Commit Graph

1027 Commits

Author SHA1 Message Date
Andi Kleen
2049336f60 [PATCH] Don't synchronize time reading on single core AMD systems
We do some additional CPU synchronization in gettimeofday et.al. to make
sure the time stamps are always monotonic over multiple CPUs. But on
single core systems that is not needed. So don't do it.

Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:41 +02:00
Andi Kleen
9ddab42d1e [PATCH] Remove outdated comment in x86-64 mmconfig code
Cc: gregkh@suse.de
Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:41 +02:00
Andi Kleen
27fbe5b28a [PATCH] Use string instructions for Core2 copy/clear
It is faster than using a unrolled loop for the use cases the kernel
cares about (cached, sizes typically < 4K)

Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:41 +02:00
Matthew Garrett
35d534a3ff [PATCH] x86: - restore i8259A eoi status on resume
Got it. i8259A_resume calls init_8259A(0) unconditionally, even if
auto_eoi has been set. Keep track of the current status and restore that
on resume. This fixes it for AMD64 and i386.

Signed-off-by: Matthew Garrett <mjg59@srcf.ucam.org>
Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:41 +02:00
Aaron Durbin
4c6e052adf [PATCH] MMCONFIG and new Intel motherboards
On Sat, Sep 09, 2006 at 04:14:29PM +0200, Andi Kleen wrote:
> [patch] Looks reasonable, but probably not for 2.6.18 because this stuff
> is already too fragile and it is probably too risky to do any big changes now
> since not enough testing time is left. Can you please resubmit
> it with proper description and signed-off-by line? I can queue it for .19 then
>
> -Andi

Patch inserts PCI memory mapped config region(s) into the resource map.  This
will allow for the MMCCONFIG regions to be marked as busy in the iomem
address space as well as the regions(s) showing up in /proc/iomem.

Signed-off-by: Aaron Durbin <adurbin@google.com>
Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:40 +02:00
Aaron Durbin
56dd669a13 [PATCH] Insert GART region into resource map
Patch inserts the GART region into the iomem resource map. The GART will then
be visible within /proc/iomem. It will also allow for other users
utilizing the GART to subreserve the region (agp or IOMMU).

Signed-off-by: Aaron Durbin <adurbin@google.com>
Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:40 +02:00
Andi Kleen
9abd79280b [PATCH] i386/x86-64: Only do MCFG e820 check when type 1 works
Needs earlier patch to split type 1 probing from use.

This patch should fix the x86 macs where type 1 PCI config space access
doesn't work, but MCFG does. They also don't have a usable e820 table
so the e820 sanity check failed.

Instead assume now that if type 1 doesn't work then MCFG must work
and don't do the e820 check.

Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:40 +02:00
Andi Kleen
5e544d618f [PATCH] i386/x86-64: PCI: split probing and initialization of type 1 config space access
First probe if type1/2 accesses work, but then only initialize them at the end.

This is useful for a later patch that needs this information inbetween.

Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:40 +02:00
Andi Kleen
a15da49deb [PATCH] Fix idle notifiers
Previously exit_idle would be called more often than enter_idle

Now instead of using complicated tests just keep track of it
using the per CPU variable as a flip flop.  I moved the idle state into the
PDA to make the access more efficient.

Original bug report and an initial patch from Stephane Eranian,
but redone by AK.

Cc: Stephane Eranian <eranian@hpl.hp.com>

Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:40 +02:00
Eric W. Biederman
1c9c0a6ca3 [PATCH] Remove experimental mark of kexec
kexec has been marked experimental for a year now and all
of the serious problems have been worked through.  So it
is time (if not past time) to remove the experimental mark.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:40 +02:00
Andi Kleen
b38337a624 [PATCH] Mark per cpu data initialization __initdata again
Before 2.6.16 this was changed to work around code that accessed
CPUs not in the possible map. But that code should be all fixed now,
so mark it __initdata again.
Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:40 +02:00
Andi Kleen
26c13f2b5b [PATCH] Check return values of __copy_to_user in uname emulation
Quietens some new warnings
Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:40 +02:00
Andi Kleen
95912008ba [PATCH] Add __must_check to copy_*_user
Following i386.

And also fix the two occurrences that caused warnings in arch/x86_64/*

Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:39 +02:00
Andi Kleen
3022d734a5 [PATCH] Fix zeroing on exception in copy_*_user
- Don't zero for __copy_from_user_inatomic following i386.
This will prevent spurious zeros for parallel file system writers when
one does a exception
- The string instruction version didn't zero the output on
exception. Oops.

Also I cleaned up the code a bit while I was at it and added a minor
optimization to the string instruction path.

Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:39 +02:00
adurbin@google.com
54dbc0c9eb [PATCH] insert IOAPIC(s) and Local APIC into resource map
This patch places the IOAPIC(s) and the Local APIC specified by ACPI
tables into the resource map. The APICs will then be visible within
/proc/iomem

Signed-off-by: Aaron Durbin <adurbin@google.com>
Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:39 +02:00
Andi Kleen
7b0bda74f7 [PATCH] Fix a PDA warning uncovered by the new type checking
Fix
linux/arch/x86_64/kernel/process.c: In function __switch_to:
linux/arch/x86_64/kernel/process.c:626: warning: assignment makes integer from pointer without a cast

Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:39 +02:00
Andi Kleen
96e540492a [PATCH] Fix a irqcount comment in entry.S
Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:39 +02:00
Arjan van de Ven
4f7fd4d7a7 [PATCH] Add the -fstack-protector option to the CFLAGS
Add a feature check that checks that the gcc compiler has stack-protector
support and has the bugfix for PR28281 to make this work in kernel mode.
The easiest solution I could find was to have a shell script in scripts/
to do the detection; if needed we can make this fancier in the future
without making the makefile too complex.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
CC: Andi Kleen <ak@suse.de>
CC: Sam Ravnborg <sam@ravnborg.org>
2006-09-26 10:52:39 +02:00
Arjan van de Ven
0a42540580 [PATCH] Add the canary field to the PDA area and the task struct
This patch adds the per thread cookie field to the task struct and the PDA.
Also it makes sure that the PDA value gets the new cookie value at context
switch, and that a new task gets a new cookie at task creation time.

Signed-off-by: Arjan van Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andi Kleen <ak@suse.de>
CC: Andi Kleen <ak@suse.de>
2006-09-26 10:52:38 +02:00
Arjan van de Ven
b62a5c740d [PATCH] Add the Kconfig option for the stackprotector feature
This patch adds the config options for -fstack-protector.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andi Kleen <ak@suse.de>
CC: Andi Kleen <ak@suse.de>
2006-09-26 10:52:38 +02:00
Andi Kleen
e8c7391de4 [PATCH] Don't use kernel_text_address in oops context
Because it can take spinlocks.

Suggested by Mathieu Desnoyers

Cc: Mathieu Desnoyers <compudj@krystal.dyndns.org>

Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:38 +02:00
Magnus Damm
4bfaaef01a [PATCH] Avoid overwriting the current pgd (V4, x86_64)
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>
2006-09-26 10:52:38 +02:00
Keith Owens
f574164491 [PATCH] Remove most of the special cases for the debug IST stack
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>
2006-09-26 10:52:38 +02:00
Andi Kleen
53ee11ae0d [PATCH] Optimize PDA accesses slightly
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>
2006-09-26 10:52:38 +02:00
Ian Campbell
f2a9e1dec2 [PATCH] Put .note.* sections into a PT_NOTE segment
This patch updates x86_64 linker script to pack any .note.* sections
into a PT_NOTE segment in the output file.

To do this, we tell ld that we need a PT_NOTE segment.  This requires
us to start explicitly mapping sections to segments, so we also need
to explicitly create PT_LOAD segments for text and data, and map the
sections to them appropriately.  Fortunately, each section will
default to its previous section's segment, so it doesn't take many
changes to vmlinux.lds.S.

The corresponding change is already made for i386 in -mm and I'd like
this patch to join it. The section to segment mappings do change as do
the segment flags so some time in -mm would be good for that reason as
well, just in case.

In particular .data and .bss move from the text segment to the data
segment and .data.cacheline_aligned .data.read_mostly are put in the
data segment instead of a separate one.

I think that it would be possible to exactly match the existing section
to segment mapping and flags but it would be a more intrusive change and
I'm not sure there is a reason for the existing layout other than it is
what you get by default if you don't explicitly specify something else.
If there is a reason for the existing layout then I will of course make
the more intrusive change. If there is no reason we could probably drop
the executable or writable flags from some segments but I don't know how
much attention is paid to them anyway so it might not be worth the
effort.

The vsyscall related sections need to go in a different segment to the
normal data segment and so I invented a "user" segment to contain them.
I believe this should appear to be another data segment as far as the
kernel is concerned so the flags are setup accordingly.

The notes will be used in the Xen paravirt_ops backend to provide
additional information to the domain builder. I am in the process of
converting the xen-unstable kernels and tools over to this scheme at the
moment to support this in the future.

It has been suggested to me that the notes segment should have flags 0
(i.e. not readable) since it is only used by the loader and is not used
at runtime. For now I went with a readable segment since that is what
the i386 patch uses.

AK: dropped NOTES addition right now because the needed infrastructure
for that is not merged yet

Signed-off-by: Ian Campbell <ian.campbell@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:38 +02:00
Eric W. Biederman
26374c7b7d [PATCH] Reload CS when startup_64 is used.
In long mode the %cs is largely a relic.  However there are a few cases
like iret where it matters that we have a valid value.  Without this
patch it is possible to enter the kernel in startup_64 without setting
%cs to a valid value.  With this patch we don't care what %cs value
we enter the kernel with, so long as the cs shadow register indicates
it is a privileged code segment.

Thanks to Magnus Damm for finding this problem and posting the
first workable patch.  I have moved the jump to set %cs down a
few instructions so we don't need to take an extra jump.  Which
keeps the code simpler.

Signed-of-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:38 +02:00
Andi Kleen
8380aabb99 [PATCH] Remove non e820 fallbacks in high level code
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>
2006-09-26 10:52:37 +02:00
Paolo 'Blaisorblade' Giarrusso
b3698c03eb [PATCH] Fix boot code head.S warning
When compiling a 64-bit kernel on an Ubuntu 6.06 32bit system (whose GCC is also
a cross-compiler for x86_64) I've seen that head.o is compiled as a 64-bit file
(while it should not) and ld complaining about this during linking:
[AK: it happens on all systems with new binutils]

ld: warning: i386:x86-64 architecture of input file
`arch/x86_64/boot/compressed/head.o' is incompatible with i386 output

I've verified that removing -m64 from compilation flags to turn
"-m64 -traditional -m32" into "-traditional -m32" fixes the issue.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:37 +02:00
Andi Kleen
7a0a2dff1c [PATCH] Add a missing check for irq flags tracing in NMI
NMIs are not supposed to track the irq flags, but TRACE_IRQS_IRETQ
did it anyways. Add a check.

Cc: mingo@elte.hu

Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:37 +02:00
Andi Kleen
aecc63615e [PATCH] Fix coding style and output of the mptable parser
Give the printks a consistent prefix.
Add some missing white space.

Cc: len.brown@intel.com

Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:37 +02:00
Andi Kleen
e4251e130d [PATCH] Remove some cruft in apic id checking during processor setup
- 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>
2006-09-26 10:52:37 +02:00
Andi Kleen
f2c2cca3ac [PATCH] Remove APIC version/cpu capability mpparse checking/printing
ACPI went to great trouble to get the APIC version and CPU capabilities
of different CPUs before passing them to the mpparser. But all
that data was used was to print it out.  Actually it even faked some data
based on the boot cpu, not on the actual CPU being booted.

Remove all this code because it's not needed.

Cc: len.brown@intel.com

Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:37 +02:00
Andi Kleen
5e6b0bfe5b [PATCH] Use proper accessors to change PSE bits in change_page_attr()
Use normal pte accessors in change_page_attr() to access the PSE
bits.

Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:37 +02:00
Andi Kleen
df992848f5 [PATCH] Fix pte_exec/mkexec and use it in change_page_attr()
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>
2006-09-26 10:52:37 +02:00
Andi Kleen
d3cf7f0615 [PATCH] Remove bogus warning from early_ioremap
It is correct for its only caller right now, but not for possible
future others.

Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:37 +02:00
Andi Kleen
151f8cc116 [PATCH] Remove safe_smp_processor_id()
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>
2006-09-26 10:52:37 +02:00
Rafael J. Wysocki
34464a5b89 [PATCH] Detect clock skew during suspend
Detect the situations in which the time after a resume from disk would
be earlier than the time before the suspend and prevent them from
happening on x86_64.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:37 +02:00
Andrew Morton
1164c9994f [PATCH] make numa_emulation() __init
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:37 +02:00
Andi Kleen
dbf9272e86 [PATCH] Don't force reserve the 640k-1MB range
From i386 x86-64 inherited code to force reserve the 640k-1MB area.
That was needed on some old systems.

But we generally trust the e820 map to be correct on 64bit systems
and mark all areas that are not memory correctly.

This patch will allow to use the real memory in there.

Or rather the only way to find out if it's still needed is to
try. So far I'm optimistic.

Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:36 +02:00
Magnus Damm
ed77504b20 [PATCH] mark init_amd() as __cpuinit
The init_amd() function is only called from identify_cpu() which is already
marked as __cpuinit. So let's mark it as __cpuinit.

Signed-off-by: Magnus Damm <magnus@valinux.co.jp>
Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:36 +02:00
Keith Mannthey
6ad9165811 [PATCH] x86_64 kernel mapping fix
Fix for the x86_64 kernel mapping code.  Without this patch the update path
only inits one pmd_page worth of memory and tramples any entries on it.  now
the calling convention to phys_pmd_init and phys_init is to always pass a
[pmd/pud] page not an offset within a page.

Signed-off-by: Keith Mannthey<kmannth@us.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
2006-09-26 10:52:36 +02:00
Andrew Morton
abf0f10948 [PATCH] wire up oops_enter()/oops_exit()
Implement pause_on_oops() on x86_64.

AK: I redid the patch to do the oops_enter/exit in the existing
oops_begin()/end(). This makes it much shorter.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:36 +02:00
Arjan van de Ven
e07e23e1fd [PATCH] non lazy "sleazy" fpu implementation
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>
2006-09-26 10:52:36 +02:00
Brice Goglin
40bee2ee73 [PATCH] fix bus numbering format in mmconfig warning
Make an mmconfig warning print the bus id with a regular format.

Signed-off-by: Brice Goglin <brice@myri.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
2006-09-26 10:52:35 +02:00
Eric W. Biederman
ba4d40bb5c [PATCH] Auto size the per cpu area.
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>
2006-09-26 10:52:35 +02:00
Andi Kleen
273819a2d9 [PATCH] make fault notifier unconditional and export it
It's needed for external debuggers and overhead is very small.

Also make the actual notifier chain they use static

Cc: jbeulich@novell.com

Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:35 +02:00
Andi Kleen
2717941c6a [PATCH] Make boot_param_data pure BSS
Since it's all zero.

Actually I think gcc 4+ will do that automatically, but earlier compilers won't
Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:35 +02:00
Andi Kleen
1edf777803 [PATCH] i386/x86-64: Improve Kconfig description of CRASH_DUMP
Improve Kconfig description of CONFIG_CRASH_DUMP. Previously
it was too brief to be useful.

Cc: vgoyal@in.ibm.com
Cc: ebiederm@xmission.com

Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:35 +02:00
Dimitri Sivanich
cbf9b4bb76 [PATCH] X86_64 monotonic_clock goes backwards
I've noticed some erratic behavior while testing the X86_64 version
of monotonic_clock().

While spinning in a loop reading monotonic clock values (pinned to a
single cpu) I noticed that the difference between subsequent values
occasionally went negative (time going backwards).

I found that in the following code:
                this_offset = get_cycles_sync();
                /* FIXME: 1000 or 1000000? */
-->             offset = (this_offset - last_offset)*1000 / cpu_khz;
        }
        return base + offset;

the offset sometimes turns out to be 0, even though
this_offset > last_offset.

+Added fix From: Toyo Abe <toyoa@mvista.com>

The x86_64-mm-monotonic-clock.patch in 2.6.18-rc4-mm2 made a change to
the updating of monotonic_base. It now uses cycles_2_ns().

I suggest that a set_cyc2ns_scale() should be done prior to the setup_irq().
Because cycles_2_ns() can be called from the timer ISR right after the irq0
is enabled.

Signed-off-by: Toyo Abe <toyoa@mvista.com>
Signed-off-by: Dimitri Sivanich <sivanich@sgi.com>
Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26 10:52:34 +02:00
Prasanna S.P
d28c4393a7 [PATCH] x86: error_code is not safe for kprobes
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>
2006-09-26 10:52:34 +02:00