Semaphores are no longer performance-critical, so a generic C
implementation is better for maintainability, debuggability and
extensibility. Thanks to Peter Zijlstra for fixing the lockdep
warning. Thanks to Harvey Harrison for pointing out that the
unlikely() was unnecessary.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
add_reserved_region() tries to keep the resource list sorted, so when
looking for a place to insert the new resource, it may break out
before the last entry.
When this happens, the list is broken in two because the sibling field
of the new entry doesn't point to the next resource. Fix it by
updating the new resource's sibling field appropriately.
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Don't include the BUG trap handling code when CONFIG_BUG is not set.
This fixes allnoconfig.
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Iff the parent has TIF_DEBUG set, _and_ clone_flags includes
CLONE_PTRACE we should set the TIF_DEBUG flag for the child and
increment the ocd refcount. Otherwise, the TIF_DEBUG flag must be
unset.
Currently, the child inherits TIF_DEBUG from the parent before
copy_thread is called, so TIF_DEBUG may be already be set before we
determine whether the child is supposed to inherit debugging
capabilities from the parent or not. This means that ocd_enable()
won't increment the refcount, because TIF_DEBUG is already set, and
that TIF_DEBUG will be set for processes that aren't being debugged.
This leads to a refcounting asymmetry, which may show up as
------------[ cut here ]------------
Badness at arch/avr32/kernel/ocd.c:73
PC is at ocd_disable+0x34/0x60
LR is at put_lock_stats+0xa/0x20
as reported by David Brownell. Happens when strace'ing a process that
forks a new child process, e.g. "strace mount -tjffs2 mtd1 /mnt", and
subsequently killing the child process (e.g. "umount /mnt".)
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
This fixes a hang on boot with nohz enabled. nohz is not actually
supported in mainline yet, but patches that add support for it are
currently under review.
When nohz is compiled out, the functions are no-ops, so this patch
results in no functional change, but it arguably makes the code more
correct.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Sometimes simple attributes might need to return an error, e.g. for
acquiring a mutex interruptibly. In fact we have that situation in
spufs already which is the original user of the simple attributes. This
patch merged the temporarily forked attributes in spufs back into the
main ones and allows to return errors.
[akpm@linux-foundation.org: build fix]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: <stefano.brivio@polimi.it>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg KH <greg@kroah.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patchset adds a flags variable to reserve_bootmem() and uses the
BOOTMEM_EXCLUSIVE flag in crashkernel reservation code to detect collisions
between crashkernel area and already used memory.
This patch:
Change the reserve_bootmem() function to accept a new flag BOOTMEM_EXCLUSIVE.
If that flag is set, the function returns with -EBUSY if the memory already
has been reserved in the past. This is to avoid conflicts.
Because that code runs before SMP initialisation, there's no race condition
inside reserve_bootmem_core().
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix powerpc build]
Signed-off-by: Bernhard Walle <bwalle@suse.de>
Cc: <linux-arch@vger.kernel.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch consolidate all definitions of .init.text, .init.data
and .exit.text, .exit.data section definitions in
the generic vmlinux.lds.h.
This is a preparational patch - alone it does not buy
us much good.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/hskinnemoen/avr32-2.6:
[AVR32] extint: Set initial irq type to low level
[AVR32] extint: change set_irq_type() handling
[AVR32] NMI debugging
[AVR32] constify function pointer tables
[AVR32] ATNGW100: Update defconfig
[AVR32] ATSTK1002: Update defconfig
[AVR32] Kconfig: Choose daughterboard instead of CPU
[AVR32] Add support for ATSTK1003 and ATSTK1004
[AVR32] Clean up external DAC setup code
[AVR32] ATSTK1000: Move gpio-leds setup to setup.c
[AVR32] Add support for AT32AP7001 and AT32AP7002
[AVR32] Provide more CPU information in /proc/cpuinfo and dmesg
[AVR32] Oprofile support
[AVR32] Include instrumentation menu
Disable VGA text console for AVR32 architecture
[AVR32] Enable debugging only when needed
ptrace: Call arch_ptrace_attach() when request=PTRACE_TRACEME
[AVR32] Remove redundant try_to_freeze() call from do_signal()
[AVR32] Drop GFP_COMP for DMA memory allocations
Change the NMI handler to use the die notifier chain to signal anyone
who cares. Add a simple "nmi debugger" which hooks into this chain and
that may dump registers, task state, etc. when it happens.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Add the following fields to /proc/cpuinfo:
* chip type and revision (from the JTAG chip id)
* cpu MHz (from clk_get_rate())
* features (from the CONFIG0 register)
Also rename "cpu family" to "cpu arch" and "cpu type" to "cpu core" to
remove some ambiguity.
Show chip type and revision at bootup, and clarify that the other
kinds of IDs that we're already printing are for the cpu core and
architecture. Rename "AP7000" to "AP7" since that's the name of the
core.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Keep track of processes being debugged (including the kernel itself)
and turn the OCD system on and off as appropriate. Since enabling
debugging turns off some optimizations in the CPU core, this fixes the
issue that enabling KProbes support or simply running a program under
gdbserver will reduce system performance significantly until the next
reboot.
The CPU performance will still be reduced for all processes while a
process is being debugged, but this is a lot better than reducing the
performance forever.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
get_signal_to_deliver() will call try_to_freeze(), so there's no point
in do_signal() doing it as well.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
All kobjects require a dynamically allocated name now. We no longer
need to keep track if the name is statically assigned, we can just
unconditionally free() all kobject names on cleanup.
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
It's not like it really matters at this point since the system is
dying anyway, but handle_critical pushes too few registers on the
stack so the register dump, which makes the register dump look a bit
strange. This patch fixes it.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
The current debug trap handling code does a number of things that are
illegal according to the AVR32 Architecture manual. Most importantly,
it may try to schedule from Debug Mode, thus clearing the D bit, which
can lead to "undefined behaviour".
It seems like this works in most cases, but several people have
observed somewhat unstable behaviour when debugging programs,
including soft lockups. So there's definitely something which is not
right with the existing code.
The new code will never schedule from Debug mode, it will always exit
Debug mode with a "retd" instruction, and if something not running in
Debug mode needs to do something debug-related (like doing a single
step), it will enter debug mode through a "breakpoint" instruction.
The monitor code will then return directly to user space, bypassing
its own saved registers if necessary (since we don't actually care
about the trapped context, only the one that came before.)
This adds three instructions to the common exception handling code,
including one branch. It does not touch super-hot paths like the TLB
miss handler.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Generate a new set of OCD register definitions in asm/ocd.h and rename
__mfdr() and __mtdr() to ocd_read() and ocd_write() respectively.
The bitfield definitions are a lot more complete now, and they are
entirely based on bit numbers, not masks. This is because OCD
registers are frequently accessed from assembly code, where bit
numbers are a lot more useful (can be fed directly to sbr, bfins,
etc.)
Bitfields that consist of more than one bit have two definitions:
_START, which indicates the number of the first bit, and _SIZE, which
indicates the number of bits. These directly correspond to the
parameters taken by the bfextu, bfexts and bfins instructions.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
The 'H' bit is bit 29, while the 'R' bit doesn't exist. Luckily, we
don't actually use any of the bits in question.
Also update show_regs() to show the Debug Mask and Debug state bits.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
is_init() is an ambiguous name for the pid==1 check. Split it into
is_global_init() and is_container_init().
A cgroup init has it's tsk->pid == 1.
A global init also has it's tsk->pid == 1 and it's active pid namespace
is the init_pid_ns. But rather than check the active pid namespace,
compare the task structure with 'init_pid_ns.child_reaper', which is
initialized during boot to the /sbin/init process and never changes.
Changelog:
2.6.22-rc4-mm2-pidns1:
- Use 'init_pid_ns.child_reaper' to determine if a given task is the
global init (/sbin/init) process. This would improve performance
and remove dependence on the task_pid().
2.6.21-mm2-pidns2:
- [Sukadev Bhattiprolu] Changed is_container_init() calls in {powerpc,
ppc,avr32}/traps.c for the _exception() call to is_global_init().
This way, we kill only the cgroup if the cgroup's init has a
bug rather than force a kernel panic.
[akpm@linux-foundation.org: fix comment]
[sukadev@us.ibm.com: Use is_global_init() in arch/m32r/mm/fault.c]
[bunk@stusta.de: kernel/pid.c: remove unused exports]
[sukadev@us.ibm.com: Fix capability.c to work with threaded init]
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Acked-by: Pavel Emelianov <xemul@openvz.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Herbert Poetzel <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Introduce architecture dependent kretprobe blacklists to prohibit users
from inserting return probes on the function in which kprobes can be
inserted but kretprobes can not.
This patch also removes "__kprobes" mark from "__switch_to" on x86_64 and
registers "__switch_to" to the blacklist on x86-64, because that mark is to
prohibit user from inserting only kretprobe.
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Identical handlers of PTRACE_DETACH go into ptrace_request().
Not touching compat code.
Not touching archs that don't call ptrace_request.
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__init_end, which comes immediately before .text, is already page
aligned, and that should be more than enough for the .text section.
The reason why we need to align the .text section is because the
interrupt handler offset is ORed with EVBA, so we need to provide
enough alignment of EVBA that this OR operation works as an ADD.
Currently, the last interrupt handler is not nearly a full page away
from EVBA, so it won't be a problem.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Use PAGE_SIZE, THREAD_SIZE and L1_CACHE_BYTES instead of harcoded
constants in places where that's what we really mean.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Rename vmlinux.lds to a .S file to match other architectures.
Simplify Makefile to match the rename and deleted the unused
USE_STANDARD_AS_RULE
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
This code is inside an #ifdef with a misspelled config symbol, so it
hasn't been used for a long time. Fix it before fixing the config
symbol to keep bisection working.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Identical implementations of PTRACE_POKEDATA go into generic_ptrace_pokedata()
function.
AFAICS, fix bug on xtensa where successful PTRACE_POKEDATA will nevertheless
return EPERM.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If the kernel OOPSed or BUGed then it probably should be considered as
tainted. Thus, all subsequent OOPSes and SysRq dumps will report the
tainted kernel. This saves a lot of time explaining oddities in the
calltraces.
Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ Added parisc patch from Matthew Wilson -Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The current generic bug implementation has a call to dump_stack() in case a
WARN_ON(whatever) gets hit. Since report_bug(), which calls dump_stack(),
gets called from an exception handler we can do better: just pass the
pt_regs structure to report_bug() and pass it to show_regs() in case of a
warning. This will give more debug informations like register contents,
etc... In addition this avoids some pointless lines that dump_stack()
emits, since it includes a stack backtrace of the exception handler which
is of no interest in case of a warning. E.g. on s390 the following lines
are currently always present in a stack backtrace if dump_stack() gets
called from report_bug():
[<000000000001517a>] show_trace+0x92/0xe8)
[<0000000000015270>] show_stack+0xa0/0xd0
[<00000000000152ce>] dump_stack+0x2e/0x3c
[<0000000000195450>] report_bug+0x98/0xf8
[<0000000000016cc8>] illegal_op+0x1fc/0x21c
[<00000000000227d6>] sysc_return+0x0/0x10
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Kyle McMartin <kyle@parisc-linux.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Avoid the costly notifier list in the pagefault path and call
the kprobes code directly. The same change went into the 2.6.22
cycle for powerpc, 2s390 and sparc64 already.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
The comment at the top of arch/avr32/kernel/irq.c doesn't really make
sense anymore since most of the actual interrupt handling code is
elsewhere.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Recently a few direct accesses to the thread_info in the task structure snuck
back, so this wraps them with the appropriate wrapper.
Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tested with a slightly hacked version of the test case included with
the original utimensat patch. All OK.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Rename .taglist to .taglist.init to silence section mismatch warnings.
The .taglist.init section was already placed in the .init output
section along with .init.text, so the warning didn't indicate any real
problems.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Remove includes of <linux/smp_lock.h> where it is not used/needed.
Suggested by Al Viro.
Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc,
sparc64, and arm (all 59 defconfigs).
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch moves the die notifier handling to common code. Previous
various architectures had exactly the same code for it. Note that the new
code is compiled unconditionally, this should be understood as an appel to
the other architecture maintainer to implement support for it aswell (aka
sprinkling a notify_die or two in the proper place)
arm had a notifiy_die that did something totally different, I renamed it to
arm_notify_die as part of the patch and made it static to the file it's
declared and used at. avr32 used to pass slightly less information through
this interface and I brought it into line with the other architectures.
[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: fix vmalloc_sync_all bustage]
[bryan.wu@analog.com: fix vmalloc_sync_all in nommu]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: <linux-arch@vger.kernel.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Reorder some instructions and change the register usage to reduce
the number of pipeline stalls. Also use the bfextu and bfins
instructions for bitfield manipulations instead of shifting and
masking.
This makes gzipping a 80MB file approximately 2% faster.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Since the core setup code takes care of both allocation and
reservation of framebuffer memory, there's no need for this board-
specific hook anymore. Replace it with two global variables,
fbmem_start and fbmem_size, which can be used directly.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
