fork on UML has always somewhat subtle. The underlying cause has been the
need to initialize a stack for the new process. The only portable way to
initialize a new stack is to set it as the alternate signal stack and take a
signal. The signal handler does whatever initialization is needed and jumps
back to the original stack, where the fork processing is finished. The basic
context switching mechanism is a jmp_buf for each process. You switch to a
new process by longjmping to its jmp_buf.
Now that UML has its own implementation of setjmp and longjmp, and I can poke
around inside a jmp_buf without fear that libc will change the structure, a
much simpler mechanism is possible. The jmpbuf can simply be initialized by
hand.
This eliminates -
the need to set up and remove the alternate signal stack
sending and handling a signal
the signal blocking needed around the stack switching, since
there is no stack switching
setting up the jmp_buf needed to jump back to the original
stack after the new one is set up
In addition, since jmp_buf is now defined by UML, and not by libc, it can be
embedded in the thread struct. This makes it unnecessary to have it exist on
the stack, where it used to be. It also simplifies interfaces, since the
switch jmp_buf used to be a void * inside the thread struct, and functions
which took it as an argument needed to define a jmp_buf variable and assign it
from the void *.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Mark a symbol and file as being tt-mode only. This shrinks the binary
slightly when tt mode support is compiled out and makes it easier to identity
stuff when tt mode is removed.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
BB noticed that we had the wrong bus error handler.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Make __bb_init_func weak in order to avoid a link failure with some libcs
and/or gccs.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The UML/x86_64 headers were missing ptrace support for some segment registers.
The underlying problem was that the x86_64 kernel uses user_regs_struct
rather than the ptrace register definitions in ptrace. This patch switches
UML/x86_64 to using user_regs_struct for its definitions of the host's
registers.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
ZONE_DMA might become dependent on CONFIG_ZONE_DMA, which UML doesn't define
(we're still arguing about this) So, let's change ZONE_DMA to ZONE_NORMAL.
This is prompted by optional-zone_dma-in-the-vm.patch, but should be harmless
on its own.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Make lots of structures const in order to make it obvious that they need no
locking.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This spinlock can be taken on interrupt too, so spin_lock_irq[save] must be
used.
However, Documentation/networking/netdevices.txt explains we are called with
rtnl_lock() held - so we don't need to care about other concurrent opens.
Verified also in LDD3 and by direct checking. Also verified that the network
layer (through a state machine) guarantees us that nobody will close the
interface while it's being used. Please correct me if I'm wrong.
Also, we must check we don't sleep with irqs disabled!!! But anyway, this is
not news - we already can't sleep while holding a spinlock. Who says this is
guaranted really by the present code?
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We have never used this flag and recently one user experienced a complaining
warning about this (there was a symbol in the positive half of the address space
IIRC). So fix it.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Arch-independent zone-sizing determines the size of a node
(pgdat->node_spanned_pages) based on the physical memory that was
registered by the architecture. However, when
CONFIG_MEMORY_HOTPLUG_RESERVE is set, the architecture expects that the
spanned_pages will be much larger and that mem_map will be allocated that
is used lated on memory hot-add.
This patch allows an architecture that sets CONFIG_MEMORY_HOTPLUG_RESERVE
to call push_node_boundaries() which will set the node beginning and end to
at *least* the requested boundary.
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Andi Kleen <ak@muc.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "Keith Mannthey" <kmannth@gmail.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
absent_pages_in_range() made the assumption that users of the API would not
care about holes beyound the end of physical memory. This was not the
case. This patch will account for ranges outside of physical memory as
holes correctly.
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Andi Kleen <ak@muc.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "Keith Mannthey" <kmannth@gmail.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The x86_64 code accounted for memmap and some portions of the the DMA zone as
holes. This was because those areas would never be reclaimed and accounting
for them as memory affects min watermarks. This patch will account for the
memmap as a memory hole. Architectures may optionally use set_dma_reserve()
if they wish to account for a portion of memory in ZONE_DMA as a hole.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Andi Kleen <ak@muc.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "Keith Mannthey" <kmannth@gmail.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix build error introduced by 3212fe1594
Non-NUMA case should be handled.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Since do_bad_area() always takes the currently active task and
(supposed to) take the currently active MM, there's no point passing
them to this function. Instead, obtain references to them inside
do_bad_area().
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
mm-armv.c now only contains the pgd allocation/freeing code, so
rename it to have a more sensible filename.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
If we're going to have mmu.c for code which is specific to the MMU
machines, we might as well move the other MMU initialisation
specific code from mm-armv.c into this new file. This also allows
us to make some functions static.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
There's no point to rewrite some logic to parse command line
to pass initrd parameters or to declare a user memory area.
We could use instead parse_early_param() that does the same
thing.
Signed-off-by: Franck Bui-Huu <vagabon.xyz@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
There's no point to inline any functions in setup.c. Let's GCC
doing its job, it's good enough for that now.
Signed-off-by: Franck Bui-Huu <vagabon.xyz@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This function although doing simple thing is hard to follow. It's
mainly due to:
- a lot of #ifdef
- bad local names
- redundant tests
So this patch try to address these issues. It also do not use
max_pfn global which is marked as an unused exported symbol.
As a bonus side, it's now really easy to see what part of the
code is for no-numa system.
There's also no point to make this function inline.
Signed-off-by: Franck Bui-Huu <vagabon.xyz@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This array was used to 'cache' some frame info about scheduler
functions to speed up get_wchan(). This array was 1Ko size and
was only used when CONFIG_KALLSYMS was set but declared for all
configs.
Rather than make the array statement conditional, this patches
removes this array and its uses. Indeed the common case doesn't
seem to use this array and get_wchan() is not a critical path
anyways.
It results in a smaller bss and a smaller/cleaner code:
text data bss dec hex filename
2543808 254148 139296 2937252 2cd1a4 vmlinux-new-get-wchan
2544080 254148 143392 2941620 2ce2b4 vmlinux~old
Signed-off-by: Franck Bui-Huu <vagabon.xyz@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This patch adds 2 sanity checks.
The first one test that the start address of the function to analyze has been
set by the caller. If not return an error since nothing usefull can be done
without.
The second one checks that the function's size has been set. A null size can
happen if CONFIG_KALLSYMS is not set and it means that we don't know the size
of the function to analyze. In this case, we make it equal to 128 instructions
by default.
Signed-off-by: Franck Bui-Huu <vagabon.xyz@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
While working on a glibc patch to support the fstatat() functions[1],
I noticed that the o32 implementation behaves differently on 32-bit and
64-bit kernels; the former provides a stat64 while the latter provides
a plain (o32) stat. I think the former is what's intended, as there is
no separate fstatat64. It's also what x86 does.
I think this is just a case of a compat too far.
[1] I've seen Khem's patch, but I don't think it's right.
Signed-off-by: Richard Sandiford <richard@codesourcery.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This patch introduces a number of configuration variables. These allow to
specify presence/absence of integrated peripherals found on the MIPS
RM9xxx processor family, based on the particular processor model used.
Signed-off-by: Thomas Koeller <thomas.koeller@baslerweb.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
excite_fpga.h, like all platform headers, really belongs in the
platform header directory.
Signed-off-by: Thomas Koeller <thomas.koeller@baslerweb.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The excite platform exports hardware resources for device drivers to use.
Any driver wanting to use these resources will look up them by their names.
Since these resources are declared to have static linkage, but are not
used in the source file defining them, the compiler used to emit an
'unused' warning, which this patch suppresses.
Signed-off-by: Thomas Koeller <thomas.koeller@baslerweb.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
With more recent compilers inline doesn't necessarily means a function
will always be inlined. So leave that decission to the compiler and
make the function as __init.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The following change updates the Atlas interrupt handling to match that
of Malta. Tested with a 5Kc and a 34Kf successfully.
Signed-off-by: Maciej W. Rozycki <macro@mips.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
In hooking up the perf counter overflow interrupt to the experimental
deprecated-real-soon-now /proc/perf interface last night, I had to
revisit arch/mips/mips-boards/generic/time.c, and discovered that
when the 2.6.9-based SMTC prototype was merged with the more
recent tree, it was missed that arch/mips/kernel/time.c had changed
so that even in SMP kernels, timer_interrupt() calls
local_timer_interrupt(), so there is no longer a need to invoke it
directly from mips_timer_interrupt() in those cases where
timer_interrupt() has been called. So I got rid of that, and added the
invocation of perf_irq() if Cause.PCI is set, more-or-less following the
same logic as in the non-SMTC case, with the modifications that (a) a
runtime check for Release 2 isn't done, because it's redundant in SMTC),
and (b) we check for a clock interrupt regardless of the value returned
by the perf counter service - I don't understand why we'd want to control
that with perf_irq(), but maybe one of you knows the story. I also got
rid of the stupid warning about the unused variable when compiled for
SMTC (another artifact of the merge). The result hasn't been beaten to
death, but boots, seems stable, and supports extended precision event
counting.
Signed-off-by: Kevin D. Kissell <kevink@mips.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
If a thread became runnable between need_resched() and the WAIT
instruction, switching to the thread will delay until a next interrupt.
Some CPUs can execute the WAIT instruction with interrupt disabled, so
we can get rid of this race on them (at least UP case).
Original Patch by Atsushi with fixing up for MIPS Technology's cores by
Ralf based on feedback from the RTL designers.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Jeff Dike