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2022-11-21MIPS: Use "grep -E" instead of "egrep"Tiezhu Yang1-1/+1
The latest version of grep claims the egrep is now obsolete so the build now contains warnings that look like: egrep: warning: egrep is obsolescent; using grep -E fix this up by moving the related file to use "grep -E" instead. Here are the steps to install the latest grep: wget http://ftp.gnu.org/gnu/grep/grep-3.8.tar.gz tar xf grep-3.8.tar.gz cd grep-3.8 && ./configure && make sudo make install export PATH=/usr/local/bin:$PATH Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2022-02-07mips: Enable KCSANNemanja Rakovic1-0/+3
This patch enables KCSAN for the 64-bit version. Updated rules for the incompatible compilation units (vdso, boot/compressed). Signed-off-by: Nemanja Rakovic <nemanja.rakovic@syrmia.com> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2021-11-09MIPS: VDSO: remove -nostdlib compiler flagMasahiro Yamada1-1/+1
The -nostdlib option requests the compiler to not use the standard system startup files or libraries when linking. It is effective only when $(CC) is used as a linker driver. Since commit 2ff906994b6c ("MIPS: VDSO: Use $(LD) instead of $(CC) to link VDSO"), $(LD) is directly used, hence -nostdlib is unneeded. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2021-04-21MIPS: Makefile: Replace -pg with CC_FLAGS_FTRACEzhaoxiao1-2/+2
This patch replaces the "open-coded" -pg compile flag with a CC_FLAGS_FTRACE makefile variable which architectures can override if a different option should be used for code generation. Signed-off-by: zhaoxiao <zhaoxiao@uniontech.com> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2021-01-18MIPS: VDSO: Use CLANG_FLAGS instead of filtering out '--target='Nathan Chancellor1-4/+1
Commit ee67855ecd9d ("MIPS: vdso: Allow clang's --target flag in VDSO cflags") allowed the '--target=' flag from the main Makefile to filter through to the vDSO. However, it did not bring any of the other clang specific flags for controlling the integrated assembler and the GNU tools locations (--prefix=, --gcc-toolchain=, and -no-integrated-as). Without these, we will get a warning (visible with tinyconfig): arch/mips/vdso/elf.S:14:1: warning: DWARF2 only supports one section per compilation unit .pushsection .note.Linux, "a",@note ; .balign 4 ; .long 2f - 1f ; .long 4484f - 3f ; .long 0 ; 1:.asciz "Linux" ; 2:.balign 4 ; 3: ^ arch/mips/vdso/elf.S:34:2: warning: DWARF2 only supports one section per compilation unit .section .mips_abiflags, "a" ^ All of these flags are bundled up under CLANG_FLAGS in the main Makefile and exported so that they can be added to Makefiles that set their own CFLAGS. Use this value instead of filtering out '--target=' so there is no warning and all of the tools are properly used. Cc: stable@vger.kernel.org Fixes: ee67855ecd9d ("MIPS: vdso: Allow clang's --target flag in VDSO cflags") Link: https://github.com/ClangBuiltLinux/linux/issues/1256 Reported-by: Anders Roxell <anders.roxell@linaro.org> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Tested-by: Anders Roxell <anders.roxell@linaro.org> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2020-10-09kbuild: explicitly specify the build id styleBill Wendling1-1/+1
ld's --build-id defaults to "sha1" style, while lld defaults to "fast". The build IDs are very different between the two, which may confuse programs that reference them. Signed-off-by: Bill Wendling <morbo@google.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-07-07kbuild: remove cc-option test of -fno-stack-protectorMasahiro Yamada1-2/+1
Some Makefiles already pass -fno-stack-protector unconditionally. For example, arch/arm64/kernel/vdso/Makefile, arch/x86/xen/Makefile. No problem report so far about hard-coding this option. So, we can assume all supported compilers know -fno-stack-protector. GCC 4.8 and Clang support this option (https://godbolt.org/z/_HDGzN) Get rid of cc-option from -fno-stack-protector. Remove CONFIG_CC_HAS_STACKPROTECTOR_NONE, which is always 'y'. Note: arch/mips/vdso/Makefile adds -fno-stack-protector twice, first unconditionally, and second conditionally. I removed the second one. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2020-05-12MIPS: VDSO: Use $(LD) instead of $(CC) to link VDSONathan Chancellor1-9/+4
Currently, the VDSO is being linked through $(CC). This does not match how the rest of the kernel links objects, which is through the $(LD) variable. When clang is built in a default configuration, it first attempts to use the target triple's default linker then the system's default linker, unless told otherwise through -fuse-ld=... We do not use -fuse-ld= because it can be brittle and we have support for invoking $(LD) directly. See commit fe00e50b2db8c ("ARM: 8858/1: vdso: use $(LD) instead of $(CC) to link VDSO") and commit 691efbedc60d2 ("arm64: vdso: use $(LD) instead of $(CC) to link VDSO") for examples of doing this in the VDSO. Do the same thing here. Replace the custom linking logic with $(cmd_ld) and ldflags-y so that $(LD) is respected. We need to explicitly add two flags to the linker that were implicitly passed by the compiler: -G 0 (which comes from ccflags-vdso) and --eh-frame-hdr. Before this patch (generated by adding '-v' to VDSO_LDFLAGS): <gcc_prefix>/libexec/gcc/mips64-linux/9.3.0/collect2 \ -plugin <gcc_prefix>/libexec/gcc/mips64-linux/9.3.0/liblto_plugin.so \ -plugin-opt=<gcc_prefix>/libexec/gcc/mips64-linux/9.3.0/lto-wrapper \ -plugin-opt=-fresolution=/tmp/ccGEi5Ka.res \ --eh-frame-hdr \ -G 0 \ -EB \ -mips64r2 \ -shared \ -melf64btsmip \ -o arch/mips/vdso/vdso.so.dbg.raw \ -L<gcc_prefix>/lib/gcc/mips64-linux/9.3.0/64 \ -L<gcc_prefix>/lib/gcc/mips64-linux/9.3.0 \ -L<gcc_prefix>/lib/gcc/mips64-linux/9.3.0/../../../../mips64-linux/lib \ -Bsymbolic \ --no-undefined \ -soname=linux-vdso.so.1 \ -EB \ --hash-style=sysv \ --build-id \ -T arch/mips/vdso/vdso.lds \ arch/mips/vdso/elf.o \ arch/mips/vdso/vgettimeofday.o \ arch/mips/vdso/sigreturn.o After this patch: <gcc_prefix>/bin/mips64-linux-ld \ -m elf64btsmip \ -Bsymbolic \ --no-undefined \ -soname=linux-vdso.so.1 \ -EB \ -nostdlib \ -shared \ -G 0 \ --eh-frame-hdr \ --hash-style=sysv \ --build-id \ -T arch/mips/vdso/vdso.lds \ arch/mips/vdso/elf.o \ arch/mips/vdso/vgettimeofday.o arch/mips/vdso/sigreturn.o \ -o arch/mips/vdso/vdso.so.dbg.raw Note that we leave behind -mips64r2. Turns out that ld ignores it (see get_emulation in ld/ldmain.c). This is true of current trunk and 2.23, which is the minimum supported version for the kernel: https://sourceware.org/git/?p=binutils-gdb.git;a=blob;f=ld/ldmain.c;hb=aa4209e7b679afd74a3860ce25659e71cc4847d5#l593 https://sourceware.org/git/?p=binutils-gdb.git;a=blob;f=ld/ldmain.c;hb=a55e30b51bc6227d8d41f707654d0a5620978dcf#l641 Before this patch, LD=ld.lld did nothing: $ llvm-readelf -p.comment arch/mips/vdso/vdso.so.dbg | sed 's/(.*//' String dump of section '.comment': [ 0] ClangBuiltLinux clang version 11.0.0 After this patch, it does: $ llvm-readelf -p.comment arch/mips/vdso/vdso.so.dbg | sed 's/(.*//' String dump of section '.comment': [ 0] Linker: LLD 11.0.0 [ 62] ClangBuiltLinux clang version 11.0.0 Link: https://github.com/ClangBuiltLinux/linux/issues/785 Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2020-05-12MIPS: VDSO: Move disabling the VDSO logic to KconfigNathan Chancellor1-28/+2
After commit 9553d16fa671 ("init/kconfig: Add LD_VERSION Kconfig"), we have access to GNU ld's version at configuration time. As a result, we can make it clearer under what configuration circumstances the MIPS VDSO needs to be disabled. This is a prerequisite for getting rid of the MIPS VDSO binutils warning and linking the VDSO when LD is ld.lld. Wrapping the call to ld-ifversion with CONFIG_LD_IS_LLD does not work because the config values are wiped away during 'make clean'. Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2020-02-19MIPS: vdso: Wrap -mexplicit-relocs in cc-optionNathan Chancellor1-1/+1
Clang does not support this option and errors out: clang-11: error: unknown argument: '-mexplicit-relocs' Clang does not appear to need this flag like GCC does because the jalr check that was added in commit 976c23af3ee5 ("mips: vdso: add build time check that no 'jalr t9' calls left") passes just fine with $ make ARCH=mips CC=clang CROSS_COMPILE=mipsel-linux-gnu- malta_defconfig arch/mips/vdso/ even before commit d3f703c4359f ("mips: vdso: fix 'jalr t9' crash in vdso code"). -mrelax-pic-calls has been supported since clang 9, which is the earliest version that could build a working MIPS kernel, and it is the default for clang so just leave it be. Fixes: d3f703c4359f ("mips: vdso: fix 'jalr t9' crash in vdso code") Link: https://github.com/ClangBuiltLinux/linux/issues/890 Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Paul Burton <paulburton@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: clang-built-linux@googlegroups.com
2020-02-15mips: vdso: add build time check that no 'jalr t9' calls leftVictor Kamensky1-1/+7
vdso shared object cannot have GOT based PIC 'jalr t9' calls because nobody set GOT table in vdso. Contributing into vdso .o files are compiled in PIC mode and as result for internal static functions calls compiler will generate 'jalr t9' instructions. Those are supposed to be converted into PC relative 'bal' calls by linker when relocation are processed. Mips global GOT entries do have dynamic relocations and they will be caught by cmd_vdso_check Makefile rule. Static PIC calls go through mips local GOT entries that do not have dynamic relocations. For those 'jalr t9' calls could be present but without dynamic relocations and they need to be converted to 'bal' calls by linker. Add additional build time check to make sure that no 'jalr t9' slip through because of some toolchain misconfiguration that prevents 'jalr t9' to 'bal' conversion. Signed-off-by: Victor Kamensky <kamensky@cisco.com> Signed-off-by: Paul Burton <paulburton@kernel.org> Cc: linux-mips@vger.kernel.org Cc: Ralf Baechle <ralf@linux-mips.org> Cc: James Hogan <jhogan@kernel.org> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: bruce.ashfield@gmail.com Cc: richard.purdie@linuxfoundation.org
2020-02-15MIPS: Disable VDSO time functionality on microMIPSPaul Burton1-2/+17
A check we're about to add to pick up on function calls that depend on bogus use of the GOT in the VDSO picked up on instances of such function calls in microMIPS builds. Since the code appears genuinely problematic, and given the relatively small amount of use & testing that microMIPS sees, go ahead & disable the VDSO for microMIPS builds. Signed-off-by: Paul Burton <paulburton@kernel.org>
2020-02-15mips: vdso: fix 'jalr t9' crash in vdso codeVictor Kamensky1-0/+1
Observed that when kernel is built with Yocto mips64-poky-linux-gcc, and mips64-poky-linux-gnun32-gcc toolchain, resulting vdso contains 'jalr t9' instructions in its code and since in vdso case nobody sets GOT table code crashes when instruction reached. On other hand observed that when kernel is built mips-poky-linux-gcc toolchain, the same 'jalr t9' instruction are replaced with PC relative function calls using 'bal' instructions. The difference boils down to -mrelax-pic-calls and -mexplicit-relocs gcc options that gets different default values depending on gcc target triplets and corresponding binutils. -mrelax-pic-calls got enabled by default only in mips-poky-linux-gcc case. MIPS binutils ld relies on R_MIPS_JALR relocation to convert 'jalr t9' into 'bal' and such relocation is generated only if -mrelax-pic-calls option is on. Please note 'jalr t9' conversion to 'bal' can happen only to static functions. These static PIC calls use mips local GOT entries that are supposed to be filled with start of DSO value by run-time linker (missing in VDSO case) and they do not have dynamic relocations. Global mips GOT entries must have dynamic relocations and they should be prevented by cmd_vdso_check Makefile rule. Solution call out -mrelax-pic-calls and -mexplicit-relocs options explicitly while compiling MIPS vdso code. That would get correct and consistent between different toolchains behaviour. Reported-by: Bruce Ashfield <bruce.ashfield@gmail.com> Signed-off-by: Victor Kamensky <kamensky@cisco.com> Signed-off-by: Paul Burton <paulburton@kernel.org> Cc: linux-mips@vger.kernel.org Cc: Ralf Baechle <ralf@linux-mips.org> Cc: James Hogan <jhogan@kernel.org> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: richard.purdie@linuxfoundation.org
2020-02-04kbuild: rename hostprogs-y/always to hostprogs/always-yMasahiro Yamada1-1/+1
In old days, the "host-progs" syntax was used for specifying host programs. It was renamed to the current "hostprogs-y" in 2004. It is typically useful in scripts/Makefile because it allows Kbuild to selectively compile host programs based on the kernel configuration. This commit renames like follows: always -> always-y hostprogs-y -> hostprogs So, scripts/Makefile will look like this: always-$(CONFIG_BUILD_BIN2C) += ... always-$(CONFIG_KALLSYMS) += ... ... hostprogs := $(always-y) $(always-m) I think this makes more sense because a host program is always a host program, irrespective of the kernel configuration. We want to specify which ones to compile by CONFIG options, so always-y will be handier. The "always", "hostprogs-y", "hostprogs-m" will be kept for backward compatibility for a while. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-01-16MIPS: vdso: Define BUILD_VDSO32 when building a 32bit kernelThomas Gleixner1-0/+4
The confinement of the 32bit specific VDSO functions missed to define BUILD_VDSO32 when building a 32bit MIPS kernel: arch/mips/vdso/vgettimeofday.c: In function __vdso_clock_gettime: arch/mips/vdso/vgettimeofday.c:17:9: error: implicit declaration of function __cvdso_clock_gettime32 arch/mips/vdso/vgettimeofday.c: In function __vdso_clock_getres: arch/mips/vdso/vgettimeofday.c:39:9: error: implicit declaration of function __cvdso_clock_getres_time32 Force the define for 32bit builds in the VDSO Makefile. Fixes: bf279849ad59 ("lib/vdso: Build 32 bit specific functions in the right context") Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Paul Burton <paulburton@kernel.org> Link: https://lore.kernel.org/r/87d0bjfaqa.fsf@nanos.tec.linutronix.de
2019-11-11MIPS: allow building with kcov coverageAlexey Khoroshilov1-0/+1
Add ARCH_HAS_KCOV and HAVE_GCC_PLUGINS to MIPS config. Disable instrumentation of vdso to avoid build failure. Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru> Signed-off-by: Paul Burton <paulburton@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: James Hogan <jhogan@kernel.org> Cc: linux-mips@vger.kernel.org Cc: linux-kernel@vger.kernel.org
2019-10-10MIPS: Disable Loongson MMI instructions for kernel buildPaul Burton1-0/+1
GCC 9.x automatically enables support for Loongson MMI instructions when using some -march= flags, and then errors out when -msoft-float is specified with: cc1: error: ‘-mloongson-mmi’ must be used with ‘-mhard-float’ The kernel shouldn't be using these MMI instructions anyway, just as it doesn't use floating point instructions. Explicitly disable them in order to fix the build with GCC 9.x. Signed-off-by: Paul Burton <paul.burton@mips.com> Fixes: 3702bba5eb4f ("MIPS: Loongson: Add GCC 4.4 support for Loongson2E") Fixes: 6f7a251a259e ("MIPS: Loongson: Add basic Loongson 2F support") Fixes: 5188129b8c9f ("MIPS: Loongson-3: Improve -march option and move it to Platform") Cc: Huacai Chen <chenhc@lemote.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: stable@vger.kernel.org # v2.6.32+ Cc: linux-mips@vger.kernel.org
2019-10-02MIPS: VDSO: Fix build for binutils < 2.25Paul Burton1-1/+1
Versions of binutils prior to 2.25 are unable to link our VDSO due to an unsupported R_MIPS_PC32 relocation generated by the ".word _start - ." line of the inline asm in get_vdso_base(). As such, the intent is that when building with binutils older than 2.25 we don't build code for gettimeofday() & friends in the VDSO that rely upon get_vdso_base(). Commit 24640f233b46 ("mips: Add support for generic vDSO") converted us to using generic VDSO infrastructure, and as part of that the gettimeofday() functionality moved to a new vgettimeofday.c file. The check for binutils < 2.25 wasn't updated to handle this new filename, and so it continues trying to remove the old unused filename from the build. The end result is that we try to include the gettimeofday() code in builds that will fail to link. Fix this by updating the binutils < 2.25 case to remove vgettimeofday.c from obj-vdso-y, rather than gettimeofday.c. Signed-off-by: Paul Burton <paul.burton@mips.com> Fixes: 24640f233b46 ("mips: Add support for generic vDSO") Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: linux-mips@vger.kernel.org
2019-07-26mips: vdso: Fix flip/flop vdso building bugVincenzo Frascino1-7/+7
Running "make" on an already compiled kernel tree will rebuild the vdso library even if this has not been modified. $ make GEN Makefile Using linux as source for kernel CALL linux/scripts/atomic/check-atomics.sh CALL linux/scripts/checksyscalls.sh <stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp] CHK include/generated/compile.h VDSO arch/mips/vdso/vdso.so.dbg.raw OBJCOPY arch/mips/vdso/vdso.so.raw GENVDSO arch/mips/vdso/vdso-image.c CC arch/mips/vdso/vdso-image.o AR arch/mips/vdso/built-in.a AR arch/mips/built-in.a CHK include/generated/autoksyms.h GEN .version CHK include/generated/compile.h UPD include/generated/compile.h CC init/version.o AR init/built-in.a LD vmlinux.o MODPOST vmlinux.o MODINFO modules.builtin.modinfo KSYM .tmp_kallsyms1.o KSYM .tmp_kallsyms2.o LD vmlinux SORTEX vmlinux SYSMAP System.map Building modules, stage 2. ITS arch/mips/boot/vmlinux.gz.its OBJCOPY arch/mips/boot/vmlinux.bin MODPOST 7 modules GZIP arch/mips/boot/vmlinux.bin.gz ITB arch/mips/boot/vmlinux.gz.itb The issue is generated by the fact that "if_changed" is called twice in a single target. Fix the build bug merging the two commands into a single function. Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Paul Burton <paul.burton@mips.com>
2019-07-26mips: vdso: Fix source pathVincenzo Frascino1-2/+2
The vdso library for o32 and n32 does not compile compile correctly when building outside of the source tree due to a wrong inclusion path for config-n32-o32-env.c resulting in the error below: cc1: fatal error: arch/mips/vdso/config-n32-o32-env.c: No such file or dnirectory compilation terminated. arch/mips/vdso/Makefile:153: recipe for target 'arch/mips/vdso/vgettimeofday-o32.o' failed make[3]: *** [arch/mips/vdso/vgettimeofday-o32.o] Error 1 scripts/Makefile.build:490: recipe for target 'arch/mips/vdso' failed Fix the config-n32-o32-env.c inclusion path prepending the $(srctree) variable. Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> [paul.burton@mips.com: Note that this occurs specifically when building outside of the source tree.] Signed-off-by: Paul Burton <paul.burton@mips.com>
2019-07-25mips: Add support for generic vDSOVincenzo Frascino1-3/+30
The mips vDSO library requires some adaptations to take advantage of the newly introduced generic vDSO library. Introduce the following changes: - Modification of vdso.c to be compliant with the common vdso datapage - Use of lib/vdso for gettimeofday Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@mips.com> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> [paul.burton@mips.com: Prepend $(src) to config-n32-o32-env.c path.] Signed-off-by: Paul Burton <paul.burton@mips.com>
2019-04-23mips: vdso: drop unnecessary cc-ldoptionNick Desaulniers1-3/+1
Towards the goal of removing cc-ldoption, it seems that --hash-style= was added to binutils 2.17.50.0.2 in 2006. The minimal required version of binutils for the kernel according to Documentation/process/changes.rst is 2.20. --build-id was added in 2.18 according to binutils-gdb/ld/NEWS. Link: https://gcc.gnu.org/ml/gcc/2007-01/msg01141.html Cc: clang-built-linux@googlegroups.com Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: ralf@linux-mips.org Cc: jhogan@kernel.org Cc: Matt Redfearn <matt.redfearn@mips.com> Cc: Joel Stanley <joel@jms.id.au> Cc: Hassan Naveed <hnaveed@wavecomp.com> Cc: linux-mips@vger.kernel.org Cc: linux-kernel@vger.kernel.org
2019-01-29MIPS: VDSO: Include $(ccflags-vdso) in o32,n32 .lds buildsPaul Burton1-2/+2
When generating vdso-o32.lds & vdso-n32.lds for use with programs running as compat ABIs under 64b kernels, we previously haven't included the compiler flags that are supposedly common to all ABIs - ie. those in the ccflags-vdso variable. This is problematic in cases where we need to provide the -m%-float flag in order to ensure that we don't attempt to use a floating point ABI that's incompatible with the target CPU & ABI. For example a toolchain using current gcc trunk configured --with-fp-32=xx fails to build a 64r6el_defconfig kernel with the following error: cc1: error: '-march=mips1' requires '-mfp32' make[2]: *** [arch/mips/vdso/Makefile:135: arch/mips/vdso/vdso-o32.lds] Error 1 Include $(ccflags-vdso) for the compat VDSO .lds builds, just as it is included for the native VDSO .lds & when compiling objects for the compat VDSOs. This ensures we consistently provide the -msoft-float flag amongst others, avoiding the problem by ensuring we're agnostic to the toolchain defaults. Signed-off-by: Paul Burton <paul.burton@mips.com> Fixes: ebb5e78cc634 ("MIPS: Initial implementation of a VDSO") Cc: linux-mips@vger.kernel.org Cc: Kevin Hilman <khilman@baylibre.com> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Maciej W . Rozycki <macro@linux-mips.org> Cc: stable@vger.kernel.org # v4.4+
2019-01-29MIPS: VDSO: Use same -m%-float cflag as the kernel properPaul Burton1-0/+1
The MIPS VDSO build currently doesn't provide the -msoft-float flag to the compiler as the kernel proper does. This results in an attempt to use the compiler's default floating point configuration, which can be problematic in cases where this is incompatible with the target CPU's -march= flag. For example decstation_defconfig fails to build using toolchains in which gcc was configured --with-fp-32=xx with the following error: LDS arch/mips/vdso/vdso.lds cc1: error: '-march=r3000' requires '-mfp32' make[2]: *** [scripts/Makefile.build:379: arch/mips/vdso/vdso.lds] Error 1 The kernel proper avoids this error because we build with the -msoft-float compiler flag, rather than using the compiler's default. Pass this flag through to the VDSO build so that it too becomes agnostic to the toolchain's floating point configuration. Note that this is filtered out from KBUILD_CFLAGS rather than simply always using -msoft-float such that if we switch the kernel to use -mno-float in the future the VDSO will automatically inherit the change. The VDSO doesn't actually include any floating point code, and its .MIPS.abiflags section is already manually generated to specify that it's compatible with any floating point ABI. As such this change should have no effect on the resulting VDSO, apart from fixing the build failure for affected toolchains. Signed-off-by: Paul Burton <paul.burton@mips.com> Reported-by: Kevin Hilman <khilman@baylibre.com> Reported-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Kevin Hilman <khilman@baylibre.com> References: https://lore.kernel.org/linux-mips/1477843551-21813-1-git-send-email-linux@roeck-us.net/ References: https://kernelci.org/build/id/5c4e4ae059b5142a249ad004/logs/ Fixes: ebb5e78cc634 ("MIPS: Initial implementation of a VDSO") Cc: Maciej W. Rozycki <macro@linux-mips.org> Cc: linux-mips@vger.kernel.org Cc: stable@vger.kernel.org # v4.4+
2018-11-20MIPS: Enable Undefined Behavior Sanitizer UBSANHassan Naveed1-0/+1
Select ARCH_HAS_UBSAN_SANITIZE_ALL in order to allow the user to enable CONFIG_UBSAN_SANITIZE_ALL and instrument the entire kernel for ubsan checks. We exclude the VDSO from this because its build doesn't include the __ubsan_handle_*() functions that the kernel proper defines in from lib/ubsan.c, and the VDSO would have no sane way to report errors even if it had definitions of these functions. Signed-off-by: Hassan Naveed <hnaveed@wavecomp.com> Reviewed-by: Paul Burton <paul.burton@mips.com> Signed-off-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/21179/ Cc: <linux-mips@linux-mips.org>
2018-11-02kbuild: replace cc-name test with CONFIG_CC_IS_CLANGMasahiro Yamada1-1/+1
Evaluating cc-name invokes the compiler every time even when you are not compiling anything, like 'make help'. This is not efficient. The compiler type has been already detected in the Kconfig stage. Use CONFIG_CC_IS_CLANG, instead. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Acked-by: Paul Burton <paul.burton@mips.com> (MIPS) Acked-by: Joel Stanley <joel@jms.id.au>
2018-08-07MIPS: VDSO: Force link endiannessPaul Burton1-0/+1
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 Burton1-0/+5
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
2018-07-27MIPS: VDSO: Prevent use of smp_processor_id()Paul Burton1-1/+2
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
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman1-0/+1
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>
2017-02-17MIPS: VDSO: Explicitly use -fno-asynchronous-unwind-tablesRobert Schiele1-0/+1
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 Bergmann1-2/+5
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 Hogan1-2/+0
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 Hogan1-1/+1
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 Hogan1-0/+1
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. Rozycki1-1/+2
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 Hogan1-12/+28
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 Hogan1-1/+1
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 Roeck1-1/+1
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 Yousef1-2/+2
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: Initial implementation of a VDSOAlex Smith1-0/+160
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>