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2018-08-07MIPS: VDSO: Force link endiannessPaul Burton
When building the VDSO with clang it appears to invoke ld without specifying endianness, even though clang itself was provided with a -EB or -EL flag. This results in the build failing due to a mismatch between the objects that are the input to ld, and the output it is attempting to create: VDSO arch/mips/vdso/vdso.so.dbg.raw mips-linux-ld: arch/mips/vdso/elf.o: compiled for a big endian system and target is little endian mips-linux-ld: arch/mips/vdso/elf.o: endianness incompatible with that of the selected emulation mips-linux-ld: failed to merge target specific data of file arch/mips/vdso/elf.o ... Work around this problem by explicitly specifying the link endianness using -Wl,-EB or -Wl,-EL when -EB or -EL are part of KBUILD_CFLAGS. This resolves the build failure when using clang, and doesn't have any negative effect on gcc. Signed-off-by: Paul Burton <paul.burton@mips.com>
2018-08-06MIPS: vdso: Allow clang's --target flag in VDSO cflagsPaul Burton
The MIPS VDSO code filters out a subset of known-good flags from KBUILD_CFLAGS to use when building VDSO libraries. When we build using clang we need to allow the --target flag through, otherwise we'll generally attempt to build the VDSO for the architecture of the build machine rather than for MIPS. Signed-off-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/20154/ Cc: James Hogan <jhogan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org
2018-08-06MIPS: genvdso: Remove GOT checksPaul Burton
Our genvdso tool performs some rather paranoid checking that the VDSO library isn't attempting to make use of a GOT by constraining the number of entries that the GOT is allowed to contain to the minimum 2 entries that are always generated by binutils. Unfortunately lld prior to revision 334390 generates a third entry, which is unused & thus harmless but falls foul of genvdso's checks & causes the build to fail. Since we already check that the VDSO contains no relocations it seems reasonable to presume that it also doesn't contain use of a GOT, which would involve relocations. Thus rather than attempting to work around this issue by allowing 3 GOT entries when using lld, simply remove the GOT checks which seem overly paranoid. Signed-off-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/20152/ Cc: James Hogan <jhogan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org
2018-07-27MIPS: VDSO: Prevent use of smp_processor_id()Paul Burton
VDSO code should not be using smp_processor_id(), since it is executed in user mode. Introduce a VDSO-specific path which will cause a compile-time or link-time error (depending upon support for __compiletime_error) if the VDSO ever incorrectly attempts to use smp_processor_id(). [Matt Redfearn <matt.redfearn@imgtec.com>: Move before change to smp_processor_id in series] Signed-off-by: Paul Burton <paul.burton@mips.com> Signed-off-by: Matt Redfearn <matt.redfearn@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/17932/ Cc: Ralf Baechle <ralf@linux-mips.org> Cc: James Hogan <jhogan@kernel.org> Cc: linux-mips@linux-mips.org
2018-03-09MIPS: VDSO: Replace __mips_isa_rev with MIPS_ISA_REVMatt Redfearn
Remove the need to check that __mips_isa_rev is defined by using the newly added MIPS_ISA_REV. Signed-off-by: Matt Redfearn <matt.redfearn@mips.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@mips.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/18678/ Signed-off-by: James Hogan <jhogan@kernel.org>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
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>
2017-09-06MIPS: Add DWARF unwinding to assemblyCorey Minyard
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 <cminyard@mvista.com> 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 <ralf@linux-mips.org>
2017-09-04MIPS: VDSO: Avoid use of linux/irqchip/mips-gic.hPaul Burton
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 <paul.burton@imgtec.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Cc: Jason Cooper <jason@lakedaemon.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/17047/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-08-30MIPS: CPS: Have asm/mips-cps.h include CM & CPC headersPaul Burton
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 <paul.burton@imgtec.com> 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 <ralf@linux-mips.org>
2017-08-07MIPS: VDSO: Fix clobber lists in fallback code pathsGoran Ferenc
Extend clobber lists to include all GP registers. Fixes: 0b523a85e134 ("MIPS: VDSO: Add implementation of gettimeofday() fallback") Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com> Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com> Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: Bo Hu <bohu@google.com> Cc: Douglas Leung <douglas.leung@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Jin Qian <jinqian@google.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Petar Jovanovic <petar.jovanovic@imgtec.com> Cc: Raghu Gandham <raghu.gandham@imgtec.com> 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 <ralf@linux-mips.org>
2017-06-29MIPS: VDSO: Fix a mismatch between comment and preprocessor constantAleksandar Markovic
Sync the comment with its preprocessor constant counterpart. Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Miodrag Dinic <miodrag.dinic@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Petar Jovanovic <petar.jovanovic@imgtec.com> Cc: Raghu Gandham <raghu.gandham@imgtec.com> 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 <ralf@linux-mips.org>
2017-06-29MIPS: VDSO: Add implementation of gettimeofday() fallbackGoran Ferenc
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 <goran.ferenc@imgtec.com> Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com> Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com> Cc: Douglas Leung <douglas.leung@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Petar Jovanovic <petar.jovanovic@imgtec.com> Cc: Raghu Gandham <raghu.gandham@imgtec.com> 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 <ralf@linux-mips.org>
2017-06-29MIPS: VDSO: Add implementation of clock_gettime() fallbackGoran Ferenc
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 <goran.ferenc@imgtec.com> Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com> Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com> Cc: Douglas Leung <douglas.leung@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Petar Jovanovic <petar.jovanovic@imgtec.com> Cc: Raghu Gandham <raghu.gandham@imgtec.com> 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 <ralf@linux-mips.org>
2017-06-29MIPS: VDSO: Fix conversions in do_monotonic()/do_monotonic_coarse()Goran Ferenc
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 <goran.ferenc@imgtec.com> Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com> Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com> Cc: Douglas Leung <douglas.leung@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Petar Jovanovic <petar.jovanovic@imgtec.com> Cc: Raghu Gandham <raghu.gandham@imgtec.com> 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 <ralf@linux-mips.org>
2017-02-17MIPS: VDSO: Explicitly use -fno-asynchronous-unwind-tablesRobert Schiele
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 <rschiele@gmail.com> Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: "Maciej W. Rozycki" <macro@imgtec.com> Cc: Alexander Sverdlin <alexander.sverdlin@nokia.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/15127/ Signed-off-by: James Hogan <james.hogan@imgtec.com>
2017-01-24MIPS: Fix modversionsArnd Bergmann
kernelci.org reports tons of build warnings for linux-next: 35 WARNING: "memcpy" [fs/fat/msdos.ko] has no CRC! 35 WARNING: "__copy_user" [fs/fat/fat.ko] has no CRC! 32 WARNING: EXPORT symbol "memset" [vmlinux] version generation failed, symbol will not be versioned. 32 WARNING: EXPORT symbol "copy_page" [vmlinux] version generation failed, symbol will not be versioned. 32 WARNING: EXPORT symbol "clear_page" [vmlinux] version generation failed, symbol will not be versioned. 32 WARNING: EXPORT symbol "__strncpy_from_user_nocheck_asm" [vmlinux] version generation failed, symbol will not be versioned. The problem here is mainly the missing asm/asm-prototypes.h header file that is supposed to include the prototypes for each symbol that is exported from an assembler file. A second problem is that the asm/uaccess.h header contains some but not all the necessary declarations for the user access helpers. Finally, the vdso build is broken once we add asm/asm-prototypes.h, so we have to fix this at the same time by changing the vdso header. My approach here is to just not look for exported symbols in the VDSO assembler files, as the symbols cannot be exported anyway. Fixes: 576a2f0c5c6d ("MIPS: Export memcpy & memset functions alongside their definitions") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: James Hogan <james.hogan@imgtec.com> Cc: Maciej W. Rozycki <macro@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/15038/ Patchwork: https://patchwork.linux-mips.org/patch/15069/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-10-11MIPS: VDSO: Drop duplicated -I*/-E* aflagsJames Hogan
The aflags-vdso is based on ccflags-vdso, which already contains the -I* and -EL/-EB flags from KBUILD_CFLAGS, but those flags are needlessly added again to aflags-vdso. Drop the duplication. Signed-off-by: James Hogan <james.hogan@imgtec.com> Reported-by: Maciej W. Rozycki <macro@imgtec.com> Reviewed-by: Maciej W. Rozycki <macro@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14369/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-10-11MIPS: Fix -mabi=64 build of vdso.ldsJames Hogan
The native ABI vDSO linker script vdso.lds is built by preprocessing vdso.lds.S, with the native -mabi flag passed in to get the correct ABI definitions. Unfortunately however certain toolchains choke on -mabi=64 without a corresponding compatible -march flag, for example: cc1: error: ‘-march=mips32r2’ is not compatible with the selected ABI scripts/Makefile.build:338: recipe for target 'arch/mips/vdso/vdso.lds' failed Fix this by including ccflags-vdso in the KBUILD_CPPFLAGS for vdso.lds, which includes the appropriate -march flag. Fixes: ebb5e78cc634 ("MIPS: Initial implementation of a VDSO") Signed-off-by: James Hogan <james.hogan@imgtec.com> Reviewed-by: Maciej W. Rozycki <macro@imgtec.com> Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org # 4.4.x- Patchwork: https://patchwork.linux-mips.org/patch/14368/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: Build microMIPS VDSO for microMIPS kernelsJames Hogan
MicroMIPS kernels may be expected to run on microMIPS only cores which don't support the normal MIPS instruction set, so be sure to pass the -mmicromips flag through to the VDSO cflags. Fixes: ebb5e78cc634 ("MIPS: Initial implementation of a VDSO") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: <stable@vger.kernel.org> # 4.4.x- Patchwork: https://patchwork.linux-mips.org/patch/13349/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-28MIPS: VDSO: Build with `-fno-strict-aliasing'Maciej W. Rozycki
Avoid an aliasing issue causing a build error in VDSO: In file included from include/linux/srcu.h:34:0, from include/linux/notifier.h:15, from ./arch/mips/include/asm/uprobes.h:9, from include/linux/uprobes.h:61, from include/linux/mm_types.h:13, from ./arch/mips/include/asm/vdso.h:14, from arch/mips/vdso/vdso.h:27, from arch/mips/vdso/gettimeofday.c:11: include/linux/workqueue.h: In function 'work_static': include/linux/workqueue.h:186:2: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing] return *work_data_bits(work) & WORK_STRUCT_STATIC; ^ cc1: all warnings being treated as errors make[2]: *** [arch/mips/vdso/gettimeofday.o] Error 1 with a CONFIG_DEBUG_OBJECTS_WORK configuration and GCC 5.2.0. Include `-fno-strict-aliasing' along with compiler options used, as required for kernel code, fixing a problem present since the introduction of VDSO with commit ebb5e78cc634 ("MIPS: Initial implementation of a VDSO"). Thanks to Tejun for diagnosing this properly! Signed-off-by: Maciej W. Rozycki <macro@imgtec.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Fixes: ebb5e78cc634 ("MIPS: Initial implementation of a VDSO") Cc: Tejun Heo <tj@kernel.org> Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org # v4.3+ Patchwork: https://patchwork.linux-mips.org/patch/13357/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13MIPS: Fix genvdso error on rebuildJames Hogan
The genvdso program modifies the debug and stripped versions of the VDSOs in place, and errors if the modification has already taken place. Unfortunately this means that a rebuild which tries to rerun genvdso to generate vdso*-image.c without also rebuilding vdso.so.dbg (for example if genvdso.c is modified) hits a build error like this: arch/mips/vdso/genvdso 'arch/mips/vdso/vdso.so.dbg' already contains a '.MIPS.abiflags' section This is fixed by reorganising the rules such that unmodified .so files have a .raw suffix, and these are copied in the same rule that runs genvdso on the copies. I.e. previously we had: cmd_vdsold: link objects -> vdso.so.dbg cmd_genvdso: strip vdso.so.dbg -> vdso.so run genvdso -> vdso-image.c and modify vdso.so.dbg and vdso.so in place Now we have: cmd_vdsold: link objects -> vdso.so.dbg.raw a new cmd_objcopy based strip rule (inspired by ARM): strip vdso.so.dbg.raw -> vdso.so.raw cmd_genvdso: copy vdso.so.dbg.raw -> vdso.so.dbg copy vdso.so.raw -> vdso.so run genvdso -> vdso-image.c and modify vdso.so.dbg and vdso.so in place Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13250/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-01-04Fix ld-version.sh to handle large 3rd version partJames Hogan
The ld-version.sh script doesn't handle versions with large (>= 10) 3rd version components, because the 2nd component is only multiplied by 10 times that of the 3rd component. For example the following version string: GNU ld (Codescape GNU Tools 2015.06-05 for MIPS MTI Linux) 2.24.90 gives a bogus version number: 20000000 + 2400000 + 900000 = 23300000 Breakage, confusion and mole-whacking ensues. Increase the multipliers of the first two version components by a factor of 10 to give space for a 3rd components of up to 99, and update the sole user of ld-ifversion (MIPS VDSO) accordingly. Signed-off-by: James Hogan <james.hogan@imgtec.com> Acked-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Andi Kleen <ak@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Michal Marek <mmarek@suse.cz> Cc: Guenter Roeck <linux@roeck-us.net> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/11931/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-12-29MIPS: VDSO: Fix build error with binutils 2.24 and earlierGuenter Roeck
Commit 2a037f310bab ("MIPS: VDSO: Fix build error") tries to fix a build error seen with binutils 2.24 and earlier. However, the fix does not work, and again results in the already known build errors if the kernel is built with an earlier version of binutils. CC arch/mips/vdso/gettimeofday.o /tmp/ccnOVbHT.s: Assembler messages: /tmp/ccnOVbHT.s:50: Error: can't resolve `_start' {*UND* section} - `L0 {.text section} /tmp/ccnOVbHT.s:374: Error: can't resolve `_start' {*UND* section} - `L0 {.text section} scripts/Makefile.build:258: recipe for target 'arch/mips/vdso/gettimeofday.o' failed make[2]: *** [arch/mips/vdso/gettimeofday.o] Error 1 Fixes: 2a037f310bab ("MIPS: VDSO: Fix build error") Cc: Qais Yousef <qais.yousef@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/11926/ Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-12-22MIPS: VDSO: Fix build errorQais Yousef
Commit ebb5e78cc634 ("MIPS: Initial implementation of a VDSO") introduced a build error. For MIPS VDSO to be compiled it requires binutils version 2.25 or above but the check in the Makefile had inverted logic causing it to be compiled in if binutils is below 2.25. This fixes the following compilation error: CC arch/mips/vdso/gettimeofday.o /tmp/ccsExcUd.s: Assembler messages: /tmp/ccsExcUd.s:62: Error: can't resolve `_start' {*UND* section} - `L0' {.text section} /tmp/ccsExcUd.s:467: Error: can't resolve `_start' {*UND* section} - `L0' {.text section} make[2]: *** [arch/mips/vdso/gettimeofday.o] Error 1 make[1]: *** [arch/mips/vdso] Error 2 make: *** [arch/mips] Error 2 [ralf@linux-mips: Fixed Sergei's complaint on the formatting of the cited commit and generally reformatted the log message.] Signed-off-by: Qais Yousef <qais.yousef@imgtec.com> Cc: alex@alex-smith.me.uk Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/11745/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-11-11MIPS: VDSO: Add implementations of gettimeofday() and clock_gettime()Alex Smith
Add user-mode implementations of gettimeofday() and clock_gettime() to the VDSO. This is currently usable with 2 clocksources: the CP0 count register, which is accessible to user-mode via RDHWR on R2 and later cores, or the MIPS Global Interrupt Controller (GIC) timer, which provides a "user-mode visible" section containing a mirror of its counter registers. This section must be mapped into user memory, which is done below the VDSO data page. When a supported clocksource is not in use, the VDSO functions will return -ENOSYS, which causes libc to fall back on the standard syscall path. When support for neither of these clocksources is compiled into the kernel at all, the VDSO still provides clock_gettime(), as the coarse realtime/monotonic clocks can still be implemented. However, gettimeofday() is not provided in this case as nothing can be done without a suitable clocksource. This causes the symbol lookup to fail in libc and it will then always use the standard syscall path. This patch includes a workaround for a bug in QEMU which results in RDHWR on the CP0 count register always returning a constant (incorrect) value. A fix for this has been submitted, and the workaround can be removed after the fix has been in stable releases for a reasonable amount of time. A simple performance test which calls gettimeofday() 1000 times in a loop and calculates the average execution time gives the following results on a Malta + I6400 (running at 20MHz): - Syscall: ~31000 ns - VDSO (GIC): ~15000 ns - VDSO (CP0): ~9500 ns [markos.chandras@imgtec.com: - Minor code re-arrangements in order for mappings to be made in the order they appear to the process' address space. - Move do_{monotonic, realtime} outside of the MIPS_CLOCK_VSYSCALL ifdef - Use gic_get_usm_range so we can do the GIC mapping in the arch/mips/kernel/vdso instead of the GIC irqchip driver] Signed-off-by: Alex Smith <alex.smith@imgtec.com> Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/11338/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-11-11MIPS: Initial implementation of a VDSOAlex Smith
Add an initial implementation of a proper (i.e. an ELF shared library) VDSO. With this commit it does not export any symbols, it only replaces the current signal return trampoline page. A later commit will add user implementations of gettimeofday()/clock_gettime(). To support both new toolchains and old ones which don't generate ABI flags section, we define its content manually and then use a tool (genvdso) to patch up the section to have the correct name and type. genvdso also extracts symbol offsets ({,rt_}sigreturn) needed by the kernel, and generates a C file containing a "struct mips_vdso_image" containing both the VDSO data and these offsets. This C file is compiled into the kernel. On 64-bit kernels we require a different VDSO for each supported ABI, so we may build up to 3 different VDSOs. The VDSO to use is selected by the mips_abi structure. A kernel/user shared data page is created and mapped below the VDSO image. This is currently empty, but will be used by the user time function implementations which are added later. [markos.chandras@imgtec.com: - Add more comments - Move abi detection in genvdso.h since it's the get_symbol function that needs it. - Add an R6 specific way to calculate the base address of VDSO in order to avoid the branch instruction which affects performance. - Do not patch .gnu.attributes since it's not needed for dynamic linking. - Simplify Makefile a little bit. - checkpatch fixes - Restrict VDSO support for binutils < 2.25 for pre-R6 - Include atomic64.h for O32 variant on MIPS64] Signed-off-by: Alex Smith <alex.smith@imgtec.com> Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: Matthew Fortune <matthew.fortune@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/11337/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>