kexec: Avoid overwriting the current pgd (V4, x86_64)
This patch upgrades the x86_64-specific kexec code to avoid overwriting the
current pgd. Overwriting the current pgd is bad when CONFIG_CRASH_DUMP is used
to start a secondary kernel that dumps the memory of the previous kernel.
The code introduces a new set of page tables. These tables are used to provide
an executable identity mapping without overwriting the current pgd.
Signed-off-by: Magnus Damm <magnus@valinux.co.jp>
Signed-off-by: Andi Kleen <ak@suse.de>
Remove most of the special cases for the debug IST stack. This is a
follow on clean up patch, it requires the bug fix patch that adds
orig_ist.
Signed-off-by: Keith Owens <kaos@ocs.com.au>
Signed-off-by: Andi Kleen <ak@suse.de>
The EDD code would scan the command line as a fixed array, without
taking account of either whitespace, null-termination, the old
command-line protocol, late overrides early, or the fact that the
command line may not be reachable from INITSEG.
This should fix those problems, and enable us to use a longer command
line.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Based on a idea by Jeremy Fitzhardinge:
Replace the volatiles and memory clobbers in the PDA access with
telling gcc about access to a proxy PDA structure that doesn't
actually exist. But the dummy accesses give a defined ordering for
read/write accesses.
Also add some memory barriers to the early GS initialization to
make sure no PDA access is moved before it.
Advantage is some .text savings (probably most from better
code for accessing "current"):
text data bss dec hex filename
4845647 1223688 615864 6685199 66020f vmlinux
4837780 1223688 615864 6677332 65e354 vmlinux-pda
1.2% smaller code
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Based on patch from David Rientjes <rientjes@google.com>, but
changed by AK.
Optimizes the 64-bit hamming weight for x86_64 processors assuming they
have fast multiplication. Uses five fewer bitops than the generic
hweight64. Benchmark on one EMT64 showed ~25% speedup with 2^24
consecutive calls.
Define a new ARCH_HAS_FAST_MULTIPLIER that can be set by other
architectures that can also multiply fast.
Signed-off-by: Andi Kleen <ak@suse.de>
Drop support for non e820 BIOS calls to get the memory map.
The boot assembler code still has some support, but not the C code now.
Signed-off-by: Andi Kleen <ak@suse.de>
- Remove a define that was used only once
- Remove the too large APIC ID check because we always support
the full 8bit range of APICs.
- Restructure code a bit to be simpler.
Cc: len.brown@intel.com
Signed-off-by: Andi Kleen <ak@suse.de>
Fix the pte_exec/mkexec page table accessor functions to really
use the NX bit. Previously they only checked the USER bit, but
weren't actually used for anything.
Then use them in change_page_attr() to manipulate the NX bit
properly.
Signed-off-by: Andi Kleen <ak@suse.de>
And replace all users with ordinary smp_processor_id. The function
was originally added to get some basic oops information out even
if the GS register was corrupted. However that didn't
work for some anymore because printk is needed to print the oops
and it uses smp_processor_id() already. Also GS register corruptions
are not particularly common anymore.
This also helps the Xen port which would otherwise need to
do this in a special way because it can't access the local APIC.
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andi Kleen <ak@suse.de>
In i386's entry.S, FIX_STACK() needs annotation because it
replaces the stack pointer. And the rest of nmi() needs
annotation in order to compile with these new annotations.
Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Apparently IA64 needs it, but i386/x86-64 don't anymore
since gcc 2.95 support was dropped. Nobody else on linux-arch
requested keeping it generically
Cc: tony.luck@intel.com
Cc: kaos@sgi.com
Signed-off-by: Andi Kleen <ak@suse.de>
Right now the kernel on x86-64 has a 100% lazy fpu behavior: after *every*
context switch a trap is taken for the first FPU use to restore the FPU
context lazily. This is of course great for applications that have very
sporadic or no FPU use (since then you avoid doing the expensive
save/restore all the time). However for very frequent FPU users... you
take an extra trap every context switch.
The patch below adds a simple heuristic to this code: After 5 consecutive
context switches of FPU use, the lazy behavior is disabled and the context
gets restored every context switch. If the app indeed uses the FPU, the
trap is avoided. (the chance of the 6th time slice using FPU after the
previous 5 having done so are quite high obviously).
After 256 switches, this is reset and lazy behavior is returned (until
there are 5 consecutive ones again). The reason for this is to give apps
that do longer bursts of FPU use still the lazy behavior back after some
time.
[akpm@osdl.org: place new task_struct field next to jit_keyring to save space]
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
This patch enables ACPI based physical CPU hotplug support for x86_64.
Implements acpi_map_lsapic() and acpi_unmap_lsapic() to support physical cpu
hotplug.
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@muc.de>
Cc: "Brown, Len" <len.brown@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Now for a completely different but trivial approach.
I just boot tested it with 255 CPUS and everything worked.
Currently everything (except module data) we place in
the per cpu area we know about at compile time. So
instead of allocating a fixed size for the per_cpu area
allocate the number of bytes we need plus a fixed constant
for to be used for modules.
It isn't perfect but it is much less of a pain to
work with than what we are doing now.
AK: fixed warning
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andi Kleen <ak@suse.de>
The implementation comes from Zach's [RFC, PATCH 10/24] i386 Vmi
descriptor changes:
Descriptor and trap table cleanups. Add cleanly written accessors for
IDT and GDT gates so the subarch may override them. Note that this
allows the hypervisor to transparently tweak the DPL of the descriptors
as well as the RPL of segments in those descriptors, with no unnecessary
kernel code modification. It also allows the hypervisor implementation
of the VMI to tweak the gates, allowing for custom exception frames or
extra layers of indirection above the guest fault / IRQ handlers.
Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andi Kleen <ak@suse.de>
This patch moves the entry.S:error_entry to .kprobes.text section,
since code marked unsafe for kprobes jumps directly to entry.S::error_entry,
that must be marked unsafe as well.
This patch also moves all the ".previous.text" asm directives to ".previous"
for kprobes section.
AK: Following a similar i386 patch from Chuck Ebbert
AK: Also merged Jeremy's fix in.
+From: Jeremy Fitzhardinge <jeremy@goop.org>
KPROBE_ENTRY does a .section .kprobes.text, and expects its users to
do a .previous at the end of the function.
Unfortunately, if any code within the function switches sections, for
example .fixup, then the .previous ends up putting all subsequent code
into .fixup. Worse, any subsequent .fixup code gets intermingled with
the code its supposed to be fixing (which is also in .fixup). It's
surprising this didn't cause more havok.
The fix is to use .pushsection/.popsection, so this stuff nests
properly. A further cleanup would be to get rid of all
.section/.previous pairs, since they're inherently fragile.
+From: Chuck Ebbert <76306.1226@compuserve.com>
Because code marked unsafe for kprobes jumps directly to
entry.S::error_code, that must be marked unsafe as well.
The easiest way to do that is to move the page fault entry
point to just before error_code and let it inherit the same
section.
Also moved all the ".previous" asm directives for kprobes
sections to column 1 and removed ".text" from them.
Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Following x86-64 patches. Reuses code from them in fact.
Convert the standard backtracer to do all output using
callbacks. Use the x86-64 stack tracer implementation
that uses these callbacks to implement the stacktrace interface.
This allows to use the new dwarf2 unwinder for stacktrace
and get better backtraces.
Cc: mingo@elte.hu
Signed-off-by: Andi Kleen <ak@suse.de>
This unifies the standard backtracer and the new stacktrace
in memory backtracer. The standard one is converted to use callbacks
and then reimplement stacktrace using new callbacks.
The main advantage is that stacktrace can now use the new dwarf2 unwinder
and avoid false positives in many cases.
I kept it simple to make sure the standard backtracer stays reliable.
Cc: mingo@elte.hu
Signed-off-by: Andi Kleen <ak@suse.de>
Lockdep can call the dwarf2 unwinder early, and the dwarf2 code
uses safe_smp_processor_id which tries to access the local APIC page.
But that doesn't work before the APIC code has set up its fixmap.
Check for this case and always return boot cpu then.
Cc: jbeulich@novell.com
Cc: mingo@elte.hu
Signed-off-by: Andi Kleen <ak@suse.de>
- Remove unused all_contexts parameter
No caller used it
- Move skip argument into the structure (needed for
followon patches)
Cc: mingo@elte.hu
Signed-off-by: Andi Kleen <ak@suse.de>
Instead of hackish manual parsing
Requires earlier i386 patchkit, but also fixes i386 early_printk again.
I removed some obsolete really early parameters which didn't do anything useful.
Also made a few parameters that needed it early (mostly oops printing setup)
Also removed one panic check that wasn't visible without
early console anyways (the early console is now initialized after that
panic)
This cleans up a lot of code.
Signed-off-by: Andi Kleen <ak@suse.de>
This patch replaces the open-coded early commandline parsing
throughout the i386 boot code with the generic mechanism (already used
by ppc, powerpc, ia64 and s390). The code was inconsistent with
whether it deletes the option from the cmdline or not, meaning some of
these will get passed through the environment into init.
This transformation is mainly mechanical, but there are some notable
parts:
1) Grammar: s/linux never set's it up/linux never sets it up/
2) Remove hacked-in earlyprintk= option scanning. When someone
actually implements CONFIG_EARLY_PRINTK, then they can use
early_param().
[AK: actually it is implemented, but I'm adding the early_param it in the next
x86-64 patch]
3) Move declaration of generic_apic_probe() from setup.c into asm/apic.h
4) Various parameters now moved into their appropriate files (thanks Andi).
5) All parse functions which examine arg need to check for NULL,
except one where it has subtle humor value.
AK: readded acpi_sci handling which was completely dropped
AK: moved some more variables into acpi/boot.c
Cc: len.brown@intel.com
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andi Kleen <ak@suse.de>
Lock sections don't work the new dwarf2 unwinder
This generates slightly smaller code. It adds one more taken
jump to the fast path.
Cc: jbeulich@novell.com
Signed-off-by: Andi Kleen <ak@suse.de>
Lock sections don't work the new dwarf2 unwinder
This generates slightly smaller code. It adds one more taken
jump to the fast path.
Also move the trampolines into semaphore.S and add proper CFI
annotations.
Cc: jbeulich@novell.com
Signed-off-by: Andi Kleen <ak@suse.de>
Lock sections don't work the new dwarf2 unwinder
This generates slightly smaller code. It adds one more taken
jump to the fast path.
Cc: jbeulich@novell.com
Signed-off-by: Andi Kleen <ak@suse.de>
Move the tce_table_kva array, disabled bitmap and bus_to_phb array
into a new per bus 'struct calgary_bus_info'. Also slightly reorganize
build_tce_table and tce_table_setparms to avoid exporting bus_info to
tce.c.
Signed-off-by: Muli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: Jon Mason <jdmason@us.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Rearrange struct members loosely based on size for improved alignment
and to save a few bytes.
Signed-off-by: Muli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: Jon Mason <jdmason@us.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
The genapic field and the accessor macro weren't used anywhere.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
... instead of using a CONFIG option. The config option still controls
if the resulting executable actually has unwind information.
This is useful to prevent compilation errors when users select
CONFIG_STACK_UNWIND on old binutils and also allows to use
CFI in the future for non kernel debugging applications.
Cc: jbeulich@novell.com
Cc: sam@ravnborg.org
Signed-off-by: Andi Kleen <ak@suse.de>
They did not really belong into io_apic.c. Move them into a new file
and clean it up a bit.
Also remove outdated ATI quirk that was obsolete,
Signed-off-by: Andi Kleen <ak@suse.de>
PIC mode is an outdated way to drive the APICs that was used on
some early MP boards. It is not supported in the ACPI model.
It is unlikely to be ever configured by any x86-64 system
Remove it thus.
Signed-off-by: Andi Kleen <ak@suse.de>
- Convert CR* accesses to dedicated inline functions and rewrite
the rest as C inlines
- Don't do a double flush for global flushes (pointed out by Zach Amsden)
This was a bug workaround for old CPUs that don't do 64bit and is obsolete.
- Add a proper memory clobber to invlpg
- Remove an unused extern
Signed-off-by: Andi Kleen <ak@suse.de>
IO-APIC or local APIC can only be disabled at runtime anyways and
Kconfig has forced these options on for a long time now.
The Kconfigs are kept only now for the benefit of the shared acpi
boot.c code.
Signed-off-by: Andi Kleen <ak@suse.de>
- Move them to a pure assembly file. Previously they were in
a C file that only consisted of inline assembly. Doing it in pure
assembler is much nicer.
- Add a frame.i include with FRAME/ENDFRAME macros to easily
add frame pointers to assembly functions
- Add dwarf2 annotation to them so that the new dwarf2 unwinder
doesn't get stuck on them
- Random cleanups
Includes feedback from Jan Beulich and a UML build fix from Andrew
Morton.
Cc: jbeulich@novell.com
Cc: jdike@addtoit.com
Signed-off-by: Andi Kleen <ak@suse.de>
LOCK_PREFIX is replaced by nops on UP systems, so it has to be a special
macro. Previously this was only possible from C. Allow it for pure
assembly files too. Similar to earlier x86-64 patch.
Signed-off-by: Andi Kleen <ak@suse.de>
Previously it didn't align. Use the same one as the C compiler
in blended mode, which is good for K8 and Core2 and doesn't hurt
on P4.
Signed-off-by: Andi Kleen <ak@suse.de>
rwlocks are now out of line, so it near never triggers. Also it was
incompatible with the new dwarf2 unwinder because it had unannotiatable
push/pops.
Signed-off-by: Andi Kleen <ak@suse.de>
- Move the slow path fallbacks to their own assembly files
This makes them much easier to read and is needed for the next change.
- Add CFI annotations for unwinding (XXX need review)
- Remove constant case which can never happen with out of line spinlocks
- Use patchable LOCK prefixes
- Don't use lock sections anymore for inline code because they can't
be expressed by the unwinder (this adds one taken jump to the lock
fast path)
Cc: jbeulich@novell.com
Signed-off-by: Andi Kleen <ak@suse.de>
