kernel-ark/arch/x86/Kconfig.debug
Linus Torvalds d70b3ef54c Merge branch 'x86-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 core updates from Ingo Molnar:
 "There were so many changes in the x86/asm, x86/apic and x86/mm topics
  in this cycle that the topical separation of -tip broke down somewhat -
  so the result is a more traditional architecture pull request,
  collected into the 'x86/core' topic.

  The topics were still maintained separately as far as possible, so
  bisectability and conceptual separation should still be pretty good -
  but there were a handful of merge points to avoid excessive
  dependencies (and conflicts) that would have been poorly tested in the
  end.

  The next cycle will hopefully be much more quiet (or at least will
  have fewer dependencies).

  The main changes in this cycle were:

   * x86/apic changes, with related IRQ core changes: (Jiang Liu, Thomas
     Gleixner)

     - This is the second and most intrusive part of changes to the x86
       interrupt handling - full conversion to hierarchical interrupt
       domains:

          [IOAPIC domain]   -----
                                 |
          [MSI domain]      --------[Remapping domain] ----- [ Vector domain ]
                                 |   (optional)          |
          [HPET MSI domain] -----                        |
                                                         |
          [DMAR domain]     -----------------------------
                                                         |
          [Legacy domain]   -----------------------------

       This now reflects the actual hardware and allowed us to distangle
       the domain specific code from the underlying parent domain, which
       can be optional in the case of interrupt remapping.  It's a clear
       separation of functionality and removes quite some duct tape
       constructs which plugged the remap code between ioapic/msi/hpet
       and the vector management.

     - Intel IOMMU IRQ remapping enhancements, to allow direct interrupt
       injection into guests (Feng Wu)

   * x86/asm changes:

     - Tons of cleanups and small speedups, micro-optimizations.  This
       is in preparation to move a good chunk of the low level entry
       code from assembly to C code (Denys Vlasenko, Andy Lutomirski,
       Brian Gerst)

     - Moved all system entry related code to a new home under
       arch/x86/entry/ (Ingo Molnar)

     - Removal of the fragile and ugly CFI dwarf debuginfo annotations.
       Conversion to C will reintroduce many of them - but meanwhile
       they are only getting in the way, and the upstream kernel does
       not rely on them (Ingo Molnar)

     - NOP handling refinements. (Borislav Petkov)

   * x86/mm changes:

     - Big PAT and MTRR rework: making the code more robust and
       preparing to phase out exposing direct MTRR interfaces to drivers -
       in favor of using PAT driven interfaces (Toshi Kani, Luis R
       Rodriguez, Borislav Petkov)

     - New ioremap_wt()/set_memory_wt() interfaces to support
       Write-Through cached memory mappings.  This is especially
       important for good performance on NVDIMM hardware (Toshi Kani)

   * x86/ras changes:

     - Add support for deferred errors on AMD (Aravind Gopalakrishnan)

       This is an important RAS feature which adds hardware support for
       poisoned data.  That means roughly that the hardware marks data
       which it has detected as corrupted but wasn't able to correct, as
       poisoned data and raises an APIC interrupt to signal that in the
       form of a deferred error.  It is the OS's responsibility then to
       take proper recovery action and thus prolonge system lifetime as
       far as possible.

     - Add support for Intel "Local MCE"s: upcoming CPUs will support
       CPU-local MCE interrupts, as opposed to the traditional system-
       wide broadcasted MCE interrupts (Ashok Raj)

     - Misc cleanups (Borislav Petkov)

   * x86/platform changes:

     - Intel Atom SoC updates

  ... and lots of other cleanups, fixlets and other changes - see the
  shortlog and the Git log for details"

* 'x86-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (222 commits)
  x86/hpet: Use proper hpet device number for MSI allocation
  x86/hpet: Check for irq==0 when allocating hpet MSI interrupts
  x86/mm/pat, drivers/infiniband/ipath: Use arch_phys_wc_add() and require PAT disabled
  x86/mm/pat, drivers/media/ivtv: Use arch_phys_wc_add() and require PAT disabled
  x86/platform/intel/baytrail: Add comments about why we disabled HPET on Baytrail
  genirq: Prevent crash in irq_move_irq()
  genirq: Enhance irq_data_to_desc() to support hierarchy irqdomain
  iommu, x86: Properly handle posted interrupts for IOMMU hotplug
  iommu, x86: Provide irq_remapping_cap() interface
  iommu, x86: Setup Posted-Interrupts capability for Intel iommu
  iommu, x86: Add cap_pi_support() to detect VT-d PI capability
  iommu, x86: Avoid migrating VT-d posted interrupts
  iommu, x86: Save the mode (posted or remapped) of an IRTE
  iommu, x86: Implement irq_set_vcpu_affinity for intel_ir_chip
  iommu: dmar: Provide helper to copy shared irte fields
  iommu: dmar: Extend struct irte for VT-d Posted-Interrupts
  iommu: Add new member capability to struct irq_remap_ops
  x86/asm/entry/64: Disentangle error_entry/exit gsbase/ebx/usermode code
  x86/asm/entry/32: Shorten __audit_syscall_entry() args preparation
  x86/asm/entry/32: Explain reloading of registers after __audit_syscall_entry()
  ...
2015-06-22 17:59:09 -07:00

359 lines
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menu "Kernel hacking"
config TRACE_IRQFLAGS_SUPPORT
def_bool y
source "lib/Kconfig.debug"
config STRICT_DEVMEM
bool "Filter access to /dev/mem"
---help---
If this option is disabled, you allow userspace (root) access to all
of memory, including kernel and userspace memory. Accidental
access to this is obviously disastrous, but specific access can
be used by people debugging the kernel. Note that with PAT support
enabled, even in this case there are restrictions on /dev/mem
use due to the cache aliasing requirements.
If this option is switched on, the /dev/mem file only allows
userspace access to PCI space and the BIOS code and data regions.
This is sufficient for dosemu and X and all common users of
/dev/mem.
If in doubt, say Y.
config X86_VERBOSE_BOOTUP
bool "Enable verbose x86 bootup info messages"
default y
---help---
Enables the informational output from the decompression stage
(e.g. bzImage) of the boot. If you disable this you will still
see errors. Disable this if you want silent bootup.
config EARLY_PRINTK
bool "Early printk" if EXPERT
default y
---help---
Write kernel log output directly into the VGA buffer or to a serial
port.
This is useful for kernel debugging when your machine crashes very
early before the console code is initialized. For normal operation
it is not recommended because it looks ugly and doesn't cooperate
with klogd/syslogd or the X server. You should normally N here,
unless you want to debug such a crash.
config EARLY_PRINTK_DBGP
bool "Early printk via EHCI debug port"
depends on EARLY_PRINTK && PCI
---help---
Write kernel log output directly into the EHCI debug port.
This is useful for kernel debugging when your machine crashes very
early before the console code is initialized. For normal operation
it is not recommended because it looks ugly and doesn't cooperate
with klogd/syslogd or the X server. You should normally N here,
unless you want to debug such a crash. You need usb debug device.
config EARLY_PRINTK_EFI
bool "Early printk via the EFI framebuffer"
depends on EFI && EARLY_PRINTK
select FONT_SUPPORT
---help---
Write kernel log output directly into the EFI framebuffer.
This is useful for kernel debugging when your machine crashes very
early before the console code is initialized.
config X86_PTDUMP
bool "Export kernel pagetable layout to userspace via debugfs"
depends on DEBUG_KERNEL
select DEBUG_FS
---help---
Say Y here if you want to show the kernel pagetable layout in a
debugfs file. This information is only useful for kernel developers
who are working in architecture specific areas of the kernel.
It is probably not a good idea to enable this feature in a production
kernel.
If in doubt, say "N"
config EFI_PGT_DUMP
bool "Dump the EFI pagetable"
depends on EFI && X86_PTDUMP
---help---
Enable this if you want to dump the EFI page table before
enabling virtual mode. This can be used to debug miscellaneous
issues with the mapping of the EFI runtime regions into that
table.
config DEBUG_RODATA
bool "Write protect kernel read-only data structures"
default y
depends on DEBUG_KERNEL
---help---
Mark the kernel read-only data as write-protected in the pagetables,
in order to catch accidental (and incorrect) writes to such const
data. This is recommended so that we can catch kernel bugs sooner.
If in doubt, say "Y".
config DEBUG_RODATA_TEST
bool "Testcase for the DEBUG_RODATA feature"
depends on DEBUG_RODATA
default y
---help---
This option enables a testcase for the DEBUG_RODATA
feature as well as for the change_page_attr() infrastructure.
If in doubt, say "N"
config DEBUG_SET_MODULE_RONX
bool "Set loadable kernel module data as NX and text as RO"
depends on MODULES
---help---
This option helps catch unintended modifications to loadable
kernel module's text and read-only data. It also prevents execution
of module data. Such protection may interfere with run-time code
patching and dynamic kernel tracing - and they might also protect
against certain classes of kernel exploits.
If in doubt, say "N".
config DEBUG_NX_TEST
tristate "Testcase for the NX non-executable stack feature"
depends on DEBUG_KERNEL && m
---help---
This option enables a testcase for the CPU NX capability
and the software setup of this feature.
If in doubt, say "N"
config DOUBLEFAULT
default y
bool "Enable doublefault exception handler" if EXPERT
---help---
This option allows trapping of rare doublefault exceptions that
would otherwise cause a system to silently reboot. Disabling this
option saves about 4k and might cause you much additional grey
hair.
config DEBUG_TLBFLUSH
bool "Set upper limit of TLB entries to flush one-by-one"
depends on DEBUG_KERNEL
---help---
X86-only for now.
This option allows the user to tune the amount of TLB entries the
kernel flushes one-by-one instead of doing a full TLB flush. In
certain situations, the former is cheaper. This is controlled by the
tlb_flushall_shift knob under /sys/kernel/debug/x86. If you set it
to -1, the code flushes the whole TLB unconditionally. Otherwise,
for positive values of it, the kernel will use single TLB entry
invalidating instructions according to the following formula:
flush_entries <= active_tlb_entries / 2^tlb_flushall_shift
If in doubt, say "N".
config IOMMU_DEBUG
bool "Enable IOMMU debugging"
depends on GART_IOMMU && DEBUG_KERNEL
depends on X86_64
---help---
Force the IOMMU to on even when you have less than 4GB of
memory and add debugging code. On overflow always panic. And
allow to enable IOMMU leak tracing. Can be disabled at boot
time with iommu=noforce. This will also enable scatter gather
list merging. Currently not recommended for production
code. When you use it make sure you have a big enough
IOMMU/AGP aperture. Most of the options enabled by this can
be set more finegrained using the iommu= command line
options. See Documentation/x86/x86_64/boot-options.txt for more
details.
config IOMMU_STRESS
bool "Enable IOMMU stress-test mode"
---help---
This option disables various optimizations in IOMMU related
code to do real stress testing of the IOMMU code. This option
will cause a performance drop and should only be enabled for
testing.
config IOMMU_LEAK
bool "IOMMU leak tracing"
depends on IOMMU_DEBUG && DMA_API_DEBUG
---help---
Add a simple leak tracer to the IOMMU code. This is useful when you
are debugging a buggy device driver that leaks IOMMU mappings.
config HAVE_MMIOTRACE_SUPPORT
def_bool y
config X86_DECODER_SELFTEST
bool "x86 instruction decoder selftest"
depends on DEBUG_KERNEL && KPROBES
depends on !COMPILE_TEST
---help---
Perform x86 instruction decoder selftests at build time.
This option is useful for checking the sanity of x86 instruction
decoder code.
If unsure, say "N".
#
# IO delay types:
#
config IO_DELAY_TYPE_0X80
int
default "0"
config IO_DELAY_TYPE_0XED
int
default "1"
config IO_DELAY_TYPE_UDELAY
int
default "2"
config IO_DELAY_TYPE_NONE
int
default "3"
choice
prompt "IO delay type"
default IO_DELAY_0X80
config IO_DELAY_0X80
bool "port 0x80 based port-IO delay [recommended]"
---help---
This is the traditional Linux IO delay used for in/out_p.
It is the most tested hence safest selection here.
config IO_DELAY_0XED
bool "port 0xed based port-IO delay"
---help---
Use port 0xed as the IO delay. This frees up port 0x80 which is
often used as a hardware-debug port.
config IO_DELAY_UDELAY
bool "udelay based port-IO delay"
---help---
Use udelay(2) as the IO delay method. This provides the delay
while not having any side-effect on the IO port space.
config IO_DELAY_NONE
bool "no port-IO delay"
---help---
No port-IO delay. Will break on old boxes that require port-IO
delay for certain operations. Should work on most new machines.
endchoice
if IO_DELAY_0X80
config DEFAULT_IO_DELAY_TYPE
int
default IO_DELAY_TYPE_0X80
endif
if IO_DELAY_0XED
config DEFAULT_IO_DELAY_TYPE
int
default IO_DELAY_TYPE_0XED
endif
if IO_DELAY_UDELAY
config DEFAULT_IO_DELAY_TYPE
int
default IO_DELAY_TYPE_UDELAY
endif
if IO_DELAY_NONE
config DEFAULT_IO_DELAY_TYPE
int
default IO_DELAY_TYPE_NONE
endif
config DEBUG_BOOT_PARAMS
bool "Debug boot parameters"
depends on DEBUG_KERNEL
depends on DEBUG_FS
---help---
This option will cause struct boot_params to be exported via debugfs.
config CPA_DEBUG
bool "CPA self-test code"
depends on DEBUG_KERNEL
---help---
Do change_page_attr() self-tests every 30 seconds.
config OPTIMIZE_INLINING
bool "Allow gcc to uninline functions marked 'inline'"
---help---
This option determines if the kernel forces gcc to inline the functions
developers have marked 'inline'. Doing so takes away freedom from gcc to
do what it thinks is best, which is desirable for the gcc 3.x series of
compilers. The gcc 4.x series have a rewritten inlining algorithm and
enabling this option will generate a smaller kernel there. Hopefully
this algorithm is so good that allowing gcc 4.x and above to make the
decision will become the default in the future. Until then this option
is there to test gcc for this.
If unsure, say N.
config DEBUG_NMI_SELFTEST
bool "NMI Selftest"
depends on DEBUG_KERNEL && X86_LOCAL_APIC
---help---
Enabling this option turns on a quick NMI selftest to verify
that the NMI behaves correctly.
This might help diagnose strange hangs that rely on NMI to
function properly.
If unsure, say N.
config DEBUG_IMR_SELFTEST
bool "Isolated Memory Region self test"
default n
depends on INTEL_IMR
---help---
This option enables automated sanity testing of the IMR code.
Some simple tests are run to verify IMR bounds checking, alignment
and overlapping. This option is really only useful if you are
debugging an IMR memory map or are modifying the IMR code and want to
test your changes.
If unsure say N here.
config X86_DEBUG_STATIC_CPU_HAS
bool "Debug alternatives"
depends on DEBUG_KERNEL
---help---
This option causes additional code to be generated which
fails if static_cpu_has() is used before alternatives have
run.
If unsure, say N.
config X86_DEBUG_FPU
bool "Debug the x86 FPU code"
depends on DEBUG_KERNEL
default y
---help---
If this option is enabled then there will be extra sanity
checks and (boot time) debug printouts added to the kernel.
This debugging adds some small amount of runtime overhead
to the kernel.
If unsure, say N.
config PUNIT_ATOM_DEBUG
tristate "ATOM Punit debug driver"
select DEBUG_FS
select IOSF_MBI
---help---
This is a debug driver, which gets the power states
of all Punit North Complex devices. The power states of
each device is exposed as part of the debugfs interface.
The current power state can be read from
/sys/kernel/debug/punit_atom/dev_power_state
endmenu