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9 commits

Author SHA1 Message Date
Max Filippov
8951eb1530 xtensa: make stack dump size configurable
Introduce Kconfig symbol PRINT_STACK_DEPTH and use it to initialize
kstack_depth_to_print.

Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2019-11-26 11:33:39 -08:00
Christoph Hellwig
06ec64b84c Kconfig: consolidate the "Kernel hacking" menu
Move the source of lib/Kconfig.debug and arch/$(ARCH)/Kconfig.debug to
the top-level Kconfig.  For two architectures that means moving their
arch-specific symbols in that menu into a new arch Kconfig.debug file,
and for a few more creating a dummy file so that we can include it
unconditionally.

Also move the actual 'Kernel hacking' menu to lib/Kconfig.debug, where
it belongs.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-08-02 08:06:48 +09:00
Greg Kroah-Hartman
b24413180f 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>
2017-11-02 11:10:55 +01:00
Chris Zankel
1f2fdbd007 xtensa: disable link optimization
The default linker behavior is to optimize identical literal values
and remove unnecessary overhead. However, because of a bug in the
linker, this currently results in an error ('call target out of range').

Disable link-time optimizations per default until there is a fix
for the linker and add the option to iss_defconfig.

Signed-off-by: Chris Zankel <chris@zankel.net>
2014-12-15 23:47:24 -08:00
Max Filippov
be603092cc xtensa: nommu: add MMU dependency to DEBUG_TLB_SANITY
TLB sanity checking code depends on full MMU presence and may not be
built in noMMU confgiuration.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2014-10-21 13:28:51 +04:00
Max Filippov
a99e07ee5e xtensa: check TLB sanity on return to userspace
- check that user TLB mappings correspond to the current page table;
- check that TLB mapping VPN is in the kernel/user address range
  in accordance with its ASID.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>
2013-07-08 01:18:56 -07:00
Max Filippov
00273125c3 xtensa: add s32c1i sanity check
Add a brief sanity test of S32C1I functionality.  This instruction
is needed by the kernel and userland as part of the base ABI
(including GCC atomic builtins, certain threading packages, future
atomic support in the C++ standard, etc).  However, correct operation
of this instruction requires some cooperation by hardware external to
the processor (such as bus bridge, bus fabric, or memory controller).
Minimally exercising this mechanism and reporting explicit status
early in the boot process is helpful to chip vendors using the Linux
kernel as a benchmark of correctness of hardware.

As it turns out, S32C1I is not exercised by the kernel and by uClibc
based userland as of early June 2008.  This is expected to change
soon as both incorporate more recent open source developments.

Signed-off-by: Marc Gauthier <marc@tensilica.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>
2012-12-18 21:10:22 -08:00
Chris Zankel
6550162200 xtensa: add config option to disable linker relaxation
The default linker behavior is to optimize identical literal values and
remove unnecessary overhead from assembler-generated "longcall" sequences
to reduce code size. Provide an option to disable this behavior to improve
compile time.

Signed-off-by: Chris Zankel <chris@zankel.net>
2012-12-18 21:10:20 -08:00
Chris Zankel
8e1a6dd2fd [PATCH] xtensa: Architecture support for Tensilica Xtensa Part 1
The attached patches provides part 1 of an architecture implementation for the
Tensilica Xtensa CPU series.

Signed-off-by: Chris Zankel <chris@zankel.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-24 00:05:21 -07:00