linux.git/arch/mips/kernel/r2300_switch.S, branch for-next Linux kernel source tree mips: remove unneeded #include <asm/export.h> 2023-08-15T08:22:23+00:00 Masahiro Yamada masahiroy@kernel.org 2023-08-07T15:32:41+00:00 122b159d9f1374a7252c927df2b2a575f77de85b There is no EXPORT_SYMBOL line there, hence #include <asm/export.h> is unneeded. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> 
There is no EXPORT_SYMBOL line there, hence #include <asm/export.h>
is unneeded.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Kbuild: rename CC_STACKPROTECTOR[_STRONG] config variables 2018-06-14T03:21:18+00:00 Linus Torvalds torvalds@linux-foundation.org 2018-06-14T03:21:18+00:00 050e9baa9dc9fbd9ce2b27f0056990fc9e0a08a0 The changes to automatically test for working stack protector compiler support in the Kconfig files removed the special STACKPROTECTOR_AUTO option that picked the strongest stack protector that the compiler supported. That was all a nice cleanup - it makes no sense to have the AUTO case now that the Kconfig phase can just determine the compiler support directly. HOWEVER. It also meant that doing "make oldconfig" would now _disable_ the strong stackprotector if you had AUTO enabled, because in a legacy config file, the sane stack protector configuration would look like CONFIG_HAVE_CC_STACKPROTECTOR=y # CONFIG_CC_STACKPROTECTOR_NONE is not set # CONFIG_CC_STACKPROTECTOR_REGULAR is not set # CONFIG_CC_STACKPROTECTOR_STRONG is not set CONFIG_CC_STACKPROTECTOR_AUTO=y and when you ran this through "make oldconfig" with the Kbuild changes, it would ask you about the regular CONFIG_CC_STACKPROTECTOR (that had been renamed from CONFIG_CC_STACKPROTECTOR_REGULAR to just CONFIG_CC_STACKPROTECTOR), but it would think that the STRONG version used to be disabled (because it was really enabled by AUTO), and would disable it in the new config, resulting in: CONFIG_HAVE_CC_STACKPROTECTOR=y CONFIG_CC_HAS_STACKPROTECTOR_NONE=y CONFIG_CC_STACKPROTECTOR=y # CONFIG_CC_STACKPROTECTOR_STRONG is not set CONFIG_CC_HAS_SANE_STACKPROTECTOR=y That's dangerously subtle - people could suddenly find themselves with the weaker stack protector setup without even realizing. The solution here is to just rename not just the old RECULAR stack protector option, but also the strong one. This does that by just removing the CC_ prefix entirely for the user choices, because it really is not about the compiler support (the compiler support now instead automatially impacts _visibility_ of the options to users). This results in "make oldconfig" actually asking the user for their choice, so that we don't have any silent subtle security model changes. The end result would generally look like this: CONFIG_HAVE_CC_STACKPROTECTOR=y CONFIG_CC_HAS_STACKPROTECTOR_NONE=y CONFIG_STACKPROTECTOR=y CONFIG_STACKPROTECTOR_STRONG=y CONFIG_CC_HAS_SANE_STACKPROTECTOR=y where the "CC_" versions really are about internal compiler infrastructure, not the user selections. Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
The changes to automatically test for working stack protector compiler
support in the Kconfig files removed the special STACKPROTECTOR_AUTO
option that picked the strongest stack protector that the compiler
supported.

That was all a nice cleanup - it makes no sense to have the AUTO case
now that the Kconfig phase can just determine the compiler support
directly.

HOWEVER.

It also meant that doing "make oldconfig" would now _disable_ the strong
stackprotector if you had AUTO enabled, because in a legacy config file,
the sane stack protector configuration would look like

  CONFIG_HAVE_CC_STACKPROTECTOR=y
  # CONFIG_CC_STACKPROTECTOR_NONE is not set
  # CONFIG_CC_STACKPROTECTOR_REGULAR is not set
  # CONFIG_CC_STACKPROTECTOR_STRONG is not set
  CONFIG_CC_STACKPROTECTOR_AUTO=y

and when you ran this through "make oldconfig" with the Kbuild changes,
it would ask you about the regular CONFIG_CC_STACKPROTECTOR (that had
been renamed from CONFIG_CC_STACKPROTECTOR_REGULAR to just
CONFIG_CC_STACKPROTECTOR), but it would think that the STRONG version
used to be disabled (because it was really enabled by AUTO), and would
disable it in the new config, resulting in:

  CONFIG_HAVE_CC_STACKPROTECTOR=y
  CONFIG_CC_HAS_STACKPROTECTOR_NONE=y
  CONFIG_CC_STACKPROTECTOR=y
  # CONFIG_CC_STACKPROTECTOR_STRONG is not set
  CONFIG_CC_HAS_SANE_STACKPROTECTOR=y

That's dangerously subtle - people could suddenly find themselves with
the weaker stack protector setup without even realizing.

The solution here is to just rename not just the old RECULAR stack
protector option, but also the strong one.  This does that by just
removing the CC_ prefix entirely for the user choices, because it really
is not about the compiler support (the compiler support now instead
automatially impacts _visibility_ of the options to users).

This results in "make oldconfig" actually asking the user for their
choice, so that we don't have any silent subtle security model changes.
The end result would generally look like this:

  CONFIG_HAVE_CC_STACKPROTECTOR=y
  CONFIG_CC_HAS_STACKPROTECTOR_NONE=y
  CONFIG_STACKPROTECTOR=y
  CONFIG_STACKPROTECTOR_STRONG=y
  CONFIG_CC_HAS_SANE_STACKPROTECTOR=y

where the "CC_" versions really are about internal compiler
infrastructure, not the user selections.

Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02T10:10:55+00:00 Greg Kroah-Hartman gregkh@linuxfoundation.org 2017-11-01T14:07:57+00:00 b24413180f5600bcb3bb70fbed5cf186b60864bd 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> 
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>
MIPS: Remove unused ST_OFF from r2300_switch.S 2017-08-29T13:21:51+00:00 Paul Burton paul.burton@imgtec.com 2017-06-05T18:21:30+00:00 df4c87f5a3d81c7c5518ab08f8642e828e00d469 Commit 1a3d59579b9f ("MIPS: Tidy up FPU context switching") removed usage of ST_OFF, leaving it behind as dead code. Commit 828d1e4e9865 ("MIPS: Remove dead define of ST_OFF") then removed the definition of ST_OFF from r4k_switch.S as a cleanup. However the unused definition of ST_OFF has been left behind in r2300_switch.S. Remove it. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16239/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> 
Commit 1a3d59579b9f ("MIPS: Tidy up FPU context switching") removed
usage of ST_OFF, leaving it behind as dead code. Commit 828d1e4e9865
("MIPS: Remove dead define of ST_OFF") then removed the definition of
ST_OFF from r4k_switch.S as a cleanup. However the unused definition of
ST_OFF has been left behind in r2300_switch.S. Remove it.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16239/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
MIPS: Move r2300 FP code from r2300_switch.S to r2300_fpu.S 2017-08-29T13:21:51+00:00 Paul Burton paul.burton@imgtec.com 2017-06-05T18:21:29+00:00 423fb0d50890dd48907298e7453faaeb5185b814 Move _save_fp(), _restore_fp() & _init_fpu() out of r2300_switch.S & into r2300_fpu.S. This logically places all FP-related asm code into r2300_fpu.S & provides consistency with R4K after the preceding commit. Besides cleaning up this will be useful for later patches which disable FP support. [ralf@linux-mips.org: Fixed build issues reported by Arnd Bergmann <arnd@arndb.de>] Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16238/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> 
Move _save_fp(), _restore_fp() & _init_fpu() out of r2300_switch.S &
into r2300_fpu.S. This logically places all FP-related asm code into
r2300_fpu.S & provides consistency with R4K after the preceding commit.

Besides cleaning up this will be useful for later patches which disable
FP support.

[ralf@linux-mips.org: Fixed build issues reported by Arnd Bergmann
<arnd@arndb.de>]

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16238/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
MIPS: Export _save_fp & _save_msa alongside their definitions 2017-01-03T15:34:49+00:00 Paul Burton paul.burton@imgtec.com 2016-11-07T11:14:10+00:00 29830c124d834c4ce0133aaf8ca85f045f9e758c Now that EXPORT_SYMBOL can be used from assembly source, move the EXPORT_SYMBOL invocations for _save_fp & _save_msa to be alongside their definitions. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14509/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> 
Now that EXPORT_SYMBOL can be used from assembly source, move the
EXPORT_SYMBOL invocations for _save_fp & _save_msa to be alongside their
definitions.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14509/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
MIPS: Fix R2300 FP context switch handling 2015-10-02T17:16:46+00:00 Paul Burton paul.burton@imgtec.com 2015-09-21T17:07:42+00:00 085c2f25d36ef4a69bb1dab933daee0692426f15 Commit 1a3d59579b9f ("MIPS: Tidy up FPU context switching") removed FP context saving from the asm-written resume function in favour of reusing existing code to perform the same task. However it only removed the FP context saving code from the r4k_switch.S implementation of resume. Remove it from the r2300_switch.S implementation too in order to prevent attempting to save the FP context twice, which would likely lead to an exception from the second save because the FPU had already been disabled by the first save. This patch has only been build tested, using rbtx49xx_defconfig. Fixes: 1a3d59579b9f ("MIPS: Tidy up FPU context switching") Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Maciej W. Rozycki <macro@linux-mips.org> Cc: linux-kernel@vger.kernel.org Cc: Manuel Lauss <manuel.lauss@gmail.com> Patchwork: https://patchwork.linux-mips.org/patch/11167/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> 
Commit 1a3d59579b9f ("MIPS: Tidy up FPU context switching") removed FP
context saving from the asm-written resume function in favour of reusing
existing code to perform the same task. However it only removed the FP
context saving code from the r4k_switch.S implementation of resume.
Remove it from the r2300_switch.S implementation too in order to prevent
attempting to save the FP context twice, which would likely lead to an
exception from the second save because the FPU had already been disabled
by the first save.

This patch has only been build tested, using rbtx49xx_defconfig.

Fixes: 1a3d59579b9f ("MIPS: Tidy up FPU context switching")
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-kernel@vger.kernel.org
Cc: Manuel Lauss <manuel.lauss@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/11167/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
MIPS: Respect the ISA level in FCSR handling 2015-04-07T23:10:37+00:00 Maciej W. Rozycki macro@linux-mips.org 2015-04-03T22:27:48+00:00 9b26616c8d9dae53fbac7f7cb2c6dd1308102976 Define the central place the default FCSR value is set from, initialised in `cpu_probe'. Determine the FCSR mask applied to values written to the register with CTC1 in the full emulation mode and via ptrace(2), according to the ISA level of processor hardware or the writability of bits 31:18 if actual FPU hardware is used. Software may rely on FCSR bits whose functions our emulator does not implement, so it should not allow them to be set or software may get confused. For ptrace(2) it's just sanity. [ralf@linux-mips.org: Fixed double inclusion of <asm/current.h>.] Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9711/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> 
Define the central place the default FCSR value is set from, initialised
in `cpu_probe'.  Determine the FCSR mask applied to values written to
the register with CTC1 in the full emulation mode and via ptrace(2),
according to the ISA level of processor hardware or the writability of
bits 31:18 if actual FPU hardware is used.

Software may rely on FCSR bits whose functions our emulator does not
implement, so it should not allow them to be set or software may get
confused.  For ptrace(2) it's just sanity.

[ralf@linux-mips.org: Fixed double inclusion of <asm/current.h>.]

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9711/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
MIPS: Fix build with binutils 2.24.51+ 2014-11-07T14:07:36+00:00 Manuel Lauss manuel.lauss@gmail.com 2014-11-07T13:13:54+00:00 842dfc11ea9a21f9825167c8a4f2834b205b0a79 Starting with version 2.24.51.20140728 MIPS binutils complain loudly about mixing soft-float and hard-float object files, leading to this build failure since GCC is invoked with "-msoft-float" on MIPS: {standard input}: Warning: .gnu_attribute 4,3 requires `softfloat' LD arch/mips/alchemy/common/built-in.o mipsel-softfloat-linux-gnu-ld: Warning: arch/mips/alchemy/common/built-in.o uses -msoft-float (set by arch/mips/alchemy/common/prom.o), arch/mips/alchemy/common/sleeper.o uses -mhard-float To fix this, we detect if GAS is new enough to support "-msoft-float" command option, and if it does, we can let GCC pass it to GAS; but then we also need to sprinkle the files which make use of floating point registers with the necessary ".set hardfloat" directives. Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com> Cc: Linux-MIPS <linux-mips@linux-mips.org> Cc: Matthew Fortune <Matthew.Fortune@imgtec.com> Cc: Markos Chandras <Markos.Chandras@imgtec.com> Cc: Maciej W. Rozycki <macro@linux-mips.org> Patchwork: https://patchwork.linux-mips.org/patch/8355/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> 
Starting with version 2.24.51.20140728 MIPS binutils complain loudly
about mixing soft-float and hard-float object files, leading to this
build failure since GCC is invoked with "-msoft-float" on MIPS:

{standard input}: Warning: .gnu_attribute 4,3 requires `softfloat'
  LD      arch/mips/alchemy/common/built-in.o
mipsel-softfloat-linux-gnu-ld: Warning: arch/mips/alchemy/common/built-in.o
 uses -msoft-float (set by arch/mips/alchemy/common/prom.o),
 arch/mips/alchemy/common/sleeper.o uses -mhard-float

To fix this, we detect if GAS is new enough to support "-msoft-float" command
option, and if it does, we can let GCC pass it to GAS;  but then we also need
to sprinkle the files which make use of floating point registers with the
necessary ".set hardfloat" directives.

Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com>
Cc: Linux-MIPS <linux-mips@linux-mips.org>
Cc: Matthew Fortune <Matthew.Fortune@imgtec.com>
Cc: Markos Chandras <Markos.Chandras@imgtec.com>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Patchwork: https://patchwork.linux-mips.org/patch/8355/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
MIPS: stack protector: Fix per-task canary switch 2013-10-07T13:31:04+00:00 James Hogan james.hogan@imgtec.com 2013-10-07T11:14:26+00:00 8b3c569a3999a8fd5a819f892525ab5520777c92 Commit 1400eb6 (MIPS: r4k,octeon,r2300: stack protector: change canary per task) was merged in v3.11 and introduced assembly in the MIPS resume functions to update the value of the current canary in __stack_chk_guard. However it used PTR_L resulting in a load of the canary value, instead of PTR_LA to construct its address. The value is intended to be random but is then treated as an address in the subsequent LONG_S (store). This was observed to cause a fault and panic: CPU 0 Unable to handle kernel paging request at virtual address 139fea20, epc == 8000cc0c, ra == 8034f2a4 Oops[#1]: ... $24 : 139fea20 1e1f7cb6 ... Call Trace: [<8000cc0c>] resume+0xac/0x118 [<8034f2a4>] __schedule+0x5f8/0x78c [<8034f4e0>] schedule_preempt_disabled+0x20/0x2c [<80348eec>] rest_init+0x74/0x84 [<804dc990>] start_kernel+0x43c/0x454 Code: 3c18804b 8f184030 8cb901f8 <af190000> 00c0e021 8cb002f0 8cb102f4 8cb202f8 8cb302fc This can also be forced by modifying arch/mips/include/asm/stackprotector.h so that the default __stack_chk_guard value is more likely to be a bad (or unaligned) pointer. Fix it to use PTR_LA instead, to load the address of the canary value, which the LONG_S can then use to write into it. Reported-by: bobjones (via #mipslinux on IRC) Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Gregory Fong <gregory.0xf0@gmail.com> Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/6026/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> 
Commit 1400eb6 (MIPS: r4k,octeon,r2300: stack protector: change canary
per task) was merged in v3.11 and introduced assembly in the MIPS resume
functions to update the value of the current canary in
__stack_chk_guard. However it used PTR_L resulting in a load of the
canary value, instead of PTR_LA to construct its address. The value is
intended to be random but is then treated as an address in the
subsequent LONG_S (store).

This was observed to cause a fault and panic:

CPU 0 Unable to handle kernel paging request at virtual address 139fea20, epc == 8000cc0c, ra == 8034f2a4
Oops[#1]:
...
$24   : 139fea20 1e1f7cb6
...
Call Trace:
[<8000cc0c>] resume+0xac/0x118
[<8034f2a4>] __schedule+0x5f8/0x78c
[<8034f4e0>] schedule_preempt_disabled+0x20/0x2c
[<80348eec>] rest_init+0x74/0x84
[<804dc990>] start_kernel+0x43c/0x454
Code: 3c18804b  8f184030  8cb901f8 <af190000> 00c0e021  8cb002f0 8cb102f4  8cb202f8  8cb302fc

This can also be forced by modifying
arch/mips/include/asm/stackprotector.h so that the default
__stack_chk_guard value is more likely to be a bad (or unaligned)
pointer.

Fix it to use PTR_LA instead, to load the address of the canary value,
which the LONG_S can then use to write into it.

Reported-by: bobjones (via #mipslinux on IRC)
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Gregory Fong <gregory.0xf0@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/6026/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>