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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>