Impact: improve backtrace quality
avoid the confusion in call trace because of the lack of padding at the
tail of function.
When do_exit gets called, the return address behind call instruction is
pushed into stack. If something get wrong in do_exit, for x86_64, the
entry "kernel_execve +0x00/0xXX" rather than "child_rip +0xYY/0xZZ" is
in the call trace.
That looks confusing, so add a u2d to make the return address still part
of the original call site. (This also catches any instances of us returning
from that function somehow.)
Signed-off-by: jia zhang <jia.zhang2008@gmail.com>
Acked-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: make global variables static
Fix these sparse warnings:
arch/x86/boot/video.c:233:3: warning: symbol 'saved' was not declared. Should it be static?
arch/x86/boot/video-vga.c:37:13: warning: symbol 'video_vga' was not declared. Should it be static?
Signed-off-by: Hannes Eder <hannes@hanneseder.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: make ENTRY()/END() macros more capable
It's usefull to catch unbalanced or messed or mixed declarations of ENTRY and
KPROBES. These macros would help a bit.
For example the following code would compile without problems
ENTRY_X86(mcount)
retq
END_X86(mcount)
But if you forget and mess the following form
ENTRY_X86(mcount)
retq
END(mcount)
ENTRY_X86(ftrace_caller)
The assembler will issue the following message:
Error: ENTRY_X86/KPROBE_X86 unbalanced,missed,mixed
Actually the checking is performed at every _X86 macro
so maybe it's good idea to put ENTRY_KPROBE_FINAL_X86
at the end of .S file to be sure you didn't miss anything.
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Alexander van Heukelum <heukelum@mailshack.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
During page sync, if a pagetable contains a self referencing pte (that
points to the pagetable), the corresponding spte may be marked as
writable even though all mappings are supposed to be write protected.
Fix by clearing page unsync before syncing individual sptes.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Impact: move some code out of .kprobes.text
KPROBE_ENTRY switches code generation to .kprobes.text, and KPROBE_END
uses .popsection to get back to the previous section (.text, normally).
Also replace ENDPROC by END, for consistency.
Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup of entry_64.S
Except for the order and the place of the functions, this
patch should not change the generated code.
Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
If an interrupt cannot be injected for some reason (say, page fault
when fetching the IDT descriptor), the interrupt is marked for
reinjection. However, if an NMI is queued at this time, the NMI
will be injected instead and the NMI will be lost.
Fix by deferring the NMI injection until the interrupt has been
injected successfully.
Analyzed by Jan Kiszka.
Signed-off-by: Avi Kivity <avi@redhat.com>
Impact: cleanup
Remove duplicate #define from 'cpufeature.h'.
This also fixes the following sparse warning:
arch/x86/kernel/cpu/capflags.c:54:3: warning: Initializer entry defined twice
arch/x86/kernel/cpu/capflags.c:58:3: also defined here
Signed-off-by: Hannes Eder <hannes@hanneseder.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
Move recently introduced dwarf2 macros to dwarf2.h file.
It allow us to not duplicate them in assembly files.
Active usage of _cfi macros don't make assembly files
more obvious to understand but we already have a lot of
macros there which requires to search the definitions
of them *anyway*. But at least it make every cfi usage
one line shorter.
Also some code alignment is done.
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix MSIx not enough irq numbers available regression
The manual revert of the sparse_irq patches missed to bring the number
of possible irqs back to the .27 status. This resulted in a regression
when two multichannel network cards were placed in a system with only
one IO_APIC - causing the networking driver to not have the right
IRQ and the device not coming up.
Remove the dynamic allocation logic leftovers and simply return
NR_IRQS in probe_nr_irqs() for now.
Fixes: http://lkml.org/lkml/2008/11/19/354
Reported-by: Jesper Dangaard Brouer <hawk@diku.dk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jesper Dangaard Brouer <hawk@diku.dk>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
User stack tracing is just implemented for x86, but it is not x86 specific.
Introduce a generic config flag, that is currently enabled only for x86.
When other arches implement it, they will have to
SELECT USER_STACKTRACE_SUPPORT.
Signed-off-by: Török Edwin <edwintorok@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix sparse build warning
Fix the following sparse warnings:
arch/x86/kernel/cpu/hypervisor.c:37:15: warning: symbol
'get_hypervisor_tsc_freq' was not declared. Should it be static?
arch/x86/kernel/cpu/hypervisor.c:53:16: warning: symbol
'init_hypervisor' was not declared. Should it be static?
Signed-off-by: Hannes Eder <hannes@hanneseder.net>
Cc: "Alok N Kataria" <akataria@vmware.com>
Cc: "Dan Hecht" <dhecht@vmware.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix sparse build warning
Fix the following sparse warnings:
arch/x86/kernel/cpu/vmware.c:69:5: warning: symbol 'vmware_platform'
was not declared. Should it be static?
arch/x86/kernel/cpu/vmware.c:89:15: warning: symbol
'vmware_get_tsc_khz' was not declared. Should it be static?
arch/x86/kernel/cpu/vmware.c:107:16: warning: symbol
'vmware_set_feature_bits' was not declared. Should it be static?
Signed-off-by: Hannes Eder <hannes@hanneseder.net>
Cc: "Alok N Kataria" <akataria@vmware.com>
Cc: "Dan Hecht" <dhecht@vmware.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
Make the headers portion of signal_32.c and signal_64.c the same.
Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: add new (default-off) tracing visualization feature
Usage example:
mount -t debugfs nodev /sys/kernel/debug
cd /sys/kernel/debug/tracing
echo userstacktrace >iter_ctrl
echo sched_switch >current_tracer
echo 1 >tracing_enabled
.... run application ...
echo 0 >tracing_enabled
Then read one of 'trace','latency_trace','trace_pipe'.
To get the best output you can compile your userspace programs with
frame pointers (at least glibc + the app you are tracing).
Signed-off-by: Török Edwin <edwintorok@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: use deeper function tracing depth safely
Some tests showed that function return tracing needed a more deeper depth
of function calls. But it could be unsafe to store these return addresses
to the stack.
So these arrays will now be allocated dynamically into task_struct of current
only when the tracer is activated.
Typical scheme when tracer is activated:
- allocate a return stack for each task in global list.
- fork: allocate the return stack for the newly created task
- exit: free return stack of current
- idle init: same as fork
I chose a default depth of 50. I don't have overruns anymore.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
Simplify the irq-sampled stack overflow debug check:
- eliminate an #idef
- use WARN_ONCE() to emit a single warning (all bets are off
after the first such warning anyway)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: make stack overflow debug check and printout narrower
stack_overflow_check() should consider the stack usage of pt_regs, and
thus it could warn us in advance. Additionally, it looks better for
the warning time to start at INITIAL_JIFFIES.
Assuming that rsp gets close to the check point before interrupt
arrives: when interrupt really happens, thread_info will be partly
overrode.
Signed-off-by: jia zhang <jia.zhang2008@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: Reverts default reboot method.
Checkin 14d7ca5c57 changed the default
reboot method to "pci", a.k.a. port CF9. Unfortunately this has been
shown to cause lockups on at least two systems for which REBOOT_KBD
worked, both Thinkpads with Intel chipsets. This reverts the default
to REBOOT_KBD, while leaving the option to have "reboot=pci" specified
explicitly or via a DMI match.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Impact: fix bootup crash
Even though it tested fine for me, there was still a bug in the
first patch: I have overlooked a call to ptregscall_common. This
patch fixes that, I think, but the code is never executed for
me while running a debian install... (I tested this by putting
an "1:jmp 1b" in there.)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
DISABLE_INTERRUPTS(CLBR_NONE)/TRACE_IRQS_OFF is now always
executed just before paranoid_exit. Move it there.
Split out paranoidzeroentry, paranoiderrorentry, and
paranoidzeroentry_ist to get more readable macro's.
Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup, shrink kernel image size
Also expand the paranoid_exit0 macro into nmi_exit inside the
nmi stub in the case of enabled irq-tracing.
This gives a few hundred bytes code size reduction.
Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
The save_rest function completes a partial stack frame for use
by the PTREGSCALL macro. This also avoids the indirect call in
PTREGSCALLs.
This adds the macro movq_cfi_restore to hide the CFI_RESTORE
annotation when restoring a register from the stack frame.
Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: build fix
The break builds with older binutils (2.16.1):
arch/x86/kernel/entry_64.S: Assembler messages:
arch/x86/kernel/entry_64.S:282: Error: too many positional arguments
arch/x86/kernel/entry_64.S:283: Error: too many positional arguments
arch/x86/kernel/entry_64.S:284: Error: too many positional arguments
arch/x86/kernel/entry_64.S:285: Error: too many positional arguments
arch/x86/kernel/entry_64.S:286: Error: too many positional arguments
arch/x86/kernel/entry_64.S:287: Error: too many positional arguments
arch/x86/kernel/entry_64.S:288: Error: too many positional arguments
arch/x86/kernel/entry_64.S:289: Error: too many positional arguments
arch/x86/kernel/entry_64.S:290: Error: too many positional arguments
Took some time to figure out the detail that GAS chokes on: it's
negative offsets. Rearrange the calculations to make sure we never
go negative.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When we migrate an interrupt from one CPU to another, we set the
move_in_progress flag and clean up the vectors later once they're not
being used. If you're unlucky and call destroy_irq() before the vectors
become un-used, the move_in_progress flag is never cleared, which causes
the interrupt to become unusable.
This was discovered by Jesse Brandeburg for whom it manifested as an
MSI-X device refusing to use MSI-X mode when the driver was unloaded
and reloaded repeatedly.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: uaccess_64: fix return value in __copy_from_user()
x86: quirk for reboot stalls on a Dell Optiplex 330
This add-on patch to x86: move entry_64.S register saving out
of the macros visually cleans up the appearance of the code by
introducing some basic helper macro's. It also adds some cfi
annotations which were missing.
Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Annotate xsave_cntxt_init() as "can be called outside of __init".
Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix incorrect __init annotation
This patch removes the following section mismatch warning. A patch set
was send previously (http://lkml.org/lkml/2008/11/10/407). But
introduce some other problem, reported by Rufus
(http://lkml.org/lkml/2008/11/11/46). Then Ingo Molnar suggest that,
it's best to remove __init from xsave_cntxt_init(void). Which is the
second patch in this series. Now, this one removes the following
warning.
WARNING: arch/x86/kernel/built-in.o(.cpuinit.text+0x2237): Section
mismatch in reference from the function cpu_init() to the function
.init.text:init_thread_xstate()
The function __cpuinit cpu_init() references
a function __init init_thread_xstate().
If init_thread_xstate is only used by cpu_init then
annotate init_thread_xstate with a matching annotation.
Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Here is a combined patch that moves "save_args" out-of-line for
the interrupt macro and moves "error_entry" mostly out-of-line
for the zeroentry and errorentry macros.
The save_args function becomes really straightforward and easy
to understand, with the possible exception of the stack switch
code, which now needs to copy the return address of to the
calling function. Normal interrupts arrive with ((~vector)-0x80)
on the stack, which gets adjusted in common_interrupt:
<common_interrupt>:
(5) addq $0xffffffffffffff80,(%rsp) /* -> ~(vector) */
(4) sub $0x50,%rsp /* space for registers */
(5) callq ffffffff80211290 <save_args>
(5) callq ffffffff80214290 <do_IRQ>
<ret_from_intr>:
...
An apic interrupt stub now look like this:
<thermal_interrupt>:
(5) pushq $0xffffffffffffff05 /* ~(vector) */
(4) sub $0x50,%rsp /* space for registers */
(5) callq ffffffff80211290 <save_args>
(5) callq ffffffff80212b8f <smp_thermal_interrupt>
(5) jmpq ffffffff80211f93 <ret_from_intr>
Similarly the exception handler register saving function becomes
simpler, without the need of any parameter shuffling. The stub
for an exception without errorcode looks like this:
<overflow>:
(6) callq *0x1cad12(%rip) # ffffffff803dd448 <pv_irq_ops+0x38>
(2) pushq $0xffffffffffffffff /* no syscall */
(4) sub $0x78,%rsp /* space for registers */
(5) callq ffffffff8030e3b0 <error_entry>
(3) mov %rsp,%rdi /* pt_regs pointer */
(2) xor %esi,%esi /* no error code */
(5) callq ffffffff80213446 <do_overflow>
(5) jmpq ffffffff8030e460 <error_exit>
And one for an exception with errorcode like this:
<segment_not_present>:
(6) callq *0x1cab92(%rip) # ffffffff803dd448 <pv_irq_ops+0x38>
(4) sub $0x78,%rsp /* space for registers */
(5) callq ffffffff8030e3b0 <error_entry>
(3) mov %rsp,%rdi /* pt_regs pointer */
(5) mov 0x78(%rsp),%rsi /* load error code */
(9) movq $0xffffffffffffffff,0x78(%rsp) /* no syscall */
(5) callq ffffffff80213209 <do_segment_not_present>
(5) jmpq ffffffff8030e460 <error_exit>
Unfortunately, this last type is more than 32 bytes. But the total space
savings due to this patch is about 2500 bytes on an smp-configuration,
and I think the code is clearer than it was before. The tested kernels
were non-paravirt ones (i.e., without the indirect call at the top of
the exception handlers).
Anyhow, I tested this patch on top of a recent -tip. The machine
was an 2x4-core Xeon at 2333MHz. Measured where the delays between
(almost-)adjacent rdtsc instructions. The graphs show how much
time is spent outside of the program as a function of the measured
delay. The area under the graph represents the total time spent
outside the program. Eight instances of the rdtsctest were
started, each pinned to a single cpu. The histogams are added.
For each kernel two measurements were done: one in mostly idle
condition, the other while running "bonnie++ -f", bound to cpu 0.
Each measurement took 40 minutes runtime. See the attached graphs
for the results. The graphs overlap almost everywhere, but there
are small differences.
Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix boot crash on 32-bit
Hiroshi Shimamoto reported a boot failure on 32-bit x86.
The setting of x86_quirks.wakeup_cpu is missing (when
not passing in an explicit apic= boot parameter).
Reported-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
Fix:
arch/x86/kernel/setup.c:592: warning: 'dmi_low_memory_corruption' defined but not used
this is only used if CONFIG_X86_RESERVE_LOW_64K is defined.
Signed-off-by: Richard A. Holden III <aciddeath@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup, reduce size of the kernel image a bit
Fix:
arch/x86/kernel/genx2apic_uv_x.c:403: warning: 'uv_heartbeat_disable' defined but not used
the function is only used when CONFIG_HOTPLUG_CPU is defined.
Signed-off-by: Richard A. Holden III <aciddeath@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'x86/numa' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: make NUMA on 32-bit depend on EXPERIMENTAL again
x86, hibernate: fix breakage on x86_32 with CONFIG_NUMA set
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: more general identifier for Phoenix BIOS
AMD IOMMU: check for next_bit also in unmapped area
AMD IOMMU: fix fullflush comparison length
AMD IOMMU: enable device isolation per default
AMD IOMMU: add parameter to disable device isolation
x86, PEBS/DS: fix code flow in ds_request()
x86: add rdtsc barrier to TSC sync check
xen: fix scrub_page()
x86: fix es7000 compiling
x86, bts: fix unlock problem in ds.c
x86, voyager: fix smp generic helper voyager breakage
x86: move iomap.h to the new include location
