linux-toradex.git/arch/x86, branch v4.15

Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2018-01-28T20:24:36+00:00

Pull x86 retpoline fixlet from Thomas Gleixner:
 "Remove the ESP/RSP thunks for retpoline as they cannot ever work.

  Get rid of them before they show up in a release"

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/retpoline: Remove the esp/rsp thunk

Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2018-01-28T20:19:23+00:00

Pull x86 fixes from Thomas Gleixner:
 "A set of small fixes for 4.15:

   - Fix vmapped stack synchronization on systems with 4-level paging
     and a large amount of memory caused by a missing 5-level folding
     which made the pgd synchronization logic to fail and causing double
     faults.

   - Add a missing sanity check in the vmalloc_fault() logic on 5-level
     paging systems.

   - Bring back protection against accessing a freed initrd in the
     microcode loader which was lost by a wrong merge conflict
     resolution.

   - Extend the Broadwell micro code loading sanity check.

   - Add a missing ENDPROC annotation in ftrace assembly code which
     makes ORC unhappy.

   - Prevent loading the AMD power module on !AMD platforms. The load
     itself is uncritical, but an unload attempt results in a kernel
     crash.

   - Update Peter Anvins role in the MAINTAINERS file"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/ftrace: Add one more ENDPROC annotation
  x86: Mark hpa as a "Designated Reviewer" for the time being
  x86/mm/64: Tighten up vmalloc_fault() sanity checks on 5-level kernels
  x86/mm/64: Fix vmapped stack syncing on very-large-memory 4-level systems
  x86/microcode: Fix again accessing initrd after having been freed
  x86/microcode/intel: Extend BDW late-loading further with LLC size check
  perf/x86/amd/power: Do not load AMD power module on !AMD platforms

Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2018-01-28T19:48:25+00:00

Pull perf fixes from Thomas Gleixner:
 "Four patches which all address lock inversions and deadlocks in the
  perf core code and the Intel debug store"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86: Fix perf,x86,cpuhp deadlock
  perf/core: Fix ctx::mutex deadlock
  perf/core: Fix another perf,trace,cpuhp lock inversion
  perf/core: Fix lock inversion between perf,trace,cpuhp

x86/ftrace: Add one more ENDPROC annotation

2018-01-28T08:19:12+00:00

When ORC support was added for the ftrace_64.S code, an ENDPROC
for function_hook() was missed. This results in the following warning:

  arch/x86/kernel/ftrace_64.o: warning: objtool: .entry.text+0x0: unreachable instruction

Fixes: e2ac83d74a4d ("x86/ftrace: Fix ORC unwinding from ftrace handlers")
Reported-by: Steven Rostedt 
Reported-by: Borislav Petkov 
Signed-off-by: Josh Poimboeuf 
Signed-off-by: Thomas Gleixner 
Acked-by: Ingo Molnar 
Cc: Linus Torvalds 
Link: https://lkml.kernel.org/r/20180128022150.dqierscqmt3uwwsr@treble

x86/mm/64: Tighten up vmalloc_fault() sanity checks on 5-level kernels

2018-01-26T14:56:23+00:00

On a 5-level kernel, if a non-init mm has a top-level entry, it needs to
match init_mm's, but the vmalloc_fault() code skipped over the BUG_ON()
that would have checked it.

While we're at it, get rid of the rather confusing 4-level folded "pgd"
logic.

Cleans-up: b50858ce3e2a ("x86/mm/vmalloc: Add 5-level paging support")
Signed-off-by: Andy Lutomirski 
Signed-off-by: Thomas Gleixner 
Cc: Konstantin Khlebnikov 
Cc: Dave Hansen 
Cc: Borislav Petkov 
Cc: Neil Berrington 
Link: https://lkml.kernel.org/r/2ae598f8c279b0a29baf75df207e6f2fdddc0a1b.1516914529.git.luto@kernel.org

x86/mm/64: Fix vmapped stack syncing on very-large-memory 4-level systems

2018-01-26T14:56:23+00:00

Neil Berrington reported a double-fault on a VM with 768GB of RAM that uses
large amounts of vmalloc space with PTI enabled.

The cause is that load_new_mm_cr3() was never fixed to take the 5-level pgd
folding code into account, so, on a 4-level kernel, the pgd synchronization
logic compiles away to exactly nothing.

Interestingly, the problem doesn't trigger with nopti.  I assume this is
because the kernel is mapped with global pages if we boot with nopti.  The
sequence of operations when we create a new task is that we first load its
mm while still running on the old stack (which crashes if the old stack is
unmapped in the new mm unless the TLB saves us), then we call
prepare_switch_to(), and then we switch to the new stack.
prepare_switch_to() pokes the new stack directly, which will populate the
mapping through vmalloc_fault().  I assume that we're getting lucky on
non-PTI systems -- the old stack's TLB entry stays alive long enough to
make it all the way through prepare_switch_to() and switch_to() so that we
make it to a valid stack.

Fixes: b50858ce3e2a ("x86/mm/vmalloc: Add 5-level paging support")
Reported-and-tested-by: Neil Berrington 
Signed-off-by: Andy Lutomirski 
Signed-off-by: Thomas Gleixner 
Cc: Konstantin Khlebnikov 
Cc: stable@vger.kernel.org
Cc: Dave Hansen 
Cc: Borislav Petkov 
Link: https://lkml.kernel.org/r/346541c56caed61abbe693d7d2742b4a380c5001.1516914529.git.luto@kernel.org

perf/x86: Fix perf,x86,cpuhp deadlock

2018-01-25T13:48:30+00:00

More lockdep gifts, a 5-way lockup race:

	perf_event_create_kernel_counter()
	  perf_event_alloc()
	    perf_try_init_event()
	      x86_pmu_event_init()
		__x86_pmu_event_init()
		  x86_reserve_hardware()
 #0		    mutex_lock(&pmc_reserve_mutex);
		    reserve_ds_buffer()
 #1		      get_online_cpus()

	perf_event_release_kernel()
	  _free_event()
	    hw_perf_event_destroy()
	      x86_release_hardware()
 #0		mutex_lock(&pmc_reserve_mutex)
		release_ds_buffer()
 #1		  get_online_cpus()

 #1	do_cpu_up()
	  perf_event_init_cpu()
 #2	    mutex_lock(&pmus_lock)
 #3	    mutex_lock(&ctx->mutex)

	sys_perf_event_open()
	  mutex_lock_double()
 #3	    mutex_lock(ctx->mutex)
 #4	    mutex_lock_nested(ctx->mutex, 1);

	perf_try_init_event()
 #4	  mutex_lock_nested(ctx->mutex, 1)
	  x86_pmu_event_init()
	    intel_pmu_hw_config()
	      x86_add_exclusive()
 #0		mutex_lock(&pmc_reserve_mutex)

Fix it by using ordering constructs instead of locking.

Signed-off-by: Peter Zijlstra (Intel) 
Cc: Alexander Shishkin 
Cc: Arnaldo Carvalho de Melo 
Cc: Jiri Olsa 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: Thomas Gleixner 
Cc: Vince Weaver 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

Merge tag 'trace-v4.15-rc9' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2018-01-24T18:08:16+00:00

Pull tracing fixes from Steven Rostedt:
 "With the new ORC unwinder, ftrace stack tracing became disfunctional.

  One was that ORC didn't know how to handle the ftrace callbacks in
  general (which Josh fixed).

  The other was that ORC would just bail if it hit a dynamically
  allocated trampoline. Which means all ftrace stack tracing that
  happens from the function tracer would produce no results (that
  includes killing the max stack size tracer). I added a check to the
  ORC unwinder to see if the trampoline belonged to ftrace, and if it
  did, use the orc entry of the static trampoline that was used to
  create the dynamic one (it would be identical).

  Finally, I noticed that the skip values of the stack tracing were out
  of whack. I went through and fixed them up"

* tag 'trace-v4.15-rc9' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Update stack trace skipping for ORC unwinder
  ftrace, orc, x86: Handle ftrace dynamically allocated trampolines
  x86/ftrace: Fix ORC unwinding from ftrace handlers

x86/microcode: Fix again accessing initrd after having been freed

2018-01-24T12:00:35+00:00

Commit 24c2503255d3 ("x86/microcode: Do not access the initrd after it has
been freed") fixed attempts to access initrd from the microcode loader
after it has been freed. However, a similar KASAN warning was reported
(stack trace edited):

  smpboot: Booting Node 0 Processor 1 APIC 0x11
  ==================================================================
  BUG: KASAN: use-after-free in find_cpio_data+0x9b5/0xa50
  Read of size 1 at addr ffff880035ffd000 by task swapper/1/0

  CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.14.8-slack #7
  Hardware name: System manufacturer System Product Name/A88X-PLUS, BIOS 3003 03/10/2016
  Call Trace:
   dump_stack
   print_address_description
   kasan_report
   ? find_cpio_data
   __asan_report_load1_noabort
   find_cpio_data
   find_microcode_in_initrd
   __load_ucode_amd
   load_ucode_amd_ap
      load_ucode_ap

After some investigation, it turned out that a merge was done using the
wrong side to resolve, leading to picking up the previous state, before
the 24c2503255d3 fix. Therefore the Fixes tag below contains a merge
commit.

Revert the mismerge by catching the save_microcode_in_initrd_amd()
retval and thus letting the function exit with the last return statement
so that initrd_gone can be set to true.

Fixes: f26483eaedec ("Merge branch 'x86/urgent' into x86/microcode, to resolve conflicts")
Reported-by: 
Signed-off-by: Borislav Petkov 
Signed-off-by: Thomas Gleixner 
Cc: stable@vger.kernel.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=198295
Link: https://lkml.kernel.org/r/20180123104133.918-2-bp@alien8.de

x86/microcode/intel: Extend BDW late-loading further with LLC size check

2018-01-24T12:00:35+00:00

Commit b94b73733171 ("x86/microcode/intel: Extend BDW late-loading with a
revision check") reduced the impact of erratum BDF90 for Broadwell model
79.

The impact can be reduced further by checking the size of the last level
cache portion per core.

Tony: "The erratum says the problem only occurs on the large-cache SKUs.
So we only need to avoid the update if we are on a big cache SKU that is
also running old microcode."

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

Fixes: b94b73733171 ("x86/microcode/intel: Extend BDW late-loading with a revision check")
Signed-off-by: Jia Zhang 
Signed-off-by: Borislav Petkov 
Signed-off-by: Thomas Gleixner 
Acked-by: Tony Luck 
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1516321542-31161-1-git-send-email-zhang.jia@linux.alibaba.com