30 Oct, 2011
2 commits
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Use __force to quiet sparse warnings about user address space.
Signed-off-by: Martin Schwidefsky
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Split out addressing mode bits from PSW_BASE_BITS, rename PSW_BASE_BITS
to PSW_MASK_BASE, get rid of psw_user32_bits, remove unused function
enabled_wait(), introduce PSW_MASK_USER, and drop PSW_MASK_MERGE macros.
Change psw_kernel_bits / psw_user_bits to contain only the bits that
are always set in the respective mode.Signed-off-by: Martin Schwidefsky
24 Jul, 2011
1 commit
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The alignment is missing for various global symbols in s390 assembly code.
With a recent gcc and an instruction like stgrl this can lead to a
specification exception if the instruction uses such a mis-aligned address.Specify the alignment explicitely and while add it define __ALIGN for s390
and use the ENTRY define to save some lines of code.Signed-off-by: Jan Glauber
Signed-off-by: Martin Schwidefsky
26 May, 2011
1 commit
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Implement ndelay() on s390 as well.
Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky
11 Mar, 2011
2 commits
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Change futex_atomic_op_inuser and futex_atomic_cmpxchg_inatomic
prototypes to use u32 types for the futex as this is the data type the
futex core code uses all over the place.Signed-off-by: Michel Lespinasse
Cc: Darren Hart
Cc: Peter Zijlstra
Cc: Matt Turner
Cc: Russell King
Cc: David Howells
Cc: Tony Luck
Cc: Michal Simek
Cc: Ralf Baechle
Cc: "James E.J. Bottomley"
Cc: Benjamin Herrenschmidt
Cc: Martin Schwidefsky
Cc: Paul Mundt
Cc: "David S. Miller"
Cc: Chris Metcalf
Cc: Linus Torvalds
LKML-Reference:
Signed-off-by: Thomas Gleixner -
The cmpxchg_futex_value_locked API was funny in that it returned either
the original, user-exposed futex value OR an error code such as -EFAULT.
This was confusing at best, and could be a source of livelocks in places
that retry the cmpxchg_futex_value_locked after trying to fix the issue
by running fault_in_user_writeable().This change makes the cmpxchg_futex_value_locked API more similar to the
get_futex_value_locked one, returning an error code and updating the
original value through a reference argument.Signed-off-by: Michel Lespinasse
Acked-by: Chris Metcalf [tile]
Acked-by: Tony Luck [ia64]
Acked-by: Thomas Gleixner
Tested-by: Michal Simek [microblaze]
Acked-by: David Howells [frv]
Cc: Darren Hart
Cc: Peter Zijlstra
Cc: Matt Turner
Cc: Russell King
Cc: Ralf Baechle
Cc: "James E.J. Bottomley"
Cc: Benjamin Herrenschmidt
Cc: Martin Schwidefsky
Cc: Paul Mundt
Cc: "David S. Miller"
Cc: Linus Torvalds
LKML-Reference:
Signed-off-by: Thomas Gleixner
31 Jan, 2011
1 commit
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The uaccess functions copy_in_user_std and clear_user_std fail to
switch back from secondary space mode to primary space mode with sacf
in case of an unresolvable page fault. We need to make sure that the
switch back to primary mode is done in all cases, otherwise the code
following the uaccess inline assembly will crash.Reported-by: Alexander Graf
Signed-off-by: Martin Schwidefsky
05 Jan, 2011
1 commit
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Let local_tick_enable/disable() reprogram the clock comparator so the
function names make semantically more sense.
Also that way the functions are more symmetric since normally each
local_tick_enable() call usually would have a subsequent call to
set_clock_comparator() anyway.Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky
25 Nov, 2010
1 commit
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On each machine check all registers are revalidated. The save area for
the clock comparator however only contains the upper most seven bytes
of the former contents, if valid.
Therefore the machine check handler uses a store clock instruction to
get the current time and writes that to the clock comparator register
which in turn will generate an immediate timer interrupt.
However within the lowcore the expected time of the next timer
interrupt is stored. If the interrupt happens before that time the
handler won't be called. In turn the clock comparator won't be
reprogrammed and therefore the interrupt condition stays pending which
causes an interrupt loop until the expected time is reached.On NOHZ machines this can result in unresponsive machines since the
time of the next expected interrupted can be a couple of days in the
future.To fix this just revalidate the clock comparator register with the
expected value.
In addition the special handling for udelay must be changed as well.Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky
08 Mar, 2010
1 commit
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If there is no in kernel image caller modules will suffer:
ERROR: "copy_from_user_overflow" [net/core/pktgen.ko] undefined!
ERROR: "copy_from_user_overflow" [net/can/can-raw.ko] undefined!
ERROR: "copy_from_user_overflow" [fs/cifs/cifs.ko] undefined!Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky
27 Feb, 2010
2 commits
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This patch introduces a new function that checks the running status
of a cpu in a hypervisor. This status is not virtualized, so the check
is only correct if running in an LPAR. On acquiring a spinlock, if the
cpu holding the lock is scheduled by the hypervisor, we do a busy wait
on the lock. If it is not scheduled, we yield over to that cpu.Signed-off-by: Gerald Schaefer
Signed-off-by: Martin Schwidefsky -
Same as on x86 and sparc, besides the fact that enabling the option
will just emit compile time warnings instead of errors.
Keeps allyesconfig kernels compiling.Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky
14 Jan, 2010
1 commit
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Finally move it to the place where it belongs to and make get rid of
it for !CONFIG_SMP.Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky
15 Dec, 2009
4 commits
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Name space cleanup for rwlock functions. No functional change.
Signed-off-by: Thomas Gleixner
Acked-by: Peter Zijlstra
Acked-by: David S. Miller
Acked-by: Ingo Molnar
Cc: linux-arch@vger.kernel.org -
Not strictly necessary for -rt as -rt does not have non sleeping
rwlocks, but it's odd to not have a consistent naming convention.No functional change.
Signed-off-by: Thomas Gleixner
Acked-by: Peter Zijlstra
Acked-by: David S. Miller
Acked-by: Ingo Molnar
Cc: linux-arch@vger.kernel.org -
Name space cleanup. No functional change.
Signed-off-by: Thomas Gleixner
Acked-by: Peter Zijlstra
Acked-by: David S. Miller
Acked-by: Ingo Molnar
Cc: linux-arch@vger.kernel.org -
The raw_spin* namespace was taken by lockdep for the architecture
specific implementations. raw_spin_* would be the ideal name space for
the spinlocks which are not converted to sleeping locks in preempt-rt.Linus suggested to convert the raw_ to arch_ locks and cleanup the
name space instead of using an artifical name like core_spin,
atomic_spin or whateverNo functional change.
Signed-off-by: Thomas Gleixner
Acked-by: Peter Zijlstra
Acked-by: David S. Miller
Acked-by: Ingo Molnar
Cc: linux-arch@vger.kernel.org
07 Dec, 2009
2 commits
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The pagetable walk usercopy functions have used a modified copy of the
do_exception() function for fault handling. This lead to inconsistencies
with recent changes to do_exception(), e.g. performance counters. This
patch changes the pagetable walk usercopy code to call do_exception()
directly, eliminating the redundancy. A new parameter is added to
do_exception() to specify the fault address.Signed-off-by: Gerald Schaefer
Signed-off-by: Martin Schwidefsky -
Introduce user_mode to replace the two variables switch_amode and
s390_noexec. There are three valid combinations of the old values:
1) switch_amode == 0 && s390_noexec == 0
2) switch_amode == 1 && s390_noexec == 0
3) switch_amode == 1 && s390_noexec == 1
They get replaced by
1) user_mode == HOME_SPACE_MODE
2) user_mode == PRIMARY_SPACE_MODE
3) user_mode == SECONDARY_SPACE_MODE
The new kernel parameter user_mode=[primary,secondary,home] lets
you choose the address space mode the user space processes should
use. In addition the CONFIG_S390_SWITCH_AMODE config option
is removed.Signed-off-by: Martin Schwidefsky
06 Oct, 2009
3 commits
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This patch adds an EX_TABLE entry to mvc{p|s|os} usercopy functions that
may be called with KERNEL_DS. In combination with collaborative memory
management, kernel pages marked as unused may trigger an adressing exception
in the usercopy functions. This fixes an unhandled addressing exception bug
where strncpy_from_user() is used with len > strnlen and KERNEL_DS, crossing
a page boundary to an unused page.Signed-off-by: Gerald Schaefer
Signed-off-by: Martin Schwidefsky -
Use an own implementation instead of the common code udelay loop.
Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky -
When udelay() gets called with a delay that would expire before the
next clock event it reprograms the clock comparator.
When the interrupt happens the clock comparator won't be resetted
therefore the interrupt condition doesn't get cleared.
The result is an endless timer interrupt loop until the next clock
event would expire (stored in lowcore).
So udelay() usually would wait much longer for small delays than it
should.Fix this by disabling the local tick which makes sure that the clock
comparator will be resetted when a timer interrupt happens.Signed-off-by: Christian Borntraeger
Signed-off-by: Martin Schwidefsky
07 Jul, 2009
2 commits
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Provide __ucmpdi2() helper function on 31 bit so we don't run
again and again in compile errors like this one:kernel/built-in.o: In function `T.689':
perf_counter.c:(.text+0x56c86): undefined reference to `__ucmpdi2'Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky -
Our udelay implementation enables interrupts to receive a special timer
interrupt regardless of the context it is called from.
This might lead to false positive lockdep reports. Since lockdep isn't
aware of the fact that only a single interrupt source is enabled it
warns about possible deadlocks that in reality won't happen, like
the one below.
To fix this disable lockdep before enabling interrupts.[ 254.040888] =================================
[ 254.040904] [ INFO: inconsistent lock state ]
[ 254.040910] 2.6.30 #9
[ 254.040914] ---------------------------------
[ 254.040920] inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
[ 254.040927] swapper/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
[ 254.040934] (sch->lock){?.-...}, at: [] ccw_device_timeout+0x48/0x2f0
[ 254.040961] {IN-HARDIRQ-W} state was registered at:
[ 254.040969] [] __lock_acquire+0x9d4/0x188c
[ 254.040985] [] lock_acquire+0x13c/0x16c
[ 254.040998] [] _spin_lock+0x74/0xb8
[ 254.041016] [] do_IRQ+0xde/0x208
[ 254.041031] [] io_return+0x0/0x8
[ 254.041049] [] vtime_stop_cpu+0xbe/0x114
[ 254.041066] irq event stamp: 259629
[ 254.041076] hardirqs last enabled at (259628): [] _spin_unlock_irq+0x5e/0x9c
[ 254.041095] hardirqs last disabled at (259629): [] _spin_lock_irq+0x4a/0xc4
[ 254.041126] softirqs last enabled at (259614): [] __do_softirq+0x296/0x2b0
[ 254.041137] softirqs last disabled at (259619): [] do_softirq+0x102/0x108
[ 254.041147]
[ 254.041148] other info that might help us debug this:
[ 254.041153] 2 locks held by swapper/0:
[ 254.041157] #0: (&priv->timer){+.-...}, at: [] run_timer_softirq+0x19a/0x340
[ 254.041170] #1: (sch->lock){?.-...}, at: [] ccw_device_timeout+0x48/0x2f0
[ 254.041182]
[ 254.041310] Call Trace:
[ 254.041313] ([] show_trace+0x16c/0x170)
[ 254.041321] [] show_stack+0x78/0x104
[ 254.041327] [] dump_stack+0xc6/0xd4
[ 254.041342] [] print_usage_bug+0x1c8/0x1fc
[ 254.041353] [] mark_lock+0x4a2/0x670
[ 254.041364] [] mark_held_locks+0x8a/0xb4
[ 254.041375] [] trace_hardirqs_on_caller+0x74/0x1ac
[ 254.041388] [] trace_hardirqs_on+0x2a/0x38
[ 254.041402] [] __udelay_disabled+0xac/0xfc
[ 254.041419] [] __udelay+0x12a/0x148
[ 254.041433] [] cio_commit_config+0x170/0x290
[ 254.041451] [] cio_disable_subchannel+0x120/0x1cc
[ 254.041468] [] ccw_device_recog_done+0x54/0x2f4
[ 254.041485] [] ccw_device_sense_id_done+0x50/0x90
[ 254.041508] [] snsid_callback+0xfa/0x3a8
[ 254.041515] [] ccwreq_stop+0x80/0x90
[ 254.041523] [] ccw_request_timeout+0xc2/0xd0
[ 254.041530] [] ccw_device_request_event+0x58/0x90
[ 254.041537] [] ccw_device_timeout+0x7e/0x2f0
[ 254.041555] [] run_timer_softirq+0x22a/0x340
[ 254.041566] [] __do_softirq+0x138/0x2b0
[ 254.041578] [] do_softirq+0x102/0x108
[ 254.041590] [] irq_exit+0xee/0x114
[ 254.041603] [] do_extint+0x130/0x17c
[ 254.041617] [] ext_no_vtime+0x1e/0x22
[ 254.041631] [] vtime_stop_cpu+0xbe/0x114
[ 254.041646] ([] vtime_stop_cpu+0x6c/0x114)
[ 254.041662] [] cpu_idle+0x122/0x1c0
[ 254.041679] [] start_secondary+0xce/0xe0
[ 254.041696] [] 0x0
[ 254.041715] [] 0x0
[ 254.041745] INFO: lockdep is turned off.Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky
22 Jun, 2009
1 commit
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This allows the callers to now pass down the full set of FAULT_FLAG_xyz
flags to handle_mm_fault(). All callers have been (mechanically)
converted to the new calling convention, there's almost certainly room
for architectures to clean up their code and then add FAULT_FLAG_RETRY
when that support is added.Signed-off-by: Linus Torvalds
12 Jun, 2009
1 commit
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arch backend for f5f7eac41db827a47b2163330eecd7bb55ae9f12
"Allow rwlocks to re-enable interrupts".Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky
26 Mar, 2009
2 commits
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Use builtin variants if gcc 4 or newer is used to compile the kernel.
Generates better code than the asm variants.Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky -
Move all EXPORT_SYMBOLs to their corresponding definitions.
Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky
18 Mar, 2009
2 commits
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pfn_valid() actually checks for a valid struct page and not for a
valid pfn. Using xip mappings w/o struct pages, this will result in
-EFAULT returned by the (page table walk) user copy functions,
even though there is valid memory. Those user copy functions don't
need a struct page, so this patch just removes the pfn_valid() check.Signed-off-by: Gerald Schaefer
Signed-off-by: Martin Schwidefsky -
The implementation of __div64_31 for G5 machines is broken. The comments
in __div64_31 are correct, only the code does not do what the comments
say. The part "If the remainder has overflown subtract base and increase
the quotient" is only partially realized, the base is subtracted correctly
but the quotient is only increased if the dividend had the last bit set.
Using the correct instruction fixes the problem.Cc: stable@kernel.org
Reported-by: Frans Pop
Tested-by: Frans Pop
Signed-off-by: Martin Schwidefsky
11 Oct, 2008
1 commit
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Move cio's private simple udelay function to lib/delay.c and turn it
into something much more readable. So we have all implementations
at one place.Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky
04 Oct, 2008
1 commit
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This fixes a regression that came with 934b2857cc576ae53c92a66e63fce7ddcfa74691
("[S390] nohz/sclp: disable timer on synchronous waits.").
If udelay() gets called from a disabled context it sets the clock comparator
to a value where it expects the next interrupt. When the interrupt happens
the clock comparator gets not reset and therefore the interrupt condition
doesn't get cleared. The result is an endless timer interrupt loop.In addition this patch fixes also the following:
rcutorture reveals that our __udelay implementation is still buggy,
since it might schedule tasklets, but prevents their execution:NOHZ: local_softirq_pending 42
NOHZ: local_softirq_pending 02
NOHZ: local_softirq_pending 142
NOHZ: local_softirq_pending 02To fix this we make sure that only the clock comparator interrupt
is enabled when the enabled wait psw is loaded.
Also no code gets called anymore which might schedule tasklets.Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky
01 Aug, 2008
1 commit
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sclp_sync_wait wait synchronously for an sclp interrupt and disables
timer interrupts. However on the irq enter paths there is an extra
check if a timer interrupt would be due and calls the timer callback.
This would schedule softirqs in the wrong context.
So introduce local_tick_enable/disable which prevents this.Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky
30 Apr, 2008
2 commits
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arch/s390/lib/uaccess_mvcos.c:166:
warning: 'strnlen_user_mvcos' defined but not used
arch/s390/lib/uaccess_mvcos.c:186:
warning: 'strncpy_from_user_mvcos' defined but not usedSigned-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky -
Signed-off-by: Mathieu Desnoyers
CC: Sam Ravnborg
Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky
17 Apr, 2008
2 commits
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The current uaccess page table walk code assumes at a few places that
any access is a user space access. This is not correct if somebody
has issued a set_fs(KERNEL_DS) in advance.
Add code which checks which address space we are in and with this make
sure we access the correct address space. This way we get also rid of
the dirty
if (!currrent-mm)
return -EFAULT;
hack in futex_atomic_cmpxchg_pt.Signed-off-by: Martin Schwidefsky
Signed-off-by: Heiko Carstens -
This way we get rid of s390's NO_IDLE_HZ and use the generic dynticks
variant instead. In addition we get high resolution timers for free.Signed-off-by: Martin Schwidefsky
Signed-off-by: Heiko Carstens
21 Mar, 2008
1 commit
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a0c1e9073ef7428a14309cba010633a6cd6719ea "futex: runtime enable pi and
robust functionality" introduces a test wether futex in atomic stuff
works or not.
It does that by writing to address 0 of the kernel address space. This
will crash on older machines where addressing mode switching is enabled
but where the mvcos instruction is not available. Page table walking is
done by hand and therefore the code tries to access current->mm which
is NULL.
Therefore add an extra check, so we survive the early test.Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky
19 Feb, 2008
1 commit
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Add missing exception table entry so that the kernel can handle
proctection exceptions as well on the cs instruction. Currently only
specification exceptions are handled correctly.
The missing entry allows user space to crash the kernel.Cc: stable
Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky
26 Jan, 2008
1 commit
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In s390's spin_lock_irqsave, interrupts remain disabled while
spinning. In other architectures like x86 and powerpc, interrupts are
re-enabled while spinning if IRQ is not masked before spin_lock_irqsave
is called.The following patch re-enables interrupts through local_irq_restore
while spinning for a lock acquisition.
This can improve system response.[heiko.carstens@de.ibm.com: removed saving of pc]
Signed-off-by: Hisashi Hifumi
Signed-off-by: Heiko Carstens
Signed-off-by: Martin Schwidefsky
