linux-stable.git/arch/powerpc, branch v4.9.77

powerpc/perf: Dereference BHRB entries safely

2017-12-29T16:43:00+00:00

commit f41d84dddc66b164ac16acf3f584c276146f1c48 upstream.

It's theoretically possible that branch instructions recorded in
BHRB (Branch History Rolling Buffer) entries have already been
unmapped before they are processed by the kernel. Hence, trying to
dereference such memory location will result in a crash. eg:

    Unable to handle kernel paging request for data at address 0xd000000019c41764
    Faulting instruction address: 0xc000000000084a14
    NIP [c000000000084a14] branch_target+0x4/0x70
    LR [c0000000000eb828] record_and_restart+0x568/0x5c0
    Call Trace:
    [c0000000000eb3b4] record_and_restart+0xf4/0x5c0 (unreliable)
    [c0000000000ec378] perf_event_interrupt+0x298/0x460
    [c000000000027964] performance_monitor_exception+0x54/0x70
    [c000000000009ba4] performance_monitor_common+0x114/0x120

Fix it by deferefencing the addresses safely.

Fixes: 691231846ceb ("powerpc/perf: Fix setting of "to" addresses for BHRB")
Suggested-by: Naveen N. Rao 
Signed-off-by: Ravi Bangoria 
Reviewed-by: Naveen N. Rao 
[mpe: Use probe_kernel_read() which is clearer, tweak change log]
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

powerpc/perf/hv-24x7: Fix incorrect comparison in memord

2017-12-20T09:07:32+00:00

[ Upstream commit 05c14c03138532a3cb2aa29c2960445c8753343b ]

In the hv-24x7 code there is a function memord() which tries to
implement a sort function return -1, 0, 1. However one of the
conditions is incorrect, such that it can never be true, because we
will have already returned.

I don't believe there is a bug in practice though, because the
comparisons are an optimisation prior to calling memcmp().

Fix it by swapping the second comparision, so it can be true.

Reported-by: David Binderman 
Signed-off-by: Michael Ellerman 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

powerpc/ipic: Fix status get and status clear

2017-12-20T09:07:28+00:00

[ Upstream commit 6b148a7ce72a7f87c81cbcde48af014abc0516a9 ]

IPIC Status is provided by register IPIC_SERSR and not by IPIC_SERMR
which is the mask register.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

powerpc/opal: Fix EBUSY bug in acquiring tokens

2017-12-20T09:07:28+00:00

[ Upstream commit 71e24d7731a2903b1ae2bba2b2971c654d9c2aa6 ]

The current code checks the completion map to look for the first token
that is complete. In some cases, a completion can come in but the
token can still be on lease to the caller processing the completion.
If this completed but unreleased token is the first token found in the
bitmap by another tasks trying to acquire a token, then the
__test_and_set_bit call will fail since the token will still be on
lease. The acquisition will then fail with an EBUSY.

This patch reorganizes the acquisition code to look at the
opal_async_token_map for an unleased token. If the token has no lease
it must have no outstanding completions so we should never see an
EBUSY, unless we have leased out too many tokens. Since
opal_async_get_token_inrerruptible is protected by a semaphore, we
will practically never see EBUSY anymore.

Fixes: 8d7248232208 ("powerpc/powernv: Infrastructure to support OPAL async completion")
Signed-off-by: William A. Kennington III 
Signed-off-by: Michael Ellerman 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

powerpc/powernv/cpufreq: Fix the frequency read by /proc/cpuinfo

2017-12-20T09:07:27+00:00

[ Upstream commit cd77b5ce208c153260ed7882d8910f2395bfaabd ]

The call to /proc/cpuinfo in turn calls cpufreq_quick_get() which
returns the last frequency requested by the kernel, but may not
reflect the actual frequency the processor is running at. This patch
makes a call to cpufreq_get() instead which returns the current
frequency reported by the hardware.

Fixes: fb5153d05a7d ("powerpc: powernv: Implement ppc_md.get_proc_freq()")
Signed-off-by: Shriya 
Signed-off-by: Michael Ellerman 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

powerpc/64: Fix checksum folding in csum_tcpudp_nofold and ip_fast_csum_nofold

2017-12-16T15:25:47+00:00

commit b492f7e4e07a28e706db26cf4943bb0911435426 upstream.

These functions compute an IP checksum by computing a 64-bit sum and
folding it to 32 bits (the "nofold" in their names refers to folding
down to 16 bits).  However, doing (u32) (s + (s >> 32)) is not
sufficient to fold a 64-bit sum to 32 bits correctly.  The addition
can produce a carry out from bit 31, which needs to be added in to
the sum to produce the correct result.

To fix this, we copy the from64to32() function from lib/checksum.c
and use that.

Signed-off-by: Paul Mackerras 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

powerpc/powernv/ioda2: Gracefully fail if too many TCE levels requested

2017-12-14T08:28:21+00:00

[ Upstream commit 7aafac11e308d37ed3c509829bb43d80c1811ac3 ]

The IODA2 specification says that a 64 DMA address cannot use top 4 bits
(3 are reserved and one is a "TVE select"); bottom page_shift bits
cannot be used for multilevel table addressing either.

The existing IODA2 table allocation code aligns the minimum TCE table
size to PAGE_SIZE so in the case of 64K system pages and 4K IOMMU pages,
we have 64-4-12=48 bits. Since 64K page stores 8192 TCEs, i.e. needs
13 bits, the maximum number of levels is 48/13 = 3 so we physically
cannot address more and EEH happens on DMA accesses.

This adds a check that too many levels were requested.

It is still possible to have 5 levels in the case of 4K system page size.

Signed-off-by: Alexey Kardashevskiy 
Acked-by: Gavin Shan 
Signed-off-by: Michael Ellerman 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

axonram: Fix gendisk handling

2017-12-14T08:28:21+00:00

[ Upstream commit 672a2c87c83649fb0167202342ce85af9a3b4f1c ]

It is invalid to call del_gendisk() when disk->queue is NULL. Fix error
handling in axon_ram_probe() to avoid doing that.

Also del_gendisk() does not drop a reference to gendisk allocated by
alloc_disk(). That has to be done by put_disk(). Add that call where
needed.

Reported-by: Dan Carpenter 
Signed-off-by: Jan Kara 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

powerpc/64: Fix checksum folding in csum_add()

2017-12-14T08:28:17+00:00

[ Upstream commit 6ad966d7303b70165228dba1ee8da1a05c10eefe ]

Paul's patch to fix checksum folding, commit b492f7e4e07a ("powerpc/64:
Fix checksum folding in csum_tcpudp_nofold and ip_fast_csum_nofold")
missed a case in csum_add(). Fix it.

Signed-off-by: Shile Zhang 
Acked-by: Paul Mackerras 
Signed-off-by: Michael Ellerman 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

powerpc: Fix compiling a BE kernel with a powerpc64le toolchain

2017-12-14T08:28:17+00:00

[ Upstream commit 4dc831aa88132f835cefe876aa0206977c4d7710 ]

GCC can compile with either endian, but the default ABI version is set
based on the default endianness of the toolchain. Alan Modra says:

  you need both -mbig and -mabi=elfv1 to make a powerpc64le gcc
  generate powerpc64 code

The opposite is true for powerpc64 when generating -mlittle it
requires -mabi=elfv2 to generate v2 ABI, which we were already doing.

This change adds ABI annotations together with endianness for all cases,
LE and BE. This fixes the case of building a BE kernel with a toolchain
that is LE by default.

Signed-off-by: Nicholas Piggin 
Tested-by: Naveen N. Rao 
Signed-off-by: Michael Ellerman 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman