Impact: x86_64 percpu area layout change, irq_stack now at the beginning
Now that the PDA is empty except for the stack canary, it can be removed.
The irqstack is moved to the start of the per-cpu section. If the stack
protector is enabled, the canary overlaps the bottom 48 bytes of the irqstack.
tj: * updated subject
* dropped asm relocation of irq_stack_ptr
* updated comments a bit
* rebased on top of stack canary changes
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Impact: cleanup
Use cpu_number to determine if the adjustment is necessary.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
[ Based on original patch from Christoph Lameter and Mike Travis. ]
As pda is now allocated in percpu area, it can easily be made a proper
percpu variable. Make it so by defining per cpu symbol from linker
script and declaring it in C code for SMP and simply defining it for
UP. This change cleans up code and brings SMP and UP closer a bit.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
[ Based on original patch from Christoph Lameter and Mike Travis. ]
Currently pdas and percpu areas are allocated separately. %gs points
to local pda and percpu area can be reached using pda->data_offset.
This patch folds pda into percpu area.
Due to strange gcc requirement, pda needs to be at the beginning of
the percpu area so that pda->stack_canary is at %gs:40. To achieve
this, a new percpu output section macro - PERCPU_VADDR_PREALLOC() - is
added and used to reserve pda sized chunk at the start of the percpu
area.
After this change, for boot cpu, %gs first points to pda in the
data.init area and later during setup_per_cpu_areas() gets updated to
point to the actual pda. This means that setup_per_cpu_areas() need
to reload %gs for CPU0 while clearing pda area for other cpus as cpu0
already has modified it when control reaches setup_per_cpu_areas().
This patch also removes now unnecessary get_local_pda() and its call
sites.
A lot of this patch is taken from Mike Travis' "x86_64: Fold pda into
per cpu area" patch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
[ Based on original patch from Christoph Lameter and Mike Travis. ]
CPU startup code in head_64.S loaded address of a zero page into %gs
for temporary use till pda is loaded but address to the actual pda is
available at the point. Load the real address directly instead.
This will help unifying percpu and pda handling later on.
This patch is mostly taken from Mike Travis' "x86_64: Fold pda into
per cpu area" patch.
Signed-off-by: Tejun Heo <tj@kernel.org>
[ Based on original patch from Christoph Lameter and Mike Travis. ]
This patch makes percpu symbols zerobased on x86_64 SMP by adding
PERCPU_VADDR() to vmlinux.lds.h which helps setting explicit vaddr on
the percpu output section and using it in vmlinux_64.lds.S. A new
PHDR is added as existing ones cannot contain sections near address
zero. PERCPU_VADDR() also adds a new symbol __per_cpu_load which
always points to the vaddr of the loaded percpu data.init region.
The following adjustments have been made to accomodate the address
change.
* code to locate percpu gdt_page in head_64.S is updated to add the
load address to the gdt_page offset.
* __per_cpu_load is used in places where access to the init data area
is necessary.
* pda->data_offset is initialized soon after C code is entered as zero
value doesn't work anymore.
This patch is mostly taken from Mike Travis' "x86_64: Base percpu
variables at zero" patch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix debug/crash printout
Since errorcode is popped out, RIP is on the top of the stack.
Use real RIP value instead of wrong CS.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This reverts commit 033786969d1d1b5af12a32a19d3a760314d05329.
Suresh Siddha reported that this broke booting on his 2GB testbox.
Reported-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add the Xen entrypoint and ELF notes to head_64.S. Adapts xen-head.S
to compile either 32-bit or 64-bit.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Early fixmap will allocate its own L1 pagetable page for fixmap
mappings, so there's no need to preallocate one.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Consistently set _PAGE_GLOBAL in _PAGE_KERNEL flags. This makes 32-
and 64-bit code consistent, and removes some special cases where
__PAGE_KERNEL* did not have _PAGE_GLOBAL set, causing confusion as a
result of the inconsistencies.
This patch only affects x86-64, which generally always supports PGD.
The x86-32 patch is next.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Ingo Molnar wrote:
> -tip auto-testing found pagetable corruption (CPA self-test failure):
>
> [ 32.956015] CPA self-test:
> [ 32.958822] 4k 2048 large 508 gb 0 x 2556[ffff880000000000-ffff88003fe00000] miss 0
> [ 32.964000] CPA ffff88001d54e000: bad pte 1d4000e3
> [ 32.968000] CPA ffff88001d54e000: unexpected level 2
> [ 32.972000] CPA ffff880022c5d000: bad pte 22c000e3
> [ 32.976000] CPA ffff880022c5d000: unexpected level 2
> [ 32.980000] CPA ffff8800200ce000: bad pte 200000e3
> [ 32.984000] CPA ffff8800200ce000: unexpected level 2
> [ 32.988000] CPA ffff8800210f0000: bad pte 210000e3
>
> config and full log can be found at:
>
> http://redhat.com/~mingo/misc/config-Mon_Jun_30_11_11_51_CEST_2008.bad
> http://redhat.com/~mingo/misc/log-Mon_Jun_30_11_11_51_CEST_2008.bad
Phew. OK, I've worked this out. Short version is that's it's a false
alarm, and there was no real failure here. Long version:
* I changed the code to create the physical mapping pagetables to
reuse any existing mapping rather than replace it. Specifically,
reusing an pud pointed to by the pgd caused this symptom to appear.
* The specific PUD being reused is the one created statically in
head_64.S, which creates an initial 1GB mapping.
* That mapping doesn't have _PAGE_GLOBAL set on it, due to the
inconsistency between __PAGE_* and PAGE_*.
* The CPA test attempts to clear _PAGE_GLOBAL, and then checks to
see that the resulting range is 1) shattered into 4k pages, and 2)
has no _PAGE_GLOBAL.
* However, since it didn't have _PAGE_GLOBAL on that range to start
with, change_page_attr_clear() had nothing to do, and didn't
bother shattering the range,
* resulting in the reported messages
The simple fix is to set _PAGE_GLOBAL in level2_ident_pgt.
An additional fix to make CPA testing more robust by using some other
pagetable bit (one of the unused available-to-software ones). This
would solve spurious CPA test warnings under Xen which uses _PAGE_GLOBAL
for its own purposes (ie, not under guest control).
Also, we should revisit the use of _PAGE_GLOBAL in asm-x86/pgtable.h,
and use it consistently, and drop MAKE_GLOBAL. The first time I
proposed it it caused breakages in the very early CPA code; with luck
that's all fixed now.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Mark McLoughlin <markmc@redhat.com>
Cc: xen-devel <xen-devel@lists.xensource.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Set __PAGE_OFFSET to the most negative possible address +
16*PGDIR_SIZE. The gap is to allow a space for a hypervisor to fit.
The gap is more or less arbitrary, but it's what Xen needs.
When booting native, kernel/head_64.S has a set of compile-time
generated pagetables used at boot time. This patch removes their
absolutely hard-coded layout, and makes it parameterised on
__PAGE_OFFSET (and __START_KERNEL_map).
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: xen-devel <xen-devel@lists.xensource.com>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
i386 and x86_64 used two different schemes for maintaining the gdt.
With this patch, x86_64 initial gdt table is defined in a .c file,
same way as i386 is now. Also, we call it "gdt_page", and the descriptor,
"early_gdt_descr". This way we achieve common naming, which can allow for
more code integration.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
call x86_64's init_rsp stack_start, just as i386 does.
Put a zeroed stack segment for consistency. With this,
we can eliminate one ugly ifdef in smpboot.c.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Since the trampoline code is now used for ACPI resume from suspend to RAM,
the trampoline page tables have to be fixed up during boot not only on SMP
systems, but also on UP systems that use the trampoline.
Reference: http://bugzilla.kernel.org/show_bug.cgi?id=10923
Reported-by: Dionisus Torimens <djtm@gmx.net>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: pm list <linux-pm@lists.linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
We should better use already defined flags from processor-flags.h instead
of defining own ones
[>>> object code check >>>]
original
md5sum: 9cfa6dbf045a046bb5dfb85f8bcfe8c4 arch/x86/kernel/head_64.o
text data bss dec hex filename
37361 4432 8192 49985 c341 arch/x86/kernel/head_64.o
patched
md5sum: 9cfa6dbf045a046bb5dfb85f8bcfe8c4 arch/x86/kernel/head_64.o
text data bss dec hex filename
37361 4432 8192 49985 c341 arch/x86/kernel/head_64.o
[<<< object code check <<<]
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Move wakeup code to .c, so that video mode setting code can be shared
between boot and wakeup. Remove nasty assembly code in 64-bit case by
re-using trampoline code. Stack setup was fixed to clear high 16bits
of %esp, maybe that fixes some machines.
.c code sharing and morse code was done H. Peter Anvin, Sam Ravnborg
reviewed kbuild related stuff, and it seems okay to him. Rafael did
some cleanups.
[rjw:
* Made the patch stop breaking compilation on x86-32
* Added arch/x86/kernel/acpi/sleep.h
* Got rid of compiler warnings in arch/x86/kernel/acpi/sleep.c
* Fixed 32-bit compilation on x86-64 systems
* Added include/asm-x86/trampoline.h and fixed the non-SMP
compilation on 64-bit x86
* Removed arch/x86/kernel/acpi/sleep_32.c which was not used
* Fixed some breakage caused by the integration of smpboot.c done
under us in the meantime]
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Currently they are in .text.head because the rest of head_64.S.
.text.head is not removed as init data, but the early exception handlers
should be because they are not needed after early boot of the BP.
So move them over.
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: mingo@elte.hu
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The early exception handlers are currently set up using a macro
recursion. There is only one user left. Replace the macro with a
standard loop in place.
Noop patch, just a cleanup.
[ tglx@linutronix.de: simplified ]
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: mingo@elte.hu
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
All of early setup runs with interrupts disabled, so there is no
need to set up early exception handlers for vectors >= 32
This saves some minor text size.
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: mingo@elte.hu
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
people sometimes do crazy stuff like building really large static
arrays into their kernels or building allyesconfig kernels. Give
more space to the kernel and push modules up a bit: kernel has
512 MB and modules have 1.5 GB.
Should be enough for a few years ;-)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The KERNEL_TEXT_SIZE constant was mis-named, as we not only map the kernel
text but data, bss and init sections as well.
That name led me on the wrong path with the KERNEL_TEXT_SIZE regression,
because i knew how big of _text_ my images have and i knew about the 40 MB
"text" limit so i wrongly thought to be on the safe side of the 40 MB limit
with my 29 MB of text, while the total image size was slightly above 40 MB.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
recently the 64-bit allyesconfig bzImage kernel started spontaneously
rebooting during early bootup.
after a few fun hours spent with early init debugging, it turns out
that we've got this rather annoying limit on the size of the kernel
image:
#define KERNEL_TEXT_SIZE (40*1024*1024)
which limit my vmlinux just happened to pass:
text data bss dec hex filename
29703744 4222751 8646224 42572719 2899baf vmlinux
40 MB is 42572719 bytes, so my vmlinux was just 1.5% above this limit :-/
So it happily crashed right in head_64.S, which - as we all know - is
the most debuggable code in the whole architecture ;-)
So increase the limit to allow an up to 128MB kernel image to be mapped.
(should anyone be that crazy or lazy)
We have a full 4K of pagetable (level2_kernel_pgt) allocated for these
mappings already, so there's no RAM overhead and the limit was rather
pointless and arbitrary.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
initial_code are initially used to hold a function pointer
from __init and later from __cpuinit. This confuses modpost
and changing initial_code to REFDATA silence the warning.
(But now we do not discard the variable anymore).
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The early boot code maps KERNEL_TEXT_SIZE (currently 40MB) starting
from __START_KERNEL_map. The kernel itself only needs _text to _end
mapped in the high alias. On relocatible kernels the ASM setup code
adjusts the compile time created high mappings to the relocation. This
creates invalid pmd entries for negative offsets:
0xffffffff80000000 -> pmd entry: ffffffffff2001e3
It points outside of the physical address space and is marked present.
This starts at the virtual address __START_KERNEL_map and goes up to
the point where the first valid physical address (0x0) is mapped.
Zap the mappings before _text and after _end right away in early
boot. This removes also the invalid entries.
Furthermore it simplifies the range check for high aliases.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
It's not too pretty, but I found this made the "PANIC: early exception"
messages become much more reliably useful: 1. print the vector number,
2. print the %cs value, 3. handle error-code-pushing vs non-pushing vectors.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
under paravirt, read cr2 cannot be issued directly anymore.
So wrap it in a macro, defined to the operation itself in case
paravirt is off, but to something else if we have paravirt
in the game
Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
