linux-stable.git/arch/powerpc/kernel, branch v4.4.25 Linux kernel stable tree powerpc/prom: Fix sub-processor option passed to ibm, client-architecture-support 2016-10-07T13:23:46+00:00 Michael Ellerman mpe@ellerman.id.au 2016-08-12T11:45:52+00:00 bef613a0bef4f45c2b73f3fddbe1f08938e0e08a commit 66443efa83dc73775100b7442962ce2cb0d4472e upstream. When booting from an OpenFirmware which supports it, we use the "ibm,client-architecture-support" firmware call to communicate our capabilities to firmware. The format of the structure we pass to firmware is specified in PAPR (Power Architecture Platform Requirements), or the public version LoPAPR (Linux on Power Architecture Platform Reference). Referring to table 244 in LoPAPR v1.1, option vector 5 contains a 4 byte field at bytes 17-20 for the "Platform Facilities Enable". This is followed by a 1 byte field at byte 21 for "Sub-Processor Represenation Level". Comparing to the code, there we have the Platform Facilities options (OV5_PFO_*) at byte 17, but we fail to pad that field out to its full width of 4 bytes. This means the OV5_SUB_PROCESSORS option is incorrectly placed at byte 18. Fix it by adding zero bytes for bytes 18, 19, 20, and comment the bytes to hopefully make it clearer in future. As far as I'm aware nothing actually consumes this value at this time, so the effect of this bug is nil in practice. It does mean we've been incorrectly setting bit 15 of the "Platform Facilities Enable" option for the past ~3 1/2 years, so we should avoid allocating that bit to anything else in future. Fixes: df77c7992029 ("powerpc/pseries: Update ibm,architecture.vec for PAPR 2.7/POWER8") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 66443efa83dc73775100b7442962ce2cb0d4472e upstream.

When booting from an OpenFirmware which supports it, we use the
"ibm,client-architecture-support" firmware call to communicate
our capabilities to firmware.

The format of the structure we pass to firmware is specified in
PAPR (Power Architecture Platform Requirements), or the public version
LoPAPR (Linux on Power Architecture Platform Reference).

Referring to table 244 in LoPAPR v1.1, option vector 5 contains a 4 byte
field at bytes 17-20 for the "Platform Facilities Enable". This is
followed by a 1 byte field at byte 21 for "Sub-Processor Represenation
Level".

Comparing to the code, there we have the Platform Facilities
options (OV5_PFO_*) at byte 17, but we fail to pad that field out to its
full width of 4 bytes. This means the OV5_SUB_PROCESSORS option is
incorrectly placed at byte 18.

Fix it by adding zero bytes for bytes 18, 19, 20, and comment the bytes
to hopefully make it clearer in future.

As far as I'm aware nothing actually consumes this value at this time,
so the effect of this bug is nil in practice.

It does mean we've been incorrectly setting bit 15 of the "Platform
Facilities Enable" option for the past ~3 1/2 years, so we should avoid
allocating that bit to anything else in future.

Fixes: df77c7992029 ("powerpc/pseries: Update ibm,architecture.vec for PAPR 2.7/POWER8")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
powerpc/tm: do not use r13 for tabort_syscall 2016-09-24T08:07:35+00:00 Nicholas Piggin npiggin@gmail.com 2016-07-25T04:26:51+00:00 53545131ecea3a41f4b1b4f6d8b04c8a2a78ac35 commit cc7786d3ee7e3c979799db834b528db2c0834c2e upstream. tabort_syscall runs with RI=1, so a nested recoverable machine check will load the paca into r13 and overwrite what we loaded it with, because exceptions returning to privileged mode do not restore r13. Fixes: b4b56f9ecab4 (powerpc/tm: Abort syscalls in active transactions) Signed-off-by: Nick Piggin <npiggin@gmail.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit cc7786d3ee7e3c979799db834b528db2c0834c2e upstream.

tabort_syscall runs with RI=1, so a nested recoverable machine
check will load the paca into r13 and overwrite what we loaded
it with, because exceptions returning to privileged mode do not
restore r13.

Fixes: b4b56f9ecab4 (powerpc/tm: Abort syscalls in active transactions)
Signed-off-by: Nick Piggin <npiggin@gmail.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
powerpc/tm: Avoid SLB faults in treclaim/trecheckpoint when RI=0 2016-09-15T06:27:51+00:00 Michael Neuling mikey@neuling.org 2016-06-28T03:01:04+00:00 0e324f6d66549b6a98122f2bd8da5ae56b018956 commit 190ce8693c23eae09ba5f303a83bf2fbeb6478b1 upstream. Currently we have 2 segments that are bolted for the kernel linear mapping (ie 0xc000... addresses). This is 0 to 1TB and also the kernel stacks. Anything accessed outside of these regions may need to be faulted in. (In practice machines with TM always have 1T segments) If a machine has < 2TB of memory we never fault on the kernel linear mapping as these two segments cover all physical memory. If a machine has > 2TB of memory, there may be structures outside of these two segments that need to be faulted in. This faulting can occur when running as a guest as the hypervisor may remove any SLB that's not bolted. When we treclaim and trecheckpoint we have a window where we need to run with the userspace GPRs. This means that we no longer have a valid stack pointer in r1. For this window we therefore clear MSR RI to indicate that any exceptions taken at this point won't be able to be handled. This means that we can't take segment misses in this RI=0 window. In this RI=0 region, we currently access the thread_struct for the process being context switched to or from. This thread_struct access may cause a segment fault since it's not guaranteed to be covered by the two bolted segment entries described above. We've seen this with a crash when running as a guest with > 2TB of memory on PowerVM: Unrecoverable exception 4100 at c00000000004f138 Oops: Unrecoverable exception, sig: 6 [#1] SMP NR_CPUS=2048 NUMA pSeries CPU: 1280 PID: 7755 Comm: kworker/1280:1 Tainted: G X 4.4.13-46-default #1 task: c000189001df4210 ti: c000189001d5c000 task.ti: c000189001d5c000 NIP: c00000000004f138 LR: 0000000010003a24 CTR: 0000000010001b20 REGS: c000189001d5f730 TRAP: 4100 Tainted: G X (4.4.13-46-default) MSR: 8000000100001031 <SF,ME,IR,DR,LE> CR: 24000048 XER: 00000000 CFAR: c00000000004ed18 SOFTE: 0 GPR00: ffffffffc58d7b60 c000189001d5f9b0 00000000100d7d00 000000003a738288 GPR04: 0000000000002781 0000000000000006 0000000000000000 c0000d1f4d889620 GPR08: 000000000000c350 00000000000008ab 00000000000008ab 00000000100d7af0 GPR12: 00000000100d7ae8 00003ffe787e67a0 0000000000000000 0000000000000211 GPR16: 0000000010001b20 0000000000000000 0000000000800000 00003ffe787df110 GPR20: 0000000000000001 00000000100d1e10 0000000000000000 00003ffe787df050 GPR24: 0000000000000003 0000000000010000 0000000000000000 00003fffe79e2e30 GPR28: 00003fffe79e2e68 00000000003d0f00 00003ffe787e67a0 00003ffe787de680 NIP [c00000000004f138] restore_gprs+0xd0/0x16c LR [0000000010003a24] 0x10003a24 Call Trace: [c000189001d5f9b0] [c000189001d5f9f0] 0xc000189001d5f9f0 (unreliable) [c000189001d5fb90] [c00000000001583c] tm_recheckpoint+0x6c/0xa0 [c000189001d5fbd0] [c000000000015c40] __switch_to+0x2c0/0x350 [c000189001d5fc30] [c0000000007e647c] __schedule+0x32c/0x9c0 [c000189001d5fcb0] [c0000000007e6b58] schedule+0x48/0xc0 [c000189001d5fce0] [c0000000000deabc] worker_thread+0x22c/0x5b0 [c000189001d5fd80] [c0000000000e7000] kthread+0x110/0x130 [c000189001d5fe30] [c000000000009538] ret_from_kernel_thread+0x5c/0xa4 Instruction dump: 7cb103a6 7cc0e3a6 7ca222a6 78a58402 38c00800 7cc62838 08860000 7cc000a6 38a00006 78c60022 7cc62838 0b060000 <e8c701a0> 7ccff120 e8270078 e8a70098 ---[ end trace 602126d0a1dedd54 ]--- This fixes this by copying the required data from the thread_struct to the stack before we clear MSR RI. Then once we clear RI, we only access the stack, guaranteeing there's no segment miss. We also tighten the region over which we set RI=0 on the treclaim() path. This may have a slight performance impact since we're adding an mtmsr instruction. Fixes: 090b9284d725 ("powerpc/tm: Clear MSR RI in non-recoverable TM code") Signed-off-by: Michael Neuling <mikey@neuling.org> Reviewed-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 190ce8693c23eae09ba5f303a83bf2fbeb6478b1 upstream.

Currently we have 2 segments that are bolted for the kernel linear
mapping (ie 0xc000... addresses). This is 0 to 1TB and also the kernel
stacks. Anything accessed outside of these regions may need to be
faulted in. (In practice machines with TM always have 1T segments)

If a machine has < 2TB of memory we never fault on the kernel linear
mapping as these two segments cover all physical memory. If a machine
has > 2TB of memory, there may be structures outside of these two
segments that need to be faulted in. This faulting can occur when
running as a guest as the hypervisor may remove any SLB that's not
bolted.

When we treclaim and trecheckpoint we have a window where we need to
run with the userspace GPRs. This means that we no longer have a valid
stack pointer in r1. For this window we therefore clear MSR RI to
indicate that any exceptions taken at this point won't be able to be
handled. This means that we can't take segment misses in this RI=0
window.

In this RI=0 region, we currently access the thread_struct for the
process being context switched to or from. This thread_struct access
may cause a segment fault since it's not guaranteed to be covered by
the two bolted segment entries described above.

We've seen this with a crash when running as a guest with > 2TB of
memory on PowerVM:

  Unrecoverable exception 4100 at c00000000004f138
  Oops: Unrecoverable exception, sig: 6 [#1]
  SMP NR_CPUS=2048 NUMA pSeries
  CPU: 1280 PID: 7755 Comm: kworker/1280:1 Tainted: G                 X 4.4.13-46-default #1
  task: c000189001df4210 ti: c000189001d5c000 task.ti: c000189001d5c000
  NIP: c00000000004f138 LR: 0000000010003a24 CTR: 0000000010001b20
  REGS: c000189001d5f730 TRAP: 4100   Tainted: G                 X  (4.4.13-46-default)
  MSR: 8000000100001031 <SF,ME,IR,DR,LE>  CR: 24000048  XER: 00000000
  CFAR: c00000000004ed18 SOFTE: 0
  GPR00: ffffffffc58d7b60 c000189001d5f9b0 00000000100d7d00 000000003a738288
  GPR04: 0000000000002781 0000000000000006 0000000000000000 c0000d1f4d889620
  GPR08: 000000000000c350 00000000000008ab 00000000000008ab 00000000100d7af0
  GPR12: 00000000100d7ae8 00003ffe787e67a0 0000000000000000 0000000000000211
  GPR16: 0000000010001b20 0000000000000000 0000000000800000 00003ffe787df110
  GPR20: 0000000000000001 00000000100d1e10 0000000000000000 00003ffe787df050
  GPR24: 0000000000000003 0000000000010000 0000000000000000 00003fffe79e2e30
  GPR28: 00003fffe79e2e68 00000000003d0f00 00003ffe787e67a0 00003ffe787de680
  NIP [c00000000004f138] restore_gprs+0xd0/0x16c
  LR [0000000010003a24] 0x10003a24
  Call Trace:
  [c000189001d5f9b0] [c000189001d5f9f0] 0xc000189001d5f9f0 (unreliable)
  [c000189001d5fb90] [c00000000001583c] tm_recheckpoint+0x6c/0xa0
  [c000189001d5fbd0] [c000000000015c40] __switch_to+0x2c0/0x350
  [c000189001d5fc30] [c0000000007e647c] __schedule+0x32c/0x9c0
  [c000189001d5fcb0] [c0000000007e6b58] schedule+0x48/0xc0
  [c000189001d5fce0] [c0000000000deabc] worker_thread+0x22c/0x5b0
  [c000189001d5fd80] [c0000000000e7000] kthread+0x110/0x130
  [c000189001d5fe30] [c000000000009538] ret_from_kernel_thread+0x5c/0xa4
  Instruction dump:
  7cb103a6 7cc0e3a6 7ca222a6 78a58402 38c00800 7cc62838 08860000 7cc000a6
  38a00006 78c60022 7cc62838 0b060000 <e8c701a0> 7ccff120 e8270078 e8a70098
  ---[ end trace 602126d0a1dedd54 ]---

This fixes this by copying the required data from the thread_struct to
the stack before we clear MSR RI. Then once we clear RI, we only access
the stack, guaranteeing there's no segment miss.

We also tighten the region over which we set RI=0 on the treclaim()
path. This may have a slight performance impact since we're adding an
mtmsr instruction.

Fixes: 090b9284d725 ("powerpc/tm: Clear MSR RI in non-recoverable TM code")
Signed-off-by: Michael Neuling <mikey@neuling.org>
Reviewed-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
powerpc/eeh: eeh_pci_enable(): fix checking of post-request state 2016-09-07T06:32:36+00:00 Andrew Donnellan andrew.donnellan@au1.ibm.com 2015-10-23T06:19:46+00:00 93ed332bd4105e8af3e12e12fa510728147badfc commit 949e9b827eb4736d96df520c67d07a54c64e99b8 upstream. In eeh_pci_enable(), after making the request to set the new options, we call eeh_ops->wait_state() to check that the request finished successfully. At the moment, if eeh_ops->wait_state() returns 0, we return 0 without checking that it reflects the expected outcome. This can lead to callers further up the chain incorrectly assuming the slot has been successfully unfrozen and continuing to attempt recovery. On powernv, this will occur if pnv_eeh_get_pe_state() or pnv_eeh_get_phb_state() return 0, which in turn occurs if the relevant OPAL call returns OPAL_EEH_STOPPED_MMIO_DMA_FREEZE or OPAL_EEH_PHB_ERROR respectively. On pseries, this will occur if pseries_eeh_get_state() returns 0, which in turn occurs if RTAS reports that the PE is in the MMIO Stopped and DMA Stopped states. Obviously, none of these cases represent a successful completion of a request to thaw MMIO or DMA. Fix the check so that a wait_state() return value of 0 won't be considered successful for the EEH_OPT_THAW_MMIO or EEH_OPT_THAW_DMA cases. Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Acked-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Reviewed-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 949e9b827eb4736d96df520c67d07a54c64e99b8 upstream.

In eeh_pci_enable(), after making the request to set the new options, we
call eeh_ops->wait_state() to check that the request finished successfully.

At the moment, if eeh_ops->wait_state() returns 0, we return 0 without
checking that it reflects the expected outcome. This can lead to callers
further up the chain incorrectly assuming the slot has been successfully
unfrozen and continuing to attempt recovery.

On powernv, this will occur if pnv_eeh_get_pe_state() or
pnv_eeh_get_phb_state() return 0, which in turn occurs if the relevant OPAL
call returns OPAL_EEH_STOPPED_MMIO_DMA_FREEZE or
OPAL_EEH_PHB_ERROR respectively.

On pseries, this will occur if pseries_eeh_get_state() returns 0, which in
turn occurs if RTAS reports that the PE is in the MMIO Stopped and DMA
Stopped states.

Obviously, none of these cases represent a successful completion of a
request to thaw MMIO or DMA.

Fix the check so that a wait_state() return value of 0 won't be considered
successful for the EEH_OPT_THAW_MMIO or EEH_OPT_THAW_DMA cases.

Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Reviewed-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
powerpc/tm: Always reclaim in start_thread() for exec() class syscalls 2016-07-27T16:47:28+00:00 Cyril Bur cyrilbur@gmail.com 2016-06-17T04:58:34+00:00 5a35d2f92f1011145315f86a481f4f3e3f853095 commit 8e96a87c5431c256feb65bcfc5aec92d9f7839b6 upstream. Userspace can quite legitimately perform an exec() syscall with a suspended transaction. exec() does not return to the old process, rather it load a new one and starts that, the expectation therefore is that the new process starts not in a transaction. Currently exec() is not treated any differently to any other syscall which creates problems. Firstly it could allow a new process to start with a suspended transaction for a binary that no longer exists. This means that the checkpointed state won't be valid and if the suspended transaction were ever to be resumed and subsequently aborted (a possibility which is exceedingly likely as exec()ing will likely doom the transaction) the new process will jump to invalid state. Secondly the incorrect attempt to keep the transactional state while still zeroing state for the new process creates at least two TM Bad Things. The first triggers on the rfid to return to userspace as start_thread() has given the new process a 'clean' MSR but the suspend will still be set in the hardware MSR. The second TM Bad Thing triggers in __switch_to() as the processor is still transactionally suspended but __switch_to() wants to zero the TM sprs for the new process. This is an example of the outcome of calling exec() with a suspended transaction. Note the first 700 is likely the first TM bad thing decsribed earlier only the kernel can't report it as we've loaded userspace registers. c000000000009980 is the rfid in fast_exception_return() Bad kernel stack pointer 3fffcfa1a370 at c000000000009980 Oops: Bad kernel stack pointer, sig: 6 [#1] CPU: 0 PID: 2006 Comm: tm-execed Not tainted NIP: c000000000009980 LR: 0000000000000000 CTR: 0000000000000000 REGS: c00000003ffefd40 TRAP: 0700 Not tainted MSR: 8000000300201031 <SF,ME,IR,DR,LE,TM[SE]> CR: 00000000 XER: 00000000 CFAR: c0000000000098b4 SOFTE: 0 PACATMSCRATCH: b00000010000d033 GPR00: 0000000000000000 00003fffcfa1a370 0000000000000000 0000000000000000 GPR04: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR08: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR12: 00003fff966611c0 0000000000000000 0000000000000000 0000000000000000 NIP [c000000000009980] fast_exception_return+0xb0/0xb8 LR [0000000000000000] (null) Call Trace: Instruction dump: f84d0278 e9a100d8 7c7b03a6 e84101a0 7c4ff120 e8410170 7c5a03a6 e8010070 e8410080 e8610088 e8810090 e8210078 <4c000024> 48000000 e8610178 88ed023b Kernel BUG at c000000000043e80 [verbose debug info unavailable] Unexpected TM Bad Thing exception at c000000000043e80 (msr 0x201033) Oops: Unrecoverable exception, sig: 6 [#2] CPU: 0 PID: 2006 Comm: tm-execed Tainted: G D task: c0000000fbea6d80 ti: c00000003ffec000 task.ti: c0000000fb7ec000 NIP: c000000000043e80 LR: c000000000015a24 CTR: 0000000000000000 REGS: c00000003ffef7e0 TRAP: 0700 Tainted: G D MSR: 8000000300201033 <SF,ME,IR,DR,RI,LE,TM[SE]> CR: 28002828 XER: 00000000 CFAR: c000000000015a20 SOFTE: 0 PACATMSCRATCH: b00000010000d033 GPR00: 0000000000000000 c00000003ffefa60 c000000000db5500 c0000000fbead000 GPR04: 8000000300001033 2222222222222222 2222222222222222 00000000ff160000 GPR08: 0000000000000000 800000010000d033 c0000000fb7e3ea0 c00000000fe00004 GPR12: 0000000000002200 c00000000fe00000 0000000000000000 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR20: 0000000000000000 0000000000000000 c0000000fbea7410 00000000ff160000 GPR24: c0000000ffe1f600 c0000000fbea8700 c0000000fbea8700 c0000000fbead000 GPR28: c000000000e20198 c0000000fbea6d80 c0000000fbeab680 c0000000fbea6d80 NIP [c000000000043e80] tm_restore_sprs+0xc/0x1c LR [c000000000015a24] __switch_to+0x1f4/0x420 Call Trace: Instruction dump: 7c800164 4e800020 7c0022a6 f80304a8 7c0222a6 f80304b0 7c0122a6 f80304b8 4e800020 e80304a8 7c0023a6 e80304b0 <7c0223a6> e80304b8 7c0123a6 4e800020 This fixes CVE-2016-5828. Fixes: bc2a9408fa65 ("powerpc: Hook in new transactional memory code") Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 8e96a87c5431c256feb65bcfc5aec92d9f7839b6 upstream.

Userspace can quite legitimately perform an exec() syscall with a
suspended transaction. exec() does not return to the old process, rather
it load a new one and starts that, the expectation therefore is that the
new process starts not in a transaction. Currently exec() is not treated
any differently to any other syscall which creates problems.

Firstly it could allow a new process to start with a suspended
transaction for a binary that no longer exists. This means that the
checkpointed state won't be valid and if the suspended transaction were
ever to be resumed and subsequently aborted (a possibility which is
exceedingly likely as exec()ing will likely doom the transaction) the
new process will jump to invalid state.

Secondly the incorrect attempt to keep the transactional state while
still zeroing state for the new process creates at least two TM Bad
Things. The first triggers on the rfid to return to userspace as
start_thread() has given the new process a 'clean' MSR but the suspend
will still be set in the hardware MSR. The second TM Bad Thing triggers
in __switch_to() as the processor is still transactionally suspended but
__switch_to() wants to zero the TM sprs for the new process.

This is an example of the outcome of calling exec() with a suspended
transaction. Note the first 700 is likely the first TM bad thing
decsribed earlier only the kernel can't report it as we've loaded
userspace registers. c000000000009980 is the rfid in
fast_exception_return()

  Bad kernel stack pointer 3fffcfa1a370 at c000000000009980
  Oops: Bad kernel stack pointer, sig: 6 [#1]
  CPU: 0 PID: 2006 Comm: tm-execed Not tainted
  NIP: c000000000009980 LR: 0000000000000000 CTR: 0000000000000000
  REGS: c00000003ffefd40 TRAP: 0700   Not tainted
  MSR: 8000000300201031 <SF,ME,IR,DR,LE,TM[SE]>  CR: 00000000  XER: 00000000
  CFAR: c0000000000098b4 SOFTE: 0
  PACATMSCRATCH: b00000010000d033
  GPR00: 0000000000000000 00003fffcfa1a370 0000000000000000 0000000000000000
  GPR04: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR08: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR12: 00003fff966611c0 0000000000000000 0000000000000000 0000000000000000
  NIP [c000000000009980] fast_exception_return+0xb0/0xb8
  LR [0000000000000000]           (null)
  Call Trace:
  Instruction dump:
  f84d0278 e9a100d8 7c7b03a6 e84101a0 7c4ff120 e8410170 7c5a03a6 e8010070
  e8410080 e8610088 e8810090 e8210078 <4c000024> 48000000 e8610178 88ed023b

  Kernel BUG at c000000000043e80 [verbose debug info unavailable]
  Unexpected TM Bad Thing exception at c000000000043e80 (msr 0x201033)
  Oops: Unrecoverable exception, sig: 6 [#2]
  CPU: 0 PID: 2006 Comm: tm-execed Tainted: G      D
  task: c0000000fbea6d80 ti: c00000003ffec000 task.ti: c0000000fb7ec000
  NIP: c000000000043e80 LR: c000000000015a24 CTR: 0000000000000000
  REGS: c00000003ffef7e0 TRAP: 0700   Tainted: G      D
  MSR: 8000000300201033 <SF,ME,IR,DR,RI,LE,TM[SE]>  CR: 28002828  XER: 00000000
  CFAR: c000000000015a20 SOFTE: 0
  PACATMSCRATCH: b00000010000d033
  GPR00: 0000000000000000 c00000003ffefa60 c000000000db5500 c0000000fbead000
  GPR04: 8000000300001033 2222222222222222 2222222222222222 00000000ff160000
  GPR08: 0000000000000000 800000010000d033 c0000000fb7e3ea0 c00000000fe00004
  GPR12: 0000000000002200 c00000000fe00000 0000000000000000 0000000000000000
  GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR20: 0000000000000000 0000000000000000 c0000000fbea7410 00000000ff160000
  GPR24: c0000000ffe1f600 c0000000fbea8700 c0000000fbea8700 c0000000fbead000
  GPR28: c000000000e20198 c0000000fbea6d80 c0000000fbeab680 c0000000fbea6d80
  NIP [c000000000043e80] tm_restore_sprs+0xc/0x1c
  LR [c000000000015a24] __switch_to+0x1f4/0x420
  Call Trace:
  Instruction dump:
  7c800164 4e800020 7c0022a6 f80304a8 7c0222a6 f80304b0 7c0122a6 f80304b8
  4e800020 e80304a8 7c0023a6 e80304b0 <7c0223a6> e80304b8 7c0123a6 4e800020

This fixes CVE-2016-5828.

Fixes: bc2a9408fa65 ("powerpc: Hook in new transactional memory code")
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
powerpc/pseries: Fix IBM_ARCH_VEC_NRCORES_OFFSET since POWER8NVL was added 2016-07-27T16:47:28+00:00 Michael Ellerman mpe@ellerman.id.au 2016-06-08T00:01:23+00:00 044af1b034a0cbea5dea8d9d0f4a5c66968edd10 commit 2c2a63e301fd19ccae673e79de59b30a232ff7f9 upstream. The recent commit 7cc851039d64 ("powerpc/pseries: Add POWER8NVL support to ibm,client-architecture-support call") added a new PVR mask & value to the start of the ibm_architecture_vec[] array. However it missed the fact that further down in the array, we hard code the offset of one of the fields, and then at boot use that value to patch the value in the array. This means every update to the array must also update the #define, ugh. This means that on pseries machines we will misreport to firmware the number of cores we support, by a factor of threads_per_core. Fix it for now by updating the #define. Fixes: 7cc851039d64 ("powerpc/pseries: Add POWER8NVL support to ibm,client-architecture-support call") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 2c2a63e301fd19ccae673e79de59b30a232ff7f9 upstream.

The recent commit 7cc851039d64 ("powerpc/pseries: Add POWER8NVL support
to ibm,client-architecture-support call") added a new PVR mask & value
to the start of the ibm_architecture_vec[] array.

However it missed the fact that further down in the array, we hard code
the offset of one of the fields, and then at boot use that value to
patch the value in the array. This means every update to the array must
also update the #define, ugh.

This means that on pseries machines we will misreport to firmware the
number of cores we support, by a factor of threads_per_core.

Fix it for now by updating the #define.

Fixes: 7cc851039d64 ("powerpc/pseries: Add POWER8NVL support to ibm,client-architecture-support call")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
powerpc/pseries: Add POWER8NVL support to ibm,client-architecture-support call 2016-06-24T17:18:20+00:00 Thomas Huth thuth@redhat.com 2016-05-31T05:51:17+00:00 a976f62a601a763ea37d116d5a9009a2eec9d0f3 commit 7cc851039d643a2ee7df4d18177150f2c3a484f5 upstream. If we do not provide the PVR for POWER8NVL, a guest on this system currently ends up in PowerISA 2.06 compatibility mode on KVM, since QEMU does not provide a generic PowerISA 2.07 mode yet. So some new instructions from POWER8 (like "mtvsrd") get disabled for the guest, resulting in crashes when using code compiled explicitly for POWER8 (e.g. with the "-mcpu=power8" option of GCC). Fixes: ddee09c099c3 ("powerpc: Add PVR for POWER8NVL processor") Signed-off-by: Thomas Huth <thuth@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 7cc851039d643a2ee7df4d18177150f2c3a484f5 upstream.

If we do not provide the PVR for POWER8NVL, a guest on this system
currently ends up in PowerISA 2.06 compatibility mode on KVM, since QEMU
does not provide a generic PowerISA 2.07 mode yet. So some new
instructions from POWER8 (like "mtvsrd") get disabled for the guest,
resulting in crashes when using code compiled explicitly for
POWER8 (e.g. with the "-mcpu=power8" option of GCC).

Fixes: ddee09c099c3 ("powerpc: Add PVR for POWER8NVL processor")
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
powerpc/eeh: Restore initial state in eeh_pe_reset_and_recover() 2016-06-08T01:14:36+00:00 Gavin Shan gwshan@linux.vnet.ibm.com 2016-04-27T01:14:51+00:00 0118086d556d96f85ecc5455016ed1f447267bda commit 5a0cdbfd17b90a89c64a71d8aec9773ecdb20d0d upstream. The function eeh_pe_reset_and_recover() is used to recover EEH error when the passthrou device are transferred to guest and backwards. The content in the device's config space will be lost on PE reset issued in the middle of the recovery. The function saves/restores it before/after the reset. However, config access to some adapters like Broadcom BCM5719 at this point will causes fenced PHB. The config space is always blocked and we save 0xFF's that are restored at late point. The memory BARs are totally corrupted, causing another EEH error upon access to one of the memory BARs. This restores the config space on those adapters like BCM5719 from the content saved to the EEH device when it's populated, to resolve above issue. Fixes: 5cfb20b9 ("powerpc/eeh: Emulate EEH recovery for VFIO devices") Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Reviewed-by: Russell Currey <ruscur@russell.cc> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 5a0cdbfd17b90a89c64a71d8aec9773ecdb20d0d upstream.

The function eeh_pe_reset_and_recover() is used to recover EEH
error when the passthrou device are transferred to guest and
backwards. The content in the device's config space will be lost
on PE reset issued in the middle of the recovery. The function
saves/restores it before/after the reset. However, config access
to some adapters like Broadcom BCM5719 at this point will causes
fenced PHB. The config space is always blocked and we save 0xFF's
that are restored at late point. The memory BARs are totally
corrupted, causing another EEH error upon access to one of the
memory BARs.

This restores the config space on those adapters like BCM5719
from the content saved to the EEH device when it's populated,
to resolve above issue.

Fixes: 5cfb20b9 ("powerpc/eeh: Emulate EEH recovery for VFIO devices")
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Reviewed-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Revert "powerpc/eeh: Fix crash in eeh_add_device_early() on Cell" 2016-06-08T01:14:35+00:00 Guilherme G. Piccoli gpiccoli@linux.vnet.ibm.com 2016-04-11T19:17:22+00:00 af64f74e5f72903de2ce891bde1386a6d3be712c commit c2078d9ef600bdbe568c89e5ddc2c6f15b7982c8 upstream. This reverts commit 89a51df5ab1d38b257300b8ac940bbac3bb0eb9b. The function eeh_add_device_early() is used to perform EEH initialization in devices added later on the system, like in hotplug/DLPAR scenarios. Since the commit 89a51df5ab1d ("powerpc/eeh: Fix crash in eeh_add_device_early() on Cell") a new check was introduced in this function - Cell has no EEH capabilities which led to kernel oops if hotplug was performed, so checking for eeh_enabled() was introduced to avoid the issue. However, in architectures that EEH is present like pSeries or PowerNV, we might reach a case in which no PCI devices are present on boot time and so EEH is not initialized. Then, if a device is added via DLPAR for example, eeh_add_device_early() fails because eeh_enabled() is false, and EEH end up not being enabled at all. This reverts the aforementioned patch since a new verification was introduced by the commit d91dafc02f42 ("powerpc/eeh: Delay probing EEH device during hotplug") and so the original Cell issue does not happen anymore. Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit c2078d9ef600bdbe568c89e5ddc2c6f15b7982c8 upstream.

This reverts commit 89a51df5ab1d38b257300b8ac940bbac3bb0eb9b.

The function eeh_add_device_early() is used to perform EEH
initialization in devices added later on the system, like in
hotplug/DLPAR scenarios. Since the commit 89a51df5ab1d ("powerpc/eeh:
Fix crash in eeh_add_device_early() on Cell") a new check was introduced
in this function - Cell has no EEH capabilities which led to kernel oops
if hotplug was performed, so checking for eeh_enabled() was introduced
to avoid the issue.

However, in architectures that EEH is present like pSeries or PowerNV,
we might reach a case in which no PCI devices are present on boot time
and so EEH is not initialized. Then, if a device is added via DLPAR for
example, eeh_add_device_early() fails because eeh_enabled() is false,
and EEH end up not being enabled at all.

This reverts the aforementioned patch since a new verification was
introduced by the commit d91dafc02f42 ("powerpc/eeh: Delay probing EEH
device during hotplug") and so the original Cell issue does not happen
anymore.

Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
powerpc/eeh: Don't report error in eeh_pe_reset_and_recover() 2016-06-08T01:14:35+00:00 Gavin Shan gwshan@linux.vnet.ibm.com 2016-04-27T01:14:50+00:00 d140d14201f8a0e5a0d3b690ebb346f380e60386 commit affeb0f2d3a9af419ad7ef4ac782e1540b2f7b28 upstream. The function eeh_pe_reset_and_recover() is used to recover EEH error when the passthrough device are transferred to guest and backwards, meaning the device's driver is vfio-pci or none. When the driver is vfio-pci that provides error_detected() error handler only, the handler simply stops the guest and it's not expected behaviour. On the other hand, no error handlers will be called if we don't have a bound driver. This ignores the error handler in eeh_pe_reset_and_recover() that reports the error to device driver to avoid the exceptional behaviour. Fixes: 5cfb20b9 ("powerpc/eeh: Emulate EEH recovery for VFIO devices") Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Reviewed-by: Russell Currey <ruscur@russell.cc> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit affeb0f2d3a9af419ad7ef4ac782e1540b2f7b28 upstream.

The function eeh_pe_reset_and_recover() is used to recover EEH
error when the passthrough device are transferred to guest and
backwards, meaning the device's driver is vfio-pci or none.
When the driver is vfio-pci that provides error_detected() error
handler only, the handler simply stops the guest and it's not
expected behaviour. On the other hand, no error handlers will
be called if we don't have a bound driver.

This ignores the error handler in eeh_pe_reset_and_recover()
that reports the error to device driver to avoid the exceptional
behaviour.

Fixes: 5cfb20b9 ("powerpc/eeh: Emulate EEH recovery for VFIO devices")
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Reviewed-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>