kernel/arch/mips/vdso, branch linux-4.15.y

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55Z

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 Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

MIPS: Add DWARF unwinding to assembly

2017-09-06T09:01:52Z

This will allow kdump dumps to work correclty with MIPS and future DWARF unwinding of the stack to give accurate tracebacks. Signed-off-by: Corey Minyard Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/16990/ Signed-off-by: Ralf Baechle

MIPS: VDSO: Avoid use of linux/irqchip/mips-gic.h

2017-09-04T11:53:14Z

Our VDSO code makes use of macros from linux/irqchip/mips-gic.h to provide offsets to register values, but these are trivial offsets to the two 32 bit halves of a 64 bit value. Replace use of the macros with zero (ie. omit adding an offset) and the size of the low 32 bit of the value. This removes our need for linux/irqchip/mips-gic.h & prepares us for it to be removed. Signed-off-by: Paul Burton Acked-by: Marc Zyngier Cc: Jason Cooper Cc: Thomas Gleixner Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/17047/ Signed-off-by: Ralf Baechle

MIPS: CPS: Have asm/mips-cps.h include CM & CPC headers

2017-08-29T22:57:27Z

With Coherence Manager (CM) 3.5 information about the topology of the system, which has previously only been available through & accessed from the CM, is now also provided by the Cluster Power Controller (CPC). This includes a new CPC_CONFIG register mirroring GCR_CONFIG, and similarly a new CPC_Cx_CONFIG register mirroring GCR_Cx_CONFIG. In preparation for adjusting functions such as mips_cm_numcores(), which have previously only needed to access the CM, to also access the CPC this patch modifies the way we use the various CPS headers. Rather than having users include asm/mips-cm.h or asm/mips-cpc.h individually we instead have users include asm/mips-cps.h which in turn includes asm/mips-cm.h & asm/mips-cpc.h. This means that users will gain access to both CM & CPC registers by including one header, and most importantly it makes asm/mips-cps.h an ideal location for helper functions which need to access the various components of the CPS. Signed-off-by: Paul Burton Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/17015/ Patchwork: https://patchwork.linux-mips.org/patch/17217/ Signed-off-by: Ralf Baechle

MIPS: VDSO: Fix clobber lists in fallback code paths

2017-08-07T11:53:25Z

Extend clobber lists to include all GP registers. Fixes: 0b523a85e134 ("MIPS: VDSO: Add implementation of gettimeofday() fallback") Signed-off-by: Miodrag Dinic Signed-off-by: Goran Ferenc Signed-off-by: Aleksandar Markovic Reviewed-by: James Hogan Cc: Bo Hu Cc: Douglas Leung Cc: James Hogan Cc: Jin Qian Cc: Paul Burton Cc: Petar Jovanovic Cc: Raghu Gandham Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/16879/ Signed-off-by: Ralf Baechle

MIPS: VDSO: Fix a mismatch between comment and preprocessor constant

2017-06-29T00:42:30Z

Sync the comment with its preprocessor constant counterpart. Signed-off-by: Aleksandar Markovic Cc: James Hogan Cc: Miodrag Dinic Cc: Paul Burton Cc: Petar Jovanovic Cc: Raghu Gandham Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/16641/ Signed-off-by: Ralf Baechle

MIPS: VDSO: Add implementation of gettimeofday() fallback

2017-06-29T00:42:30Z

This patch adds gettimeofday_fallback() function that wraps assembly invocation of gettimeofday() syscall using __NR_gettimeofday. This function is used if pure VDSO implementation gettimeofday() does not succeed for any reason. Its imeplementation is enclosed in "#ifdef CONFIG_MIPS_CLOCK_VSYSCALL" to be in sync with the similar arrangement for __vdso_gettimeofday(). If syscall invocation via __NR_gettimeofday fails, register a3 will be set. So, after the syscall, register a3 is tested and the return valuem is negated if it's set. Signed-off-by: Goran Ferenc Signed-off-by: Miodrag Dinic Signed-off-by: Aleksandar Markovic Cc: Douglas Leung Cc: James Hogan Cc: Paul Burton Cc: Petar Jovanovic Cc: Raghu Gandham Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/16640/ Signed-off-by: Ralf Baechle

MIPS: VDSO: Add implementation of clock_gettime() fallback

2017-06-29T00:42:29Z

This patch adds clock_gettime_fallback() function that wraps assembly invocation of clock_gettime() syscall using __NR_clock_gettime. This function is used if pure VDSO implementation of clock_gettime() does not succeed for any reason. For example, it is called if the clkid parameter of clock_gettime() is not one of the clkids listed in the switch-case block of the function __vdso_clock_gettime() (one such case for clkid is CLOCK_BOOTIME). If syscall invocation via __NR_clock_gettime fails, register a3 will be set. So, after the syscall, register a3 is tested and the return value is negated if it's set. Signed-off-by: Goran Ferenc Signed-off-by: Miodrag Dinic Signed-off-by: Aleksandar Markovic Cc: Douglas Leung Cc: James Hogan Cc: Paul Burton Cc: Petar Jovanovic Cc: Raghu Gandham Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/16639/ Signed-off-by: Ralf Baechle

MIPS: VDSO: Fix conversions in do_monotonic()/do_monotonic_coarse()

2017-06-29T00:42:29Z

Fix incorrect calculation in do_monotonic() and do_monotonic_coarse() function that in turn caused incorrect values returned by the vdso version of system call clock_gettime() on mips64 if its system clock ID parameter was CLOCK_MONOTONIC or CLOCK_MONOTONIC_COARSE. Consider these variables and their types on mips32 and mips64: tk->wall_to_monotonic.tv_sec s64, s64 (kernel/vdso.c) vdso_data.wall_to_mono_sec u32, u32 (kernel/vdso.c) to_mono_sec u32, u32 (vdso/gettimeofday.c) ts->tv_sec s32, s64 (vdso/gettimeofday.c) For mips64 case, u32 vdso_data.wall_to_mono_sec variable is updated from the 64-bit signed variable tk->wall_to_monotonic.tv_sec (kernel/vdso.c:76) which is a negative number holding the time passed from 1970-01-01 to the time boot started. This 64-bit signed value is currently around 47+ years, in seconds. For instance, let this value be: -1489757461 or 11111111111111111111111111111111 10100111001101000001101011101011 By updating 32-bit vdso_data.wall_to_mono_sec variable, we lose upper 32 bits (signed 1's). to_mono_sec variable is a parameter of do_monotonic() and do_monotonic_coarse() functions which holds vdso_data.wall_to_mono_sec value. Its value needs to be added (or subtracted considering it holds negative value from the tk->wall_to_monotonic.tv_sec) to the current time passed from 1970-01-01 (ts->tv_sec), which is again something like 47+ years, but increased by the time passed from the boot to the current time. ts->tv_sec is 32-bit long in case of 32-bit architecture and 64-bit long in case of 64-bit architecture. Consider the update of ts->tv_sec (vdso/gettimeofday.c:55 & 167): ts->tv_sec += to_mono_sec; mips32 case: This update will be performed correctly, since both ts->tv_sec and to_mono_sec are 32-bit long and the sign in to_mono_sec is preserved. Implicit conversion from u32 to s32 will be done correctly. mips64 case: This update will be wrong, since the implicit conversion will not be done correctly. The reason is that the conversion will be from u32 to s64. This is because to_mono_sec is 32-bit long for both mips32 and mips64 cases and s64..33 bits of converted to_mono_sec variable will be zeros. So, in order to make MIPS64 implementation work properly for MONOTONIC and MONOTONIC_COARSE clock ids on mips64, the size of wall_to_mono_sec variable in mips_vdso_data union and respective parameters in do_monotonic() and do_monotonic_coarse() functions should be changed from u32 to u64. Because of consistency, this size change from u32 and u64 is also done for wall_to_mono_nsec variable and corresponding function parameters. As far as similar situations for other architectures are concerned, let's take a look at arm. Arm has two distinct vdso_data structures for 32-bit & 64-bit cases, and arm's wall_to_mono_sec and wall_to_mono_nsec are u32 for 32-bit and u64 for 64-bit cases. On the other hand, MIPS has only one structure (mips_vdso_data), hence the need for changing the size of above mentioned parameters. Signed-off-by: Goran Ferenc Signed-off-by: Miodrag Dinic Signed-off-by: Aleksandar Markovic Cc: Douglas Leung Cc: James Hogan Cc: Paul Burton Cc: Petar Jovanovic Cc: Raghu Gandham Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/16638/ Signed-off-by: Ralf Baechle

MIPS: VDSO: Explicitly use -fno-asynchronous-unwind-tables

2017-02-17T11:32:12Z

Not every toolchain has -fno-asynchronous-unwind-tables per default on MIPS. This patch specifies the necessary option explicitly for VDSO library build. This prevents the following build failure: GENVDSO arch/mips/vdso/vdso-image.c arch/mips/vdso/genvdso: 'arch/mips/vdso/vdso.so.dbg' contains relocation sections .../arch/mips/vdso/Makefile:84: recipe for target 'arch/mips/vdso/vdso-image.c' failed Signed-off-by: Robert Schiele Signed-off-by: Alexander Sverdlin Cc: Ralf Baechle Cc: "Maciej W. Rozycki" Cc: Alexander Sverdlin Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/15127/ Signed-off-by: James Hogan