The discussion about using "access_ok()" in get_user_pages_fast() (see
commit 7f81890687: "x86: don't use
'access_ok()' as a range check in get_user_pages_fast()" for details and
end result), made us notice that x86-64 was really being very sloppy
about virtual address checking.
So be way more careful and straightforward about masking x86-64 virtual
addresses:
- All the VIRTUAL_MASK* variants now cover half of the address
space, it's not like we can use the full mask on a signed
integer, and the larger mask just invites mistakes when
applying it to either half of the 48-bit address space.
- /proc/kcore's kc_offset_to_vaddr() becomes a lot more
obvious when it transforms a file offset into a
(kernel-half) virtual address.
- Unify/simplify the 32-bit and 64-bit USER_DS definition to
be based on TASK_SIZE_MAX.
This cleanup and more careful/obvious user virtual address checking also
uncovered a buglet in the x86-64 implementation of strnlen_user(): it
would do an "access_ok()" check on the whole potential area, even if the
string itself was much shorter, and thus return an error even for valid
strings. Our sloppy checking had hidden this.
So this fixes 'strnlen_user()' to do this properly, the same way we
already handled user strings in 'strncpy_from_user()'. Namely by just
checking the first byte, and then relying on fault handling for the
rest. That always works, since we impose a guard page that cannot be
mapped at the end of the user space address space (and even if we
didn't, we'd have the address space hole).
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'perfcounters-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (49 commits)
perfcounter: Handle some IO return values
perf_counter: Push perf_sample_data through the swcounter code
perf_counter tools: Define and use our own u64, s64 etc. definitions
perf_counter: Close race in perf_lock_task_context()
perf_counter, x86: Improve interactions with fast-gup
perf_counter: Simplify and fix task migration counting
perf_counter tools: Add a data file header
perf_counter: Update userspace callchain sampling uses
perf_counter: Make callchain samples extensible
perf report: Filter to parent set by default
perf_counter tools: Handle lost events
perf_counter: Add event overlow handling
fs: Provide empty .set_page_dirty() aop for anon inodes
perf_counter: tools: Makefile tweaks for 64-bit powerpc
perf_counter: powerpc: Add processor back-end for MPC7450 family
perf_counter: powerpc: Make powerpc perf_counter code safe for 32-bit kernels
perf_counter: powerpc: Change how processor-specific back-ends get selected
perf_counter: powerpc: Use unsigned long for register and constraint values
perf_counter: powerpc: Enable use of software counters on 32-bit powerpc
perf_counter tools: Add and use isprint()
...
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched: Fix out of scope variable access in sched_slice()
sched: Hide runqueues from direct refer at source code level
sched: Remove unneeded __ref tag
sched, x86: Fix cpufreq + sched_clock() TSC scaling
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (24 commits)
tracing/urgent: warn in case of ftrace_start_up inbalance
tracing/urgent: fix unbalanced ftrace_start_up
function-graph: add stack frame test
function-graph: disable when both x86_32 and optimize for size are configured
ring-buffer: have benchmark test print to trace buffer
ring-buffer: do not grab locks in nmi
ring-buffer: add locks around rb_per_cpu_empty
ring-buffer: check for less than two in size allocation
ring-buffer: remove useless compile check for buffer_page size
ring-buffer: remove useless warn on check
ring-buffer: use BUF_PAGE_HDR_SIZE in calculating index
tracing: update sample event documentation
tracing/filters: fix race between filter setting and module unload
tracing/filters: free filter_string in destroy_preds()
ring-buffer: use commit counters for commit pointer accounting
ring-buffer: remove unused variable
ring-buffer: have benchmark test handle discarded events
ring-buffer: prevent adding write in discarded area
tracing/filters: strloc should be unsigned short
tracing/filters: operand can be negative
...
Fix up kmemcheck-induced conflict in kernel/trace/ring_buffer.c manually
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (45 commits)
x86, mce: fix error path in mce_create_device()
x86: use zalloc_cpumask_var for mce_dev_initialized
x86: fix duplicated sysfs attribute
x86: de-assembler-ize asm/desc.h
i386: fix/simplify espfix stack switching, move it into assembly
i386: fix return to 16-bit stack from NMI handler
x86, ioapic: Don't call disconnect_bsp_APIC if no APIC present
x86: Remove duplicated #include's
x86: msr.h linux/types.h is only required for __KERNEL__
x86: nmi: Add Intel processor 0x6f4 to NMI perfctr1 workaround
x86, mce: mce_intel.c needs <asm/apic.h>
x86: apic/io_apic.c: dmar_msi_type should be static
x86, io_apic.c: Work around compiler warning
x86: mce: Don't touch THERMAL_APIC_VECTOR if no active APIC present
x86: mce: Handle banks == 0 case in K7 quirk
x86, boot: use .code16gcc instead of .code16
x86: correct the conversion of EFI memory types
x86: cap iomem_resource to addressable physical memory
x86, mce: rename _64.c files which are no longer 64-bit-specific
x86, mce: mce.h cleanup
...
Manually fix up trivial conflict in arch/x86/mm/fault.c
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (35 commits)
Input: add driver for Synaptics I2C touchpad
Input: synaptics - add support for reporting x/y resolution
Input: ALPS - handle touchpoints buttons correctly
Input: gpio-keys - change timer to workqueue
Input: ads7846 - pin change interrupt support
Input: add support for touchscreen on W90P910 ARM platform
Input: appletouch - improve finger detection
Input: wacom - clear Intuos4 wheel data when finger leaves proximity
Input: ucb1400 - move static function from header into core
Input: add driver for EETI touchpanels
Input: ads7846 - more detailed model name in sysfs
Input: ads7846 - support swapping x and y axes
Input: ati_remote2 - use non-atomic bitops
Input: introduce lm8323 keypad driver
Input: psmouse - ESD workaround fix for OLPC XO touchpad
Input: tsc2007 - make sure platform provides get_pendown_state()
Input: uinput - flush all pending ff effects before destroying device
Input: simplify name handling for certain input handles
Input: serio - do not use deprecated dev.power.power_state
Input: wacom - add support for Intuos4 tablets
...
It's really not right to use 'access_ok()', since that is meant for the
normal "get_user()" and "copy_from/to_user()" accesses, which are done
through the TLB, rather than through the page tables.
Why? access_ok() does both too few, and too many checks. Too many,
because it is meant for regular kernel accesses that will not honor the
'user' bit in the page tables, and because it honors the USER_DS vs
KERNEL_DS distinction that we shouldn't care about in GUP. And too few,
because it doesn't do the 'canonical' check on the address on x86-64,
since the TLB will do that for us.
So instead of using a function that isn't meant for this, and does
something else and much more complicated, just do the real rules: we
don't want the range to overflow, and on x86-64, we want it to be a
canonical low address (on 32-bit, all addresses are canonical).
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit b99b87f70c add CONSTRUCTOR
support to Linux but Microblaze not defined KERNEL_CTORS symbols
which are used with that patch.
This patch fixed it.
Signed-off-by: Michal Simek <monstr@monstr.eu>
Alexey removed the definition for init_mm from all architectures
but forgot microblaze, which was only recently added.
This fixes the microblaze build by dropping it there as well.
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michal Simek <monstr@monstr.eu>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/vapier/blackfin:
Blackfin: convert page/tlb to asm-generic
Blackfin: convert types to asm-generic
Blackfin: convert irq/process to asm-generic
Blackfin: convert signal/mmap to asm-generic
Blackfin: convert locking primitives to asm-generic
Blackfin: convert termios to asm-generic
Blackfin: convert simple headers to asm-generic
Blackfin: convert socket/poll to asm-generic
Blackfin: convert user/elf to asm-generic
Blackfin: convert shm/sysv/ipc to asm-generic
Blackfin: convert asm/ioctls.h to asm-generic/ioctls.h
Blackfin: only build irqpanic.c when needed
Blackfin: pull in asm/io.h in ksyms for prototypes
Blackfin: use common test_bit() rather than __test_bit()
This patch adds spi and mmc-spi-slot nodes, plus a gpio-controller for
PIXIS' sdcsr bank that is used for managing SPI chip-select and for
reading card's states.
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Cc: Kumar Gala <galak@gate.crashing.org>
Cc: David Brownell <david-b@pacbell.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Improve a few details in perfcounter call-chain recording that
makes use of fast-GUP:
- Use ACCESS_ONCE() to observe the pte value. ptes are fundamentally
racy and can be changed on another CPU, so we have to be careful
about how we access them. The PAE branch is already careful with
read-barriers - but the non-PAE and 64-bit side needs an
ACCESS_ONCE() to make sure the pte value is observed only once.
- make the checks a bit stricter so that we can feed it any kind of
cra^H^H^H user-space input ;-)
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Before exposing upstream tools to a callchain-samples ABI, tidy it
up to make it more extensible in the future:
Use markers in the IP chain to denote context, use (u64)-1..-4095 range
for these context markers because we use them for ERR_PTR(), so these
addresses are unlikely to be mapped.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Commit b696fdc259 ("sparc64: Defer
cpu_data() setup until end of per-cpu data initialization.") broke
bootup for UP builds because the cpu_data() initialization only
occurs in setup_per_cpu_areas() which is never compiled in nor
called in UP builds.
Fix this up by calling the setups directly from init_64.c when
non-SMP.
Reported-by: Alexander Beregalov <a.beregalov@gmail.com>
Tested-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The irq_panic function is only used when CONFIG_DEBUG_ICACHE_CHECK is
enabled, so move the conditional build to the Makefile rather than
wrapping all of the contents of the file.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Make sure we pull in asm/io.h when exporting symbols for the I/O functions
so we don't end up with a build failure due to missing prototypes.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Convert to test_bit() as that is what pretty much everyone uses and allows
us to migrate asm/bitops.h to the asm-generic version.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
In case gcc does something funny with the stack frames, or the return
from function code, we would like to detect that.
An arch may implement passing of a variable that is unique to the
function and can be saved on entering a function and can be tested
when exiting the function. Usually the frame pointer can be used for
this purpose.
This patch also implements this for x86. Where it passes in the stack
frame of the parent function, and will test that frame on exit.
There was a case in x86_32 with optimize for size (-Os) where, for a
few functions, gcc would align the stack frame and place a copy of the
return address into it. The function graph tracer modified the copy and
not the actual return address. On return from the funtion, it did not go
to the tracer hook, but returned to the parent. This broke the function
graph tracer, because the return of the parent (where gcc did not do
this funky manipulation) returned to the location that the child function
was suppose to. This caused strange kernel crashes.
This test detected the problem and pointed out where the issue was.
This modifies the parameters of one of the functions that the arch
specific code calls, so it includes changes to arch code to accommodate
the new prototype.
Note, I notice that the parsic arch implements its own push_return_trace.
This is now a generic function and the ftrace_push_return_trace should be
used instead. This patch does not touch that code.
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6: (56 commits)
sh: Fix declaration of __kernel_sigreturn and __kernel_rt_sigreturn
sh: Enable soc-camera in ap325rxa/migor/se7724 defconfigs.
sh: remove stray markers.
sh: defconfig updates.
sh: pci: Initial PCI-Express support for SH7786 Urquell board.
sh: Generic HAVE_PERF_COUNTER support.
SH: convert migor to soc-camera as platform-device
SH: convert ap325rxa to soc-camera as platform-device
soc-camera: unify i2c camera device platform data
sh: add platform data for r8a66597-hcd in setup-sh7723
sh: add platform data for r8a66597-hcd in setup-sh7366
sh: x3proto: add platform data for r8a66597-hcd
sh: highlander: add platform data for r8a66597-hcd
sh: sh7785lcr: add platform data for r8a66597-hcd
sh: turn off irqs when disabling CMT/TMU timers
sh: use kzalloc() for cpg clocks
sh: unbreak WARN_ON()
sh: Use generic atomic64_t implementation.
sh: Revised clock function in highlander
sh: Update r7780mp defconfig
...
Add support for new relocs which may show up in MN10300 kernel modules due to
linker relaxation.
Signed-off-by: Mark Salter <msalter@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Enable gcov profiling of the entire kernel on x86_64. Required changes
include disabling profiling for:
* arch/kernel/acpi/realmode and arch/kernel/boot/compressed:
not linked to main kernel
* arch/vdso, arch/kernel/vsyscall_64 and arch/kernel/hpet:
profiling causes segfaults during boot (incompatible context)
Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Li Wei <W.Li@Sun.COM>
Cc: Michael Ellerman <michaele@au1.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Heiko Carstens <heicars2@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <mschwid2@linux.vnet.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Jeff Dike <jdike@addtoit.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>
Enable the use of GCC's coverage testing tool gcov [1] with the Linux
kernel. gcov may be useful for:
* debugging (has this code been reached at all?)
* test improvement (how do I change my test to cover these lines?)
* minimizing kernel configurations (do I need this option if the
associated code is never run?)
The profiling patch incorporates the following changes:
* change kbuild to include profiling flags
* provide functions needed by profiling code
* present profiling data as files in debugfs
Note that on some architectures, enabling gcc's profiling option
"-fprofile-arcs" for the entire kernel may trigger compile/link/
run-time problems, some of which are caused by toolchain bugs and
others which require adjustment of architecture code.
For this reason profiling the entire kernel is initially restricted
to those architectures for which it is known to work without changes.
This restriction can be lifted once an architecture has been tested
and found compatible with gcc's profiling. Profiling of single files
or directories is still available on all platforms (see config help
text).
[1] http://gcc.gnu.org/onlinedocs/gcc/Gcov.html
Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Li Wei <W.Li@Sun.COM>
Cc: Michael Ellerman <michaele@au1.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Heiko Carstens <heicars2@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <mschwid2@linux.vnet.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Jeff Dike <jdike@addtoit.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>
Fix up the number of cells for the values of CPC925 Memory Controller,
and setup related platform device during system booting up, against
which CPC925 Memory Controller EDAC driver would be matched.
Signed-off-by: Harry Ciao <qingtao.cao@windriver.com>
Cc: Doug Thompson <norsk5@yahoo.com>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Kumar Gala <galak@gate.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
m32r: PTRACE_SINGLESTEP sets PT_DTRACE, it is never used except cleared
after do_execve().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Hirokazu Takata <takata@linux-m32r.org>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
avr32, mn10300, parisc, s390, sh, xtensa:
They never set PT_DTRACE, but clear it after do_execve().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Acked-by: Kyle McMartin <kyle@mcmartin.ca>
Cc: Grant Grundler <grundler@parisc-linux.org>
Cc: Matthew Wilcox <matthew@wil.cx>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Chris Zankel <chris@zankel.net>
Acked-by: Roland McGrath <roland@redhat.com>
Acked-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
h8300 defines PT_DTRACE for asm but never uses it.
DEFINE(PT_PTRACED, PT_PTRACED) seems to be unused too.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Yoshinori Sato <ysato@users.sourceforge.jp>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
GCC 4.5.0 complains about the declaration of variables
__kernel_sigreturn and __kernel_rt_sigreturn because they have type
void. Correctly declare these symbols as functions to fix the
following error,
arch/sh/kernel/signal_32.c: In function 'setup_frame':
arch/sh/kernel/signal_32.c:368:14: error: taking address of expression of type 'void'
arch/sh/kernel/signal_32.c: In function 'setup_rt_frame':
arch/sh/kernel/signal_32.c:452:14: error: taking address of expression of type 'void'
make[1]: *** [arch/sh/kernel/signal_32.o] Error 1
make: *** [arch/sh/kernel] Error 2
Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This adds support for the performance monitor hardware on the
MPC7450 family of processors (7450, 7451, 7455, 7447/7457, 7447A,
7448), used in the later Apple G4 powermacs/powerbooks and other
machines. These machines have 6 hardware counters with a unique
set of events which can be counted on each counter, with some
events being available on multiple counters.
Raw event codes for these processors are (PMC << 8) + PMCSEL.
If PMC is non-zero then the event is that selected by the given
PMCSEL value for that PMC (hardware counter). If PMC is zero
then the event selected is one of the low-numbered ones that are
common to several PMCs. In this case PMCSEL must be <= 22 and
the event is what that PMCSEL value would select on PMC1 (but
it may be placed any other PMC that has the same event for that
PMCSEL value).
For events that count cycles or occurrences that exceed a threshold,
the threshold requested can be specified in the 0x3f000 bits of the
raw event codes. If the event uses the threshold multiplier bit
and that bit should be set, that is indicated with the 0x40000 bit
of the raw event code.
This fills in some of the generic cache events. Unfortunately there
are quite a few blank spaces in the table, partly because these
processors tend to count cache hits rather than cache accesses.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: linuxppc-dev@ozlabs.org
Cc: benh@kernel.crashing.org
LKML-Reference: <19000.55631.802122.696927@cargo.ozlabs.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This abstracts a few things in arch/powerpc/kernel/perf_counter.c
that are specific to 64-bit kernels, and provides definitions for
32-bit kernels. In particular,
* Only 64-bit has MMCRA and the bits in it that give information
about a PMU interrupt (sampled PR, HV, slot number etc.)
* Only 64-bit has the lppaca and the lppaca->pmcregs_in_use field
* Use of SDAR is confined to 64-bit for now
* Only 64-bit has soft/lazy interrupt disable and therefore
pseudo-NMIs (interrupts that occur while interrupts are soft-disabled)
* Only 64-bit has PMC7 and PMC8
* Only 64-bit has the MSR_HV bit.
This also fixes the types used in a couple of places, where we were
using long types for things that need to be 64-bit.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: linuxppc-dev@ozlabs.org
Cc: benh@kernel.crashing.org
LKML-Reference: <19000.55590.634126.876084@cargo.ozlabs.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
At present, the powerpc generic (processor-independent) perf_counter
code has list of processor back-end modules, and at initialization,
it looks at the PVR (processor version register) and has a switch
statement to select a suitable processor-specific back-end.
This is going to become inconvenient as we add more processor-specific
back-ends, so this inverts the order: now each back-end checks whether
it applies to the current processor, and registers itself if so.
Furthermore, instead of looking at the PVR, back-ends now check the
cur_cpu_spec->oprofile_cpu_type string and match on that.
Lastly, each back-end now specifies a name for itself so the core can
print a nice message when a back-end registers itself.
This doesn't provide any support for unregistering back-ends, but that
wouldn't be hard to do and would allow back-ends to be modules.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: linuxppc-dev@ozlabs.org
Cc: benh@kernel.crashing.org
LKML-Reference: <19000.55529.762227.518531@cargo.ozlabs.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
