Skip to content

cloud-kernel
cloud-kernel

openanolis / cloud-kernel
1 年多 前同步成功

通知 160
Star 36
Fork 7
cloud-kernel
cloud-kernel
切换分支/标签
  1. 25 1月, 2017 4 次提交
  3. 24 1月, 2017 1 次提交
    • Y
      x86/fpu/xstate: Fix xcomp_bv in XSAVES header · dffba9a3
      由 Yu-cheng Yu 提交于 
      The compacted-format XSAVES area is determined at boot time and
never changed after.  The field xsave.header.xcomp_bv indicates
which components are in the fixed XSAVES format.

In fpstate_init() we did not set xcomp_bv to reflect the XSAVES
format since at the time there is no valid data.

However, after we do copy_init_fpstate_to_fpregs() in fpu__clear(),
as in commit:

  b22cbe40 x86/fpu: Fix invalid FPU ptrace state after execve()

and when __fpu_restore_sig() does fpu__restore() for a COMPAT-mode
app, a #GP occurs.  This can be easily triggered by doing valgrind on
a COMPAT-mode "Hello World," as reported by Joakim Tjernlund and
others:

	https://bugzilla.kernel.org/show_bug.cgi?id=190061

Fix it by setting xcomp_bv correctly.

This patch also moves the xcomp_bv initialization to the proper
place, which was in copyin_to_xsaves() as of:

  4c833368 x86/fpu: Set the xcomp_bv when we fake up a XSAVES area

which fixed the bug too, but it's more efficient and cleaner to
initialize things once per boot, not for every signal handling
operation.
Reported-by: NKevin Hao <haokexin@gmail.com>
Reported-by: NJoakim Tjernlund <Joakim.Tjernlund@infinera.com>
Signed-off-by: NYu-cheng Yu <yu-cheng.yu@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi V. Shankar <ravi.v.shankar@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: haokexin@gmail.com
Link: http://lkml.kernel.org/r/1485212084-4418-1-git-send-email-yu-cheng.yu@intel.com
[ Combined it with 4c833368. ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>
      dffba9a3
  5. 23 1月, 2017 1 次提交
    • K
      x86/fpu: Set the xcomp_bv when we fake up a XSAVES area · 4c833368
      由 Kevin Hao 提交于 
      I got the following calltrace on a Apollo Lake SoC with 32-bit kernel:

  WARNING: CPU: 2 PID: 261 at arch/x86/include/asm/fpu/internal.h:363 fpu__restore+0x1f5/0x260
  [...]
  Hardware name: Intel Corp. Broxton P/NOTEBOOK, BIOS APLIRVPA.X64.0138.B35.1608091058 08/09/2016
  Call Trace:
   dump_stack()
   __warn()
   ? fpu__restore()
   warn_slowpath_null()
   fpu__restore()
   __fpu__restore_sig()
   fpu__restore_sig()
   restore_sigcontext.isra.9()
   sys_sigreturn()
   do_int80_syscall_32()
   entry_INT80_32()

The reason is that a #GP occurs when executing XRSTORS. The root cause
is that we forget to set the xcomp_bv when we fake up the XSAVES area
in the copyin_to_xsaves() function.
Signed-off-by: NKevin Hao <haokexin@gmail.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yu-cheng Yu <yu-cheng.yu@intel.com>
Link: http://lkml.kernel.org/r/1485075023-30161-1-git-send-email-haokexin@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      4c833368
  7. 17 1月, 2017 1 次提交
  9. 21 11月, 2016 1 次提交
  11. 17 11月, 2016 1 次提交
  13. 01 11月, 2016 3 次提交
    • A
      x86/fpu: Remove irq_ts_save() and irq_ts_restore() · 5a83d60c
      由 Andy Lutomirski 提交于 
      Now that lazy FPU is gone, we don't use CR0.TS (except possibly in
KVM guest mode).  Remove irq_ts_save(), irq_ts_restore(), and all of
their callers.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kvm list <kvm@vger.kernel.org>
Link: http://lkml.kernel.org/r/70b9b9e7ba70659bedcb08aba63d0f9214f338f2.1477951965.git.luto@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
      5a83d60c
    • A
      x86/fpu: Stop saving and restoring CR0.TS in fpu__init_check_bugs() · fc560a80
      由 Andy Lutomirski 提交于 
      fpu__init_check_bugs() runs long after the early FPU init, so CR0.TS
will be clear by the time it runs.  The save-and-restore dance would
have been unnecessary anyway, though, as kernel_fpu_begin() would
have been good enough.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kvm list <kvm@vger.kernel.org>
Link: http://lkml.kernel.org/r/76d1f1eacb5caead98197d1eb50ac6110ab20c6a.1477951965.git.luto@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
      fc560a80
    • A
      x86/fpu: Get rid of two redundant clts() calls · 36fd4f02
      由 Andy Lutomirski 提交于 
      CR0.TS is cleared by a direct CR0 write in fpu__init_cpu_generic().
We don't need to call clts() two more times right after that.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kvm list <kvm@vger.kernel.org>
Link: http://lkml.kernel.org/r/476d2d5066eda24838853426ea74c94140b50c85.1477951965.git.luto@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
      36fd4f02
  15. 19 10月, 2016 1 次提交
    • P
      x86/cpufeature: Add AVX512_4VNNIW and AVX512_4FMAPS features · 82148993
      由 Piotr Luc 提交于 
      AVX512_4VNNIW  - Vector instructions for deep learning enhanced word
variable precision.
AVX512_4FMAPS - Vector instructions for deep learning floating-point
single precision.

These new instructions are to be used in future Intel Xeon & Xeon Phi
processors. The bits 2&3 of CPUID[level:0x07, EDX] inform that new
instructions are supported by a processor.

The spec can be found in the Intel Software Developer Manual (SDM) or in
the Instruction Set Extensions Programming Reference (ISE).

Define new feature flags to enumerate the new instructions in /proc/cpuinfo
accordingly to CPUID bits and add the required xsave extensions which are
required for proper operation.
Signed-off-by: NPiotr Luc <piotr.luc@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20161018150111.29926-1-piotr.luc@intel.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
      82148993
  17. 16 10月, 2016 1 次提交
    • R
      x86/fpu: Remove 'cpu' argument from __cpu_invalidate_fpregs_state() · 317b622c
      由 Rik van Riel 提交于 
      The __{fpu,cpu}_invalidate_fpregs_state() functions can only be used
to invalidate a resource they control.  Document that, and change
the API a little bit to reflect that.

Go back to open coding the fpu_fpregs_owner_ctx write in the CPU
hotplug code, which should be the exception, and move __kernel_fpu_begin()
to this API.

This patch has no functional changes to the current code.
Signed-off-by: NRik van Riel <riel@redhat.com>
Acked-by: NDave Hansen <dave.hansen@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1476447331-21566-2-git-send-email-riel@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      317b622c
  19. 07 10月, 2016 4 次提交
  21. 15 9月, 2016 1 次提交
  23. 09 9月, 2016 2 次提交
    • D
      x86/pkeys: Default to a restrictive init PKRU · acd547b2
      由 Dave Hansen 提交于 
      PKRU is the register that lets you disallow writes or all access to a given
protection key.

The XSAVE hardware defines an "init state" of 0 for PKRU: its most
permissive state, allowing access/writes to everything.  Since we start off
all new processes with the init state, we start all processes off with the
most permissive possible PKRU.

This is unfortunate.  If a thread is clone()'d [1] before a program has
time to set PKRU to a restrictive value, that thread will be able to write
to all data, no matter what pkey is set on it.  This weakens any integrity
guarantees that we want pkeys to provide.

To fix this, we define a very restrictive PKRU to override the
XSAVE-provided value when we create a new FPU context.  We choose a value
that only allows access to pkey 0, which is as restrictive as we can
practically make it.

This does not cause any practical problems with applications using
protection keys because we require them to specify initial permissions for
each key when it is allocated, which override the restrictive default.

In the end, this ensures that threads which do not know how to manage their
own pkey rights can not do damage to data which is pkey-protected.

I would have thought this was a pretty contrived scenario, except that I
heard a bug report from an MPX user who was creating threads in some very
early code before main().  It may be crazy, but folks evidently _do_ it.
Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com>
Cc: linux-arch@vger.kernel.org
Cc: Dave Hansen <dave@sr71.net>
Cc: mgorman@techsingularity.net
Cc: arnd@arndb.de
Cc: linux-api@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: luto@kernel.org
Cc: akpm@linux-foundation.org
Cc: torvalds@linux-foundation.org
Link: http://lkml.kernel.org/r/20160729163021.F3C25D4A@viggo.jf.intel.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
      acd547b2
    • D
      x86/pkeys: Allocation/free syscalls · e8c24d3a
      由 Dave Hansen 提交于 
      This patch adds two new system calls:

	int pkey_alloc(unsigned long flags, unsigned long init_access_rights)
	int pkey_free(int pkey);

These implement an "allocator" for the protection keys
themselves, which can be thought of as analogous to the allocator
that the kernel has for file descriptors.  The kernel tracks
which numbers are in use, and only allows operations on keys that
are valid.  A key which was not obtained by pkey_alloc() may not,
for instance, be passed to pkey_mprotect().

These system calls are also very important given the kernel's use
of pkeys to implement execute-only support.  These help ensure
that userspace can never assume that it has control of a key
unless it first asks the kernel.  The kernel does not promise to
preserve PKRU (right register) contents except for allocated
pkeys.

The 'init_access_rights' argument to pkey_alloc() specifies the
rights that will be established for the returned pkey.  For
instance:

	pkey = pkey_alloc(flags, PKEY_DENY_WRITE);

will allocate 'pkey', but also sets the bits in PKRU[1] such that
writing to 'pkey' is already denied.

The kernel does not prevent pkey_free() from successfully freeing
in-use pkeys (those still assigned to a memory range by
pkey_mprotect()).  It would be expensive to implement the checks
for this, so we instead say, "Just don't do it" since sane
software will never do it anyway.

Any piece of userspace calling pkey_alloc() needs to be prepared
for it to fail.  Why?  pkey_alloc() returns the same error code
(ENOSPC) when there are no pkeys and when pkeys are unsupported.
They can be unsupported for a whole host of reasons, so apps must
be prepared for this.  Also, libraries or LD_PRELOADs might steal
keys before an application gets access to them.

This allocation mechanism could be implemented in userspace.
Even if we did it in userspace, we would still need additional
user/kernel interfaces to tell userspace which keys are being
used by the kernel internally (such as for execute-only
mappings).  Having the kernel provide this facility completely
removes the need for these additional interfaces, or having an
implementation of this in userspace at all.

Note that we have to make changes to all of the architectures
that do not use mman-common.h because we use the new
PKEY_DENY_ACCESS/WRITE macros in arch-independent code.

1. PKRU is the Protection Key Rights User register.  It is a
   usermode-accessible register that controls whether writes
   and/or access to each individual pkey is allowed or denied.
Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com>
Acked-by: NMel Gorman <mgorman@techsingularity.net>
Cc: linux-arch@vger.kernel.org
Cc: Dave Hansen <dave@sr71.net>
Cc: arnd@arndb.de
Cc: linux-api@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: luto@kernel.org
Cc: akpm@linux-foundation.org
Cc: torvalds@linux-foundation.org
Link: http://lkml.kernel.org/r/20160729163015.444FE75F@viggo.jf.intel.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
      e8c24d3a
  25. 10 8月, 2016 1 次提交
    • D
      x86/mm/pkeys: Fix compact mode by removing protection keys' XSAVE buffer manipulation · b79daf85
      由 Dave Hansen 提交于 
      The Memory Protection Keys "rights register" (PKRU) is
XSAVE-managed, and is saved/restored along with the FPU state.

When kernel code accesses FPU regsisters, it does a delicate
dance with preempt.  Otherwise, the context switching code can
get confused as to whether the most up-to-date state is in the
registers themselves or in the XSAVE buffer.

But, PKRU is not a normal FPU register.  Using it does not
generate the normal device-not-available (#NM) exceptions which
means we can not manage it lazily, and the kernel completley
disallows using lazy mode when it is enabled.

The dance with preempt *only* occurs when managing the FPU
lazily.  Since we never manage PKRU lazily, we do not have to do
the dance with preempt; we can access it directly.  Doing it
this way saves a ton of complicated code (and is faster too).

Further, the XSAVES reenabling failed to patch a bit of code
in fpu__xfeature_set_state() the checked for compacted buffers.
That check caused fpu__xfeature_set_state() to silently refuse to
work when the kernel is using compacted XSAVE buffers.  This
broke execute-only and future pkey_mprotect() support when using
compact XSAVE buffers.

But, removing fpu__xfeature_set_state() gets rid of this issue,
in addition to the nice cleanup and speedup.

This fixes the same thing as a fix that Sai posted:

  https://lkml.org/lkml/2016/7/25/637

The fix that he posted is a much more obviously correct, but I
think we should just do this instead.
Reported-by: NSai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yu-Cheng Yu <yu-cheng.yu@intel.com>
Link: http://lkml.kernel.org/r/20160727232040.7D060DAD@viggo.jf.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      b79daf85
  27. 04 8月, 2016 1 次提交
    • M
      tree-wide: replace config_enabled() with IS_ENABLED() · 97f2645f
      由 Masahiro Yamada 提交于 
      The use of config_enabled() against config options is ambiguous.  In
practical terms, config_enabled() is equivalent to IS_BUILTIN(), but the
author might have used it for the meaning of IS_ENABLED().  Using
IS_ENABLED(), IS_BUILTIN(), IS_MODULE() etc.  makes the intention
clearer.

This commit replaces config_enabled() with IS_ENABLED() where possible.
This commit is only touching bool config options.

I noticed two cases where config_enabled() is used against a tristate
option:

 - config_enabled(CONFIG_HWMON)
  [ drivers/net/wireless/ath/ath10k/thermal.c ]

 - config_enabled(CONFIG_BACKLIGHT_CLASS_DEVICE)
  [ drivers/gpu/drm/gma500/opregion.c ]

I did not touch them because they should be converted to IS_BUILTIN()
in order to keep the logic, but I was not sure it was the authors'
intention.

Link: http://lkml.kernel.org/r/1465215656-20569-1-git-send-email-yamada.masahiro@socionext.comSigned-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: NKees Cook <keescook@chromium.org>
Cc: Stas Sergeev <stsp@list.ru>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Joshua Kinard <kumba@gentoo.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: "Dmitry V. Levin" <ldv@altlinux.org>
Cc: yu-cheng yu <yu-cheng.yu@intel.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Will Drewry <wad@chromium.org>
Cc: Nikolay Martynov <mar.kolya@gmail.com>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: Rafal Milecki <zajec5@gmail.com>
Cc: James Cowgill <James.Cowgill@imgtec.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Alex Smith <alex.smith@imgtec.com>
Cc: Adam Buchbinder <adam.buchbinder@gmail.com>
Cc: Qais Yousef <qais.yousef@imgtec.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Mikko Rapeli <mikko.rapeli@iki.fi>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: "Luis R. Rodriguez" <mcgrof@do-not-panic.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Kalle Valo <kvalo@qca.qualcomm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Tony Wu <tung7970@gmail.com>
Cc: Huaitong Han <huaitong.han@intel.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Juergen Gross <jgross@suse.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrea Gelmini <andrea.gelmini@gelma.net>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Rabin Vincent <rabin@rab.in>
Cc: "Maciej W. Rozycki" <macro@imgtec.com>
Cc: David Daney <david.daney@cavium.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      97f2645f
  29. 22 7月, 2016 1 次提交
    • D
      x86/fpu: Do not BUG_ON() in early FPU code · ec3ed4a2
      由 Dave Hansen 提交于 
      I don't think it is really possible to have a system where CPUID
enumerates support for XSAVE but that it does not have FP/SSE
(they are "legacy" features and always present).

But, I did manage to hit this case in qemu when I enabled its
somewhat shaky XSAVE support.  The bummer is that the FPU is set
up before we parse the command-line or have *any* console support
including earlyprintk.  That turned what should have been an easy
thing to debug in to a bit more of an odyssey.

So a BUG() here is worthless.  All it does it guarantee that
if/when we hit this case we have an empty console.  So, remove
the BUG() and try to limp along by disabling XSAVE and trying to
continue.  Add a comment on why we are doing this, and also add
a common "out_disable" path for leaving fpu__init_system_xstate().
Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160720194551.63BB2B58@viggo.jf.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      ec3ed4a2
  31. 11 7月, 2016 4 次提交
  33. 10 7月, 2016 5 次提交
  35. 18 6月, 2016 4 次提交
  37. 08 6月, 2016 1 次提交
    • D
      x86/fpu: Add tracepoints to dump FPU state at key points · d1898b73
      由 Dave Hansen 提交于 
      I've been carrying this patch around for a bit and it's helped me
solve at least a couple FPU-related bugs.  In addition to using
it for debugging, I also drug it out because using AVX (and
AVX2/AVX-512) can have serious power consequences for a modern
core.  It's very important to be able to figure out who is using
it.

It's also insanely useful to go out and see who is using a given
feature, like MPX or Memory Protection Keys.  If you, for
instance, want to find all processes using protection keys, you
can do:

	echo 'xfeatures & 0x200' > filter

Since 0x200 is the protection keys feature bit.

Note that this touches the KVM code.  KVM did a CREATE_TRACE_POINTS
and then included a bunch of random headers.  If anyone one of
those included other tracepoints, it would have defined the *OTHER*
tracepoints.  That's bogus, so move it to the right place.
Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160601174220.3CDFB90E@viggo.jf.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      d1898b73
  39. 13 4月, 2016 2 次提交