Ingo Molnar [Wed, 30 Jan 2008 12:33:24 +0000 (13:33 +0100)]
x86: fix up alternatives with lockdep enabled
An older binutils bug caused us to not fix up alternatives.
This problem involved mutex.c but we dont do lockdep section tricks
there anymore, so this workaround is moot. Keep the printk nevertheless,
just in case ... We can remove that later on.
Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
travis@sgi.com [Wed, 30 Jan 2008 12:33:21 +0000 (13:33 +0100)]
x86: change bios_cpu_apicid to percpu data variable fixup
Change static bios_cpu_apicid array to a per_cpu data variable.
This includes using a static array used during initialization
similar to the way x86_cpu_to_apicid[] is handled.
There is one early use of bios_cpu_apicid in apic_is_clustered_box().
The other reference in cpu_present_to_apicid() is called after
smp_set_apicids() has setup the percpu version of bios_cpu_apicid.
Signed-off-by: Mike Travis <travis@sgi.com> Reviewed-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
travis@sgi.com [Wed, 30 Jan 2008 12:33:21 +0000 (13:33 +0100)]
x86: change NR_CPUS arrays in numa_64 fixup
Change the following static arrays sized by NR_CPUS to
per_cpu data variables:
char cpu_to_node_map[NR_CPUS];
fixup:
- Split cpu_to_node function into "early" and "late" versions
so that x86_cpu_to_node_map_early_ptr is not EXPORT'ed and
the cpu_to_node inline function is more streamlined.
- This also involves setting up the percpu maps as early as possible.
- Fix X86_32 NUMA build errors that previous version of this
patch caused.
V2->V3:
- add early_cpu_to_node function to keep cpu_to_node efficient
- move and rename smp_set_apicids() to setup_percpu_maps()
- call setup_percpu_maps() as early as possible
Andi Kleen [Wed, 30 Jan 2008 12:33:21 +0000 (13:33 +0100)]
x86: add generic clearcpuid=... option
Add a generic option to clear any cpuid bit. I added it because it was
very easy to add with the new generic cpuid disable bitmap and perhaps
it will be useful in the future.
Andi Kleen [Wed, 30 Jan 2008 12:33:20 +0000 (13:33 +0100)]
x86: don't disable RDTSC in userland for 32bit notsc
Modern 32bit userland doesn't even boot when the TSC is disabled
because ld.so tends to contain RDTSCs. So make notsc only effective for the
kernel, similar to 64bit.
Andi Kleen [Wed, 30 Jan 2008 12:33:20 +0000 (13:33 +0100)]
x86: add framework to disable CPUID bits on the command line
There are already various options to disable specific cpuid bits
on the command line. They all use their own variable. Add a generic
mask to make this easier in the future.
Eduardo Habkost [Wed, 30 Jan 2008 12:33:20 +0000 (13:33 +0100)]
x86: don't set pagetable_setup_{start,done} hooks on 64-bit
paravirt_pagetable_setup_{start,done}() are not used (yet) under x86_64,
and native_pagetable_setup_{start,done}() don't exist on x86_64. So they
don't need to be set.
__pmd, pmd_val and set_pud are used before they are defined (as static)
We move them a little up in the file, so it doesn't happen.
Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This patch adds the __parainstructions section to vmlinux.lds.S.
It's needed for the patching system.
Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This patch adds the constant PARAVIRT needs in asm_offsets_64.c
Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This patch fills in the read and write cr8 fields with their
native version.
Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Since the cr8 manipulation functions ended up staying in the tree,
they can't be defined just when PARAVIRT is off: In this patch,
those functions are defined for the PARAVIRT case too.
[ mingo@elte.hu: fixes ]
Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This patch adds room for read and write_cr8 functions back in
pv_cpu_ops struct
Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
With PARAVIRT, we actually have arch_{dup,exit}_mmap functions,
so we can't include the generic header
Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
x86_64 lacks a native_init_IRQ() function, so we turn the arch's
init_IRQ() function into a native construct
Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
We use a __stringify construction at paravirt_patch_64.c.
It's better practice to include the stringify header directly
Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Yinghai Lu [Wed, 30 Jan 2008 12:33:18 +0000 (13:33 +0100)]
x86: only call early_init_amd one time
Andi's patch
"
x86: move X86_FEATURE_CONSTANT_TSC into early cpu feature detection
Need this in the next patch in time_init and that happens early.
This includes a minor fix on i386 where early_intel_workarounds()
[which is now called early_init_intel] really executes early as
the comments say.
"
calling early_init_amd in early_identify_cpu and identify_cpu two times.
this patch remove the one in identify_cpu
Signed-off-by: Yinghai Lu <yinghai.lu@sun.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Jesse Barnes [Wed, 30 Jan 2008 12:33:18 +0000 (13:33 +0100)]
x86, 32-bit: trim memory not covered by wb mtrrs
On some machines, buggy BIOSes don't properly setup WB MTRRs to cover all
available RAM, meaning the last few megs (or even gigs) of memory will be
marked uncached. Since Linux tends to allocate from high memory addresses
first, this causes the machine to be unusably slow as soon as the kernel
starts really using memory (i.e. right around init time).
This patch works around the problem by scanning the MTRRs at boot and
figuring out whether the current end_pfn value (setup by early e820 code)
goes beyond the highest WB MTRR range, and if so, trimming it to match. A
fairly obnoxious KERN_WARNING is printed too, letting the user know that
not all of their memory is available due to a likely BIOS bug.
Something similar could be done on i386 if needed, but the boot ordering
would be slightly different, since the MTRR code on i386 depends on the
boot_cpu_data structure being setup.
This patch fixes a bug in the last patch that caused the code to run on
non-Intel machines (AMD machines apparently don't need it and it's untested
on other non-Intel machines, so best keep it off).
Further enhancements and fixes from:
Yinghai Lu <Yinghai.Lu@Sun.COM>
Andi Kleen <ak@suse.de>
Signed-off-by: Jesse Barnes <jesse.barnes@intel.com> Tested-by: Justin Piszcz <jpiszcz@lucidpixels.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This makes it easier to pinpoint bugs to specific libraries.
And printing the offset into a mapping also always allows to find the
correct fault point in a library even with randomized mappings. Previously
there was no way to actually find the correct code address inside
the randomized mapping.
Relies on earlier patch to shorten the printk formats.
They are often now longer than 80 characters, but I think that's worth it.
[includes fix from Eric Dumazet to check d_path error value]
Andi Kleen [Wed, 30 Jan 2008 12:33:17 +0000 (13:33 +0100)]
x86: don't disable the APIC if it hasn't been mapped yet
When the kernel panics early for some unrelated reason
there would be eventually an early exception inside panic because
clear_local_APIC tried to disable the not yet mapped APIC.
Check for that explicitely.
Andi Kleen [Wed, 30 Jan 2008 12:33:17 +0000 (13:33 +0100)]
x86: optimize lock prefix switching to run less frequently
On VMs implemented using JITs that cache translated code changing the lock
prefixes is a quite costly operation that forces the JIT to throw away and
retranslate a lot of code.
Previously a SMP kernel would rewrite the locks once for each CPU which
is quite unnecessary. This patch changes the code to never switch at boot in
the normal case (SMP kernel booting with >1 CPU) or only once for SMP kernel
on UP.
This makes a significant difference in boot up performance on AMD SimNow!
Also I expect it to be a little faster on native systems too because a smp
switch does a lot of text_poke()s which each synchronize the pipeline.
v1->v2: Rename max_cpus
v1->v2: Fix off by one in UP check (Thomas Gleixner)
Andi Kleen [Wed, 30 Jan 2008 12:33:17 +0000 (13:33 +0100)]
x86: replace hard coded reservations in 64-bit early boot code with dynamic table
On x86-64 there are several memory allocations before bootmem. To avoid
them stomping on each other they used to be all hard coded in bad_area().
Replace this with an array that is filled as needed.
This cleans up the code considerably and allows to expand its use.
Andi Kleen [Wed, 30 Jan 2008 12:33:16 +0000 (13:33 +0100)]
x86: use the correct cpuid method to detect MWAIT support for C states
Previously there was a AMD specific quirk to handle the case of
AMD Fam10h MWAIT not supporting any C states. But it turns out
that CPUID already has ways to detectly detect that without
using special quirks.
The new code simply checks if MWAIT supports at least C1 and doesn't
use it if it doesn't. No more vendor specific code.
Note this is does not simply clear MWAIT because MWAIT can be still
useful even without C states.
Credit goes to Ben Serebrin for pointing out the (nearly) obvious.
Harvey Harrison [Wed, 30 Jan 2008 12:33:16 +0000 (13:33 +0100)]
x86: clean up ptrace.h
Leave definition of pt_regs in its own section, move all kernel
code to section afterwards, unify prototype definitions, has some
conditional prototypes to make it clear what was only defined in
32 and 64 bit.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Dmitri Vorobiev [Wed, 30 Jan 2008 12:33:16 +0000 (13:33 +0100)]
x86_32: remove the useless NR_syscalls macro
This is against current x86.git.
The size of the system call table for 32-bit x86 kernels is obtained by
compile-time calculation of the sys_call_table array, not from the value,
which the NR_syscalls macro expands to. This trivial patch removes the
fossil macro.
Manually tested by grepping the x86 files for the "NR_syscalls" string.
No relevant use cases found.
Build-tested using allyesconfig, allnoconfig and a couple of randconfig
instances. All builds successfully finished.
Runtime test performed using a stripped-down Debian-ish config. The system
booted successfully.
Signed-off-by: Dmitri Vorobiev <dmitri.vorobiev@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
PSE, PGE, XMM, XMM2, and FXSR are defined as required features, and
will be optimized to a constant at compile time. Remove their redundant
definitions.
Remove duplicate set_pte* operations. PAE still needs to have special
variants of some of these because it can't atomically update a 64-bit
pte, so there's still some duplication.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Andrew Morton [Wed, 30 Jan 2008 12:33:14 +0000 (13:33 +0100)]
arch/x86/mm/numa_64.c: section fix
WARNING: vmlinux.o(__ksymtab+0x670): Section mismatch: reference to .init.data:x86_cpu_to_node_map_init (between '__ksymtab_x86_cpu_to_node_map_init' and '__ksymtab_node_data')
Cc: Matthew Dobson <colpatch@us.ibm.com> Cc: Mike Travis <travis@sgi.com> Cc: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Jan Beulich [Wed, 30 Jan 2008 12:33:14 +0000 (13:33 +0100)]
x86: adjust/fix LDT handling for Xen
Based on patch from Jan Beulich <jbeulich@novell.com>.
Don't rely on kmalloc(PAGE_SIZE) returning PAGE_SIZE aligned memory
(Xen requires GDT *and* LDT to be page-aligned). Using the page
allocator interface also removes the (albeit small) slab allocator
overhead. The same change being done for 64-bits for consistency.
Further, the Xen hypercall interface expects the LDT address to be
virtual, not machine.
[ Adjusted to unified ldt.c - Jeremy ]
Signed-off-by: Jan Beulich <jbeulich@novell.com> Acked-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Alan Cox [Wed, 30 Jan 2008 12:33:14 +0000 (13:33 +0100)]
x86: serverworks: IRQ routing needs no _p
I can find no reason for the _p on the serverworks IRQ routing logic, and
a review of the documentation contains no indication that any such delay
is needed so lets try this
Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Alan Cox [Wed, 30 Jan 2008 12:33:14 +0000 (13:33 +0100)]
x86: isolate PIC/PIT in/out calls
Rather than remove and/or mangle inb_p/outb_p we want to remove the use
of them from inappropriate places. For the PIC/PIT this may eventually
depend on 32/64bitism or similar so start by adding inb/outb_pit and
inb/outb_pic so that we can make them use any scheme we settle on without
disturbing the existing, correct (for ISA), port 0x80 usage. (eg we can
make inb_pit use udelay without messing up inb_p).
Floppy already does this for the fdc. That really only leaves the CMOS as
a core logic item to tackle, and bits of parallel port handling in the
chipset layers.
Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Abhishek Sagar [Wed, 30 Jan 2008 12:33:13 +0000 (13:33 +0100)]
x86: fix singlestep handling in reenter_kprobe
Highlight peculiar cases in singles-step kprobe handling.
In reenter_kprobe(), a breakpoint in KPROBE_HIT_SS case can only occur
when single-stepping a breakpoint on which a probe was installed. Since
such probes are single-stepped inline, identifying these cases is
unambiguous. All other cases leading up to KPROBE_HIT_SS are possible
bugs. Identify and WARN_ON such cases.
Benjamin LaHaise [Wed, 30 Jan 2008 12:33:13 +0000 (13:33 +0100)]
x86: fix synchronize_rcu(): high latency on idle system
an otherwise idle system takes about 3 ticks per network
interface in unregister_netdev() due to multiple calls to synchronize_rcu(),
which adds up to quite a few seconds for tearing down thousands of
interfaces. By flushing pending rcu callbacks in the idle loop, the system
makes progress hundreds of times faster. If this is indeed a sane thing to,
it probably needs to be done for other architectures than x86. And yes, the
network stack shouldn't call synchronize_rcu() quite so much, but fixing that
is a little more involved.
Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
John Reiser [Wed, 30 Jan 2008 12:33:13 +0000 (13:33 +0100)]
x86: add ENDPROC() markers
The ENDPROCs() were not used everywhere. Some code used just END() instead,
while other code used nothing. um/sys-i386/checksum.S didn't #include
<linux/linkage.h> . I also got confused because gcc puts the
.type near the ENTRY, while ENDPROC puts it on the opposite end.
Signed off by: John Reiser <jreiser@BitWagon.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Harvey Harrison [Wed, 30 Jan 2008 12:33:12 +0000 (13:33 +0100)]
x86: remove last user of get_segment_eip
is_prefetch was the last user of get_segment_eip and only on
X86_32. This function returned the faulting instruction's
address and set the upper segment limit.
Instead, use the convert_ip_to_linear helper and rely on
probe_kernel_address to do the segment checks which was
already done everywhere the segment limit was being checked
on X86_32.
Remove get_segment_eip as well.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Harvey Harrison [Wed, 30 Jan 2008 12:33:12 +0000 (13:33 +0100)]
x86: use wrmsrl in kprobes.c, step.c
Where x86_32 passed zero in the high 32 bits, use wrmsrl which
will zero extend for us. This allows ifdefs for 32/64 bit to
be eliminated.
Eliminate ifdef in step.c. Similar cleanup was done when unifying
kprobes_32|64.c and wrmsr() was chosen there over wrmsrl(). This
patch changes these to wrmsrl.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
travis@sgi.com [Wed, 30 Jan 2008 12:33:12 +0000 (13:33 +0100)]
x86: change bios_cpu_apicid to percpu data variable
Change static bios_cpu_apicid array to a per_cpu data variable.
This includes using a static array used during initialization
similar to the way x86_cpu_to_apicid[] is handled.
There is one early use of bios_cpu_apicid in apic_is_clustered_box().
The other reference in cpu_present_to_apicid() is called after
smp_set_apicids() has setup the percpu version of bios_cpu_apicid.
[ mingo@elte.hu: build fix ]
Signed-off-by: Mike Travis <travis@sgi.com> Reviewed-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
travis@sgi.com [Wed, 30 Jan 2008 12:33:10 +0000 (13:33 +0100)]
x86: change size of APICIDs from u8 to u16
Change the size of APICIDs from u8 to u16. This partially
supports the new x2apic mode that will be present on future
processor chips. (Chips actually support 32-bit APICIDs, but that
change is more intrusive. Supporting 16-bit is sufficient for now).
Signed-off-by: Jack Steiner <steiner@sgi.com>
I've included just the partial change from u8 to u16 apicids. The
remaining x2apic changes will be in a separate patch.
In addition, the fake_node_to_pxm_map[] and fake_apicid_to_node[]
tables have been moved from local data to the __initdata section
reducing stack pressure when MAX_NUMNODES and MAX_LOCAL_APIC are
increased in size.
Signed-off-by: Mike Travis <travis@sgi.com> Reviewed-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Chris Wright [Wed, 30 Jan 2008 12:33:10 +0000 (13:33 +0100)]
x86: fix ioport unification on 32-bit
ioport unification was broken for 32-bit; it was missing
the acutal pushf/popf EFLAGS manipulation (set_iopl_mask()).
Also, use of volatile looks like leftover cruft.
Cc: mboton@gmail.com Cc: Kevin Winchester <kjwinchester@gmail.com> Cc: Zach Brown <zach.brown@oracle.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Yinghai Lu [Wed, 30 Jan 2008 12:33:09 +0000 (13:33 +0100)]
x86: disable the GART early, 64-bit
For K8 system: 4G RAM with memory hole remapping enabled, or more than
4G RAM installed.
when try to use kexec second kernel, and the first doesn't include
gart_shutdown. the second kernel could have different aper position than
the first kernel. and second kernel could use that hole as RAM that is
still used by GART set by the first kernel. esp. when try to kexec
2.6.24 with sparse mem enable from previous kernel (from RHEL 5 or SLES
10). the new kernel will use aper by GART (set by first kernel) for
vmemmap. and after new kernel setting one new GART. the position will be
real RAM. the _mapcount set is lost.
Bad page state in process 'swapper'
page:ffffe2000e600020 flags:0x0000000000000000 mapping:0000000000000000 mapcount:1 count:0
Trying to fix it up, but a reboot is needed
Backtrace:
Pid: 0, comm: swapper Not tainted 2.6.24-rc7-smp-gcdf71a10-dirty #13
new kernel said:
Mapping aperture over 65536 KB of RAM @ 3c000000
So could try to disable that GART if possible.
According to Ingo
> hm, i'm wondering, instead of modifying the GART, why dont we simply
> _detect_ whatever GART settings we have inherited, and propagate that
> into our e820 maps? I.e. if there's inconsistency, then punch that out
> from the memory maps and just dont use that memory.
>
> that way it would not matter whether the GART settings came from a [old
> or crashing] Linux kernel that has not called gart_iommu_shutdown(), or
> whether it's a BIOS that has set up an aperture hole inconsistent with
> the memory map it passed. (or the memory map we _think_ i tried to pass
> us)
>
> it would also be more robust to only read and do a memory map quirk
> based on that, than actively trying to change the GART so early in the
> bootup. Later on we have to re-enable the GART _anyway_ and have to
> punch a hole for it.
>
> and as a bonus, we would have shored up our defenses against crappy
> BIOSes as well.
add e820 modification for gart inconsistent setting.
gart_fix_e820=off could be used to disable e820 fix.
Signed-off-by: Yinghai Lu <yinghai.lu@sun.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Arjan van de Ven [Wed, 30 Jan 2008 12:33:08 +0000 (13:33 +0100)]
x86: make printk_address regs->ip always reliable
printk_address()'s second parameter is the reliability indication,
not the ebp. If we're printing regs->ip we're reliable by definition,
so pass a 1 here.
Signed-off-by: Arjan van de Ven Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Arjan van de Ven [Wed, 30 Jan 2008 12:33:08 +0000 (13:33 +0100)]
x86: add the "print code before the trapping instruction" feature to 64 bit
The 32 bit x86 tree has a very useful feature that prints the Code: line
for the code even before the trapping instrution (and the start of the
trapping instruction is then denoted with a <>). Unfortunately, the 64 bit
x86 tree does not yet have this feature, making diagnosing backtraces harder
than needed.
This patch adds this feature in the same was as the 32 bit tree has
(including the same kernel boot parameter), and including a bugfix
to make the code use probe_kernel_address() rarther than a buggy (deadlocking)
__get_user.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Arjan van de Ven [Wed, 30 Jan 2008 12:33:08 +0000 (13:33 +0100)]
x86: add a simple backtrace test module
During the work on the x86 32 and 64 bit backtrace code I found it useful
to have a simple test module to test a process and irq context backtrace.
Since the existing backtrace code was buggy, I figure it might be useful
to have such a test module in the kernel so that maybe we can even
detect such bugs earlier..
[ mingo@elte.hu: build fix ]
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Arjan van de Ven [Wed, 30 Jan 2008 12:33:07 +0000 (13:33 +0100)]
x86: use the stack frames to get exact stack-traces for CONFIG_FRAMEPOINTER on x86-64
x86 32 bit already has this feature: This patch uses the stack frames with
frame pointer into an exact stack trace, by following the frame pointer.
This only affects kernels built with the CONFIG_FRAME_POINTER config option
enabled, and greatly reduces the amount of noise in oopses.
This code uses the traditional method of doing backtraces, but if it
finds a valid frame pointer chain, will use that to show which parts
of the backtrace are reliable and which parts are not
Due to the fragility and importance of the backtrace code, this needs to
be well reviewed and well tested before merging into mainlne.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Arjan van de Ven [Wed, 30 Jan 2008 12:33:07 +0000 (13:33 +0100)]
x86: turn 64 bit x86 HANDLE_STACK into print_context_stack like 32 bit has
This patch turns the x86 64 bit HANDLE_STACK macro in the backtrace code
into a function, just like 32 bit has. This is needed pre work in order to
get exact backtraces for CONFIG_FRAME_POINTER to work.
The function and it's arguments are not the same as 32 bit; due to the
exception/interrupt stack way of x86-64 there are a few differences.
This patch should not have any behavior changes, only code movement.
Due to the fragility and importance of the backtrace code, this needs to be
well reviewed and well tested before merging into mainlne.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Arjan van de Ven [Wed, 30 Jan 2008 12:33:07 +0000 (13:33 +0100)]
x86: pull bp calculation earlier into the backtrace path
Right now, we take the stack pointer early during the backtrace path, but
only calculate bp several functions deep later, making it hard to reconcile
the stack and bp backtraces (as well as showing several internal backtrace
functions on the stack with bp based backtracing).
This patch moves the bp taking to the same place we take the stack pointer;
sadly this ripples through several layers of the back tracing stack,
but it's not all that bad in the end I hope.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Arjan van de Ven [Wed, 30 Jan 2008 12:33:07 +0000 (13:33 +0100)]
x86: improve the 32 bit Frame Pointer backtracer to also use the traditional backtrace
The 32 bit Frame Pointer backtracer code checks if the EBP is valid
to do a backtrace; however currently on a failure it just gives up
and prints nothing. That's not very nice; we can do better and still
print a decent backtrace.
This patch changes the backtracer to use the regular backtracing algorithm
at the same time as the EBP backtracer; the EBP backtracer is basically
used to figure out which part of the backtrace are reliable vs those
which are likely to be noise.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Arjan van de Ven [Wed, 30 Jan 2008 12:33:07 +0000 (13:33 +0100)]
x86: add the capability to print fuzzy backtraces
For enhancing the 32 bit EBP based backtracer, I need the capability
for the backtracer to tell it's customer that an entry is either
reliable or unreliable, and the backtrace printing code then needs to
print the unreliable ones slightly different.
This patch adds the basic capability, the next patch will add a user
of this capability.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>