Impact: fix deadlock

This is in response to the following bug report:

Bug-Entry       : http://bugzilla.kernel.org/show_bug.cgi?id=12100
Subject         : resume (S2R) broken by Intel microcode module, on A110L
Submitter       : Andreas Mohr <andi@lisas.de>
Date            : 2008-11-25 08:48 (19 days old)
Handled-By      : Dmitry Adamushko <dmitry.adamushko@gmail.com>

[ The deadlock scenario has been discovered by Andreas Mohr ]

I think I might have a logical explanation why the system:

  (http://bugzilla.kernel.org/show_bug.cgi?id=12100)

might hang upon resuming, OTOH it should have likely hanged each and every time.

(1) possible deadlock in microcode_resume_cpu() if either 'if' section is
taken;

(2) now, I don't see it in spec. and can't experimentally verify it (newer
ucodes don't seem to be available for my Core2duo)... but logically-wise, I'd
think that when read upon resuming, the 'microcode revision' (MSR 0x8B) should
be back to its original one (we need to reload ucode anyway so it doesn't seem
logical if a cpu doesn't drop the version)... if so, the comparison with
memcmp() for the full 'struct cpu_signature' is wrong... and that's how one of
the aforementioned 'if' sections might have been triggered - leading to a
deadlock.

Obviously, in my tests I simulated loading/resuming with the ucode of the same
version (just to see that the file is loaded/re-loaded upon resuming) so this
issue has never popped up.

I'd appreciate if someone with an appropriate system might give a try to the
2nd patch (titled "fix a comparison && deadlock...").

In any case, the deadlock situation is a must-have fix.
Reported-by: NAndreas Mohr <andi@lisas.de>
Signed-off-by: NDmitry Adamushko <dmitry.adamushko@gmail.com>
Tested-by: NAndreas Mohr <andi@lisas.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Cc: <stable@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The favr-32 board code still refers to the old asm/arch header files
which were moved to mach/ some time ago.
Signed-off-by: NHaavard Skinnemoen <haavard.skinnemoen@atmel.com>

Enable JFFS2 write buffer support so that the kernel can access a root
filesystem in NAND flash.
Signed-off-by: NHaavard Skinnemoen <haavard.skinnemoen@atmel.com>

Impact: remove annoying bootup printk

It's perfectly normal for no AMD GART to be present, e.g., if you have
Intel CPUs.  None of the other iommu_init() functions makes noise when
it finds nothing.
Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Acked-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

There is an error in rh_alloc_fixed() of the Remote Heap code:
If there is at least one free block blk won't be NULL at the end of the
search loop, so -ENOMEM won't be returned and the else branch of
"if (bs == s || be == e)" will be taken, corrupting the management
structures.
Signed-off-by: NGuillaume Knispel <gknispel@proformatique.com>
Acked-by: NTimur Tabi <timur@freescale.com>
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

The commit e5e774d8
powerpc/fsl-booke: Fix problem with _tlbil_va being interrupted
introduce one issue. that casue the problem like this:

Kernel BUG at c00b19fc [verbose debug info unavailable]
Oops: Exception in kernel mode, sig: 5 [#1]
MPC8572 DS
Modules linked in:
NIP: c00b19fc LR: c00b1c34 CTR: c0064e88
REGS: ef02b7b0 TRAP: 0700   Not tainted  (2.6.28-rc8-00057-g1bda7128)
MSR: 00021000 <ME>  CR: 44048028  XER: 20000000
TASK = ef02c000[1] 'init' THREAD: ef02a000
GPR00: 00000001 ef02b860 ef02c000 eec201a0 c0dec2c0 00000000 000078a1 00000400
GPR08: c00b4e40 000078a1 c048ec00 a1780000 44048028 ecd26917 00000001 ef02b948
GPR16: ffffffea 0000020c 00000000 00000000 00000003 0000000a 00000000 000078a1
GPR24: eec201a0 00000000 ed849000 00000400 ef02b95c 00000001 ef02b978 ef02b984
NIP [c00b19fc] __find_get_block+0x24/0x238
LR [c00b1c34] __getblk+0x24/0x2a0
Call Trace:
[ef02b860] [c017b768] generic_make_request+0x290/0x328 (unreliable)
[ef02b8b0] [c00b1c34] __getblk+0x24/0x2a0
[ef02b910] [c00b4ae4] __bread+0x14/0xf8
[ef02b920] [c00fc228] ext2_get_branch+0xf0/0x138
[ef02b940] [c00fcc88] ext2_get_block+0xb8/0x828
[ef02ba00] [c00bbdc8] do_mpage_readpage+0x188/0x808
[ef02bac0] [c00bc5b4] mpage_readpages+0xec/0x144
[ef02bb50] [c00fba38] ext2_readpages+0x24/0x34
[ef02bb60] [c006ade0] __do_page_cache_readahead+0x150/0x230
[ef02bbb0] [c0064bdc] filemap_fault+0x31c/0x3e0
[ef02bbf0] [c00728b8] __do_fault+0x60/0x5b0
[ef02bc50] [c0011e0c] do_page_fault+0x2d8/0x4c4
[ef02bd10] [c000ed90] handle_page_fault+0xc/0x80
[ef02bdd0] [c00c7adc] set_brk+0x74/0x9c
[ef02bdf0] [c00c9274] load_elf_binary+0x70c/0x1180
[ef02be70] [c00945f0] search_binary_handler+0xa8/0x274
[ef02bea0] [c0095818] do_execve+0x19c/0x1d4
[ef02bed0] [c000766c] sys_execve+0x58/0x84
[ef02bef0] [c000e950] ret_from_syscall+0x0/0x3c
[ef02bfb0] [c009c6fc] sys_dup+0x24/0x6c
[ef02bfc0] [c0001e04] init_post+0xb0/0xf0
[ef02bfd0] [c046c1ac] kernel_init+0xcc/0xf4
[ef02bff0] [c000e6d0] kernel_thread+0x4c/0x68
Instruction dump:
4bffffa4 813f000c 4bffffac 9421ffb0 7c0802a6 7d800026 90010054 bf210034
91810030 7c0000a6 68008000 54008ffe <0f000000> 3d20c04e 3b29ffb8 38000008

The issue was the beqlr returns early but we haven't reenabled interrupts.
Signed-off-by: NDave Liu <daveliu@freescale.com>
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

Impact: prevents data corruption after a failed completion wait loop
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

Impact: set cmd buffer head and tail pointers to zero in case nobody else did
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

This patch will remove the section .note.gnu.build-id added in binutils
2.18 from the vmlinux.bin binary. Not removing this section results in a
huge multiple gigabyte binary and likewize large uImage.
Signed-off-by: NHans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Signed-off-by: NHaavard Skinnemoen <haavard.skinnemoen@atmel.com>

In order to always provide fully synchronized state to the debugger,
we might need to do a synchronize_user_stack().

A pair of hooks, arch_ptrace_stop_needed() and arch_ptrace_stop(),
exist to handle this kind of situation.  It was created for
the sake of IA64.

Use them, to flush the kernel side cached register windows
to the user stack, when necessary.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Impact: fix disabled MCE after resume

Don't prevent multiple initialization of MCEs.

Back from early prehistory mcheck_init() has a reentry check. Presumably
that was needed in very old kernels to prevent it entering twice.

But as Andreas points out this prevents CPU hotplug (and therefore resume)
to correctly reinitialize MCEs when a AP boots again after being
offlined.

Just drop the check.
Reported-by: NAndreas Herrmann <andreas.herrmann3@amd.com>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Tested-by: NAndreas Herrmann <andreas.herrmann3@amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: fix bug which can lead to panic in prealloc_protection_domains()
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

Presently limited to Cayman, Dreamcast, Microdev, and SystemH 7751.
Re-enable it for everyone once these have been fixed up.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Commit d015fe99 'powerpc/cell/axon-msi: Retry on missing interrupt'
has turned a rare failure to kexec on QS22 into a reproducible
error, which we have now analysed.

The problem is that after a kexec, the MSIC hardware still points
into the middle of the old ring buffer.  We set up the ring buffer
during reboot, but not the offset into it.  On older kernels, this
would cause a storm of thousands of spurious interrupts after a
kexec, which would most of the time get dropped silently.

With the new code, we time out on each interrupt, waiting for
it to become valid.  If more interrupts come in that we time
out on, this goes on indefinitely, which eventually leads to
a hard crash.

The solution in this commit is to read the current offset from
the MSIC when reinitializing it.  This now works correctly, as
expected.
Reported-by: NDirk Herrendoerfer <d.herrendoerfer@de.ibm.com>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

careful_allocation() was calling into the bootmem allocator for
nodes which had not been fully initialized and caused a previous
bug:  http://patchwork.ozlabs.org/patch/10528/  So, I merged a
few broken out loops in do_init_bootmem() to fix it.  That changed
the code ordering.

I think this bug is triggered by having reserved areas for a node
which are spanned by another node's contents.  In the
mark_reserved_regions_for_nid() code, we attempt to reserve the
area for a node before we have allocated the NODE_DATA() for that
nid.  We do this since I reordered that loop.  I suck.

This is causing crashes at bootup on some systems, as reported
by Jon Tollefson.

This may only present on some systems that have 16GB pages
reserved.  But, it can probably happen on any system that is
trying to reserve large swaths of memory that happen to span other
nodes' contents.

This commit ensures that we do not touch bootmem for any node which
has not been initialized, and also removes a compile warning about
an unused variable.
Signed-off-by: NDave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

It looks like most of the hugetlb code is doing the correct thing if
hugepages are not supported, but the mmap code is not.  If we get into
the mmap code when hugepages are not supported, such as in an LPAR
which is running Active Memory Sharing, we can oops the kernel.  This
fixes the oops being seen in this path.

oops: Kernel access of bad area, sig: 11 [#1]
SMP NR_CPUS=1024 NUMA pSeries
Modules linked in: nfs(N) lockd(N) nfs_acl(N) sunrpc(N) ipv6(N) fuse(N) loop(N)
dm_mod(N) sg(N) ibmveth(N) sd_mod(N) crc_t10dif(N) ibmvscsic(N)
scsi_transport_srp(N) scsi_tgt(N) scsi_mod(N)
Supported: No
NIP: c000000000038d60 LR: c00000000003945c CTR: c0000000000393f0
REGS: c000000077e7b830 TRAP: 0300   Tainted: G
(2.6.27.5-bz50170-2-ppc64)
MSR: 8000000000009032 <EE,ME,IR,DR>  CR: 44000448  XER: 20000001
DAR: c000002000af90a8, DSISR: 0000000040000000
TASK = c00000007c1b8600[4019] 'hugemmap01' THREAD: c000000077e78000 CPU: 6
GPR00: 0000001fffffffe0 c000000077e7bab0 c0000000009a4e78 0000000000000000
GPR04: 0000000000010000 0000000000000001 00000000ffffffff 0000000000000001
GPR08: 0000000000000000 c000000000af90c8 0000000000000001 0000000000000000
GPR12: 000000000000003f c000000000a73880 0000000000000000 0000000000000000
GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000010000
GPR20: 0000000000000000 0000000000000003 0000000000010000 0000000000000001
GPR24: 0000000000000003 0000000000000000 0000000000000001 ffffffffffffffb5
GPR28: c000000077ca2e80 0000000000000000 c00000000092af78 0000000000010000
NIP [c000000000038d60] .slice_get_unmapped_area+0x6c/0x4e0
LR [c00000000003945c] .hugetlb_get_unmapped_area+0x6c/0x80
Call Trace:
[c000000077e7bbc0] [c00000000003945c] .hugetlb_get_unmapped_area+0x6c/0x80
[c000000077e7bc30] [c000000000107e30] .get_unmapped_area+0x64/0xd8
[c000000077e7bcb0] [c00000000010b140] .do_mmap_pgoff+0x140/0x420
[c000000077e7bd80] [c00000000000bf5c] .sys_mmap+0xc4/0x140
[c000000077e7be30] [c0000000000086b4] syscall_exit+0x0/0x40
Instruction dump:
fac1ffb0 fae1ffb8 fb01ffc0 fb21ffc8 fb41ffd0 fb61ffd8 fb81ffe0 fbc1fff0
fbe1fff8 f821fef1 f8c10158 f8e10160 <7d49002e> f9010168 e92d01b0 eb4902b0
Signed-off-by: NBrian King <brking@linux.vnet.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

... for the removal of it from asm-generic/local.h
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

VMI initialiation can relocate the fixmap, causing early_ioremap to
malfunction if it is initialized before the relocation.  To fix this,
VMI activation is split into two phases; the detection, which must
happen before setting up ioremap, and the activation, which must happen
after parsing early boot parameters.

This fixes a crash on boot when VMI is enabled under VMware.
Signed-off-by: NZachary Amsden <zach@vmware.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix kernel-doc notation to use correct syntax.  Even though this should be
moved to where the function is actually implemented...
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

If it is reasonable to apply PTR_ERR to the result of calling clk_get, then
that result should first be tested with IS_ERR, not with !.

The semantic patch that makes this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@@
expression E,E1;
@@

if (
-   E == NULL
+   IS_ERR(E)
   ) { <+... when != E = E1
        PTR_ERR(E)
       ...+> }
// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

An example calling sequence which we did see:

copy_user_highpage -> kmap_atomic -> flush_tlb_page -> _tlbil_va

We got interrupted after setting up the MAS registers before the
tlbwe and the interrupt handler that caused the interrupt also did
a kmap_atomic (ide code) and thus on returning from the interrupt
the MAS registers no longer contained the proper values.

Since we dont save/restore MAS registers for normal interrupts we
need to disable interrupts in _tlbil_va to ensure atomicity.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

Signed-off-by: NDavid Daney <ddaney@caviumnetworks.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

dma_free_noncoherent() and dma_free_coherent() are missing calls to
plat_unmap_dma_mem().  This patch adds them.
Signed-off-by: NDavid Daney <ddaney@caviumnetworks.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The header path in the help text for the RUNTIME_DEBUG config option is
obsolete and needs to be updated to match the new location of
architecture-specific header files. While at it, fix the spelling mistake.
Signed-off-by: NDmitri Vorobiev <dmitri.vorobiev@movial.fi>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

For MIPS R2, use the EI and DI instructions to enable and disable
interrupts.
Signed-off-by: NTomaso Paoletti <tpaoletti@caviumnetworks.com>
Signed-off-by: NDavid Daney <ddaney@caviumnetworks.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The cuboot-acadia.c wrapper can cause assembler errors on some
toolchains due to the lack of the proper BOOTCFLAGS.  This adds
the proper flags for the file.
Signed-off-by: NJosh Boyer <jwboyer@linux.vnet.ibm.com>

... as it is defined with memcpy, therefore no copy_page symbol to
export.
Signed-off-by: NNicolas Pitre <nico@cam.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

From: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Give the correct size when reserving the interrupt vector table.  It should be
a page not a single byte.
Signed-off-by: NAkira Takeuchi <takeuchi.akr@jp.panasonic.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix the preemption resume_kernel() routine by inverting the test to see
whether interrupts are off (IM7 is all enabled, not all disabled).

Furthermore, interrupts should be disabled on entry to resume_kernel() so that
they're correctly set for jumping to restore_all() and doing the need
reschedule test.
Signed-off-by: NAkira Takeuchi <takeuchi.akr@jp.panasonic.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Discard low-prioriy Tx interrupts when closing an MN10300 on-chip serial port.

The MN10300 on-chip serial port uses three interrupts to manage its serial
ports:

 (1) A very high priority interrupt that drives virtual DMA for Rx.

 (2) A very high priority interrupt that drives virtual DMA for Tx.

 (3) A normal priority virtual interrupt that does the normal UART interrupt
     stuff and is shared between Rx and Tx.

mn10300_serial_stop_tx() only disables the high priority Tx interrupt.  It
doesn't also disable the normal priority one because it is shared with Rx.

However, the high priority interrupt may interrupt local_irq_disabled()
sections, and so may have queued up a low priority virtual interrupt whilst the
UART driver is asking for the Tx interrupt to be disabled.

The result of this can be an oops when we try to process the interrupt in
mn10300_serial_transmit_interrupt() as port->uart.info and port->uart.info->tty
may have gone away.

To deal with this, if either of those pointers is NULL, we make sure the
high-priority Tx interrupt is disabled and discard the interrupt.  The low
priority interrupt is disabled by the mn10300_serial_pic irq_chip table.
Signed-off-by: NAkira Takeuchi <takeuchi.akr@jp.panasonic.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Include the linux/page.h header into the MN10300 kernel linker script thus
allowing us to use PAGE_SIZE macro instead of a numeric constant.

Also use the PERCPU macro instead of an explicit section definition.
Signed-off-by: NCyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mconsole_init() passed 256 bytes as length in os_create_unix_socket, while
the sizeof UNIX_PATH_MAX is 108. This patch fixes that problem and avoids
a big overrun bug reported on UML bootup.

sockaddr_un.sun_path is UNIX_PATH_MAX long which causes the problem.
Reported-by: NVikas K Managutte <vikki.km@gmail.com>
Reported-by: NSarvesh Kumar Lal Das <skldas@gmail.com>
Signed-off-by: NBalbir Singh <balbir@linux.vnet.ibm.com>
Reviewed-by: NPekka Enberg <penberg@cs.helsinki.fi>
Reviewed-by: NWANG Cong <wangcong@zeuux.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: <stable@kernel.org>		[please check with Jeff]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Certain X11 servers such as the SIS server will only work if PCI mmap is
implemented.  This patch implements PCI mmap but to be on the same side
so close to a release it only supports uncached mappings so performance
will not be optimal for some uses such as framebuffers.

Thanks to Zhang Le <r0bertz@gentoo.org> for the original report and
testing.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

With the introduction of the generic affinity autoselector,
irq_select_affinity(), IRQs are now being retargetted,
using a default mask, via the request_irq() path.
This results in all IRQs targetted at CPU 0.

SN Altix assigns affinity in the SN PROM, and does not
expect that to be changed as part of request_irq().

Set the IRQ_AFFINITY_SET flag to prevent
request_irq() from resetting affinity.
Signed-off-by: NJohn Keller <jpk@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

The generic_defconfig has three section mismatches.  This clears
arch_unregister_cpu()
Signed-off-by: NRobin Holt <holt@sgi.com>
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

The generic_defconfig has three section mismatches.  This clears up
sn_check_wars().
Signed-off-by: NRobin Holt <holt@sgi.com>
Signed-off-by: NJack Steiner <steiner@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

The AUTOFS=y and AUTOFS4=y causes problems with some distros versions of
automount.  I turned both of those to =m and then followed the default
prompts for everything else.  I did notice that CONFIG_PNP_DEBUG got
changed to CONFIG_PNP_DEBUG_MESSAGES and the default was a =y so I turned
that back to a =n.
Signed-off-by: NRobin Holt <holt@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

As noted by Akinobu Mita in patch b1fceac2,
alloc_bootmem and related functions never return NULL and always return a
zeroed region of memory.  Thus a NULL test or memset after calls to these
functions is unnecessary.
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NTony Luck <tony.luck@intel.com>

CC      arch/ia64/kernel/asm-offsets.s
In file included from include/linux/bitops.h:17,
                 from include/linux/kernel.h:15,
                 from include/linux/sched.h:52,
                 from arch/ia64/kernel/asm-offsets.c:9:
arch/ia64/include/asm/bitops.h: In function 'set_bit':
arch/ia64/include/asm/bitops.h:47: error: implicit declaration of function 'BUILD_BUG_ON'

Obvious inclusion of kernel.h doesn't fix it, because of circular dependencies
involving fls.h and log2(). Fixing the latter requires some serious header surgery,
it seems, so just remove BUILD_BUG_ON for now.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>