linux-stable.git/arch, branch v4.4.219

KVM: VMX: Do not allow reexecute_instruction() when skipping MMIO instr

2020-04-02T17:02:34+00:00

[ Upstream commit c4409905cd6eb42cfd06126e9226b0150e05a715 ]

Re-execution after an emulation decode failure is only intended to
handle a case where two or vCPUs race to write a shadowed page, i.e.
we should never re-execute an instruction as part of MMIO emulation.
As handle_ept_misconfig() is only used for MMIO emulation, it should
pass EMULTYPE_NO_REEXECUTE when using the emulator to skip an instr
in the fast-MMIO case where VM_EXIT_INSTRUCTION_LEN is invalid.

And because the cr2 value passed to x86_emulate_instruction() is only
destined for use when retrying or reexecuting, we can simply call
emulate_instruction().

Fixes: d391f1207067 ("x86/kvm/vmx: do not use vm-exit instruction length
                      for fast MMIO when running nested")
Cc: Vitaly Kuznetsov 
Signed-off-by: Sean Christopherson 
Cc: stable@vger.kernel.org
Signed-off-by: Radim Krčmář 
Signed-off-by: Sasha Levin

arm64: smp: fix smp_send_stop() behaviour

2020-04-02T17:02:32+00:00

commit d0bab0c39e32d39a8c5cddca72e5b4a3059fe050 upstream.

On a system with only one CPU online, when another one CPU panics while
starting-up, smp_send_stop() will fail to send any STOP message to the
other already online core, resulting in a system still responsive and
alive at the end of the panic procedure.

[  186.700083] CPU3: shutdown
[  187.075462] CPU2: shutdown
[  187.162869] CPU1: shutdown
[  188.689998] ------------[ cut here ]------------
[  188.691645] kernel BUG at arch/arm64/kernel/cpufeature.c:886!
[  188.692079] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
[  188.692444] Modules linked in:
[  188.693031] CPU: 3 PID: 0 Comm: swapper/3 Not tainted 5.6.0-rc4-00001-g338d25c35a98 #104
[  188.693175] Hardware name: Foundation-v8A (DT)
[  188.693492] pstate: 200001c5 (nzCv dAIF -PAN -UAO)
[  188.694183] pc : has_cpuid_feature+0xf0/0x348
[  188.694311] lr : verify_local_elf_hwcaps+0x84/0xe8
[  188.694410] sp : ffff800011b1bf60
[  188.694536] x29: ffff800011b1bf60 x28: 0000000000000000
[  188.694707] x27: 0000000000000000 x26: 0000000000000000
[  188.694801] x25: 0000000000000000 x24: ffff80001189a25c
[  188.694905] x23: 0000000000000000 x22: 0000000000000000
[  188.694996] x21: ffff8000114aa018 x20: ffff800011156a38
[  188.695089] x19: ffff800010c944a0 x18: 0000000000000004
[  188.695187] x17: 0000000000000000 x16: 0000000000000000
[  188.695280] x15: 0000249dbde5431e x14: 0262cbe497efa1fa
[  188.695371] x13: 0000000000000002 x12: 0000000000002592
[  188.695472] x11: 0000000000000080 x10: 00400032b5503510
[  188.695572] x9 : 0000000000000000 x8 : ffff800010c80204
[  188.695659] x7 : 00000000410fd0f0 x6 : 0000000000000001
[  188.695750] x5 : 00000000410fd0f0 x4 : 0000000000000000
[  188.695836] x3 : 0000000000000000 x2 : ffff8000100939d8
[  188.695919] x1 : 0000000000180420 x0 : 0000000000180480
[  188.696253] Call trace:
[  188.696410]  has_cpuid_feature+0xf0/0x348
[  188.696504]  verify_local_elf_hwcaps+0x84/0xe8
[  188.696591]  check_local_cpu_capabilities+0x44/0x128
[  188.696666]  secondary_start_kernel+0xf4/0x188
[  188.697150] Code: 52805001 72a00301 6b01001f 54000ec0 (d4210000)
[  188.698639] ---[ end trace 3f12ca47652f7b72 ]---
[  188.699160] Kernel panic - not syncing: Attempted to kill the idle task!
[  188.699546] Kernel Offset: disabled
[  188.699828] CPU features: 0x00004,20c02008
[  188.700012] Memory Limit: none
[  188.700538] ---[ end Kernel panic - not syncing: Attempted to kill the idle task! ]---

[root@arch ~]# echo Helo
Helo
[root@arch ~]# cat /proc/cpuinfo | grep proce
processor	: 0

Make smp_send_stop() account also for the online status of the calling CPU
while evaluating how many CPUs are effectively online: this way, the right
number of STOPs is sent, so enforcing a proper freeze of the system at the
end of panic even under the above conditions.

Fixes: 08e875c16a16c ("arm64: SMP support")
Reported-by: Dave Martin 
Acked-by: Mark Rutland 
Signed-off-by: Cristian Marussi 
Signed-off-by: Will Deacon 
Signed-off-by: Greg Kroah-Hartman

x86/mm: split vmalloc_sync_all()

2020-04-02T17:02:31+00:00

commit 763802b53a427ed3cbd419dbba255c414fdd9e7c upstream.

Commit 3f8fd02b1bf1 ("mm/vmalloc: Sync unmappings in
__purge_vmap_area_lazy()") introduced a call to vmalloc_sync_all() in
the vunmap() code-path.  While this change was necessary to maintain
correctness on x86-32-pae kernels, it also adds additional cycles for
architectures that don't need it.

Specifically on x86-64 with CONFIG_VMAP_STACK=y some people reported
severe performance regressions in micro-benchmarks because it now also
calls the x86-64 implementation of vmalloc_sync_all() on vunmap().  But
the vmalloc_sync_all() implementation on x86-64 is only needed for newly
created mappings.

To avoid the unnecessary work on x86-64 and to gain the performance
back, split up vmalloc_sync_all() into two functions:

	* vmalloc_sync_mappings(), and
	* vmalloc_sync_unmappings()

Most call-sites to vmalloc_sync_all() only care about new mappings being
synchronized.  The only exception is the new call-site added in the
above mentioned commit.

Shile Zhang directed us to a report of an 80% regression in reaim
throughput.

Fixes: 3f8fd02b1bf1 ("mm/vmalloc: Sync unmappings in __purge_vmap_area_lazy()")
Reported-by: kernel test robot 
Reported-by: Shile Zhang 
Signed-off-by: Joerg Roedel 
Signed-off-by: Andrew Morton 
Tested-by: Borislav Petkov 
Acked-by: Rafael J. Wysocki 	[GHES]
Cc: Dave Hansen 
Cc: Andy Lutomirski 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: 
Link: http://lkml.kernel.org/r/20191009124418.8286-1-joro@8bytes.org
Link: https://lists.01.org/hyperkitty/list/lkp@lists.01.org/thread/4D3JPPHBNOSPFK2KEPC6KGKS6J25AIDB/
Link: http://lkml.kernel.org/r/20191113095530.228959-1-shile.zhang@linux.alibaba.com
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

ARM: dts: dra7: Add "dma-ranges" property to PCIe RC DT nodes

2020-04-02T17:02:28+00:00

[ Upstream commit 27f13774654ea6bd0b6fc9b97cce8d19e5735661 ]

'dma-ranges' in a PCI bridge node does correctly set dma masks for PCI
devices not described in the DT. Certain DRA7 platforms (e.g., DRA76)
has RAM above 32-bit boundary (accessible with LPAE config) though the
PCIe bridge will be able to access only 32-bits. Add 'dma-ranges'
property in PCIe RC DT nodes to indicate the host bridge can access
only 32 bits.

Signed-off-by: Kishon Vijay Abraham I 
Signed-off-by: Tony Lindgren 
Signed-off-by: Sasha Levin

powerpc: Include .BTF section

2020-04-02T17:02:27+00:00

[ Upstream commit cb0cc635c7a9fa8a3a0f75d4d896721819c63add ]

Selecting CONFIG_DEBUG_INFO_BTF results in the below warning from ld:
  ld: warning: orphan section `.BTF' from `.btf.vmlinux.bin.o' being placed in section `.BTF'

Include .BTF section in vmlinux explicitly to fix the same.

Signed-off-by: Naveen N. Rao 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20200220113132.857132-1-naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Sasha Levin

ARM: 8958/1: rename missed uaccess .fixup section

2020-03-20T08:06:34+00:00

commit f87b1c49bc675da30d8e1e8f4b60b800312c7b90 upstream.

When the uaccess .fixup section was renamed to .text.fixup, one case was
missed. Under ld.bfd, the orphaned section was moved close to .text
(since they share the "ax" bits), so things would work normally on
uaccess faults. Under ld.lld, the orphaned section was placed outside
the .text section, making it unreachable.

Link: https://github.com/ClangBuiltLinux/linux/issues/282
Link: https://bugs.chromium.org/p/chromium/issues/detail?id=1020633#c44
Link: https://lore.kernel.org/r/nycvar.YSQ.7.76.1912032147340.17114@knanqh.ubzr
Link: https://lore.kernel.org/lkml/202002071754.F5F073F1D@keescook/

Fixes: c4a84ae39b4a5 ("ARM: 8322/1: keep .text and .fixup regions closer together")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook 
Reviewed-by: Ard Biesheuvel 
Reviewed-by: Nick Desaulniers 
Signed-off-by: Russell King 
Signed-off-by: Greg Kroah-Hartman

ARM: 8957/1: VDSO: Match ARMv8 timer in cntvct_functional()

2020-03-20T08:06:34+00:00

commit 45939ce292b4b11159719faaf60aba7d58d5fe33 upstream.

It is possible for a system with an ARMv8 timer to run a 32-bit kernel.
When this happens we will unconditionally have the vDSO code remove the
__vdso_gettimeofday and __vdso_clock_gettime symbols because
cntvct_functional() returns false since it does not match that
compatibility string.

Fixes: ecf99a439105 ("ARM: 8331/1: VDSO initialization, mapping, and synchronization")
Signed-off-by: Florian Fainelli 
Signed-off-by: Russell King 
Signed-off-by: Greg Kroah-Hartman

perf/amd/uncore: Replace manual sampling check with CAP_NO_INTERRUPT flag

2020-03-20T08:06:33+00:00

[ Upstream commit f967140dfb7442e2db0868b03b961f9c59418a1b ]

Enable the sampling check in kernel/events/core.c::perf_event_open(),
which returns the more appropriate -EOPNOTSUPP.

BEFORE:

  $ sudo perf record -a -e instructions,l3_request_g1.caching_l3_cache_accesses true
  Error:
  The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (l3_request_g1.caching_l3_cache_accesses).
  /bin/dmesg | grep -i perf may provide additional information.

With nothing relevant in dmesg.

AFTER:

  $ sudo perf record -a -e instructions,l3_request_g1.caching_l3_cache_accesses true
  Error:
  l3_request_g1.caching_l3_cache_accesses: PMU Hardware doesn't support sampling/overflow-interrupts. Try 'perf stat'

Fixes: c43ca5091a37 ("perf/x86/amd: Add support for AMD NB and L2I "uncore" counters")
Signed-off-by: Kim Phillips 
Signed-off-by: Borislav Petkov 
Acked-by: Peter Zijlstra 
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20200311191323.13124-1-kim.phillips@amd.com
Signed-off-by: Sasha Levin

ARC: define __ALIGN_STR and __ALIGN symbols for ARC

2020-03-20T08:06:22+00:00

commit 8d92e992a785f35d23f845206cf8c6cafbc264e0 upstream.

The default defintions use fill pattern 0x90 for padding which for ARC
generates unintended "ldh_s r12,[r0,0x20]" corresponding to opcode 0x9090

So use ".align 4" which insert a "nop_s" instruction instead.

Cc: stable@vger.kernel.org
Acked-by: Vineet Gupta 
Signed-off-by: Eugeniy Paltsev 
Signed-off-by: Vineet Gupta 
Signed-off-by: Greg Kroah-Hartman

KVM: x86: clear stale x86_emulate_ctxt->intercept value

2020-03-20T08:06:22+00:00

commit 342993f96ab24d5864ab1216f46c0b199c2baf8e upstream.

After commit 07721feee46b ("KVM: nVMX: Don't emulate instructions in guest
mode") Hyper-V guests on KVM stopped booting with:

 kvm_nested_vmexit:    rip fffff802987d6169 reason EPT_VIOLATION info1 181
    info2 0 int_info 0 int_info_err 0
 kvm_page_fault:       address febd0000 error_code 181
 kvm_emulate_insn:     0:fffff802987d6169: f3 a5
 kvm_emulate_insn:     0:fffff802987d6169: f3 a5 FAIL
 kvm_inj_exception:    #UD (0x0)

"f3 a5" is a "rep movsw" instruction, which should not be intercepted
at all.  Commit c44b4c6ab80e ("KVM: emulate: clean up initializations in
init_decode_cache") reduced the number of fields cleared by
init_decode_cache() claiming that they are being cleared elsewhere,
'intercept', however, is left uncleared if the instruction does not have
any of the "slow path" flags (NotImpl, Stack, Op3264, Sse, Mmx, CheckPerm,
NearBranch, No16 and of course Intercept itself).

Fixes: c44b4c6ab80e ("KVM: emulate: clean up initializations in init_decode_cache")
Fixes: 07721feee46b ("KVM: nVMX: Don't emulate instructions in guest mode")
Cc: stable@vger.kernel.org
Suggested-by: Paolo Bonzini 
Signed-off-by: Vitaly Kuznetsov 
Reviewed-by: Sean Christopherson 
Signed-off-by: Paolo Bonzini 
Signed-off-by: Greg Kroah-Hartman