14170 Commits

Author SHA1 Message Date
Jan Kiszka
0d7c1e2218 x86/jailhouse: Avoid access of unsupported platform resources
Non-root cells do not have CMOS access, thus the warm reset cannot be
enabled. There is no RTC, thus also no wall clock. Furthermore, there
are no ISA IRQs and no PIC.

Also disable probing of i8042 devices that are typically blocked for
non-root cells. In theory, access could also be granted to a non-root
cell, provided the root cell is not using the devices. But there is no
concrete scenario in sight, and disabling probing over Jailhouse allows
to build generic kernels that keep CONFIG_SERIO enabled for use in
normal systems.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: jailhouse-dev@googlegroups.com
Link: https://lkml.kernel.org/r/39b68cc2c496501c9d95e6f40e5d76e3053c3908.1511770314.git.jan.kiszka@siemens.com
2018-01-14 21:11:56 +01:00
Jan Kiszka
e85eb632f6 x86/jailhouse: Set up timekeeping
Get the precalibrated frequencies for the TSC and the APIC timer from
the Jailhouse platform info and set the kernel values accordingly.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: jailhouse-dev@googlegroups.com
Link: https://lkml.kernel.org/r/b2557426332fc337a74d3141cb920f7dce9ad601.1511770314.git.jan.kiszka@siemens.com
2018-01-14 21:11:56 +01:00
Jan Kiszka
87e65d05bb x86/jailhouse: Enable PMTIMER
Jailhouse exposes the PMTIMER as only reference clock to all cells. Pick
up its address from the setup data. Allow to enable the Linux support of
it by relaxing its strict dependency on ACPI.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: jailhouse-dev@googlegroups.com
Link: https://lkml.kernel.org/r/6d5c3fadd801eb3fba9510e2d3db14a9c404a1a0.1511770314.git.jan.kiszka@siemens.com
2018-01-14 21:11:55 +01:00
Jan Kiszka
11c8dc419b x86/jailhouse: Enable APIC and SMP support
Register the APIC which Jailhouse always exposes at 0xfee00000 if in
xAPIC mode or via MSRs as x2APIC. The latter is only available if it was
already activated because there is no support for switching its mode
during runtime.

Jailhouse requires the APIC to be operated in phys-flat mode. Ensure
that this mode is selected by Linux.

The available CPUs are taken from the setup data structure that the
loader filled and registered with the kernel.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: jailhouse-dev@googlegroups.com
Link: https://lkml.kernel.org/r/8b2255da0a9856c530293a67aa9d6addfe102a2b.1511770314.git.jan.kiszka@siemens.com
2018-01-14 21:11:55 +01:00
Jan Kiszka
4a362601ba x86/jailhouse: Add infrastructure for running in non-root cell
The Jailhouse hypervisor is able to statically partition a multicore
system into multiple so-called cells. Linux is used as boot loader and
continues to run in the root cell after Jailhouse is enabled. Linux can
also run in non-root cells.

Jailhouse does not emulate usual x86 devices. It also provides no
complex ACPI but basic platform information that the boot loader
forwards via setup data. This adds the infrastructure to detect when
running in a non-root cell so that the platform can be configured as
required in succeeding steps.

Support is limited to x86-64 so far, primarily because no boot loader
stub exists for i386 and, thus, we wouldn't be able to test the 32-bit
path.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: jailhouse-dev@googlegroups.com
Link: https://lkml.kernel.org/r/7f823d077b38b1a70c526b40b403f85688c137d3.1511770314.git.jan.kiszka@siemens.com
2018-01-14 21:11:54 +01:00
Jan Kiszka
a09c5ec00a x86: Introduce and use MP IRQ trigger and polarity defines
MP_IRQDIR_* constants pointed in the right direction but remained unused so
far: It's cleaner to use symbolic values for the IRQ flags in the MP config
table. That also saves some comments.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: jailhouse-dev@googlegroups.com
Link: https://lkml.kernel.org/r/60809926663a1d38e2a5db47d020d6e2e7a70019.1511770314.git.jan.kiszka@siemens.com
2018-01-14 21:11:54 +01:00
Jan Kiszka
e348caef8b x86/platform: Control warm reset setup via legacy feature flag
Allow to turn off the setup of BIOS-managed warm reset via a new flag in
x86_legacy_features. Besides the UV1, the upcoming jailhose guest support
needs this switched off.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: jailhouse-dev@googlegroups.com
Link: https://lkml.kernel.org/r/44376558129d70a2c1527959811371ef4b82e829.1511770314.git.jan.kiszka@siemens.com
2018-01-14 21:11:53 +01:00
Jan Kiszka
32c9c801a8 x86/apic: Install an empty physflat_init_apic_ldr
As the comment already stated, there is no need for setting up LDR (and
DFR) in physflat mode as it remains unused (see SDM, 10.6.2.1).
flat_init_apic_ldr only served as a placeholder for a nop operation so
far, causing no harm.

That will change when running over the Jailhouse hypervisor. Here we
must not touch LDR in a way that destroys the mapping originally set up
by the Linux root cell. Jailhouse enforces this setting in order to
efficiently validate any IPI requests sent by a cell.

Avoid a needless clash caused by flat_init_apic_ldr by installing a true
nop handler.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: jailhouse-dev@googlegroups.com
Link: https://lkml.kernel.org/r/f9867d294cdae4d45ed89d3a2e6adb524f4f6794.1511770314.git.jan.kiszka@siemens.com
2018-01-14 21:11:53 +01:00
Peter Zijlstra
aa83c45762 x86/tsc: Introduce early tsc clocksource
Without TSC_KNOWN_FREQ the TSC clocksource is registered so late that the
kernel first switches to the HPET. Using HPET on large CPU count machines is
undesirable.

Therefore register a tsc-early clocksource using the preliminary tsc_khz
from quick calibration. Then when the final TSC calibration is done, it
can switch to the tuned frequency.

The only notably problem is that the real tsc clocksource must be marked
with CLOCK_SOURCE_VALID_FOR_HRES, otherwise it will not be selected when
unregistering tsc-early. tsc-early cannot be left registered, because then
the clocksource code would fall back to it when we tsc clocksource is
marked unstable later.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: len.brown@intel.com
Cc: rui.zhang@intel.com
Cc: Len Brown <lenb@kernel.org>
Link: https://lkml.kernel.org/r/20171222092243.431585460@infradead.org
2018-01-14 20:18:23 +01:00
Peter Zijlstra
6d671e1b85 x86/time: Unconditionally register legacy timer interrupt
Even without a PIC/PIT the legacy timer interrupt is required for HPET in
legacy replacement mode.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: len.brown@intel.com
Cc: rui.zhang@intel.com
Link: https://lkml.kernel.org/r/20171222092243.382623763@infradead.org
2018-01-14 20:18:23 +01:00
Peter Zijlstra
30c7e5b123 x86/tsc: Allow TSC calibration without PIT
Zhang Rui reported that a Surface Pro 4 will fail to boot with
lapic=notscdeadline. Part of the problem is that that machine doesn't have
a PIT.

If, for some reason, the TSC init has to fall back to TSC calibration, it
relies on the PIT to be present.

Allow TSC calibration to reliably fall back to HPET.

The below results in an accurate TSC measurement when forced on a IVB:

  tsc: Unable to calibrate against PIT
  tsc: No reference (HPET/PMTIMER) available
  tsc: Unable to calibrate against PIT
  tsc: using HPET reference calibration
  tsc: Detected 2792.451 MHz processor

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: len.brown@intel.com
Cc: rui.zhang@intel.com
Link: https://lkml.kernel.org/r/20171222092243.333145937@infradead.org
2018-01-14 20:18:23 +01:00
Andi Kleen
327867faa4 x86/idt: Mark IDT tables __initconst
const variables must use __initconst, not __initdata.

Fix this up for the IDT tables, which got it consistently wrong.

Fixes: 16bc18d895ce ("x86/idt: Move 32-bit idt_descr to C code")
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20171222001821.2157-7-andi@firstfloor.org
2018-01-14 20:09:45 +01:00
Linus Torvalds
40548c6b6c Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 pti updates from Thomas Gleixner:
 "This contains:

   - a PTI bugfix to avoid setting reserved CR3 bits when PCID is
     disabled. This seems to cause issues on a virtual machine at least
     and is incorrect according to the AMD manual.

   - a PTI bugfix which disables the perf BTS facility if PTI is
     enabled. The BTS AUX buffer is not globally visible and causes the
     CPU to fault when the mapping disappears on switching CR3 to user
     space. A full fix which restores BTS on PTI is non trivial and will
     be worked on.

   - PTI bugfixes for EFI and trusted boot which make sure that the user
     space visible page table entries have the NX bit cleared

   - removal of dead code in the PTI pagetable setup functions

   - add PTI documentation

   - add a selftest for vsyscall to verify that the kernel actually
     implements what it advertises.

   - a sysfs interface to expose vulnerability and mitigation
     information so there is a coherent way for users to retrieve the
     status.

   - the initial spectre_v2 mitigations, aka retpoline:

      + The necessary ASM thunk and compiler support

      + The ASM variants of retpoline and the conversion of affected ASM
        code

      + Make LFENCE serializing on AMD so it can be used as speculation
        trap

      + The RSB fill after vmexit

   - initial objtool support for retpoline

  As I said in the status mail this is the most of the set of patches
  which should go into 4.15 except two straight forward patches still on
  hold:

   - the retpoline add on of LFENCE which waits for ACKs

   - the RSB fill after context switch

  Both should be ready to go early next week and with that we'll have
  covered the major holes of spectre_v2 and go back to normality"

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (28 commits)
  x86,perf: Disable intel_bts when PTI
  security/Kconfig: Correct the Documentation reference for PTI
  x86/pti: Fix !PCID and sanitize defines
  selftests/x86: Add test_vsyscall
  x86/retpoline: Fill return stack buffer on vmexit
  x86/retpoline/irq32: Convert assembler indirect jumps
  x86/retpoline/checksum32: Convert assembler indirect jumps
  x86/retpoline/xen: Convert Xen hypercall indirect jumps
  x86/retpoline/hyperv: Convert assembler indirect jumps
  x86/retpoline/ftrace: Convert ftrace assembler indirect jumps
  x86/retpoline/entry: Convert entry assembler indirect jumps
  x86/retpoline/crypto: Convert crypto assembler indirect jumps
  x86/spectre: Add boot time option to select Spectre v2 mitigation
  x86/retpoline: Add initial retpoline support
  objtool: Allow alternatives to be ignored
  objtool: Detect jumps to retpoline thunks
  x86/pti: Make unpoison of pgd for trusted boot work for real
  x86/alternatives: Fix optimize_nops() checking
  sysfs/cpu: Fix typos in vulnerability documentation
  x86/cpu/AMD: Use LFENCE_RDTSC in preference to MFENCE_RDTSC
  ...
2018-01-14 09:51:25 -08:00
Ville Syrjälä
fc90ccfd28 Revert "x86/apic: Remove init_bsp_APIC()"
This reverts commit b371ae0d4a194b178817b0edfb6a7395c7aec37a. It causes
boot hangs on old P3/P4 systems when the local APIC is enforced in UP mode.

Reported-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Dou Liyang <douly.fnst@cn.fujitsu.com>
Cc: yinghai@kernel.org
Cc: bhe@redhat.com
Link: https://lkml.kernel.org/r/20171128145350.21560-1-ville.syrjala@linux.intel.com
2018-01-14 12:14:51 +01:00
Len Brown
4b5b212723 x86/tsc: Print tsc_khz, when it differs from cpu_khz
If CPU and TSC frequency are the same the printout of the CPU frequency is
valid for the TSC as well:

      tsc: Detected 2900.000 MHz processor

If the TSC frequency is different there is no information in dmesg. Add a
conditional printout:

  tsc: Detected 2904.000 MHz TSC

Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: peterz@infradead.org
Link: https://lkml.kernel.org/r/537b342debcd8e8aebc8d631015dcdf9f9ba8a26.1513920414.git.len.brown@intel.com
2018-01-14 12:14:50 +01:00
Len Brown
b511203093 x86/tsc: Fix erroneous TSC rate on Skylake Xeon
The INTEL_FAM6_SKYLAKE_X hardcoded crystal_khz value of 25MHZ is
problematic:

 - SKX workstations (with same model # as server variants) use a 24 MHz
   crystal.  This results in a -4.0% time drift rate on SKX workstations.

 - SKX servers subject the crystal to an EMI reduction circuit that reduces its
   actual frequency by (approximately) -0.25%.  This results in -1 second per
   10 minute time drift as compared to network time.

This issue can also trigger a timer and power problem, on configurations
that use the LAPIC timer (versus the TSC deadline timer).  Clock ticks
scheduled with the LAPIC timer arrive a few usec before the time they are
expected (according to the slow TSC).  This causes Linux to poll-idle, when
it should be in an idle power saving state.  The idle and clock code do not
graciously recover from this error, sometimes resulting in significant
polling and measurable power impact.

Stop using native_calibrate_tsc() for INTEL_FAM6_SKYLAKE_X.
native_calibrate_tsc() will return 0, boot will run with tsc_khz = cpu_khz,
and the TSC refined calibration will update tsc_khz to correct for the
difference.

[ tglx: Sanitized change log ]

Fixes: 6baf3d61821f ("x86/tsc: Add additional Intel CPU models to the crystal quirk list")
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: peterz@infradead.org
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/ff6dcea166e8ff8f2f6a03c17beab2cb436aa779.1513920414.git.len.brown@intel.com
2018-01-14 12:14:50 +01:00
Len Brown
da4ae6c4a0 x86/tsc: Future-proof native_calibrate_tsc()
If the crystal frequency cannot be determined via CPUID(15).crystal_khz or
the built-in table then native_calibrate_tsc() will still set the
X86_FEATURE_TSC_KNOWN_FREQ flag which prevents the refined TSC calibration.

As a consequence such systems use cpu_khz for the TSC frequency which is
incorrect when cpu_khz != tsc_khz resulting in time drift.

Return early when the crystal frequency cannot be retrieved without setting
the X86_FEATURE_TSC_KNOWN_FREQ flag. This ensures that the refined TSC
calibration is invoked.

[ tglx: Steam-blastered changelog. Sigh ]

Fixes: 4ca4df0b7eb0 ("x86/tsc: Mark TSC frequency determined by CPUID as known")
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: peterz@infradead.org
Cc: Bin Gao <bin.gao@intel.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/0fe2503aa7d7fc69137141fc705541a78101d2b9.1513920414.git.len.brown@intel.com
2018-01-14 12:14:50 +01:00
Eric W. Biederman
2f82a46f66 signal: Remove _sys_private and _overrun_incr from struct compat_siginfo
We have never passed either field to or from userspace so just remove them.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-01-12 14:34:46 -06:00
Andi Kleen
7614e913db x86/retpoline/irq32: Convert assembler indirect jumps
Convert all indirect jumps in 32bit irq inline asm code to use non
speculative sequences.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: Rik van Riel <riel@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: thomas.lendacky@amd.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kees Cook <keescook@google.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org>
Cc: Paul Turner <pjt@google.com>
Link: https://lkml.kernel.org/r/1515707194-20531-12-git-send-email-dwmw@amazon.co.uk
2018-01-12 00:14:32 +01:00
David Woodhouse
9351803bd8 x86/retpoline/ftrace: Convert ftrace assembler indirect jumps
Convert all indirect jumps in ftrace assembler code to use non-speculative
sequences when CONFIG_RETPOLINE is enabled.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: Rik van Riel <riel@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: thomas.lendacky@amd.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kees Cook <keescook@google.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org>
Cc: Paul Turner <pjt@google.com>
Link: https://lkml.kernel.org/r/1515707194-20531-8-git-send-email-dwmw@amazon.co.uk
2018-01-12 00:14:30 +01:00
David Woodhouse
da28512156 x86/spectre: Add boot time option to select Spectre v2 mitigation
Add a spectre_v2= option to select the mitigation used for the indirect
branch speculation vulnerability.

Currently, the only option available is retpoline, in its various forms.
This will be expanded to cover the new IBRS/IBPB microcode features.

The RETPOLINE_AMD feature relies on a serializing LFENCE for speculation
control. For AMD hardware, only set RETPOLINE_AMD if LFENCE is a
serializing instruction, which is indicated by the LFENCE_RDTSC feature.

[ tglx: Folded back the LFENCE/AMD fixes and reworked it so IBRS
  	integration becomes simple ]

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: Rik van Riel <riel@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: thomas.lendacky@amd.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kees Cook <keescook@google.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org>
Cc: Paul Turner <pjt@google.com>
Link: https://lkml.kernel.org/r/1515707194-20531-5-git-send-email-dwmw@amazon.co.uk
2018-01-12 00:14:29 +01:00
David Woodhouse
76b043848f x86/retpoline: Add initial retpoline support
Enable the use of -mindirect-branch=thunk-extern in newer GCC, and provide
the corresponding thunks. Provide assembler macros for invoking the thunks
in the same way that GCC does, from native and inline assembler.

This adds X86_FEATURE_RETPOLINE and sets it by default on all CPUs. In
some circumstances, IBRS microcode features may be used instead, and the
retpoline can be disabled.

On AMD CPUs if lfence is serialising, the retpoline can be dramatically
simplified to a simple "lfence; jmp *\reg". A future patch, after it has
been verified that lfence really is serialising in all circumstances, can
enable this by setting the X86_FEATURE_RETPOLINE_AMD feature bit in addition
to X86_FEATURE_RETPOLINE.

Do not align the retpoline in the altinstr section, because there is no
guarantee that it stays aligned when it's copied over the oldinstr during
alternative patching.

[ Andi Kleen: Rename the macros, add CONFIG_RETPOLINE option, export thunks]
[ tglx: Put actual function CALL/JMP in front of the macros, convert to
  	symbolic labels ]
[ dwmw2: Convert back to numeric labels, merge objtool fixes ]

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: Rik van Riel <riel@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: thomas.lendacky@amd.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kees Cook <keescook@google.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org>
Cc: Paul Turner <pjt@google.com>
Link: https://lkml.kernel.org/r/1515707194-20531-4-git-send-email-dwmw@amazon.co.uk
2018-01-12 00:14:28 +01:00
Dave Hansen
445b69e3b7 x86/pti: Make unpoison of pgd for trusted boot work for real
The inital fix for trusted boot and PTI potentially misses the pgd clearing
if pud_alloc() sets a PGD.  It probably works in *practice* because for two
adjacent calls to map_tboot_page() that share a PGD entry, the first will
clear NX, *then* allocate and set the PGD (without NX clear).  The second
call will *not* allocate but will clear the NX bit.

Defer the NX clearing to a point after it is known that all top-level
allocations have occurred.  Add a comment to clarify why.

[ tglx: Massaged changelog ]

Fixes: 262b6b30087 ("x86/tboot: Unbreak tboot with PTI enabled")
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: "Tim Chen" <tim.c.chen@linux.intel.com>
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: peterz@infradead.org
Cc: ning.sun@intel.com
Cc: tboot-devel@lists.sourceforge.net
Cc: andi@firstfloor.org
Cc: luto@kernel.org
Cc: law@redhat.com
Cc: pbonzini@redhat.com
Cc: torvalds@linux-foundation.org
Cc: gregkh@linux-foundation.org
Cc: dwmw@amazon.co.uk
Cc: nickc@redhat.com
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180110224939.2695CD47@viggo.jf.intel.com
2018-01-11 23:36:59 +01:00
Jiri Bohac
2a3e83c6f9 x86/gart: Exclude GART aperture from vmcore
On machines where the GART aperture is mapped over physical RAM
/proc/vmcore contains the remapped range and reading it may cause hangs or
reboots.

In the past, the GART region was added into the resource map, implemented
by commit 56dd669a138c ("[PATCH] Insert GART region into resource map")

However, inserting the iomem_resource from the early GART code caused
resource conflicts with some AGP drivers (bko#72201), which got avoided by
reverting the patch in commit 707d4eefbdb3 ("Revert [PATCH] Insert GART
region into resource map"). This revert introduced the /proc/vmcore bug.

The vmcore ELF header is either prepared by the kernel (when using the
kexec_file_load syscall) or by the kexec userspace (when using the kexec_load
syscall). Since we no longer have the GART iomem resource, the userspace
kexec has no way of knowing which region to exclude from the ELF header.

Changes from v1 of this patch:
Instead of excluding the aperture from the ELF header, this patch
makes /proc/vmcore return zeroes in the second kernel when attempting to
read the aperture region. This is done by reusing the
gart_oldmem_pfn_is_ram infrastructure originally intended to exclude XEN
balooned memory. This works for both, the kexec_file_load and kexec_load
syscalls.

[Note that the GART region is the same in the first and second kernels:
regardless whether the first kernel fixed up the northbridge/bios setting
and mapped the aperture over physical memory, the second kernel finds the
northbridge properly configured by the first kernel and the aperture
never overlaps with e820 memory because the second kernel has a fake e820
map created from the crashkernel memory regions. Thus, the second kernel
keeps the aperture address/size as configured by the first kernel.]

register_oldmem_pfn_is_ram can only register one callback and returns an error
if the callback has been registered already. Since XEN used to be the only user
of this function, it never checks the return value. Now that we have more than
one user, I added a WARN_ON just in case agp, XEN, or any other future user of
register_oldmem_pfn_is_ram were to step on each other's toes.

Fixes: 707d4eefbdb3 ("Revert [PATCH] Insert GART region into resource map")
Signed-off-by: Jiri Bohac <jbohac@suse.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Baoquan He <bhe@redhat.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: David Airlie <airlied@linux.ie>
Cc: yinghai@kernel.org
Cc: joro@8bytes.org
Cc: kexec@lists.infradead.org
Cc: Borislav Petkov <bp@alien8.de>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Link: https://lkml.kernel.org/r/20180106010013.73suskgxm7lox7g6@dwarf.suse.cz
2018-01-11 15:09:24 +01:00
Borislav Petkov
612e8e9350 x86/alternatives: Fix optimize_nops() checking
The alternatives code checks only the first byte whether it is a NOP, but
with NOPs in front of the payload and having actual instructions after it
breaks the "optimized' test.

Make sure to scan all bytes before deciding to optimize the NOPs in there.

Reported-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Andrew Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org>
Cc: Paul Turner <pjt@google.com>
Link: https://lkml.kernel.org/r/20180110112815.mgciyf5acwacphkq@pd.tnic
2018-01-10 19:36:22 +01:00
Christoph Hellwig
ea8c64ace8 dma-mapping: move swiotlb arch helpers to a new header
phys_to_dma, dma_to_phys and dma_capable are helpers published by
architecture code for use of swiotlb and xen-swiotlb only.  Drivers are
not supposed to use these directly, but use the DMA API instead.

Move these to a new asm/dma-direct.h helper, included by a
linux/dma-direct.h wrapper that provides the default linear mapping
unless the architecture wants to override it.

In the MIPS case the existing dma-coherent.h is reused for now as
untangling it will take a bit of work.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Robin Murphy <robin.murphy@arm.com>
2018-01-10 16:40:54 +01:00
Joe Perches
6cbaefb4bf treewide: Use DEVICE_ATTR_WO
Convert DEVICE_ATTR uses to DEVICE_ATTR_WO where possible.

Done with perl script:

$ git grep -w --name-only DEVICE_ATTR | \
  xargs perl -i -e 'local $/; while (<>) { s/\bDEVICE_ATTR\s*\(\s*(\w+)\s*,\s*\(?(?:\s*S_IWUSR\s*|\s*0200\s*)\)?\s*,\s*NULL\s*,\s*\s_store\s*\)/DEVICE_ATTR_WO(\1)/g; print;}'

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-09 16:34:35 +01:00
Tom Lendacky
9c6a73c758 x86/cpu/AMD: Use LFENCE_RDTSC in preference to MFENCE_RDTSC
With LFENCE now a serializing instruction, use LFENCE_RDTSC in preference
to MFENCE_RDTSC.  However, since the kernel could be running under a
hypervisor that does not support writing that MSR, read the MSR back and
verify that the bit has been set successfully.  If the MSR can be read
and the bit is set, then set the LFENCE_RDTSC feature, otherwise set the
MFENCE_RDTSC feature.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Paul Turner <pjt@google.com>
Link: https://lkml.kernel.org/r/20180108220932.12580.52458.stgit@tlendack-t1.amdoffice.net
2018-01-09 01:43:11 +01:00
Tom Lendacky
e4d0e84e49 x86/cpu/AMD: Make LFENCE a serializing instruction
To aid in speculation control, make LFENCE a serializing instruction
since it has less overhead than MFENCE.  This is done by setting bit 1
of MSR 0xc0011029 (DE_CFG).  Some families that support LFENCE do not
have this MSR.  For these families, the LFENCE instruction is already
serializing.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Paul Turner <pjt@google.com>
Link: https://lkml.kernel.org/r/20180108220921.12580.71694.stgit@tlendack-t1.amdoffice.net
2018-01-09 01:43:10 +01:00
Dave Hansen
262b6b3008 x86/tboot: Unbreak tboot with PTI enabled
This is another case similar to what EFI does: create a new set of
page tables, map some code at a low address, and jump to it.  PTI
mistakes this low address for userspace and mistakenly marks it
non-executable in an effort to make it unusable for userspace.

Undo the poison to allow execution.

Fixes: 385ce0ea4c07 ("x86/mm/pti: Add Kconfig")
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Jeff Law <law@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org>
Cc: David" <dwmw@amazon.co.uk>
Cc: Nick Clifton <nickc@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180108102805.GK25546@redhat.com
2018-01-08 17:29:18 +01:00
Thomas Gleixner
61dc0f555b x86/cpu: Implement CPU vulnerabilites sysfs functions
Implement the CPU vulnerabilty show functions for meltdown, spectre_v1 and
spectre_v2.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linuxfoundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lkml.kernel.org/r/20180107214913.177414879@linutronix.de
2018-01-08 11:10:40 +01:00
David Woodhouse
99c6fa2511 x86/cpufeatures: Add X86_BUG_SPECTRE_V[12]
Add the bug bits for spectre v1/2 and force them unconditionally for all
cpus.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: Rik van Riel <riel@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kees Cook <keescook@google.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org>
Cc: Paul Turner <pjt@google.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1515239374-23361-2-git-send-email-dwmw@amazon.co.uk
2018-01-06 21:57:19 +01:00
Jia Zhang
b94b737331 x86/microcode/intel: Extend BDW late-loading with a revision check
Instead of blacklisting all model 79 CPUs when attempting a late
microcode loading, limit that only to CPUs with microcode revisions <
0x0b000021 because only on those late loading may cause a system hang.

For such processors either:

a) a BIOS update which might contain a newer microcode revision

or

b) the early microcode loading method

should be considered.

Processors with revisions 0x0b000021 or higher will not experience such
hangs.

For more details, see erratum BDF90 in document #334165 (Intel Xeon
Processor E7-8800/4800 v4 Product Family Specification Update) from
September 2017.

[ bp: Heavily massage commit message and pr_* statements. ]

Fixes: 723f2828a98c ("x86/microcode/intel: Disable late loading on model 79")
Signed-off-by: Jia Zhang <qianyue.zj@alibaba-inc.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Tony Luck <tony.luck@intel.com>
Cc: x86-ml <x86@kernel.org>
Cc: <stable@vger.kernel.org> # v4.14
Link: http://lkml.kernel.org/r/1514772287-92959-1-git-send-email-qianyue.zj@alibaba-inc.com
2018-01-06 14:44:57 +01:00
Ingo Molnar
b6815f3545 Merge branch 'linus' into perf/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-01-06 12:07:10 +01:00
Linus Torvalds
abb7099dbc Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull  more x86 pti fixes from Thomas Gleixner:
 "Another small stash of fixes for fallout from the PTI work:

   - Fix the modules vs. KASAN breakage which was caused by making
     MODULES_END depend of the fixmap size. That was done when the cpu
     entry area moved into the fixmap, but now that we have a separate
     map space for that this is causing more issues than it solves.

   - Use the proper cache flush methods for the debugstore buffers as
     they are mapped/unmapped during runtime and not statically mapped
     at boot time like the rest of the cpu entry area.

   - Make the map layout of the cpu_entry_area consistent for 4 and 5
     level paging and fix the KASLR vaddr_end wreckage.

   - Use PER_CPU_EXPORT for per cpu variable and while at it unbreak
     nvidia gfx drivers by dropping the GPL export. The subject line of
     the commit tells it the other way around, but I noticed that too
     late.

   - Fix the ASM alternative macros so they can be used in the middle of
     an inline asm block.

   - Rename the BUG_CPU_INSECURE flag to BUG_CPU_MELTDOWN so the attack
     vector is properly identified. The Spectre mitigations will come
     with their own bug bits later"

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/pti: Rename BUG_CPU_INSECURE to BUG_CPU_MELTDOWN
  x86/alternatives: Add missing '\n' at end of ALTERNATIVE inline asm
  x86/tlb: Drop the _GPL from the cpu_tlbstate export
  x86/events/intel/ds: Use the proper cache flush method for mapping ds buffers
  x86/kaslr: Fix the vaddr_end mess
  x86/mm: Map cpu_entry_area at the same place on 4/5 level
  x86/mm: Set MODULES_END to 0xffffffffff000000
2018-01-05 12:23:57 -08:00
Linus Torvalds
b03acc4cc2 Merge branch 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull EFI updates from Thomas Gleixner:

 - A fix for a add_efi_memmap parameter regression which ensures that
   the parameter is parsed before it is used.

 - Reinstate the virtual capsule mapping as the cached copy turned out
   to break Quark and other things

 - Remove Matt Fleming as EFI co-maintainer. He stepped back a few days
   ago. Thanks Matt for all your great work!

* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  MAINTAINERS: Remove Matt Fleming as EFI co-maintainer
  efi/capsule-loader: Reinstate virtual capsule mapping
  x86/efi: Fix kernel param add_efi_memmap regression
2018-01-05 12:20:35 -08:00
Thomas Gleixner
de791821c2 x86/pti: Rename BUG_CPU_INSECURE to BUG_CPU_MELTDOWN
Use the name associated with the particular attack which needs page table
isolation for mitigation.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: David Woodhouse <dwmw@amazon.co.uk>
Cc: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Cc: Jiri Koshina <jikos@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Lutomirski  <luto@amacapital.net>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Turner <pjt@google.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Greg KH <gregkh@linux-foundation.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kees Cook <keescook@google.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1801051525300.1724@nanos
2018-01-05 15:34:43 +01:00
Sergey Senozhatsky
7b6061627e x86: do not use print_symbol()
print_symbol() is a very old API that has been obsoleted by %pS format
specifier in a normal printk() call.

Replace print_symbol() with a direct printk("%pS") call and correctly
handle continuous lines.

Link: http://lkml.kernel.org/r/20171211125025.2270-9-sergey.senozhatsky@gmail.com
To: Andrew Morton <akpm@linux-foundation.org>
To: Russell King <linux@armlinux.org.uk>
To: Catalin Marinas <catalin.marinas@arm.com>
To: Mark Salter <msalter@redhat.com>
To: Tony Luck <tony.luck@intel.com>
To: David Howells <dhowells@redhat.com>
To: Yoshinori Sato <ysato@users.sourceforge.jp>
To: Guan Xuetao <gxt@mprc.pku.edu.cn>
To: Borislav Petkov <bp@alien8.de>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Thomas Gleixner <tglx@linutronix.de>
To: Peter Zijlstra <peterz@infradead.org>
To: Vineet Gupta <vgupta@synopsys.com>
To: Fengguang Wu <fengguang.wu@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: LKML <linux-kernel@vger.kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-c6x-dev@linux-c6x.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-am33-list@redhat.com
Cc: linux-sh@vger.kernel.org
Cc: linux-edac@vger.kernel.org
Cc: x86@kernel.org
Cc: linux-snps-arc@lists.infradead.org
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Borislav Petkov <bp@suse.de> # mce.c part
[pmladek@suse.com: updated commit message]
Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-01-05 15:23:01 +01:00
Andy Shevchenko
a89bca2782 ACPI / x86: boot: Propagate error code in acpi_gsi_to_irq()
acpi_get_override_irq() followed by acpi_register_gsi() returns negative
error code on failure.

Propagate it from acpi_gsi_to_irq() to callers.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
[ rjw : Subject/changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-01-05 14:10:24 +01:00
Linus Torvalds
00a5ae218d Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 page table isolation fixes from Thomas Gleixner:
 "A couple of urgent fixes for PTI:

   - Fix a PTE mismatch between user and kernel visible mapping of the
     cpu entry area (differs vs. the GLB bit) and causes a TLB mismatch
     MCE on older AMD K8 machines

   - Fix the misplaced CR3 switch in the SYSCALL compat entry code which
     causes access to unmapped kernel memory resulting in double faults.

   - Fix the section mismatch of the cpu_tss_rw percpu storage caused by
     using a different mechanism for declaration and definition.

   - Two fixes for dumpstack which help to decode entry stack issues
     better

   - Enable PTI by default in Kconfig. We should have done that earlier,
     but it slipped through the cracks.

   - Exclude AMD from the PTI enforcement. Not necessarily a fix, but if
     AMD is so confident that they are not affected, then we should not
     burden users with the overhead"

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/process: Define cpu_tss_rw in same section as declaration
  x86/pti: Switch to kernel CR3 at early in entry_SYSCALL_compat()
  x86/dumpstack: Print registers for first stack frame
  x86/dumpstack: Fix partial register dumps
  x86/pti: Make sure the user/kernel PTEs match
  x86/cpu, x86/pti: Do not enable PTI on AMD processors
  x86/pti: Enable PTI by default
2018-01-03 16:41:07 -08:00
Nick Desaulniers
2fd9c41aea x86/process: Define cpu_tss_rw in same section as declaration
cpu_tss_rw is declared with DECLARE_PER_CPU_PAGE_ALIGNED
but then defined with DEFINE_PER_CPU_SHARED_ALIGNED
leading to section mismatch warnings.

Use DEFINE_PER_CPU_PAGE_ALIGNED consistently. This is necessary because
it's mapped to the cpu entry area and must be page aligned.

[ tglx: Massaged changelog a bit ]

Fixes: 1a935bc3d4ea ("x86/entry: Move SYSENTER_stack to the beginning of struct tss_struct")
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: thomas.lendacky@amd.com
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: tklauser@distanz.ch
Cc: minipli@googlemail.com
Cc: me@kylehuey.com
Cc: namit@vmware.com
Cc: luto@kernel.org
Cc: jpoimboe@redhat.com
Cc: tj@kernel.org
Cc: cl@linux.com
Cc: bp@suse.de
Cc: thgarnie@google.com
Cc: kirill.shutemov@linux.intel.com
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180103203954.183360-1-ndesaulniers@google.com
2018-01-03 23:19:33 +01:00
Josh Poimboeuf
3ffdeb1a02 x86/dumpstack: Print registers for first stack frame
In the stack dump code, if the frame after the starting pt_regs is also
a regs frame, the registers don't get printed.  Fix that.

Reported-by: Andy Lutomirski <luto@amacapital.net>
Tested-by: Alexander Tsoy <alexander@tsoy.me>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toralf Förster <toralf.foerster@gmx.de>
Cc: stable@vger.kernel.org
Fixes: 3b3fa11bc700 ("x86/dumpstack: Print any pt_regs found on the stack")
Link: http://lkml.kernel.org/r/396f84491d2f0ef64eda4217a2165f5712f6a115.1514736742.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-01-03 16:14:46 +01:00
Josh Poimboeuf
a9cdbe72c4 x86/dumpstack: Fix partial register dumps
The show_regs_safe() logic is wrong.  When there's an iret stack frame,
it prints the entire pt_regs -- most of which is random stack data --
instead of just the five registers at the end.

show_regs_safe() is also poorly named: the on_stack() checks aren't for
safety.  Rename the function to show_regs_if_on_stack() and add a
comment to explain why the checks are needed.

These issues were introduced with the "partial register dump" feature of
the following commit:

  b02fcf9ba121 ("x86/unwinder: Handle stack overflows more gracefully")

That patch had gone through a few iterations of development, and the
above issues were artifacts from a previous iteration of the patch where
'regs' pointed directly to the iret frame rather than to the (partially
empty) pt_regs.

Tested-by: Alexander Tsoy <alexander@tsoy.me>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toralf Förster <toralf.foerster@gmx.de>
Cc: stable@vger.kernel.org
Fixes: b02fcf9ba121 ("x86/unwinder: Handle stack overflows more gracefully")
Link: http://lkml.kernel.org/r/5b05b8b344f59db2d3d50dbdeba92d60f2304c54.1514736742.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-01-03 16:14:46 +01:00
Tom Lendacky
694d99d409 x86/cpu, x86/pti: Do not enable PTI on AMD processors
AMD processors are not subject to the types of attacks that the kernel
page table isolation feature protects against.  The AMD microarchitecture
does not allow memory references, including speculative references, that
access higher privileged data when running in a lesser privileged mode
when that access would result in a page fault.

Disable page table isolation by default on AMD processors by not setting
the X86_BUG_CPU_INSECURE feature, which controls whether X86_FEATURE_PTI
is set.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20171227054354.20369.94587.stgit@tlendack-t1.amdoffice.net
2018-01-03 15:57:59 +01:00
Dave Young
835bcec5fd x86/efi: Fix kernel param add_efi_memmap regression
'add_efi_memmap' is an early param, but do_add_efi_memmap() has no
chance to run because the code path is before parse_early_param().
I believe it worked when the param was introduced but probably later
some other changes caused the wrong order and nobody noticed it.

Move efi_memblock_x86_reserve_range() after parse_early_param()
to fix it.

Signed-off-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Bryan O'Donoghue <pure.logic@nexus-software.ie>
Cc: Ge Song <ge.song@hxt-semitech.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20180102172110.17018-2-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-01-03 13:54:31 +01:00
Linus Torvalds
f39d7d78b7 Merge branch 'x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
 "A couple of fixlets for x86:

   - Fix the ESPFIX double fault handling for 5-level pagetables

   - Fix the commandline parsing for 'apic=' on 32bit systems and update
     documentation

   - Make zombie stack traces reliable

   - Fix kexec with stack canary

   - Fix the delivery mode for APICs which was missed when the x86
     vector management was converted to single target delivery. Caused a
     regression due to the broken hardware which ignores affinity
     settings in lowest prio delivery mode.

   - Unbreak modules when AMD memory encryption is enabled

   - Remove an unused parameter of prepare_switch_to"

* 'x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/apic: Switch all APICs to Fixed delivery mode
  x86/apic: Update the 'apic=' description of setting APIC driver
  x86/apic: Avoid wrong warning when parsing 'apic=' in X86-32 case
  x86-32: Fix kexec with stack canary (CONFIG_CC_STACKPROTECTOR)
  x86: Remove unused parameter of prepare_switch_to
  x86/stacktrace: Make zombie stack traces reliable
  x86/mm: Unbreak modules that use the DMA API
  x86/build: Make isoimage work on Debian
  x86/espfix/64: Fix espfix double-fault handling on 5-level systems
2017-12-31 13:13:56 -08:00
Linus Torvalds
52c90f2d32 Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 page table isolation fixes from Thomas Gleixner:
 "Four patches addressing the PTI fallout as discussed and debugged
  yesterday:

   - Remove stale and pointless TLB flush invocations from the hotplug
     code

   - Remove stale preempt_disable/enable from __native_flush_tlb()

   - Plug the memory leak in the write_ldt() error path"

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/ldt: Make LDT pgtable free conditional
  x86/ldt: Plug memory leak in error path
  x86/mm: Remove preempt_disable/enable() from __native_flush_tlb()
  x86/smpboot: Remove stale TLB flush invocations
2017-12-31 13:03:05 -08:00
Linus Torvalds
88fa025d30 Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fixes from Thomas Gleixner:
 "A rather large update after the kaisered maintainer finally found time
  to handle regression reports.

   - The larger part addresses a regression caused by the x86 vector
     management rework.

     The reservation based model does not work reliably for MSI
     interrupts, if they cannot be masked (yes, yet another hw
     engineering trainwreck). The reason is that the reservation mode
     assigns a dummy vector when the interrupt is allocated and switches
     to a real vector when the interrupt is requested.

     If the MSI entry cannot be masked then the initialization might
     raise an interrupt before the interrupt is requested, which ends up
     as spurious interrupt and causes device malfunction and worse. The
     fix is to exclude MSI interrupts which do not support masking from
     reservation mode and assign a real vector right away.

   - Extend the extra lockdep class setup for nested interrupts with a
     class for the recently added irq_desc::request_mutex so lockdep can
     differeniate and does not emit false positive warnings.

   - A ratelimit guard for the bad irq printout so in case a bad irq
     comes back immediately the system does not drown in dmesg spam"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq/msi, x86/vector: Prevent reservation mode for non maskable MSI
  genirq/irqdomain: Rename early argument of irq_domain_activate_irq()
  x86/vector: Use IRQD_CAN_RESERVE flag
  genirq: Introduce IRQD_CAN_RESERVE flag
  genirq/msi: Handle reactivation only on success
  gpio: brcmstb: Make really use of the new lockdep class
  genirq: Guard handle_bad_irq log messages
  kernel/irq: Extend lockdep class for request mutex
2017-12-31 11:23:11 -08:00
Thomas Gleixner
7f414195b0 x86/ldt: Make LDT pgtable free conditional
Andy prefers to be paranoid about the pagetable free in the error path of
write_ldt(). Make it conditional and warn whenever the installment of a
secondary LDT fails.

Requested-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-12-31 16:55:09 +01:00
Thomas Gleixner
a62d69857a x86/ldt: Plug memory leak in error path
The error path in write_ldt() tries to free 'old_ldt' instead of the newly
allocated 'new_ldt', resulting in a memory leak. It also misses to clean up a
half populated LDT pagetable, which is not a leak as it gets cleaned up
when the process exits.

Free both the potentially half populated LDT pagetable and the newly
allocated LDT struct. This can be done unconditionally because once an LDT
is mapped subsequent maps will succeed, because the PTE page is already
populated and the two LDTs fit into that single page.

Reported-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linuxfoundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Fixes: f55f0501cbf6 ("x86/pti: Put the LDT in its own PGD if PTI is on")
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1712311121340.1899@nanos
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-31 12:14:07 +01:00