mirror of
https://github.com/FEX-Emu/linux.git
synced 2024-12-23 18:07:03 +00:00
b24413180f
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>
258 lines
8.7 KiB
Plaintext
258 lines
8.7 KiB
Plaintext
# SPDX-License-Identifier: GPL-2.0
|
||
menu "Kernel hacking"
|
||
|
||
source "lib/Kconfig.debug"
|
||
|
||
config DEBUG_VERBOSE
|
||
bool "Verbose fault messages"
|
||
default y
|
||
select PRINTK
|
||
help
|
||
When a program crashes due to an exception, or the kernel detects
|
||
an internal error, the kernel can print a not so brief message
|
||
explaining what the problem was. This debugging information is
|
||
useful to developers and kernel hackers when tracking down problems,
|
||
but mostly meaningless to other people. This is always helpful for
|
||
debugging but serves no purpose on a production system.
|
||
Most people should say N here.
|
||
|
||
config DEBUG_MMRS
|
||
tristate "Generate Blackfin MMR tree"
|
||
select DEBUG_FS
|
||
help
|
||
Create a tree of Blackfin MMRs via the debugfs tree. If
|
||
you enable this, you will find all MMRs laid out in the
|
||
/sys/kernel/debug/blackfin/ directory where you can read/write
|
||
MMRs directly from userspace. This is obviously just a debug
|
||
feature.
|
||
|
||
config DEBUG_HWERR
|
||
bool "Hardware error interrupt debugging"
|
||
depends on DEBUG_KERNEL
|
||
help
|
||
When enabled, the hardware error interrupt is never disabled, and
|
||
will happen immediately when an error condition occurs. This comes
|
||
at a slight cost in code size, but is necessary if you are getting
|
||
hardware error interrupts and need to know where they are coming
|
||
from.
|
||
|
||
config EXACT_HWERR
|
||
bool "Try to make Hardware errors exact"
|
||
depends on DEBUG_HWERR
|
||
help
|
||
By default, the Blackfin hardware errors are not exact - the error
|
||
be reported multiple cycles after the error happens. This delay
|
||
can cause the wrong application, or even the kernel to receive a
|
||
signal to be killed. If you are getting HW errors in your system,
|
||
try turning this on to ensure they are at least coming from the
|
||
proper thread.
|
||
|
||
On production systems, it is safe (and a small optimization) to say N.
|
||
|
||
config DEBUG_DOUBLEFAULT
|
||
bool "Debug Double Faults"
|
||
default n
|
||
help
|
||
If an exception is caused while executing code within the exception
|
||
handler, the NMI handler, the reset vector, or in emulator mode,
|
||
a double fault occurs. On the Blackfin, this is a unrecoverable
|
||
event. You have two options:
|
||
- RESET exactly when double fault occurs. The excepting
|
||
instruction address is stored in RETX, where the next kernel
|
||
boot will print it out.
|
||
- Print debug message. This is much more error prone, although
|
||
easier to handle. It is error prone since:
|
||
- The excepting instruction is not committed.
|
||
- All writebacks from the instruction are prevented.
|
||
- The generated exception is not taken.
|
||
- The EXCAUSE field is updated with an unrecoverable event
|
||
The only way to check this is to see if EXCAUSE contains the
|
||
unrecoverable event value at every exception return. By selecting
|
||
this option, you are skipping over the faulting instruction, and
|
||
hoping things stay together enough to print out a debug message.
|
||
|
||
This does add a little kernel code, but is the only method to debug
|
||
double faults - if unsure say "Y"
|
||
|
||
choice
|
||
prompt "Double Fault Failure Method"
|
||
default DEBUG_DOUBLEFAULT_PRINT
|
||
depends on DEBUG_DOUBLEFAULT
|
||
|
||
config DEBUG_DOUBLEFAULT_PRINT
|
||
bool "Print"
|
||
|
||
config DEBUG_DOUBLEFAULT_RESET
|
||
bool "Reset"
|
||
|
||
endchoice
|
||
|
||
config DEBUG_HUNT_FOR_ZERO
|
||
bool "Catch NULL pointer reads/writes"
|
||
default y
|
||
help
|
||
Say Y here to catch reads/writes to anywhere in the memory range
|
||
from 0x0000 - 0x0FFF (the first 4k) of memory. This is useful in
|
||
catching common programming errors such as NULL pointer dereferences.
|
||
|
||
Misbehaving applications will be killed (generate a SEGV) while the
|
||
kernel will trigger a panic.
|
||
|
||
Enabling this option will take up an extra entry in CPLB table.
|
||
Otherwise, there is no extra overhead.
|
||
|
||
config DEBUG_BFIN_HWTRACE_ON
|
||
bool "Turn on Blackfin's Hardware Trace"
|
||
default y
|
||
help
|
||
All Blackfins include a Trace Unit which stores a history of the last
|
||
16 changes in program flow taken by the program sequencer. The history
|
||
allows the user to recreate the program sequencer’s recent path. This
|
||
can be handy when an application dies - we print out the execution
|
||
path of how it got to the offending instruction.
|
||
|
||
By turning this off, you may save a tiny amount of power.
|
||
|
||
choice
|
||
prompt "Omit loop Tracing"
|
||
default DEBUG_BFIN_HWTRACE_COMPRESSION_OFF
|
||
depends on DEBUG_BFIN_HWTRACE_ON
|
||
help
|
||
The trace buffer can be configured to omit recording of changes in
|
||
program flow that match either the last entry or one of the last
|
||
two entries. Omitting one of these entries from the record prevents
|
||
the trace buffer from overflowing because of any sort of loop (for, do
|
||
while, etc) in the program.
|
||
|
||
Because zero-overhead Hardware loops are not recorded in the trace buffer,
|
||
this feature can be used to prevent trace overflow from loops that
|
||
are nested four deep.
|
||
|
||
config DEBUG_BFIN_HWTRACE_COMPRESSION_OFF
|
||
bool "Trace all Loops"
|
||
help
|
||
The trace buffer records all changes of flow
|
||
|
||
config DEBUG_BFIN_HWTRACE_COMPRESSION_ONE
|
||
bool "Compress single-level loops"
|
||
help
|
||
The trace buffer does not record single loops - helpful if trace
|
||
is spinning on a while or do loop.
|
||
|
||
config DEBUG_BFIN_HWTRACE_COMPRESSION_TWO
|
||
bool "Compress two-level loops"
|
||
help
|
||
The trace buffer does not record loops two levels deep. Helpful if
|
||
the trace is spinning in a nested loop
|
||
|
||
endchoice
|
||
|
||
config DEBUG_BFIN_HWTRACE_COMPRESSION
|
||
int
|
||
depends on DEBUG_BFIN_HWTRACE_ON
|
||
default 0 if DEBUG_BFIN_HWTRACE_COMPRESSION_OFF
|
||
default 1 if DEBUG_BFIN_HWTRACE_COMPRESSION_ONE
|
||
default 2 if DEBUG_BFIN_HWTRACE_COMPRESSION_TWO
|
||
|
||
|
||
config DEBUG_BFIN_HWTRACE_EXPAND
|
||
bool "Expand Trace Buffer greater than 16 entries"
|
||
depends on DEBUG_BFIN_HWTRACE_ON
|
||
default n
|
||
help
|
||
By selecting this option, every time the 16 hardware entries in
|
||
the Blackfin's HW Trace buffer are full, the kernel will move them
|
||
into a software buffer, for dumping when there is an issue. This
|
||
has a great impact on performance, (an interrupt every 16 change of
|
||
flows) and should normally be turned off, except in those nasty
|
||
debugging sessions
|
||
|
||
config DEBUG_BFIN_HWTRACE_EXPAND_LEN
|
||
int "Size of Trace buffer (in power of 2k)"
|
||
range 0 4
|
||
depends on DEBUG_BFIN_HWTRACE_EXPAND
|
||
default 1
|
||
help
|
||
This sets the size of the software buffer that the trace information
|
||
is kept in.
|
||
0 for (2^0) 1k, or 256 entries,
|
||
1 for (2^1) 2k, or 512 entries,
|
||
2 for (2^2) 4k, or 1024 entries,
|
||
3 for (2^3) 8k, or 2048 entries,
|
||
4 for (2^4) 16k, or 4096 entries
|
||
|
||
config DEBUG_BFIN_NO_KERN_HWTRACE
|
||
bool "Turn off hwtrace in CPLB handlers"
|
||
depends on DEBUG_BFIN_HWTRACE_ON
|
||
default y
|
||
help
|
||
The CPLB error handler contains a lot of flow changes which can
|
||
quickly fill up the hardware trace buffer. When debugging crashes,
|
||
the hardware trace may indicate that the problem lies in kernel
|
||
space when in reality an application is buggy.
|
||
|
||
Say Y here to disable hardware tracing in some known "jumpy" pieces
|
||
of code so that the trace buffer will extend further back.
|
||
|
||
config EARLY_PRINTK
|
||
bool "Early printk"
|
||
default n
|
||
select SERIAL_CORE_CONSOLE
|
||
help
|
||
This option enables special console drivers which allow the kernel
|
||
to print messages very early in the bootup process.
|
||
|
||
This is useful for kernel debugging when your machine crashes very
|
||
early before the console code is initialized. After enabling this
|
||
feature, you must add "earlyprintk=serial,uart0,57600" to the
|
||
command line (bootargs). It is safe to say Y here in all cases, as
|
||
all of this lives in the init section and is thrown away after the
|
||
kernel boots completely.
|
||
|
||
config NMI_WATCHDOG
|
||
bool "Enable NMI watchdog to help debugging lockup on SMP"
|
||
default n
|
||
depends on SMP
|
||
help
|
||
If any CPU in the system does not execute the period local timer
|
||
interrupt for more than 5 seconds, then the NMI handler dumps debug
|
||
information. This information can be used to debug the lockup.
|
||
|
||
config CPLB_INFO
|
||
bool "Display the CPLB information"
|
||
help
|
||
Display the CPLB information via /proc/cplbinfo.
|
||
|
||
config ACCESS_CHECK
|
||
bool "Check the user pointer address"
|
||
default y
|
||
help
|
||
Usually the pointer transfer from user space is checked to see if its
|
||
address is in the kernel space.
|
||
|
||
Say N here to disable that check to improve the performance.
|
||
|
||
config BFIN_ISRAM_SELF_TEST
|
||
bool "isram boot self tests"
|
||
default n
|
||
help
|
||
Run some self tests of the isram driver code at boot.
|
||
|
||
config BFIN_PSEUDODBG_INSNS
|
||
bool "Support pseudo debug instructions"
|
||
default n
|
||
help
|
||
This option allows the kernel to emulate some pseudo instructions which
|
||
allow simulator test cases to be run under Linux with no changes.
|
||
|
||
Most people should say N here.
|
||
|
||
config BFIN_PM_WAKEUP_TIME_BENCH
|
||
bool "Display the total time for kernel to resume from power saving mode"
|
||
default n
|
||
help
|
||
Display the total time when kernel resumes normal from standby or
|
||
suspend to mem mode.
|
||
|
||
endmenu
|