysocki).

   - Fix build problem in the cpufreq ppc driver (Geert Uytterhoeven).

   - Allow the ACPI backlight driver module to be loaded if ACPI is
     disabled which helps the i915 driver in those configurations
     (stable-candidate) and change the code to help debug unusual use
     cases (Chris Wilson).

   - Wakeup IRQ management changes in v3.18 caused some drivers on the
     at91 platform to trigger a warning from the IRQ core related to an
     unexpected combination of interrupt action handler flags.  However,
     on at91 a timer IRQ is shared with some other devices (including
     system wakeup ones) and that leads to the unusual combination of
     flags in question.

     To make it possible to avoid the warning introduce a new interrupt
     action handler flag (which can be used by drivers to indicate the
     special case to the core) and rework the problematic at91 drivers
     to use it and work as expected during system suspend/resume.  From
     Boris Brezillon, Rafael J Wysocki and Mark Rutland.

   - Clean up the generic power domains subsystem's debugfs interface
     (Kevin Hilman)"

* tag 'pm+acpi-4.0-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  genirq / PM: describe IRQF_COND_SUSPEND
  tty: serial: atmel: rework interrupt and wakeup handling
  watchdog: at91sam9: request the irq with IRQF_NO_SUSPEND
  cpuidle / sleep: Use broadcast timer for states that stop local timer
  clk: at91: implement suspend/resume for the PMC irqchip
  rtc: at91rm9200: rework wakeup and interrupt handling
  rtc: at91sam9: rework wakeup and interrupt handling
  PM / wakeup: export pm_system_wakeup symbol
  genirq / PM: Add flag for shared NO_SUSPEND interrupt lines
  ACPI / video: Propagate the error code for acpi_video_register
  ACPI / video: Load the module even if ACPI is disabled
  PM / Domains: cleanup: rename gpd -> genpd in debugfs interface
  cpufreq: ppc: Add missing #include <asm/smp.h>
  x86/PCI/ACPI: Relax ACPI resource descriptor checks to work around BIOS bugs
  x86/PCI/ACPI: Ignore resources consumed by host bridge itself
  cpuidle: Clean up fallback handling in cpuidle_idle_call()
  cpuidle / sleep: Do sanity checks in cpuidle_enter_freeze() too
  idle / sleep: Avoid excessive disabling and enabling interrupts
  PCI: versatile: Update for list_for_each_entry() API change
  genirq / PM: better describe IRQF_NO_SUSPEND semantics
2015-03-06 10:36:09 -08:00
Jiri Slaby
e893286918 x86/vdso: Fix the build on GCC5
On gcc5 the kernel does not link:

  ld: .eh_frame_hdr table[4] FDE at 0000000000000648 overlaps table[5] FDE at 0000000000000670.

Because prior GCC versions always emitted NOPs on ALIGN directives, but
gcc5 started omitting them.

.LSTARTFDEDLSI1 says:

        /* HACK: The dwarf2 unwind routines will subtract 1 from the
           return address to get an address in the middle of the
           presumed call instruction.  Since we didn't get here via
           a call, we need to include the nop before the real start
           to make up for it.  */
        .long .LSTART_sigreturn-1-.     /* PC-relative start address */

But commit 69d0627a7f ("x86 vDSO: reorder vdso32 code") from 2.6.25
replaced .org __kernel_vsyscall+32,0x90 by ALIGN right before
__kernel_sigreturn.

Of course, ALIGN need not generate any NOP in there. Esp. gcc5 collapses
vclock_gettime.o and int80.o together with no generated NOPs as "ALIGN".

So fix this by adding to that point at least a single NOP and make the
function ALIGN possibly with more NOPs then.

Kudos for reporting and diagnosing should go to Richard.

Reported-by: Richard Biener <rguenther@suse.de>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: <stable@vger.kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1425543211-12542-1-git-send-email-jslaby@suse.cz
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-06 09:34:45 +01:00
Andy Lutomirski
9b47668843 x86/asm/entry: Rename 'INIT_TSS_IST' to 'CPU_TSS_IST'
This has nothing to do with the init thread or the initial
anything. It's just the CPU's TSS.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/a0bd5e26b32a2e1f08ff99017d0997118fbb2485.1425611534.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-06 08:32:58 +01:00
Andy Lutomirski
d0a0de21f8 x86/asm/entry: Remove INIT_TSS and fold the definitions into 'cpu_tss'
The INIT_TSS is unnecessary.  Just define the initial TSS where
'cpu_tss' is defined.

While we're at it, merge the 32-bit and 64-bit definitions.  The
only syntactic change is that 32-bit kernels were computing sp0
as long, but now they compute it as unsigned long.

Verified by objdump: the contents and relocations of
.data..percpu..shared_aligned are unchanged on 32-bit and 64-bit
kernels.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/8fc39fa3f6c5d635e93afbdd1a0fe0678a6d7913.1425611534.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-06 08:32:58 +01:00
Andy Lutomirski
24933b82c0 x86/asm/entry: Rename 'init_tss' to 'cpu_tss'
It has nothing to do with init -- there's only one TSS per cpu.

Other names considered include:

 - current_tss: Confusing because we never switch the tss.
 - singleton_tss: Too long.

This patch was generated with 's/init_tss/cpu_tss/g'.  Followup
patches will fix INIT_TSS and INIT_TSS_IST by hand.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/da29fb2a793e4f649d93ce2d1ed320ebe8516262.1425611534.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-06 08:32:58 +01:00
Andy Lutomirski
9d0c914c60 x86/asm/entry/64/compat: Change the 32-bit sysenter code to use sp0
The ia32 sysenter code loaded the top of the kernel stack into
rsp by loading kernel_stack and then adjusting it.  It can be
simplified to just read sp0 directly.

This requires the addition of a new asm-offsets entry for sp0.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/88ff9006163d296a0665338585c36d9bfb85235d.1425611534.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-06 08:32:58 +01:00
Andy Lutomirski
75182b1632 x86/asm/entry: Switch all C consumers of kernel_stack to this_cpu_sp0()
This will make modifying the semantics of kernel_stack easier.

The change to ist_begin_non_atomic() is necessary because sp0 no
longer points to the same THREAD_SIZE-aligned region as RSP;
it's one byte too high for that.  At Denys' suggestion, rather
than offsetting it, just check explicitly that we're in the
correct range ending at sp0.  This has the added benefit that we
no longer assume that the thread stack is aligned to
THREAD_SIZE.

Suggested-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/ef8254ad414cbb8034c9a56396eeb24f5dd5b0de.1425611534.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-06 08:32:57 +01:00
Andy Lutomirski
8ef46a672a x86/asm/entry: Add this_cpu_sp0() to read sp0 for the current cpu
We currently store references to the top of the kernel stack in
multiple places: kernel_stack (with an offset) and
init_tss.x86_tss.sp0 (no offset).  The latter is defined by
hardware and is a clean canonical way to find the top of the
stack.  Add an accessor so we can start using it.

This needs minor paravirt tweaks.  On native, sp0 defines the
top of the kernel stack and is therefore always correct.  On Xen
and lguest, the hypervisor tracks the top of the stack, but we
want to start reading sp0 in the kernel.  Fixing this is simple:
just update our local copy of sp0 as well as the hypervisor's
copy on task switches.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/8d675581859712bee09a055ed8f785d80dac1eca.1425611534.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-06 08:32:57 +01:00
Rafael J. Wysocki
8204680c7b Merge branch 'acpi-resources'
* acpi-resources:
  x86/PCI/ACPI: Relax ACPI resource descriptor checks to work around BIOS bugs
  x86/PCI/ACPI: Ignore resources consumed by host bridge itself
  PCI: versatile: Update for list_for_each_entry() API change
2015-03-05 23:14:40 +01:00
Linus Torvalds
99aedde086 Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
 "Misc fixes: EFI fixes, an Intel Quark fix, an asm fix and an FPU
  handling fix"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/fpu/xsaves: Fix improper uses of __ex_table
  x86/intel/quark: Select COMMON_CLK
  x86/asm/entry/64: Remove a bogus 'ret_from_fork' optimization
  firmware: dmi_scan: Fix dmi_len type
  efi/libstub: Fix boundary checking in efi_high_alloc()
  firmware: dmi_scan: Fix dmi scan to handle "End of Table" structure
2015-03-05 11:25:23 -08:00
Quentin Casasnovas
06c8173eb9 x86/fpu/xsaves: Fix improper uses of __ex_table
Commit:

  f31a9f7c71 ("x86/xsaves: Use xsaves/xrstors to save and restore xsave area")

introduced alternative instructions for XSAVES/XRSTORS and commit:

  adb9d526e9 ("x86/xsaves: Add xsaves and xrstors support for booting time")

added support for the XSAVES/XRSTORS instructions at boot time.

Unfortunately both failed to properly protect them against faulting:

The 'xstate_fault' macro will use the closest label named '1'
backward and that ends up in the .altinstr_replacement section
rather than in .text. This means that the kernel will never find
in the __ex_table the .text address where this instruction might
fault, leading to serious problems if userspace manages to
trigger the fault.

Signed-off-by: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Signed-off-by: Jamie Iles <jamie.iles@oracle.com>
[ Improved the changelog, fixed some whitespace noise. ]
Acked-by: Borislav Petkov <bp@alien8.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: <stable@vger.kernel.org>
Cc: Allan Xavier <mr.a.xavier@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: adb9d526e9 ("x86/xsaves: Add xsaves and xrstors support for booting time")
Fixes: f31a9f7c71 ("x86/xsaves: Use xsaves/xrstors to save and restore xsave area")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-05 18:20:36 +01:00
Andy Shevchenko
9ab6eb51ef x86/intel/quark: Select COMMON_CLK
The commit 8bbc2a135b ("x86/intel/quark: Add Intel Quark
platform support") introduced a minimal support of Intel Quark
SoC. That allows to use core parts of the SoC. However, the SPI,
I2C, and GPIO drivers can't be selected by kernel configuration
because they depend on COMMON_CLK. The patch adds a COMMON_CLK
selection to the platfrom definition to allow user choose the drivers.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Ong, Boon Leong <boon.leong.ong@intel.com>
Cc: Bryan O'Donoghue <pure.logic@nexus-software.ie>
Cc: Darren Hart <dvhart@linux.intel.com>
Fixes: 8bbc2a135b ("x86/intel/quark: Add Intel Quark platform support")
Link: http://lkml.kernel.org/r/1425569044-2867-1-git-send-email-andriy.shevchenko@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-05 17:44:53 +01:00
Andy Lutomirski
956421fbb7 x86/asm/entry/64: Remove a bogus 'ret_from_fork' optimization
'ret_from_fork' checks TIF_IA32 to determine whether 'pt_regs' and
the related state make sense for 'ret_from_sys_call'.  This is
entirely the wrong check.  TS_COMPAT would make a little more
sense, but there's really no point in keeping this optimization
at all.

This fixes a return to the wrong user CS if we came from int
0x80 in a 64-bit task.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/4710be56d76ef994ddf59087aad98c000fbab9a4.1424989793.git.luto@amacapital.net
[ Backported from tip:x86/asm. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-05 01:12:23 +01:00
Wang Nan
5eca7453d6 x86/traps: Separate set_intr_gate() and clean up early_trap_init()
As early_trap_init() doesn't use IST, replace
set_intr_gate_ist() and set_system_intr_gate_ist() with their
standard counterparts.

set_intr_gate() requires a trace_debug symbol which we don't
have and won't use. This patch separates set_intr_gate() into two
parts, and uses base version in early_trap_init().

Reported-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: <dave.hansen@linux.intel.com>
Cc: <lizefan@huawei.com>
Cc: <masami.hiramatsu.pt@hitachi.com>
Cc: <oleg@redhat.com>
Cc: <rostedt@goodmis.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1425010789-13714-1-git-send-email-wangnan0@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-05 00:47:29 +01:00
Andy Lutomirski
1e3fbb8a1d x86/asm/entry/64: Remove a bogus 'ret_from_fork' optimization
'ret_from_fork' checks TIF_IA32 to determine whether 'pt_regs' and
the related state make sense for 'ret_from_sys_call'.  This is
entirely the wrong check.  TS_COMPAT would make a little more
sense, but there's really no point in keeping this optimization
at all.

This fixes a return to the wrong user CS if we came from int
0x80 in a 64-bit task.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/4710be56d76ef994ddf59087aad98c000fbab9a4.1424989793.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-04 22:50:53 +01:00
Denys Vlasenko
d441c1f2b7 x86/asm/entry/64: Simplify optimistic SYSRET
Avoid redundant load of %r11 (it is already loaded a few
instructions before).

Also simplify %rsp restoration, instead of two steps:

         add $0x80, %rsp
         mov 0x18(%rsp), %rsp

we can do a simplified single step to restore user-space RSP:

         mov 0x98(%rsp), %rsp

and get the same result.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
[ Clarified the changelog. ]
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1aef69b346a6db0d99cdfb0f5ba83e8c985e27d7.1424989793.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-04 22:50:52 +01:00
Denys Vlasenko
b3ab90b333 x86/asm/entry/64/compat: Use more readable constant
The last instance of "mysterious" SS+8 constant is replaced by
SIZEOF_PTREGS.

Message-Id: <1424822419-10267-1-git-send-email-dvlasenk@redhat.com>
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/d35aeba3059407ac54f472ddcfbea767ff8916ac.1424989793.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-04 22:50:52 +01:00
Denys Vlasenko
911d2bb5cc x86/asm/entry/64: Use more readable constants
Constants such as SS+8 or SS+8-RIP are mysterious.
In most cases, SS+8 is just meant to be SIZEOF_PTREGS,
SS+8-RIP is RIP's offset in the iret frame.

This patch changes some of these constants to be less
mysterious.

No code changes (verified with objdump).

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1d20491384773bd606e23a382fac23ddb49b5178.1424989793.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-04 22:50:52 +01:00
Denys Vlasenko
14f6e9532d x86/asm/entry/64/compat: Fold the IA32_ARG_FIXUP macro into its callers
Use of a small macro - one with conditional expansion - does
more harm than good. It obfuscates code, with minimal code
reuse.

For example, because of obfuscation it's not obvious that
in 'ia32_sysenter_target', we can optimize loading of r9 -
currently it is loaded with a detour through ebp.

This patch folds the IA32_ARG_FIXUP macro into its callers.

No code changes.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/4da092094cd78734384ac31e0d4ec1d8f69145a2.1424989793.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-04 22:50:52 +01:00
Denys Vlasenko
ebfc453e27 x86/asm/entry/64: Clean up and document various entry code details
This patch does a lot of cleanup in comments and formatting,
but it does not change any code:

 - Rename 'save_paranoid' to 'paranoid_entry': this makes naming
   similar to its "non-paranoid" sibling, 'error_entry',
   and to its counterpart, 'paranoid_exit'.

 - Use the same CFI annotation atop 'paranoid_entry' and 'error_entry'.

 - Fix irregular indentation of assembler operands.

 - Add/fix comments on top of 'paranoid_entry' and 'error_entry'.

 - Remove stale comment about "oldrax".

 - Make comments about "no swapgs" flag in ebx more prominent.

 - Deindent wrongly indented top-level comment atop 'paranoid_exit'.

 - Indent wrongly deindented comment inside 'error_entry'.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/4640f9fcd5ea46eb299b1cd6d3f5da3167d2f78d.1424989793.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-04 22:50:51 +01:00
Denys Vlasenko
1eeb207f87 x86/asm/entry/64: Move 'save_paranoid' and 'ret_from_fork' closer to their users
For some odd reason, these two functions are at the very top of
the file. "save_paranoid"'s caller is approximately in the middle
of it, move it there. Move 'ret_from_fork' to be right after
fork/exec helpers.

This is a pure block move, nothing is changed in the function
bodies.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/6446bbfe4094532623a5b83779b7015fec167a9d.1424989793.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-04 22:50:51 +01:00
Denys Vlasenko
b87cf63e2a x86/asm/entry: Add comments about various syscall instructions
SYSCALL/SYSRET and SYSENTER/SYSEXIT have weird semantics.
Moreover, they differ in 32- and 64-bit mode.

What is saved? What is not? Is rsp set? Are interrupts disabled?
People tend to not remember these details well enough.

This patch adds comments which explain in detail
what registers are modified by each of these instructions.

The comments are placed immediately before corresponding
entry and exit points.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/a94b98b63527797c871a81402ff5060b18fa880a.1424989793.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-04 22:50:51 +01:00
Andy Lutomirski
050273d19b x86/asm/entry/64: Remove 'int_check_syscall_exit_work'
Nothing references it anymore.

Reported-by: Denys Vlasenko <vda.linux@googlemail.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 96b6352c12 ("x86_64, entry: Remove the syscall exit audit and schedule optimizations")
Link: http://lkml.kernel.org/r/dd2a4d26ecc7a5db61b476727175cd99ae2b32a4.1424989793.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-04 22:50:50 +01:00
Denys Vlasenko
f2db9382c1 x86/asm/entry: Do mass removal of 'ARGOFFSET'
ARGOFFSET is zero now, removing it changes no code.

A few macros lost "offset" parameter, since it is always zero
now too.

No code changes - verified with objdump.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/8689f937622d9d2db0ab8be82331fa15e4ed4713.1424989793.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-04 22:50:50 +01:00
Denys Vlasenko
0d55083698 x86/asm/entry/64: Shrink code in 'paranoid_exit'
RESTORE_EXTRA_REGS + RESTORE_C_REGS looks small, but it's
a lot of instructions (fourteen). Let's reuse them.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
[ Cleaned up the labels. ]
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1421272101-16847-2-git-send-email-dvlasenk@redhat.com
Link: http://lkml.kernel.org/r/59d71848cee3ec9eb48c0252e602efd6bd560e3c.1424989793.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-04 22:50:50 +01:00
Denys Vlasenko
e90e147cbc x86/asm/entry/64: Fix comments
- Misleading and slightly incorrect comments in "struct pt_regs" are
   fixed (four instances).

 - Fix incorrect comment atop EMPTY_FRAME macro.

 - Explain in more detail what we do with stack layout during hw interrupt.

 - Correct comments about "partial stack frame" which are no longer
   true.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1423778052-21038-3-git-send-email-dvlasenk@redhat.com
Link: http://lkml.kernel.org/r/e1f4429c491fe6ceeddb879dea2786e0f8920f9c.1424989793.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-04 22:50:49 +01:00
Denys Vlasenko
76f5df43ca x86/asm/entry/64: Always allocate a complete "struct pt_regs" on the kernel stack
The 64-bit entry code was using six stack slots less by not
saving/restoring registers which are callee-preserved according
to the C ABI, and was not allocating space for them.

Only when syscalls needed a complete "struct pt_regs" was
the complete area allocated and filled in.

As an additional twist, on interrupt entry a "slightly less
truncated pt_regs" trick is used, to make nested interrupt
stacks easier to unwind.

This proved to be a source of significant obfuscation and subtle
bugs. For example, 'stub_fork' had to pop the return address,
extend the struct, save registers, and push return address back.
Ugly. 'ia32_ptregs_common' pops return address and "returns" via
jmp insn, throwing a wrench into CPU return stack cache.

This patch changes the code to always allocate a complete
"struct pt_regs" on the kernel stack. The saving of registers
is still done lazily.

"Partial pt_regs" trick on interrupt stack is retained.

Macros which manipulate "struct pt_regs" on stack are reworked:

 - ALLOC_PT_GPREGS_ON_STACK allocates the structure.

 - SAVE_C_REGS saves to it those registers which are clobbered
   by C code.

 - SAVE_EXTRA_REGS saves to it all other registers.

 - Corresponding RESTORE_* and REMOVE_PT_GPREGS_FROM_STACK macros
   reverse it.

'ia32_ptregs_common', 'stub_fork' and friends lost their ugly dance
with the return pointer.

LOAD_ARGS32 in ia32entry.S now uses symbolic stack offsets
instead of magic numbers.

'error_entry' and 'save_paranoid' now use SAVE_C_REGS +
SAVE_EXTRA_REGS instead of having it open-coded yet again.

Patch was run-tested: 64-bit executables, 32-bit executables,
strace works.

Timing tests did not show measurable difference in 32-bit
and 64-bit syscalls.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1423778052-21038-2-git-send-email-dvlasenk@redhat.com
Link: http://lkml.kernel.org/r/b89763d354aa23e670b9bdf3a40ae320320a7c2e.1424989793.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-04 22:50:49 +01:00
Denys Vlasenko
6e1327bd2b x86/asm/entry/64: Fix incorrect symbolic constant usage: R11->ARGOFFSET
Since the last fix of this nature, a few more instances have crept
in. Fix them up. No object code changes (constants have the same
value).

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1423778052-21038-1-git-send-email-dvlasenk@redhat.com
Link: http://lkml.kernel.org/r/f5e1c4084319a42e5f14d41e2d638949ce66bc08.1424989793.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-04 22:50:49 +01:00
Denys Vlasenko
49db46a67b x86/asm: Introduce push/pop macros which generate CFI_REL_OFFSET and CFI_RESTORE
Sequences:

        pushl_cfi %reg
        CFI_REL_OFFSET reg, 0

and:

        popl_cfi %reg
        CFI_RESTORE reg

happen quite often. This patch adds macros which generate them.

No assembly changes (verified with objdump -dr vmlinux.o).

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1421017655-25561-1-git-send-email-dvlasenk@redhat.com
Link: http://lkml.kernel.org/r/2202eb90f175cf45d1b2d1c64dbb5676a8ad07ad.1424989793.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-04 22:50:49 +01:00
Denys Vlasenko
69e8544cd0 x86/asm/64: Open-code register save/restore in trace_hardirqs*() thunks
This is a preparatory patch for change in "struct pt_regs"
handling in entry_64.S.

trace_hardirqs*() thunks were (ab)using a part of the
'pt_regs' handling code, namely the SAVE_ARGS/RESTORE_ARGS
macros, to save/restore registers across C function calls.

Since SAVE_ARGS is going to be changed, open-code
register saving/restoring here.

Incidentally, this removes a bit of dead code:
one SAVE_ARGS was used just to emit a CFI annotation,
but it also generated unreachable assembly instructions.

Take a page from thunk_32.S and use push/pop instructions
instead of movq, they are far shorter:
1 or 2 bytes versus 5, and no need for instructions to adjust %rsp:

   text	   data	    bss	    dec	    hex	filename
    333	     40	      0	    373	    175	thunk_64_movq.o
    104	     40	      0	    144	     90	thunk_64_push_pop.o

[ This is ugly as sin, but we'll fix up the ugliness in the next
  patch. I see no point in reordering patches just to avoid an
  ugly intermediate state.  --Andy ]

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1420927210-19738-4-git-send-email-dvlasenk@redhat.com
Link: http://lkml.kernel.org/r/4c979ad604f0f02c5ade3b3da308b53eabd5e198.1424989793.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-04 22:50:48 +01:00
Linus Torvalds
b8e81a3b68 Merge git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fixes from Marcelo Tosatti:
 "KVM bug fixes, including a SVM interrupt injection regression fix,
  MIPS and ARM bug fixes"

* git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: MIPS: Enable after disabling interrupt
  KVM: MIPS: Fix trace event to save PC directly
  KVM: SVM: fix interrupt injection (apic->isr_count always 0)
  KVM: emulate: fix CMPXCHG8B on 32-bit hosts
  KVM: VMX: fix build without CONFIG_SMP
  arm/arm64: KVM: Add exit reaons to kvm_exit event tracing
  ARM: KVM: Fix size check in __coherent_cache_guest_page
2015-03-04 09:54:10 -08:00
Jiang Liu
63f1789ec7 x86/PCI/ACPI: Ignore resources consumed by host bridge itself
When parsing resources for PCI host bridge, we should ignore resources
consumed by host bridge itself and only report window resources available
to child PCI busses.

Fixes: 593669c2ac (x86/PCI/ACPI: Use common ACPI resource interfaces ...)
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-03-04 14:09:44 +01:00
Ingo Molnar
f8e92fb4b0 A more involved rework of the alternatives framework to be able to
pad instructions and thus make using the alternatives macros more
 straightforward and without having to figure out old and new instruction
 sizes but have the toolchain figure that out for us.
 
 Furthermore, it optimizes JMPs used so that fetch and decode can be
 relieved with smaller versions of the JMPs, where possible.
 
 Some stats:
 
 x86_64 defconfig:
 
 Alternatives sites total:               2478
 Total padding added (in Bytes):         6051
 
 The padding is currently done for:
 
 X86_FEATURE_ALWAYS
 X86_FEATURE_ERMS
 X86_FEATURE_LFENCE_RDTSC
 X86_FEATURE_MFENCE_RDTSC
 X86_FEATURE_SMAP
 
 This is with the latest version of the patchset. Of course, on each
 machine the alternatives sites actually being patched are a proper
 subset of the total number.
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Merge tag 'alternatives_padding' of git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp into x86/asm

Pull alternative instructions framework improvements from Borislav Petkov:

 "A more involved rework of the alternatives framework to be able to
  pad instructions and thus make using the alternatives macros more
  straightforward and without having to figure out old and new instruction
  sizes but have the toolchain figure that out for us.

  Furthermore, it optimizes JMPs used so that fetch and decode can be
  relieved with smaller versions of the JMPs, where possible.

  Some stats:

    x86_64 defconfig:

    Alternatives sites total:               2478
    Total padding added (in Bytes):         6051

  The padding is currently done for:

    X86_FEATURE_ALWAYS
    X86_FEATURE_ERMS
    X86_FEATURE_LFENCE_RDTSC
    X86_FEATURE_MFENCE_RDTSC
    X86_FEATURE_SMAP

  This is with the latest version of the patchset. Of course, on each
  machine the alternatives sites actually being patched are a proper
  subset of the total number."

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-04 06:36:15 +01:00
Ingo Molnar
d2c032e3dc Linux 4.0-rc2
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Merge tag 'v4.0-rc2' into x86/asm, to refresh the tree

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-04 06:35:43 +01:00
Brian Gerst
7e8e385aaf x86/compat: Remove sys32_vm86_warning
The check against lastcomm is racy, and the message it produces
isn't necessary.  vm86 support can be disabled on a 32-bit
kernel also, and doesn't have this message.  Switch to
sys_ni_syscall instead.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1425439896-8322-4-git-send-email-brgerst@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-04 06:16:21 +01:00
Brian Gerst
2aa4a71092 x86/compat: Merge native and compat 32-bit syscall tables
Combine the 32-bit syscall tables into one file.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1425439896-8322-3-git-send-email-brgerst@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-04 06:16:21 +01:00
Brian Gerst
29a5ff97fa x86/compat: Remove compat_ni_syscall()
compat_ni_syscall() does the same thing as sys_ni_syscall().

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1425439896-8322-2-git-send-email-brgerst@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-04 06:16:21 +01:00
Radim Krčmář
f563db4bdb KVM: SVM: fix interrupt injection (apic->isr_count always 0)
In commit b4eef9b36d, we started to use hwapic_isr_update() != NULL
instead of kvm_apic_vid_enabled(vcpu->kvm).  This didn't work because
SVM had it defined and "apicv" path in apic_{set,clear}_isr() does not
change apic->isr_count, because it should always be 1.  The initial
value of apic->isr_count was based on kvm_apic_vid_enabled(vcpu->kvm),
which is always 0 for SVM, so KVM could have injected interrupts when it
shouldn't.

Fix it by implicitly setting SVM's hwapic_isr_update to NULL and make the
initial isr_count depend on hwapic_isr_update() for good measure.

Fixes: b4eef9b36d ("kvm: x86: vmx: NULL out hwapic_isr_update() in case of !enable_apicv")
Reported-and-tested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2015-03-02 19:04:40 -03:00
Linus Torvalds
a38ecbbd0b Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
 "A CR4-shadow 32-bit init fix, plus two typo fixes"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Init per-cpu shadow copy of CR4 on 32-bit CPUs too
  x86/platform/intel-mid: Fix trivial printk message typo in intel_mid_arch_setup()
  x86/cpu/intel: Fix trivial typo in intel_tlb_table[]
2015-03-01 12:22:44 -08:00
Linus Torvalds
d7b48fec35 Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar:
 "Two kprobes fixes and a handful of tooling fixes"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf tools: Make sparc64 arch point to sparc
  perf symbols: Define EM_AARCH64 for older OSes
  perf top: Fix SIGBUS on sparc64
  perf tools: Fix probing for PERF_FLAG_FD_CLOEXEC flag
  perf tools: Fix pthread_attr_setaffinity_np build error
  perf tools: Define _GNU_SOURCE on pthread_attr_setaffinity_np feature check
  perf bench: Fix order of arguments to memcpy_alloc_mem
  kprobes/x86: Check for invalid ftrace location in __recover_probed_insn()
  kprobes/x86: Use 5-byte NOP when the code might be modified by ftrace
2015-03-01 11:56:13 -08:00
Steven Rostedt
5b2bdbc845 x86: Init per-cpu shadow copy of CR4 on 32-bit CPUs too
Commit:

   1e02ce4ccc ("x86: Store a per-cpu shadow copy of CR4")

added a shadow CR4 such that reads and writes that do not
modify the CR4 execute much faster than always reading the
register itself.

The change modified cpu_init() in common.c, so that the
shadow CR4 gets initialized before anything uses it.

Unfortunately, there's two cpu_init()s in common.c. There's
one for 64-bit and one for 32-bit. The commit only added
the shadow init to the 64-bit path, but the 32-bit path
needs the init too.

Link: http://lkml.kernel.org/r/20150227125208.71c36402@gandalf.local.home Fixes: 1e02ce4ccc "x86: Store a per-cpu shadow copy of CR4"
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20150227145019.2bdd4354@gandalf.local.home
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-02-28 08:04:20 +01:00