23120 Commits

Author SHA1 Message Date
Andy Lutomirski
72f924783b x86/entry, locking/lockdep: Move lockdep_sys_exit() to prepare_exit_to_usermode()
Rather than worrying about exactly where LOCKDEP_SYS_EXIT should
go in the asm code, add it to prepare_exit_from_usermode() and
remove all of the asm calls that are followed by
prepare_exit_to_usermode().

LOCKDEP_SYS_EXIT now appears only in the syscall fast paths.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1736ebe948b845e68120b86b89091f3ec27f5e8e.1444091584.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-07 11:34:07 +02:00
Andy Lutomirski
dd27f998f0 x86/entry/64/compat: Fix SYSENTER's NT flag before user memory access
Clearing NT is part of the prologue, whereas loading up arg6
makes more sense to think about as part of syscall processing.
Reorder them.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/19eb235828b2d2a52c53459e09f2974e15e65a35.1444091584.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-07 11:34:07 +02:00
Andy Lutomirski
7e0f51cb44 x86/uaccess: Add unlikely() to __chk_range_not_ok() failure paths
This should improve code quality a bit. It also shrinks the kernel text:

 Before:
       text     data      bss       dec    filename
   21828379  5194760  1277952  28301091    vmlinux

 After:
       text     data      bss       dec    filename
   21827997  5194760  1277952  28300709    vmlinux

... by 382 bytes.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/f427b8002d932e5deab9055e0074bb4e7e80ee39.1444091584.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-07 11:34:06 +02:00
Andy Lutomirski
a76cf66e94 x86/uaccess: Tell the compiler that uaccess is unlikely to fault
GCC doesn't realize that get_user(), put_user(), and their __
variants are unlikely to fail.  Tell it.

I noticed this while playing with the C entry code.

 Before:
       text     data      bss       dec    filename
   21828763  5194760  1277952  28301475    vmlinux.baseline

 After:
      text      data      bss       dec    filename
   21828379  5194760  1277952  28301091    vmlinux.new

The generated code shrunk by 384 bytes.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/dc37bed7024319c3004d950d57151fca6aeacf97.1444091584.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-07 11:34:06 +02:00
Ingo Molnar
25a9a924c0 Merge branch 'linus' into x86/asm, to pick up fixes before applying new changes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-07 11:24:24 +02:00
Taku Izumi
712df65ccb perf/x86/intel/uncore: Fix multi-segment problem of perf_event_intel_uncore
In multi-segment system, uncore devices may belong to buses whose segment
number is other than 0:

  ....
  0000:ff:10.5 System peripheral: Intel Corporation Xeon E5 v3/Core i7 Scratchpad & Semaphore Registers (rev 03)
  ...
  0001:7f:10.5 System peripheral: Intel Corporation Xeon E5 v3/Core i7 Scratchpad & Semaphore Registers (rev 03)
  ...
  0001:bf:10.5 System peripheral: Intel Corporation Xeon E5 v3/Core i7 Scratchpad & Semaphore Registers (rev 03)
  ...
  0001:ff:10.5 System peripheral: Intel Corporation Xeon E5 v3/Core i7 Scratchpad & Semaphore Registers (rev 03
  ...

In that case, relation of bus number and physical id may be broken
because "uncore_pcibus_to_physid" doesn't take account of PCI segment.
For example, bus 0000:ff and 0001:ff uses the same entry of
"uncore_pcibus_to_physid" array.

This patch fixes this problem by introducing the segment-aware pci2phy_map instead.

Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@kernel.org
Cc: hpa@zytor.com
Link: http://lkml.kernel.org/r/1443096621-4119-1-git-send-email-izumi.taku@jp.fujitsu.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-06 17:31:51 +02:00
Kan Liang
7ce1346a68 perf/x86: Add Intel cstate PMUs support
This patch adds new PMUs to support cstate related free running
(read-only) counters. These counters may be used simultaneously by other
tools, such as turbostat. However, it still make sense to implement them
in perf. Because we can conveniently collect them together with other
events, and allow to use them from tools without special MSR access
code.

These counters include CORE_C*_RESIDENCY and PKG_C*_RESIDENCY.
According to counters' scope and category, two PMUs are registered with
the perf_event core subsystem.

 - 'cstate_core': The counter is available for each physical core. The
                  counters include CORE_C*_RESIDENCY.

 - 'cstate_pkg':  The counter is available for each physical package. The
                  counters include PKG_C*_RESIDENCY.

The events are exposed in sysfs for use by perf stat and other tools.
The files are:

  /sys/devices/cstate_core/events/c*-residency
  /sys/devices/cstate_pkg/events/c*-residency

These events only support system-wide mode counting.
The /sys/devices/cstate_*/cpumask file can be used by tools to figure
out which CPUs to monitor by default.

The PMU type (attr->type) is dynamically allocated and is available from
/sys/devices/core_misc/type and /sys/device/cstate_*/type.

Sampling is not supported.

Here is an example.

 - To caculate the fraction of time when the core is running in C6 state
   CORE_C6_time% = CORE_C6_RESIDENCY / TSC

 # perf stat -x, -e"cstate_core/c6-residency/,msr/tsc/" -C0 -- taskset -c 0 sleep 5

   11838820015,,cstate_core/c6-residency/,5175919658,100.00
   11877130740,,msr/tsc/,5175922010,100.00

 For sleep, 99.7% of time we ran in C6 state.

 # perf stat -x, -e"cstate_core/c6-residency/,msr/tsc/" -C0 -- taskset -c 0 busyloop

   1253316,,cstate_core/c6-residency/,4360969154,100.00
   10012635248,,msr/tsc/,4360972366,100.00

 For busyloop, 0.01% of time we ran in C6 state.

Signed-off-by: Kan Liang <kan.liang@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@kernel.org
Cc: eranian@google.com
Link: http://lkml.kernel.org/r/1443443404-8581-1-git-send-email-kan.liang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-06 17:31:51 +02:00
Ingo Molnar
82fc167c39 Linux 4.3-rc4
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Merge tag 'v4.3-rc4' into locking/core, to pick up fixes before applying new changes

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-06 17:10:28 +02:00
Peter Zijlstra
d87b7a3379 sched/core, sched/x86: Kill thread_info::saved_preempt_count
With the introduction of the context switch preempt_count invariant,
and the demise of PREEMPT_ACTIVE, its pointless to save/restore the
per-cpu preemption count, it must always be 2.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-06 17:08:18 +02:00
Peter Zijlstra
609ca06638 sched/core: Create preempt_count invariant
Assuming units of PREEMPT_DISABLE_OFFSET for preempt_count() numbers.

Now that TASK_DEAD no longer results in preempt_count() == 3 during
scheduling, we will always call context_switch() with preempt_count()
== 2.

However, we don't always end up with preempt_count() == 2 in
finish_task_switch() because new tasks get created with
preempt_count() == 1.

Create FORK_PREEMPT_COUNT and set it to 2 and use that in the right
places. Note that we cannot use INIT_PREEMPT_COUNT as that serves
another purpose (boot).

After this, preempt_count() is invariant across the context switch,
with exception of PREEMPT_ACTIVE.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-06 17:08:14 +02:00
Linus Torvalds
f6702681a0 xen: bug fixes for 4.3-rc4
- Fix VM save performance regression with x86 PV guests.
 - Make kexec work in x86 PVHVM guests (if Xen has the soft-reset ABI).
 - Other minor fixes.
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Merge tag 'for-linus-4.3b-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen bug fixes from David Vrabel:

 - Fix VM save performance regression with x86 PV guests

 - Make kexec work in x86 PVHVM guests (if Xen has the soft-reset ABI)

 - Other minor fixes.

* tag 'for-linus-4.3b-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  x86/xen/p2m: hint at the last populated P2M entry
  x86/xen: Do not clip xen_e820_map to xen_e820_map_entries when sanitizing map
  x86/xen: Support kexec/kdump in HVM guests by doing a soft reset
  xen/x86: Don't try to write syscall-related MSRs for PV guests
  xen: use correct type for HYPERVISOR_memory_op()
2015-10-06 15:05:02 +01:00
David Vrabel
98dd166ea3 x86/xen/p2m: hint at the last populated P2M entry
With commit 633d6f17cd91ad5bf2370265946f716e42d388c6 (x86/xen: prepare
p2m list for memory hotplug) the P2M may be sized to accomdate a much
larger amount of memory than the domain currently has.

When saving a domain, the toolstack must scan all the P2M looking for
populated pages.  This results in a performance regression due to the
unnecessary scanning.

Instead of reporting (via shared_info) the maximum possible size of
the P2M, hint at the last PFN which might be populated.  This hint is
increased as new leaves are added to the P2M (in the expectation that
they will be used for populated entries).

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Cc: <stable@vger.kernel.org> # 4.0+
2015-10-06 13:54:20 +01:00
Stephen Smalley
e1a58320a3 x86/mm: Warn on W^X mappings
Warn on any residual W+X mappings after setting NX
if DEBUG_WX is enabled.  Introduce a separate
X86_PTDUMP_CORE config that enables the code for
dumping the page tables without enabling the debugfs
interface, so that DEBUG_WX can be enabled without
exposing the debugfs interface.  Switch EFI_PGT_DUMP
to using X86_PTDUMP_CORE so that it also does not require
enabling the debugfs interface.

On success it prints this to the kernel log:

  x86/mm: Checked W+X mappings: passed, no W+X pages found.

On failure it prints a warning and a count of the failed pages:

  ------------[ cut here ]------------
  WARNING: CPU: 1 PID: 1 at arch/x86/mm/dump_pagetables.c:226 note_page+0x610/0x7b0()
  x86/mm: Found insecure W+X mapping at address ffffffff81755000/__stop___ex_table+0xfa8/0xabfa8
  [...]
  Call Trace:
   [<ffffffff81380a5f>] dump_stack+0x44/0x55
   [<ffffffff8109d3f2>] warn_slowpath_common+0x82/0xc0
   [<ffffffff8109d48c>] warn_slowpath_fmt+0x5c/0x80
   [<ffffffff8106cfc9>] ? note_page+0x5c9/0x7b0
   [<ffffffff8106d010>] note_page+0x610/0x7b0
   [<ffffffff8106d409>] ptdump_walk_pgd_level_core+0x259/0x3c0
   [<ffffffff8106d5a7>] ptdump_walk_pgd_level_checkwx+0x17/0x20
   [<ffffffff81063905>] mark_rodata_ro+0xf5/0x100
   [<ffffffff817415a0>] ? rest_init+0x80/0x80
   [<ffffffff817415bd>] kernel_init+0x1d/0xe0
   [<ffffffff8174cd1f>] ret_from_fork+0x3f/0x70
   [<ffffffff817415a0>] ? rest_init+0x80/0x80
  ---[ end trace a1f23a1e42a2ac76 ]---
  x86/mm: Checked W+X mappings: FAILED, 171 W+X pages found.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1444064120-11450-1-git-send-email-sds@tycho.nsa.gov
[ Improved the Kconfig help text and made the new option default-y
  if CONFIG_DEBUG_RODATA=y, because it already found buggy mappings,
  so we really want people to have this on by default. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-06 11:11:48 +02:00
Ingo Molnar
38a413cbc2 Linux 4.3-rc3
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Merge tag 'v4.3-rc3' into x86/mm, to pick up fixes before applying new changes

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-06 10:56:54 +02:00
Linus Torvalds
2cf30826bb Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
 "Fixes all around the map: W+X kernel mapping fix, WCHAN fixes, two
  build failure fixes for corner case configs, x32 header fix and a
  speling fix"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/headers/uapi: Fix __BITS_PER_LONG value for x32 builds
  x86/mm: Set NX on gap between __ex_table and rodata
  x86/kexec: Fix kexec crash in syscall kexec_file_load()
  x86/process: Unify 32bit and 64bit implementations of get_wchan()
  x86/process: Add proper bound checks in 64bit get_wchan()
  x86, efi, kasan: Fix build failure on !KASAN && KMEMCHECK=y kernels
  x86/hyperv: Fix the build in the !CONFIG_KEXEC_CORE case
  x86/cpufeatures: Correct spelling of the HWP_NOTIFY flag
2015-10-03 10:53:05 -04:00
Linus Torvalds
a758379b03 Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull EFI fixes from Ingo Molnar:
 "Two EFI fixes: one for x86, one for ARM, fixing a boot crash bug that
  can trigger under newer EFI firmware"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  arm64/efi: Fix boot crash by not padding between EFI_MEMORY_RUNTIME regions
  x86/efi: Fix boot crash by mapping EFI memmap entries bottom-up at runtime, instead of top-down
2015-10-03 10:46:41 -04:00
Daniel Borkmann
a91263d520 ebpf: migrate bpf_prog's flags to bitfield
As we need to add further flags to the bpf_prog structure, lets migrate
both bools to a bitfield representation. The size of the base structure
(excluding insns) remains unchanged at 40 bytes.

Add also tags for the kmemchecker, so that it doesn't throw false
positives. Even in case gcc would generate suboptimal code, it's not
being accessed in performance critical paths.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-03 05:02:39 -07:00
Ben Hutchings
f4b4aae182 x86/headers/uapi: Fix __BITS_PER_LONG value for x32 builds
On x32, gcc predefines __x86_64__ but long is only 32-bit.  Use
__ILP32__ to distinguish x32.

Fixes this compiler error in perf:

	tools/include/asm-generic/bitops/__ffs.h: In function '__ffs':
	tools/include/asm-generic/bitops/__ffs.h:19:8: error: right shift count >= width of type [-Werror=shift-count-overflow]
	  word >>= 32;
	       ^

This isn't sufficient to build perf for x32, though.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1443660043.2730.15.camel@decadent.org.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-02 09:43:21 +02:00
Stephen Smalley
ab76f7b4ab x86/mm: Set NX on gap between __ex_table and rodata
Unused space between the end of __ex_table and the start of
rodata can be left W+x in the kernel page tables.  Extend the
setting of the NX bit to cover this gap by starting from
text_end rather than rodata_start.

  Before:
  ---[ High Kernel Mapping ]---
  0xffffffff80000000-0xffffffff81000000          16M                               pmd
  0xffffffff81000000-0xffffffff81600000           6M     ro         PSE     GLB x  pmd
  0xffffffff81600000-0xffffffff81754000        1360K     ro                 GLB x  pte
  0xffffffff81754000-0xffffffff81800000         688K     RW                 GLB x  pte
  0xffffffff81800000-0xffffffff81a00000           2M     ro         PSE     GLB NX pmd
  0xffffffff81a00000-0xffffffff81b3b000        1260K     ro                 GLB NX pte
  0xffffffff81b3b000-0xffffffff82000000        4884K     RW                 GLB NX pte
  0xffffffff82000000-0xffffffff82200000           2M     RW         PSE     GLB NX pmd
  0xffffffff82200000-0xffffffffa0000000         478M                               pmd

  After:
  ---[ High Kernel Mapping ]---
  0xffffffff80000000-0xffffffff81000000          16M                               pmd
  0xffffffff81000000-0xffffffff81600000           6M     ro         PSE     GLB x  pmd
  0xffffffff81600000-0xffffffff81754000        1360K     ro                 GLB x  pte
  0xffffffff81754000-0xffffffff81800000         688K     RW                 GLB NX pte
  0xffffffff81800000-0xffffffff81a00000           2M     ro         PSE     GLB NX pmd
  0xffffffff81a00000-0xffffffff81b3b000        1260K     ro                 GLB NX pte
  0xffffffff81b3b000-0xffffffff82000000        4884K     RW                 GLB NX pte
  0xffffffff82000000-0xffffffff82200000           2M     RW         PSE     GLB NX pmd
  0xffffffff82200000-0xffffffffa0000000         478M                               pmd

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: <stable@vger.kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1443704662-3138-1-git-send-email-sds@tycho.nsa.gov
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-02 09:21:06 +02:00
Lee, Chun-Yi
e3c41e37b0 x86/kexec: Fix kexec crash in syscall kexec_file_load()
The original bug is a page fault crash that sometimes happens
on big machines when preparing ELF headers:

    BUG: unable to handle kernel paging request at ffffc90613fc9000
    IP: [<ffffffff8103d645>] prepare_elf64_ram_headers_callback+0x165/0x260

The bug is caused by us under-counting the number of memory ranges
and subsequently not allocating enough ELF header space for them.
The bug is typically masked on smaller systems, because the ELF header
allocation is rounded up to the next page.

This patch modifies the code in fill_up_crash_elf_data() by using
walk_system_ram_res() instead of walk_system_ram_range() to correctly
count the max number of crash memory ranges. That's because the
walk_system_ram_range() filters out small memory regions that
reside in the same page, but walk_system_ram_res() does not.

Here's how I found the bug:

After tracing prepare_elf64_headers() and prepare_elf64_ram_headers_callback(),
the code uses walk_system_ram_res() to fill-in crash memory regions information
to the program header, so it counts those small memory regions that
reside in a page area.

But, when the kernel was using walk_system_ram_range() in
fill_up_crash_elf_data() to count the number of crash memory regions,
it filters out small regions.

I printed those small memory regions, for example:

  kexec: Get nr_ram ranges. vaddr=0xffff880077592258 paddr=0x77592258, sz=0xdc0

Based on the code in walk_system_ram_range(), this memory region
will be filtered out:

  pfn = (0x77592258 + 0x1000 - 1) >> 12 = 0x77593
  end_pfn = (0x77592258 + 0xfc0 -1 + 1) >> 12 = 0x77593
  end_pfn - pfn = 0x77593 - 0x77593 = 0  <=== if (end_pfn > pfn) is FALSE

So, the max_nr_ranges that's counted by the kernel doesn't include
small memory regions - causing us to under-allocate the required space.
That causes the page fault crash that happens in a later code path
when preparing ELF headers.

This bug is not easy to reproduce on small machines that have few
CPUs, because the allocated page aligned ELF buffer has more free
space to cover those small memory regions' PT_LOAD headers.

Signed-off-by: Lee, Chun-Yi <jlee@suse.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: kexec@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/1443531537-29436-1-git-send-email-jlee@suse.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-02 09:13:06 +02:00
Linus Torvalds
bde17b90dd Merge branch 'akpm' (patches from Andrew)
Merge misc fixes from Andrew Morton:
 "12 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  dmapool: fix overflow condition in pool_find_page()
  thermal: avoid division by zero in power allocator
  memcg: remove pcp_counter_lock
  kprobes: use _do_fork() in samples to make them work again
  drivers/input/joystick/Kconfig: zhenhua.c needs BITREVERSE
  memcg: make mem_cgroup_read_stat() unsigned
  memcg: fix dirty page migration
  dax: fix NULL pointer in __dax_pmd_fault()
  mm: hugetlbfs: skip shared VMAs when unmapping private pages to satisfy a fault
  mm/slab: fix unexpected index mapping result of kmalloc_size(INDEX_NODE+1)
  userfaultfd: remove kernel header include from uapi header
  arch/x86/include/asm/efi.h: fix build failure
2015-10-01 22:20:11 -04:00
Andrey Ryabinin
a523841ee4 arch/x86/include/asm/efi.h: fix build failure
With KMEMCHECK=y, KASAN=n:

  arch/x86/platform/efi/efi.c:673:3: error: implicit declaration of function `memcpy' [-Werror=implicit-function-declaration]
  arch/x86/platform/efi/efi_64.c:139:2: error: implicit declaration of function `memcpy' [-Werror=implicit-function-declaration]
  arch/x86/include/asm/desc.h:121:2: error: implicit declaration of function `memcpy' [-Werror=implicit-function-declaration]

Don't #undef memcpy if KASAN=n.

Fixes: 769a8089c1fd ("x86, efi, kasan: #undef memset/memcpy/memmove per arch")
Signed-off-by: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Reported-by: Ingo Molnar <mingo@kernel.org>
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-10-01 21:42:35 -04:00
Linus Torvalds
ccf70ddcbe (Relatively) a lot of reverts, mostly.
Bugs have trickled in for a new feature in 4.2 (MTRR support in guests)
 so I'm reverting it all; let's not make this -rc period busier for KVM
 than it's been so far.  This covers the four reverts from me.
 
 The fifth patch is being reverted because Radim found a bug in the
 implementation of stable scheduler clock, *but* also managed to implement
 the feature entirely without hypervisor support.  So instead of fixing
 the hypervisor side we can remove it completely; 4.4 will get the new
 implementation.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM fixes from Paolo Bonzini:
 "(Relatively) a lot of reverts, mostly.

  Bugs have trickled in for a new feature in 4.2 (MTRR support in
  guests) so I'm reverting it all; let's not make this -rc period busier
  for KVM than it's been so far.  This covers the four reverts from me.

  The fifth patch is being reverted because Radim found a bug in the
  implementation of stable scheduler clock, *but* also managed to
  implement the feature entirely without hypervisor support.  So instead
  of fixing the hypervisor side we can remove it completely; 4.4 will
  get the new implementation"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  Use WARN_ON_ONCE for missing X86_FEATURE_NRIPS
  Update KVM homepage Url
  Revert "KVM: SVM: use NPT page attributes"
  Revert "KVM: svm: handle KVM_X86_QUIRK_CD_NW_CLEARED in svm_get_mt_mask"
  Revert "KVM: SVM: Sync g_pat with guest-written PAT value"
  Revert "KVM: x86: apply guest MTRR virtualization on host reserved pages"
  Revert "KVM: x86: zero kvmclock_offset when vcpu0 initializes kvmclock system MSR"
2015-10-01 16:43:25 -04:00
Feng Wu
bf9f6ac8d7 KVM: Update Posted-Interrupts Descriptor when vCPU is blocked
This patch updates the Posted-Interrupts Descriptor when vCPU
is blocked.

pre-block:
- Add the vCPU to the blocked per-CPU list
- Set 'NV' to POSTED_INTR_WAKEUP_VECTOR

post-block:
- Remove the vCPU from the per-CPU list

Signed-off-by: Feng Wu <feng.wu@intel.com>
[Concentrate invocation of pre/post-block hooks to vcpu_block. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:53 +02:00
Feng Wu
28b835d60f KVM: Update Posted-Interrupts Descriptor when vCPU is preempted
This patch updates the Posted-Interrupts Descriptor when vCPU
is preempted.

sched out:
- Set 'SN' to suppress furture non-urgent interrupts posted for
the vCPU.

sched in:
- Clear 'SN'
- Change NDST if vCPU is scheduled to a different CPU
- Set 'NV' to POSTED_INTR_VECTOR

Signed-off-by: Feng Wu <feng.wu@intel.com>
[Include asm/cpu.h to fix !CONFIG_SMP compilation. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:53 +02:00
Feng Wu
8727688006 KVM: x86: select IRQ_BYPASS_MANAGER
Select IRQ_BYPASS_MANAGER for x86 when CONFIG_KVM is set

Signed-off-by: Feng Wu <feng.wu@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:52 +02:00
Feng Wu
efc644048e KVM: x86: Update IRTE for posted-interrupts
This patch adds the routine to update IRTE for posted-interrupts
when guest changes the interrupt configuration.

Signed-off-by: Feng Wu <feng.wu@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
[Squashed in automatically generated patch from the build robot
 "KVM: x86: vcpu_to_pi_desc() can be static" - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:51 +02:00
Feng Wu
d84f1e0755 KVM: make kvm_set_msi_irq() public
Make kvm_set_msi_irq() public, we can use this function outside.

Signed-off-by: Feng Wu <feng.wu@intel.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:50 +02:00
Feng Wu
8feb4a04dc KVM: Define a new interface kvm_intr_is_single_vcpu()
This patch defines a new interface kvm_intr_is_single_vcpu(),
which can returns whether the interrupt is for single-CPU or not.

It is used by VT-d PI, since now we only support single-CPU
interrupts, For lowest-priority interrupts, if user configures
it via /proc/irq or uses irqbalance to make it single-CPU, we
can use PI to deliver the interrupts to it. Full functionality
of lowest-priority support will be added later.

Signed-off-by: Feng Wu <feng.wu@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:49 +02:00
Feng Wu
ebbfc76536 KVM: Add some helper functions for Posted-Interrupts
This patch adds some helper functions to manipulate the
Posted-Interrupts Descriptor.

Signed-off-by: Feng Wu <feng.wu@intel.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
[Make the new functions inline. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:48 +02:00
Feng Wu
6ef1522f7e KVM: Extend struct pi_desc for VT-d Posted-Interrupts
Extend struct pi_desc for VT-d Posted-Interrupts.

Signed-off-by: Feng Wu <feng.wu@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:48 +02:00
Paolo Bonzini
18cd52c4d9 irq_remapping: move structs outside #ifdef
This is friendlier to clients of the code, who are going to prepare
vcpu_data structs unconditionally, even if CONFIG_IRQ_REMAP is not
defined.

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:42 +02:00
Radim Krčmář
72c930dcfc x86: kvmclock: abolish PVCLOCK_COUNTS_FROM_ZERO
Newer KVM won't be exposing PVCLOCK_COUNTS_FROM_ZERO anymore.
The purpose of that flags was to start counting system time from 0 when
the KVM clock has been initialized.
We can achieve the same by selecting one read as the initial point.

A simple subtraction will work unless the KVM clock count overflows
earlier (has smaller width) than scheduler's cycle count.  We should be
safe till x86_128.

Because PVCLOCK_COUNTS_FROM_ZERO was enabled only on new hypervisors,
setting sched clock as stable based on PVCLOCK_TSC_STABLE_BIT might
regress on older ones.

I presume we don't need to change kvm_clock_read instead of introducing
kvm_sched_clock_read.  A problem could arise in case sched_clock is
expected to return the same value as get_cycles, but we should have
merged those clocks in that case.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Acked-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:42 +02:00
Xiao Guangrong
1cea0ce68e KVM: VMX: drop rdtscp_enabled field
Check cpuid bit instead of it

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:41 +02:00
Xiao Guangrong
7ec362964d KVM: VMX: clean up bit operation on SECONDARY_VM_EXEC_CONTROL
Use vmcs_set_bits() and vmcs_clear_bits() to clean up the code

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:40 +02:00
Xiao Guangrong
feda805fe7 KVM: VMX: unify SECONDARY_VM_EXEC_CONTROL update
Unify the update in vmx_cpuid_update()

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
[Rewrite to use vmcs_set_secondary_exec_control. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:39 +02:00
Paolo Bonzini
8b97265a15 KVM: VMX: align vmx->nested.nested_vmx_secondary_ctls_high to vmx->rdtscp_enabled
The SECONDARY_EXEC_RDTSCP must be available iff RDTSCP is enabled in the
guest.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:38 +02:00
Xiao Guangrong
29541bb8f4 KVM: VMX: simplify invpcid handling in vmx_cpuid_update()
If vmx_invpcid_supported() is true, second execution control
filed must be supported and SECONDARY_EXEC_ENABLE_INVPCID
must have already been set in current vmcs by
vmx_secondary_exec_control()

If vmx_invpcid_supported() is false, no need to clear
SECONDARY_EXEC_ENABLE_INVPCID

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:38 +02:00
Xiao Guangrong
f36201e5f4 KVM: VMX: simplify rdtscp handling in vmx_cpuid_update()
if vmx_rdtscp_supported() is true SECONDARY_EXEC_RDTSCP must
have already been set in current vmcs by
vmx_secondary_exec_control()

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:37 +02:00
Xiao Guangrong
e2821620c0 KVM: VMX: drop rdtscp_enabled check in prepare_vmcs02()
SECONDARY_EXEC_RDTSCP set for L2 guest comes from vmcs12

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:36 +02:00
Xiao Guangrong
8b3e34e46a KVM: x86: add pcommit support
Pass PCOMMIT CPU feature to guest to enable PCOMMIT instruction

Currently we do not catch pcommit instruction for L1 guest and
allow L1 to catch this instruction for L2 if, as required by the spec,
L1 can enumerate the PCOMMIT instruction via CPUID:
| IA32_VMX_PROCBASED_CTLS2[53] (which enumerates support for the
| 1-setting of PCOMMIT exiting) is always the same as
| CPUID.07H:EBX.PCOMMIT[bit 22]. Thus, software can set PCOMMIT exiting
| to 1 if and only if the PCOMMIT instruction is enumerated via CPUID

The spec can be found at
https://software.intel.com/sites/default/files/managed/0d/53/319433-022.pdf

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:35 +02:00
Xiao Guangrong
eb1c31b468 KVM: x86: allow guest to use cflushopt and clwb
Pass these CPU features to guest to enable them in guest

They are needed by nvdimm drivers

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:35 +02:00
Paolo Bonzini
d6a858d13e KVM: vmx: disable posted interrupts if no local APIC
Uniprocessor 32-bit randconfigs can disable the local APIC, and posted
interrupts require reserving a vector on the LAPIC, so they are
incompatible.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:34 +02:00
Andrey Smetanin
9eec50b8bb kvm/x86: Hyper-V HV_X64_MSR_VP_RUNTIME support
HV_X64_MSR_VP_RUNTIME msr used by guest to get
"the time the virtual processor consumes running guest code,
and the time the associated logical processor spends running
hypervisor code on behalf of that guest."

Calculation of this time is performed by task_cputime_adjusted()
for vcpu task.

Necessary to support loading of winhv.sys in guest, which in turn is
required to support Windows VMBus.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Gleb Natapov <gleb@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:33 +02:00
Andrey Smetanin
11c4b1ca71 kvm/x86: Hyper-V HV_X64_MSR_VP_INDEX export for QEMU.
Insert Hyper-V HV_X64_MSR_VP_INDEX into msr's emulated list,
so QEMU can set Hyper-V features cpuid HV_X64_MSR_VP_INDEX_AVAILABLE
bit correctly. KVM emulation part is in place already.

Necessary to support loading of winhv.sys in guest, which in turn is
required to support Windows VMBus.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Gleb Natapov <gleb@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:32 +02:00
Andrey Smetanin
e516cebb4f kvm/x86: Hyper-V HV_X64_MSR_RESET msr
HV_X64_MSR_RESET msr is used by Hyper-V based Windows guest
to reset guest VM by hypervisor.

Necessary to support loading of winhv.sys in guest, which in turn is
required to support Windows VMBus.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Gleb Natapov <gleb@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:32 +02:00
Jason Wang
931c33b178 kvm: add tracepoint for fast mmio
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:30 +02:00
Steve Rutherford
1c1a9ce973 KVM: x86: Add support for local interrupt requests from userspace
In order to enable userspace PIC support, the userspace PIC needs to
be able to inject local interrupts even when the APICs are in the
kernel.

KVM_INTERRUPT now supports sending local interrupts to an APIC when
APICs are in the kernel.

The ready_for_interrupt_request flag is now only set when the CPU/APIC
will immediately accept and inject an interrupt (i.e. APIC has not
masked the PIC).

When the PIC wishes to initiate an INTA cycle with, say, CPU0, it
kicks CPU0 out of the guest, and renedezvous with CPU0 once it arrives
in userspace.

When the CPU/APIC unmasks the PIC, a KVM_EXIT_IRQ_WINDOW_OPEN is
triggered, so that userspace has a chance to inject a PIC interrupt
if it had been pending.

Overall, this design can lead to a small number of spurious userspace
renedezvous. In particular, whenever the PIC transistions from low to
high while it is masked and whenever the PIC becomes unmasked while
it is low.

Note: this does not buffer more than one local interrupt in the
kernel, so the VMM needs to enter the guest in order to complete
interrupt injection before injecting an additional interrupt.

Compiles for x86.

Can pass the KVM Unit Tests.

Signed-off-by: Steve Rutherford <srutherford@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:29 +02:00
Steve Rutherford
b053b2aef2 KVM: x86: Add EOI exit bitmap inference
In order to support a userspace IOAPIC interacting with an in kernel
APIC, the EOI exit bitmaps need to be configurable.

If the IOAPIC is in userspace (i.e. the irqchip has been split), the
EOI exit bitmaps will be set whenever the GSI Routes are configured.
In particular, for the low MSI routes are reservable for userspace
IOAPICs. For these MSI routes, the EOI Exit bit corresponding to the
destination vector of the route will be set for the destination VCPU.

The intention is for the userspace IOAPICs to use the reservable MSI
routes to inject interrupts into the guest.

This is a slight abuse of the notion of an MSI Route, given that MSIs
classically bypass the IOAPIC. It might be worthwhile to add an
additional route type to improve clarity.

Compile tested for Intel x86.

Signed-off-by: Steve Rutherford <srutherford@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:28 +02:00
Steve Rutherford
7543a635aa KVM: x86: Add KVM exit for IOAPIC EOIs
Adds KVM_EXIT_IOAPIC_EOI which allows the kernel to EOI
level-triggered IOAPIC interrupts.

Uses a per VCPU exit bitmap to decide whether or not the IOAPIC needs
to be informed (which is identical to the EOI_EXIT_BITMAP field used
by modern x86 processors, but can also be used to elide kvm IOAPIC EOI
exits on older processors).

[Note: A prototype using ResampleFDs found that decoupling the EOI
from the VCPU's thread made it possible for the VCPU to not see a
recent EOI after reentering the guest. This does not match real
hardware.]

Compile tested for Intel x86.

Signed-off-by: Steve Rutherford <srutherford@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:27 +02:00