start_secondary() is called shortly after _start and also via
cpu_idle()->cpu_die()->pseries_mach_cpu_die()
start_secondary() expects a preempt_count() of 0. pseries_mach_cpu_die() is
called via the cpu_idle() routine with preemption disabled, resulting in the
following repeating message during rapid cpu offline/online tests
with CONFIG_PREEMPT=y:
BUG: scheduling while atomic: swapper/0/0x00000002
Modules linked in: autofs4 binfmt_misc dm_mirror dm_region_hash dm_log [last unloaded: scsi_wait_scan]
Call Trace:
[c00000010e7079c0] [c0000000000133ec] .show_stack+0xd8/0x218 (unreliable)
[c00000010e707aa0] [c0000000006a47f0] .dump_stack+0x28/0x3c
[c00000010e707b20] [c00000000006e7a4] .__schedule_bug+0x7c/0x9c
[c00000010e707bb0] [c000000000699d9c] .schedule+0x104/0x800
[c00000010e707cd0] [c000000000015b24] .cpu_idle+0x1c4/0x1d8
[c00000010e707d70] [c0000000006aa1b4] .start_secondary+0x398/0x3d4
[c00000010e707e30] [c000000000008278] .start_secondary_resume+0x10/0x14
Move the cpu_die() call inside the existing preemption enabled block of
cpu_idle(). This is safe as the idle task is affined to a single CPU so the
debug_smp_processor_id() tests (from cpu_should_die()) won't trigger as we are
in a "migration disabled" region.
Signed-off-by: Darren Hart <dvhltc@us.ibm.com>
Acked-by: Will Schmidt <will_schmidt@vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Nathan Fontenot <nfont@austin.ibm.com>
Cc: Robert Jennings <rcj@linux.vnet.ibm.com>
Cc: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
list_for_each_entry binds its first argument to a non-null value, and thus
any null test on the value of that argument is superfluous.
The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@@
iterator I;
expression x,E,E1,E2;
statement S,S1,S2;
@@
I(x,...) { <...
- if (x != NULL || ...)
S
...> }
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
for_each_node_by_name binds its first argument to a non-null value, and
thus any null test on the value of that argument is superfluous.
The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@@
iterator I;
expression x,E;
@@
I(x,...) { <...
(
- (x != NULL) &&
E
...> }
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
for_each_node_by_name only exits when its first argument is NULL, and a
subsequent call to of_node_put on that argument is unnecessary.
The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@@
iterator name for_each_node_by_name;
expression np,E;
identifier l;
@@
for_each_node_by_name(np,...) {
... when != break;
when != goto l;
}
... when != np = E
- of_node_put(np);
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Reviewed-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
During kdump we run the crash handlers first then stop all other CPUs.
We really want to stop all CPUs as close to the fail as possible and also
have a very controlled environment for running the crash handlers, so it
makes sense to reverse the order.
Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Matt Evans <matt@ozlabs.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The code is wrapped in an #if 0, but it's wrong so we may as well fix it.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Use is_32bit_task() helper to test 32 bit binary.
Signed-off-by: Denis Kirjanov <dkirjanov@kernel.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Some modules (like eHCA) want to map all of kernel memory, for this to
work with a relocated kernel, we need to export kernstart_addr so
modules can use PHYSICAL_START and memstart_addr so they could use
MEMORY_START. Note that the 32bit code already exports these symbols.
Signed-off-By: Sonny Rao <sonnyrao@us.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This makes the 64-bit kernel use 64-bit signed integers for the counter
(effectively supporting 32-bit of active count in the semaphore), thus
avoiding things like overflow of the mmap_sem if you use a really crazy
number of threads
Note: Ideally the type in the structure should be atomic_long_t rather
than "long". However, there's some nasty issues with that. It needs to
be initialized statically -and- lib/rwsem.c does things like
sem->count = RWSEM_UNLOCKED_VALUE;
Now, if you mix in the fact that atomic_* types are actually structures
with one member and note typedefs of a scalar, it makes its really nasty.
So I stuck to what we did before using a long and casts for now.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* 'for-upstream/pvhvm' of git://xenbits.xensource.com/people/ianc/linux-2.6:
xen: pvhvm: make it clearer that XEN_UNPLUG_* define bits in a bitfield
xen: pvhvm: rename xen_emul_unplug=ignore to =unnnecessary
xen: pvhvm: allow user to request no emulated device unplug
dev_name always dereferences its argument, so it should not be called if
the argument is NULL. The function indeed later tests the argument for
being NULL.
The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@@
expression dev,E;
@@
*dev_name(dev)
... when != dev = E
(
*dev == NULL
|
*dev != NULL
)
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The interrupt stacks need to be indexed by the physical cpu since the
critical, debug and machine check handlers use the contents of SPRN_PIR to
index the critirq_ctx, dbgirq_ctx, and mcheckirq_ctx arrays.
Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
There are two entries for .cpu_user_features in
arch/powerpc/kernel/cputable.c. Remove the one that doesn't belong
Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Clear the machine check syndrom register before enabling machine check
interrupts. The initial state of the tlb can lead to parity errors being
flagged early after a cold boot.
Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Device tree update for the Applied micro processor 460ex on-chip SATA
Signed-off-by: Rupjyoti Sarmah <rsarmah@amcc.com>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
It is not immediately clear what this option causes to become
ignored. The actual meaning is that it is not necessary to unplug the
emulated devices to safely use the PV ones, even if the platform does
not support the unplug protocol. (pressumably the user will only add
this option if they have ensured that their domain configuration is
safe).
I think xen_emul_unplug=unnecessary better captures this.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Stefano Stabellini <Stefano.Stabellini@eu.citrix.com>
this allows the user to disable pvhvm and revert to emulated devices
in case of a system misconfiguration (e.g. initramfs with only
emulated drivers in it).
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Stefano Stabellini <Stefano.Stabellini@eu.citrix.com>
The recent commit to add constant optimization to hweight implicitly broke
the Blackfin arch. Seems we were missed when all the other arches were
fixed with renames.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
* 'kvm-updates/2.6.36' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: PIT: free irq source id in handling error path
KVM: destroy workqueue on kvm_create_pit() failures
KVM: fix poison overwritten caused by using wrong xstate size
The "Configure" word tends to make user believe they have to say 'yes'
to be able to choose the number of procs/nodes. "Enable" should be
unambiguous enough.
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Each board can override the default sdhci host capabilities.
Some board has broken features by hardwares and support 8-bit bandwidth.
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix a boot crash when apic=debug is used and the APIC is
not properly initialized.
This issue appears during Xen Dom0 kernel boot but the
fix is generic and the crash could occur on real hardware
as well.
Signed-off-by: Daniel Kiper <dkiper@net-space.pl>
Cc: xen-devel@lists.xensource.com
Cc: konrad.wilk@oracle.com
Cc: jeremy@goop.org
Cc: <stable@kernel.org> # .35.x, .34.x, .33.x, .32.x
LKML-Reference: <20100819224616.GB9967@router-fw-old.local.net-space.pl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When testing cpu hotplug code on 32-bit we kept hitting the "CPU%d:
Stuck ??" message due to multiple cores concurrently accessing the
cpu_callin_mask, among others.
Since these codepaths are not protected from concurrent access due to
the fact that there's no sane reason for making an already complex
code unnecessarily more complex - we hit the issue only when insanely
switching cores off- and online - serialize hotplugging cores on the
sysfs level and be done with it.
[ v2.1: fix !HOTPLUG_CPU build ]
Cc: <stable@kernel.org>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
LKML-Reference: <20100819181029.GC17171@aftab>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Fix dummy inline stubs for trampoline-related functions when no
trampolines exist (until we get rid of the no-trampoline case
entirely.)
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Joerg Roedel <joerg.roedel@amd.com>
Cc: Borislav Petkov <borislav.petkov@amd.com>
LKML-Reference: <4C6C294D.3030404@zytor.com>
arch/ia64/kernel/process.c:636: error: conflicting types for ‘sys_execve’
commit d7627467b7
Make do_execve() take a const filename pointer
Missed the declaration of sys_execve in the ia64 asm/unistd.h (perhaps
because there is no reason for it to be there ... it might be a left over
from the COMPAT code?). Just delete the conflicting version.
Signed-off-by: Tony Luck <tony.luck@intel.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu:
m68knommu: include sched.h in ColdFire/SPI driver
m68knommu: formatting of pointers in printk()
m68knommu: arch/m68k/include/asm/ide.h fix for nommu
* 'merge-devicetree' of git://git.secretlab.ca/git/linux-2.6:
spi.h: missing kernel-doc notation, please fix
of: fix missing headers for of_address_to_resource() in MTD and SysACE drivers
of: Fix missing includes
ata: update for of_device to platform_device replacement
microblaze: Fix of: eliminate of_device->node and dev_archdata->{of,prom}_node
microblaze: Fix of/address: Merge all of the bus translation code
booting-without-of: Remove nonexistent chapters from TOC, fix numbering
This patch fixes machine crashes which occur when heavily exercising the
CPU hotplug codepaths on a 32-bit kernel. These crashes are caused by
AMD Erratum 383 and result in a fatal machine check exception. Here's
the scenario:
1. On 32-bit, the swapper_pg_dir page table is used as the initial page
table for booting a secondary CPU.
2. To make this work, swapper_pg_dir needs a direct mapping of physical
memory in it (the low mappings). By adding those low, large page (2M)
mappings (PAE kernel), we create the necessary conditions for Erratum
383 to occur.
3. Other CPUs which do not participate in the off- and onlining game may
use swapper_pg_dir while the low mappings are present (when leave_mm is
called). For all steps below, the CPU referred to is a CPU that is using
swapper_pg_dir, and not the CPU which is being onlined.
4. The presence of the low mappings in swapper_pg_dir can result
in TLB entries for addresses below __PAGE_OFFSET to be established
speculatively. These TLB entries are marked global and large.
5. When the CPU with such TLB entry switches to another page table, this
TLB entry remains because it is global.
6. The process then generates an access to an address covered by the
above TLB entry but there is a permission mismatch - the TLB entry
covers a large global page not accessible to userspace.
7. Due to this permission mismatch a new 4kb, user TLB entry gets
established. Further, Erratum 383 provides for a small window of time
where both TLB entries are present. This results in an uncorrectable
machine check exception signalling a TLB multimatch which panics the
machine.
There are two ways to fix this issue:
1. Always do a global TLB flush when a new cr3 is loaded and the
old page table was swapper_pg_dir. I consider this a hack hard
to understand and with performance implications
2. Do not use swapper_pg_dir to boot secondary CPUs like 64-bit
does.
This patch implements solution 2. It introduces a trampoline_pg_dir
which has the same layout as swapper_pg_dir with low_mappings. This page
table is used as the initial page table of the booting CPU. Later in the
bringup process, it switches to swapper_pg_dir and does a global TLB
flush. This fixes the crashes in our test cases.
-v2: switch to swapper_pg_dir right after entering start_secondary() so
that we are able to access percpu data which might not be mapped in the
trampoline page table.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
LKML-Reference: <20100816123833.GB28147@aftab>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
A bug in the family-model-stepping matching code caused the presence of
errata to go undetected when OSVW was not used. This causes hangs on
some K8 systems because the E400 workaround is not enabled.
Signed-off-by: Hans Rosenfeld <hans.rosenfeld@amd.com>
LKML-Reference: <1282141190-930137-1-git-send-email-hans.rosenfeld@amd.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Fix the Errata AAK100/AAP53/BD53 workaround, the officialy documented
workaround we implemented in:
11164cd: perf, x86: Add Nehelem PMU programming errata workaround
doesn't actually work fully and causes a stuck PMU state
under load and non-functioning perf profiling.
A functional workaround was found by trial & error.
Affects all Nehalem-class Intel PMUs.
Signed-off-by: Zhang Yanmin <yanmin_zhang@linux.intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1281073148.2125.63.camel@ymzhang.sh.intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <stable@kernel.org> # .35.x
Signed-off-by: Ingo Molnar <mingo@elte.hu>
arch/m68knommu/kernel/process.c: formatting of pointers in printk()
Use %p instead of %08x in printk().
Signed-off-by: Kulikov Vasiliy <segooon@gmail.com>
Signed-off-by: Greg Ungerer <gerg@uclinux.org>
The arch/m68k/include/asm/ide.h produces errors when the IDE driver is compiled for my 523x uClinux system under kernel. The header makes some redefines of operators not defined in the arch/m68k/include/asm/io_no.h header. There are no separate mmio and iospace defines.
Signed-off-by: Jate Sujjavanich <jsujjavanich@syntech-fuelmaster.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Greg Ungerer <gerg@uclinux.org>
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb:
vt,console,kdb: preserve console_blanked while in kdb
vt: fix regression warnings from KMS merge
arm,kgdb: fix GDB_MAX_REGS no longer used
kgdb: add missing __percpu markup in arch/x86/kernel/kgdb.c
kdb: fix compile error without CONFIG_KALLSYMS
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6:
sparc64: Fix atomic64_t routine return values.
sparc64: Fix rwsem constant bug leading to hangs.
sparc: Hook up new fanotify and prlimit64 syscalls.
sparc: Really fix "console=" for serial consoles.
* master.kernel.org:/home/rmk/linux-2.6-arm:
VIDEO: amba clcd: don't disable an already disabled clock
ARM: Tighten check for allowable CPSR values
ARM: 6329/1: wire up sys_accept4() on ARM
ARM: 6328/1: Build with -fno-dwarf2-cfi-asm
ARM: 6326/1: kgdb: fix GDB_MAX_REGS no longer used
Make do_execve() take a const filename pointer so that kernel_execve() compiles
correctly on ARM:
arch/arm/kernel/sys_arm.c:88: warning: passing argument 1 of 'do_execve' discards qualifiers from pointer target type
This also requires the argv and envp arguments to be consted twice, once for
the pointer array and once for the strings the array points to. This is
because do_execve() passes a pointer to the filename (now const) to
copy_strings_kernel(). A simpler alternative would be to cast the filename
pointer in do_execve() when it's passed to copy_strings_kernel().
do_execve() may not change any of the strings it is passed as part of the argv
or envp lists as they are some of them in .rodata, so marking these strings as
const should be fine.
Further kernel_execve() and sys_execve() need to be changed to match.
This has been test built on x86_64, frv, arm and mips.
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As noticed by Linus, it is critical that some of the
rwsem constants be signed. Yet, hex constants are
unsigned unless explicitly casted or negated.
The most critical one is RWSEM_WAITING_BIAS.
This bug was exacerbated by commit
424acaaeb3 ("rwsem: wake queued readers
when writer blocks on active read lock")
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch fixes missing includes from a number of .c files because
the code (wrongfully) depended on prom.h including them. The include
of linux/of_address.h was removed in microblaze prom.h in commit
"of/address: Clean up function declarations" (sha1 id 22ae782f8), but
not fixed in some callers. This patch fixes them up.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Tested-by: Michal Simek <monstr@monstr.eu>
The only tricky bit is the compat version of fanotify_mark, which
which on 32-bit the 64-bit mark argument is passed in as "high32",
"low32".
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Darren Hart
Julia Lawall
Anton Blanchard
Denis Kirjanov
Sonny Rao
Benjamin Herrenschmidt
Linus Torvalds
Dave Kleikamp
Rupjyoti Sarmah
Ian Campbell
Mike Frysinger
Samuel Thibault
Miklos Szeredi
Kyungmin Park
Daniel Kiper
Borislav Petkov
KUMANO Syuhei
H. Peter Anvin
Tony Luck
Joerg Roedel
Hans Rosenfeld
Zhang, Yanmin
Kulikov Vasiliy
Jate Sujjavanich
David Howells
David S. Miller
Xiao Guangrong
Grant Likely