OpenCloudOS-Kernel/arch/powerpc/Kconfig.debug

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License cleanup: add SPDX GPL-2.0 license identifier to files with no license Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01 22:07:57 +08:00
# SPDX-License-Identifier: GPL-2.0
config PPC_DISABLE_WERROR
bool "Don't build arch/powerpc code with -Werror"
help
This option tells the compiler NOT to build the code under
arch/powerpc with the -Werror flag (which means warnings
are treated as errors).
Only enable this if you are hitting a build failure in the
arch/powerpc code caused by a warning, and you don't feel
inclined to fix it.
config PPC_WERROR
bool
depends on !PPC_DISABLE_WERROR
default y
config PRINT_STACK_DEPTH
int "Stack depth to print" if DEBUG_KERNEL
default 64
help
This option allows you to set the stack depth that the kernel
prints in stack traces. This can be useful if your display is
too small and stack traces cause important information to
scroll off the screen.
config HCALL_STATS
bool "Hypervisor call instrumentation"
depends on PPC_PSERIES && DEBUG_FS && TRACEPOINTS
help
Adds code to keep track of the number of hypervisor calls made and
the amount of time spent in hypervisor calls. Wall time spent in
each call is always calculated, and if available CPU cycles spent
are also calculated. A directory named hcall_inst is added at the
root of the debugfs filesystem. Within the hcall_inst directory
are files that contain CPU specific call statistics.
This option will add a small amount of overhead to all hypervisor
calls.
config PPC_EMULATED_STATS
bool "Emulated instructions tracking"
depends on DEBUG_FS
help
Adds code to keep track of the number of instructions that are
emulated by the in-kernel emulator. Counters for the various classes
of emulated instructions are available under
powerpc/emulated_instructions/ in the root of the debugfs file
system. Optionally (controlled by
powerpc/emulated_instructions/do_warn in debugfs), rate-limited
warnings can be printed to the console when instructions are
emulated.
config CODE_PATCHING_SELFTEST
bool "Run self-tests of the code-patching code"
depends on DEBUG_KERNEL
config JUMP_LABEL_FEATURE_CHECKS
bool "Enable use of jump label for cpu/mmu_has_feature()"
depends on JUMP_LABEL
default y
help
Selecting this options enables use of jump labels for some internal
feature checks. This should generate more optimal code for those
checks.
config JUMP_LABEL_FEATURE_CHECK_DEBUG
bool "Do extra check on feature fixup calls"
depends on DEBUG_KERNEL && JUMP_LABEL_FEATURE_CHECKS
help
This tries to catch incorrect usage of cpu_has_feature() and
mmu_has_feature() in the code.
If you don't know what this means, say N.
config FTR_FIXUP_SELFTEST
bool "Run self-tests of the feature-fixup code"
depends on DEBUG_KERNEL
config MSI_BITMAP_SELFTEST
bool "Run self-tests of the MSI bitmap code"
depends on DEBUG_KERNEL
config PPC_IRQ_SOFT_MASK_DEBUG
bool "Include extra checks for powerpc irq soft masking"
config XMON
bool "Include xmon kernel debugger"
depends on DEBUG_KERNEL
help
Include in-kernel hooks for the xmon kernel monitor/debugger.
Unless you are intending to debug the kernel, say N here.
Make sure to enable also CONFIG_BOOTX_TEXT on Macs. Otherwise
nothing will appear on the screen (xmon writes directly to the
framebuffer memory).
The cmdline option 'xmon' or 'xmon=early' will drop into xmon
very early during boot. 'xmon=on' will just enable the xmon
debugger hooks. 'xmon=off' will disable the debugger hooks
if CONFIG_XMON_DEFAULT is set.
xmon will print a backtrace on the very first invocation.
'xmon=nobt' will disable this autobacktrace.
config XMON_DEFAULT
bool "Enable xmon by default"
depends on XMON
help
xmon is normally disabled unless booted with 'xmon=on'.
Use 'xmon=off' to disable xmon init during runtime.
config XMON_DISASSEMBLY
bool "Include disassembly support in xmon"
depends on XMON
default y
help
Include support for disassembling in xmon. You probably want
to say Y here, unless you're building for a memory-constrained
system.
config DEBUGGER
bool
depends on KGDB || XMON
default y
config BDI_SWITCH
bool "Include BDI-2000 user context switcher"
depends on DEBUG_KERNEL && PPC32
help
Include in-kernel support for the Abatron BDI2000 debugger.
Unless you are intending to debug the kernel with one of these
machines, say N here.
config BOOTX_TEXT
bool "Support for early boot text console (BootX or OpenFirmware only)"
depends on PPC_BOOK3S
help
Say Y here to see progress messages from the boot firmware in text
mode. Requires either BootX or Open Firmware.
config PPC_EARLY_DEBUG
bool "Early debugging (dangerous)"
help
Say Y to enable some early debugging facilities that may be available
for your processor/board combination. Those facilities are hacks
intended to debug problems early during boot, this should not be
enabled in a production kernel.
Note that enabling this will also cause the kernel default log level
to be pushed to max automatically very early during boot
choice
prompt "Early debugging console"
depends on PPC_EARLY_DEBUG
help
Use the selected console for early debugging. Careful, if you
enable debugging for the wrong type of machine your kernel
_will not boot_.
config PPC_EARLY_DEBUG_BOOTX
bool "BootX or OpenFirmware"
depends on BOOTX_TEXT
help
Select this to enable early debugging for a machine using BootX
or OpenFirmware.
config PPC_EARLY_DEBUG_LPAR
bool "LPAR HV Console"
depends on PPC_PSERIES && HVC_CONSOLE
help
Select this to enable early debugging for a machine with a HVC
console on vterm 0.
powerpc/pseries: Re-implement HVSI as part of hvc_vio On pseries machines, consoles are provided by the hypervisor using a low level get_chars/put_chars type interface. However, this is really just a transport to the service processor which implements them either as "raw" console (networked consoles, HMC, ...) or as "hvsi" serial ports. The later is a simple packet protocol on top of the raw character interface that is supposed to convey additional "serial port" style semantics. In practice however, all it does is provide a way to read the CD line and set/clear our DTR line, that's it. We currently implement the "raw" protocol as an hvc console backend (/dev/hvcN) and the "hvsi" protocol using a separate tty driver (/dev/hvsi0). However this is quite impractical. The arbitrary difference between the two type of devices has been a major source of user (and distro) confusion. Additionally, there's an additional mini -hvsi implementation in the pseries platform code for our low level debug console and early boot kernel messages, which means code duplication, though that low level variant is impractical as it's incapable of doing the initial protocol negociation to establish the link to the FSP. This essentially replaces the dedicated hvsi driver and the platform udbg code completely by extending the existing hvc_vio backend used in "raw" mode so that: - It now supports HVSI as well - We add support for hvc backend providing tiocm{get,set} - It also provides a udbg interface for early debug and boot console This is overall less code, though this will only be obvious once we remove the old "hvsi" driver, which is still available for now. When the old driver is enabled, the new code still kicks in for the low level udbg console, replacing the old mini implementation in the platform code, it just doesn't provide the higher level "hvc" interface. In addition to producing generally simler code, this has several benefits over our current situation: - The user/distro only has to deal with /dev/hvcN for the hypervisor console, avoiding all sort of confusion that has plagued us in the past - The tty, kernel and low level debug console all use the same code base which supports the full protocol establishment process, thus the console is now available much earlier than it used to be with the old HVSI driver. The kernel console works much earlier and udbg is available much earlier too. Hackers can enable a hard coded very-early debug console as well that works with HVSI (previously that was only supported for the "raw" mode). I've tried to keep the same semantics as hvsi relative to how I react to things like CD changes, with some subtle differences though: - I clear DTR on close if HUPCL is set - Current hvsi triggers a hangup if it detects a up->down transition on CD (you can still open a console with CD down). My new implementation triggers a hangup if the link to the FSP is severed, and severs it upon detecting a up->down transition on CD. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-05-12 11:46:38 +08:00
config PPC_EARLY_DEBUG_LPAR_HVSI
bool "LPAR HVSI Console"
depends on PPC_PSERIES && HVC_CONSOLE
powerpc/pseries: Re-implement HVSI as part of hvc_vio On pseries machines, consoles are provided by the hypervisor using a low level get_chars/put_chars type interface. However, this is really just a transport to the service processor which implements them either as "raw" console (networked consoles, HMC, ...) or as "hvsi" serial ports. The later is a simple packet protocol on top of the raw character interface that is supposed to convey additional "serial port" style semantics. In practice however, all it does is provide a way to read the CD line and set/clear our DTR line, that's it. We currently implement the "raw" protocol as an hvc console backend (/dev/hvcN) and the "hvsi" protocol using a separate tty driver (/dev/hvsi0). However this is quite impractical. The arbitrary difference between the two type of devices has been a major source of user (and distro) confusion. Additionally, there's an additional mini -hvsi implementation in the pseries platform code for our low level debug console and early boot kernel messages, which means code duplication, though that low level variant is impractical as it's incapable of doing the initial protocol negociation to establish the link to the FSP. This essentially replaces the dedicated hvsi driver and the platform udbg code completely by extending the existing hvc_vio backend used in "raw" mode so that: - It now supports HVSI as well - We add support for hvc backend providing tiocm{get,set} - It also provides a udbg interface for early debug and boot console This is overall less code, though this will only be obvious once we remove the old "hvsi" driver, which is still available for now. When the old driver is enabled, the new code still kicks in for the low level udbg console, replacing the old mini implementation in the platform code, it just doesn't provide the higher level "hvc" interface. In addition to producing generally simler code, this has several benefits over our current situation: - The user/distro only has to deal with /dev/hvcN for the hypervisor console, avoiding all sort of confusion that has plagued us in the past - The tty, kernel and low level debug console all use the same code base which supports the full protocol establishment process, thus the console is now available much earlier than it used to be with the old HVSI driver. The kernel console works much earlier and udbg is available much earlier too. Hackers can enable a hard coded very-early debug console as well that works with HVSI (previously that was only supported for the "raw" mode). I've tried to keep the same semantics as hvsi relative to how I react to things like CD changes, with some subtle differences though: - I clear DTR on close if HUPCL is set - Current hvsi triggers a hangup if it detects a up->down transition on CD (you can still open a console with CD down). My new implementation triggers a hangup if the link to the FSP is severed, and severs it upon detecting a up->down transition on CD. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-05-12 11:46:38 +08:00
help
Select this to enable early debugging for a machine with a HVSI
console on a specified vterm.
config PPC_EARLY_DEBUG_G5
bool "Apple G5"
depends on PPC_PMAC64
help
Select this to enable early debugging for Apple G5 machines.
config PPC_EARLY_DEBUG_RTAS_PANEL
bool "RTAS Panel"
depends on PPC_RTAS
help
Select this to enable early debugging via the RTAS panel.
config PPC_EARLY_DEBUG_RTAS_CONSOLE
bool "RTAS Console"
depends on PPC_RTAS
select UDBG_RTAS_CONSOLE
help
Select this to enable early debugging via the RTAS console.
config PPC_EARLY_DEBUG_MAPLE
bool "Maple real mode"
depends on PPC_MAPLE
help
Select this to enable early debugging for Maple.
config PPC_EARLY_DEBUG_PAS_REALMODE
bool "PA Semi real mode"
depends on PPC_PASEMI
help
Select this to enable early debugging for PA Semi.
Output will be on UART0.
config PPC_EARLY_DEBUG_44x
bool "Early serial debugging for IBM/AMCC 44x CPUs"
depends on 44x
help
Select this to enable early debugging for IBM 44x chips via the
inbuilt serial port. If you enable this, ensure you set
PPC_EARLY_DEBUG_44x_PHYSLOW below to suit your target board.
config PPC_EARLY_DEBUG_40x
bool "Early serial debugging for IBM/AMCC 40x CPUs"
depends on 40x
help
Select this to enable early debugging for IBM 40x chips via the
inbuilt serial port. This works on chips with a 16550 compatible
UART. Xilinx chips with uartlite cannot use this option.
config PPC_EARLY_DEBUG_CPM
bool "Early serial debugging for Freescale CPM-based serial ports"
depends on SERIAL_CPM
help
Select this to enable early debugging for Freescale chips
using a CPM-based serial port. This assumes that the bootwrapper
has run, and set up the CPM in a particular way.
config PPC_EARLY_DEBUG_USBGECKO
bool "Early debugging through the USB Gecko adapter"
depends on GAMECUBE_COMMON
select USBGECKO_UDBG
help
Select this to enable early debugging for Nintendo GameCube/Wii
consoles via an external USB Gecko adapter.
config PPC_EARLY_DEBUG_PS3GELIC
bool "Early debugging through the PS3 Ethernet port"
depends on PPC_PS3
select PS3GELIC_UDBG
help
Select this to enable early debugging for the PlayStation3 via
UDP broadcasts sent out through the Ethernet port.
config PPC_EARLY_DEBUG_OPAL_RAW
bool "OPAL raw console"
depends on HVC_OPAL
help
Select this to enable early debugging for the PowerNV platform
using a "raw" console
config PPC_EARLY_DEBUG_OPAL_HVSI
bool "OPAL hvsi console"
depends on HVC_OPAL
help
Select this to enable early debugging for the PowerNV platform
using an "hvsi" console
config PPC_EARLY_DEBUG_MEMCONS
bool "In memory console"
help
Select this to enable early debugging using an in memory console.
This console provides input and output buffers stored within the
kernel BSS and should be safe to select on any system. A debugger
can then be used to read kernel output or send input to the console.
endchoice
config PPC_MEMCONS_OUTPUT_SIZE
int "In memory console output buffer size"
depends on PPC_EARLY_DEBUG_MEMCONS
default 4096
help
Selects the size of the output buffer (in bytes) of the in memory
console.
config PPC_MEMCONS_INPUT_SIZE
int "In memory console input buffer size"
depends on PPC_EARLY_DEBUG_MEMCONS
default 128
help
Selects the size of the input buffer (in bytes) of the in memory
console.
config PPC_EARLY_DEBUG_OPAL
def_bool y
depends on PPC_EARLY_DEBUG_OPAL_RAW || PPC_EARLY_DEBUG_OPAL_HVSI
powerpc/pseries: Re-implement HVSI as part of hvc_vio On pseries machines, consoles are provided by the hypervisor using a low level get_chars/put_chars type interface. However, this is really just a transport to the service processor which implements them either as "raw" console (networked consoles, HMC, ...) or as "hvsi" serial ports. The later is a simple packet protocol on top of the raw character interface that is supposed to convey additional "serial port" style semantics. In practice however, all it does is provide a way to read the CD line and set/clear our DTR line, that's it. We currently implement the "raw" protocol as an hvc console backend (/dev/hvcN) and the "hvsi" protocol using a separate tty driver (/dev/hvsi0). However this is quite impractical. The arbitrary difference between the two type of devices has been a major source of user (and distro) confusion. Additionally, there's an additional mini -hvsi implementation in the pseries platform code for our low level debug console and early boot kernel messages, which means code duplication, though that low level variant is impractical as it's incapable of doing the initial protocol negociation to establish the link to the FSP. This essentially replaces the dedicated hvsi driver and the platform udbg code completely by extending the existing hvc_vio backend used in "raw" mode so that: - It now supports HVSI as well - We add support for hvc backend providing tiocm{get,set} - It also provides a udbg interface for early debug and boot console This is overall less code, though this will only be obvious once we remove the old "hvsi" driver, which is still available for now. When the old driver is enabled, the new code still kicks in for the low level udbg console, replacing the old mini implementation in the platform code, it just doesn't provide the higher level "hvc" interface. In addition to producing generally simler code, this has several benefits over our current situation: - The user/distro only has to deal with /dev/hvcN for the hypervisor console, avoiding all sort of confusion that has plagued us in the past - The tty, kernel and low level debug console all use the same code base which supports the full protocol establishment process, thus the console is now available much earlier than it used to be with the old HVSI driver. The kernel console works much earlier and udbg is available much earlier too. Hackers can enable a hard coded very-early debug console as well that works with HVSI (previously that was only supported for the "raw" mode). I've tried to keep the same semantics as hvsi relative to how I react to things like CD changes, with some subtle differences though: - I clear DTR on close if HUPCL is set - Current hvsi triggers a hangup if it detects a up->down transition on CD (you can still open a console with CD down). My new implementation triggers a hangup if the link to the FSP is severed, and severs it upon detecting a up->down transition on CD. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-05-12 11:46:38 +08:00
config PPC_EARLY_DEBUG_HVSI_VTERMNO
hex "vterm number to use with early debug HVSI"
depends on PPC_EARLY_DEBUG_LPAR_HVSI
default "0x30000000"
help
You probably want 0x30000000 for your first serial port and
0x30000001 for your second one
config PPC_EARLY_DEBUG_OPAL_VTERMNO
hex "vterm number to use with OPAL early debug"
depends on PPC_EARLY_DEBUG_OPAL
default "0"
help
This correspond to which /dev/hvcN you want to use for early
debug.
On OPAL v2, this will be 0 for network console and 1 or 2 for
the machine built-in serial ports.
config PPC_EARLY_DEBUG_44x_PHYSLOW
hex "Low 32 bits of early debug UART physical address"
depends on PPC_EARLY_DEBUG_44x
default "0x40000200"
help
You probably want 0x40000200 for ebony boards and
0x40000300 for taishan
config PPC_EARLY_DEBUG_44x_PHYSHIGH
hex "EPRN of early debug UART physical address"
depends on PPC_EARLY_DEBUG_44x
default "0x1"
config PPC_EARLY_DEBUG_40x_PHYSADDR
hex "Early debug UART physical address"
depends on PPC_EARLY_DEBUG_40x
default "0xef600300"
config PPC_EARLY_DEBUG_CPM_ADDR
hex "CPM UART early debug transmit descriptor address"
depends on PPC_EARLY_DEBUG_CPM
default "0xfa202008" if PPC_EP88XC
default "0xf0001ff8" if CPM2
default "0xff002008" if CPM1
help
This specifies the address of the transmit descriptor
used for early debug output. Because it is needed before
platform probing is done, all platforms selected must
share the same address.
config FAIL_IOMMU
bool "Fault-injection capability for IOMMU"
depends on FAULT_INJECTION
help
Provide fault-injection capability for IOMMU. Each device can
be selectively enabled via the fail_iommu property.
If you are unsure, say N.
config PPC_PTDUMP
bool "Export kernel pagetable layout to userspace via debugfs"
depends on DEBUG_KERNEL && DEBUG_FS
help
This option exports the state of the kernel pagetables to a
debugfs file. This is only useful for kernel developers who are
working in architecture specific areas of the kernel - probably
not a good idea to enable this feature in a production kernel.
If you are unsure, say N.
config PPC_DEBUG_WX
bool "Warn on W+X mappings at boot"
depends on PPC_PTDUMP
help
Generate a warning if any W+X mappings are found at boot.
This is useful for discovering cases where the kernel is leaving
W+X mappings after applying NX, as such mappings are a security risk.
Note that even if the check fails, your kernel is possibly
still fine, as W+X mappings are not a security hole in
themselves, what they do is that they make the exploitation
of other unfixed kernel bugs easier.
There is no runtime or memory usage effect of this option
once the kernel has booted up - it's a one time check.
If in doubt, say "Y".
config PPC_FAST_ENDIAN_SWITCH
bool "Deprecated fast endian-switch syscall"
depends on DEBUG_KERNEL && PPC_BOOK3S_64
help
If you're unsure what this is, say N.
config KASAN_SHADOW_OFFSET
hex
depends on KASAN
default 0xe0000000