linux-stable.git/arch/powerpc/kernel, branch v3.4.99

powerpc/sysfs: Disable writing to PURR in guest mode

2014-07-09T17:51:22+00:00

commit d1211af3049f4c9c1d8d4eb8f8098cc4f4f0d0c7 upstream.

arch/powerpc/kernel/sysfs.c exports PURR with write permission.
This may be valid for kernel in phyp mode. But writing to
the file in guest mode causes crash due to a priviledge violation

Signed-off-by: Madhavan Srinivasan 
Signed-off-by: Benjamin Herrenschmidt 
[Backported to 3.4: adjust context]
Signed-off-by: Yijing Wang 
Signed-off-by: Greg Kroah-Hartman

powerpc/pseries: Duplicate dtl entries sometimes sent to userspace

2014-07-09T17:51:22+00:00

commit 84b073868b9d9e754ae48b828337633d1b386482 upstream.

When reading from the dispatch trace log (dtl) userspace interface, I
sometimes see duplicate entries. One example:

# hexdump -C dtl.out

00000000  07 04 00 0c 00 00 48 44  00 00 00 00 00 00 00 00
00000010  00 0c a0 b4 16 83 6d 68  00 00 00 00 00 00 00 00
00000020  00 00 00 00 10 00 13 50  80 00 00 00 00 00 d0 32

00000030  07 04 00 0c 00 00 48 44  00 00 00 00 00 00 00 00
00000040  00 0c a0 b4 16 83 6d 68  00 00 00 00 00 00 00 00
00000050  00 00 00 00 10 00 13 50  80 00 00 00 00 00 d0 32

The problem is in scan_dispatch_log() where we call dtl_consumer()
but bail out before incrementing the index.

To fix this I moved dtl_consumer() after the timebase comparison.

Signed-off-by: Anton Blanchard 
Signed-off-by: Benjamin Herrenschmidt 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings 
Cc: Yijing Wang 
Signed-off-by: Greg Kroah-Hartman

powerpc/pseries/lparcfg: Fix possible overflow are more than 1026

2014-07-09T17:51:21+00:00

commit 5676005acf26ab7e924a8438ea4746e47d405762 upstream.

need set '\0' for 'local_buffer'.

SPLPAR_MAXLENGTH is 1026, RTAS_DATA_BUF_SIZE is 4096. so the contents of
rtas_data_buf may truncated in memcpy.

if contents are really truncated.
  the splpar_strlen is more than 1026. the next while loop checking will
  not find the end of buffer. that will cause memory access violation.

Signed-off-by: Chen Gang 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Ben Hutchings 
Cc: Yijing Wang 
Signed-off-by: Greg Kroah-Hartman

powerpc: Don't Oops when accessing /proc/powerpc/lparcfg without hypervisor

2014-07-09T17:51:21+00:00

commit f5f6cbb61610b7bf9d9d96db9c3979d62a424bab upstream.

/proc/powerpc/lparcfg is an ancient facility (though still actively used)
which allows access to some informations relative to the partition when
running underneath a PAPR compliant hypervisor.

It makes no sense on non-pseries machines. However, currently, not only
can it be created on these if the kernel has pseries support, but accessing
it on such a machine will crash due to trying to do hypervisor calls.

In fact, it should also not do HV calls on older pseries that didn't have
an hypervisor either.

Finally, it has the plumbing to be a module but is a "bool" Kconfig option.

This fixes the whole lot by turning it into a machine_device_initcall
that is only created on pseries, and adding the necessary hypervisor
check before calling the H_GET_EM_PARMS hypercall

Signed-off-by: Benjamin Herrenschmidt 
[bwh: Backported to 3.2: lparcfg_cleanup() was a bit different]
Signed-off-by: Ben Hutchings 
Cc: Yijing Wang 
Signed-off-by: Greg Kroah-Hartman

powerpc/smp: Section mismatch from smp_release_cpus to __initdata spinning_secondaries

2014-07-09T17:51:21+00:00

commit 8246aca7058f3f2c2ae503081777965cd8df7b90 upstream.

the smp_release_cpus is a normal funciton and called in normal environments,
  but it calls the __initdata spinning_secondaries.
  need modify spinning_secondaries to match smp_release_cpus.

the related warning:
  (the linker report boot_paca.33377, but it should be spinning_secondaries)

-----------------------------------------------------------------------------

WARNING: arch/powerpc/kernel/built-in.o(.text+0x23176): Section mismatch in reference from the function .smp_release_cpus() to the variable .init.data:boot_paca.33377
The function .smp_release_cpus() references
the variable __initdata boot_paca.33377.
This is often because .smp_release_cpus lacks a __initdata
annotation or the annotation of boot_paca.33377 is wrong.

WARNING: arch/powerpc/kernel/built-in.o(.text+0x231fe): Section mismatch in reference from the function .smp_release_cpus() to the variable .init.data:boot_paca.33377
The function .smp_release_cpus() references
the variable __initdata boot_paca.33377.
This is often because .smp_release_cpus lacks a __initdata
annotation or the annotation of boot_paca.33377 is wrong.

-----------------------------------------------------------------------------

Signed-off-by: Chen Gang 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Ben Hutchings 
Cc: Yijing Wang 
Signed-off-by: Greg Kroah-Hartman

powerpc: Fix emulation of illegal instructions on PowerNV platform

2014-07-09T17:51:21+00:00

commit bf593907f7236e95698a76b7c7a2bbf8b1165327 upstream.

Normally, the kernel emulates a few instructions that are unimplemented
on some processors (e.g. the old dcba instruction), or privileged (e.g.
mfpvr).  The emulation of unimplemented instructions is currently not
working on the PowerNV platform.  The reason is that on these machines,
unimplemented and illegal instructions cause a hypervisor emulation
assist interrupt, rather than a program interrupt as on older CPUs.
Our vector for the emulation assist interrupt just calls
program_check_exception() directly, without setting the bit in SRR1
that indicates an illegal instruction interrupt.  This fixes it by
making the emulation assist interrupt set that bit before calling
program_check_interrupt().  With this, old programs that use no-longer
implemented instructions such as dcba now work again.

Signed-off-by: Paul Mackerras 
Signed-off-by: Benjamin Herrenschmidt 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings 
Cc: Yijing Wang 
Signed-off-by: Greg Kroah-Hartman

powerpc: fix typo 'CONFIG_PMAC'

2014-07-07T01:49:20+00:00

commit 6e0fdf9af216887e0032c19d276889aad41cad00 upstream.

Commit b0d278b7d3ae ("powerpc/perf_event: Reduce latency of calling
perf_event_do_pending") added a check for CONFIG_PMAC were a check for
CONFIG_PPC_PMAC was clearly intended.

Fixes: b0d278b7d3ae ("powerpc/perf_event: Reduce latency of calling perf_event_do_pending")
Signed-off-by: Paul Bolle 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman

powerpc: Align p_dyn, p_rela and p_st symbols

2014-03-24T04:37:05+00:00

commit a5b2cf5b1af424ee3dd9e3ce6d5cea18cb927e67 upstream.

The 64bit relocation code places a few symbols in the text segment.
These symbols are only 4 byte aligned where they need to be 8 byte
aligned. Add an explicit alignment.

Signed-off-by: Anton Blanchard 
Tested-by: Laurent Dufour 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman

powerpc/crashdump : Fix page frame number check in copy_oldmem_page

2014-03-11T23:10:00+00:00

commit f5295bd8ea8a65dc5eac608b151386314cb978f1 upstream.

In copy_oldmem_page, the current check using max_pfn and min_low_pfn to
decide if the page is backed or not, is not valid when the memory layout is
not continuous.

This happens when running as a QEMU/KVM guest, where RTAS is mapped higher
in the memory. In that case max_pfn points to the end of RTAS, and a hole
between the end of the kdump kernel and RTAS is not backed by PTEs. As a
consequence, the kdump kernel is crashing in copy_oldmem_page when accessing
in a direct way the pages in that hole.

This fix relies on the memblock's service memblock_is_region_memory to
check if the read page is part or not of the directly accessible memory.

Signed-off-by: Laurent Dufour 
Tested-by: Mahesh Salgaonkar 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman

powerpc: Make sure "cache" directory is removed when offlining cpu

2014-02-06T19:05:48+00:00

commit 91b973f90c1220d71923e7efe1e61f5329806380 upstream.

The code in remove_cache_dir() is supposed to remove the "cache"
subdirectory from the sysfs directory for a CPU when that CPU is
being offlined.  It tries to do this by calling kobject_put() on
the kobject for the subdirectory.  However, the subdirectory only
gets removed once the last reference goes away, and the reference
being put here may well not be the last reference.  That means
that the "cache" subdirectory may still exist when the offlining
operation has finished.  If the same CPU subsequently gets onlined,
the code tries to add a new "cache" subdirectory.  If the old
subdirectory has not yet been removed, we get a WARN_ON in the
sysfs code, with stack trace, and an error message printed on the
console.  Further, we ultimately end up with an online cpu with no
"cache" subdirectory.

This fixes it by doing an explicit kobject_del() at the point where
we want the subdirectory to go away.  kobject_del() removes the sysfs
directory even though the object still exists in memory.  The object
will get freed at some point in the future.  A subsequent onlining
operation can create a new sysfs directory, even if the old object
still exists in memory, without causing any problems.

Signed-off-by: Paul Mackerras 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman